ISSN:
1662-9779
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Physics
Notes:
Silica supported nickel molybdenum phosphides (NiMoP/SiO2) were successfullyprepared by temperature-programmed reduction (TPR) reaction of phosphorous-impregnated nickelmolybdenum oxides (NiMoO4) precursors with hydrogen at relatively low temperatures (530 – 590oC) and characterized by Fourier transform-Infrared spectrometry (FT-IR), X-ray diffraction (XRD),Electron probe microanalysis (EPMA) and Temperature-programmed reduction reaction (TPR). Theprocess of solid transformation and properties of materials prepared from ammonium hydrogenphosphate (AMP)-impregnated samples were compared with those of phosphide made fromphosphoric acid (PAC)-impregnated samples. Results show that the formation of a single NiMoPphase on silica significantly depends on reduction rates, phosphorous sources and phosphorousloadings. A single phase of NiMoP on SiO2 was particularly promoted at a below 5 oC/min ofreduction rate and the starting molar ratio of Ni/Mo/P=1/1/1. A single phase of crystalline NiMoPon silica was produced from AMP-impregnated samples, while other phases of MoP, Ni2P, orNiMoP2 were appeared from PAC-impregnated samples with loading. The new phase of NiMoP2was occurred with increasing phosphorous loading (above Ni/Mo/P=1/1/2.5) as a result offacilitated contact on the surface between the Ni-Mo bimetallic component and the phosphorousreagent
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/24/transtech_doi~10.4028%252Fwww.scientific.net%252FSSP.124-126.1765.pdf
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