Well-Defined Ru Nanoclusters Anchored on Carbon: Facile Synthesis and High Electrochemical Activity toward Alkaline Water Splitting

Developing efficient and affordable alternatives for Pt-based electrocatalysts to promote the procedure of hydrogen evolution reaction (HER) is of significant importance. Herein, a facile and convenient strategy using tris(2,2′-bipyridyl)ruthenium(II) chloride hexahydrate as precursor is developed for synthesizing ultrafine and highly dispersed ruthenium nanoclusters on carbon support. It is discovered that the preadsorption of Ru precursor on carbon substrate and followed by pyrolysis are very crucial for the synthesis of such Ru nanoclusters. Among as-prepared samples, Ru/CN-800 shows the best HER electrocatalytic performance in alkaline solution, which outperforms the benchmark Pt/C and recently reported catalysts. The excellent performance of Ru/CN-800 was presumably attributed to the dominant metallic Ru as well as the ultrasmall Ru nanoclusters with a satisfied dispersion, which provides the massive highly active sites for HER. This facile and environmental-friendly pathway for synthesis of ultrasmall Ru nanoclusters with high HER activity shows a promise in practical applications.