Effects of cerium addition on CO oxidation kinetics over alumina-supported rhodium catalysts

Journal Article · Mon Aug 01 00:00:00 EDT 1988 · Journal of Catalysis; (USA)

DOI:https://doi.org/10.1016/0021-9517(88)90169-8· OSTI ID:6555658

Oh, Se H; Eickel, C C ^[1]

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1. General Motors Research Labs., Warren, MI (USA)

The kinetics of CO oxidation in a strongly oxidizing environment (i.e., P{sub O{sub 2}} {much gt} P{sub CO}) over a low-loaded Rh/Al{sub 2}O{sub 3} catalyst are not significantly affected by the presence of cerium. Under moderately oxidizing or net-reducing conditions, on the other hand, the addition of sufficient amounts of cerum oxides ({ge}2 wt% Ce) to the Rh/Al{sub 2}O{sub 3} catalysts was found to cause the following changes in CO oxidation kinetics: suppression of the CO inhibition effect, decreased sensitivity of the reaction rate to gas-phase O{sub 2} concentration, and decreased apparent activation energy. These cerium-induced changes in the kinetics lead to enhancement of CO oxidation activity and can be rationalized on the basis of a mechanism involving CO{sub 2} formation via a reaction between CO adsorbed on Rh and surface oxygen derived from the neighboring ceria particles. The effects of Ce addition on the CO oxidation kinetics were also independent of whether the Ce was deposited before or after the Rh.

• OSTI ID: 6555658
• Journal Information: Journal of Catalysis; (USA), Journal Name: Journal of Catalysis; (USA) Vol. 112:2; ISSN 0021-9517; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330702* -- Emission Control-- Carbon Monoxide
ACTIVATION ENERGY
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON MONOXIDE
CARBON OXIDES
CATALYSIS
CATALYST SUPPORTS
CATALYSTS
CATALYTIC CONVERTERS
CATALYTIC EFFECTS
CERIUM
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
ELEMENTS
ENERGY
EQUIPMENT
EXHAUST GASES
FLUIDS
GASEOUS WASTES
GASES
INHIBITION
KINETICS
METALS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
POLLUTION CONTROL EQUIPMENT
QUANTITY RATIO
RARE EARTHS
REACTION KINETICS
RHODIUM
SYNTHESIS
TRANSITION ELEMENTS
WASTES