Enhancing Oxygen Evolution Reaction of Co-Based Catalysts via Simultaneous Electrochemical Phosphorus Doping

Abstract

Developing robust catalysts for the oxygen evolution reaction (OER) is critical to advancing anion exchange membrane water electrolysis (AEMWE). This study introduces a novel strategy to improve the efficiency of Co-based catalysts by incorporating phosphorus doping (P-doping) through the simultaneous co-electrodeposition of Co and P. This P-doping approach not only significantly increases the number of active Co sites but also optimizes the oxidation state of Co, contributing to enhanced catalytic activity. The optimized catalyst demonstrates an overpotential of approximately 211 mV at 10 mA cm^–2 with a Tafel slope of 36.5 mV dec^–1 under half-cell conditions in 1 M KOH. In an AEMWE single-cell system, the catalysts shows a current density of 2100 mA cm^–2 at 1.8 V and 60 °C, with a degradation rate of 0.19 mV h^–1 over 1000 h at 1 A cm^–2. These results suggest that simultaneous P-doping is an effective strategy to enhance OER activity.