Studies On The Nanostructured Maghemite-Supported Metallic Catalysts For The Oxidation

Both the oxidation of alkene into the corresponding epoxides, aldehydes, ketones or acids and the oxidation of toluene into benzaldehyde and/or benzoic acid are the very important in chemical industry. These oxidized products are widely used to synthesize alcohol, epoxy resins, surfactants, et al. Recently, various approaches have been attempted to selectively oxidize alkene and toluene. The different metals and metallic oxides are aboardly utilized for these reactons, such as silver, gold, cobalt, manganese, copper, vanadium, et al.Herein, we designed new magnetically recoverable metallic catalysts for the oxidation of alkene and toluene. We chose the magnetic y-Fe2O3 nanoparticles as the support, nanometal composites as a catalytically active component, and solid base NaOH, KOH, CeO2 and La2O3 or Lewis acid AlCl3 as the additives. These catalysts are green, highly active., easily separable and recyclable. The effects of preparation conditions and reaction conditions on catalystic activity were investigated in detail. It was shown that the supported silver catalysts Ag/KOH-y-Fe2O3 were highly efficient for epoxidation. The addition of KOH was found to enhance the catalytic activity and selectivity significantly, and also make catalyst easily separable and recyclable at the end of the reaction. This catalytic system can avoid the environmental pollution by the addition of solubility base. For the oxidation of toluene, it was found that the addition of Lewis acid AlCl3 can affect the catalytic activity.