Preparation And Reaction Properties Of Bifunctional Catalysts For Oxidation Of Liquid Phase Methanol

The deep processing of methanol is an area that many countries are competing to develop.It is of great significance to convert methanol into high value-added products.As one of the high value-added products of methanol,methyl formate is an important intermediate of C1 chemistry and has broad application prospects.Methanol can be selectively oxidized to form methyl formate on a bifunctional catalyst with both oxidative and acidic properties.This method has no pollutants and is environmentally friendly.It is a development route for methyl formate.In this work,a series of Au-based and Pd-based supported catalysts with Au and Pd as main active components were prepared and characterized by XRD,FT-IR,BET,XPS,SEM and HRTEM.The catalytic performance of the catalyst in the liquid phase selective oxidation of methanol to methyl formate was evaluated in a batch reactor.The effects of metal loading,catalyst dosage and reaction conditions on the reaction performance were investigated.The following good results were obtained.(1)In the 0.5%Au/MIL-100(Fe)catalyst,Au was highly dispersed on the carrier,and the average particle diameter of the Au particles was 3.78 nm.When the Au loading was 0.5%,the catalytic activity was optimal.After reacting for 6 h at 140? temperature and 2 MPa pressure,the conversion of methanol was 34.02%,and the selectivity of methyl formate reached to 59.47%.The catalyst maintained good activity in five replicate experiments.(2)In the 2%Pd/MIL-100(Fe)catalyst,Pd was highly dispersed on the support,and the average particle diameter of the Pd particles was 5.59 nm.When the Pd loading was 2%,the catalytic activity was optimal.After reacting for 5 h at 140? temperature and 2MPa pressure,the conversion of methanol was 50.71%,and the selectivity of methyl formate reached to 57.23%.(3)The catalytic performance of 2%Pd/MIL-100(Fe)was improved after introducing Pt and Au in it.Adding Pt can increase the conversion of methanol,ang adding Au can increase the selectivity of methyl formate.Under the optimal reaction conditions,when 0.25%Pt was introduced,the conversion of methanol reached to 60.46%,the selectivity of methyl formate was 54.49%;when 0.25%Au was introduced,the conversion of methanol was 49.46%,the selectivity of methyl formate was increased to 68.20%.