Participation of Al/sub 2/O/sub 3/ hydroxyl-shell oxygen in the catalytic oxidation of carbon monoxide over Pd/Al/sub 2/O/sub 3/ and Pd. Cu/Al/sub 2/O/sub 3/ catalysts
This paper studies the mechanism of low temperature CO oxidation over catalysts of 0.003%-0.1 wt.% palladium supported on gamma-Al/sub 2/O/sub 3/, and over a solid solution of copper in gamma-Al/sub 2/O/sub 3/ (0.5-3.0 wt.% CuO). In order to obtain information about the reactive forms of oxygen in CO oxidation over these catalysts, the authors used tagged oxygen (ca 80 atom %) and secondary ion mass spectrometry. To confirm the effect of oxygen isotope exchange on the tracer content of the CO/sub 2/, CO oxidation was carried out with CO/sub 2/ freeze-out in the cycle. CO oxidation over supported palladium, under conditions of reduction or of catalysis, can go via reaction with OH oxygen atoms, but the temperature ranges of these conditions differ by more than 250 degrees. It is noted that over Pd.Cu/Al/sub 2/O/sub 3/ catalysts the mechanism represented is only partly realized. Along with OH oxygen, an adsorbed form of oxygen evidently also contributes to CO formation over these catalysts.
- Research Organization:
- L.Y. Karpov Sci-Res. Institute for Physical Chemistry
- OSTI ID:
- 7222695
- Journal Information:
- Dokl. Phys. Chem. (Engl. Transl.); (United States), Vol. 284:4
- Country of Publication:
- United States
- Language:
- English
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Mechanism of carbon monoxide oxidation on supported catalysts. II. Nature of stationary state of surface as influenced by reaction conditions on Pd/Al/sub 2/O/sub 3/
Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALUMINIUM OXIDES
CATALYTIC EFFECTS
ISOTOPIC EXCHANGE
CARBON MONOXIDE
OXIDATION
COPPER
HYDROXYL RADICALS
PALLADIUM
CARBON DIOXIDE
CATALYST SUPPORTS
CHEMICAL REACTION KINETICS
ION MICROPROBE ANALYSIS
MASS SPECTROSCOPY
OXYGEN 16
OXYGEN 18
TRACER TECHNIQUES
ALUMINIUM COMPOUNDS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
ELEMENTS
EVEN-EVEN NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGHT NUCLEI
METALS
MICROANALYSIS
NONDESTRUCTIVE ANALYSIS
NUCLEI
OXIDES
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
PLATINUM METALS
RADICALS
REACTION KINETICS
SPECTROSCOPY
STABLE ISOTOPES
TRANSITION ELEMENTS
400201* - Chemical & Physicochemical Properties
400202 - Isotope Effects
Isotope Exchange
& Isotope Separation