Tuning the Ni-Oxide Layer Structure on NiFe Alloys for High Oxygen Evolution Reaction Activity

Improvements in the catalyst performance for oxygen evolution reaction (OER) are essential to lower the kinetic barriers and energy losses associated with large-scale water electrolysis for hydrogen production. Surface amorphization has emerged as a promising catalyst strategy for enhancing OER performance. Here, an impregnation approach is used to construct an amorphous oxide phase with high oxidation states of Ni species on the surface of NiFe alloy. Benefiting from the ideal adsorption and enhanced conversion of oxygen intermediates along with electron transfer, the obtained catalyst shows a remarkable advance in OER mass activity in alkaline media, more than six and two times higher than that of conventional NiFe oxide and commercial Ir oxide catalysts, respectively. The dissolution of Fe species is also suppressed, preventing catalyst degradation and the adverse effects of peroxide decomposition. The high OER performance, peroxide-immunity, cost-effectiveness, and scalability make it a game-changer for large-scale alkaline water electrolysis.