Exploration of Gas-Dependent Self-Adaptive Reconstruction Behavior of CuO for Electrochemical CO Conversion to Multi-Carbon Products.

Structural reconstruction of electrocatalysts plays a pivotal role in catalytic performances for CO reduction reaction (CORR), whereas the behavior is by far superficially understood. Here, we report that CO accessibility results in a universal self-adaptive structural reconstruction from CuO to Cu@CuO composites, ending with feeding gas-dependent microstructures and catalytic performances. The CO-rich atmosphere favors reconstruction for CORR, whereas the CO-deficient one prefers that for hydrogen evolution reaction. With the assistance of spectroscopic analysis and theoretical calculations, we uncover a CO-induced passivation behavior by identifying a reduction-resistant but catalytic active Cu(I)-rich amorphous layer stabilized by *CO intermediates. Additionally, we find extra CO production is indispensable for the robust production of CH. An inverse correlation between durability and FE/FE is disclosed, suggesting that the self-stabilization process involving the absorption of *CO intermediates on Cu(I) sites is essential for durable electrolysis. Guided by this insight, we design hollow CuO nanospheres for durable and selective CORR electrolysis in producing CH. Our work recognizes the previously overlooked passivation reconstruction and self-stabilizing behavior and highlights the critical role of the local atmosphere in modulating reconstruction and catalytic processes.