Article ID Journal Published Year Pages File Type
5375612 Chemical Physics 2009 10 Pages PDF
Abstract
We applied the periodic density-functional theory to investigate the dehydrogenation of ethanol on the O2-4Rh/CeO2−x(1 1 1) surface with an assumption that one defect site of that CeO2 surface creates an O vacancy that an excess O2 molecule replaces. Under these conditions, the adsorption energy of ethanol is calculated to be −16.08 kcal/mol. Before formation of a five-membered ring of an oxametallacyclic compound, the hydrogen atom of O-H and that of one β-carbon hydrogen of ethanol are eliminated. The dehydrogenation continues with the loss of two hydrogens from the α-carbon, at the same time, transforming to a four-membered ring species (Rh-CH2C(O)-Rh). Scission of the C-C bond occurs at this stage with a dissociation barrier 14.38 kcal/mol, forming adsorbed products CO and CH2. The ensuing steam-reforming process (CH2 + H2O) and the mechanism of the consecutive dehydrogenation are also discussed.
Related Topics
Physical Sciences and Engineering Chemistry Physical and Theoretical Chemistry
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