Recent research progress on ruthenium-based catalysts at full pH conditions for the hydrogen evolution reaction

Hydrogen is considered a key renewable energy source to meet future energy needs, and the accelerated development of hydrogen energy is largely dependent on the cost-effective and efficient production of hydrogen. Nowadays, the production of hydrogen by electrolyzing water is a generation of clean energy with great potential for development, but its industrialization requires the search for cheap and efficient catalysts. Platinum (Pt) is currently regarded as the most effective catalyst for the production of hydrogen from electrolytic water. However, its high price and scarcity limit its scale up, so the search for cheap and efficient catalysts has become a hot research topic. Nowadays, various noble/non-precious and metal-free catalysts have been developed for hydrogen evolution processes, among which ruthenium (Ru) catalysts are recognized as a promising material for hydrogen production from electrolytic water because they make a better balance between performance and price. In this review, we summarized the reported ruthenium-based catalysts with excellent hydrogen evolution reaction (HER) activity, specifically, Ru with carbon supports, Ru phosphide-based catalysts, and Ru catalysts on other metals. Finally, we discussed challenges and prospects for the development of Ru-based catalysts in the field of HER research.