Influence of Temperature on the Performance of Carbon- and ATO-supported Oxygen Evolution Reaction Catalysts in a Gas Diffusion Electrode Setup

State-of-the-art industrial electrocatalysts for theoxygen evolutionreaction (OER) under acidic conditions are Ir-based. Considering thescarce supply of Ir, it is imperative to use the precious metal asefficiently as possible. In this work, we immobilized ultrasmall Irand Ir0.4Ru0.6 nanoparticles on two differentsupports to maximize their dispersion. One high-surface-area carbonsupport serves as a reference but has limited technological relevancedue to its lack of stability. The other support, antimony-doped tinoxide (ATO), has been proposed in the literature as a possible bettersupport for OER catalysts. Temperature-dependent measurements performedin a recently developed gas diffusion electrode (GDE) setup revealthat surprisingly the catalysts immobilized on commercial ATO performedworse than their carbon-immobilized counterparts. The measurementssuggest that the ATO support deteriorates particularly fast at elevatedtemperatures.