Regulating basicity of porous poly(ionic liquid)s for CO2 fixation into dimethyl carbonate under mild condition

Direct carbon dioxide (CO2) conversion into valuable chemicals like dimethyl carbonate (DMC) is an atom efficient avenue for CO2 utilization but greatly challenges the catalyst designation because the requirement of multiple active sites. Herein, regulation of the basicity of porous poly(ionic liquid)s (PPILs) was reached by post-treating epoxy-functional precursor and utilizing 1,5,7-triazodicyclic [4.4.0] Dec-5-ene (TBD) to convert epoxy functional ionic moieties into the multifunctional sites with nucleophilic-leaving capable anions, hydroxyl group and TBD derived basic sites. The constructed catalyst was highly active in the one-pot and two-step DMC synthesis by coupling the CO2 cycloaddition with epoxide and successive transesterification. A high yield up to 93% was observed by using atmospheric CO2 under the metal-solvent-additive free condition. Stable reusability and extendibility by using multiple epoxides further reveal the efficiency and potentiality of the present catalyst in CO2 fixation.