Application Of Metal Nanoparticle Catalyst In Oxidation Reaction

Gold nano-particles catalyst is a hot topic in the current research.Carbon materials also have been widely used in recent years.However,only after when carbon materials combined with gold nanoparticles,they obtain good photoelectric properties and catalytic properties,and use in industrial,medical and other field.In this paper,t-butyl hydroperoxide was used as oxidant,and the catalytic activity of gold nanoparticles supported on different carbon materials(heterogeneous catalyst)was tested.The main reaction was the solvent-free oxidation of1-phenylethanol.In this paper,the catalytic activity of the catalysts under different reaction conditions were tested.Including different reaction times(30-120 min),different reaction temperatures(50-150 °C),the amount of catalysts(1-5 ?mol),the amount of oxidant(5-10 mmol)and the amount of additive(2.5 mol%).Gold nanoparticles(1 wt.%)supported on a variety of carbon materials(activated carbon,graphite,silicon carbide,carbon xerogel,nanodiamonds,and microdiamonds),by two different methods(colloidal method and double impregnation),were used as catalysts for the oxidation of 1-phenylethanol.A maximum yield of acetophenone(99.9%)was obtained with Au nanoparticles supported on microdiamonds by colloidal method,And the reaction time was 120 min,the reaction temperature was 150 °C,the amount of catalyst was 5 ?mol and the amount of the oxidizing agent was 10 mmol,while Au nanoparticles supported on silicon carbide by double impregnation method led to the minimum yield of27.1%.Moreover,catalyst recyclability was tested up to six consecutive cycles at the optimized conditions for each catalyst,and it was observed that the catalytic activity of gold nanoparticles supported on microdiamonds,prepared by the colloidal method,maintains higher activity when compared with other catalysts after several reaction cycles.In addition,copper nanoparticles supported on carbon nanotubes were tested for degradation of dyes.