Probing Reaction Pathways on Model Catalyst Surfaces: Vinyl Acetate Synthesis

GAO, FENG; WANG, YILIN; CALAZA, FLORENCIA C.; STACCHIOLA, DARIO J.; TYSOE, WILFRED T.

Milwaukee, WI

Encuentro; 2008 AVS Prairie Chapter Meeting; 2008

American Vacuum Society

Vinyl acetate is formed on supported palladium and palladium-gold alloy catalysts from ethylene, acetic acid and oxygen, were the reaction selectivity on the alloy is improved compared to pure palladium. Surface science strategies are used to understand catalytic reaction pathways on model catalysts. The pathway for the synthesis of vinyl acetate from ethylene acetic and oxygen is explored on a Pd(111) single crystal, where it is shown that vinyl acetate is synthesized by reaction between ethylene and an acetate species to form a acetoxyethyl intermediate, which decomposes via a â-hydride elimination reaction to form vinyl acetate. The reaction pathway on a model Au/Pd(111) alloy appears to be different from that on palladium and proceeds via the initial formation of a vinyl species that inserts into the surface acetate to form vinyl acetate. reaction to form vinyl acetate. The reaction pathway on a model Au/Pd(111) alloy appears to be different from that on palladium and proceeds via the initial formation of a vinyl species that inserts into the surface acetate to form vinyl acetate. reaction to form vinyl acetate. The reaction pathway on a model Au/Pd(111) alloy appears to be different from that on palladium and proceeds via the initial formation of a vinyl species that inserts into the surface acetate to form vinyl acetate. reaction to form vinyl acetate. The reaction pathway on a model Au/Pd(111) alloy appears to be different from that on palladium and proceeds via the initial formation of a vinyl species that inserts into the surface acetate to form vinyl acetate. reaction to form vinyl acetate. The reaction pathway on a model Au/Pd(111) alloy appears to be different from that on palladium and proceeds via the initial formation of a vinyl species that inserts into the surface acetate to form vinyl acetate. reaction to form vinyl acetate. The reaction pathway on a model Au/Pd(111) alloy appears to be different from that on palladium and proceeds via the initial formation of a vinyl species that inserts into the surface acetate to form vinyl acetate. â-hydride elimination reaction to form vinyl acetate. The reaction pathway on a model Au/Pd(111) alloy appears to be different from that on palladium and proceeds via the initial formation of a vinyl species that inserts into the surface acetate to form vinyl acetate.