Methanol adsorption and decomposition on oxygen-precovered rhodium(111)
The adsorption, desorption, and reaction of methanol on oxygen-covered Rh(111) surfaces have been studied under ultrahigh vacuum (UHV) by using Auger electron, electron energy loss (in the electronic range), and thermal desorption spectroscopy. In the presence of oxygen adatoms the surface concentration of chemisorbed methanol increased, as indicated by the enhancement of the losses at 13.7-13.9 and 12.1-11 eV, and by the increased amount of decomposition products of chemisorbed species at higher temperature. It is proposed that the role of adsorbed oxygen is to promote the dissociative adsorption of CH/sub 3/OH by forming a strong O-H bond which hinders the associative desorption of CH/sub 3/OH. As a result, the surface concentration of irreversibly bonded methoxy species is increased. At the optimum oxygen coverage, Theta/sub O/ approx. = 0.15-0.2, the number of methoxy species was twice that on clean Rh(111). Chemisorbed oxygen exerted a slight stabilizing effect on the methoxy species, which was stable up to about 200 K, but then decomposed and reacted with chemisorbed oxygen to yield H/sub 2/, CO, H/sub 2/O, and CO/sub 2/.
- Research Organization:
- Univ. of Szeged, Hungary
- OSTI ID:
- 5911982
- Journal Information:
- J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 88:25; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
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10 SYNTHETIC FUELS
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ADSORPTION
ALCOHOLS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON MONOXIDE
CARBON OXIDES
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
DATA
DECOMPOSITION
ELEMENTS
EXPERIMENTAL DATA
HYDROGEN
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INFORMATION
METALS
METHANOL
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PLATINUM METALS
RHODIUM
SORPTION
TRANSITION ELEMENTS
WATER