Facile syntheses of ionic polymers for efficient catalytic conversion of CO2 to cyclic carbonates

Abstract

Two new ionic polymers IP-1 and IP-2 have been successfully synthesized, which have been developed as heterogeneous catalysts with high efficiency and recyclability for CO 2 reduction by the transformation into valuable cyclic carbonates without employing solvent and co-catalyst. • Two new and efficient ionic polymers catalysts were designed and synthesized for the CO 2 conversion. • Catalysts demonstrated high catalytic activity for the cycloaddition reaction under solvent-free, metal-free, cocatalyst-free reaction conditions. • The catalysts is easily separated from the products by centrifugation and also show excellent stability and reusability. • The yields reach 99 % under atmospheric CO 2 pressure at 100 °C. • The high-efficiency ionic polymers catalysts are facile to synthesize. The development of sustainable heterogeneous catalysts in converting carbon dioxide (CO 2 ) into value-added chemicals is a promising way to alleviate the environmental pressure caused by global warming. Here, two novel ionic polymers (IPs, namely IP-1 and IP-2 ) with high yield and excellent physiochemical stability have been synthesized facilely from the direct reaction of 1,3,5-tris(bromomethyl)benzene with 1,4-diazabicyclo[2.2.2]octane and 3,6-di(1H-imidazol-1-yl)pyridazine, respectively. Their catalytic abilities to convert CO 2 into cyclic carbonates have been explored, and both IP-1 and IP-2 show excellent catalytic activity under solvent-free, cocatalyst-free, and mild reaction conditions, and can be recycled and reused six times without decreasing their catalytic abilities. These materials are easily synthesized, and there are no metals and other additives during the catalytic process, which provides a possibility for the industrial immobilization of CO 2 to carbonate over heterogeneous catalysts.