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Interface engineering breaks both stability and activity limits of RuO₂ for sustainable water oxidation.

ABSTRACT: Designing catalytic materials with enhanced stability and activity is crucial for sustainable electrochemical energy technologies. RuO₂ is the most active material for oxygen evolution reaction (OER) in electrolysers aiming at producing 'green' hydrogen, however it encounters critical electrochemical oxidation and dissolution issues during reaction. It remains a grand challenge to achieve stable and active RuO₂ electrocatalyst as the current strategies usually enhance one of the two properties at the expense of the other. Here, we report breaking the stability and activity limits of RuO₂ in neutral and alkaline environments by constructing a RuO₂/CoO_x interface. We demonstrate that RuO₂ can be greatly stabilized on the CoO_x substrate to exceed the Pourbaix stability limit of bulk RuO₂. This is realized by the preferential oxidation of CoO_x during OER and the electron gain of RuO₂ through the interface. Besides, a highly active Ru/Co dual-atom site can be generated around the RuO₂/CoO_x interface to synergistically adsorb the oxygen intermediates, leading to a favourable reaction path. The as-designed RuO₂/CoO_x catalyst provides an avenue to achieve stable and active materials for sustainable electrochemical energy technologies.

SUBMITTER: Du K

PROVIDER: S-EPMC9481627 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature

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Interface engineering breaks both stability and activity limits of RuO2 for sustainable water oxidation.

Du Kun K Zhang Lifu L Shan Jieqiong J Guo Jiaxin J Mao Jing J Yang Chueh-Cheng CC Wang Chia-Hsin CH Hu Zhenpeng Z Ling Tao T

Nature communications 20220916 1

Designing catalytic materials with enhanced stability and activity is crucial for sustainable electrochemical energy technologies. RuO2 is the most active material for oxygen evolution reaction (OER) in electrolysers aiming at producing 'green' hydrogen, however it encounters critical electrochemical oxidation and dissolution issues during reaction. It remains a grand challenge to achieve stable and active RuO2 electrocatalyst as the current strategies usually enhance one o ...[more]

PMID: 36114207

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Project description:HighlightsThree-dimensional (3D) core-shell heterostructured NixSy@MnOxHy nanorods grown on nickel foam (NixSy@MnOxHy/NF) were successfully fabricated via a simple hydrothermal reaction and a subsequent electrodeposition process. The fabricated NixSy@MnOxHy/NF shows outstanding bifunctional activity and stability for hydrogen evolution reaction and oxygen evolution reaction, as well as overall-water-splitting performance. The main origins are the interface engineering of NixSy@MnOxHy, the shell-protection characteristic of MnOxHy, and the 3D open nanorod structure, which remarkably endow the electrocatalyst with high activity and stability. Exploring highly active and stable transition metal-based bifunctional electrocatalysts has recently attracted extensive research interests for achieving high inherent activity, abundant exposed active sites, rapid mass transfer, and strong structure stability for overall water splitting. Herein, an interface engineering coupled with shell-protection strategy was applied to construct three-dimensional (3D) core-shell NixSy@MnOxHy heterostructure nanorods grown on nickel foam (NixSy@MnOxHy/NF) as a bifunctional electrocatalyst. NixSy@MnOxHy/NF was synthesized via a facile hydrothermal reaction followed by an electrodeposition process. The X-ray absorption fine structure spectra reveal that abundant Mn-S bonds connect the heterostructure interfaces of NixSy@MnOxHy, leading to a strong electronic interaction, which improves the intrinsic activities of hydrogen evolution reaction and oxygen evolution reaction (OER). Besides, as an efficient protective shell, the MnOxHy dramatically inhibits the electrochemical corrosion of the electrocatalyst at high current densities, which remarkably enhances the stability at high potentials. Furthermore, the 3D nanorod structure not only exposes enriched active sites, but also accelerates the electrolyte diffusion and bubble desorption. Therefore, NixSy@MnOxHy/NF exhibits exceptional bifunctional activity and stability for overall water splitting, with low overpotentials of 326 and 356 mV for OER at 100 and 500 mA cm-2, respectively, along with high stability of 150 h at 100 mA cm-2. Furthermore, for overall water splitting, it presents a low cell voltage of 1.529 V at 10 mA cm-2, accompanied by excellent stability at 100 mA cm-2 for 100 h. This work sheds a light on exploring highly active and stable bifunctional electrocatalysts by the interface engineering coupled with shell-protection strategy.

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Interface engineering breaks both stability and activity limits of RuO₂ for sustainable water oxidation.

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Interface engineering breaks both stability and activity limits of RuO<sub>2</sub> for sustainable water oxidation.

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