The Preparation Of Catalysts Supported On TiO₂/KIT-6 And The Study Of Their Photocatalytic Performance For Oxidation And Amination Of Benzyl Alcohol

Gold nanoparticles can be excited by visible light for the surface plasmon resonance effect.Gold nanoparticles on supports are often used as photocatalysts and have a high catalytic activity for the selective oxidation of benzyl alcohol to benzaldehyde and the synthesis of imine from benzyl alcohol and aniline,especially in photocatalytic oxidation reactions.In this article,a series of Au/TiO₂/KIT-6 photocatalysts with different amount of Au loadings are prepared.The photocatalytic activities of the selective oxidation of benzyl alcohol to benzaldehyde and the synthesis of imine from benzyl alcohol and aniline are detected using Au/TiO₂/KIT-6 under visible light irradiation at ambient temperature and normal pressure.The morphology,structure,and valence state of the photocatalysts are characterized by TEM,XRD,SAXS,UV-vis DRS,XPS and BET,etc.The results are shown as follows:?1?Au/TiO₂/KIT-6 photocatalysts are prepared by NaBH4 reduction method.UV-vis DRS results indicate that the catalysts have a wide and strong absorption peak in the visible light range.TEM results show that the average size of Au nanoparticles is 4.03nm.Au nanoparticles are uniformly distributed on the surface and channels of KIT-6 in the form of spherical particles.XPS results show that Au nanoparticles exist in metallic state.?2?The catalytic activities of the oxidation of benzyl alcohol and the synthesis of imine on Au/TiO₂/KIT-6?5%?are superior.The effects of different kinds of solvents,bases and their amounts,catalysts and their amounts,different amounts of reactants and different reaction atmospheres on the reactions are investigated.?3?Under the optimum reaction conditions,the activities of different alcohol derivatives and amine derivatives are detected.The effects of different light intensities and wavelengths on the synthesis of imine from benzyl alcohol and aniline are performed.The recyclability of the catalysts is investigated,too.A possible photocatalytic mechanism for the synthesis of imine from benzyl alcohol and aniline over Au/TiO₂/KIT-6 photocatalysts is proposed.?4?Bimetallic Au-Ru/TiO₂/KIT-6 photocatalysts are prepared and characterized.The photocatalytic activities on Au-Ru/TiO₂/KIT-6 are detected for the synthesis of imine from benzyl alcohol and aniline.