Ce-Doped IrO₂ Electrocatalysts with Enhanced Performance for Water Oxidation in Acidic Media

Abstract

Electrocatalytic water splitting in acidic media based on a proton-exchange membrane (PEM) is a promising technique for the large-scale production of hydrogen. However, developing electrocatalysts with high activity and excellent stability for an oxygen evolution reaction (OER) in acidic media is still a big challenge. Herein, a Ce<i>_x</i>-IrO₂ catalyst supported on N-doped porous carbon (NPC) was developed via doping Ce into IrO₂ nanoparticles. The Ce<i>_x</i>-IrO₂ nanoparticles were uniformly distributed on NPC due to the high surface area. The optimized Ce_0.2-IrO₂@NPC delivers a low overpotential of 224 mV and excellent stability of 100 h in 0.5 M H₂SO₄ at 10 mA cm^-2. Density functional theory (DFT) calculations indicated that the introduction of Ce could modify the electronic structure of IrO₂, decreasing the energy barrier of the rate-determining step for OER and enhancing the electrochemical OER performance. Our work opens up a new way of developing anodic electrocatalysts, which can be stably applied in acidic media.