The coupling between epoxide and carbon dioxide into cyclic carbonates in the absence of co-catalyst and solvents is a feasible strategy for removing CO2 from the atmosphere and achieving a carbon-neutral cycle. In this context, two new bifunctional catalytic systems prepared by modification metal–organic frameworks (MOFs) with ionic liquids (ILs) and catalytic activities have been compared in converting CO2 into cyclic carbonates. IL methylimidazolium bromide (MI-Br) is grafted into both ZnMOF-NH2 and Zn3(L)3(H2L) MOF to produce the dual-functional one-component systems with a high density of Lewis acidic Zn(II) metal sites and IL functional sites to carry out co-catalyst/solvent-free cycloaddition of CO2 to epoxides. The characteristics of the MI-Br IL@MOFs were revealed via different techniques, including FE-SEM, EDX, FT-IR, XRD, N2 adsorption, NH3-TPD, and ICP-OES. Further, two efficient catalysts act as excellent recyclable catalysts for 4 successive cycles without substantial loss in catalytic activity cycloaddition of CO2 to epoxides to cyclic carbonates. Herein, a synergistic catalytic mechanism between Lewis acidic sites and Br− ions is proposed to carry out the cycloaddition of CO2 to epoxides under co-catalyst/solvent-free conditions.

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