Vinyl acetate synthesis on Au/Pd(111) alloys

CALAZA, FLORENCIA C.; STACCHIOLA, DARIO J.; LI, ZHENJUN; TYSOE, WILFRED T.

Chicago, IL

Conferencia; 233rd ACS National Meeting; 2007

AMERICAN CHEMICAL SOCIETY

Acetic acid , ethylene and oxygen react in the presence of palladium catalysts to give Vinyl Acetate, but combustion of reactants and products to carbon dioxide and water is a secondary reaction which lowers the selectivity. In the last years, the addition of gold has shown an increment in selectivity. Despite of its importance very little is known about the reaction mechanism and the role of gold for the high selectivity obtained. We have elucidate the mechanism and decomposition pathways of vinyl acetate on Pd(111). Now we focus our research to the interaction of each reactant with Au/Pd(111) alloys to understand the role of gold in the reaction. Some preliminary results were obtained for the synthesis of VAM at very low gold covarages, between 2% and 5% of Au, showing important electronic effects due to Au on the surface, wich in turn affect the selectivity of the reaction.