Novel engineering of ruthenium‐based electrocatalysts for acidic water oxidation: A mini review

The oxygen evolution reaction (OER) is pivotally involved in proton exchange membrane water electrolyzers (PEMWEs). However, the commercialized iridium‐based catalysts often suffer from severe sluggish kinetics, eventually deteriorating the polarization and overall PEMWEs performance. Therefore, to develop OER electrocatalysts with promising reaction kinetics and high stability is of great significance for PEMWEs. Compared to iridium, the ruthenium‐based catalysts possess lower price and higher activity in acidic water oxidation, which promises Ru‐based materials to replace the state‐of‐the‐art IrOx. Yet, the less stable ruthenium than iridium impedes its real applications. In this mini review, recent knowledge of feasible engineering strategies for migrating the Ru‐based electrocatalysts' stability is summarized. In order to improve performance and durability, basic fundamentals of acidic OER on nanoscale and molecular engineered Ru‐based electrocatalysts are briefly introduced. In the end, the challenges and outlook for engineering novel Ru‐based electrocatalysts are presented. Designing feasible engineering strategies to migrate the ruthenium‐based electrocatalysts' stability is of great importance for advancing the oxygen evolution reaction in proton exchange membrane water electrolyzers. In order to improve the performance and durability, basic reaction fundamentals and molecular engineering of ruthenium‐based electrocatalysts are systematically summarized in this review, as well as their future challenges and outlook.