OXYGEN EVOLUTION REACTION ON COMPOSITE COBALT BORIDES.

The oxygen evolution reaction on cobalt borides and composite cobalt borides was investigated in a 6 m KOH solution (1 m equals 1 mol dm** minus **3) using the factor of the magnetic properties. In the system of cobalt borides (Co:B equals 3:1) prepared at various sintering temperatures, the boride having a higher saturation magnetization revealed a higher activity of the oxygen evolution reaction. In the system of composite cobalt borides which have various magnetic moments, mu //B, a clear correlation between the activity of the oxygen evolution reaction and the saturation magnetization (or magnetic moment, mu //B) was observed for several composite cobalt boride species (i. e. , Co-Fe-B, Co-Ni-B, Co-Mn-B, and Co-B). Among the composite cobalt boride species, the cobalt iron boride (Co:Fe:B equals 1:2:1) sintered at 450 degree C showed the highest activity of oxygen evolution reaction in a 6 m KOH solution.