Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9595009 | Surface Science | 2005 | 13 Pages |
Abstract
The surface chemistry of vinyl acetate on clean Pd(1 1 1) is explored experimentally in ultrahigh vacuum using reflection absorption infrared spectroscopy (RAIRS) and temperature-programmed desorption (TPD) combined with density functional theory (DFT) calculations. The relative intensities of the vibrational features of a vinyl acetate overlayer are in good agreement with the structure calculated by DFT. Furthermore, the calculated heat of adsorption of vinyl acetate (63.4 kJ/mol) is in excellent agreement with the measured desorption activation energy (65 ± 7 kJ/mol). The thermal decomposition pathways of adsorbed vinyl acetate are relatively complex involving initial cleavage of the O-acetyl or O-vinyl bonds to form either vinyloxy and acetyl, or acetate and vinyl species, respectively on the surface. The acetate thermally decomposes to desorb methane at â¼260 K, while the acetyl and vinyloxy species isomerize and react to form acetaldehyde or methane. Ethylidyne is formed, and adsorbed CO either desorbs or oxidizes to CO2 at â¼450 K.
Related Topics
Physical Sciences and Engineering
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Physical and Theoretical Chemistry
Authors
Florencia Calaza, Dario Stacchiola, M. Neurock, Wilfred T. Tysoe,