Carbon monoxide oxidation over three different oxidation states of copper: Metallic copper, copper (I) oxide, and copper (II) oxide - a surface science and kinetic study

Journal Article · Wed Jun 01 00:00:00 EDT 1994 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1994.1173· OSTI ID:7084551

Jernigan, G G; Somorjai, G A ^[1]

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1. Lawrence Berkeley Lab., CA (United States)

Reaction rates and activation energies were measured for carbon monoxide oxidation over thin films of metallic copper, copper (I) oxide, and copper (II) oxide grown on graphite. The reactions were carried out in the temperature range 200-350[degrees]C at total pressures of 100 Torr. Auger Electron Spectroscopy (AES) and X-ray Photoelectron Spectroscopy (XPS) were used to characterize the growth and oxidation states of the copper films before and after catalytic reactions. The stability of a given oxidation state of copper under reaction conditions were found to be a function of the oxidizing power of the CO/O[sub 2] partial pressure ratio: Metallic copper, Cu[sub 2]O, and CuO were stable at 97/3, 90/10, and 66/33 ratios, respectively. The rate of reaction at 300[degrees]C decreased with increasing copper oxidation state (Cu > Cu[sub 2]O > CuO) and the activation energy increased with increasing copper oxidation state (Cu 9 < Cu[sub 2]O 14 < CuO 17 kcal/mol). The kinetic parameters for CO oxidation over platinum foil was tested at a 66/33 CO/O[sub 2] ratio for comparison. The reaction rate over platinum was approximately equal to that over metallic copper at 300[degrees]C and had a larger activation energy (20 kcal/mol) than CuO. The possible mechanisms for CO oxidation over the different oxidation states of copper are discussed. 30 refs., 8 figs., 1 tab.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 7084551
• Journal Information: Journal of Catalysis; (United States), Vol. 147:2, Issue 2; ISSN 0021-9517
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
01 COAL, LIGNITE, AND PEAT
33 ADVANCED PROPULSION SYSTEMS
CARBON MONOXIDE
OXIDATION
COPPER
CATALYTIC EFFECTS
COPPER OXIDES
ABSORPTION SPECTROSCOPY
ACTIVATION ENERGY
AUGER ELECTRON SPECTROSCOPY
CHEMICAL REACTION KINETICS
HETEROGENEOUS CATALYSIS
PHOTOELECTRON SPECTROSCOPY
STRUCTURAL CHEMICAL ANALYSIS
X-RAY SPECTROSCOPY
CARBON COMPOUNDS
CARBON OXIDES
CATALYSIS
CHALCOGENIDES
CHEMICAL REACTIONS
COPPER COMPOUNDS
ELECTRON SPECTROSCOPY
ELEMENTS
ENERGY
KINETICS
METALS
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
SPECTROSCOPY
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
400201* - Chemical &amp; Physicochemical Properties
010800 - Coal
Lignite
&amp; Peat- Waste Management
330702 - Emission Control- Carbon Monoxide