Synthesis And Catalytic Performance Of Copper Based Catalysts For Dimethyl Oxalate To Ethylene Glycol

Ethylene glycol as a high value chemical product, are widely used as the raw material of polyester resin, polyester fiber and so on. In recent years, the domestic demand of ethylene glycol is rising every year. And the yields of ethylene glycol produced domestic, however, can not meet the market needs. Therefore, in our country, the glycol industry has good market prospects.At present the mainly method used for the industrial production of ethlene glycol is based on the direct hydrolysis of ethylene oxide obtianed from oil as raw material. However this method is plagued by some problems such as the increased price of crude oil as a result of the long-term of shortage and high energy consumption for the distillation of the large amount of excess water etc. to deal with these problems, it is wise choice to prepare ethylene glycol by anternative processes based on non oli routes taking into account the advantages of sources of raw material and the characteristics of oil-poor and coal-rich country. Synthesis of ethylene glycol from CO via oxalate ester is two-step process. The first step is oxalate ester synthesis by CO coupling,the second step is synthesis of ethylene glycol by hydrogenation of oxalate ester.A series of Cu-based catalysts were prepared by ammonia-evaporation method, their supports were silica sol, SBA-15, fumed silica, ZSM-5(50), and their content of Cu is20%. Those catalysts were evaluated and characterized by XRD, H2-TPR, NH3-TPD. The results show that the catalyst whose support is fumed silica has the highest dimethyl oxalate conversation and ethlene glycol selectivity. And by-product of hydrogenation may be influenced by the acidity of catalysts. Another series of Cu-based catalysts were prepared by ammonia-evaporation method, their supports were fumed silica but the content of Cu were varies from5%to40%. Those catalysts were also evaluated and characterized by XRD, H2-TPR, FT-IR. The results show that the catalyst with20%Cu has the highest dimethyl oxalate conversation and ethlene glycol selectivity, reached～100%and84%. At last, the catalyst whose support was fumed silica and content of Cu was20%was evaluated at different temperature, pressure and the molar ratio of H2and dimethyl oxalate. It was found that the different reaction conditions had different inpact on the hydrogenation performance.