Sustainable oxygen evolution electrocatalysis in aqueous 1 M H<sub>2</sub>SO<sub>4</sub> with earth abundant nanostructured Co<sub>3</sub>O<sub>4</sub>.

Yu, Jiahao; Garcés-Pineda, Felipe A; González-Cobos, Jesús; Peña-Díaz, Marina; Rogero, Celia; Giménez, Sixto; Spadaro, Maria Chiara; Arbiol, Jordi et al. · Nat Commun · 2022

basic_science · Level V

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Abstract

Earth-abundant electrocatalysts for the oxygen evolution reaction (OER) able to work in acidic working conditions are elusive. While many first-row transition metal oxides are competitive in alkaline media, most of them just dissolve or become inactive at high proton concentrations where hydrogen evolution is preferred. Only noble-metal catalysts, such as IrO<sub>2</sub>, are fast and stable enough in acidic media. Herein, we report the excellent activity and long-term stability of Co<sub>3</sub>O<sub>4</sub>-based anodes in 1 M H<sub>2</sub>SO<sub>4</sub> (pH 0.1) when processed in a partially hydrophobic carbon-based protecting matrix. These Co<sub>3</sub>O<sub>4</sub>@C composites reliably drive O<sub>2</sub> evolution a 10 mA cm<sup>-2</sup> current density for >40 h without appearance of performance fatigue, successfully passing benchmarking protocols without incorporating noble metals. Our strategy opens an alternative venue towards fast, energy efficient acid-media water oxidation electrodes.