Scalable ampere-level CO<sub>2</sub> electroreduction to ethylene enabled by descriptor-guided oxygen affinity engineering.

Huang, Bing; Wang, Ke; Wang, Chentao; Yan, Mi; Li, Zhenglong; Xie, Pengfei · Nat Commun · 2026

basic_science · Level V

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Abstract

The electroreduction of CO<sub>2</sub> to ethylene using renewable electricity offers a sustainable approach for greenhouse gas mitigation. However, the efficient ethylene production is challenged by sluggish C-C coupling and wide product distribution. Guided the energy changes associated with C-C coupling and C-O cleavage as descriptors for ethylene electrosynthesis, we predict and synthesize unsaturated MgO<sub>1-x</sub> anchored on Cu via an electrochemical-induced phase separation method. Electrochemical evaluation of this catalyst achieves an ethylene Faradaic efficiency of 78.2% at 300 mA cm<sup>-2</sup> in a flow cell. Mechanism studies reveal the bifunctionality of MgO<sub>1-x</sub>. On one side, chemical interaction of MgO<sub>1-x</sub> with Cu domain stabilizes Cu<sup>+</sup> and gives asymmetric Cu<sup>+</sup>···Cu<sup>0</sup> pairs, facilitating the *CO-CHO coupling. On another side, the MgO<sub>1-x</sub> with high oxygen affinity strengthens the binding with dual-carbon intermediate and promotes the C-O bond dissociation, accelerating ethylene formation. Ultimately, this catalyst delivers 60.7% ethylene selectivity at 25 A in membrane electrode assembly of 100 cm<sup>2</sup>, equivalent to a C<sub>2</sub>H<sub>4</sub> production rate of 1.1 L h<sup>-1</sup>.