Synthesis Of Dimethyl Carbonate By Electro-reduction Of Carbon Dioxide In Binary Ionic Liquid

With the rapid development of the global economy and industrialization,large-scale use of fossil fuel to make C02 in atmosphere was increasing and had become a major component of greenhouse gases.To effectively alleviate the "greenhouse effect",reducing the C02 content in atmosphere,in addition to the implementation of energy conservation,but how to recycle use cheap and abundant reserves of C1 resources,achieve resource utilization had become the focus of attention of scientists.Since thermodynamic properties of carbon dioxide is very stable,the activation of carbon dioxide is usually need harsh reaction conditions,researchers had been conducted extensive research using catalytic technology for CO2 organic resources,but the process of industrialization was slow.In recent years,with the rapid development of electrochemical clean synthetic technology and ionic liquid preparation technology,how to use electrochemical technology to achieve CO2 organic resources had become one of the hot research.The electrochemical reduction of ionic liquid in the activation of C02 and methanol synthesis of DMC were studied.Aimed at undle mild reaction conditions,using CO2 and methanol to synthesis green chemical DMC,through screening of ionic liquids and the electrochemical reaction proper conditions.In order to make a little contribution to the realization of the development of CO2 resource utilization.The characterization and performance of several selected ionic liquids were studied,and through compound prepared better performance binary ionic liquid([bmim]BF4/[bmim]PF6).The electrochemical reduction of C02 in different ionic liquids were studied to investigate the scan rate,reaction temperature on the electrochemical reduction process,the results indicated that either in a single or in binary ionic liquid the reduction of C02 were controlled by diffusion irreversible process.This paper based on the optimized reaction conditions,by potentiostatic technique,using CO2 and methanol to synthesis DMC in binary ionic liquids,used GC-MS to characterize the products,recycling of ionic liquid were studied,obtained the expected results.The main research content is as follows:1.Under mild conditions,the electrochemical reduction behavior of CO2 on Cu electrode in single ionic liquids([emim]BF4,[bmim]BF4,[hmim]BF4,[omim]BF4 and[bmim]PF6)and binary ionic liquid([bmim]BF4/[bmim]PF6)were studied by cyclic voltammetry.The effect of temperature and scan rate were also investigated.The results showed that in terms of a single ionic liquid or in composite ionic liquid the reduction process of C02 was controlled by diffusion.2.Under mild conditions,the electrolysis experiments were carried out by constant-potential electrolysis in an undivided cell.Research discussed the effect of work potential,temperature and volume of different ionic liquid ratio to the yield of DMC.From the experimental results obtained binary ionic liquid[bmim]BF4/[bmim]PF6 volume ratio of 5/1,electrolysis potential of-1.6V,the temperature is 55?,the reaction proceeds in the target product yield of 82.1%DMC.Combined with the existing literature on the reaction mechanism made a preliminary estimate.