Engineering Co-ion vacancy in dynamically reconstructed Co-based catalysts for practical anion-exchange membrane electrolysis.

Zhao, Jingxuan; Li, Xinmei; Wang, Kunjie; Hung, Yuan-Ting; Wang, Qing; Cui, Xingyu; Gao, Guanyin; Li, Xiangyang et al. · Nat Commun · 2026

basic_science · Level V

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Abstract

Precisely engineering metal-ion vacancy in dynamically reconstructed electrocatalysts provides an attractive symmetry-breaking tool to develop robust electrocatalysts under operation conditions. Herein, we demonstrate a convenient Sr-ion-mediated reconstruction strategy to fabricate Co-vacancy-enriched Sr-CoOOH nanosheets under oxygen evolution reaction conditions with balanced activation and refilling of lattice oxygen for practical anion-exchange membrane water electrolysis. The Sr-ion substitution in pre-catalysts can weaken bond strength for facilitated Co-ion vacancies formation in reconstructed oxyhydroxides. These Co-ion vacancies not only strengthen Co-O covalency for lattice oxygen activation, but also improve hydroxyl affinity for lattice oxygen refilling. The corresponding water electrolyzer exhibits a cutting-edge current of 3.3 A cm<sup>-</sup><sup>2</sup> at 2.0 V with a lowered energy consumption of 43.5 kWh kg<sup>-1</sup><sub>H2</sub>, and negligible degradation of 0.10 mV h<sup>-1</sup> for 1000 h. This work paves an enlightening guideline to finely engineer metal-ion vacancy in dynamically reconstructed electrocatalysts, demonstrating the feasibility to develop targeted catalysts under practical conditions.