Highly Stable Layered Coordination Polymer Electrocatalyst toward Efficient CO₂-to-CH₄ Conversion

Cu²⁺-based materials, a class of promising catalysts for the electrocatalytic carbon dioxide reduction reaction (CO₂RR) to value-added chemicals, usually undergo inevitable and uncontrollable reorganization processes during the reaction, resulting in catalyst deactivation or the new active sites formation and bringing great challenges to exploring their structure–performance relationships. Herein, a facile strategy is reported for constructing Cu²⁺ and 3, 4-ethylenedioxythiophene (EDOT) coordination to stabilize Cu²⁺ ions to prepare a novel layered coordination polymer (CuPEDOT). CuPEDOT enables selective reduction of CO₂ to CH₄ with 62.7% Faradaic efficiency at the current density of 354 mA cm⁻² in a flow cell, and the catalyst is stable for at least 15 h. In situ spectroscopic characterization and theoretical calculations reveal that CuPEDOT catalyst can maintain the Cu²⁺-EDOT coordination structurally stable in CO₂RR and significantly promote the further hydrogenation of *CO intermediates, favoring the formation of CH₄ instead of dimerization to C₂ products. The strong coordination between EDOT and Cu²⁺ prevents the reduction of Cu²⁺ ions during CO₂RR. The finding of this work provides a new perspective on designing molecularly stable, highly active catalysts for CO₂RR.