Electrocatalytic C─S Cross‐Coupling via Engineered Frustrated Lewis Acid‐Base Pairs for High‐Efficiency Methanesulfonate Synthesis

Abstract The electrochemical synthesis of sulfonyl compounds under mild conditions remains a significant challenge due to the reliance on harsh reagents, high energy consumption, and low selectivity in conventional methods. Herein, we report a novel strategy for efficient C─S bond formation through in situ modulation of frustrated Lewis acid‐base pairs within a copper‐based metal‐organic framework (CuBDC‐XN). By precisely engineering electron‐deficient Cu Lewis acid sites and electron‐rich XN‐functionalized Lewis base sites, this bifunctional catalyst enables the synergistic co‐reduction of SO 3 2− and CO 2 into methanesulfonate (MS) at ambient conditions with a Faradaic efficiency of 13.77% (−0.78 V versus RHE). Mechanistic studies reveal that the frustrated Lewis pairs selectively stabilize key intermediates (*CHO and SO 3 2− ) via electrostatic interactions, facilitating nucleophilic attack and C─S coupling with a reduced energy barrier (0.48 eV). In situ spectroscopic analyses and DFT calculations further elucidate the dynamic adsorption‐configuration regulation and intermediate evolution pathway. This work not only establishes a molecular‐level understanding of cooperative Lewis acid‐base catalysis but also provides a universal design principle for the sustainable electrosynthesis of value‐added organosulfur compounds.