Atomically dispersed ruthenium in carbon aerogels as effective catalysts for pH-universal hydrogen evolution reaction

Development of cost-effective catalysts for hydrogen evolution reaction (HER) plays a significant role in scalable production of hydrogen. Herein, carbon aerogels doped with atomically isolated Ru are produced pyrolytically from biomass hydrogels and exhibit a remarkable performance in HER within a broad range of solution pH, due to the formation of abundant RuNx moieties. At the current density of 10 mA cm−2, the optimal sample (NCAG/Ru-3) exhibits an ultralow overpotential of merely −4 mV in 1.0 M KOH, −45 mV in 1.0 M phosphate buffer solution and −65 mV in 0.5 M H2SO4, with the respective mass activity 44, 16 and 6 times that of commercial Pt/C benchmark. The excellent performance is also manifested in full water splitting. Theoretical calculations suggest that the high activity arise from the RuNx sites at the zigzag edges and nanowrinkles. These results underscore the unique quality of carbon aerogel-based single atom catalysts in electrochemical energy technologies.