Ligand-Engineered Rearrangement of Active Sites in Silver-Based MOFs for Improved CO₂ Capture

Precise regulation of the coordination environment of active sites to optimize the physicochemical structure, electronic configuration, and orbital hybridization mode of active species is the core strategy for enhancing catalytic performance. In this study, using methylthio group-containing terpyridine ligands as building blocks, three Ag-MOFs with different structures were successfully constructed by modifying substituent positions and ligand chain lengths to regulate Ag catalytic active sites. MOF-Ag1 exhibits a one-dimensional W-shaped structure, while MOF-Ag2, formed after shortening the chain length, has a two-dimensional planar structure. In contrast, MOF-Ag3, with precise regulation of substituent positions, breaks the limitation of one-dimensional structure and forms a unique two-dimensional ladder-like structure. Among them, MOF-Ag3 exhibits significantly enhanced CO₂ fixation performance, attributed to more fully exposed Ag active sites and their closer contact with the substrate. The study indicates that achieving optimized rearrangement of Ag catalytic sites through regulation of ligand structure is of great significance for improving the catalytic performance of Ag-MOFs, providing new strategies and theoretical references for the design of high-performance catalytic materials.