ScholarWorks@중앙대학교

초록

Electrocatalytic CO2 reduction has emerged as a promising pathway toward carbon neutrality, with C2 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 C2 production. Electrochemical tests demonstrate that SrO/CuO achieves a high C2 Faradaic efficiency of 71.4% at −1.5 V vs. RHE in a flow cell, while maintaining excellent stability over a wide potential window.

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