Recent progress of catalysts for synthesis of cyclic carbonates from CO2 and epoxides

With the continuous emission of greenhouse gases, the rational transformation and utilization of CO2 is particularly important. Cyclic carbonates are a kind of versatile compounds and have wide applications in Li-ion batteries, pharmaceutical manufacturing and many fine chemicals. Cycloaddition of CO2 and epoxide to synthesize cyclic carbonates is considered one of the most promising CO2 conversion routes because of its 100% atomic economy, non-toxicity, as well as a more economic technical route for the utilization of CO2. In this paper, this review surveys the synthesis of cyclic carbonates employing CO2 as a building block. The mechanisms of CO2 activation have been described in detail due to the thermodynamic stability of CO2 molecule. The reaction mechanism of CO2 and epoxide is expounded, and seven CO2 activation methods are summarized and compared, deeply analyzing the research progress of recent years. To reduce the activation energy of the CO2 conversion, the utilization of catalysts is very crucial. Various types of catalysts suitable for the synthesis of cyclic carbonates derived from CO2 have been expounded in depth. Finally, the development trend of catalysts is prospected. The development of improved catalysts is strongly demanded for successful commercialization of CO2 transformation technologies. This review enables researchers to timely seize the current advancements and thus may provide some rewarding insights for future investigations on the synthesis of cyclic carbonates employing CO2 as the feedstock. It will provide a good reference and guide for scholars to achieve the better improvements.