Strategies for the design of ruthenium-based electrocatalysts toward acidic oxygen evolution reaction

Abstract

Polymer electrolyte membrane water electrolyzers (PEMWEs) driven by renewable electricity are deemed to be a promising technology toward green hydrogen production, where anodic oxygen evolution reaction (OER) is one of the main obstacles that impede the practical application of PEMWEs. The strongly acidic environment and greatly oxidative working conditions make the development of highly active and stable electrocatalysts toward OER extremely challenging. Ruthenium (Ru)-based materials as acidic OER catalysts possess a number of advantages including high activity and the lowest price among the precious metal family, while their long-term durability is far from satisfactory. To date, effective efforts have been made to improve the durability of Ru species to balance activity and stability. In this review, the recent progress in the development of Ru-based catalysts for enhanced acidic OER performance is summarized, expecting to offer guidance for exploring highly active and stable Ru-based catalysts. The fundamental understanding of the relationship between OER mechanism and activity as well as stability of Ru species is discussed. Then, experimental attempts to improve the acidic OER performance of Ru-based catalysts are reviewed. Finally, the challenges and perspectives for future studies of Ru-based catalysts for acidic OER are also proposed.