Total Oxidation of Carbon Monoxide and Methane over Transition Metal-Fluorite Oxide Composite Catalysts. II. Catalyst Characterization and Reaction Kinetics

Article abstract of DOI:10.1006/jcat.1995.1133

Cu-Ce-O and Au-Ce-O catalysts were characterized by XRD, XPS, and STEM.Copper in small amounts showed a strong tendency to associate with cerium oxide.When the cerium oxide surface was saturated with copper, excess copper formed bulk copper oxide particles.The cuprous(+1) oxidation state was identified by XPS for the copper clusters distributed in cerium oxide, while gold in the Au-Ce-O catalyst was in the form of metallic particles distributed in the cerium oxide matrix.The reaction kinetics of CO and methane oxidation over the Cu-Ce-O catalysts were measured at a partial pressure of CO or oxygen from 0.001 to 0.06 bar, at a partial pressure of methane from 0.001 to 0.03 bar, and at temperatures ranging from 40 t0 200 deg C for CO oxidation and from 400 to 550 deg C for methane oxidation.The oxidation rates of CO and methane over the Cu-Ce-O catalysts were expressed as kK_RP_RP_Oⁿ/(1+K_RP_R), where P_R denotes the partial pressure of CO or methane and P_O is the partial pressure of oxygen.CO oxidation kinetics over the Au-Ce-O catalyst were described by kP_CO^0.3P_O^0.18.The kinetic results were interpreted with the Langmuir-Hinshelwood mechanism and in terms of a synergistic effect resulting from the interaction of the two kinds of materials.

Full text of DOI:10.1006/jcat.1995.1133

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Evaluation Only. Created with Aspose.PDF. Copyright 2002-2021 Aspose Pty Ltd.