An easily recoverable and efficient natural biopolymer-supported zinc chloride catalyst system for the chemical fixation of carbon dioxide to cyclic carbonate

Chemical fixation of carbon dioxide with epoxides to form cyclic carbonates proceeds very effectively under mild conditions by using a chitosan-supported zinc chloride catalyst in conjunction with 1-butyl-3-methylimidazole halides (BMImX) without any organic solvents. Reaction temperature, carbon dioxide pressure, effects of co-catalysts and the molar ratio of catalyst to co-catalyst were investigated. The optimum reaction conditions were 110 °C and 1.5 MPa, and BMImBr was the best co-catalyst. The catalyst system was recycled and reused.