Decomposition of methanol, formaldehyde, and formic acid on nonpolar (1010), stepped (5051), and (0001) surfaces of ZnO by temperature-programmed decomposition

Journal Article · Wed Feb 01 00:00:00 EST 1984 · J. Catal.; (United States)

OSTI ID:6898774

Akhter, S; Cheng, W H; Lui, K; Kung, H H

The decomposition of methanol, formaldehyde, and formic acid were studied on a nonpolar (1010), a stepped (5051) and a Zn polar (0001) surface by temperature-programmed decomposition. The decomposition products on the (1010) and (5051) surfaces were similar, but the coverage and the amounts of products were consistently higher on the (5051) surface. Two pathways for decomposition of methanol are proposed, dissociatively adsorbed oxygen at 150/sup 0/C and oxidation of methoxide to a surface formate-like species. Formaldehyde and formic acid also decomposed via the surface formate. The competition between dehydrogenation and oxidation depended on the coverage such that dehydrogenation was more favored for higher coverages. Decomposition products were identified for the two pathways for the different compounds. Desorption of all the decomposition products wasreaction-limited except for water which was desorption-limited. The results indicated that the (0001) surface is more metallic in its behavior than the (1010) and (5051) surfaces. Comparison of the desorption temperatures of different compounds suggests that at room temperature, alcohols adsorb molecularly on the (0001) surface but dissociatively on the other two surfaces. On the (0001), comparison among methanol, ethanol, and isopropanol suggests that the ease of dehydrogenation parallels the strength of the ..cap alpha../sub C-H/ bond.

• Research Organization: Northwestern Univ., Evanston, IL
• OSTI ID: 6898774
• Journal Information: J. Catal.; (United States), Vol. 85:2
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
10 SYNTHETIC FUELS
ETHANOL
DECOMPOSITION
FORMALDEHYDE
FORMIC ACID
METHANOL
PROPANOLS
ZINC OXIDES
CATALYTIC EFFECTS
CATALYSIS
EXPERIMENTAL DATA
ALCOHOLS
ALDEHYDES
CARBOXYLIC ACIDS
CHALCOGENIDES
CHEMICAL REACTIONS
DATA
HYDROXY COMPOUNDS
INFORMATION
MONOCARBOXYLIC ACIDS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
ZINC COMPOUNDS
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