Discovery of Efficient Acidic Oxygen Evolution Electrocatalyst: High-Throughput Computational Screening of MgIrRu Oxide

Abstract

Ensuring high catalytic activity and durability remains a significant challenge in the development of electrocatalysts toward oxygen evolution reaction (OER) in proton exchange membrane water electrolyzer (PEMWE). This study introduces a new research paradigm through high-throughput density functional theory (DFT) calculations to screen efficient acidic OER electrocatalysts, guided by the principle of minimizing thermodynamic free energy and optimizing the adsorption energies of OER intermediates. The incorporation of Ir increases the formation energy of oxygen vacancies and suppresses the lattice oxygen mechanism (LOM) of the RuO₂, thereby enhancing its stability. In addition, Mg modulates the electronic structure of Ru and optimizes the adsorption energies of OER intermediates, thus improving the OER activity of the RuO₂. Electrochemical results reveal that Mg_0.23Ir_0.13Ru_0.64O₂ exhibits a low overpotential of 191 mV at 10 mA cm⁻² and superior mass activity of 338.6 A g_noble-metal⁻¹ at 1.46 V. The PEMWE with Mg_0.23Ir_0.13Ru_0.64O₂ as anode catalyst achieves a current density of 1.0 A cm⁻² at a low electrolysis voltage of 1.81 V and steadily operates at 0.5 A cm⁻² for 42 h with a decay of only 909.5 µV h⁻¹. This work offers a new paradigm for the rational design of highly active and robust acidic OER electrocatalysts.