SrO‐Induced Local Alkaline Microenvironment for Enhanced CO 2 Electroreduction to C 2 Products

ABSTRACT Electrocatalytic CO 2 reduction has emerged as a promising pathway toward carbon neutrality, with C 2 products attracting considerable interest due to their high economic value. However, the efficiency and selectivity of this process are limited by the high kinetic barrier of C─C coupling and strong competition from the hydrogen evolution reaction (HER). In this work, we propose a strategy to promote C─C coupling by constructing a local alkaline microenvironment and accordingly design and fabricate a heterojunction catalyst composed of SrO‐modified CuO (SrO/CuO). In‐depth investigations reveal that the incorporation of SrO enhances * CO intermediate coverage, facilitates the hydrogenation of * CO to * CHO, and promotes the subsequent asymmetric * CHO─ * CO coupling. More critically, SrO functions as an efficient water‐dissociation center, generating an OH − ‐enriched local microenvironment. This alkaline setting not only suppresses the competing HER but also stabilizes the C─C coupling transition state ( * CHO─ * CO) and provides ample * H to accelerate * CO hydrogenation, thereby greatly enhancing selective C 2 production. Electrochemical tests demonstrate that SrO/CuO achieves a high C 2 Faradaic efficiency of 71.4% at −1.5 V vs. RHE in a flow cell, while maintaining excellent stability over a wide potential window.