A Bifunctional UiO-66 Platform Enabled by Schiff-Base Engineering for CO2 Conversion and Epoxide-Anhydride Copolymerization.

In this study, we report a series of bifunctional UiO-66-based metal-organic framework (MOF) catalysts, functionalized with Schiff-base ligands and coordinated with divalent metal ions (M = Zn, Cu, Ni), for the sustainable transformation of epoxides via ring-opening copolymerization (ROCOP) with anhydrides and coupling with CO2. The rational integration of Lewis acidic metal centers and tunable porosity within the UiO-66 framework enables enhanced catalytic activity and selectivity. These catalysts achieve high conversions and excellent selectivity toward polyesters and cyclic carbonates under mild conditions (80°C for CO2 coupling; 110°C for ROCOP), with minimal by-products. Importantly, the catalysts exhibit robust recyclability, maintaining structural integrity and performance over multiple cycles. This work demonstrates a versatile and durable MOF platform for green polymerization and CO2 valorization, aligning with principles of sustainable catalysis and circular carbon utilization.