Enhancing the coupling reaction between CO2 and epoxides over amino-functionalized defective-UiO-66

Abstract

Metal–organic frameworks (MOFs) demonstrate promising potential for CO₂ conversion, and defective MOFs show enhanced catalytic performance owing to exposed Lewis acid sites. Herein, we prepared amino-functionalized defective UiO-66-DABA_x (where x represents the molar percentage of 3,4-diaminobenzoic acid (DABA) relative to the total linker content) through a one-pot dual-ligand strategy, using 3,4-diaminobenzoic acid as both defect inducer and amino source. Controlled ligand defects generate abundant undercoordinated Zr⁴⁺ sites, while –NH₂ groups strengthen CO₂ adsorption and activation. The synergistic effect of Zr⁴⁺ and –NH₂ greatly promotes epoxide ring-opening and CO₂ transformation under mild, solvent-free conditions. UiO-66-DABA_0.2 exhibits high catalytic activity with 95% cyclic carbonate yield, low activation energy, and good recyclability. This work provides a feasible approach for designing multifunctional MOF catalysts for efficient CO₂ fixation.