Amorphous Cobalt Boride (Co 2 B) as a Highly Efficient Nonprecious Catalyst for Electrochemical Water Splitting: Oxygen and Hydrogen Evolution

It is demonstrated that amorphous cobalt boride (Co 2 B) prepared by the chemical reduction of CoCl 2 using NaBH 4 is an exceptionally efficient electrocatalyst for the oxygen evolution reaction (OER) in alkaline electrolytes and is simultaneously active for catalyzing the hydrogen evolution reaction (HER). The catalyst achieves a current density of 10 mA cm −2 at 1.61 V on an inert support and at 1.59 V when impregnated with nitrogen‐doped graphene. Stable performance is maintained at 10 mA cm −2 for at least 60 h. The optimized catalyst, Co 2 B annealed at 500 °C (Co 2 B‐500) evolves oxygen more efficiently than RuO 2 and IrO 2 , and its performance matches the best cobalt‐based catalysts reported to date.…

• DF
  Deutsche Forschungsgemeinschaft