The Influence Of Graphene Oxidein MgO/GR,SiO₂-ZrO₂/GR On Meerwein-ponndorf-verley Reaction Of Aromatic Ketone

Aromatic alcohols are important intermediates of pharmaceuticals,pesticides,perfumes and fine organic synthesises etc,also often used for food additives.The heterogeneous MPV reduction of aromatic ketone provides a convenient way for preparation of aromatic alcohols under mild reaction conditions.The method shows some advantages as high chemical selectivity for the reduction of C=O,but has no influence on other unsaturated bonds(C=C,C=N,N=O,etc),and simple treatment after reactionMgO/GR was prepared by the precipitation method,and SiO2-ZrO2/GR was prepared by the aerogels method.The hydrogen transfer reduction of aromatic ketones with 2-propanol was investigated over these catalysts.The catalysts were characterized with BET,XRD,TEM,TG-DTG,N2 adsorption-desorption,XPS,FT-IR,UV-Vis and CO2-TPDThe results showed that catalytic activities were significantly improved upon doping graphene on the metal oxides,and the catalytic activity of SiO2-ZrO2/GR was improvement more obviously Hybrid materials possessed high specific surface area and macro structures.The best doping of graphene was 1%.MgO/GR hybrid material that showed small crystallites dispersed on graphene and had a large amount of strong base site on catalyst surface after calcined at 400?.The surface area was effectively improved upon SiO2 addition to SiO2-ZrO2/GR hybrid material.ZrO2 and SiO2 had strong inter-molecular interaction of Si-O-Zr on the graphene surface,and increased the active center of the catalyst after calcined at 300?MgO/GR and SiO2-ZrO2/GR showed good activity in the MPV reduction of acetophenone.The results manifest that the electron-withdrawing and electron-releasing groups have a lower degree of effect to the reduction rate of acetophenone because of the ?-electron interaction between the benzene ring in the acetophenone and graphite layer of grapheme.