Preparation Of Functionalized Ionic Liquid And Study Of Electrochemical Redution Of CO₂

On one hand,carbon dioxide?CO₂?is regarded as the most significant greenhouse gas,which has caused serious environmental problems.On the other hand,CO₂ is also a naturally abundant and recyclable carbon source.Thus,the fixation and utilization of CO₂ has the profound significance.Since the thermodynamic property of CO₂ is very stable,the activation of CO₂ is usually need harsh reaction conditions—high pressure and high temperature.However,electrochemical activation of CO₂ can happen in mild condition and it is a simple and effective approach to utilize CO₂.Recently,ionic liquids have been used as a new kind of green solvent due to their good stability,high ionic conductivity,good solvating ability and low vapour pressure.Compared with organic solvent,the adsorption capacity of ionic liquids for CO₂ is much larger.In particular,the amino-functional ionic liquid,not only has physical adsorption,but chemical adsorption,so it can fix and adsorb more CO₂.In this paper,first of all,we prepared a kind of amino-functionalized ionic liquid?[NH₂-emim]Br?,and then mixed with different tranditional ionic liquids in different rations to study the electrochemical reduction of CO₂.Specific contents may be summarized as follows:1.The paper reviewed the properties?classification?preparative methods of ionic liquids,the present emission situation?fixed methods of CO₂,and the research progress of electrochemically activating CO₂ into organic carbonate in ionic liquids.2.1-?1-aminoethyl?-3-methylimidazolium bromide?[NH₂-emim]Br?was prepared and was been characterized by ¹HNMR and IR.3.The viscosity?conductivity?electrochemical window and the solubility of CO₂ of four signal ionic liquids?[Emim]BF₄?[Bmim]BF₄?[Bmim]PF₆?[NH₂-emim]Br?and three kinds of binary ionic liquids?[NH₂-emim]Br-[Bmim]PF₆?[NH₂-emim]Br-[Emim]BF₄?[NH₂-emim]Br-[Bmim]BF₄?were tested and compared.4.The electrochemical reduction behavior of CO₂ on Cu electrode in ionic liquids were studied by cyclic voltammetry.The results showed that in terms of a single ionic liquid or in binary ionic liquids the reduction of CO₂ was an irrersible process controlled by diffusion.The binary ionic liquids mixed with tranditional ionic liquids and amine-functional ionic liquid showed better electrochemical reduction performance.5.In a undivided cell,[NH₂-emim]Br?0.5%?-[Bmim]BF₄ as electrolyte,Cu electrode—working electrode,Pt electrode—counting electrode,Ag electrode—refrence electrode,the constant potential electrolysis experiments were carried out at mild condition.The yield of target product of diethyl carbonate?DEC?is 52.4%.