From activity to durability: Structural evolution of amorphous and crystalline iridium oxides in PEM water electrolyzers

Kwon O, Oh J, Hannadige LP, Yang P, da Silva GC, Morimoto Y, Cherevko S, Korzeniewski C, Zachman MJ, Zenyuk IV (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Applied Catalysis B-Environmental Elsevier

Book Volume: 399

Article Number: 127150

DOI: 10.1016/j.apcatb.2026.127150

Abstract

Iridium oxide catalyst dissolution is a major degradation concern for proton exchange membrane water electrolyzers (PEMWEs). Selecting catalysts meeting both activity and durability targets remains challenging due to the inverse relationship between these metrics. This work investigates the structural and chemical evolution of membrane electrode assemblies (MEAs) featuring amorphous IrOx and crystalline IrO2 undergoing 750 h of harsh oxidative stress tests. Extensive characterization was performed to understand the structural evolution of iridium oxides. Amorphous IrOx exhibited rapid degradation also in performance, observing a phase transition from amorphous to crystalline-like structure after 750 h of testing. Crystalline IrO2 demonstrated exceptional durability of voltage decay of 2 μV h −1 at 3 A cm−2. Furthermore, crystalline IrO2 showed no evidence of changes in its electronic or material structure. The insights this work provides crucial insights for designing durable MEAs necessary for next-generation PEMWEs.

Involved external institutions

University of California Los Angeles (UCLA) US United States (USA) (US) Texas Tech University (TTU) US United States (USA) (US) Forschungszentrum Jülich / Research Centre Jülich (FZJ) DE Germany (DE) Oak Ridge National Laboratory US United States (USA) (US)

How to cite

APA:

Kwon, O., Oh, J., Hannadige, L.P., Yang, P., da Silva, G.C., Morimoto, Y.,... Zenyuk, I.V. (2026). From activity to durability: Structural evolution of amorphous and crystalline iridium oxides in PEM water electrolyzers. Applied Catalysis B-Environmental, 399. https://doi.org/10.1016/j.apcatb.2026.127150

MLA:

Kwon, Obeen, et al. "From activity to durability: Structural evolution of amorphous and crystalline iridium oxides in PEM water electrolyzers." Applied Catalysis B-Environmental 399 (2026).

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