Modulating adsorbed hydrogen drives electrochemical CO<sub>2</sub>-to-C<sub>2</sub> products.

Feng, Jiaqi; Zhang, Libing; Liu, Shoujie; Xu, Liang; Ma, Xiaodong; Tan, Xingxing; Wu, Limin; Qian, Qingli et al. · Nat Commun · 2023

basic_science · Level V

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Abstract

Electrocatalytic CO<sub>2</sub> reduction is a typical reaction involving two reactants (CO<sub>2</sub> and H<sub>2</sub>O). However, the role of H<sub>2</sub>O dissociation, which provides active *H species to multiple protonation steps, is usually overlooked. Herein, we construct a dual-active sites catalyst comprising atomic Cu sites and Cu nanoparticles supported on N-doped carbon matrix. Efficient electrosynthesis of multi-carbon products is achieved with Faradaic efficiency approaching 75.4% with a partial current density of 289.2 mA cm<sup>-2</sup> at -0.6 V. Experimental and theoretical studies reveal that Cu nanoparticles facilitate the C-C coupling step through *CHO dimerization, while the atomic Cu sites boost H<sub>2</sub>O dissociation to form *H. The generated *H migrate to Cu nanoparticles and modulate the *H coverage on Cu NPs, and thus promote *CO-to-*CHO. The dual-active sites effect of Cu single-sites and Cu nanoparticles gives rise to the catalytic performance.