State-of-the-art industrial electrocatalysts for the
oxygen evolution
reaction (OER) under acidic conditions are Ir-based. Considering the
scarce supply of Ir, it is imperative to use the precious metal as
efficiently as possible. In this work, we immobilized ultrasmall Ir
and Ir0.4Ru0.6nanoparticles on two different
supports to maximize their dispersion. One high-surface-area carbon
support serves as a reference but has limited technological relevance
due to its lack of stability. The other support, antimony-doped tin
oxide (ATO), has been proposed in the literature as a possible better
support for OER catalysts. Temperature-dependent measurements performed
in a recently developed gas diffusion electrode (GDE) setup reveal
that surprisingly the catalysts immobilized on commercial ATO performed
worse than their carbon-immobilized counterparts. The measurements
suggest that the ATO support deteriorates particularly fast at elevated
temperatures.