Comparison of the chemical properties of the zinc-polar, the oxygen-polar, and the nonpolar surfaces of ZnO
The temperature programmed decomposition results of methanol, formaldehyde, and formic acid on an O-polar (0001) surface of ZnO are presented. From these results, and similar ones for the Zn-polar (0001) and the nonpolar (1010) and (5051) surfaces, a comparison of the properties of the different ZnO surfaces are made. Oxygen-containing molecules that possess strong dipole moments, such as alcohols, formaldehyde, acetone, and formic acid, interact most strongly with the Zn-polar face, less strongly with the nonpolar face, and least strongly with the O-polar face. This leads to the observed differences in the desorption temperature of molecular desorption, temperature of evolution of the decomposition products, and the fraction of methanol decomposed. These differences are explained by the different magnitudes and orientations of surface dipole moments, a different degree of ionicity of the surface Zn ions, and a different degree of steric hindrance of surface Zn ions for the different surfaces. Desorption of other molecules, such as propene and CO, whose adsorption is dominated by different types of interaction than the alcohols and aldehydes, shows different dependence on the surface structure. 37 references, 5 figures, 3 tables.
- Research Organization:
- Northwestern Univ., Evanston, IL
- OSTI ID:
- 5034208
- Journal Information:
- J. Phys. Chem.; (United States), Vol. 89:10
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
FORMALDEHYDE
DECOMPOSITION
DESORPTION
FORMIC ACID
METHANOL
PROPANOLS
ZINC OXIDES
CHEMICAL PROPERTIES
SORPTIVE PROPERTIES
CATALYSIS
CATALYSTS
DEUTERATION
DEUTERIUM
DIPOLE MOMENTS
EXPERIMENTAL DATA
ISOTOPE EFFECTS
MONOCRYSTALS
ALCOHOLS
ALDEHYDES
CARBOXYLIC ACIDS
CHALCOGENIDES
CHEMICAL REACTIONS
CRYSTALS
DATA
HYDROGEN ISOTOPES
HYDROXY COMPOUNDS
INFORMATION
ISOTOPES
LIGHT NUCLEI
MONOCARBOXYLIC ACIDS
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
STABLE ISOTOPES
SURFACE PROPERTIES
ZINC COMPOUNDS
400201* - Chemical & Physicochemical Properties
400301 - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)