Disrupting Interfacial Hydrogen-Bonding Networks via Dynamic Reconstruction Strategy for Enhanced CO2-to-C2+ Electrocatalysis

The morphology and microenvironment of ion-conducting polymers (ionomers) on the catalyst electrode surface critically govern the CO2 electrocatalytic performance. Herein, we report a dual-reconstruction strategy that synergistically tailors the surface structure of the Nafion ionomer using positively charged molecules and solvent effect. By combining a low-dielectric-constant solvent (isopropanol) with arginine cations, the optimized electrode achieves an 83.6% Faradaic efficiency for multicarbon (C2+) products at a high current density of –500 mA cm–2 in 1 M KOH. Based on experimental characterization and MD simulations, we propose a structural model in which the Nafion side chains are oriented away from both the catalyst surface and the electrolyte phase. In situ spectroscopic analyses, theoretical calculation, and experimental evidence suggest that this structural reorganization disrupts the interfacial hydrogen-bonding network, suppresses the competing hydrogen evolution reaction, improves effective gaseous CO2 accessibility, and facilitates C–C coupling along an energetically favorable *OC–COH pathway. This work provides valuable insights into microenvironment engineering of ionomer–catalyst interfaces for efficient CO2 electrolysis.