Palladium Nanoparticles Supported on Titanate Nanobelts for Solvent-Free Aerobic Oxidation of Alcohols

The solvent-free selective oxidation of alcohols by O-2 without any additives has been studied using palladium nanoparticles supported on a titanate nanobelt. The catalysts were prepared by polyol reduction and impregnation with different kinds of supports. They were evaluated in oxidation reactions of benzyl alcohol. The calcined titanate nanobelt was found to be the best support for the solvent-free Pd-catalyzed oxidation of alcohols and excellent catalytic activity as well as high selectivity to the corresponding benzaldehyde could be obtained. Moreover, palladium nanoparticles immobilized on the calcined titanate nanobelt could completely suppress the formation of toluene and benzoic acid, an effect that might be caused by the enhanced basic nature and morphology of the support. The catalyst was not only active and selective towards carbonyl compounds, but also recyclable under the oxidation conditions. This catalyst was also applicable for the oxidation of other alcohols.