Polymer Brush-Grafted Metal-Organic Framework Nanoplates for Enhanced Catalysis of CO₂ Cycloaddition with Epoxides

The catalytic performance of 2D nanostructure-based heterogeneous catalysts is highly dependent on their dispersibility and stability. This work presents the grafting of polymer brushes onto 2D Cu-based metal-organic framework (MOF) nanoplates via a versatile UV-induced radical polymerization approach for CO₂ fixation through the cycloaddition reaction with epoxides. The polymer brushes are selectively anchored to the external surfaces of the nanoplates, which greatly improves the long-term dispersibility and stability in solvents while preserving their intrinsic porosity and crystalline structures. The poly(N,N-dimethylaminoethyl methacrylate)-grafted 2-aminoterephthalic acid copper (CuBDC-NH₂@PDMAEMA) nanoplates, with an optimized polymer brush thickness, achieve a maximum yield of 81.2% in the cycloaddition of CO₂ with styrene oxide, which is a 1.6-fold improvement over that of the unmodified CuBDC-NH₂ nanoplates. The grafted nanoplates also exhibit excellent recyclability with a slight decrease in yield after multiple consecutive cycles. The versatility of this approach is further demonstrated by its application to other polymers and epoxide substrates, where polymer-grafted catalysts consistently outperform their pristine counterparts. Our strategy provides a feasible and efficient route to synthesize MOF/polymer hybrid nanomaterials for sustainable CO₂ utilization and green chemistry applications.