Delocalization State‐Stabilized Znδ+ Active Sites for Highly Selective and Durable CO2 Electroreduction

Abstract Zinc (Zn)‐based materials are cost‐effective and promising single‐metal catalysts for CO 2 electroreduction to CO but is still challenged by low selectivity and long‐term stability. Undercoordinated Zn (Zn δ+ ) sites have been demonstrated to be powerful active centers with appropriate * COOH affinity for efficient CO production However, electrochemical reduction conditions generally cause the inevitable reduction of Zn δ+ , resulting in the decline of CO efficiency over prolonged operation. Herein, a Zn cyanamide (ZnNCN) catalyst is constructed for highly selective and durable CO 2 electroreduction, wherein the delocalized Zn d ‐electrons and resonant structure of cyanamide ligand prevent the self‐reduction of ZnNCN and maintain Zn δ+ sites under cathodic conditions. The mechanism studies based on density functional theory and operando spectroscopies indicate that delocalized Zn δ+ site can stabilize the key * COOH intermediate through hard–soft acid–base theory, therefore thermodynamically promoting CO 2 ‐to‐CO conversion. Consequently, ZnNCN delivers a CO Faradaic efficiency (FE) of up to 93.9% and further exhibits a remarkable stability lifespan of 96 h, representing a significant advancement in developing robust Zn‐based electrocatalysts. Beyond expanding the variety of CO 2 reduction catalysts, this work also offers insights into understanding the structure‐function sensitivity and controlling dynamic active sites.