Performance Of Starch-Based Carbon Contained Cu Catalyst Preparation And Catalytic Synthesis Of Dimethyl Carbonate

Dimethyl carbonate (DMC) is an important green chemical, known as "new base blocks" of organic synthesis, which can be used as a new environmentally friendly additive, for example, gasoline and diesel. In addition, it can be used in the field of high-performance resin and drug intermediates. It caused great attention for security, stability, better development and application prospect.Although chlorine catalysts have better selectivity and activity, they can cause deactivation of the catalyst as well as corrosion of the equipment for the loss of Cl-1. So they have been eliminated. The study found that activated carbon load chlorine-free copper-based catalyst has a very high reactivity and overcomes the defects of the chlorine catalysts. Presently, the activated carbon needs acid-modified or base-modified processing, then steep in active ingredient. This method is relatively cumbersome.SOL-GEL method has been applied to the preparation of the catalyst, because it can mix with trace elementsuniformLy on the molecular level. So starch as carbon and gel material is widely used in the preparation of new carbon materials. This article used copper nitrate and soluble starchas raw materials toprepare acomposite colloid at500degrees centigrade, under N2atmosphere, then activated with KOH at different temperature, under H2atmosphere. Then we got charcoalloadscopper catalyst(Cu/C).We did characterization and analysis on microstructure, structure and phase composition of catalysts with SEM, TEM, XRD, TG, N2adsorption and CO-TPD, then investigated the influences of activation temperature, activator dosage and add another additive K2CO3for the catalytic activity. The maincontents and conclusionsare as follows:(1) Exploredthe effects of different activation temperatureon Cu/C catalyst’s structure and catalytic performance on500degrees centigrade. The results showed that the activation temperature had an important effect on the pore structure of the catalyst. The ratio of surface area of the activated carbon, the micropore volume and the total pore volume increased firstly, then decreased, on500-900degrees centigrade, but bore diameter of the micropore changed slightly.(2) The research found that specific surface area of the starch-based carbon supported Cu catalyst could reach1690m2·g-1, micropore volume rate was72.4%. The requirements:carbonization temperature was500temperatures, KOH and carbon mass ratio was1:1and activation temperature was850degrees centigrade.(3) When the condition was KOH and carbon mass ratio was1:1,850degrees centigrade, the Cu/C catalyst which prepared with sol-gel method was optimum. Cu0dispersed in the catalystuniformLy. The method was so easy that it can be widely applied in future.(4) In a reaction catalytic activity declined after10hours because Cu0was oxidized by O2. The sample was reduced in H2atmosphere for2hours, then its activity could restore to more than90%.(5) Investigated the influence on catalyst by adding another activator, and found that adding5wt%K2CO3in KOH improved Cu0enrichment and dispersion of the surface of the carrier. So it could significantly improve the activity of the catalyst.