Size Effect of Silica-supported Gold Clusters in the Microwave-assisted Oxidation of Benzyl Alcohol with H2O2

Gold clusters with average diameters of 0.8, 1.5, and 1.9 nm were prepared on mesoporous silica (SBA-15) by controlling the calcination time of an Au-11(PPh3)(7)Cl-3/SBA-15 composite. It was found that the catalytic activity for benzyl alcohol oxidation decreased monotonically with the increase in size.