Nanostructured Rhenium–Carbon Composites as Hydrogen-Evolving Catalysts Effective over the Entire pH Range

In addition to platinum (Pt), many metals (e.g., Ru, Co, Mo, Ni, W, and Fe) and their complexes have been explored as catalysts for a hydrogen evolution reaction (HER). Although the position of relatively inexpensive rhenium (Re) on the so-called Sabatier plot suggests its usefulness in HER, the performance of Re catalysts have, so far, been quite disappointing. The present work describes synthesis and characterization of clusters comprised of rhenium nanoparticles held together by an amorphous-carbon phase. Unlike standard HER catalysts, these Re/C clusters are characterized by small overpotantials and Tafel slopes not only under acidic but also neutral and basic conditions. In addition, they exhibit excellent durability over the entire pH range.