Lewis Acid-Base Pairing in Imidazolium IL/Br-ZIF-L: A Breakthrough in Low-Pressure CO₂ Cycloaddition

The development of efficient metal-organic framework (MOF)-based catalysts for converting CO₂ into value-added chemicals via epoxide activation remains both scientifically and technically challenging. This study presents an imidazolium-based ionic liquid/MOF (IL/MOF) composite with precisely controlled porosity, achieved through an IL soft-template strategy that optimizes the pore structure by regulating MOF crystal growth. This structural enhancement significantly improves CO₂ and epoxide adsorption/activation capabilities. It is worth noting that under mild conditions (80 °C and atmospheric CO₂ pressure), the composite material achieves a cyclic carbonate yield of 95.7% and exhibits certain recyclability (up to 6 cycles). Even in simulated flue gas (15% CO₂), it maintains 99% CO₂ selectivity after 16 h.The synergistic catalytic system, comprising Zn Lewis acid sites, Br^- nucleophiles from IL, and imidazole-derived Lewis basic environments, effectively activates both epoxides and CO₂. This work establishes a strategic approach for synthesizing IL/MOF catalysts that enable efficient atmospheric-pressure conversion of CO₂ into value-added chemicals.