Constructing Ag/Cu2O interface for efficient neutral CO2 electroreduction to C2H4

Abstract Neutral CO 2 electroreduction to multi‐carbons (C 2+ ) offers a promising pathway to reduce the CO 2 and energy losses originating from the carbonate formation. However, the sluggish kinetics of C−C coupling brings a significant challenge of achieving high selectivity of a single product (such as ethylene), especially at industrial‐relevant current densities (>300 mA cm −2 ). Here, we reported an optimized Ag‐Cu 2 O interfacial catalyst that exhibited C 2+ Faradaic efficiency (FE) of 73.6 % at 650 mA cm −2 in a flow cell. Remarkably, it obtained FE C2H4 of 66.0 % with a partial current density of 429.1 mA cm −2 , making it stand out among the reported Cu‐based electrocatalysts. In situ Raman spectra uncovered that the Ag/Cu 2 O interfaces enabled a high coverage of *CO around the partially reduced Cu + /Cu 0 active sites. Furthermore, theoretical calculations demonstrated the enhanced CO formation and C−C coupling at the Ag/Cu 2 O interface. This work reported an unprecedented neutral CO 2 electroreduction to C 2 H 4 performance and provided an in‐depth comprehension of the role of the bimetallic interface.