ISSN:
1572-9028
Keywords:
CO oxidation
;
PdOx/MnO2
;
redox properties
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract PdOx/MnO2 has been examined as a catalyst for CO oxidation using a conventional flow reactor at reaction temperatures between 50 and 150°C. In the reaction conditions of GHSV (gas‐hourly‐space‐velocity) of 1.22 × 105/h and CO concentration of 2000 ppm, PdOx/MnO2 showed higher catalytic activity compared with PdOx/Mn2O3, which had been previously reported as an effective catalyst due to the cooperative action of Pd and Mn2O3 for this reaction. The reason for higher activity of PdOx/MnO2 than PdOx/Mn2O3 has been investigated using TPR (temperature‐programmed reduction) and XPS studies. TPR showed that PdOx/MnO2 could be reduced by CO at much lower temperature than PdOx/Mn2O3. During the experiment of reduction and oxidation, XPS showed that the valence of Mn in the PdOx/MnO2 was between 4+ and 3+, which is higher than that of Mn in the PdOx/Mn2O3 catalyst of which the valence has been reported to be between 3+ and 2+. It is known that in this catalyst system the support supplies oxygen onto Pd, where the oxidation occurs with adsorbed CO, and the ability of the support to provide oxygen improves the performance of the catalyst. Therefore, it was concluded that the readiness of MnO2 to be reduced with maintaining a higher oxidation state showed higher CO oxidation activity than Mn2O3 as support for PdOx.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1019124419791
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