Ruthenium and Iron Co-doped Molybdenum Carbide as a Stable Hydrogen Evolution Electrocatalyst in Harsh Electrolyte

Electrocatalytic water splitting is one of the most commercially valuable pathways of hydrogen production especially combined with renewable electricity; however, efficient and durable electrocatalysts are urgently needed to reduce electric energy consumption. Here, we reported a Ru and Fe co-doped Mo₂ C on nitrogen doped carbon via a controllable two-step method, which can be used for efficient and enduring hydrogen evolution reaction. At 10, 100 and 200 mA cm^-2 in acidic electrolyte, the resultant Ru-Fe/Mo₂ C@NC delivered low overpotentials of 31, 78 and 103 mV, respectively, which are comparable to that of the commercial Pt/C (20 wt %). At an applied current density of 100 mA cm^-2 , stable hydrogen production was conducted for 120 h without obvious degradation. In alkaline media, Ru-Fe/Mo₂ C@NC can also deliver a current density of 100 mA cm^-2 for more than 100 h. Furthermore, the Ru-Fe/Mo₂ C@NC electrocatalyst was used as cathode in an anion exchange membrane water electrolyzer under industrial environments for robust hydrogen production. The characterization and electrochemical results prove the synergism effects between Ru, Fe dopants and Mo₂ C for promoting hydrogen evolution activity. This work would pave a new avenue to fabricate low-cost, high-performance hydrogen evolution electrocatalysts for industrial water electrolyzers.