Temperature-programmed desorption and infrared study of CO and H/sub 2/ adsorption on Cu/ZnO catalysts

Journal Article · Tue Mar 01 04:00:00 EST 1988 · J. Catal.; (United States)

OSTI ID:5262259

Roberts, D L; Griffin, G L

The authors have characterized a series of Cu/ZnO catalysts prepared by several methods, using a combination of adsorbate uptake measurements, temperature-programmed desorption, and FTIR spectroscopy applied to CO, H/sub 2/, and O/sub 2/ adsorbates. Adsorbed CO is present on the reduced catalysts in several adsorption states which are distinguished by different vibrational frequencies in the range 2104-2067 cm/sup -1/, and which desorb with apparent activation energies in the range 10-16 kcal/mol. When CO is adsorbed on oxidized catalysts, the frequencies shift to 2136-2110 cm/sup -1/ and the highest desorption energy increases to 19 kcal/mol. For H/sub 2/ adsorbed on reduced catalysts, a single desorption state which has an apparent activation energy of 20-21 kcal/mol is observed. When H/sub 2/ is adsorbed on oxidized catalysts, the desorption energy of this state increases to 26-27 kcal/mol. For the reduced catalysts, the amounts of reversible CO and H/sub 2/ adsorbed are found to correlate linearly with the amount of O/sub 2/ chemisorption measured at 98 K, with relative uptakes for CO, H/sub 2/, and O/sub 2/ in the ratio 9:2:10. These results are interpreted to suggest that Cu is present as metallic clusters which expose a large fraction of high-index surface planes and that the chemical behavior of these planes is significantly differed from that of low-index single crystal planes. 38 references.

• Research Organization: Univ. of Minnesota, Minneapolis
• DOE Contract Number: FG02-85ER13392
• OSTI ID: 5262259
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 110:1; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010408* -- Coal
Lignite
& Peat-- C1 Processes-- (1987-)
ACTIVATION ENERGY
ADSORPTION
ALCOHOLS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
COPPER
DESORPTION
ELEMENTS
ENERGY
FOURIER TRANSFORMATION
HYDROGEN
HYDROXY COMPOUNDS
INFRARED SPECTRA
INTEGRAL TRANSFORMATIONS
METALS
METHANOL
NONMETALS
ORGANIC COMPOUNDS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
REDUCTION
SORPTION
SORPTIVE PROPERTIES
SPECTRA
SURFACE PROPERTIES
SYNTHESIS
TEMPERATURE DEPENDENCE
TRANSFORMATIONS
TRANSITION ELEMENTS
ZINC COMPOUNDS
ZINC OXIDES