“One Stone, Two Birds”: Multi-Element Doping Induced Crystallinity Modulation for Large Current Density Oxygen Evolution Reaction

Abstract

Oxygen evolution reaction (OER) plays a critical role in water splitting, which can directly determine the energy consumption of hydrogen production. However, the poor stability of catalysts at large current density inhibits their industrial application. Therefore, the development of efficient catalysts with industry-relevant activities still faces great challenges. Herein, a one-step corrosion strategy is reported for the preparation of multi-element low-crystal transition metal hydroxide (denoted as NiFeCrMnCo-c). Density functional theory calculation indicates that multi-element doping strategy improves the conductivity of the catalyst and reduces the energy barrier in the catalytic process. Only 259 and 303 mV overpotentials are required to achieve the anodic current densities of 100 and 1000 mA cm⁻² respectively, and it can work at the anodic current density of 50 and 1000 mA cm⁻² for 300 h without apparent attenuation. Furthermore, when it is self-assembled as an anion exchange membrane electrolyzer, it requires only 1.72 V at 1000 mA cm⁻² for industrial water splitting and operates stably for 100 h at 60 °C, which can meet the requirements of industrial hydrogen production. The design of the OER catalysts with simple preparation, high activity, and high current density provides a new perspective for practical industrial water splitting.