Local microenvironment modulation in Cu(I)‐carbon covalent metal–organic frameworks for highly efficient CO ₂ conversion

Introducing defects into metal–organic frameworks (MOFs) offers a powerful strategy to tune their local microenvironments and boost catalytic performance. Herein, we report a “truncated linker” approach to construct defect‐engineered Cu(I)‐carbon covalent bonded frameworks (dMOF‐ x %PA). Using propargylamine as a chain‐terminating monomer, we deliberately create missing‐linker defects, which not only tune the porosity but also introduce additional Lewis basic (–NH 2 ) sites and improve the accessibility of Cu(I) active centers. The optimized TEPT‐dMOF‐30%PA exhibits exceptional activity in the carboxylation of terminal alkynes using atmospheric‐pressure CO 2 . Under mild conditions (80°C, 0.1 MPa, 6 h), it achieves a 96% yield of phenylpropiolic acid, outperforming both its defect‐free counterpart and most reported heterogeneous catalysts. Moreover, the catalyst shows excellent recyclability and structural stability. Combined in situ fourier‑transform infrared spectroscopy (FT‐IR) spectroscopy and density functional theory (DFT) calculations reveal a synergistic catalytic mechanism. This work establishes a general paradigm for designing robust, defect‐engineered MOFs with tailored microenvironments for efficient and sustainable CO 2 conversion.