Suppressing the lattice oxygen diffusion via high-entropy oxide construction towards stabilized acidic water oxidation

The scale-up deployment of ruthenium (Ru)-based oxygen evolution reaction (OER) electrocatalysts in proton exchange membrane water electrolysis (PEMWE) is greatly restricted by the poor stability. As the lattice-oxygen-mediated mechanism (LOM) has been identified as the major contributor to the fast performance degradation, impeding lattice oxygen diffusion to inhibit lattice oxygen participation is imperative, yet remains challenging due to the lack of efficient approaches. Herein, we strategically regulate the bonding nature of Ru–O towards suppressed LOM via Ru-based high-entropy oxide (HEO) construction. The lattice disorder in HEOs is believed to increase migration energy barrier of lattice oxygen. As a result, the screened Ti₂₃Nb₉Hf₁₃W₁₂Ru₄₃O_x exhibits 11.7 times slower lattice oxygen diffusion rate, 84% reduction in LOM ratio, and 29 times lifespan extension compared with the state-of-the-art RuO₂ catalyst. Our work opens up a feasible avenue to constructing stabilized Ru-based OER catalysts towards scalable application.