In situ probing the dynamic reconstruction of copper-zinc electrocatalysts for CO 2 reduction.

Unravelling the dynamic characterization of electrocatalysts during the electrochemical CO 2 reduction reaction (CO 2 RR) is a critical factor to improve the production efficiency and selectivity, since most pre-electrocatalysts undergo structural reconstruction and surface rearrangement under working conditions. Herein, a series of pre-electrocatalysts including CuO, ZnO and two different ratios of CuO/ZnO were systematically designed by a sputtering process to clarify the correlation of the dynamic characterization of Cu sites in the presence of Zn/ZnO and the product profile. The evidence provided by in situ X-ray absorption spectroscopy (XAS) indicated that appropriate Zn/ZnO levels could induce a variation in the coordination number of Cu sites via reversing Ostwald ripening. Specifically, the recrystallized Cu site with a lower coordination number exhibited a preferential production of methane (CH 4 ). More importantly, our findings provide a promising approach for the efficient production of CH 4 by in situ reconstructing Cu-based binary electrocatalysts.