Influence Of The Mno2 Phase On Oxygen Evolution Reaction Performance For Low-Loading Iridium Electrocatalysts

Developing high-performance, low-loading, Ir-based electrocatalysts for the oxygen evolution reaction (OER) in acidic media is still a great challenge. Herein, we fabricated an iridium manganese catalyst with only 5 % iridium. The influence of the manganese dioxide phase states (alpha-, beta-, gamma- and delta-MnO2) on the OER performance of IrO2/MnO2 catalysts was investigated. alpha-MnO2, as the substrate, can generate smaller iridium particles and more high-valence-state iridium to promote OER performance. Therefore, the 5 % IrO2/alpha-MnO2 electrocatalyst exhibits excellent electrocatalytic OER performance with a high mass activity of 216.67 A/g(Ir) and 655.33 A/g(Ir) at 1.53 V in acidic and alkaline media, respectively, significantly outperforming commercial IrO2.