Illustration of the Intrinsic Mechanism of Reconstructed Cu Clusters for Enhanced CO<sub>2</sub> Electroreduction to Ethanol Production with Industrial Current Density.

Zang, Yipeng; Wang, Shuo; Sang, Jiaqi; Wei, Pengfei; Zhang, Xiaomin; Wang, Qi; Wang, Guoxiong · Nano Lett · 2024

basic_science · Level V

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Abstract

Copper-based catalysts have been attracting increasing attention for CO<sub>2</sub> electroreduction into value-added multicarbon chemicals. However, most Cu-based catalysts are designed for ethylene production, while ethanol production with high Faradaic efficiency at high current density still remains a great challenge. Herein, Cu clusters supported on single-atom Cu dispersed nitrogen-doped carbon (Cu<sub><i>x</i></sub>/Cu-N/C) show ethanol Faradaic efficiency of ∼40% and partial current density of ∼350 mA cm<sup>-2</sup>. Quasi <i>in situ</i> X-ray photoelectron spectroscopy and operando X-ray absorption spectroscopy results suggest the generation of surface asymmetrical sites of Cu<sup>+</sup> and Cu<sup>0</sup> as well as Cu clusters by electrochemical reduction and reconstruction during the CO<sub>2</sub> electroreduction process. Density functional theory calculations indicate that the interaction between Cu clusters and the Cu-N/C support enhances *CO adsorption, facilitates the C-C coupling step, and favors the hydrogenation rather than dehydroxylation of the critical intermediate *CHCOH toward ethanol in the bifurcation.