Construction of an Amino-Functionalized Thorium MOF for Bifunctional Catalysis toward CO2 Cycloaddition and...

The catalytic conversion of CO2 into high-value chemicals serves as a pivotal strategy for sustainable carbon resource utilization, yet it is hindered by the thermodynamic stability and kinetic inertness of CO2. Herein, an amino-functionalized thorium-based metal-organic framework (NH2-Th-MOF) was solvothermally constructed using Th4+ nodes and 5-aminoisophthalate linkers, establishing a Lewis acid-base synergistic heterogeneous catalytic system. Benefiting from the cooperative effect between Lewis acidic Th4+ sites and pendant -NH2 groups, NH2-Th-MOF displays outstanding catalytic activity in two representative CO2 fixation reactions. Under solvent-free conditions, it realizes nearly quantitative cyclic carbonate yields in CO2 cycloaddition with epoxides; under room temperature and low CO2 pressure, it enables highly efficient reductive N-formylation of amines with CO2, achieving almost complete conversion, yield, and selectivity. Mechanistic investigations confirm the critical role of amino groups in enhancing catalytic performance, while in situ DRIFTS studies reveal that the acid-base synergistic microenvironment promotes substrate adsorption, CO2 activation, and intermediate transformation. This work expands the catalytic application scope of actinide-based MOFs and offers a rational design approach for developing multifunctional MOF catalysts toward efficient CO2 resource utilization.