A study of CO oxidation kinetics on Rh/ceria

Journal Article · Wed Nov 01 04:00:00 UTC 1995 · Journal of Catalysis

DOI:https://doi.org/10.1006/jcat.1995.1282· OSTI ID:183489

Bunluesin, T; Cordatos, H; Gorte, R J ^[1]

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1. Univ. of Pennsylvania, Philadelphia, PA (United States)

CO oxidation kinetics, at differential conversions, have been studied on model Rh/ceria catalysts over a wide pressure and temperature range to investigate the effect of ceria support interactions with Rh on the catalystic properties. The kinetics suggest that there are two reaction mechanisms in excess CO. The first is identical to that reported for pure Rh and exhibits a reaction order of {approximately} 1 for O{sub 2} and - 1 for CO, with an activation energy between 25 and 27 kcal/mol. The second mechanism is 0.4 order in O{sub 2} and zeroth order in CO, with a much lower activation energy, between 12 and 15 kcal/mol. This second reaction, which becomes more important for smaller Rh particle sizes, high CO pressures, and low temperatures, appears to involve reaction of oxygen from the ceria with CO from Rh. Possible implications of these results for catalytic performance are discussed. 22 refs., 4 figs.

• OSTI ID: 183489
• Journal Information: Journal of Catalysis, Journal Name: Journal of Catalysis Journal Issue: 1 Vol. 157; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
40 CHEMISTRY
ACTIVATION ENERGY
CARBON MONOXIDE
CATALYTIC EFFECTS
CERIUM OXIDES
CHEMICAL REACTION KINETICS
HETEROGENEOUS CATALYSIS
OXIDATION
RHODIUM