Interfacial Water on Ag/Ag ₂ S Nanowires Enhancing the Ethanol Selectivity for CO ₂ Electroreduction

Abstract

Abstract The electrochemical conversion of CO 2 into multicarbon products represents a pivotal yet challenging target, particularly for metal catalysts that predominantly yield C 1 products. Herein, this challenge is addressed through sulfur‐induced electronic modulation of Ag‐based catalysts, steering the CO 2 reduction pathway toward ethanol production. By constructing atomically engineered Ag/Ag 2 S nanowires (NWs) via a controlled sulfurization strategy, a remarkable Faradaic efficiency (FE) of 75% for ethanol at −0.95 V, along with exceptional stability over 14 h of high‐performance metrics surpassing most reported Ag‐based systems is achieved. Operando electrochemical surface‐enhanced Raman spectroscopy (EC‐SERS) and density functional theory (DFT) calculations unveil that the Ag/Ag 2 S heterointerface synergistically regulates interfacial water networks and stabilizes key * CO intermediates, thereby accelerating CO 2 activation, proton‐coupled electron transfer, and asymmetric C‐C coupling. Furthermore, sulfurization‐induced dual effects‐optimized hydrogen‐bond interactions and enriched K⁺ confinement are identified as critical drivers for tailoring the local microenvironment to favor ethanol selectivity. This work not only demonstrates a rational atomic interface design for C 2 product orientation but also deciphers the dynamic interplay between catalyst electronic structure and interfacial species, offering a molecular‐level roadmap for advanced CO 2 conversion systems.