Gas-phase heterogeneous photocatalytic oxidation of ethanol: Pathways and kinetic modeling
- National Renewable Energy Lab., Golden, CO (United States)
The kinetics of photocatalytic oxidation of ethanol has been studied, and the formation and destruction rates of products have been measured. The important intermediates were identified as acetaldehyde, acetic acid, formaldehyde, and formic acid. Minor reaction channels resulted in the formation of methyl formate, ethyl formate, and methyl acetate. Kinetic and `dark` adsorption parameters were measured for ethanol and all of the important intermediates. We have modeled the complete oxidation process using a sequential chemical reaction mechanism. This mechanism is based primarily upon known homogeneous chemistry. However, the formation of acids from aldehydes in photocatalytic oxidation is different from known homogeneous chemistry and demonstrates the ability of the solid surface to stabilize energized transient species. We have measured the adsorption isotherms for ethanol and the oxidized intermediates and have concluded that there are two adsorption sites for some of the chemical species. We think it is possible that the adsorption properties of the compounds will change when the solid is illuminated. 42 refs., 11 figs., 3 tabs.
- OSTI ID:
- 422073
- Journal Information:
- Environmental Science and Technology, Vol. 30, Issue 10; Other Information: PBD: Oct 1996
- Country of Publication:
- United States
- Language:
- English
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