IrRuOx/TiO2 a stable electrocatalyst for the oxygen evolution reaction in acidic media

Proton Exchange Membrane Electrolysis of Water (PEMWE) stands out as a scalable, CO2-free process to produce H2 for energy delivery and industrial applications. Due to the limited Ir and Ru worldwide availability, one of the main challenges for the GW-scale PEMWE implementation is the loading reduction of these metals in the anodic catalytic layer. Here, Ir–Ru loading (5 wt%Ir-40 wt%Ru) was deposited through their impregnation over TiO2, followed by a thermal-oxidative treatment, obtaining IrRuOx/TiO2 catalyst. SEM-EDS and HR-TEM confirmed the homogeneous dispersion of IrRuOx on TiO2. The supported catalyst showed a 1.4-fold higher mass activity (85 mA/mg Ir–Ru) for the oxygen evolution reaction (OER) than a mechanical mixture of IrO2–RuO2 1:3 (54 mA/mgIr+Ru) in H2SO4 0.5 M, at 1.52 V/RHE. Furthermore, the supported catalyst retains 90% of its catalytic activity after 100 reaction cycles suggesting the RuO2 intermediate species stabilization by IrOx, which can avoid its irreversibly transform into hydrous RuOx.