Evidence for low-temperature oxygen migration from ceria to Rh

Journal Article · Mon Feb 01 04:00:00 EST 1993 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1993.1049· OSTI ID:6260014

Zafiris, G S; Gorte, R J ^[1]

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

The authors have examined the structure and adsorption properties Rh deposited on amorphous ceria films in ultrahigh vacuum. Following adsorption of CO on Rh/ceria, a significant fraction of the CO reacts to CO[sub 2] during temperature-programmed desorption (TPD), even for relatively large Rh particles. The extra oxygen is shown to come from the ceria, since the near-surface region can be depleted by multiple adsorption-desorption cycles and since additional oxygen can be brought out from the bulk ceria by high-temperature annealing. The adsorption of NO on Rh/ceria is also affected in ways that suggest that the oxygen is migrating to the surface of the Rh near room temperature. These results have important implications on the catalytic properties of Rh/ceria catalysts and help to explain the high activity of these catalysts for the water-gas-shift reaction. 25 refs., 5 figs.

• OSTI ID: 6260014
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 139:2; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ANNEALING
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYSIS
CATALYST SUPPORTS
CATALYSTS
CATALYTIC EFFECTS
CERIUM COMPOUNDS
CERIUM OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISORPTION
DESORPTION
ELEMENTS
FILMS
FLUIDS
FUEL GAS
FUELS
GAS FUELS
GASES
HEAT TREATMENTS
INTERMEDIATE BTU GAS
MIGRATION
NITRIC OXIDE
NITROGEN COMPOUNDS
NITROGEN OXIDES
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PARTICLES
RARE EARTH COMPOUNDS
REFRACTORY METAL COMPOUNDS
RHODIUM COMPOUNDS
SEPARATION PROCESSES
SORPTION
SORPTIVE PROPERTIES
SURFACE PROPERTIES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0400-1000 K
TRANSITION ELEMENT COMPOUNDS
WATER GAS
WATER GAS PROCESSES