Breaking Down the Performance Losses in O₂-Evolution Stability Tests of IrO₂-based Electrocatalysts

Understanding the deactivation mechanisms affecting state-of-the-art, Ir oxide catalysts employed in polymer electrolyte water electrolyser (PEWE-) anodes is of utmost importance to guide catalyst design and improve PEWE-durability. With this motivation, we have tried decouple contributions various degradation overall performance losses observed rotating disk electrode (RDE) tests on three different, commercial (pure or supported Nb 2 O 5 ). Specifically, investigated whether these decays stem from an intrinsic caused by alterations their oxidation state, crystalline structure, morphology and/or Ir-dissolution, also assessed possible decreases loading delamination materials over course OER-stability tests. Additionally, examined recently reported artifacts related use RDE voltammetry for such measurements found that neither nor above (or combinations thereof) can cause totality losses. Beyond uncertainties, complementary PEWE-tests showed apparent RDE-instability not reproduced application-relevant environment.