Regulating Ru-based double perovskite against lattice oxygen oxidation by incorporating Ir for efficient and stable acidic oxygen evolution reaction

Oxygen evolution reaction is one of the core half-reactions in proton-exchange membrane (PEM) water electrolysis, but its slow reaction kinetics has been limiting the overall energy conversion efficiency (e.g., water splitting). It is urgent to develop efficient catalysts for OER in acidic media. At present, Ru-based catalysts have high activity, but their poor stability makes them difficult to be used in acidic oxygen evolution reactions. The involvement of lattice oxygen mechanism (LOM) in the reaction is one of the main causes of instability in Ru-based catalysts. Herein, we synthesized SrRu0.5Ir0.5O3 double perovskite by doping Ir into SrRuO3. The double perovskite displays an extraordinary OER performance with a low overpotential of 185 mV at 10 mA cm−2 current density and maintains its catalytic stability for over 50 h in 0.5 M H2SO4. X-ray photoelectron spectroscopy results show that the electronic synergistic effect between Ir and Ru enables the double perovskite materials with high activity. Meanwhile, the double perovskite catalyst inhibits the occurrence of the lattice oxygen mechanism during the OER, which greatly improve the catalytic stability of Ru-based perovskite materials.