Highly efficient capture and conversion of CO2 into cyclic carbonates from actual flue gas under atmospheric pressure

Chemical conversion of CO 2 to cyclic carbonates is one of the most attractive strategies for CO 2 capture and storage utilization. Herein, a binary organocatalyst of 3-aminobenzylalcohol/ n -Bu 4 NI was used to gently catalyze the insertion of CO 2 into the terminal/internal epoxides to generate cyclic carbonates under metal-free and solvent-free conditions. Twelve representative terminal epoxides reacted with CO 2 to achieve excellent cyclic carbonate yields of up to 98.3 % at 30 °C and 1 atm CO 2 and six low activity internal di-substituted epoxides were converted to corresponding cyclic carbonates with yields of up to 96.2 %. Experiments on actual flue gas and water resistance revealed the potential industrial value of this binary organocatalyst. The yield of cyclic carbonate reached 99 % by using actual flue gas under very mild conditions of 60 °C and 1 atm. The results of 4-fold epoxide amplification experiment showed that the residual CO 2 in the flue gas was only 793 ppm after reaction at 1 atm and 60 °C, indicating the good CO 2 capture and conversion ability. Reaction kinetics and catalytic mechanism of the cycloaddition were investigated in detail. The synergistic effect among functional groups of catalysts on substrates is the essential factor for the high activity of the catalyst.