Synthesis Of Silicon-based Composite Metal Oxides And Study On The Catalytic Properties Of BAEYER-VILLIGER

Mesoporous silica as a new type of nano-material,exhibits three-dimensional cubic phase channel structure,high specific surface area,pore volume and tunable mesoporous structure.Based on these properties,mesoporous silica has attracted increasing consideration in adsorption/separation and catalysis field,and so on.This paper is dedicated to synthesis and modification of mesoporous silica,aims to prepare highly efficient catalysts in heterogeneous Baeyer-Villiger catalytic oxidation reaction.Core-shell magnetic mesoporous silica material through the modification of copper nanoparticles improves the catalytic performance of material.Meanwhile,because of its verticle radical channel structure,it promotes catalytic active sites contact with the organic molecules.Because of cooperative role,mesoporous silica material doped doubled metals shows better catalytic performance in heterogeneous Baeyer-Villiger catalytic oxidation reaction,high conversion rate of reactants and high selectivity of production.The main contents of this paper are listed as follows:1.Core-shell magnetic mesoporous silica material doped copper nanoparticles was synthesized by sol-gel method and hydrothermal synthesis method.With these characterized techniques such as XRD,TEM,VSM and N2 sorption-desorption isotherms,the catalyst material exhibits core-shell-shell three layer structure,high surface area and pore volume,distributed evenly copper nanoparticles and characterization of superparamagnetism.Based on these properties,the catalyst is helpful for better contact of catalytic active site and reactant and easily to be recovered.Thus,in B-V catalytic reaction,the catalyst shows better catalytic performance and repeated use.2.The mesoporous silicon doped Fe-Mo bimetallic catalyst(FeMo@MPSi)was synthesized by the method of low-temperature magnesium reduction and impregnation.With the characterizations such as XRD,TEM,SEM and N2 sorption desorption isotherms,in comparison with the SBA-15 material,the catalyst still keeps original ordered three-dimensional cubic phase structure,and have larger surface area and high pore volume.Meanwhile,it offers a lot of catalytic active sites.In addition,in B-V catalytic oxidation reaction,the mesoporous structure makes reactant and production easily to transfer in the silicon matrix.At the same time,the synergetic effect of iron and molybdenum metals doping in the catalyst could activate carbonyl carbon atoms of ketones,which could accelerate the rate of the heterogeneous BV catalytic oxidation reaction.Thus the catalyst shows better catalytic performance in BV catalytic oxidation reaction.