Construction of core-shell MOFs@ionic liquid materials and their performance for CO₂ cycloaddition reaction under atmospheric pressure

A flexible polymer (DP) was prepared by in-situ covalent assembly of dual-amino-functionalized ionic liquids and terephthalaldehyde. A core-shell composite (MIL-101@DP) was constructed by coating DP on the surface of metal-organic frame material MIL-101 (Cr) by post-synthesis modification, and was applied to catalyze the cycloaddition reaction of CO₂ and epichlorohydrin (ECH). MIL-101@DP retains the advantage of high specific surface area and high porosity of MIL-101 (Cr), and combines the nucleophilic site Cl⁻ and Lewis acidic site Cr^{3 +} . Under the synergistic interaction of Lewis acid sites and Lewis base sites, MIL-101@DP could efficiently catalyze activity the conversion of CO₂ and ECH reaction (ECH conversion rate can reach 99%) at atmospheric pressure, 80 ℃, 24 h and without cocatalyst. The activity did not decrease significantly after four cycles.