Silica-supported Au-Cu alloy nanoparticles as an efficient catalyst for selective oxidation of alcohols

Silica-supported Au-Cu and Au-Ag alloy nanoparticles were synthesized, characterized, and tested for the aerobic oxidation of alcohols. The results showed that Au-Cu alloy catalyst exhibited good activity and selectivity to aldehydes for a variety of structurally diverse alcohols and a strong synergistic effect was found between Au and Cu. In contrast, Au-Ag alloy catalysts were less active and selective for the oxidation of alcohols although they have very similar particle sizes to the Au-Cu alloy catalysts. Besides the chemical compositions, the pretreatment conditions were found to affect significantly the catalytic performances, and the reduction treatment is necessary for obtaining a high activity and selectivity, suggesting Au-Cu alloy is the active phase. Moreover, the catalyst could be reused if only the catalyst after the reaction was subjected to reduction treatment. (C) 2012 Elsevier B.V. All rights reserved.