A Review on Highly Efficient Ru-Based Electrocatalysts for Acidic Oxygen Evolution Reaction

Proton exchange membrane water electrolysis (PEMWE) technology is seen as the most compatible hydrogen production technology with renewable energy generation. However, the sluggish kinetics of the anodic oxygen evolution reaction (OER) and the scarcity of acid-resistant, high-activity, and low-cost catalysts have seriously hindered the overall efficiency and manufacturing costs of PEMWE. Recently, ruthenium (Ru)-based materials have gradually attracted attention due to their suitable binding strength toward oxygen intermediates and lowest price in the noble metal family. Herein, the great achievements and progress of Ru-based acidic OER electrocatalysts are comprehensively reviewed, which started with a general description of reaction mechanisms and in situ characterization techniques to understand the structure-activity relationships. Subsequently, some typical strategies to enhance the activity and stability of Ru-based electrocatalysts are highlighted. Insights from synthesis methods, advanced characterizations, intermediate evolution, and theoretical calculations are provided, together with our viewpoints on the daunting challenges and future endeavors of Ru-based OER electrocatalysts for their practical employment.