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

Developing efficient electrocatalysts for selective CO₂-to-C₂₊ 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 C₂₊ 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 CO₂ reduction electrocatalysts.