Construction of hyper-crosslinked ionic polymers with high surface areas for effective CO2 capture and conversion

The design and preparation of ionic liquids functionalized polymer materials is a trending topic in the fields of polymer science for CO 2 capture and utilization. In this work, a series of porous hyper-crosslinked ionic polymers (PIPs) with high surface area and abundant catalytic central units have been synthesized by a simple post-crosslinking of ionic liquid monomer and 4,4′-bis(chloromethyl)-1,1′-biphenyl. The prepared PIPs were used for CO 2 adsorption, and their adsorption capacity for CO 2 exceeded 100 mg g −1 at 273 K and 1.0 bar. Furthermore, the isotherm adsorption data of CO 2 were fitted respectively by Langmuir, Freundlich, Redlich-Peterson, and Toth isotherm models to calculate the thermodynamic parameters, including changes in Gibbs free energy (Δ G° ), enthalpy (Δ H° ), entropy (Δ S° ), and isosteric heat of adsorption (Δ H Isosteric ). It is concluded that the adsorption process of CO 2 on PIP is a spontaneous physical process. These PIP can also be used as heterogeneous catalysts for the cycloaddition of CO 2 with epoxides under metal/solvent/cocatalyst-free conditions. The excellent yields (up to 99%) of cyclic carbonates are ascribable to synergistic contributions of abundant microporous and active ionic catalytic centers. This study provides a new idea for developing functionalized ionic polymers that combine capture and conversion of CO 2 . • Postcrosslinking strategy to construct the porous ionic polymers (PIPs) for effective CO 2 capture and conversion. • Four isotherm model fitting and thermodynamic calculation of CO 2 adsorption by PIPs. • Excellent yields of cyclic carbonates are obtained for varied substrates under metal/solvent/co-catalyst-free conditions. • There was no significant decrease in cyclic carbonate yields after eight cycles of PIPs.