ALBERT

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): J. Kuljiraseth, A. Wangriya, J. M.C. Malones, W. Klysubun, S. Jitkarnka〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Proven to possess distinguishable physical and acid-base properties superior to conventional LDHs, Aqueous Miscible Organic solvent-Layered Double Hydroxides (AMO-LDHs) were thus synthesized and used as precursors to prepare the Mg/Al mixed oxide catalysts in this work. The AMO-LDH based oxide catalysts with various ratios of Mg/Al were studied for the chemical and physical properties and the activity on esterification of benzoic acid with 2-ethylhexanol. The catalysts were characterized using BET, XRD, TGA, and XPS. Moreover, the acid-base properties were studied by using NH〈sub〉3〈/sub〉-TPD, CO〈sub〉2〈/sub〉-TPD, and X-ray Absorption Spectroscopy (XAS) techniques, both XANES and EXAFS. As a result, the Mg/Al mixed oxides after calcination at 500 °C still had the clay structure, and were found to possess both acid and base sites. As the Mg/Al ratio increased, the total density of acid and basic sites decreased. Moreover, the acid-basic strength depended on their phase compositions and coordination number. The activity of calcined LDHs catalysts was tested for the esterification of benzoic acid with 2-ethylhexanol, aimed at producing 2-ethylhexyl benzoate as the desired chemical. The products were analyzed using GC–MS/TOF. In summary, the conversion of benzoic acid was enhanced significantly using the Mg〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Al mixed oxides as the catalysts, owing to the acid-base sites (both Mg〈sup〉2+〈/sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O〈sup〉2−〈/sup〉 and Al〈sup〉3+〈/sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O〈sup〉2−〈/sup〉 pairs) of the catalysts. The catalyst with the Mg/Al ratio of 4:1 can convert 66% benzoic acid to 2-ethylhexyl benzoate. Moreover, the other products were composed of 2-ethylhexanal, 3-heptanone, and 3-heptanol because of acid-base pairs.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318310440-ga1.jpg" width="269" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Karolina Kinastowska, Jie Liu, John M. Tobin, Yury Rakovich, Filipe Vilela, Zhengtao Xu, Wojciech Bartkowiak, Marek Grzelczak〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Triethanolamine is a widely used model electron donor that enables a fast screening of the photocatalyst parameters in both, homogeneous and heterogeneous scenarios. We report a new role of triethanolamine in heterogeneous photoregeneration of cofactor molecules – nicotinamide adenine dinucleotide (NADH) – using state-of-the-art heterogeneous photocatalysts. In contrast to the common model involving the light-induced electrons and holes generation to reduce the substrate and oxidize triethanolamine simultaneously, we identified glycolaldehyde as a stable product of triethanolamine degradation capable of reducing NAD〈sup〉+〈/sup〉. Triethanolamine, apart from playing a role of a precursor for reducing agent, maintains the alkalinity of the solution to drive the reduction. Our findings offer a fresh insight into the triethanolamine-assisted photocatalysis because glycolaldehyde as such have generally been neglected in mechanistic considerations. Moreover, a spatial and temporal decoupling of the photocatalyst from the substrate reduction reaction minimizes the product re-oxidation, thus implying a relevant feature for the real-world applications using a continuous flow setting.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318310488-ga1.jpg" width="396" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Rizki Insyani, Deepak Verma, Handi Setiadi Cahyadi, Seung Min Kim, Seok Ki Kim, Neha Karanwal, Jaehoon Kim〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Tandem heterogenous catalysis of bimetallic Cu-Pd on UiO-66(NH〈sub〉2〈/sub〉) that were incorporated into sulfonated graphene oxide (Cu-Pd/UiO-66(NH〈sub〉2〈/sub〉)@SGO or Cu-Pd/US) was investigated for the one-pot, direct conversion of di- and polysaccharides into 2,5-dimethylfuran (2,5-DMF) without separation of reaction intermediates. In the absence of a homogeneous acidic catalyst, consecutive reactions of glycosidic bond cleavage, isomerization, dehydration, and hydrogenation/hydrogenolysis were preceded by the synergistic effect of a multifunctional Cu-Pd/US catalyst. The strength and ratio of Brønsted and Lewis acid sites by adjusting UiO-66(NH〈sub〉2〈/sub〉) to SGO ratios resulted in high-yield 5-(hydroxymethyl)furfural (5-HMF) through sequential glycosidic bond cleavage, isomerization, and dehydration of sucrose. Unlike monometallic Cu and Pd, bimetallic Cu-Pd promoted consecutive C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉OH hydrogenolysis and C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉O hydrogenation of reaction intermediates, producing 2,5-DMF with a high yield of 73.4% during the one-pot conversion of sucrose at 200 °C and 1 MPa H〈sub〉2〈/sub〉 for 3 h. When starch was converted over Cu-Pd/US, 2,5-DMF was formed with 53.6% yield. Direct cellulose conversion into 2,5-DMF with a yield of 29.8% was achieved in the presence of 0.01 M HCl and Cu-Pd/US. The presence of the amino functional group (-NH〈sub〉2〈/sub〉) in the UiO-66 framework was beneficial for improving the feed conversion and maintaining catalyst recyclability up to five times with almost no activity loss.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309925-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Shuai Wang, Ping He, Lingpu Jia, Mingqian He, Tinghong Zhang, Faqin Dong, Mingzhang Liu, Huanhuan Liu, Ying Zhang, Caixia Li, Jun Gao, Liang Bian〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Oxygen evolution reaction is a significant half-reaction for water splitting, while its sluggish kinetics and high-cost catalyst hinder the commercial application. In this work, we report a novel nanocoral-like NiSe〈sub〉2〈/sub〉/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 composite as highly efficient catalyst for water oxidation in 1.0 M KOH solution. Based on the support of multi-layered g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉, NiSe〈sub〉2〈/sub〉/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 composite exhibits favorable electrocatalytic performances with low overpotential of 290 mV at current density of 40 mA cm〈sup〉−2〈/sup〉 and low onset potential of 1.38 V (vs. RHE). In addition, NiSe〈sub〉2〈/sub〉/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 composite delivers higher current density (199 mA cm〈sup〉−2〈/sup〉) than those of pure NiSe〈sub〉2〈/sub〉 (142 mA cm〈sup〉−2〈/sup〉) and multi-layered g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 (112 mA cm〈sup〉−2〈/sup〉) at potential of 2.0 V (vs. RHE). Furthermore, NiSe〈sub〉2〈/sub〉/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 composite exhibits an excellent long-term electrochemical stability for 10 h. The outstanding electrocatalytic properties above suggest that NiSe〈sub〉2〈/sub〉/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 composite is a candidate for the substitution of noble metal based catalyst for oxygen evolution reaction.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Shown up are the polarization curves of as-prepared catalysts in 1.0M KOH solution at a scan rate of 1 mV s〈sup〉−1〈/sup〉 for electrocatalytic oxygen evolution reaction. The inset shows the morphology of as-prepared NiSe〈sub〉2〈/sub〉/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 composite.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318310427-ga1.jpg" width="264" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Jong Bin Lim, Seung Hyeok Cha, Suk Bong Hong〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Four cage-based, small-pore zeolites with similar framework Fe contents (0.7-0.9 wt%) but different framework structures (i.e., Fe-PST-7, Fe-LTA, Fe-SSZ-13, and Fe-RTH) have been synthesized and employed as direct N〈sub〉2〈/sub〉O decomposition catalysts. When steam-activated, the light-off temperatures (770 K) for Fe-PST-7 and Fe-LTA were found to be about 40 K lower under wet feed conditions than that (810 K) for Fe-ZSM-5, the most widely studied catalyst for this reaction. Furthermore, their light-off temperatures were found to be even lower than the temperature (780 K) for Fe-FER, the best direct N〈sub〉2〈/sub〉O decomposition catalyst. The overall characterization results of our study strongly suggest that the presence of strong Brønsted acid sites in zeolites, as well as the zeolite framework topology, has a profound effect on the type and distribution of extraframework Fe species, and therefore the N〈sub〉2〈/sub〉O decomposition activity of supported Fe catalysts.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318310397-ga1.jpg" width="356" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Z. Buniazet, A. Cabiac, S. Maury, D. Bianchi, S. Loridant〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Ferrierite was shown to be highly efficient in the conversion of isobutanol to butenes with selectivity values higher than 98%. Furthermore, its isomerisation activity is remarkable since proportion of linear butenes higher than 80% was obtained in the present study confirming patents claims. This selectivity was shown to increase with temperature and contact time as well as with time on stream.〈/p〉 〈p〉Neither water added to the feed nor water generated by dehydration has an impact on the structure of ferrierite as shown by XRD and 〈sup〉27〈/sup〉Al NMR. A slight enhancement of catalytic activity was observed below 250 °C and could be due to an increase in the number of BAS as suggested by 〈em〉in situ〈/em〉 acidity measurements achieved at the reaction temperatures in presence of water vapor while competition of adsorption would inhibit the catalytic activity above 250 °C. Furthermore, water was shown to improve dramatically selectivity to linear butenes at low conversion. We propose that water inhibits the proton shift of isobutylcarbenium ions or deprotonation sites leading to isobutene but not acid sites able to isomerize isobutylcarbenium ions into linear carbocations leading to linear butenes. At high conversions, both coke formation and water generated by dehydration could improve selectivity to linear butenes by neutralization of unselective sites responsible for proton-shift reaction.〈/p〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318310579-ga1.jpg" width="313" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Dongni Liu, Dongyun Chen, Najun Li, Qingfeng Xu, Hua Li, Jinghui He, Jianmei Lu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The application of three-dimensional (3D) aerogels for immobilizing powder catalysts can greatly enhance the catalyst cycling stability. In this study, we modify two-dimensional (2D) graphitic carbon nitride (g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉) nanosheets with zero-dimensional (0D) silver metavanadate (AgVO〈sub〉3〈/sub〉) quantum dots. The resulting 0D-2D heterojunction facilitates the separation of electron-hole pairs, and exhibits high efficiency for removing nitric oxide (NO) at low concentrations (600 ppb) at room temperature. The removal efficiency is much higher than that of pure g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉. The porous network framework of the 3D AgVO〈sub〉3〈/sub〉-g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉-graphene hybrid aerogel is formed by bridging of graphene oxide sheets. This results in the heterojunction further enhancing electron-hole separation. The modification of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 promotes the separation of photogenerated carriers in a step by step manner, and enhances their oxidation-reduction ability. The AgVO〈sub〉3〈/sub〉-g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉-graphene hybrid aerogel exhibits excellent catalytic activity for NO removal (maximum of 65%). Cycling experiments verify the stability and recyclability of the aerogel.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉3D AgVO〈sub〉3〈/sub〉-g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉-Graphene hybrid aerogel was synthesized for high efficiency removal of low concentration (600 ppb) of nitric oxide at room temperature under visible light.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318310622-ga1.jpg" width="277" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Zongkui Kou, Lei Zhang, Yuanyuan Ma, Ximeng Liu, Wenjie Zang, Jian Zhang, Shaozhuan Huang, Yonghua Du, Anthony K. Cheetham, John Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein, we have developed a facile process of synthesizing N and O surface-terminated 2D molybdenum carbide nanomeshes (Mo〈sub〉2〈/sub〉CT〈sub〉x〈/sub〉 NMs) and assembling them into 3D microflowers (Mo〈sub〉2〈/sub〉CT〈sub〉x〈/sub〉 MFs) by one-step pyrolysis of Mo/Zn bimetallic imidazolate frameworks. When used as an oxygen evolution reaction (OER) catalyst, the Mo〈sub〉2〈/sub〉CT〈sub〉x〈/sub〉 NMs thus derived exhibit outstanding catalytic activity with an overpotential of 180 mV at the current density of 10 mA cm〈sup〉−2〈/sup〉. This enables Mo〈sub〉2〈/sub〉CT〈sub〉x〈/sub〉 NMs to become one of the best OER electrocatalysts ever reported, with the desired stability in alkaline environment which is a major challenge for most of the non-oxide/hydroxide based electrocatalyts. Additionally, the Mo〈sub〉2〈/sub〉CT〈sub〉x〈/sub〉 MFs can catalyze the hydrogen evolution reaction (HER) and act as bifunctional electrocatalysts for overall water splitting which can attain a current density of 10 mA cm〈sup〉−2〈/sup〉 at 1.7 V. Mo LIII-edge X-ray near-edge absorption studies combined with theoretical calculations imply that surface-terminated oxygen is crucial in activating the outstanding OER performance, whereas the top Mo atomic sites on the surface contribute to excellent HER performance.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318310580-ga1.jpg" width="469" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): A. Truppi, F. Petronella, T. Placido, V. Margiotta, G. Lasorella, L. Giotta, C. Giannini, T. Sibillano, S. Murgolo, G. Mascolo, A. Agostiano, M.L. Curri, R. Comparelli〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Semiconductor/metal nanocomposites based on anatase TiO〈sub〉2〈/sub〉 nanoparticles and Au nanorods (TiO〈sub〉2〈/sub〉/AuNRs) were prepared by means of a co-precipitation method and subsequently calcinated at increasing temperature (from 250° to 650 °C) obtaining up to 20 g of catalysts. The structure and the morphology of the obtained nanocomposite material were comprehensively characterized by means of electron microscopy (SEM and TEM) and X-ray diffraction techniques. The photocatalytic performance of the TiO〈sub〉2〈/sub〉/AuNRs nanocomposites was investigated as a function of the calcination temperature in experiment of degradation of water pollutants under both UV and UV–vis irradiation, Photocatalytic experiments under UV irradiation were performed by monitoring spectrophotometrically the decolouration of a target compound (methylene blue, MB) in aqueous solution. UV–vis light irradiation was, instead, used for testing the photocatalytic removal of an antibiotic molecule, Nalidixic acid, by monitoring the degradation process by HPLC-MS analysis. Interestingly, TiO〈sub〉2〈/sub〉/AuNRs calcined at 450 °C was up to 2.5 and 3.2 times faster than TiO〈sub〉2〈/sub〉P25 Evonik, that is a commercially available reference material, in the photocatalytic degradation of the Methylene Blue and the Nalidixic Acid, under UV and visible light, respectively. The same nanocomposite material showed a photocatalytic degradation rate for the two target compounds up to 13 times faster than the bare TiO〈sub〉2〈/sub〉-based catalysts.〈/p〉 〈p〉The obtained results are explained on the basis of the structure and morphology of the nanocomposites, that could be tuned according to the preparative conditions. The role played by the plasmonic domain in the heterostructured materials, either under UV and UV–vis illumination, is also highlighted and discussed.〈/p〉 〈p〉The overall results indicate that the high photoactivity of TiO〈sub〉2〈/sub〉/AuNRs in the visible range can be profitably exploited in photocatalytic applications, thanks also to the scalability of the proposed synthetic route, thus ultimately envisaging potential innovative solution for environmental remediation.〈/p〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092633731831052X-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Xifeng Ding, Zhipeng Gao, Dong Ding, Xinyu Zhao, Huaiyu Hou, Shihua Zhang, Guoliang Yuan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cation deficiency in perovskite oxides can alter the crystal structure, oxygen stoichiometry and other physiochemical properties, substantially promote the electro-catalytic activity for oxygen reduction reaction (ORR) at elevated temperatures. In this work, a small strontium deficiency was introduced into SrCo〈sub〉0.8〈/sub〉Nb〈sub〉0.1〈/sub〉Ta〈sub〉0.1〈/sub〉O〈sub〉3-〈/sub〉〈em〉δ〈/em〉 (S100CNT) to promote the electrochemical activity of ORR. Cation deficient Sr〈sub〉0.95〈/sub〉Co〈sub〉0.8〈/sub〉Nb〈sub〉0.1〈/sub〉Ta〈sub〉0.1〈/sub〉O〈sub〉3-〈/sub〉〈em〉δ〈/em〉 (S095CNT) displayed higher oxygen vacancy concentration than that of stoichiometric S100CNT. The decreased average bonding energy (ABE) and the increased critical radius (〈em〉r〈sub〉c〈/sub〉〈/em〉) of S095CNT could be responsible for the decreased activation energy for oxygen ions transfer. Consequently, the ORR activity of S095CNT cathode was significantly improved. The S095CNT cathode shows an area specific resistance of 0.07 Ω cm〈sup〉2〈/sup〉 at 650 °C, which was only about 63% of S100CNT. Moreover, S095CNT displayed much higher CO〈sub〉2〈/sub〉 tolerance than the state-of-the-art Ba〈sub〉0.5〈/sub〉Sr〈sub〉0.5〈/sub〉Co〈sub〉0.8〈/sub〉Fe〈sub〉0.2〈/sub〉O〈sub〉3〈/sub〉-〈em〉δ〈/em〉 (BSCF) cathode for SOFC. Thus, the fast ORR and high stability makes S095CNT promising material for devices involving oxygen electrochemistry such as solid oxide fuel cells, electrolysis cells, or gas separation membranes.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318310464-ga1.jpg" width="287" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Truong-Giang Vo, Yian Tai, Chia-Ying Chiang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Severe surface charge recombination is known as a major energy loss that hinders the performance and durability of solar water splitting. Here, a facile process is developed for preparing a new type of low-cost ferrite phosphate as an efficient co-catalyst to suppress charge recombination and stabilize bismuth vanadate (BiVO〈sub〉4〈/sub〉) photoelectrodes. The composite photoanode exhibits a high photocurrent density of 2.28 mAcm〈sup〉−2〈/sup〉, which corresponds to a 250% increase compared to that of pristine BiVO〈sub〉4〈/sub〉. Deposition of cocatalyst has yielded a large cathodic shift (∼500 mV) in the onset potential, high hole oxidation efficiency of about 90%. The Fe-Pi/ BiVO〈sub〉4〈/sub〉 photoanode demonstrates an impressive performance of photostability and attains a stable photocurrent density for more than 2 h at 1.23 V〈sub〉RHE〈/sub〉 without declining. Comprehensive photoelectrochemical studies suggest that ferrite phosphate could boost the photoelectrochemical properties of the BiVO〈sub〉4〈/sub〉 underlayer by mediating hole extraction across the photoexcited semiconductor-electrolyte interface. This in turn enhances photoconversion efficiency and prevents the photooxidation of the photoanode, ensuring prolonged stability. The results provide deeper understanding of the role of cocatalyst nanostructures decorated with semiconductors in solar water splitting.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉A three-dimensional branched array based on ferrite phosphate/bismuth vanadate has been was fabricated for photoelectrochemical water splitting. Such a unique architecture not only offer fast charge transport but also higher surface, thus in turn boosted the photoelectrocatalytic activity and photoanode stability.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318310518-ga1.jpg" width="369" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Thibault Rafaïdeen, Stève Baranton, Christophe Coutanceau〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The effect of the composition of carbon supported PdAu nanomaterials toward electrocatalytic oxidation of glucose and xylose was evaluated in alkaline medium. Pd〈sub〉x〈/sub〉Au〈sub〉10-x〈/sub〉/C catalysts were synthesized by a water-in-oil microemulsion method and characterized by physical (TGA, AAS, TEM, XRD) and electrochemical methods. Bulk Pd/Au alloys were formed, but the surface composition was different than the bulk one. The surface of Pd〈sub〉x〈/sub〉Au〈sub〉10-x〈/sub〉/C catalysts as determined by electrochemical method were enriched in Pd with respect to the nanoparticle bulk composition as determined by atomic absorption spectroscopy (AAS). Electrochemical experiments combined with in situ infrared spectroscopy measurements showed the dissociative adsorption of aldoses on Pd-rich catalysts at low potentials (appearance of the typical band of CO〈sub〉ads〈/sub〉 on Pd surface). For catalysts with Au at. % ≥70%, this band was not visible. Pd〈sub〉3〈/sub〉Au〈sub〉7〈/sub〉/C catalyst provided the lowest oxidation onset potential, the highest activity and the best selectivity towards gluconate and xylonate. Therefore, long term chronoamperometry measurements of glucose and xylose electrooxidation were performed on this catalyst in a 25 cm〈sup〉2〈/sup〉 geometric active surface area electrolysis cell at a voltage of 0.4 V and at 293 K. Reaction products were analyzed by HPLC every hour, and by 〈sup〉1〈/sup〉H NMR at the end of the experiments. The main products were gluconate and xylonate. Glucose oxidation led to selectivity in gluconate of 87% for 67% conversion, and higher for lower conversion. Xylose oxidation led to selectivity in xylonate of 100% after 1 and 2 h electrolysis and of 92% after 6 h (52% conversion). The conversion of glucose and xylose into gluconate and xylonate was performed with high selectivity and an energy cost below 36 € per ton of reaction products.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318310567-ga1.jpg" width="355" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Mengfang Liang, Timur Borjigin, Yuhao Zhang, Beihong Liu, Hui Liu, Hong Guo〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hollow heterostructured g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉@CeO〈sub〉2〈/sub〉 photocatalysts with rich oxygen vacancies are controllable designed by a facile strategy. The synergetic effect and oxygen vacancies of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉@CeO〈sub〉2〈/sub〉 play the major role in the process of CO〈sub〉2〈/sub〉 reduction, leading to CH〈sub〉4〈/sub〉 generating much earlier and higher concentration than that of the pristine g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 and CeO〈sub〉2〈/sub〉 alone. Meanwhile, the unique hollow structures can make multiple reflections of light in the cavity, and thus enhance the utilization efficiency of light. Moreover, the L-cysteine offers amine groups and meanwhile is anchored on the surface of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 during the synthesis process, and thus contributes greatly to the enhanced CO〈sub〉2〈/sub〉 adsorption capability. Additionally, the large CO〈sub〉2〈/sub〉 adsorption capability is also beneficial for the enhanced photocatalytic activity. Therefore, the novel photocatalysts exhibit a remarkable reduction performance for CO〈sub〉2〈/sub〉 reduction under visible light irradiation. The g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉@CeO〈sub〉2〈/sub〉 (CeO〈sub〉2〈/sub〉 49.7 wt %) shows the highest yields of CH〈sub〉4〈/sub〉 (3.5 μmol g〈sup〉−1〈/sup〉), CH〈sub〉3〈/sub〉OH (5.2 μmol g〈sup〉−1〈/sup〉) and CO (16.8 μmol g〈sup〉−1〈/sup〉), which are higher than most of other latest reported g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 based photocatalysts for CO〈sub〉2〈/sub〉 photoreduction, including coupled with semiconductors and noble metal cocatalysts. This strategy might represent a novel way for the effective conversion of CO〈sub〉2〈/sub〉 to clean fuels and can also be great potential used in the energy and environmental science.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318310609-ga1.jpg" width="253" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Carmine Lops, Andrea Ancona, Katia Di Cesare, Bianca Dumontel, Nadia Garino, Giancarlo Canavese, Simelys Hérnandez, Valentina Cauda〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, it is proposed an environmental friendly sonophotocatalytic approach to efficiently treat polluted waters from industrial dyes exploiting ZnO micro- and nano-materials. For the first time, we deeply investigated the generation of reactive oxygen species (ROS) under ultrasound stimulation of different ZnO structures by Electron Paramagnetic Resonance Spectroscopy (EPR). Indeed, five zinc oxide (ZnO) micro- and nano-structures, 〈em〉i.e.〈/em〉 Desert Roses (DRs), Multipods (MPs), Microwires (MWs), Nanoparticles (NPs) and Nanowires (NWs), were studied for the Rhodamine B (RhB) sonodegradation under ultrasonic irradiation. The DRs microparticles demonstrated the best sonocatalytic performance (100% degradation of RhB in 180 min) and the highest OH〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉 radicals generation under ultrasonic irradiation. Strikingly, the coupling of ultrasound and sun-light irradiation in a sonophotodegradation approach led to 100% degradation efficiency, 〈em〉i.e.〈/em〉 color reduction, of RhB in just 10 min, revealing a great positive synergy between the photocatalytic and sonocatalytic mechanisms. The RhB sonophotocatalytic degradation was also evaluated at different initial dye concentrations and with the presence of anions in solution. It was demonstrated a good stability over repeated cycles of dye treatment, which probe the applicability of this technique with industrial effluents. In conclusion, sonophotocatalytic degradation synergizing sunlight and ultrasound in the presence of DRs microparticles shows a great potential and a starting point to investigate further the efficient treatment of organic dyes in wastewater.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092633731831049X-ga1.jpg" width="218" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Junwei Fu, Quanlong Xu, Jingxiang Low, Chuanjia Jiang, Jiaguo Yu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The appropriate interfacial contact of heterojunction photocatalysts plays a critical role in transfer/separation of interfacial charge carriers. Design of two-dimensional (2D)/2D surface-to-surface heterojunction is an effective method for improving photocatalytic activity since greater contact area can enhance interfacial charge transfer rate. Herein, ultrathin 2D/2D WO〈sub〉3〈/sub〉/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 step-like composite heterojunction photocatalysts were fabricated by electrostatic self-assembly of ultrathin tungsten trioxide (WO〈sub〉3〈/sub〉) and graphitic carbon nitride (g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉) nanosheets. The ultrathin WO〈sub〉3〈/sub〉 and g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 nanosheets were obtained by electrostatic-assisted ultrasonic exfoliation of bulk WO〈sub〉3〈/sub〉 and a two-step thermal-etching of bulk g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉, respectively. The thickness of ultrathin WO〈sub〉3〈/sub〉 and g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 nanosheets are 2.5–3.5 nm, which is equivalent to 5–8 atomic or molecular layer thickness. This ultrathin layered heterojunction structure can enhance surface photocatalytic rate because photogenerated electrons and holes at heterogeneous interface more easily transfer to surface of photocatalysts. Therefore, the obtained ultrathin 2D/2D WO〈sub〉3〈/sub〉/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 step-scheme (S-scheme) heterojunction photocatalysts exhibited better H〈sub〉2〈/sub〉-production activity than pure g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 and WO〈sub〉3〈/sub〉 with the same loading amount of Pt as cocatalyst. The mechanism and driving force of charge transfer and separation in S-scheme heterojunction photocatalysts are investigated and discussed. This investigation will provide new insight about designing and constructing novel S-scheme heterojunction photocatalysts.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318310610-ga1.jpg" width="242" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Jie Xiong, Jing Li, Jiawei Shi, Xinlei Zhang, Weiwei Cai, Zehui Yang, Hansong Cheng〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Phosphorus contained metallic 1T-MoS〈sub〉2〈/sub〉 produced from 〈em〉in-situ〈/em〉 ammonium intercalation induced surface sulfur atom distortion of MoS〈sub〉2〈/sub〉 rooted in N,P,S-codoped hierarchical flowerlike carbon (HCMF) hybrids were successfully prepared 〈em〉via〈/em〉 a dopamine self-polymerization together with molybdate process followed by a hydrothermal reduction route. On account of the coupling effect of metallic phase, defect-rich character, heteroatomic dopants and highly conductive carbon support, the P-MoS〈sub〉2〈/sub〉@HCMF demonstrates prominent performances with an overpotential of merely 86 mV to deliver a current density of 10 mA cm〈sup〉–2〈/sup〉 and a small Tafel slope of 42.35 mV dec〈sup〉–1〈/sup〉 for hydrogen evolution reaction (HER) in 0.5 M H〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉, which are among the best results for molybdenum disulfide based HER catalysts. Strikingly, benefiting from S vacancies and P dopant functioning as electron donors, as well as strain arisen from the tensile of rigid carbon microflower scaffold to MoS〈sub〉2〈/sub〉 nanosheets to overcome agglomeration barriers of nanosheets, P-MoS〈sub〉2〈/sub〉@HCMF remained well the pristine 1 T phase and exhibited superior cycling stability with indistinguishable overpotential decay over 5000 sweeps and extraordinary HER durability during the 100 h long-term operation with negligible current deterioration. These findings highlight the prospective potential of P-MoS〈sub〉2〈/sub〉@HCMF as a highly efficient and stable noble metal-free electrocatalyst towards HER.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318310543-ga1.jpg" width="442" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Amal Abdelhaleem, Wei Chu, Xiaoliang Liang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Degradation of diphenamid (DPA) was examined by a novel process through sulfite activation by Fe impregnated N-doped TiO〈sub〉2〈/sub〉 (FeN-TiO〈sub〉2〈/sub〉) under visible LED (Vis LED). The FeN-TiO〈sub〉2〈/sub〉 was synthesized using an impregnation method and characterized by various techniques. The mechanism of sulfite activation by FeN-TiO〈sub〉2〈/sub〉 under Vis LED was proposed. The reaction mechanisms were further elucidated by investigating the XPS spectra of the catalysts before and after the reaction. Thirty intermediates were identified and twenty-four of them are newly reported. A new pathway was reported for the first time in the DPA studies through the rupture of benzene ring linkage. A higher mineralization degree was achieved using the FeN-TiO〈sub〉2〈/sub〉/sulfite/Vis LED process, which is not in accordance with previous reports on sulfite-based processes. The absence of sulfate adducts could provide a rational explanation of the higher mineralization degree during DPA degradation. Based on reusability test, the DPA degradation efficiency increased after successive usage of the catalyst. After the complete degradation of DPA, the leached Fe-ions were found to be negligible and sulfite was completely depleted. Considering several factors such as the cheap source of sulfite (an air pollutant waste from flue-gas desulfurization process), low cost of Fe, negligible leaching of Fe-ions, and high energy efficiency of Vis LED light, the FeN-TiO〈sub〉2〈/sub〉/sulfite/Vis LED process could be a practical and green technology for the removal of wastewater contaminants.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311433-ga1.jpg" width="360" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Wenxin Zhu, Tianshu Zhang, Yi Zhang, Zhihao Yue, Yinge Li, Rong Wang, Yanwei Ji, Xuping Sun, Jianlong Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Although NiFe-based (oxy)hydroxides have been recognized as the most promising anode materials for industrial water splitting, the existed synthetic methods are difficult to fabricate NiFe-based (oxy)hydroxides simultaneously fulfilling the requirements of low-cost and ambient synthetic process, high performance, and easier realization of large-scale production. In this work, a simple while effective strategy was proposed to fabricate well-aligned Ni-Fe hydroxide nanosheets array on Ni foam (NiFe-OH NS/NF) by the ambient spontaneous redox reaction between Ni foam and Fe〈sup〉3+〈/sup〉and accompanied hydrolysis co-deposition of the generated Ni〈sup〉2+〈/sup〉, Fe〈sup〉2+〈/sup〉/Fe〈sup〉3+〈/sup〉, and OH〈sup〉−〈/sup〉. The tailored highly-oriented amorphous and nanoporous nanosheets structure as well as the strong electronic interaction between Ni and Fe species endow this NiFe-OH NS/NF with excellent OER activity that a large current density of 500 mA cm〈sup〉−2〈/sup〉 could be well afforded at a low overpotential of 292 mV. Importantly, the manufacturing and raw-materials cost to synthesize the NiFe-OH NS/NF by this strategy is estimated to be just $0.0165 per cm〈sup〉2〈/sup〉, much lower than those for other reported self-supported Fe-containing catalyst materials. Also, this ambient means not only could be applicable to the large-scale production of size-tunable NiFe-OH NS/NF with stable nanoarray structure, but also could be easily used for the synthesis of NiCo NS/NF and NiCoFe NS/NF for applications.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉A facile ambient redox and hydrolysis co-precipitation strategy enables ultralow-cost and large-scale production of well-aligned nickel-iron hydroxide nanosheets array on Ni foam toward practical-oriented high-performance water oxidation.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311743-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Sharifeh Rezaee, Saeed Shahrokhian〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Porous carbon template decorated with mixed transition metals/metal oxides with tunable architecture is becoming increasingly important and attractive as a kind of novel electrode materials. In this way, mixed-metallic metal-organic frameworks (MOFs) provide an opportunity for fabrication of homogeneous mixed metals/metal oxides distribution in the porous carbon frame without any carbon precursor additive. Also, structures, dimensions and electrochemical performance of MOFs can be readily manipulated by simply tuning the metals molar ratio. In this study, we demonstrate the design and fabrication of petal-like NiCo/NiO-CoO metal/metal oxides with a rational composition embedded in 3D ultrathin nanoporous carbon composite)NiCo/NiO-CoO/NPCC(. This nanocomposite is synthesized by a two-steps procedure involving preparation of bimetallic MOFs by partially substituting Ni〈sup〉2+〈/sup〉 in the Ni-MOF structure with Co〈sup〉2+〈/sup〉 (Ni-Co/BDC [BDC = 1,4-Benzene dicarboxylic acid]) and direct carbonization process in the N〈sub〉2〈/sub〉 atmosphere at 900 °C. The prepared nanocomposite was used directly as a non-precious electrocatalyst for methanol oxidation reaction. The results indicated that, in comparison to the monometallic metal/metal oxides distributed in nanoporous carbon composite (Ni/NiO/NPCC and Co/CoO/NPCC), the mixed metals/metal oxides NiCo/NiO-CoO/NPCC exhibits excellent electrochemical performance toward the anodic oxidation of methanol. The unique ultrathin porous petal-like structure with free pores and the enlarged specific surface area provides fast ion/electron transfer, leading to faster kinetics, lower over-potential, and higher electro-catalytic reactivity. Besides their intriguing structural features, the excellent conductivity of carbon frame, as well as a rational composition of two constituents and synergistic effects from cobalt, nickel and their oxides provides favorable catalytic activity for the electro-oxidation of methanol. Therefore, it is believed that this novel multi-component composites demonstrates good electrocatalytic activity and suitable stability towards the methanol oxidation.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311664-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Yue Sun, Yunjie Zhou, Cheng Zhu, Wenjing Tu, Huibo Wang, Hui Huang, Yang Liu, Mingwang Shao, Jun Zhong, Shuit-Tong Lee, Zhenhui Kang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Active and inexpensive electrocatalysts for methanol oxidation reaction (MOR) are highly required for the practical application of direct methanol fuel cells (DMFCs). However, efficient MOR is limited by using the expensive and rare noble metal-based catalysts. Here we report a Cu@CoO〈sub〉x〈/sub〉 core-cage nanostructure on carbon layers (CLs) for superior electrocatalysis of MOR in the alkaline media, which shows an excellent specific activity of 150.41 mA cm〈sup〉−2〈/sup〉 and a high mass activity of 467.94 mA mg〈sup〉-1〈/sup〉 at the potential of 0.8 V vs. SCE (1.85 V vs. RHE) in 1 M KOH + 1 M CH〈sub〉3〈/sub〉OH. It represents the highest MOR activity ever reported for noble metal-free catalysts. Synchrotron radiation based 〈em〉in-situ〈/em〉 X-ray absorption spectroscopy reveals that the outside CoO〈sub〉x〈/sub〉 cage can form a high Co〈sup〉4+〈/sup〉 state to easily oxidize methanol, while the adsorption experiments indicate that Cu can act as the methanol adsorption center. The capture-catalysis process on the core-cage structure thus leads to the excellent MOR activity. The CLs can also anchor the Cu@CoO〈sub〉x〈/sub〉 particles and accelerate the charge transport to enhance the performance. The Cu@CoO〈sub〉x〈/sub〉-CLs catalyst is economical, abundant, highly active and stable, which has the potential to act as a good alternate material for noble metal-based catalysts in DMFCs.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉A Cu@CoO〈sub〉x〈/sub〉 core-cage structure on carbon layers shows an excellent catalytic activity and outstanding durability for methanol oxidation.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311706-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Yuxiang Zhu, Tao Wan, Xiaoming Wen, Dewei Chu, Yijiao Jiang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This work reports tunable heterojunction architectures of cobalt oxides (CoO〈sub〉x〈/sub〉) nanoparticles confined on well-arrayed graphitic carbon nitride nanotubes (C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 NTs) by using a facile one-pot method but under different annealing atmospheres. A Type II heterojunction of cobalt monoxide nanoparticles (CoO NPs)/C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 NTs was obtained after annealing under vacuum, and fine CoO NPs less than 8 nm in size were homogeneously anchored on the surface of C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 NTs. A Type I heterojunction of tricobalt tetraoxide (Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉)/C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 NTs were formed under air condition, and Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 NPs in the size range of 20 to 80 nm were aggregated on the surface. The photocatalytic activities of these two heterojunctions were evaluated with hydrogen production from water splitting. The strategically developed CoO/C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 NTs with a 7 wt. % CoO shows the highest H〈sub〉2〈/sub〉 yield under visible light irradiation and the best stability among the photocatalysts studied in this work. Comprehensive characterization results reveal that the superior performance of CoO/C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 NTs may be attributed to the uniformly distributed smaller nanoparticles on the well-arrayed nanotubes, the longer lifetime of excited electrons, the faster charge transfer and the stronger electronic interaction between the heterojunctions. Our Kelvin probe force microscopy results firmly verify that the CoO/C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 NT and Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉/C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 NT nanocomposites form a Type II and Type I heterojunction, respectively, and charge transfer pathways and reaction mechanisms are therefore established.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311688-ga1.jpg" width="376" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Juliana Pérez-Obando, Diego A. Marín-Silva, Adriana N. Pinotti, Luis R. Pizzio, Paula Osorio-Vargas, Julián A. Rengifo-Herrera〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Urea modified TiO〈sub〉2〈/sub〉 nanoparticles were synthesized at different TiO〈sub〉2〈/sub〉: urea ratios (10, 30 and 60 (%wt) named UTiO〈sub〉2〈/sub〉-10, 30 and 60) by sol-gel method and annealing at 400 °C during 1 h. Characterization revealed the presence of TiO〈sub〉2〈/sub〉 nanoparticles with visible light absorption (between 400 and 500 nm) probably due by the formation of thermolysis urea byproducts such as melon, which may induce a TiO〈sub〉2〈/sub〉/melon heterojunction. Then, modified nanoparticles were immobilized on chitosan films by adding 30% (70QS/30UTiO〈sub〉2〈/sub〉) and 50% 50QS/50UTiO〈sub〉2〈/sub〉) of UTiO〈sub〉2〈/sub〉 nanoparticles. Functionalized films were characterized by SEM-EDS, DRS and AFM. Photo-induced degradation of malachite green stains was evaluated on these films under different wavelengths. Upon UV-A + visible light irradiation, films showed good activity even slightly better than those containing Evonik P-25 (70QS/30P-25). Upon visible light between 450 and 800 nm, films evidenced a satisfactory performance but slower than under UV-A + visible light irradiation whereas the photobleaching activity of 70QS/30P-25 was very poor. When visible light irradiation with wavelengths higher than 590 nm was used, a slight photobleaching was also observed. DRS spectra taken at different irradiation times showed that dye underwent N-demethylated oxidative reactions either upon UV–vis or visible light irradiation. ATR-FTIR measurements revealed the generation of benzophenones after 6 h of irradiation probably suggesting the formation of singlet oxygen under visible light. 70QS/30UTiO〈sub〉2〈/sub〉-10 films showed a good photo-bleaching activity after 18 h of continuous UV-A + visible light irradiation.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311573-ga1.jpg" width="207" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Lei Lu, Zhenyu Xin, Xiaohui Wang, Shaomang Wang, Heng Zhu, Taozhu Li, Yaliu Gu, Shicheng Yan, Zhigang Zou〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Efficiency of solar-driven CO〈sub〉2〈/sub〉 into fuels is largely limited by the sluggish reaction kinetics resulting from high activation barriers and poor electron-hole separation. Here, a synergistic strategy was proposed to overcome these obstacles. As a prototype, KOH-modified Ni/LaTiO〈sub〉2〈/sub〉N photocatalyst afforded a high performance in CO〈sub〉2〈/sub〉 reduction with a generation rate of 9.69 μmol g〈sup〉−1〈/sup〉 for CH〈sub〉4〈/sub〉 and 0.31 μmol g〈sup〉−1〈/sup〉 for CO, about 5 times higher than the catalytic activities of LaTiO〈sub〉2〈/sub〉N. The prominent enhancement results in the following effects: (1) Schottky barrier at Ni/LaTiO〈sub〉2〈/sub〉N interface boosts separation of electron-hole pairs. (2) The OH- of KOH as basic sites favors activation of CO〈sub〉2〈/sub〉 into CO〈sub〉3〈/sub〉〈sup〉2-〈/sup〉 species, significantly improving the reaction kinetics of CO〈sub〉2〈/sub〉 reduction. (3) The OH- also functions as hole acceptor, boosting the proton release from H〈sub〉2〈/sub〉O oxidation.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092633731831155X-ga1.jpg" width="271" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Yang Lu, Zi Wei, Nilesh P. Salke, Lu Yu, Hao Yan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Si-doping is an effective approach to enhance the electron transport and the photocatalytic activity of photocatalyst. In this study, for the first time the silicate glass such as fluorine-doped tin oxide (FTO) glass substrate is used as the silicon source for preparing Si-doped TiO〈sub〉2〈/sub〉 photoanodes. First, the rutile TiO〈sub〉2〈/sub〉 nanowires (NWs) were grown on FTO glass substrates by hydrothermal reaction, accompanying with the gradual dissolution of glass to generate soluble Si dopant incorporated into TiO〈sub〉2〈/sub〉 NWs. Second, the TiO〈sub〉2〈/sub〉 NWs were reduced to form the Ti〈sup〉3+〈/sup〉 by H〈sub〉2〈/sub〉S reduction. Finally, the Si-doped TiO〈sub〉2〈/sub〉 photoanodes with higher doping density was obtained by calcination. The visible photocatalytic activity of Si-doped TiO〈sub〉2〈/sub〉 NWs photoanode towards water splitting increased about three times as compared with pure TiO〈sub〉2〈/sub〉 NWs. Reduction by H〈sub〉2〈/sub〉S resulted in the enhanced electron transport and massive increase in charge-carrier density. This work provides a novel paradigm for silicon doping in materials for accelerating their carrier transport and applications.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Si self-doped TiO〈sub〉2〈/sub〉 nanowires photoanode is prepared by a hydrothermal method and H〈sub〉2〈/sub〉S treatment using glass as dopant source for the first time. The photocatalyst exhibits three times photoactivity of pure TiO〈sub〉2〈/sub〉, which is mainly attributed to the enhanced electron transport.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311561-ga1.jpg" width="243" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): S. Navarro-Jaén, F. Romero-Sarria, M.A. Centeno, O.H. Laguna, J.A. Odriozola〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The importance of water availability during the WGS reaction has been extensively reported. Thus, the search of new supports able to interact with the water molecule is of great importance. In this work, a series of phosphate-type supports containing Ce, Ca and Ti have been studied, demonstrating that water interaction with the support is closely related to the textural properties, surface composition and crystal structure of the solids. Additionally, DRIFTS results showed that different interaction mechanisms with the water molecule occur depending on the support. The system containing Ca dissociates the water molecule and interacts with it via the phosphate and Ca〈sup〉2+〈/sup〉 ions. However, the Ce systems retain water in its molecular form, which interacts with the solids via hydrogen bonding with the phosphate groups. On the other hand, the Ti system experiences a loss of phosphorous, presenting a low degree of interaction with the water molecule. Additionally, the behavior of the supports with water has been successfully related to the WGS catalytic activity of the corresponding phosphate-supported Pt catalysts.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311755-ga1.jpg" width="371" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Jae-Sung Bae, Seok Yong Hong, Ji Chan Park, Geun Bae Rhim, Min Hye Youn, Heondo Jeong, Shin Wook Kang, Jung-Il Yang, Heon Jung, Dong Hyun Chun〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The iron-ore-based catalysts (IO-CAT) with catalytic properties similar to those of conventional precipitated iron-based catalysts (PFe-CAT) were successfully prepared through a combination of a wet-milling process and a wet impregnation method. This approach was much more economical and eco-friendly than a conventional precipitation technique in terms of the amounts of water and chemicals used and discharged. The IO-CAT exhibited higher surface area, a larger pore volume, and a smaller crystallite size than the unmodified iron ore samples (IO-U). In particular, the pore volume of IO-CAT was as large as that of PFe-CAT. Furthermore, the reducibility and surface basicity of IO-CAT were much higher than those of IO-U and comparable to those of PFe-CAT, which implies that a reduction promoter, Cu, and an alkali promoter, K, are used successfully to impregnate the well-developed pore structure of IO-CAT. As a result, the IO-CAT showed catalytic performance favorable for low-temperature Fischer-Tropsch synthesis (LT-FTS) using hydrogen-deficient syngas (H〈sub〉2〈/sub〉/CO = 1) in all aspects of CO conversion (75%), CO〈sub〉2〈/sub〉 selectivity (43 C-mol%), and C〈sub〉5+〈/sub〉 selectivity in hydrocarbons (71 wt%). The overall catalytic performance of IO-CAT was much greater than that of IO-U and comparable to that of PFe-CAT. This strongly demonstrates new potential for economical and eco-friendly preparation of iron-based catalysts for LT-FTS.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311408-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Ning Wei, Ying Liu, Min Feng, Zhaoxia Li, Shougang Chen, Youbin Zheng, Daoai Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, hydrogenated TiO〈sub〉2〈/sub〉 anatase/rutile phase heterojunction is fabricated and used for photoelectrochemical water splitting to generate clean H〈sub〉2〈/sub〉 energy under solar light. This TiO〈sub〉2〈/sub〉 phase heterojunction photocatalyst material with core-shell structures is accurately prepared by a hydrothermal method to grow the core of rutile TiO〈sub〉2〈/sub〉 nanorod arrays and an ALD technology to form the shell of the anatase TiO〈sub〉2〈/sub〉 layer with a controllable thickness, followed with a hydrogenated treatment to introduce some disordered structures and oxygen vacancies to the TiO〈sub〉2〈/sub〉 phase heterojunction. This new structured TiO〈sub〉2〈/sub〉 photocatalyst material yields a high photocurrent density of 3.88 mA cm〈sup〉−2〈/sup〉 at 1.23 V〈sub〉vs.RHE〈/sub〉 under simulated solar light (100 mW cm〈sup〉−2〈/sup〉) with a maximum IPCE of 59.7% at the wavelength of 380 nm. These values are almost 3.8 and 7.4 times higher than that of the bare rutile TiO〈sub〉2〈/sub〉, respectively. The enhanced photoelectrochemical performances are mainly attributed to the synergistic effect of the core-shell phase heterojunction, highly ordered structure and post-hydrogenated treatment to accelarate the separation and transmission of the photogenerated electrons and holes. This hydrogenated TiO〈sub〉2〈/sub〉 core-shell phase heterojunction indicates promising potential applications in the fields of photoelectrocatalysis and photovoltaic devices under solar light.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉The controllable phase heterojunction structure is afforded with augmented light absorption, high separation of photogenerated electron and hole pairs and unique band structure derived from the synergistic effect of the disordered layer, oxygen vacancy, branched and ordered structure, and phase heterojunction. Particularly, a high photocurrent density of 3.88 mA cm〈sup〉−2〈/sup〉 is achieved by this photoelectrode.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311342-ga1.jpg" width="220" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Ke Li, Rongrong Zhang, Ruijie Gao, Guo-Qiang Shen, Lun Pan, Yunduo Yao, Kaihui Yu, Xiangwen Zhang, Ji-Jun Zou〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Manganese-cobalt spinel oxides are considered as a class of promising and low-cost electrocatalysts for oxygen reduction reaction (ORR), whose performances largely depend on their electronic structures which can be effectively optimized by defect engineering. Herein, metal defects (manganese vacancies and cobalt vacancies, 〈em〉i.e.〈/em〉 V〈sub〉Mn〈/sub〉 and V〈sub〉Co〈/sub〉) were 〈em〉in-situ〈/em〉 introduced into spinel Mn〈sub〉x〈/sub〉Co〈sub〉3-x〈/sub〉O〈sub〉4〈/sub〉〈em〉via〈/em〉 a simple solvothermal treatment followed by thermal calcination. Mn-Co glycerolate precursors not only enable controllable synthesis of spinel oxides with variable metallic ratios, but also play a key role in constructing metal defected crystals for their lamellated structure. As a result of the formation rate difference between manganese and cobalt glycerolate, a unique Mn-enriched surface is formed, leading to the increase of highly active sites for ORR. Importantly, the presence of metal defects, confirmed by XRD (X-ray diffraction), element analysis and XAFS (X-ray absorption fine structure spectroscopy), leads to greatly increased electrical conductivity and O〈sub〉2〈/sub〉 adsorption ability, thus bringing about enhanced ORR activity. Especially, metal-defected Mn〈sub〉1.5〈/sub〉Co〈sub〉1.5〈/sub〉O〈sub〉4〈/sub〉, with the optimal Mn/Co ratio, exhibits comparable activity and superior durability to those of the benchmark Pt/C in ORR and displays excellent discharge performance in Zn-air batteries for practical application. This work provides a new way to optimize the electrocatalytic performance of mixed metal spinel oxides 〈em〉via〈/em〉 rational defect engineering.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311305-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Jian Liu, Yu Yu, Ruilian Qi, Changyan Cao, Xiaoyan Liu, Yujun Zheng, Weiguo Song〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Solar-to-chemical energy conversion by photocatalytic hydrogen evolution (PHE) is critical for reduction of the pollution and storage of clean energy. To improve the solar conversion efficiency, it is highly imperative to accelerate the photocarrier separation and transportation through materials design. Herein, we describe a highly effective PHE catalyst based on in-plane benzene-ring doped g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 nanosheets heterostructure through the thermal co-polymerization of urea and 4, 4'-sulfonyldiphenol (BPS) followed by a controlled heat-etching step. The solid-state 〈sup〉13〈/sup〉C NMR confirms the existence of benzene-ring structure in g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 nanosheets. Experimental results and theoretical calculations show that the energy and electronic structure of the catalyst are optimally regulated, inducing increased light absorption and effectively accelerated separation of the photo-driven charge carriers. It exhibits enhanced photocatalytic hydrogen evolution efficiency with a PHE rate of 12.3 mmol h〈sup〉−1〈/sup〉 g〈sup〉−1〈/sup〉 (almost 12 times higher than that of pure g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 nanosheets) and the quantum efficiency of 17.7% at 420 nm.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Benzene-ring doped g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 nanosheets (BS-CN) exhibited extended light adsorption and enhanced separation/transfer of photoinduced holes and electrons, which promoted it an excellent visible-light-driven hydrogen evolution catalyst by 12-fold improvement.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311287-ga1.jpg" width="429" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Jiajia Wang, Yaqing Jiang, Aibin Ma, Jinghua Jiang, Jianqing Chen, Mingxue Li, Jianyong Feng, Zhaosheng Li, Zhigang Zou〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ta〈sub〉3〈/sub〉N〈sub〉5〈/sub〉 was potentially a high efficient semiconductor in photocatalytic and photoelectrochemical water splitting but its practical performances were unsatisfactory. The oxygen impurity, which substituted N and acted as an electron donor, was one possible source of the poor photocatalytic and photoelectrochemical activities of Ta〈sub〉3〈/sub〉N〈sub〉5〈/sub〉. In this study, 24 elements, which substituted Ta and acted as the electron acceptor, were codoped with the oxygen impurity to achieve charge compensation in Ta〈sub〉3〈/sub〉N〈sub〉5〈/sub〉. Based on the density functional theory calculations, the defect formation energies, electronic structures and carrier mobility were investigated. The results showed that the charge compensation doping method was able to improve the conduction band position of Ta〈sub〉3〈/sub〉N〈sub〉5〈/sub〉, suggesting that this method was effective to enhance water reduction ability and lower onset potential of Ta〈sub〉3〈/sub〉N〈sub〉5〈/sub〉. The Ti, Zr and Hf elements were found to be more effective than other elements because they were able to keep the carrier mobility of Ta〈sub〉3〈/sub〉N〈sub〉5〈/sub〉. Our calculation results agreed well with experiments and provided useful guidance for future investigations of Ta〈sub〉3〈/sub〉N〈sub〉5〈/sub〉.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311354-ga1.jpg" width="258" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Ewelina Grabowska, Magdalena Diak, Martyna Marchelek, Adriana Zaleska〈/p〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Qi Feng, Qi Wang, Zhen Zhang, Yongyueheng Xiong, Hanyi Li, Yao Yao, Xiao-Zi Yuan, Mark C. Williams, Meng Gu, Hong Chen, Hui Li, Haijiang Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Developing active, acid-stable and cost-effective electrocatalysts for oxygen evolution reaction (OER) is a primary challenge to directly produce hydrogen from water electrolysis. IrO〈sub〉2〈/sub〉 is the best-known catalyst in acid medium due to its good activity and stability, but it’s too expensive to be used in large amounts. To overcome this economical constraint, the use of low amount of iridium electrocatalyst is required. Recently, ruthenium pyrochlore oxides (A〈sub〉2〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7−〈/sub〉δ) as OER catalysts have drawn extensive interests due to reduced content of precious metal relative to RuO〈sub〉2〈/sub〉 or IrO〈sub〉2〈/sub〉, though their OER catalytic activity still needs to be further improved. In this work, we, for the first time, developed a highly active and stable Y〈sub〉1.85〈/sub〉Zn〈sub〉0.15〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7−〈/sub〉δ electrocatalyst, the A site doped yttrium ruthenate pyrochlore for OER. The mechanism of A site doped ruthenate pyrochlore improving OER performance is revealed. The partial substitution of Y〈sup〉3+〈/sup〉 ions by smaller Zn〈sup〉2+〈/sup〉 leads to a formation of oxygen vacancies and mixed valences of Ru (Ru〈sup〉4+〈/sup〉 and Ru〈sup〉5+〈/sup〉), which, in turn, significantly alter the electronic properties and thus the electrocatalytic activity and electrical conductivity of the developed electrocatalyst for OER. The Y〈sub〉1.85〈/sub〉Zn〈sub〉0.15〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7−〈/sub〉δ/acetylene black (AB) electrocatalyst exhibits sevenfold higher activity than the IrO〈sub〉2〈/sub〉/AB reference catalyst; twofold higher activity than Y〈sub〉2〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7−〈/sub〉δ/AB, with a Tafel slope of 36.9 mV dec〈sup〉−1〈/sup〉; and higher stability than IrO〈sub〉2〈/sub〉/AB in acidic media. Using a home-made proton exchange membrane electrolyser device, a high cell performance is achieved at 25 °C with an electrolysis current density of 0.46 A cm〈sup〉-2〈/sup〉, confirming a promising prospect of Y〈sub〉1.85〈/sub〉Zn〈sub〉0.15〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7〈/sub〉−δ electrocatalyst for practical water electrolysis applications.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311299-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Yixuan Wang, Sogand Aghamohammadi, Danyang Li, Kongzhai Li, Robert Farrauto〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A series of Nb〈sub〉2〈/sub〉O〈sub〉5-x〈/sub〉 with different structures were prepared as a carrier to manganese oxide catalysts for total oxidation of propane. The results demonstrated that a monoclinic structure of Nb〈sub〉2〈/sub〉O〈sub〉5-x〈/sub〉 pre-calcined at 1025 °C, leads to significantly and surprisingly higher catalytic oxidation activity when MnO〈sub〉x〈/sub〉 is deposited at 400 °C even with extremely low specific area (around 3.94 m〈sup〉2〈/sup〉/g) relative to the performance of MnO〈sub〉x〈/sub〉/Nb〈sub〉2〈/sub〉O〈sub〉5-x〈/sub〉 (∼〉50 m〈sup〉2〈/sup〉/g pre-calcined at 500 °C). Conversion vs temperature profiles for fresh and aged catalysts were generated and performance compared for different materials. Brunauer Emmett Teller (BET) and X-ray diffraction (XRD) were conducted to reveal the textural and structural features of niobium-based catalysts. Raman, X-ray photoelectron spectroscopy (XPS) and temperature programmed reduction (TPR) were performed to further understand the interaction between manganese and niobium oxides. Raman spectra indicated a new Nb-O-Mn species formed due to the strong interaction between the activated niobium oxide carrier at 1025 °C and manganese oxide. This study describes a synergistic catalytic oxidation effect between Mn oxides deposited on a specific phase structure of Nb〈sub〉2〈/sub〉O〈sub〉5-x〈/sub〉 with very low specific surface area. The enhanced catalytic performance is directly related to the proper ratio of Mn〈sup〉3+〈/sup〉/Mn〈sup〉4+〈/sup〉 coupled with high ratio of Nb〈sup〉4+〈/sup〉/Nb〈sup〉5+〈/sup〉 on the surface and the oxygen vacancies generated between monoclinic Nb〈sub〉2〈/sub〉O〈sub〉5-x〈/sub〉 and MnO〈sub〉x〈/sub〉.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Simplified schematic depiction of the effect of calcination temperature of niobium oxide on the propane oxidation reaction.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311251-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Wei Yan, Li Yan, Chuanyong Jing〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Metal doping is an appealing modification strategy of graphitic carbon nitride (g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉) to improve its photocatalytic activity. The interactions of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 precursors with metals, however, has often been underappreciated, which can induce great impacts on g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 formation and properties. Herein, the impacts of metals (Na, K, Ca, Mg) on the morphology, structure, and photoactivity of urea-derived g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 were investigated. Our TEM and XPS results confirmed that the interactions of doped metals with urea precursors lead to the incorporation of O atoms from urea molecules into the framework of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉. Due to the synergistic effects of the metals and structural O atoms, doped g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 performed an elevated photodegradation of antibiotics under the visible light irradiation, which was attributed to the enhanced light-harvesting and reduced charge recombination. In addition, the doped metals presented uneven regulation on the band structures and morphology of g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉. As a result, both superoxide and hydroxyl radicals were generated by g-CN-Na and g-CN-K, whereas, only superoxide radicals were involved in g-CN, g-CN-Ca and g-CN-Mg. Consequently, diversified photodegradation mechanisms for enrofloxacin (ENR) were observed that the g-CN, g-CN-Ca and g-CN-Mg reaction systems mainly attacked the piperazine moiety of ENR while g-CN-Na and g-CN-K provided additional photodegradation pathway by attacking quinolone core of ENR. The present work could provide new insights into further understanding of doping chemistry with g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311275-ga1.jpg" width="268" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 245〈/p〉 〈p〉Author(s): Meike K. Leu, Isabel Vicente, Jesum Alves Fernandes, Imanol de Pedro, Jairton Dupont, Victor Sans, Peter Licence, Aitor Gual, Israel Cano〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉An imidazolium based iron-containing ionic liquid [BMIm][Fe(NO)〈sub〉2〈/sub〉Cl〈sub〉2〈/sub〉] (BMIm = 1-〈em〉n〈/em〉-butyl-3-methyl-imidazolium) has been synthesized for the first time and fully characterized employing a wide range of techniques. The iron-based containing ionic liquid was found to be an active catalyst for the cycloaddition of CO〈sub〉2〈/sub〉 to epoxides, giving high conversions for various substrates under near ambient conditions. In addition, the catalytic system showed a good recycling performance for five consecutive reaction cycles. Key mechanistic studies demonstrated that a bifunctional catalytic system is generated 〈em〉in situ〈/em〉 by the partial dissociation of the iron-based ionic liquid into [BMIm][Cl], which results in a very efficient catalyst without the need of any additive or co-catalyst. The metal center plays a role as Lewis acid and activate the epoxide group, and the chloride anion, as part of [BMIm][Cl] moiety, acts as nucleophile and leads to the ring opening through a nucleophilic attack on the less sterically-hindered Cβ. The process is favoured by an interaction 〈em〉via〈/em〉 H-bonding between the substrate and the H–C2 of the imidazolium ring, as was demonstrated by additional experiments. Kinetic studies indicated that the process followed first-order kinetics with respect to epoxide concentration and proved the existence of a reversible coordination/de-coordination equilibrium in which the active species are generated from the [BMIm][Fe(NO)〈sub〉2〈/sub〉Cl〈sub〉2〈/sub〉] complex.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318312153-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 245〈/p〉 〈p〉Author(s): Yang Liu, Bryan R. Wygant, Kenta Kawashima, Oluwaniyi Mabayoje, Tae Eun Hong, Sang-Geul Lee, Jie Lin, Jun-Hyuk Kim, Kunio Yubuta, Wenzhang Li, Jie Li, C. Buddie Mullins〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Different WO〈sub〉3〈/sub〉 facets have different surface energies and electronic structures, and exhibit different water oxidation abilities and photocatalytic performance as a result. Because of the material’s limited photoresponse region, loading a narrow bandgap material on WO〈sub〉3〈/sub〉 is a generally known method for improving photo-harvesting. In this paper, we have synthesized WO〈sub〉3〈/sub〉 films with different crystal facet ratios. After loading BiVO〈sub〉4〈/sub〉 on these WO〈sub〉3〈/sub〉 films, we measured the photoelectrochemical (PEC) performance to investigate the effects of WO〈sub〉3〈/sub〉 facet choice on the heterojunction film electrode’s performance. We found that a high-intensity ratio of the (002) WO〈sub〉3〈/sub〉 facet in X-ray diffraction (XRD) leads to a more negative onset potential and higher photocurrents in a lower potential region. The ultraviolet photoelectron spectra show a lower work function for the 002-dominant WO〈sub〉3〈/sub〉 film compared to other WO〈sub〉3〈/sub〉 films, which may result in a higher quasi-fermi level for the heterojunction electrode. Based on the XRD results, the high-intensity ratio of the (002) WO〈sub〉3〈/sub〉 facet preferentially exposes the (020) BiVO〈sub〉4〈/sub〉 facet, which may be a reason for the better charge extraction observed at low applied potential and high faradic efficiency on PEC water splitting. Together, this results in a high hole injection efficiency for 002-dominant WO〈sub〉3〈/sub〉/BiVO〈sub〉4〈/sub〉 films compared with WO〈sub〉3〈/sub〉/BiVO〈sub〉4〈/sub〉 films favoring other WO〈sub〉3〈/sub〉 facet ratios.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318312116-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 245〈/p〉 〈p〉Author(s): Jun Wu, Guang Gao, Yong Li, Peng Sun, Jia Wang, Fuwei Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Owing to the high economic values and broad applications of diols with various alkyl chains, the development of efficient heterogeneous catalysts for the highly chemoselective synthesis of diols is highly desirable. In this work, a range of bifunctional Cu〈sub〉x〈/sub〉/Mg〈sub〉3-x〈/sub〉AlO (x = 0.5, 1, 1.5, 2) nanocatalysts derived from layered double hydroxides (LDHs) precursors were fabricated and evaluated in the selective hydrogenation of lactones to synthesize diols. Systematic structure characterizations indicated the bifunctional catalytic sites containing active Cu nanoparticles with controllable sizes and tunable base sites could be finely constructed in the Cu〈sub〉x〈/sub〉/Mg〈sub〉3-x〈/sub〉AlO catalysts. Intrinsic catalytic activity tests were conducted to reveal the structure-activity relationship in the model reaction of selective hydrogenation of γ-valerolactone (GVL) to produce 1,4-pentanediol (1,4-PeD); it was found that the optimal bifunctional Cu〈sub〉1.5〈/sub〉/Mg〈sub〉1.5〈/sub〉AlO catalyst exhibited greatly improved catalytic activity and selectivity for this reaction, which surpassed various copper-based reference catalysts; the excellent catalytic performance of Cu〈sub〉1.5〈/sub〉/Mg〈sub〉1.5〈/sub〉AlO was mainly attributed to the cooperative effect of the well-dispersed active Cu nanoparticles and the appropriate surface base sites nearby. Moreover, the bifunctional Cu〈sub〉1.5〈/sub〉/Mg〈sub〉1.5〈/sub〉AlO catalyst could be extended to other lactones with different ring sizes. This work provides a low-cost, environmentally benign and atom-economic heterogeneous catalytic system for the highly selective and sustainable synthesis of value-added diols.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318312219-ga1.jpg" width="399" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 245〈/p〉 〈p〉Author(s): Ling Li, Kevin J. Barnett, Daniel J. McClelland, Dongting Zhao, Guozhu Liu, George W. Huber〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Gas-phase dehydration of tetrahydrofurfuryl alcohol (THFA) to 3,4-2H-dihydropyran (DHP) was studied over solid acid catalysts. A γ-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 catalyst resulted in 90% DHP yield from THFA. The γ-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 deactivated due to solid coke formation but was nearly fully re-generable upon a high temperature calcination step (only 2.5% activity loss after 3〈sup〉rd〈/sup〉 regeneration). The high catalytic activity and selectivity of γ-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 was correlated to its high Lewis to Brϕnsted acid site ratio, as confirmed by ammonia temperature-programmed desorption (NH〈sub〉3〈/sub〉-TPD) and isopropylamine temperature-programmed desorption (IPA-TPD). Based on isotopic-labelling studies, a reaction mechanism was proposed in which THFA initially dehydrates into a carbenium intermediate prior to Wagner-Meerwien rearrangement into DHP. A kinetic model of THFA dehydration over γ-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 was developed according to kinetic experimental data. The best-fit model suggested the rate-determining step was the surface reaction of adsorbed THFA dissociating into adsorbed DHP and water.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311925-ga1.jpg" width="228" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 245〈/p〉 〈p〉Author(s): Myeongjin Kim, Hyun Ju, Jooheon Kim〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The sodium-air (Na–air) batteries are considered as a new promising energy storage devices due to their 1683 W h kg〈sup〉−1〈/sup〉 of high theoretical specific energy density. However, these outstanding theoretical energy density performances cannot be achieved because undesirable sluggish oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) reaction kinetics on the air cathode side causes the high overpotential gap and low round-trip efficiencies during charge-discharge process. Therefore, the development of highly active bifunctional oxygen electrocatalysts is the key strategy to obtain the low overpotential gap with high energy density performance of Na-air batteries. In this work, a novel single crystalline thallium ruthenium oxide (Tl〈sub〉2〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7〈/sub〉) with pyrochlore structure was firstly revealed as an effective bifunctional electrocatalyst. Moreover, in order to enhance the surface chemical reactivity of Tl〈sub〉2〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7〈/sub〉, the surface of Tl〈sub〉2〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7〈/sub〉 is functionalized by using the dihydrogen phosphate ion (P-Tl〈sub〉2〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7〈/sub〉) for achieving the effective and rapid charge transfer behavior. The superior bifunctional catalytic activity of P-Tl〈sub〉2〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7〈/sub〉 can be explained by the degree of covalency of Ru-O bonds in Tl〈sub〉2〈/sub〉Ru〈sub〉2〈/sub〉O〈sub〉7〈/sub〉 and enhanced covalent character by functionalized dihydrogen phosphate ion, which can afford favorable oxidation nature to Tl and Ru ions.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311846-ga1.jpg" width="395" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 245〈/p〉 〈p〉Author(s): Wenjing Sun, Huangzhao Wei, Lu yang An, Chengyu Jin, Huiling Wu, Zi-ang Xiong, Chunying Pu, Chenglin Sun〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The influence of Ce amount on catalytic behaviour of perovskite catalysts La〈sub〉1-x〈/sub〉Ce〈sub〉x〈/sub〉FeO〈sub〉3-〈/sub〉〈em〉δ〈/em〉, prepared by coprecipitation was examined in catalytic wet air oxidation (CWAO) of high concentrated acrylic acid pollutant. The catalysts with the molar ratio of Ce/ (La + Ce) upper than 0.4 exhibit high catalytic activity, and outstanding stability. Because Ce doping into the skeleton of LaFeO〈sub〉3〈/sub〉 could cause the change of iron valence state as well as the change of the reactive oxygen species and oxygen vacancies of the catalyst. Three ways of O〈sub〉2〈/sub〉 involved in this reaction were considered, a synergistic mechanism of oxygen vacancies, the reversible electronic transition Fe〈sup〉3+〈/sup〉↔ Fe〈sup〉2+〈/sup〉, and direct oxidization of acrylic acid. First-principles calculations revealed that the oxygen vacancy is more easily to form in the case of Ce content increasing in La〈sub〉1-x〈/sub〉Ce〈sub〉x〈/sub〉FeO〈sub〉3-〈/sub〉〈em〉δ〈/em〉, and oxygen would adsorb on oxygen vacancy to form reactive oxygen species. Consequently, the reactive oxygen species (O*) could oxidize acrylic acid. In this process, Fe ions of higher valence sate which would attack organic compounds and itself was reduced to Fe〈sup〉2+〈/sup〉 to achieve catalytic cycles. Finally, the reaction was verified as first order, which was well explained by a proposed generalized kinetic model, in good accordance with our experimental data.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311779-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Weiyi Chen, Bin Han, Chen Tian, Xueming Liu, Shujie Liang, Hong Deng, Zhang Lin〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Reducing carbon dioxide (CO〈sub〉2〈/sub〉) to various value-added chemical products by photocatalysis could effectively alleviate the serious problems of global warming and energy shortages. Currently, most commonly prepared photocatalysts present poor performance under visible light irradiation. In this study, we adopted a facile, scalable and controllable approach to prepare ultrathin two-dimensional (2D) porous Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 catalysts (Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-NS) by air calcining of the ultrathin metal-organic framework (MOFs) nanosheet templates to validly reduce CO〈sub〉2〈/sub〉 with a Ru-based photosensitizer under visible light irradiation. Benefitting from the structural nature of MOFs precursors, the calcined Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-NS inherit the morphology of 2D and well-developed porosity, which support the transport of electrons, enhance the adsorption of CO〈sub〉2〈/sub〉 molecules, and render abundant catalytic sites for CO〈sub〉2〈/sub〉 activation. As a result, the CO generation rate is approximately 4.52 μmol·h〈sup〉−1〈/sup〉 with selectivity of 70.1%, which is superior to the Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 bulk catalysts (Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉-BK). Additionally, density functional theory (DFT) calculations reveal that the model of Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 monolayer has stronger CO〈sub〉2〈/sub〉 adsorption energy than that of the Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 bulk, which is beneficial for the CO〈sub〉2〈/sub〉-to-CO conversion. This MOF-engaged strategy provides new insight into the controlled synthesis of advanced ultrathin holey nanosheets to improve the efficiency of photocatalytic CO〈sub〉2〈/sub〉 reduction.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311998-ga1.jpg" width="228" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Xian Zhang, Miaomiao Han, Guoqiang Liu, Guozhong Wang, Yunxia Zhang, Haimin Zhang, Huijun Zhao〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We successfully synthesize Cu〈sub〉3〈/sub〉P nanosheets and granular Ni〈sub〉2〈/sub〉P nanocrystals on the surface of commercial carbon fiber cloth (CFC) (Cu〈sub〉3〈/sub〉P/CFC and Ni〈sub〉2〈/sub〉P/CFC) respectively by a vapor-phase hydrothermal route. The as-synthesized Ni〈sub〉2〈/sub〉P/CFC and Cu〈sub〉3〈/sub〉P/CFC as electrodes all show the bifunctional electrocatalytic performances towards hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), simultaneously all demonstrating the electrocatalytic activities of the furfural hydrogenation reaction (FHR) and furfural oxidation reaction (FOR) in alkaline media. Comparatively, the Cu〈sub〉3〈/sub〉P/CFC exhibits higher FHR activity with almost ∼100% selectivity of the furfuryl alcohol (FAL) product and high Faradaic efficiency (FE) of 92.0%–98.0% over the applied potential range of −0.05 to −0.55 V (〈em〉vs〈/em〉. RHE), while the Ni〈sub〉2〈/sub〉P/CFC indicates higher FOR activity with almost ∼100% selectivity of furoic acid (FA) product and FE of 90.0%–98.0% at the applied potential of 1.2–1.7 V (〈em〉vs〈/em〉. RHE) in alkaline electrolyte containing 50 mM furfural. The DFT calculations results reveal that the (1–10) dominated Cu〈sub〉3〈/sub〉P can obtain higher hydrogen coverage but restricted H〈sub〉2〈/sub〉 desorption compared to the (001) dominated Ni〈sub〉2〈/sub〉P, therefore the adsorbed active hydrogen (H) atoms from water can be effectively used for the FHR process, resulting in high FE and current density. The superior FOR activity of the Ni〈sub〉2〈/sub〉P/CFC is mainly stemmed from the formed high valence state Ni species during electrocatalysis. Thanks to the superior FHR performance of Cu〈sub〉3〈/sub〉P/CFC and FOR activity of Ni〈sub〉2〈/sub〉P/CFC, a two-electrode H-type electrocatalysis system assembled with the Cu〈sub〉3〈/sub〉P/CFC as cathode and Ni〈sub〉2〈/sub〉P/CFC as anode can be constructed for simultaneously electrocatalytic production of FAL and FA with almost ∼100% selectivity in 1.0 M KOH electrolyte containing 50 mM furfural in each chamber under the given experimental conditions, demonstrating high FE of 97%–99%.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311780-ga1.jpg" width="303" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Maged N. Shaddad, Prabhakarn Arunachalam, Joselito Labis, Mahmoud Hezam, Abdullah M. Al-Mayouf〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉BiVO〈sub〉4〈/sub〉 is one of the most promising semiconductors for photoelectrochemical water splitting. BiVO〈sub〉4〈/sub〉 is, however, limited by poor charge separation and slow oxygen evolution dynamics, for which surface modification with oxygen evolution catalysts (OECs) becomes indispensable. Among many OECs, Prussian blue type coordination polymers have lately attracted an escalating research interest attributable to their low cost, chemical robustness and easy synthesis using nontoxic earth-abundant elements. In this study, we report a simple method for efficient surface modification of Zr-doped BiVO〈sub〉4〈/sub〉 nanostructured electrodes with an amorphous Ni-Fe based Prussian blue (NiFePB) polymer. The method resulted in a remarkable 10-fold enhancement of photocurrent (3.23 mAcm〈sup〉−2〈/sup〉 at 1.23 V versus the reversible hydrogen electrode RHE) and a low onset potential of 0.208 V versus RHE, which are both records for Prussian blue (PB) type materials. Our coating method results in a (Zr)BiVO〈sub〉4〈/sub〉/NiFePB core-shell structure, in which a 10–15 nm NiFePB shell makes a superior conformal coating with complete coverage on the (Zr)BiVO〈sub〉4〈/sub〉 nanoparticles. The high conformity and amorphous nature of the coating are believed to be key features for the high photocatalytic activity and for a high photocorrosion resistance of the photoanodes during 〉 50 h of AM1.5 G solar illumination. Our method illustrates the large potential of Prussian blue type materials, when properly coated, as efficient and highly stable OECs.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311378-ga1.jpg" width="489" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 245〈/p〉 〈p〉Author(s): Fabrizio Sordello, Ilaria Berruti, Chiara Gionco, Maria Cristina Paganini, Paola Calza, Claudio Minero〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The photocatalytic performance of pristine and rare earth elements (La, Ce, Pr, Er, Yb) doped zinc oxide was tested toward the abatement of a model pollutant in MilliQ water and wastewater matrices. ZnO doped with Ce, Er and particularly with Yb exhibited photoactivity higher than bare zinc oxide and the benchmark TiO〈sub〉2〈/sub〉 P25, especially in wastewater matrix. Several electrochemical investigations were performed via chronopotentiometry and cyclic voltammetry aimed to shed light on the reasons why the diverse materials behaved differently. From the overall data a complex picture emerged, where there is not a single property of the materials evidently outperforming the others. Nonetheless, from the analysis of whole data a limited role of doping emerged for La and Pr, doping with Er improved the photocurrent, doping with Yb favored a better accumulation of photoelectrons, and doping with Ce promoted a faster electron transfer.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318312062-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 245〈/p〉 〈p〉Author(s): Fabiola Navarro-Pardo, Xin Tong, Xin Tong, Gurpreet S. Selopal, Sylvain G. Cloutier, Shuhui Sun, Ana C. Tavares, Haiguang Zhao, Zhiming M. Wang, Federico Rosei〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Low-cost nanostructured hybrid materials and the optimization of their structural design present an opportunity to achieve high performance and stable renewable energy devices. Here we used electrospinning to homogeneously embed graphene oxide (GO) nanosheets within the one-dimensional structure of cobalt-based nanohybrids (CoNHs). In particular, we focus on the performance of these nanohybrids in Na〈sub〉2〈/sub〉S/Na〈sub〉2〈/sub〉SO〈sub〉3〈/sub〉 aqueous electrolyte (pH = 13) due to its wide application in photocatalytic and photoelectrochemical (PEC) devices. We demonstrate that the addition of GO can remarkably reduce the charge transfer resistance from 4.4 Ω to 2.5 Ω for the 0 wt% GO/CoNHs and the 12 wt% GO/CoNHs, respectively. Furthermore, the CoNHs display outstanding electrochemical long-term stability, as the overpotential required to keep 〈em〉J〈/em〉 = −10 mA cm〈sup〉−2〈/sup〉 is invariable for over 42 h. The structural characterization of the nanohybrids indicates that during continuous operation, the CoNHs rebuild and regenerate 〈em〉in situ〈/em〉 leading to the formation of two-dimensional nanostructures comprising a mixture of cobalt chalcogenides (Co〈sub〉3〈/sub〉S〈sub〉4〈/sub〉 and CoS〈sub〉2〈/sub〉). The integration of the CoNHs in a quantum-dot based PEC cell and an alkaline electrolyzer (1 M KOH) demonstrates the versatility and viability of these alternative electrodes toward active and solar-driven fuel generation.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311949-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 245〈/p〉 〈p〉Author(s): Lishan Peng, Xingqun Zheng, Li Li, Ling Zhang, Na Yang, Kun Xiong, Hongmei Chen, Jing Li, Zidong Wei〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Precise atomic-level control of composition and geometric structure at the interface between two catalyst components can effectively tune the catalytic properties. Herein, we found a “chimney effect” formed on the interface between the metal oxide and Nickel metal for the hydrogen evolution reaction, using density functional theory calculations and experimental methods. This special chemical environment around the interface leads the neighboring sites to be immune to the H〈sub〉2〈/sub〉O* and OH* adsorption and to only selectively adsorb H* properly. Meanwhile, it is also beneficial for the smooth adsorption of the reactant (H*) on the interface and the easy desorption of the product (H〈sub〉2〈/sub〉) from the catalyst surface (ΔG〈sub〉H*〈/sub〉 close to zero). This phenomenon appears similar to a chimney of hydrogen evolution around the metal oxide/metal interface. Such “chimney effect” is a result of the interfacial charge transfer between the metal and metal oxide, and should be the nature of the interface-induced synergistic effect in metal oxide/metal composite catalysts for HER. Experiments further confirm that the catalytic activity of metal oxide/metal composites for HER can be enhanced by increasing the amount of the chimney - the interfacial metal atoms.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Herein, a “chimney effect” formed on the interface between the metal oxide and nickel metal for the hydrogen evolution reaction is confirmed by using density functional theory calculations and experimental methods.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311883-ga1.jpg" width="269" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 15 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 245〈/p〉 〈p〉Author(s): Dehua Xia, Huadan Liu, Bohong Xu, Yunchen Wang, Yuhong Liao, Yajing Huang, Liqun Ye, Chun He, Po Keung Wong, Rongliang Qiu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Atomic level Ag loaded MnO〈sub〉2〈/sub〉 porous hollow microspheres (Ag/MnO〈sub〉2〈/sub〉 PHMs) were prepared by redox precipitation method, and utilized for 〈em〉E. coli〈/em〉 inactivation under solar light irradiation. Ag nanoparticles (NPs) can be downsized into single atoms, thereby realizing highly utilization of Ag element as well as achieving superior photothermocatalytic 〈em〉E. coli〈/em〉 inactivation for Ag/MnO〈sub〉2〈/sub〉 than MnO〈sub〉2〈/sub〉 PHMs. Under attack by the optimal 0.3%Ag/MnO〈sub〉2〈/sub〉 PHMs with atomic Ag, 7.11 log〈sub〉10〈/sub〉 cfu/mL cells can be completely inactivated within 10 min, much faster than the 0.3%Ag/MnO〈sub〉2〈/sub〉 PHMs with Ag cluster (3.3 log〈sub〉10〈/sub〉 cfu/mL) prepared by photodeposition method, demonstrating the feasibility of redox precipitation to prepare efficient catalyst for water disinfection. Three effects are believed to contribute to this bacterial inactivation enhancement: (1) atomic Ag with high conductivity induces more formation of Mn〈sup〉3+〈/sup〉 and oxygen vacancies in MnO〈sub〉2〈/sub〉, which can efficiently accelerate the separation of hot electrons and holes generated by MnO〈sub〉2〈/sub〉, collectively work with itself generated hot electrons to form into reactive species for photocatalysis; (2) atomic Ag exhibits strong local heating effect and induces higher reducibility for MnO〈sub〉2〈/sub〉, considerably enhances the photothermal conversion and lattice oxygen activity of MnO〈sub〉2,〈/sub〉 thus promoting the thermocatalysis; and (3) the synergism of solar light driven photocatalysis and thermocatalysis through the activated O〈sub〉L〈/sub〉. The highly efficient photothermocatalysis make the designed 3D atomic Ag/MnO〈sub〉2〈/sub〉 PHMs have a promising antibacterial ability for cleaning the microbial contaminated water environment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318312098-ga1.jpg" width="297" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Vignesh Kumaravel, Snehamol Mathew, John Bartlett, Suresh C. Pillai〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hydrogen (H〈sub〉2〈/sub〉) production 〈em〉via〈/em〉 photocatalytic water splitting is one of the most promising technologies for clean solar energy conversion to emerge in recent decades. The achievement of energy production from water splitting would mean that we could use water as a fuel for future energy need. Among the various photocatalytic materials, titanium dioxide (TiO〈sub〉2〈/sub〉) is the dominant and most widely studied because of its exceptional physico-chemical characteristics. Surface decoration of metal/non-metal on TiO〈sub〉2〈/sub〉 nanoparticles is an outstanding technique to revamp its electronic properties and enrich the H〈sub〉2〈/sub〉 production efficiency. Metal dopants play a vital role in separation of electron-hole pairs on the TiO〈sub〉2〈/sub〉 surface during UV/visible/simulated solar light irradiation. In this paper, the basic principles, photocatalytic-reactor design, kinetics, key findings, and the mechanism of metal-doped TiO〈sub〉2〈/sub〉 are comprehensively reviewed. We found that Langmuir-Hinshelwood kinetic model is commonly employed by the researchers to demonstrate the rate of H〈sub〉2〈/sub〉 production. Copper (Cu), gold (Au) and platinum (Pt) are the most widely studied dopants for TiO〈sub〉2〈/sub〉, owing to their superior work function. The metal dopants can amplify the H〈sub〉2〈/sub〉 production efficiency of TiO〈sub〉2〈/sub〉 through Schottky barrier formation, surface plasmon resonance (SPR), generation of gap states by interaction with TiO〈sub〉2〈/sub〉 VB states. The recent advances and important consequences of 2D materials, perovskites, and other novel photocatalysts for H〈sub〉2〈/sub〉 generation have also been reviewed.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092633731831138X-ga1.jpg" width="382" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 245〈/p〉 〈p〉Author(s): Uriel Caudillo-Flores, Mario J. Muñoz-Batista, Ana B. Hungría, Miguel López Haro, Marcos Fernández-García, Anna Kubacka〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work we analyze two series of samples containing tungsten and titania as cations with a W/Ti atomic ratio from 0 to 0.5. The samples are prepared by a single-pot procedure, rendering in all cases high surface area powders having a dominant anatase crystalline phase. The materials were characterized by a combination of X-ray diffraction and photoelectron spectroscopies, UV–vis and Raman spectroscopies and morphological measurements. Particular effort was carried out in analyzing the way tungsten and titani-um interact in the materials through a microscopy analysis combining dark field Scanning transmission electron microscopy (HAADF-STEM) an X-ray energy dispersive spectrometry (XEDS). Overall the results are able to spot out the samples that show a truly doped character with tungsten exclusively located at (surface and bulk) lattice positions of the anatase structure, from composite catalysts where nanosized tungsten entities are supported over the dominant anatase phase. Activity of the materials in toluene and styrene photo-transformation reactions was measured through the reaction rate and the quantum efficiency observables. The study shows that quantitative comparison requires the stringent calculation of the quantum efficiency and that both the reaction rate and the apparent quantum efficiency can lead to misleading results in terms of the most active sample(s) as well as the (positive/negative) magnitude with respect to the bare titania reference. The quantum efficiency shows that doped samples can always improve titania reference sample(s) while this is not the case for composite samples.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311858-ga1.jpg" width="441" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 245〈/p〉 〈p〉Author(s): Yawei Wang, Shu Jin, Xiaoqin Sun, Shunhang Wei, Long Chen, Xiaoxiang Xu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In spite of a strong visible light absorbance as far as 600 nm, CaNbO〈sub〉2〈/sub〉N generally exhibits poor photocatalytic activity under normal conditions because of various structural defects and poor charge mobility. In this work, we have synthesized a series of Mg-modified CaNbO〈sub〉2〈/sub〉N, i.e. CaNb〈sub〉1-x〈/sub〉Mg〈sub〉x〈/sub〉O〈sub〉2+y〈/sub〉N〈sub〉1-y〈/sub〉 (0 ≤ x ≤ 0.2), and performed a detailed investigation on their crystal structures, optical absorption and other physicochemical properties. Our results show that there is a slight shrinkage of the unit cell and a blue-shift of absorption edges upon Mg incorporation into CaNbO〈sub〉2〈/sub〉N. The nitrogen contents as well as defects levels can be effectively tuned by altering the content of Mg. More strikingly, photocatalytic oxygen productions are much improved after Mg modifications under visible light irradiation (λ ≥ 420 nm). An average oxygen production rate as much as ∼126.8 umol h〈sup〉−1〈/sup〉 and an apparent quantum efficiency as high as ∼3.4 % at 420 ± 20 nm is achieved for CaNb〈sub〉0.9〈/sub〉Mg〈sub〉0.1〈/sub〉O〈sub〉2+y〈/sub〉N〈sub〉1-y〈/sub〉 (x = 0.1). These improvements probably stem from a substantial decrease of Nb〈sup〉4+〈/sup〉 defects in CaNbO〈sub〉2〈/sub〉N as well as slight positive shift of valence band maximum (VBM) after Mg modifications. Meanwhile, photoelectrochemical analysis suggests charge migration is somewhat enhanced in response to Mg modifications.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Introducing Mg into the B site of CaNbO〈sub〉2〈/sub〉N helps to decrease defects levels, enhance charge mobility and separation, positively shift valence band maximum, all of which contributes to improved photocatalytic activity for water oxidation reactions.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092633731831186X-ga1.jpg" width="263" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 15 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 245〈/p〉 〈p〉Author(s): T.B. Shoynkhorova, P.V. Snytnikov, P.A. Simonov, D.I. Potemkin, V.N. Rogozhnikov, E.Y. Gerasimov, A.N. Salanov, V.D. Belyaev, V.A. Sobyanin〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉It was investigated how the modification of Ce〈sub〉1-x〈/sub〉Zr〈sub〉x〈/sub〉O〈sub〉2–δ〈/sub〉 with alumina as structural additive affected the surface characteristics of the support. The effect of alkaline promoters on the catalyst coking resistance and activity was studied. Sorption-hydrolytic deposition technique was used to prepare a set of catalysts containing 1 wt.% Rh deposited on Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 - Ce〈sub〉0.75〈/sub〉Zr〈sub〉0.25〈/sub〉O〈sub〉2-δ〈/sub〉, Ce〈sub〉0.75〈/sub〉Zr〈sub〉0.25〈/sub〉O〈sub〉2-δ〈/sub〉 and Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 - Ce〈sub〉0.75〈/sub〉Zr〈sub〉0.25〈/sub〉O〈sub〉2-δ〈/sub〉, doped with alkaline metal. The catalysts were characterized by BET, TEM, SEM, XRD, TPO, and CO chemisorption methods. It was proved that the catalysts contained high-dispersion Rh particles of size 1–2 nm. The presence of Al deteriorated catalytic activity of Rh/ Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 - Ce〈sub〉0.75〈/sub〉Zr〈sub〉0.25〈/sub〉O〈sub〉2-δ〈/sub〉 for steam reforming of diesel surrogate (n-hexadecane) at T = 550 °C, H〈sub〉2〈/sub〉O/C = 3.0, GHSV = 20,000 h〈sup〉−1〈/sup〉, whereas the alkaline additives promoted n-hexadecane steam reforming. Rh/Ce〈sub〉0.75〈/sub〉Zr〈sub〉0.25〈/sub〉O〈sub〉2-δ〈/sub〉 appeared to be the most stable catalyst, as it provided 100% conversion of n-hexadecane during 15 h on stream. The active component Rh/Ce〈sub〉0.75〈/sub〉Zr〈sub〉0.25〈/sub〉O〈sub〉2-δ〈/sub〉 was supported on FeCrAl alloy wire mesh using alumina as a binding structural component. The obtained catalyst Rh/Ce〈sub〉0.75〈/sub〉Zr〈sub〉0.25〈/sub〉O〈sub〉2-δ〈/sub〉-ƞ-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉/FeCrAl was tested in the autothermal reforming of n-hexadecane at various temperatures and gas flow rates. Operating conditions were found to provide a 100% conversion of n-hexadecane and stable catalyst activity.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311901-ga1.jpg" width="374" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 245〈/p〉 〈p〉Author(s): Song Lei, Qiao-Hong Li, Yao Kang, Zhi-Gang Gu, Jian Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The development of cost-effective, high-efficiency, and non-noble metal based electrocatalysts for oxygen evolution reaction (OER) is considered to be the most pivotal portion for electrochemical water splitting to generate renewable energy. Herein, well-aligned mesoporous CoFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 thin film is first developed from surface epitaxial growth of oriented CoFe-based prussian blue analogue thin film (CoFe-PBA thin film) for efficient electrocatalytic OER. CoFe-PBA thin film with preferred [100] orientation is first prepared on the substrate surface by employing liquid phase epitaxial method without any structure-directing surfactants. After thermal pyrolysis, such CoFe-PBA thin film was transformed into well-aligned mesoporous CoFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 thin film. Interestingly, the self-support CoFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 thin film electrode with the mass loading of 1.6 mg cm〈sup〉−2〈/sup〉 delivers an oxygen evolution current density of 10 mA cm〈sup〉−2〈/sup〉 at an overpotential of 266 mV and exhibits durable stability in 1 M KOH aqueous solution. The remarkable and stable catalytic performance of the CoFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 thin film can be mainly owing to the mesoporous structure of CoFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉, efficient charge/electron transfer, the numerous exposed active sites, and the well-structured configuration of the electrode. Hence, this work provides an effective paradigm for preparing binder-free, self-support, and low-cost spinel oxide electrocatalyst for efficient OER derived from surface epitaxial growth of oriented PBA thin film.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉We first developed a well-aligned mesoporous CoFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 thin film from surface epitaxial growth of oriented CoFe-based prussian blue analogue thin film (CoFe-PBA thin film) for efficient electrocatalytic OER. CoFe-PBA thin film with preferred [100] orientation is first prepared on the substrate surface by employing liquid-phase epitaxial method without any structure-directing surfactants. After thermal pyrolysis, such CoFe-PBA thin film was transformed into well-aligned mesoporous CoFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 thin film with remarkable catalytic performance and durable stability. This study provides an effective paradigm for preparing binder-free, self-support and low-cost spinel oxide electrocatalyst for efficient OER derived from surface epitaxial growth of oriented PBA thin film.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311895-ga1.jpg" width="361" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Xuexue Cui, Yunshi Xu, Leilei Chen, Mingyu Zhao, Shuguang Yang, Yi Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Constructing ultrafine and highly dispersive palladium nanoparticles on 3-dimentional hierarchically porous carbon matrix is of great significance to develop high-performance and cost-effective electrocatalysts for fuel cell systems. Herein, a facile and stabilizer-free strategy was exploited to decorate of ultrafine and well-dispersive Pd nanoparticles (∼2.8 nm) on mesocellular graphene network (MGN) that was templated by zeolite MCM-22. It was found that optimal oxygen defects in MGN templated by zeolite framework Al sites were contributed to the ultrafine structure. The as-prepared Pd/MGN not only inherited the nanosheet structure of zeolite MCM-22 with hierarchical pores, large surface area and high conductivity, but also exhibited plentiful and accessible catalytic active sites. In comparison with the commercial platinum-carbon (Pt/C) catalyst (20 wt %), Pd/MGN demonstrated lower onset potential (positive shift 9 mV), significantly enhanced mass activity (up to 3.6 fold) and much longer durability for cathodic oxygen reduction reaction. It is believed that this work promises a straightforward method to develop carbon-supported ultrafine nanoparticles for low-cost and highly efficient catalytic applications.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311792-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Aleksei N. Marianov, Yijiao Jiang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Electrochemical reduction of CO〈sub〉2〈/sub〉 to CO in water catalysed by porphyrins is a viable way to environmentally friendly CO〈sub〉2〈/sub〉 valorisation, while efficient catalyst immobilization on the electrode surface is one of the key challenges to answer. Herein we present a concept of “molecular wire” i.e. connection of the catalyst to electrode via a conductive covalent linker. To covalently immobilize Co porphyrin core onto carbon cloth we employed reduction of corresponding diazonium salt. “Wiring” via resulting phenylene group had profound effect on electrocatalytic performance. Formation of CO in neutral aqueous electrolyte at –1.05 V vs NHE (η = 500 mV) occurs with TOF of 8.3 s〈sup〉−1〈/sup〉 while noncovalent counterpart has TOF of 4.5 s〈sup〉−1〈/sup〉 only. Compared to the noncovalent mode, covalent ligation leads to 2.4 times higher surface density of electrochemically active species and maximum FE (CO) is achieved at 50 mV less negative potential. The catalyst accumulated 3.9‧10〈sup〉5〈/sup〉 TON in 24 h long electrolysis surpassing performance of drop-cast analogue by a factor of 3 and showed FE (CO) of up to 81%. Notably, the TON and TOF values achieved in our study are one of the highest reported to date surpassing those measured for Fe hydroxyporphyrins and Co porphyrin-based covalent organic frameworks. Electrokinetic analysis demonstrated that the electron transfer from electrode onto porphyrin moiety plays an important role in overall reaction kinetics and conductive link with the support is a key element of heterogeneous catalyst design.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311421-ga1.jpg" width="325" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Stella G. Michael, Irene Michael-Kordatou, Vasiliki G. Beretsou, Thomas Jäger, Costas Michael, Thomas Schwartz, Despo Fatta-Kassinos〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This work evaluated the removal of a mixture of antibiotics from urban wastewater, by a combined process consisting of solar photo-Fenton (SPF) followed by granular activated carbon (GAC). The effects of the SPF process were investigated at a toxicological, microbiological and genomic level, using species of plants and aquatic organisms, bacteria, antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs). The results demonstrated that SPF could completely degrade antibiotics present in two types of effluent deriving from a conventional activated sludge system (CAS) and a membrane bioreactor (MBR), operated at the optimum oxidant dose ([H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉]〈sub〉CAS〈/sub〉 = 100 mg/L; [H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉]〈sub〉MBR〈/sub〉 = 50 mg/L) and illumination time (t〈sub〉CAS〈/sub〉 = 115 min; t〈sub〉MBR〈/sub〉 = 111 min) at acidic pH (2.8–2.9). Moreover, total disinfection was achieved by the SPF process, as cultivable bacteria, including ARB, were inactivated after 60 min of treatment, disabling also the bacterial regrowth after 24 h of storage of the treated effluent. Furthermore, SPF was shown to be effective in degrading the cellular DNA of the effluent, which was reduced to the detection limit after 60 min of treatment in both effluents. The abundance of 16S rRNA was found to be preferentially decreased by the SPF in the MBR-treated effluent (8 folds) compared to the CAS-treated effluent (7.4 folds). The abundance of 〈em〉bla〈/em〉〈sub〉OXA〈/sub〉, 〈em〉bla〈/em〉〈sub〉CTX-M〈/sub〉, 〈em〉qnrS〈/em〉, 〈em〉sul〈/em〉1, and 〈em〉tet〈/em〉M genes was decreased to the limit of quantification after 60 min of SPF treatment in both effluents. However, the SPF treated flow resulted in increased toxicity, probably due to the oxidation of the dissolved effluent organic matter of the wastewater leading to the formation of toxic products. Therefore, SPF-treated samples collected at different time intervals (30, 60, 90, 120, and 180 min) were subjected to adsorption onto GAC (500 mg/L), and the removal of both the toxicity and the residual antibiotics remaining after SPF, was explored. The combined processes (30 min SPF; 15 min GAC) provided almost complete removal of toxicity and elimination of antibiotics, ensuring wastewater decontamination.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311834-ga1.jpg" width="330" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Q. Zhang, L. Pastor-Pérez, W. Jin, S. Gu, T.R. Reina〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Mo〈sub〉2〈/sub〉C is an effective catalyst for chemical CO〈sub〉2〈/sub〉 upgrading via reverse water-gas shift (RWGS). In this work, we demonstrate that the activity and selectivity of this system can be boosted by the addition of promoters such as Cu and Cs. The addition of Cu incorporates extra active sites such as Cu〈sup〉+〈/sup〉 and Cu° which are essential for the reaction. Cs is an underexplored dopant whose marked electropositive character generates electronic perturbations on the catalyst’s surface leading to enhanced catalytic performance. Also, the Cs-doped catalyst seems to be 〈em〉in-situ〈/em〉 activated due to a re-carburization phenomenon which results in fairly stable catalysts for continuous operations. Overall, this work showcases a strategy to design highly efficient catalysts based on promoted β-Mo〈sub〉2〈/sub〉C for CO〈sub〉2〈/sub〉 recycling via RWGS.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311767-ga1.jpg" width="354" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Yanan Liu, Chenglin Miao, Pengfei Yang, Yufei He, Junting Feng, Dianqing Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The ultrathin TiO〈sub〉2〈/sub〉 nanosheets (TiO〈sub〉2〈/sub〉-U) with abundant defects were successfully fabricated as substrates to support well-dispersed Pt nanoparticles with low metal loading by photochemical route (P), with impregnated Pt/TiO〈sub〉2〈/sub〉-U, Pt/TiO〈sub〉2〈/sub〉-bulk and photoreduced Pt/TiO〈sub〉2〈/sub〉-bulk as control samples, to focus on studying the inductive effect of oxygen vacancy-rich ultrathin TiO〈sub〉2〈/sub〉 on highly dispersed Pt nanoparticles, and their synergetic promotional effect for CO〈sub〉2〈/sub〉 photoreduction. As expected, P-Pt/TiO〈sub〉2〈/sub〉-U exhibited excellent photocatalytic efficiency for the selective conversion of CO〈sub〉2〈/sub〉 into CH〈sub〉4〈/sub〉 and CO. The ultrathin TiO〈sub〉2〈/sub〉 nanosheets with a large number of low coordinative sites and ultralarge surface area promoted the rate of electron-transfer. The ultrafine Pt nanoparticles induced by photochemical strategy facilitated the efficient separation of electron–hole pairs. Furthermore, the synergy of metal and support improved the adsorption ability of CO〈sub〉2〈/sub〉. These three factors were considered to drive jointly the enhancement of catalytic performance in this system. This work offers deep insights for the design of highly efficient catalysts with coordinatively unsaturated sites for CO〈sub〉2〈/sub〉 photoconversion in the presence of H〈sub〉2〈/sub〉O.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311822-ga1.jpg" width="388" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): A. Morales-Marín, J.L. Ayastuy, U. Iriarte-Velasco, M.A. Gutiérrez-Ortiz, Chemical Technologies for the Environmental Sustainability Group〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bulk nickel aluminate (NiAl〈sub〉2〈/sub〉O〈sub〉4〈/sub〉) was synthesised by co-precipitation at a Ni/Al mole ratio of 1:2 (stoichiometric ratio). The prepared sample was reduced at different temperatures, in the 300 to 850 °C range, and obtained assays were analysed by a wide range of analytical techniques (XFR, XRD, H〈sub〉2〈/sub〉-chemisoprtion, H〈sub〉2〈/sub〉-TPR, DRS UV–vis NIR, FTIR, 〈sup〉27〈/sup〉Al MAS NMR, NH〈sub〉3〈/sub〉-TPD, CO〈sub〉2〈/sub〉-TPD, TPO) and tested for the APR of glycerol. The spinel precursor allowed the formation of small and stable Ni particles (〈14 nm) upon reduction with good performance in the APR of glycerol (NiAl-850 93% conversion, 57% conversion to gas, at 250 °C/45 bar and WHSV 24.5 h〈sup〉−1〈/sup〉). Hydrogen was the main gaseous product and the activation temperature did not substantially alter selectivity to gaseous products; however, selectivity to intermediate oxygenated liquid compounds was substantially modified. Overall, glycerol dehydrogenation route was dominant at high reduction temperature. The good stability of the spinel led to stable H〈sub〉2〈/sub〉 yield in the long-term runs (50 h) and proved potential to be used in the APR of glycerol.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311731-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Guangyan Xu, Jinzhu Ma, Lian Wang, Wen Xie, Jingjing Liu, Yunbo Yu, Hong He〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The sulfur tolerance of Ag/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 catalysts in H〈sub〉2〈/sub〉-assisted C〈sub〉3〈/sub〉H〈sub〉6〈/sub〉-SCR was investigated by UV–vis, TPR, TPSR, DRIFTS-MS, and DFT calculations. Ag/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 with higher silver loadings exhibited better deNO〈em〉x〈/em〉 performance and sulfur tolerance, especially the 4% Ag/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 catalyst. UV–vis and H〈sub〉2〈/sub〉-TPR revealed that highly dispersed Ag〈sup〉+〈/sup〉 cations were predominant on 2% Ag/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉, while more metallic Ag clusters with large sizes were present on the 4% Ag/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉. After exposure to SO〈sub〉2〈/sub〉, large amounts of sulfates were adsorbed on the Ag sites and Al sites of the Ag/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 surface. The sulfates were reduced to H〈sub〉2〈/sub〉S and SO〈sub〉2〈/sub〉 in a reducing atmosphere, while they showed little decomposition under real SCR reaction conditions. DRIFTS-MS experiments showed that sulfate species transferred rapidly between Ag sites and Al sites on the Ag/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 catalysts with higher amounts of Ag clusters. DFT calculations revealed that Ag〈sub〉1〈/sub〉 cations show stronger affinity for sulfate species than Ag clusters, thus resulting in blockage by sulfates at the Ag-O-Al interface. Such blocking by sulfates suppressed the activation of C〈sub〉3〈/sub〉H〈sub〉6〈/sub〉 as well as the formation of -NCO species, and thus severely inhibited the deNO〈em〉x〈/em〉 performance of 2% Ag/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉. In contrast, the rapid mobility of sulfate species on 4% Ag/Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 made more active sites available for the formation of key intermediates of HC-SCR, finally contributing to its excellent sulfur tolerance.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311007-ga1.jpg" width="426" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 245〈/p〉 〈p〉Author(s): Jinshui Cheng, Zhao Hu, Qin Li, Xiaofang Li, Shun Fang, Xiaofeng Wu, Mei Li, Yaobin Ding, Bing Liu, Changjun Yang, Lili Wen, Yi Liu, Kangle Lv〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As a typical visible-light-responsive organic semiconductor photocatalyst, graphitic carbon nitride (gCN) only exhibits moderate photoreactivity beacuse of its low specific area, limited light harvesting ability and quick recombination of photo-generated carriers. Herein, we report the fabrication of gCN nanosheets (gCN-NSs) with large BET surface area, excellent visible-light-absorptive property and efficient separation of carriers by direct polymerization of amidinourea, the product from the hydrolysis of dicyandiamine (DCDA). When compared with that of bulk gCN (S0) synthesized by direct polymerization of DCDA, the visible photocatalytic hydrogen evoluation rate of gCN-NSs (S2 sample) obtained by condensation of amidinourea improved 4.9 times, which is also 2.4 times higher than that of gCN-NSs (Su sample) which is prepared by polymerization of urea. The enhanced visible photocatalytic activity gCN-NSs (S2) toward hydrogen production can be ascribed to the combined effects of enlarged BET surface that provides more active sites for adsorption and photocatalytic reaction, compacted π-π layer stacking which facilitates the efficient separation of photo-generated carriers, negatively shifted CB potential and improved hydrophilic property that favor the electron transfer at the interfaces between gCN and water. In addition, the product yield of gCN-NSs (S2 sample) from the polymerization of amidinourea is 11.9%, which is 10.8 times higher than Su sample that prepared from urea (only 1.1%).〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉High efficient visible-light-responsive carbon nitride nanosheets for H〈sub〉2〈/sub〉 production were prepared by polymerization of amidinourea, the precursor hydrolyzed from dicyandiamine.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311986-ga1.jpg" width="399" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Amr Hussein Mady, Marjorie Lara Baynosa, Dirk Tuma, Jae-Jin Shim〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Three-dimensional (3D) γ-MnO〈sub〉2〈/sub〉@ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/reduced graphene oxide (rGO) nanohybrids were synthesized using a one-pot hydrothermal self-assembly method. The morphology and properties of the nanohybrids were investigated. The synergistic interactions among γ-MnO〈sub〉2〈/sub〉, ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉, and rGO resulted in 3D nanoflakes distributed uniformly in the rGO structure with a thickness of approximately 2–5 nm, leading to a high surface area. The nanohybrid containing 10 wt. % rGO exhibited superior catalytic activities for phenol degradation through the activation of peroxymonosulfate (PMS) to generate active sulfate radicals (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mtext〉S〈/mtext〉〈msubsup〉〈mtext〉O〈/mtext〉〈mrow〉〈mn〉4〈/mn〉〈mtext〉 〈/mtext〉〈/mrow〉〈mrow〉〈mo〉•〈/mo〉〈mo〉–〈/mo〉〈/mrow〉〈/msubsup〉〈/math〉). Typically, 50 mL of a 20 ppm phenol solution was degraded completely and 85% of the carbon content had been mineralized in 30 min at 25 °C using 10 mg of the nanohybrid. The nanohybrid could be recovered easily using a magnet and reused, maintaining high stability during catalytic oxidation. The 3D γ-MnO〈sub〉2〈/sub〉@ZnFe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉/rGO nanohybrid catalyst could be applied to the removal of hard-to-degrade waste materials owing to its high efficiency and excellent reusability.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311445-ga1.jpg" width="481" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Jiaxiong Liu, Yajin Li, Huimin Liu, Dehua He〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Converting glycerol and CO〈sub〉2〈/sub〉 into glycerol carbonate offers a green pathway for utilizing biodiesel by-product glycerol and greenhouse gas CO〈sub〉2〈/sub〉 as well as synthesizing the important chemical compound glycerol carbonate. In this study, for the first time, the abundant visible light was introduced into thermal-driven glycerol carbonylation system, aiming to improve catalyst performance via breaking the thermodynamic equilibrium limitations. Here x%Au/ZnWO〈sub〉4〈/sub〉-ZnO catalysts were designed for the photo-thermal catalytic system. It was found that, ZnWO〈sub〉4〈/sub〉-ZnO itself was effective in glycerol carbonylation even under thermal-driven condition, and the loading of plasmonic Au further enhanced the catalytic performances especially with visible light irradiation. The visible light responsivity of the catalysts and reaction temperatures played important roles for the photo-thermal performance of x%Au/ZnWO〈sub〉4〈/sub〉-ZnO, indicating the strong photo-thermal synergistic effect for the highly promoted catalytic performance. This study suggests the photo-thermal synergistic catalysis is one of efficient approaches for further improving catalytic performance.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311718-ga1.jpg" width="339" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Chantal Kassargy, Sary Awad, Gaëtan Burnens, Gaurav Upreti, Khalil Kahine, Mohand Tazerout〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉In this work, a study of the deactivation and reuse of USY zeolite for the pyrolysis of polyethylene has been carried out in a batch reactor at 500 °C. From the different tested zeolite/plastic ratios, 1/10 is the optimal ratio which allows giving rise to a liquid product free of wax. Regeneration was established by heating at 500 °C for 3 h coked zeolite in presence of air. The liquid yield begins to increase from the 11〈sup〉th〈/sup〉 cycle of regeneration until reaching a maximum at the 14th cycle showing a lost in the zeolite activity producing a viscous product.〈/p〉 〈p〉The liquid fraction derived from the first eight cycles was a mixture of C〈sub〉4〈/sub〉-C〈sub〉27〈/sub〉 compounds with a maximum C〈sub〉5〈/sub〉-C〈sub〉7〈/sub〉 fraction. In the 14th cycle of regeneration, compounds having higher carbon number were obtained and the yield of linear compounds increases up to 29%. To explain the relative activity of the regenerated zeolite, the textural properties and the XRD patterns results of the zeolite recovered after the 1st and 14th cycles have been compared with those obtained with fresh catalyst. The study showed that after 14 cycles of regeneration, the zeolite is still active but its activity level has decreased.〈/p〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311512-ga1.jpg" width="367" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Yongwoo Kim, Do Heui Kim〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein, we investigated the effect of Pd size on a formic acid dehydrogenation (FAD) reaction. A series of size-controlled Pd/C catalysts was simply prepared by a treatment using sodium borohydride (NaBH〈sub〉4〈/sub〉), which provides 〈em〉in-situ〈/em〉 hydrogen in the aqueous phase. Pd particles in the catalyst were gradually agglomerated as the number of NaBH〈sub〉4〈/sub〉 treatments increased, resulting in the synthesis of the size-controlled Pd/C catalysts with the Pd size from 2.5 nm to 4.8 nm. The catalytic activities of the size-controlled Pd/C catalysts continuously declined with increasing the Pd size, which was attributed to the decrease in the number of active sites of the catalyst. However, the decreasing trend of turnover frequency (TOF(h〈sup〉−1〈/sup〉)) values with the Pd size at low temperature demonstrated that the intrinsic activity of the small Pd is higher than that of the large Pd. More importantly, such decreasing trends of TOF values as a function of the Pd size gradually disappeared when raising the reaction temperature. It implies that there is a thermodynamic effect of the Pd size on the FAD reaction, which was evidenced by a continuous increase in the activation energy from 44.9 kJ/mol to 63.9 kJ/mol with the Pd size. We proposed that the H〈sub〉2〈/sub〉 desorption step is the rate-determining step for FAD reaction. Such proposal can explain the size-dependent catalytic activity and the increase in the activation energy of FAD with the Pd size enlargement, as the temperature programmed hydrogen decomposition (TPHD) analysis demonstrated that the large Pd particle requires a high temperature/energy to desorb hydrogen from Pd. Consequently, it is concluded that the size-dependent catalytic activity of FAD is attributed not only to the number of active sites but also to the thermodynamic factor relating to the rate-determining step.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311615-ga1.jpg" width="379" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Hao Liu, Zhongxuan Fan, Chuanzhi Sun, Shuohan Yu, Shuai Feng, Wei Chen, Dezhan Chen, Changjin Tang, Fei Gao, Lin Dong〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Sm doped CeO〈sub〉2〈/sub〉-TiO〈sub〉2〈/sub〉 mixed oxide catalyst, which exhibited excellent activity and tolerance to H〈sub〉2〈/sub〉O and SO〈sub〉2〈/sub〉 in the NH〈sub〉3〈/sub〉-SCR reaction, was synthesized. The reasons for the high activity and SO〈sub〉2〈/sub〉 resistance of the catalyst were investigated by a series of characterization. The H〈sub〉2〈/sub〉-TPR and O〈sub〉2〈/sub〉-TPD results suggested that the reducibility and oxygen storage capacity (OSC) of CeTi catalyst were promoted by the addition of Sm species, which was beneficial for improving the activity of catalyst. The 〈em〉in situ〈/em〉 DRIFTS results revealed that the adsorptive ability of NO〈sub〉x〈/sub〉 species and activation ability of NH〈sub〉3〈/sub〉 were enhanced by Sm doping, which was also propitious to enhance the activity. XPS combined with DFT calculated results confirmed that the transfer of electron by Sm〈sup〉2+〈/sup〉+Ce〈sup〉4+〈/sup〉⇌Sm〈sup〉3+〈/sup〉+Ce〈sup〉3+〈/sup〉 circles occurred in the SmCeTi catalyst. The redox circles may be the reason of the good SO〈sub〉2〈/sub〉 tolerance of the SmCeTi catalyst, for which suppressed the electron transferring from adsorbed SO〈sub〉2〈/sub〉 to Ce〈sup〉4+〈/sup〉. Through 〈em〉in situ〈/em〉 DRIFTS and TG-DSC results, it can be concluded that the sulphation of catalyst was lowered by samarium doping into CeTi catalyst. Consequently, the SmCeTi catalyst exhibited significant SO〈sub〉2〈/sub〉 tolerance ability.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311548-ga1.jpg" width="427" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Qiangqiang Wu, Meizan Jing, Yuechang Wei, Zhen Zhao, Xindong Zhang, Jing Xiong, Jian Liu, Weiyu Song, Jianmei Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Diesel soot particles are important components of atmospheric fine particles, and the key factor in controlling soot emissions is the performance of catalysts in after-treatment systems. Herein, a series of high-efficient nanocatalysts of Pt@transition metal (Mn, Fe, Co, Ni, Cu) oxides (TMOs) core-shell nanoparticles (NPs) supported on 3D ordered macroporous (3DOM) Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 (Pt@TMO/3DOM-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉) were designed and synthesized. The strong Pt-TMO interaction at the optimized interface of Pt@TMO core-shell NPs induces the formation of coordination unsaturated active sites for activated reactants (O〈sub〉2〈/sub〉 and NO). Pt@TMO/3DOM-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 catalysts exhibit high catalytic activity dependence on the strong Pt-TMO interaction for soot oxidation, and Pt@CoO〈sub〉x〈/sub〉/3DOM-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 catalyst shows the highest catalytic activity (T〈sub〉50〈/sub〉 = 357 °C, TOF = 2.76 S〈sup〉−1〈/sup〉 ×10〈sup〉−3〈/sup〉) and the lowest apparent activation energy (52 kJ mol〈sup〉−1〈/sup〉) in the presence of O〈sub〉2〈/sub〉 (5%), NO (0.2%) and H〈sub〉2〈/sub〉O (5%). In addition, Pt@TMO/3DOM-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 catalysts exhibit excellent H〈sub〉2〈/sub〉O and SO〈sub〉2〈/sub〉 resistances during catalytic soot oxidation. Based on the results of characterizations and density functional theory calculations, the coordination unsaturated Co-based active sites have efficient catalytic performance for NO oxidation to NO〈sub〉2〈/sub〉 intermediate, which is an important reaction pathway for catalytic soot oxidation. Insight into the activity dependence on the strong Pt-TMO interaction is not only meaningful for development of advanced catalysts, but also supports the development of Pt@TMO nanoparticles for practical applications of emission reduction of diesel soot.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311524-ga1.jpg" width="468" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Runyuan Ma, Liang Wang, Hai Wang, Ziyu Liu, Mingyang Xing, Longfeng Zhu, Xiangju Meng, Feng-Shou Xiao〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Photocatalytic synthesis of hydrogen peroxide (H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉) from water and oxygen is an alternative route for clean energy storage and chemical synthesis, but still having problems with insufficient H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 productivity and solar-to-chemical energy conversion efficiency. Herein, we reported a hybrid catalyst of proton-form titania nanotube with carbon dot (HTNT-CD) that is highly efficient for the production of H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 under visible-light irradiation (λ 〉 420 nm, H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 productivity at 3.42 mmol g〈sub〉cat〈/sub〉〈sup〉−1〈/sup〉⋅h〈sup〉−1〈/sup〉), outperforming the titania catalysts containing noble metals and the carbon nitride catalysts reported previously. Multiple studies demonstrate that the protons on the HTNT-CD are crucial for the production of H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 by efficiently accelerating the half reaction of molecular oxygen reduction to form H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉, and effectively hindering H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 decomposition under the irradiation conditions. This HTNT-CD catalyst gives solar-to-H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 apparent energy conversion efficiency at 5.2%, which is even 4.9 times of that (1.06%) over the catalyst derived from commercial P25 and CDs. More importantly, the HTNT-CD is stable, giving high H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 productivity in the continuous recycle tests.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311457-ga1.jpg" width="256" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): C.B. Özkal, D. Venieri, I. Gounaki, S. Meric〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The presence of bacterial pathogens in water bodies, alongside their growing antibiotic resistance, endanger access to freshwater sources and necessitate their successful inactivation with a proper disinfection technology. In the present study, a parallel plate reactor (PPL) with immobilized photocatalyst was used as a disinfection system for the inactivation of two bacterial indicators (〈em〉Escherichia coli〈/em〉 and 〈em〉Enterococcus faecalis〈/em〉) in aqueous samples. Experiments were carried out at parallel plate reactor configuration (PPL) operated in recycling batch mode. Titanium Tetraisopropoxide (TTIP) based thin-film coated photocatalyst surfaces were used and assessed operations parameters were; pH, initial bacteria concentration, source and type of bacteria. The effect of the photocatalytic process on antibiotic resistance profile of target bacteria was also investigated as it may serve as a pioneering step in the field of well-established and modern disinfection method development, without causing proliferation of antibiotic resistance. The observed courses of bacterial inactivation and the final disinfection rates point out diversity in the level of interaction between different type/source of bacteria and photocatalyst of concern. According to the results, a stationary phase of bacteria inactivation proceeded with a rapid and efficient one for the case of 〈em〉E. faecalis〈/em〉 (99% removal after 180 min and 99.9% removal after 240 min), while the trend for 〈em〉E. coli〈/em〉 is more likely to be described as extended along the process time. Among the tested antibiotics, 〈em〉E. coli〈/em〉 Minimum inhibition concentration (MIC) values for beta-lactam, macrolide and aminoglycoside groups were considerably altered (namely Ampicillin, Cefaclor, Clarithromycin - Erythromycin and Amikacin, respectively). PC oxidation was approved to be efficient on bacterial inactivation and trigger alterations on resistance behaviour of 〈em〉E.coli〈/em〉 and 〈em〉Enterococcus〈/em〉 sp. strains.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318311536-ga1.jpg" width="313" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 244〈/p〉 〈p〉Author(s): Qijie Mo, Wenbiao Zhang, Liuqing He, Xiang Yu, Qingsheng Gao〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Exploring noble-metal-free electrocatalysts for hydrogen evolution reaction (HER) is the key issue in hydrogen economy blueprint. Herein, bimetallic Ni〈sub〉2-x〈/sub〉Co〈sub〉x〈/sub〉P supported by N-doped carbon nanofibers (denoted as Ni〈sub〉2-x〈/sub〉Co〈sub〉x〈/sub〉P/N-C NFs) are developed via electrospinning followed by pyrolysis under an inert flow. The space confinement by 〈em〉in-situ〈/em〉 formed N-doped carbon matrix produces ultrafine Ni〈sub〉2-x〈/sub〉Co〈sub〉x〈/sub〉P with abundant active-sites. More importantly, the engineering on Ni〈sub〉2-x〈/sub〉Co〈sub〉x〈/sub〉P solid-solution-alloys can vary electronic configuration and consequently optimize hydrogen binding on electrocatalyst surface, accomplishing prominent HER activity in a wide pH range. The optimal Ni〈sub〉2-x〈/sub〉Co〈sub〉x〈/sub〉P/N-C NFs afford low overpotentials (〈em〉η〈/em〉〈sub〉10〈/sub〉) of 100, 130 and 110 mV to reach a current density of -10 mA cm〈sup〉−2〈/sup〉 in 0.5 M H〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉, 1.0 KOH and 1.0 M PBS (phosphate buffer saline), respectively, performing among the best of noble-metal-free electrocatalysts. With a good functionality for oxygen evolution (〈em〉η〈/em〉〈sub〉10〈/sub〉 = 280 mV), such composite further delivers a high efficiency for overall water splitting, featuring a comparable cell voltage (1.56 V @ 10 mA cm〈sup〉−2〈/sup〉) to a commercial IrO〈sub〉2〈/sub〉/C − Pt/C couple, and remarkably better stability. Identifying electrocatalysis relying on solid-solution alloys, this work will inspire the exploration of cost-efficient electrocatalysts and the new understanding on catalytic mechanisms.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092633731831141X-ga1.jpg" width="292" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Xitao Li, Xinding Lv, Nan Li, Jiaojiao Wu, Yan-Zhen Zheng, Xia Tao〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Molybdenum disulfide (MoS〈sub〉2〈/sub〉) are proven to be a promising non-precious-metal cocatalyst for the photocatalytic hydrogen evolution reaction (HER), but the catalytic efficiency of reported MoS〈sub〉2〈/sub〉 is still poor due to its limited active sites and low conductivity. Herein, we report a facile one-step hydrothermal approach for synthesizing water-dispersed high-percentage metallic 1T-phase MoS〈sub〉2〈/sub〉 quantum dots at a reaction temperature of 180 °C (denoted as 1T-MoS〈sub〉2〈/sub〉 QDs-180). Such prepared 1T-MoS〈sub〉2〈/sub〉 QDs-180 possesses well-dispersed ultrasmall size of ∼3.3 nm and 1T-phase composition over 82%. Benefiting from the abundance of exposed catalytic edge sites, as well as the excellent intrinsic conductivity of 1T-MoS〈sub〉2〈/sub〉 QDs-180, the preformed heterostructure photocatalyst i.e. 1T-MoS〈sub〉2〈/sub〉 QDs-180 loading onto CdS nanorods (denoted as 1T-MoS〈sub〉2〈/sub〉-C) exhibits remarkably enhanced visible-light (λ 〉 420 nm) photocatalytic HER in comparison with pure CdS. Particularly, the HER rate of the optimized 3 wt.% 1T-MoS〈sub〉2〈/sub〉-C reaches climbing up to 131.7 mmol h〈sup〉−1〈/sup〉 g〈sup〉−1〈/sup〉, over 65-fold the rate of pure CdS (2.0 mmol h〈sup〉−1〈/sup〉 g〈sup〉−1〈/sup〉) and appropriately 2-fold the rate of precious-metal Pt loaded CdS (67.0 mmol h〈sup〉−1〈/sup〉 g〈sup〉−1〈/sup〉). To the best of our knowledge, our home-made 1T-MoS〈sub〉2〈/sub〉-C photocatalyst shows the highest visible-light-driven HER performance among all reported phase-engineered MoS〈sub〉2〈/sub〉 photocatalytic systems. Such a simple and propagable hydrothermal approach capable of achieving the ultrasmall-sized metallic phase transition metal dichalcogenides is applicable in green hydrogen energy production.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309895-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Jinyuan Liu, Hui Xu, Hongping Li, Yanhua Song, Jingjie Wu, Yongji Gong, Li Xu, Shouqi Yuan, Huaming Li, Pulickel M. Ajayan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Electrocatalysis of oxygen reaction is a critical step in operation of fuel cells and metal-air batteries. For the practical applications, the inexpensive non-noble metals catalysts with highly activity and stable need to be explored and utilized. Herein, a strategy for the preparation of a bi-functional rambutan shaped oxygen electrocatalyst is presented. The novel electrocatalyst is formed 〈em〉in situ〈/em〉 with N doped carbon nanotubes grown on metal encapsulated hollow-mesoporous carbon sphere (Me@N-CNT/HMCS). The Me@N-CNT/HMCS oxygen electrocatalysts show high catalytic activities towards ORR, comparable to commercial Pt/C catalyst. The optimized performance of Fe@N-CNT/HMCS was achieved with a positive onset potential of 1.012 V and half-wave potential of 0.833 V. It is emphasized that Me@N-CNT/HMCS shows high stability and enhanced tolerance against methanol in alkaline medium. The Fe@N-CNT/HMCS electrocatalyst possessed a high OER activity with a low overpotential of 0.35 V at 10 mA cm〈sup〉−2〈/sup〉 current density. The excellent performance could be attributed to the synergistic effect involving chemical composition, high conductivity, good porosity and unique rambutan-like structure. In addition, the theoretical calculation study suggests that metallic Fe cluster can promote the O〈sub〉2〈/sub〉 adsorption strength in such chemical environment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Herein, we designed a strategy to successfully synthesize a novel bi-functional rambutan-like oxygen electrocatalysts comprising 〈em〉in situ〈/em〉-formed N-doped metal (metal: Fe, Co or Ni) encapsulated carbon nanotubes grown on hollow-mesoporous carbon sphere (denoted as Me@N-CNT/HMCS). Metal acetate can catalyze melamine to generate uniformly distributed N-CNTs nanotubes at the surface of hollow-mesoporous carbon sphere. The Me@N-CNT/HMCS oxygen electrocatalysts with very low metal content show unexpectedly high catalytic activities toward both ORR, which is superior to commercial Pt/C. Especially, the optimized performance of Fe@N-CNT/HMCS is achieved with more positive onset potential (〈em〉E〈sub〉0〈/sub〉〈/em〉 = 1.012 V) and half-wave (〈em〉E〈sub〉1/2〈/sub〉〈/em〉 = 0.833 V). Additionally, this result indicated that excellent performance is attributed to the synergistic effect involve chemical composition, good conductivity, high porosity and unique rambutan-like structure.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309615-ga1.jpg" width="233" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): Angus Crake, Konstantinos C. Christoforidis, Robert Godin, Benjamin Moss, Andreas Kafizas, Spyridon Zafeiratos, James R. Durrant, Camille Petit〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In the field of photocatalysis and particularly that of CO〈sub〉2〈/sub〉 photoreduction, the formulation of nanocomposites provids avenues to design a material platform with a unique set of structural, optoelectronic and chemical features thereby addressing shortcomings of single-phase materials and allowing synergistic effects. In this work, inorganic/organic composite photocatalysts for CO〈sub〉2〈/sub〉 reduction comprised of titanium dioxide (TiO〈sub〉2〈/sub〉) and carbon nitride nanosheets (CNNS) were synthesized using a hydrothermal 〈em〉in-situ〈/em〉 growth method. Specifically, pre-formed CNNS were used to synthesize TiO〈sub〉2〈/sub〉/CNNS heterostructures with control over the TiO〈sub〉2〈/sub〉 facet formation. This synthesis approach improved the catalytic properties by increasing CO〈sub〉2〈/sub〉 adsorption capacity and facilitating charge transfer. The materials were characterised by various spectroscopic, imaging, and analytical techniques to investigate their structural (from nano- to macroscale), chemical, and optical properties. TiO〈sub〉2〈/sub〉 nanoparticles were efficiently grown on the CNNS. The CO〈sub〉2〈/sub〉 adsorption capacity of the composites was measured, and they were tested for CO〈sub〉2〈/sub〉 photoreduction under UV-Vis illumination with hydrogen as the reducing agent in a heterogeneous gas-solid system to combine CO〈sub〉2〈/sub〉 capture and conversion into a single-step process. Catalytic tests were performed without adding any precious metal co-catalyst. The composites exhibited enhanced CO〈sub〉2〈/sub〉 adsorption capacity and photocatalytic CO〈sub〉2〈/sub〉 conversion compared to their constituent materials (〉 ten-fold increase) and outperformed the TiO〈sub〉2〈/sub〉 P25 benchmark material. The TiO〈sub〉2〈/sub〉/CNNS composite with more {001} TiO〈sub〉2〈/sub〉 facets was the most catalytically active. Further investigations using transient absorption spectroscopy (TAS) revealed the control of facet formation improved interfacial transfer at the TiO〈sub〉2〈/sub〉/CNNS junction. A photocatalytic mechanism was proposed based on the spectroscopic analyses as well as the CO〈sub〉2〈/sub〉 adsorption, and CO〈sub〉2〈/sub〉 conversion results.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092633731830972X-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): Elif Can, Ramazan Yildirim〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉A database containing 540 cases from 151 published papers on photocatalytic water splitting over perovskites was constructed and analyzed using data mining tools; the factors leading high hydrogen production were identified by association rule mining while some useful heuristics for the future studies were developed by decision tree analysis. Additionally, the predictive models were developed using random forest regression.〈/p〉 〈p〉In about half of the works, the perovskites were doped by A-site, B-site or both; however, only some portion of doped catalysts had better activity than plain perovskites while doping also improved stability in some cases. The effect of co-catalyst on activity seems to be also irregular; no definitive conclusion could be drawn. The effects of preparation methods on surface area, band gap and crystal structure were noticeable. This is also observed in visible light activity; for example the materials prepared by hydrothermal synthesis method appeared to perform better under visible light. Methanol and other sacrificial agents were used in both UV and visible light tests while inorganic additives have been commonly utilized under visible light. The band gap was found to be highly predictable but it could not be directly linked to the hydrogen production. As the result, although there has been significant progress in the field, the improvement in hydrogen production appeared to be always limited; the sound solutions like ion doping to modify the band gap, use of co-catalyst for charge separation or use of additives as sacrificial agents did not to help as much as desired.〈/p〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309470-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Samuel Osei-Bonsu Oppong, Francis Opoku, Penny Poomani Govender〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In recent years, there has been a growing interest in developing highly efficient photocatalysts with a visible light active semiconductor as one of its components. Herein, visible-light-driven photocatalytic activity of Gd-TiO〈sub〉2〈/sub〉-GO nanocomposites were fabricated by sol–gel method. The photocatalytic property was evaluated for photodegradation of indigo carmine (IC) dye. The structural properties of the fabricated samples were characterised using SEM, XRD, PL, TEM, Raman, BET, EDS, elemental mapping and XPS analysis. To provide further insights into the synergistic effect, a hybrid density functional theory calculation was used to study the charge transfer, electronic and structural properties of Gd–TiO〈sub〉2〈/sub〉–GO nanocomposite. The as-fabricated nanocomposites showed improved visible light photocatalytic performance and degradation efficiency over pure TiO〈sub〉2〈/sub〉. The optimal Gd content was found to be 0.6 wt%, and the apparent pseudo-first order photodegradation rate of IC dye was 14.19-fold higher than that of pure TiO〈sub〉2〈/sub〉 nanoparticles under visible–light irradiation. Moreover, hydroxide radicals and holes were the main active species, and the hybrid nanocomposites exhibited high stability and recyclability during the IC dye degradation process. Herein, both GO sheets and Gd〈sup〉3+〈/sup〉 ion were excellent co-catalysts and their presence promote the reaction sites and synergistically enhanced the photocatalytic degradation of IC dye. Also, the smaller effective mass caused a high separation of photogenerated charge carriers, thereby promoting the photodegradation efficiency. This work offers a new understanding of designing high-performance TiO〈sub〉2〈/sub〉-based photocatalysts for wastewater treatment.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309871-ga1.jpg" width="296" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): Ying Lü, Jianfa Li, Yimin Li, Liping Liang, Huaping Dong, Kun Chen, Chunxia Yao, Zhanfeng Li, Jinxiang Li, Xiaohong Guan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Zero-valent iron (ZVI) is a popular reductant that has been successfully applied for remediation of groundwater contaminated with various pollutants, but it still suffers from surface passivation and pH increase in the reaction media. In this study, pyrite, a ubiquitous sulfide mineral in anaerobic environment, was adopted to enhance the reactivity of ZVI for removal of nitrobenzene. The synergetic effect between pyrite and ZVI was observed for nitrobenzene reduction, and the rate constant 〈em〉k〈/em〉〈sub〉obs〈/sub〉 at the initial pH (pH〈sub〉0〈/sub〉) 6.0 was enhanced by 8.55–23.1 folds due to the presence of pyrite with pyrite/ZVI mass ratio ranging from 1.0 to 6.0. Moreover, nitrobenzene could be removed effectively at pH〈sub〉0〈/sub〉 ranging from 5.0 to 10.0 in the presence of pyrite, while negligible removal of nitrobenzene by ZVI (0.5 g/L) alone was observed at pH〈sub〉0〈/sub〉 ≥7.0. ZVI sample recovered from the reacted ZVI/pyrite mixture was also more effective for nitrobenzene degradation than pristine ZVI. The mechanism study revealed that pyrite could suppress the pH increase in reaction media, boost the production of reactive Fe〈sup〉2+〈/sup〉, and activate the ZVI surface through replacing partially the passive oxide film with iron sulfide (FeS). In particular, the formation of highly reactive FeS@Fe in the reaction system of ZVI/pyrite mixture was proved by XRD, Mössbauer, XANES, XPS and SEM-EDS analyses, which provides a facile way for 〈em〉in-situ〈/em〉 sulfidation of ZVI and for enhancing the removal of contaminants with ZVI technology.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309299-ga1.jpg" width="461" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): Nobuaki Negishi, Yukari Miyazaki, Shigekazu Kato, Yingnan Yang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Evaluation of the effects of major components of groundwater systems on photocatalytic activity is essential for the development of commercial photocatalytic water purification systems. In this work, we have probed the effects of bicarbonate ion (HCO〈sub〉3〈/sub〉〈sup〉−〈/sup〉) on the photocatalytic activity of a TiO〈sub〉2〈/sub〉 ceramic photocatalyst. Two brands of mineral water, Evian and Contrex, which contain high concentrations of alkaline earth metal ions Mg〈sup〉2+〈/sup〉 and Ca〈sup〉2+〈/sup〉, were used as models for groundwater. The degradation rate of formic acid was used as an index of photocatalytic activity. The rate of HCO〈sub〉3〈/sub〉〈sup〉−〈/sup〉 degradation and changes in the type and concentration of the HCO〈sub〉3〈/sub〉〈sup〉−〈/sup〉 counterion with the progress of photocatalytic reaction were also observed. After the completion of 15 cycles of 8 h of photocatalytic reaction (total run time 120 h), the surface of the photocatalyst and precipitates formed on it were analyzed by means of X-ray diffraction analysis, Raman spectrometry, scanning electron microscopy, and energy dispersive X-ray spectrometry. We found that the photocatalytic activity was reduced with increasing HCO〈sub〉3〈/sub〉〈sup〉−〈/sup〉 concentration, irrespective of the type of counterion present. In addition, photocatalytic activity remained unchanged despite an increase in accumulation of the precipitate, which we identified as CaCO〈sub〉3〈/sub〉, on the photocatalyst surface with the progress of experimental cycles. We also observed that the concentration of formic acid and HCO〈sub〉3〈/sub〉〈sup〉−〈/sup〉 were decreased with photocatalysis when Ca〈sup〉2+〈/sup〉 was a counterion, however, no effect in presence of other metal ions, Na〈sup〉+〈/sup〉, K〈sup〉+〈/sup〉 or Mg〈sup〉2+〈/sup〉, was observed. These results show that bicarbonate ion was involved in the photocatalytic reaction when Ca〈sup〉2+〈/sup〉 was the counterion, and as a result, the photocatalytic degradation rate of formic acid was decreased and CaCO〈sub〉3〈/sub〉 precipitate was formed.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309640-ga1.jpg" width="443" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): Amir Mirzaei, Zhi Chen, Fariborz Haghighat, Laleh Yerushalmi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel fluorinated graphitic carbon nitride photocatalyst with magnetic properties was synthesized by a facile hydrothermal method and used for degradation of amoxicillin (AMX) in water. Compared to the bulk g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉, magnetic fluorinated Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 (FeGF) with a high specific surface area (243 m〈sup〉2〈/sup〉 g〈sup〉−1〈/sup〉) and easy separation from aqueous solution by magnet, led to improved photocatalytic activity in terms of AMX removal and mineralization as well as detoxification of the solution. The results showed that in comparison with a 500 W visible lamp, using a UV lamp (10 W) was considerably more effective for AMX removal, its mineralization and detoxification of the solution. Based on the measurement of accurate mass of the transformation products and their main fragments, a degradation pathway for AMX was proposed. The peak intensities of most transformation products (TPs) generated by using modified photocatalyst under UV light (UV/FeGF2) process were significantly lower than those generated by using pristine g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉, suggesting that UV/FeGF2 process produced a higher extent of mineralization and a lower accumulation of transformation by-products. Based on the use of inexpensive precursor and modifier, simple preparation, good photocatalytic activity and low energy consumption, the proposed method can guide the development of low-cost and high-performance photocatalysts.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309573-ga1.jpg" width="460" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Mengqi Yao, Ni Wang, Wencheng Hu, Sridhar Komarneni〈/p〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): Changqing Zhu, Fuqiang Liu, Chen Ling, Hao Jiang, Haide Wu, Aimin Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Graphene nanosheet-supported hollow cobalt sulfide nanocrystals (Co〈sub〉3〈/sub〉S〈sub〉4〈/sub〉@GN, CoS@GN) were fabricated via a facile ligand exchange route using metal-organic frameworks (MOFs) as self-templates. Subsequent thermal annealing induced the phase transformation of Co〈sub〉3〈/sub〉S〈sub〉4〈/sub〉 to CoS. This synthesis strategy drove the cobalt ions inside zeolitic imidazolate frameworks (ZIF-67) to migrate outwards, forming a highly reactive shell composed of abundant exposed active sites to activate peroxymonosulfate (PMS) in the sulfate radical (SO〈sub〉4〈/sub〉〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉〈sup〉−〈/sup〉)-based advanced oxidation process (SR-AOP). The graphene support exhibited excellent efficiencies in the enrichment of targeted pollutant as well as the charge transfer between absorbed molecules and radicals. The nanocatalysts were fully characterized and applied to the catalytic degradation of bisphenol A (BPA). Benefitting from the unique structure characteristic, the as-synthesized nanocomposites showed superior catalytic activities over a broad pH range. The degradation efficiency of BPA reached ∼100% within 8 min by using CoS@GN, and the kinetic constant (0.62 min〈sup〉-1〈/sup〉) was higher than those of most reported heterogeneous catalysts by 1–2 orders of magnitude. Furthermore, the critical roles of graphene support in regulating the variety and action site of radicals were addressed for the first time. The adsorptive and conductive graphene made the SO〈sub〉4〈/sub〉〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉〈sup〉−〈/sup〉 once produced was consumed immediately, which limited the diffusion of SO〈sub〉4〈/sub〉〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉〈sup〉−〈/sup〉 out of catalyst surface and the generation of 〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉OH. The catalyst served as a surface-bound SO〈sub〉4〈/sub〉〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉〈sup〉−〈/sup〉 sink for the in-situ degradation of adsorbed BPA. Catalyst characterizations and the Density-Functional-Theory (DFT) calculation confirmed the excellent activity of CoS@GN in yielding SO〈sub〉4〈/sub〉〈sup〉〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉〈/sup〉〈sup〉−〈/sup〉 with Co(II) as the active center. A CoS@GN-coated membrane reactor was constructed to avoid catalyst loss and worked well in consecutive 3 cycles, suggesting the satisfactory catalyst reusability and system robustness. Overall, this work paved a new way for MOFs in the environmental application and provided a novel family of Co-based nanocatalysts to produce surface-bound radicals for recalcitrant contaminant degradation by SR-AOP.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309317-ga1.jpg" width="282" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): Lang Chen, Jie Tang, Lu-Na Song, Peng Chen, Jie He, Chak-Tong Au, Shuang-Feng Yin〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Oxygen-containing organics have high potentials in the synthesis of functionalized organics, and their direct generation from alcohols and alkanes by photocatalytic processes under mild conditions has aroused tremendous interest. In the past decades, much progress has been made especially in the area of heterogeneous photocatalysis under visible light irradiation. In this article, we focus on the selective oxidation of alcohols and hydrocarbons into useful oxygen-containing organics, highlighting the recent advances. Despite the achievements, scale-up production of target oxygen-containing organics is not realized due to low catalytic efficiency. The efficacy of a photocatalyst is greatly dependent on its nature, and a slight change of physicochemical properties could result in significant deviation of photocatalytic activity. For better catalyst design, the related mechanistic aspects have to be understood thoroughly. Furthermore, factors such as reactor design and reaction conditions (e.g. light region and intensity, solvent, oxidant) are critical for optimization of performance. To realize practical application in organic synthesis, it is essential to clarify the underlying mechanism. Once the parameters for optimal performance have been determined, the design of an efficient photocatalytic reactor could be properly considered.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309731-ga1.jpg" width="302" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): Zhou Chen, Tingting Fan, Mengyi Shao, Xiang Yu, Qiuling Wu, Jianhui Li, Weiping Fang, Xiaodong Yi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The graphitic carbon nitride (g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉) has emerged as one of the most promising candidates to replace the metal oxide-based catalysts for highly efficient photocatalytic materials. However, the intrinsic drawbacks of weak visible-light adsorption and poor charge separation efficiency seriously limit its practical applications. Thus, struggling controls over their structure parameters to optimize the photoelectrical properties on molecular-level for realizing highly active metal-free g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 photocatalysts have attracted a lot of focuses. Herein, a novel isopropanol assisted solvothermal-copolymerization strategy is rationally designed to synthesize a compact O, S-co-doping g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 (CNUS) with markedly reinforced π-π* and n-π* electron transitions. The meliorative structure and energy level configuration result in elevated effects for both visible-light (photon) adsorption and photo-induced carries transfer, and the CNUS exhibits outstanding photocatalytic hydrogen evolution and rhodamine B degradation performance under visible light. In addition, after continuously testing, the CNUS still shows superior stability with nearly negligible decay for both photocatalytic reactions. The characterization results indicate that the incorporated oxygen and sulfur engineer the charge, and the layered-stacking distance decreases from 0.328 to 0.322 nm, compared its counterpart (CNU prepared by direct pyrolysis of urea). Importantly, the enriched charge facilitates the rate-limiting separation of photogenerated carriers, and hence improved the visible light photocatalytic efficiency.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉An isopropanol assisted solvothermal-copolymerization strategy was used to construct a distorted C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 with enhanced visible light absorption, stronger redox ability, faster exciton dissociation efficiency, and higher photocatalytic performance.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309093-ga1.jpg" width="426" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Sheng Wang, Bicheng Zhu, Mingjin Liu, Liuyang Zhang, Jiaguo Yu, Minghua Zhou〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein, ZnO/CdS hierarchical composite was prepared through a hydrothermal and chemical bath deposition (CBD) process. Its photocatalytic H〈sub〉2〈/sub〉-production performance was tested. Mass ratio of CdS acted a pivotal part in light absorption and photocatalytic properties. Noticeably, promoted photocatalytic H〈sub〉2〈/sub〉-production activity of 4134 μmol g〈sup〉−1〈/sup〉 h〈sup〉-1〈/sup〉 was achieved by the sample with optimal CdS content. Significantly, the photoluminescence (PL) detection of hydroxyl radicals, as well as the 〈em〉in-situ〈/em〉 XPS measurements was selected to verify the direct Z-scheme charge migration mechanism. This mechanism endowed the composite with strong capability for hydrogen evolution and elucidated the improved photocatalytic performance. The improvement of photocatalytic activity was due to hierarchical structure, extended visible light response and direct Z-scheme mechanism. This work will give an innovative vision in constructing direct Z-scheme photocatalytic system with great photocatalytic H〈sub〉2〈/sub〉-production activity.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309664-ga1.jpg" width="271" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Bo Lin, Jiali Li, Baorong Xu, Xiaoqing Yan, Bolun Yang, Jinjia Wei, Guidong Yang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The relatively low charge transfer efficiency remains the critical limiting factor for the practical application of solar-driven water splitting. In this work, a promising photocatalyst intensified by dual cocatalysts was developed via separately loading Au nanoparticles and CoP nanosheets onto the inside and outside surface of three dimensionally ordered macroporous (3DOM) g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 framework to significantly facilitate the ordered transfer of charges. The spatial positioning of dual cocatalysts and average wall thickness of 3DOM g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 framework were precisely controlled to reveal the optimal distribution position of Au and CoP as well as the most appropriate transfer distance for charges (from 3DOM g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 walls to the surface of cocatalysts), respectively. The results show that the spatial positioning effect of dual cocatalysts and optimization of charge transfer distance can endow the CoP/3DOM g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Au photocatalyst with an excellent charge transfer efficiency, thereby contributing to high apparent quantum efficiency (AQE, 27.6% at 435 nm and 29.9% at 550 nm) and photocatalytic H〈sub〉2〈/sub〉 evolution activity of 11,820.1 μmol h〈sup〉−1〈/sup〉 g〈sup〉−1〈/sup〉, which is up to 619.9, 6.5 and 5.6 times than that of 3DOM g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉, CoP/3DOM g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 and 3DOM g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉/Au, respectively. This work would provide a new platform to design high-performance artificial photocatalysts with superior charge transfer capacity.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309858-ga1.jpg" width="356" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): David Ollis〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Self-cleaning photocatalytic surfaces have several decades of application, yet satisfactory rate equations for analyzing the kinetics of reactions on such solid surfaces are lacking, due in large part to the many configurations of the catalyst and the deposited contaminants.〈/p〉 〈p〉We analyze the existing literature and show that nearly all studies can be described by application of the power law for rate of reaction:〈/p〉 〈p〉Rate = k〈sub〉cat〈/sub〉 [C] 〈sup〉n〈/sup〉〈/p〉 〈p〉where n = apparent reaction order, and k〈sub〉cat〈/sub〉 is a fundamental constant of the catalytic material. The value of reaction order, n, we show requires answers to the following six questions. In each case, the observed apparent kinetic order depends upon interplay among the distributions of photocatalyst, reactant, and irradiance.〈/p〉 〈p〉1. Is the photocatalyst porous or non-porous?〈/p〉 〈p〉Example: Stearic acid on/within non-porous/porous photocatalyst layer.〈/p〉 〈p〉2. Is the photocatalytically active layer optically thin or thick?〈/p〉 〈p〉Example: Dye conversion in TiO〈sub〉2〈/sub〉 layers vs. 10% TiO〈sub〉2〈/sub〉/SiO〈sub〉2〈/sub〉?〈/p〉 〈p〉3. Is the probe reactant deposit a submonolayer or multilayer?〈/p〉 〈p〉Examples: Dye sub/multilayers with TiO〈sub〉2〈/sub〉〈/p〉 〈p〉4. Is probe reactant light absorption negligible or important?〈/p〉 〈p〉Example: Stearic acid vs. soot〈/p〉 〈p〉5. Is the probe reactant present as a continuous film or as a distribution of discrete islands?〈/p〉 〈p〉Example: Long chain carboxylic acids on TiO〈sub〉2〈/sub〉〈/p〉 〈p〉6. If distributed, what is breadth of distribution?〈/p〉 〈p〉Example: Stearic acid on TiO〈sub〉2〈/sub〉〈/p〉 〈p〉For contaminant removal we demonstrate apparent reaction orders of 0, ½, 1, and 2! Simple analysis is used to explain this diversity of apparent reaction orders. We use the six questions posed to construct a decision tree for determination of the apparent reaction order, n, as a function of responses to the six questions.〈/p〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318308178-ga1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 22 January 2017〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental〈/p〉 〈p〉Author(s): Wilm Jones, David James Martin, Angel Caravaca, Andrew M. Beale, Michael Bowker, Thomas Maschmeyer, Gareth Hartley, Anthony Masters〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Direct comparison between Pd supported on P25 TiO〈sub〉2〈/sub〉 and on C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 is made for photocatalytic hydrogen production, with UV activity being distinguished from visible light activity. Two very different, but commonly studied hole scavengers were used and compared, namely, methanol and triethanolamine (TEOA). Using full arc irradiation of a solar simulator the titania supported catalysts showed the best activity. Although with TEOA the carbon nitride supported catalyst shows some activity in visible light only, it is very small (ca. 15%) compared to that observed using the whole spectrum. When using methanol, even in the presence of UV light, the carbon nitride catalyst show only very low hydrogen yields.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337317300516-fx1.jpg" width="301" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): A. Serve, A. Boreave, B. Cartoixa, K. Pajot, P. Vernoux〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study investigates a potential synergy between Ag nanoparticles and Yttria-Stabilized Zirconia (YSZ), an oxygen ionically conducting support, for developing an efficient and stable catalyst for Diesel Particulate Filter regeneration only with oxygen. The catalytic performances as well as the mechanism for soot combustion were thoroughly analyzed through Temperature-Programmed Oxidation and isotopic experiments. We found that Ag/YSZ catalysts reach the highest activity for low contents of Ag, i.e. 2 wt%. Isotopic experiments were carefully performed to prove that active oxygen species originate from YSZ lattice. Silver was shown to promote soot oxidation activity by activating the dissociative adsorption of oxygen that can replenish the YSZ support.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318308981-ga1.jpg" width="292" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): Muhammad Shakeel, Muhammad Arif, Ghulam Yasin, Baoshan Li, Hashmat Daud Khan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The earth copious extremely active photo/electrocatalysts have been of immense interest for hydrogen evolution reaction (HER), oxygen evolution reaction (OER) together with environment purification. However, the efficiency of photo/electrocatalysis is still low because of the less visible light absorption and fast recombination of electron-hole pairs. Herein taking the benefits of layered and electronic structural design of Ni-Mn-layered double hydroxide and layered graphitic carbon nitride. A novel Ni-Mn-LDH/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 heterostructured photo/electrocatalyst with suited bands was in situ constructed by temperature controlled hydrothermal treatment. A turn in band gap energy within the range of Ni-Mn-LDH to g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 was noted through a series of physicochemical techniques. Consequently the optimized nanohybrid Ni-Mn-LDH/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 (10%) used as best electrocatalyst with 〈em〉J〈sub〉OER〈/sub〉〈/em〉 = 10 mAcm〈sup〉−2〈/sup〉 @ 316 mV and 〈em〉J〈sub〉HER〈/sub〉〈/em〉 = −60 mAcm〈sup〉−2〈/sup〉 @ −147 mV). Furthermore under visible light illumination it function as outperformed photo/electrocatalyst with 〈em〉J〈sub〉OER〈/sub〉〈/em〉 = 10 mAcm〈sup〉−2〈/sup〉 @ 296 mV and 〈em〉J〈sub〉HER〈/sub〉〈/em〉 = −60 mAcm〈sup〉−2〈/sup〉 @ −126 mV in 1 M KOH with a super stability. Similarly it was used for the degradation of RhB with outperformance (≥99%) and rate constant 〈em〉k〈/em〉 = 0.313 mn〈sup〉-1〈/sup〉. Rivaling the performance of expensive catalysts such as RuO〈sub〉2〈/sub〉 and Pt/C and other counterparts. The enhanced photo/electrocatalytic activity ascribed to the formation of band-matched layered by layered heterojunction-accelerated charge separation. It is predicted that our temperature controlled strategy based on earth-profuse elements with structural reliability providing an innovative and inexpensive photo/electrocatalytic system for realistic energy conversion applications.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Graphical illustration of photo/electrocatalytic activities of the layered by layered Ni-Mn-LDH/g-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 nanohybrid.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309536-ga1.jpg" width="235" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): Xiangju Ye, Yinghao Chen, Yahui Wu, Xuemei Zhang, Xuchun Wang, Shifu Chen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In a reaction system, the simultaneously efficient utilization of photogenerated electrons and holes to realize the photocatalytic selective redox reactions of organics has been a hot topic. In this paper, the Zn〈sub〉3〈/sub〉In〈sub〉2〈/sub〉S〈sub〉6〈/sub〉 samples were synthesized 〈em〉via〈/em〉 a simple solvothermal method with different solvents, which could make full use of photogenerated electrons and holes to achieve the photocatalytic selective transformation of aromatic alcohols to aromatic aldehydes and hydrogen evolution under mild conditions. The results show that the Zn〈sub〉3〈/sub〉In〈sub〉2〈/sub〉S〈sub〉6〈/sub〉 synthesized with water (Zn〈sub〉3〈/sub〉In〈sub〉2〈/sub〉S〈sub〉6〈/sub〉-W) exhibits the highest photocatalytic performance among the selected samples, with which the yields of benzaldehyde and hydrogen reach up to 732 and 708.8 μmol under light irradiation (λ ≥ 380 nm) for 4 h, respectively. The molar ratios between aldehydes and hydrogen are close to 1: 1. The apparent quantum efficiency is about 6.48% for wavelength λ = 380 ± 10 nm over Zn〈sub〉3〈/sub〉In〈sub〉2〈/sub〉S〈sub〉6〈/sub〉-W sample. A possible reaction mechanism for the photocatalytic selective transformation of benzyl alcohol to benzaldehyde and hydrogen evolution under light irradiation is proposed. This work highlights that a reaction system is developed to effectively make use of the photogenerated electrons and holes for selective transformation of aromatic alcohols to aromatic aldehydes and hydrogen evolution over Zn〈sub〉3〈/sub〉In〈sub〉2〈/sub〉S〈sub〉6〈/sub〉 photocatalysts under mild conditions.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309524-ga1.jpg" width="217" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): Imme Kretschmer, Alejandro M. Senn, J. Martín Meichtry, Graciela Custo, Emilia B. Halac, Ralf Dillert, Detlef W. Bahnemann, Marta I. Litter〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hematite nanoparticles (〈em〉n〈/em〉Hm) were tested for Cr(VI) photocatalytic reduction (300 μM) in the presence of different electron donors such as citrate (Cit), oxalate (Ox), 2-propanol and methanol. At pH 3 and under irradiation at 〈em〉λ〈/em〉 ≥ 310 nm, almost negligible reaction took place in the absence of donor or with the alcohols, while the reduction was very rapid in the presence of Cit (less than 25 min), and faster with Ox (15 min). Homogeneous experiments with FeCl〈sub〉3〈/sub〉 instead of 〈em〉n〈/em〉Hm showed a complete Cr(VI) reduction in the presence of both complexing agents in less than 10 min. Under irradiation at 〈em〉λ〈/em〉 〉 495 nm and with 〈em〉n〈/em〉Hm at pH 3, a good Cr(VI) transformation took place with both donors, but at a considerably lower rate than under UV light (around 100% at 180 min), the decay being negligible in the homogeneous systems with Fe(III). Under irradiation at 〈em〉λ〈/em〉 〉 610 nm, no Cr(VI) transformation took place over 〈em〉n〈/em〉Hm. Experiments at pH 6 under UV–Vis light with Cit in the presence of 〈em〉n〈/em〉Hm gave a good Cr(VI) decay, faster with Fe(III) (60% and 90% in 105 min, respectively); some Cr(VI) transformation (around 35% in 180 min) was found with Cit under Vis light. Interestingly, at both wavelength ranges, the reaction was negligible when Ox was used. Mechanisms taking place under the different conditions were proposed, including the role of surface charge transfer complexes on 〈em〉n〈/em〉Hm.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318308889-ga1.jpg" width="211" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): Zizheng Ai, Yongliang Shao, Bin Chang, Baibiao Huang, Yongzhong Wu, Xiaopeng Hao〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Spontaneous photocatalytic H〈sub〉2〈/sub〉 evolution from solar-driven water splitting is highly attractive for converting abundant solar energy to valuable fuel. Regulation of the direction of photocarriers separation and transport is an important factor influencing solar energy conversion efficiency. Here, structural design and energy band engineering are employed to design and construct a novel Ti〈sub〉3〈/sub〉C〈sub〉2〈/sub〉(TiO〈sub〉2〈/sub〉)@CdS/MoS〈sub〉2〈/sub〉 composite photocatalyst. The transfer direction of photogenerated electrons and holes is achieved via rational conjunction of Ti〈sub〉3〈/sub〉C〈sub〉2〈/sub〉 and MoS〈sub〉2〈/sub〉. This well designed photocatalytic system possesses remarkable H〈sub〉2〈/sub〉 evolution rate (8.47 mmol h〈sup〉−1〈/sup〉 g〈sup〉−1〈/sup〉) and excellent photocatalytic stability. Furthermore, a high H〈sub〉2〈/sub〉 yield rate of 344.74 μmol h〈sup〉−1〈/sup〉 g〈sup〉−1〈/sup〉 can be reached in pure water without any electron sacrificial agents. Through combination with the scope of a type II junction between CdS and MoS〈sub〉2〈/sub〉, the new Z-scheme between CdS and TiO〈sub〉2〈/sub〉 transformed from Ti〈sub〉3〈/sub〉C〈sub〉2〈/sub〉 sets up a multi-step separation of electron-hole pairs. This process prolongs the lifetime of photogenerated electrons and makes them reach the active sites to initiate an efficient photocatalytic redox reaction. This work demonstrates that the design philosophy of selectively controlling the transfer direction of electrons and holes has promising applications in solar energyutilisation.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309445-ga1.jpg" width="390" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): Piyong Zhang, Gongchang Zeng, Ting Song, Shaobin Huang, Tingting Wang, Heping Zeng〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Solar-driven hydrogen evolution with sustainable energy sources, which require earth-abundant, robust and efficient photocatalysts for fuel production, is highly desirable. Here, we propose an alternative promising configuration of a dendrite-like plasmonic CuCo bimetal as a nonsemiconductor photocatalyst, which exhibits exceptional photocatalytic activities for H〈sub〉2〈/sub〉 evolution (77.1 μmol g〈sup〉−1〈/sup〉 h〈sup〉−1〈/sup〉) under sunlight irradiation without a sacrificial agent. Notably, a certain amount of hydrogen evolved by photocatalytic water splitting was conserved by the photocatalyst at room temperature, demonstrating that the integration of hydrogen evolution and storage was realized in this device. Electrons were produced by the surface plasmon resonance (SPR) effect of the Cu component in CuCo bimetal, and Co nanosheets were grown in situ on the surface of Cu, which can facilitate the transfer of photoinduced charge as a cocatalyst. Specifically, the photocatalyst shows excellent chemical stability with X-ray photoelectron spectroscopy and X-ray diffraction characterization after four consecutive cycles over a total of 20 h. This work provides insights into a plasmonic nonsemiconductor photocatalytic system in the hydrogen energy field.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309706-ga1.jpg" width="249" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Andrea Giampiccolo, David Maria Tobaldi, Salvatore Gianluca Leonardi, Billy James Murdoch, Maria Paula Seabra, Martin P. Ansell, Giovanni Neri, Richard J. Ball〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Human exposure to volatile organic compounds and NO〈sub〉2〈/sub〉 can lead to health problems, therefore strategies to mitigate against the risks are required. Abatement and sensing are approaches which could both neutralise and monitor these species thus providing a safer environment and warning occupants of harmful levels. This paper presents pure TiO〈sub〉2〈/sub〉 and TiO〈sub〉2〈/sub〉/graphene hybrids synthesized through a sol-gel route. Electron optical, helium ion microscopy, X-ray diffraction and spectroscopic methods have been applied to elucidate the physical and chemical behaviour. NO〈sub〉2〈/sub〉 sensing properties of TiO〈sub〉2〈/sub〉/graphene hybrids formed by the addition of graphene to the reaction vessel prior to initiating the sol gel reaction followed by annealing (〈strong〉GTiO〈sub〉2〈/sub〉S),〈/strong〉 and an alternative manufacturing method involving the addition of graphene to TiO〈sub〉2〈/sub〉 nanoparticles which had already been annealed (〈strong〉GTiO〈sub〉2〈/sub〉M〈/strong〉) were compared and evaluated. A conductometric sensor based on TiO〈sub〉2〈/sub〉/graphene prepared using material 〈strong〉GTiO〈sub〉2〈/sub〉S〈/strong〉 showed a higher response to NO〈sub〉2〈/sub〉 compared to sensors based on pure TiO〈sub〉2〈/sub〉 and TiO〈sub〉2〈/sub〉/graphene prepared with material 〈strong〉GTiO〈sub〉2〈/sub〉M〈/strong〉. Under UV irradiation generated by a low power LED, the sensor showed a remarkably enhanced response to 1750 ppb NO〈sub〉2〈/sub〉, about double the response in the dark, and a limit of detection of about 50 ppb of NO〈sub〉2〈/sub〉 (Signal/Noise = 3). Photocatalytic tests to assess the degradation of NO〈sub〉x〈/sub〉 showed that TiO〈sub〉2〈/sub〉/graphene hybrids using material 〈strong〉GTiO〈sub〉2〈/sub〉S〈/strong〉 were the most active amongst the whole series of TiO〈sub〉2〈/sub〉-based materials. Our data highlights the unique characteristics of material 〈strong〉GTiO〈sub〉2〈/sub〉S〈/strong〉 TiO〈sub〉2〈/sub〉/graphene and the suitability for multi-purpose applications in the field of environmental monitoring and remediation. The capability of the material for both sensing and abatement of NO〈sub〉x〈/sub〉 could be exploited to offer a safer environment through providing a warning of the presence of NO〈sub〉x〈/sub〉 whilst also reducing levels.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309883-ga1.jpg" width="488" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): S. Ullah, E.P. Ferreira-Neto, C. Hazra, R. Parveen, H.D. Rojas-Mantilla, M.L. Calegaro, Y.E. Serge-Correales, U.P. Rodrigues-Filho, S.J.L. Ribeiro〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The development of photocatalysts responsive towards a broader region of the solar (UV-to-NIR) light is important for efficient harvesting of sunlight for photochemical and photoelectrical applications. In this study, two photocatalytic systems (BV/LEDs and BV/UCPs where UCPs stands for NaYbF〈sub〉4〈/sub〉:Tm〈sup〉3+〈/sup〉 upconversion particles) based on bismuth vanadate (BV) are introduced for photocatalytic degradation of both organic dyes (crystal violet, CV) and pharmaceuticals (sulfathiazole, STZ) under a variety of photoactivation modes including low-power (1.26 W) LEDs and near infrared (NIR) irradiation as well as natural sunlight. The BV/LEDs system makes use of the perfect match between the emission profile of commercial blue LEDs (460 ± 10 nm) and absorption profile of BV (E〈sub〉g〈/sub〉 = 2.6 eV) to effectively photodegrade pollutants. The BV/UCPs system, on the other hand, exploits the NIR-to-UV/visible upconverted light from UCPs to allow photodegradation of pollutants under NIR illumination. Moreover, we present a detailed study of the experimental parameters to obtain BV particles with tailored morphology (spherical, rod-like, hyperbranched), crystalline phase (monoclinic, tetragonal or heterojunction biphasic BV) and band gap energy (2.4–2.9 eV). Depending on the phase composition, a synergetic effect in photoactivity is observed in samples containing around 68% monoclinic and 30% tetragonal BV which is ascribed to the formation of monoclinic/tetragonal heterojunction.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉A photocatalytic system based on bismuth vanadate (BV) and BV coupled with NIR-to-UV/visible NaYbF〈sub〉4〈/sub〉:Tm〈sup〉3+〈/sup〉 upconversion particles (BV/UCPs) is proposed for photocatalytic degradation of pollutants (dyes, pharmaceuticals) under a variety of photoactivation modes including natural sunlight, blue LEDs and near infrared (NIR) irradiation.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309342-ga1.jpg" width="266" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Junqiu Guo, Xin Liao, Ming-Hsien Lee, Geoff Hyett, Chung-Che Huang, Daniel W. Hewak, Sakellaris Mailis, Wei Zhou, Zheng Jiang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Synergetic experimental and DFT insights of energy band structures and photogenerated rate-limiting reactive species are indispensable to design impurity-doped photocatalysts for photocatalytic environment remediation and solar fuels. Herein, despite the larger bandgap (Eg) of the Zn-doped BiOBr samples, they exhibited superior activity to BiOBr in the photocatalytic water splitting but impaired the photodegradation of Rhodamine B under visible-light illumination. Based on the spectral and electrochemical impedance characterisations and DFT simulations, the wider bandgaps of Zn-doped BiOBr samples were explicitly assigned to the more positive valence band maxima (VBM) and more negative conduction band minima (CBM). The enhanced photocatalytic water splitting on the Zn-doped BiOBr was arisen from the higher redox chemical potentials of charge carriers on respective CBM and VBM, suppressed back reactions and depressed recombination of photogenerated charge carriers. However, the reduced e〈sup〉−〈/sup〉-h〈sup〉+〈/sup〉 recombination on the Zn-doped BiOBr cannot cancel the detrimental influences from the weaker light absorption and dye-sensitisation effects, leading to slower RhB photodegradation.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉The effects of Zn-doping on the band structures and visible-light-driven photocatalytic RhB degradation and water splitting were defined via spectral, DFT and photoelectrochemical characterisations.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309329-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): Jingsha Li, Jiajie Chen, Hao Wan, Jin Xiao, Yougen Tang, Min Liu, Haiyan Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Iron and nitrogen co-doped carbon materials (Fe-N-C) have been widely investigated as one of the most promising electrocatalysts with low cost and excellent catalytic activity towards oxygen reduction reaction (ORR). Herein, inspired by the cytochrome c oxidase (CcO), we have proposed a high-performance bimetal Cu/Fe-regulating nitrogen-doped carbon (Cu-Fe-N-C) electrocatalyst via using partial copper substitution to iron in Fe-N-C. The optimized Cu-Fe-N-C composite displays much better catalytic activity than the pristine Fe-N-C indicated by 20 mV positive shift of onset potential (0.967 V vs RHE), 25 mV positive shift of half-wave potential (0.864 V vs RHE) and higher limiting-current density. The significantly enhanced performance is also manifested by a higher discharging cell voltage and better stability in practical Al-air batteries at a constant current density. Both experimental and computational results confirm that the significantly enhanced performance should be mainly ascribed to the synergistic effects of the bimetallic doping in Cu-Fe-N-C catalysts.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318308737-ga1.jpg" width="253" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): Yeasin Khan, Cheong Il Chung, Jin Joo Oh, Thanh Tung Nguyen, Hye Jin Lee, Minserk Cheong, Bright Walker, Hoon Sik Kim, Yong Jin Kim〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The oxidative carbonylation of alcohols to prepare corresponding dialkyl carbonates was investigated using alkali metal methylselenite [MSeO〈sub〉2〈/sub〉(OCH〈sub〉3〈/sub〉)] and alkali metal selenites (M〈sub〉2〈/sub〉SeO〈sub〉3〈/sub〉, M = Li, Na, K, Cs) as catalysts. Of various alcohols tested, methanol and 2-methoxyethanol (MEG) are found to be highly reactive, affording corresponding dialkyl carbonates in yields of more than 30%, which are significantly higher than those achieved with Cu-based catalysts under similar reaction conditions. XRD and GC-Mass analysis of the spent catalyst recovered from the M〈sub〉2〈/sub〉SeO〈sub〉3〈/sub〉-catalyzed reaction of methanol revealed that M〈sub〉2〈/sub〉SeO〈sub〉3〈/sub〉 was converted into elemental selenium and MHCO〈sub〉3〈/sub〉 along with the formation of several selenium-containing by-products including malodorous dimethyldiselenide, 1,2-dimethoxydiselane, and O,Se-dimethyl carbonoselenoate. On the contrary, the oxidative carbonylation of MEG with K〈sub〉2〈/sub〉SeO〈sub〉3〈/sub〉 was highly selective toward the formation of bis(2-methoxyethyl) carbonate (BMEC), without producing any selenium-containing by-products. A plausible mechanism for the MSeO〈sub〉2〈/sub〉(OCH〈sub〉3〈/sub〉)- and M〈sub〉2〈/sub〉SeO〈sub〉3〈/sub〉-catalyzed oxidative carbonylation of MEG was suggested on the basis of mechanistic and experimental results.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉K〈sub〉2〈/sub〉SeO〈sub〉3〈/sub〉 was highly active, stable, and recyclable for the synthesis of bis(2-methoxyethyl) carbonate (BMEC) from the oxidative carbonylation of 2-methoxyethanol (MEG), but turned out to be unsuitable for the carbonylation of methanol, transforming into inactive and stinky selenium-containing compounds such as (CH〈sub〉3〈/sub〉Se)〈sub〉2〈/sub〉, CH〈sub〉3〈/sub〉SeCO〈sub〉2〈/sub〉CH〈sub〉3〈/sub〉, and (CH〈sub〉3〈/sub〉OSe)〈sub〉2〈/sub〉.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309822-ga1.jpg" width="209" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): Xiaoxue Hou, Kai Zhao, Olga A. Marina, M. Grant Norton, Su Ha〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A multi-functional NiMo-ceria-zirconia composite was developed as an anode for a solid oxide fuel cell (SOFC) running on isooctane, a commonly used gasoline surrogate. The anode layer was fabricated on an electrolyte-supported single cell using yttria-stabilized zirconia (YSZ) as the electrolyte and La〈sub〉0.6〈/sub〉Sr〈sub〉0.4〈/sub〉Co〈sub〉0.2〈/sub〉Fe〈sub〉0.8〈/sub〉O〈sub〉3-δ〈/sub〉 as the cathode. Our results indicate that the single NiMo-ceria-zirconia layer possesses a dual-functionality: firstly to internally convert complex hydrocarbons into synthesis gas with a high resistance to coking and secondly to electrochemically oxidize the synthesis gas mixture for electric power generation. Compared with the conventional Ni-YSZ anode single cell, the application of the ceria-zirconia in the anode significantly suppresses carbon deposition and improves the performance stability of the single cell. Furthermore, the addition of Mo in the Ni-ceria-zirconia appears to facilitate a higher degree of sintering for the anode, which increases the electronic conductivity and maximum power density of the single cell. Consequently, at 800 °C the single cell with 5 wt.% Mo in the Ni-ceria-zirconia-based anode displayed a higher maximum power density of 212 mW cm〈sup〉−2〈/sup〉 at 0.48 V and significantly enhanced performance stability than the conventional Ni-YSZ anode single cell in the isooctane/air operating mode.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092633731830938X-ga1.jpg" width="382" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 242〈/p〉 〈p〉Author(s): Yi Liu, Yuliu Liu, Yi Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Aqueous-phase hydrogenation of glucose to lower diols (ethylene glycol (EG), 1, 2-propylene glycol (PG), and butanediol (BDO)) over bi-functional Ru-W supported catalysts was investigated in a continuous-flow fixed-bed reactor. A variety of catalysts based on different supports including mesoporous SiO〈sub〉2〈/sub〉, activated carbon (AC), carbon nanofibers (CNFs), and bulk WO〈sub〉3〈/sub〉 were compared and examined by N〈sub〉2〈/sub〉 physisorption, H〈sub〉2〈/sub〉 chemisorption, XRD, TEM, ICP, H〈sub〉2〈/sub〉-TPR, 〈em〉in-situ〈/em〉/〈em〉ex-situ〈/em〉 XPS, NH〈sub〉3〈/sub〉-TPD, and Raman spectra. The results indicate that the lower diols yield is highly dependent on the synergistic effect of Ru metal sites and WO〈sub〉x〈/sub〉 acid sites, in other words, strongly depending on the competitive reactions of the glucose. Abundant W〈sup〉4+〈/sup〉 and Ru° sites on Ru-W/SiO〈sub〉2〈/sub〉 catalysts with large specific surface area effectively catalyze the selective cleavage of the C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉C bonds in glucose and subsequent hydrogenation to lower diols, resulting in 100% glucose conversion as well as highest diols selectivity (87.3%) over 50 h reaction at 478 K and 4 MPa H〈sub〉2〈/sub〉. Meanwhile, the Ru/WO〈sub〉3〈/sub〉 with much lower surface area forms more W〈sup〉5+〈/sup〉 species, which is advantageous to producing more EG products (55.9%) at the same reaction conditions.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉A highly efficient and stable catalytic hydrogenolysis of glucose to lower diols has been developed in a continuous-flow fixed-bed reactor over Ru-W based bi-functional catalyst.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318309263-ga1.jpg" width="404" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Jungkuk Lee, Joseph R. Theis, Eleni A. Kyriakidou〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The modern three-way catalyst (TWC) is very effective for treating the hydrocarbons (HCs), carbon monoxide (CO), and nitrogen oxides (NOx) from stoichiometric gasoline engines once the TWC has achieved its minimum operating temperature (e.g., 250 to 400 °C, depending on the gas species). Likewise, the diesel oxidation catalyst (DOC), selective catalytic reduction (SCR) catalyst with urea injection, and the diesel particulate filter (DPF) are effective for treating the HCs, CO, NOx, and particulate matter (PM) emissions from diesel engines once the catalysts are warmed up, although this can require a significant length of time (e.g., 1 to 3 min) because of the relatively low exhaust temperatures from diesel engines. For both types of engines, excess fueling is often used to accelerate the heating of the catalyst system after a cold start, although this decreases the fuel economy of the vehicle. Even with excess fueling, a high portion (up to 80%) of the total vehicle emissions is emitted during the cold start period (i.e., the period before the catalysts are functional). To treat the HC emissions during this cold start period, one approach is to employ a HC trap (HCT) that can adsorb the HC emissions at low temperatures and then oxidize the stored HCs to carbon dioxide (CO〈sub〉2〈/sub〉) and water (H〈sub〉2〈/sub〉O) at higher temperatures. To treat the NOx emissions during the cold start period, a passive NOx adsorber (PNA) can adsorb the NOx at low temperatures. For stoichiometric gasoline applications, the PNA can then reduce the stored NOx to nitrogen (N〈sub〉2〈/sub〉) at higher temperatures. On diesel engines, the PNA can release the stored NOx back into the exhaust once the downstream urea/SCR system is operational. Some adsorber technologies have the capability of adsorbing HCs and NOx simultaneously. In this review, the HC trapping and passive NOx adsorbing technologies will be discussed in separate sections. This review will describe how the current trapping technologies can be applied in vehicle exhaust systems, the material properties required for efficient HCTs and PNAs, and the exhaust conditions that can inhibit/enhance their trapping properties. First, the performance of HCTs will be discussed in terms of their physical properties (e.g., pore size, acidity, presence of metal ions) and the trapping conditions (e.g., storage temperature, space velocity, and the presence of other exhaust species such as H〈sub〉2〈/sub〉O and CO〈sub〉2〈/sub〉). This will be followed by in-depth coverage of the reactions occurring during HC desorption. The second part of this review will focus on the composition of various PNA formulations, the effects of the trapping conditions (e.g., temperature, space velocity, the presence of other exhaust species such as CO〈sub〉2〈/sub〉, H〈sub〉2〈/sub〉O, CO, and C〈sub〉2〈/sub〉H〈sub〉4〈/sub〉), and the effects of sulfur poisoning on their trapping performance. The effect of hydrothermal aging and the regenerability of HCTs and PNAs will also be discussed. A significant amount of literature has emerged recently regarding HCTs and PNAs; this review is primarily focused on summarizing this literature and reconciling the differences presented.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318310403-ga1.jpg" width="497" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Catalysis B: Environmental, Volume 243〈/p〉 〈p〉Author(s): Shangcong Sun, Yong-Chao Zhang, Guoqiang Shen, Yutong Wang, Xianlong Liu, Zhenwei Duan, Lun Pan, Xiangwen Zhang, Ji-Jun Zou〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Photocatalytic overall water splitting is one of the ultimate goals in solar conversion and the activation and cleavage of H〈sub〉2〈/sub〉O molecule is the initial and often rate-determining step in this reaction. Through DFT calculations, we designed Pt cluster decorated Ni(OH)〈sub〉2〈/sub〉 nanoparticles (Pt/Ni(OH)〈sub〉2〈/sub〉) as robust cocatalyst capable of activating H〈sub〉2〈/sub〉O and dissociating HO〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉H bonds. Then the unique structure was fabricated through in-situ photo-oxidation of Ni〈sub〉2〈/sub〉P to Ni(OH)〈sub〉2〈/sub〉 on semiconductor like C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 and subsequent selective photo-deposition of Pt on Ni(OH)〈sub〉2〈/sub〉 surface. Pt/Ni(OH)〈sub〉2〈/sub〉-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 is much more active in photocatalytic HER, OER and overall water splitting compared with Pt, Ni(OH)〈sub〉2〈/sub〉 and spatially separated co-loaded Ni(OH)〈sub〉2〈/sub〉-Pt on C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉. And Pt/Ni(OH)〈sub〉2〈/sub〉-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 achieves an AQE of 1.8% at 420 nm in overall water splitting by using only 0.3 wt% Pt, superior to most solid-state photocatalytic systems to date. Moreover, Pt/Ni(OH)〈sub〉2〈/sub〉 composite enables TiO〈sub〉2〈/sub〉 to split pure water in good stoichiometry. This work emphasizes the importance of H〈sub〉2〈/sub〉O activation and may pave the way for enabling single semiconductors to efficiently split pure water.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0926337318310075-ga1.jpg" width="251" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉