Diamide-linked imidazolyl Poly(dicationic ionic liquid)s for the conversion of CO2 to cyclic carbonates under ambient pressure

[Display omitted] •High-density ionic active centers (2.014–4.883 mmol g-1) and hydrogen-bond donors (HBDs) were integrated into diamide-linked PIMDILs (PMAIL-x and PBAIL-2) catalysts successfully.•The interfacial synergistic effects between the diamide HBDs and high-density ionic active centers promotes the CO2 conversion under ambient pressure.•The formation of hydrogen bonds at the catalytic reaction interface can effectively activate CO2 and epoxides substrates.•PMAIL-2 possesses the highest catalytic activity, which can convert various epoxides into cyclic carbonates in excellent yields and selectivity (>99 %). The ionic active centers and hydrogen-bond donors (HBDs) in heterogeneous catalytic materials are highly beneficial for enhancing the interaction between solid–liquid-gas three-phase interfaces and promoting effective fixation of carbon dioxide (CO2). Diamide-linked imidazolyl poly(dicationic ionic liquid)s catalysts PIMDILs (PMAIL-x and PBAIL-2) were synthesized through the copolymerization of diamide-linked imidazolyl dicationic ionic liquids (IMDILs) with divinylbenzene (DVB), which successfully enable the simultaneous construction of high-density and uniformly distributed ionic active centers (2.014–4.883 mmol g−1) and hydrogen-bond donors (HBDs). The as-synthesized PIMDILs present excellent catalytic activity in promoting the cycloaddition of CO2 with epoxides. PMAIL-2 could convert epichlorohydrin (ECH) with a quantitative conversion of 99.8 % (selectivity > 99 %) under ambient pressure. Furthermore, only a decrease in activity of 5 % was observed even after six cycles of recycling. The excellent conversions (>97.3 %) were achieved for various terminal substituted epoxides. The experimental and characterization results reveal that the high-density ionic active centers and amide HBDs can effectively activate the reaction substrates, their synergistic effect plays a crucial role at the catalyst interface. This work is expected to provide some useful insights for the rational construction of heterogeneous catalysts for CO2 conversion.