Synthesis, characterization and study of catalytic activity of Silver doped ZnO nanocomposite as an efficient catalyst for selective oxidation of benzyl alcohol

Abstract

Powder samples of Ag/ZnO nanocomposite containing different amounts of Ag were synthesized by co-precipitation method. The synthesized samples were characterized by XRD, SEM, EDX and TEM techniques. The XRD results revealed that all the samples show wurtzite hexagonal phase of ZnO. The TEM micrographs of the samples showed that size of Ag-ZnO nanoparticles was in the range of 30–50 nm. Catalytic activity was tested using liquid-phase selective oxidation of benzylic alcohols to aldehydes. The influence of some parameters such as optimum weight of Ag, catalyst dosage, oxidant and various solvents were studied. The superior catalytic performance of the Ag/ZnO nanocomposite was observed in microwave condition compared to that performed in reflux condition. The catalysts were recycled three times in the oxidation of alcohols and little change in the conversion efficiency was observed. The highly dispersed Ag metal particles on ZnO surface was considered to be responsible for the catalytic activity. Ag/ZnO nanocomposite catalysts with different Ag content were prepared by co-precipitation method. Ag/ZnO displayed good catalytic activity during liquid-phase selective oxidation of benzylic alcohols to aldehydes. The superior catalytic performance of the Ag/ZnO nanocomposite was observed in microwave condition compared to that of reflux condition.