Regulating Ru-O Bonding Interactions by Ir Doping Boosts the Acid Oxygen Evolution Performance

Highly active and stable oxygen evolution reaction (OER) catalysts are crucial for the large-scale application of proton exchange membrane water electrolyzers. However, the dynamic reconfiguration of the catalyst surface structure and active centers is still undefined, which greatly hinders the development and application of efficient OER catalysts. Herein, we report an Ir0.3Ru0.7Ox/C catalyst with a facile low-temperature synthesis route, which can reach 10 mA cm-2 at an overpotential of 217 mV with a Tafel slope as low as 39.4 mV dec-1, and yields a mass activity 61 times that of commercial IrO2/C at an overpotential of 300 mV. The lattice oxygen structure of RuOx is stabilized by the introduction of Ir species, thus greatly promoting the OER activity and durability. Further in situ Raman reveals that RuOx emerges as the active species at high potentials, and Ru-O bonding interactions are enhanced with Ir regulation, stabilizing the solvation of Ru at high potentials and accelerating the nucleophilic attack of water molecules, leading to the improved OER performance. This work deepens the fundamental understanding of OER and offers an effective way to advance the utilization of Ru-based OER catalysts. Ru-O bonding interactions are enhanced via Ir regulation, stabilizing the solvation of RuOx at high potentials, thus greatly improving the activity and stability towards OER.+ image