Imidazolium-based ionic porous hybrid polymers with POSS-derived silanols for efficient heterogeneous catalytic CO2 conversion under mild conditions

Abstract

This work reports a new family of imidazolium-based ionic porous hybrid polymers (termed IM-iPHPs) with polyhedral oligomeric silsesquioxane (POSS)-derived silanols (SiOH) towards efficient catalytic conversion of carbon dioxide (CO2) under mild conditions. A series of IM-iPHPs are constructed by the Heck reaction between newly-designed bromobenzene-bearing imidazolium ionic monomers and octavinylsilsesquioxane under solvothermal conditions. The obtained IM-iPHPs possess high surface areas up to 464 m2 g−1 and large pore volumes up to 1.65 cm3 g−1, highly dispersed ionic active sites, and simultaneous with in-situ formed SiOH groups, which are regarded as metal-free heterogeneous catalysts for efficiently converting CO2 with various epoxides into cyclic carbonates under atmospheric pressure and low temperatures. Moreover, the catalyst can be easily reused with stable recyclability. The synergistic catalysis of hydrogen bond donors SiOH and Br− anions within hydrophobic micro-environment of the catalysts IM-iPHPs together contributed to the excellent catalytic performance.