Synthesis And Catalysis Research Of Functionalized Ionic Liquid

As major greenhouse gas and a secure,low-cost,non-toxic,abundant and easy obtained C1 resource,the utilization of CO2 was great importance for solving the energy crisis and protecting the global environment.For chemical fixation of CO2,the most representative methods is conversion of CO2 and epoxide to form cyclic carbonate,and the research of this reactiion has received extensive attention.Recently,a large amount of catalyst were exploited and used to catalyze the cycloaddition of epoxide and CO2,such as organic bases,metal oxides,zeolites,quaternary ammonium salts,ionic liquids,salen complexes,metalloporphyrin,phthalocyanine.Among them,ionic liquids are applied to the cycloaddition reaction of CO2 and epoxy compounds because of its excellent physicochemical properties,and have shown good catalytic activity.In this paper,we designed and synthesized several kinds of functionalized ionic liquids,and their catalytic performance and catalytic mechanism in the cycloaddition of CO2 and epoxides were studied.The main contents are as follows:1.The design,synthesis and catalytic performance of hydroxyl or carboxyl functional imidazolium ionic liquids.A series of hydroxyl or carboxyl functional imidazolium ionic liquids were designed and synthesized,the catalytic performance of the cycloaddition reaction of epoxide with CO2 was researched.The results show that the synthetic imidazolium ionic liquids containing hydroxyl and carboxyl functional groups can effectively catalyze the cycloaddition reaction of epoxides with CO2,and catalytic performance of 1-carboxypropyl-3-methylimidazolium bromine ionic liquid is the best.Simultaneously,these catalysts exhibit good substrate suitability for different epoxides.The optimal reaction conditions for the catalytic reaction was discussed.And the result is as follows:catalyst loading is 0.20 mol%(relative to epoxide),initial pressure is 4.0 MPa,reaction temperature is 130?,reaction time is 4h.Under the reaction condition,the yield of the product is 94.64%.The catalyst was used for five times without appreciable loss catalytic activity which indicated that the catalyst had a good recycled performance.2.The design,synthesis and catalytic performance of benzyl functionalized imidazolium ionic liquidsA series of benzyl functionalized imidazolium ionic liquids were designed and synthesized,the catalytic performance of the cycloaddition reaction of epoxides with CO2 was studied.The experimental results showed that the benzyl functionalized imidazolium ionic liquids can effectively catalyze the cycloaddition of epoxides with CO2,The catalytic performance of 1-(2-methylbenzyl)-3-methylimidazolium chlorine ionic liquid is the best.These catalytic system also exhibit good applicability for different epoxides.The optimal reaction conditions for the catalytic reaction was discussed.The results showed that the optimum reaction conditions are as follows:the catalyst dosage is 0.25 mol%,the initial pressure is 2.0 MPa,the reaction temperature is 130?,and the reaction time is 4h.Under these conditions,the yield of the product is 94.89%.The catalyst was used for five times without appreciable loss of catalytic activity which indicated that the catalyst had a good recycled performance.The mechanism of this reaction is analyzed by theoretical calculation,and the results show that the possible catalytic mechanism of these catalysts is three-step reaction mechanism.