Nanodefect‐Stabilized Pd Nanoparticles on CuO Nanosheets Enable Efficient C 2+ Production in Electrochemical CO 2 Reduction

ABSTRACT Developing efficient electrocatalysts for selective CO 2 ‐to‐C 2+ conversion remains challenging due to the kinetic limitations of C–C coupling and catalyst stability issues. In this work, we report a nano‐defect‐stabilized approach where Pd nanoparticles are immobilized in electrochemically generated nanoscale pits on CuO nanosheets, forming a stable CuO−Pd interface. The optimized catalyst achieves 70.30% Faradaic efficiency for C 2+ products at −1.5 V versus RHE, outperforming bare CuO by over two‐fold, while maintaining stable performance over 17 h. In situ spectroscopic studies reveal that the Pd‐enhanced interface promotes CO coverage and stabilizes C–C coupling intermediates ( * COCO and * COCHO). Theoretical calculations validate that the Pd–Cu interaction facilitates CO adsorption and reduces the energy barrier for C–C coupling. This nano‐defect‐stabilized strategy, which utilizes in situ‐formed nano‐defects to stabilize active metal sites, provides a generalizable design strategy for developing robust bimetallic CO 2 reduction electrocatalysts.