Preparation Of Multifunctional Ionic Liquid And Study On Catalytic Synthesis Of Cyclic Carbonate

Transformation of carbon dioxide as a C1 building block into fine chemicals has attracted increasing attention over the past decades. Among the various pathways explored for transformation of carbon dioxide, the cycloaddition of carbon dioxide with epoxides to cyclic carbonates has caught the most attention. Up to now, a wide range of catalytic systems have been developed for the cycloaddition reactions of carbon dioxide with epoxides to cyclic carbonates. Among these candidates, ionic liquids(ILs) have been reported as one of the most efficient catalysts due to their characteristic physical and chemical properties.Difunctional ionic liquids with dual functional groups were synthesized and characterized, and its catalytic performance for coupling reaction carbon dioxide and epoxides was investigated. Under the optimized reaction conditions(110 ℃、1.0 MPa、2.0 h), the propylene carbonate was yield to 96.5% when HOOCPIm IEOH was used as the catalyst. Besides, HOOCPIm IEOH was also highly active for various epoxides to react with carbon dioxide and the catalyst could be reused for 10 times without any losses in yield of propylene carbonate.Metal functionalized ionic liquids with different Lewis acid/base were synthesized and characterized, and its catalytic activity for coupling reaction carbon dioxide and epoxides were carried out. Under the optimized conditions(110 ℃、1.5 MPa、2.0 h), the propylene carbonate was yield to 96.1% when(Mim Breim Br-COO)2Zn was employed as the catalyst. Furthermore,(Mim Breim Br-COO)2Zn was also highly active for various epoxides to react with carbon dioxide and the catalyst could be reused for 15 times without almost any losses in yield of propylene carbonate.Synthesis and characterization of multi-layer supported ionic liquids with double imidazole groups were carried out, and their catalytic performance for cycloaddition reaction were investigated. Compared to conventional supported ionic liquids, multi-layer supported ionic liquids showed the excellent catalytic activity in the cycloadditon of carbon dioxide and epoxides. Under the optimal reaction conditions, propylene carbonate was yield to 94.4% when the loading of multi-layer supported ionic liquids was 0.9mol%. Besides, it was applicable for CO2 to react with various epoxides and the higher stability was shown in the coupling reaction of carbon dioxide and epoxides.