Surface science studies of catalyzed methanol synthesis on model copper and Cu-Zn-O surfaces

Miscellaneous · Tue Jan 01 00:00:00 EST 1991

OSTI ID:5601973

Fu, S S

Cu-Zn-O surfaces that are catalysts for methanol synthesis from CO, CO[sub 2], and H[sub 2] are modeled using zinc oxide overlayers on copper single crystals. These studies were performed in ultra-high vacuum (UHV) utilizing Temperature Programmed Desorption, Auger Electron Spectroscopy, and Low Energy Electron Diffraction techniques. The chemisorption of O[sub 2], CO, CO[sub 2], and D[sub 2] were compared on a stepped Cu(311), and a flat Cu(110). At low pressures ([approximately]10[sup [minus]6] Torr), Cu(311) was found to be much more reactive than Cu(110) for the dissociative adsorption of CO[sub 2] and D[sub 2], and the formation of CO[sub 2] from surface oxygen and CO. Since these reactions are important in methanol synthesis, these results suggest that methanol synthesis over copper may be a structure sensitive reaction. The interaction of copper, zinc, and oxygen were examined by the deposition of submonolayers to multilayers of zinc and oxygen in UHV on Cu(110). Carbon monoxide adsorbs well on copper at 150 K and low pressures (<10[sup [minus]6] Torr), but only poorly on the oxides of copper and zinc. Carbon dioxide adsorbs on ZnO at 150 K and low pressures (<10[sup [minus]6] Torr), but not on copper or oxidized copper. The authors used a combination of CO and CO[sub 2] adsorption to follow the initial growth of two-dimensional ZnO[sub x] islands and the effect of heat and oxygen treatments on these islands. Heating above 300 K leads irreversibly to three-dimensional island formation. The interaction of methanol with model Cu-Zn-O surfaces was also studied. Oxygen was adsorbed onto the exposed copper part of the surfaces to form ZnO[sub x]/y ML O/Cu(110) surfaces. The roles of ZnO[sub x] islands and chemisorbed oxygen on copper were investigated by monitoring methanol decomposition, into surface formate and methoxy species.

• Research Organization: California Univ., Berkeley, CA (United States)
• OSTI ID: 5601973
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
10 SYNTHETIC FUELS
CARBON DIOXIDE
CHEMISORPTION
CARBON MONOXIDE
COPPER
SORPTIVE PROPERTIES
COPPER OXIDES
DEUTERIUM
METHANOL
CHEMICAL PREPARATION
OXYGEN
ZINC OXIDES
AUGER ELECTRON SPECTROSCOPY
CATALYSTS
DESORPTION
ELECTRON DIFFRACTION
MILLER INDICES
ALCOHOLS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
COHERENT SCATTERING
COPPER COMPOUNDS
DIFFRACTION
ELECTRON SPECTROSCOPY
ELEMENTS
HYDROGEN ISOTOPES
HYDROXY COMPOUNDS
ISOTOPES
LIGHT NUCLEI
METALS
NONMETALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SCATTERING
SEPARATION PROCESSES
SORPTION
SPECTROSCOPY
STABLE ISOTOPES
SURFACE PROPERTIES
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
ZINC COMPOUNDS
400201* - Chemical &amp; Physicochemical Properties
100200 - Synthetic Fuels- Production- (1990-)