Comparative study of alumina-supported CuO and CuCr/sub 2/O/sub 4/ as catalysts for CO oxidation
Alumina-supported CuO and CuCr/sub 2/O/sub 4/ catalysts of various compositions were prepared and their activity for CO oxidation measured. Fresh, pretreated with CO, and reoxidized catalysts were studied. In general, the activity increased with the CO pretreatment. The extent of the activation depended on the catalyst composition. Thus, copper catalysts were more active than copper chromite at low metal concentrations (< 12 wt%), but the opposite was observed at concentrations higher than about 12 wt%. The results on activity behavior, together with TPR and XRD spectra, suggest that the active species are related to copper cations. In the low concentration copper catalysts, the most active surface is generated after CO pretreatment, followed by a fast reoxidation occurring at the first stages of the reaction. In the high concentration copper catalysts, the CO pretreatment produced an induction period as a result of excessive reduction. It is suggested that the role of chromium is to limit the extent of reduction through the formation of the CuCr/sub 2/O/sub 4/ phase. The presence of this phase also resulted in catalysts less prone to deactivation, as compared to copper on alumina catalysts.
- Research Organization:
- Instituto Venezolano de Investigaciones Cientificas, Caracas
- OSTI ID:
- 5648196
- Journal Information:
- J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 102:1; ISSN JCTLA
- Country of Publication:
- United States
- Language:
- English
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330702 -- Emission Control-- Carbon Monoxide
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYST SUPPORTS
CATALYSTS
CATALYTIC CONVERTERS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL ACTIVATION
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CHROMIUM COMPOUNDS
CHROMIUM OXIDES
COHERENT SCATTERING
COMPARATIVE EVALUATIONS
COPPER COMPOUNDS
COPPER OXIDES
DEACTIVATION
DIFFRACTION
EQUIPMENT
OXIDATION
OXIDES
OXYGEN COMPOUNDS
POLLUTION CONTROL EQUIPMENT
REDUCTION
SCATTERING
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION