Total oxidation of carbon monoxide and methane over transition metal-fluorite oxide composite catalysts. II. Catalyst characterization and reaction kinetics
- Tufts Univ., Medford, MA (United States)
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 to 100{degrees}C for CO oxidation and from 400 to 550{degrees}C for methane oxidation. The oxidation rates of CO and methane over the Cu-Ce-O catalysts were expressed as kK{sub R}P{sub R}P{sup n}{sub o}/(1 + K{sub R}P{sub R}), where P{sub R} denotes the partial pressure of oxygen. CO oxidation kinetics over the Au-Ce-O catalyst were described by kP{sup 0.3}{sub CO}P{sup 0.18}{sub O}. 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. 44 refs., 13 figs., 2 tabs.
- DOE Contract Number:
- FG22-92PC92534
- OSTI ID:
- 101904
- Journal Information:
- Journal of Catalysis, Journal Name: Journal of Catalysis Journal Issue: 2 Vol. 153; ISSN JCTLA5; ISSN 0021-9517
- Country of Publication:
- United States
- Language:
- English
Similar Records
Selective catalytic reduction of sulfur dioxide to elemental sulfur. Final report
Effects of cerium addition on CO oxidation kinetics over alumina-supported rhodium catalysts