Active and Stable Layered Alkali Iridates Efficiently Catalyze Oxygen Electroevolution in Low-Ir Proton-Exchange Membrane (PEM) Water Electrolyzers

Kang J, Möhle S, Wang X, Kovács MM, Drnec J, Nasralla KN, Buchheister PW, Schmidt J, Dworschak D, Strasser P (2025)

Publication Type: Journal article

Publication year: 2025

Journal

Journal of the American Chemical Society American Chemical Society

Book Volume: 147

Pages Range: 45230-45239

Journal Issue: 49

DOI: 10.1021/jacs.5c14847

Abstract

Developing catalysts with improved activity and stability compared to rutile IrO2 or amorphous IrOx remains a technical priority for advancing the oxygen evolution reaction (OER) in proton-exchange membrane water electrolyzers (PEMWEs). Here, we report structure-OER activity-stability relationships across a family of alkali cation-intercalated iridates, uncovering a structural evolution from hollandite to layered-type structures, characterized by the ratio of edge-sharing to corner-sharing connections of [IrO6] octahedral motifs. In particular, Li-IrOx and Cs-IrOx demonstrate excellent PEMWE performance over a wide current range, pushing Ir demand to new lows. Both achieve a power-specific Ir demand of 0.06 gIr kW-1. However, Cs-IrOx shows a greater potential for long-term stability, indicating that iridates with a higher proportion of edge-sharing motif connections possess enhanced structural robustness. This work offers new insights into balancing catalytic activity and stability through atomic-scale motif connectivity tuning and presents a viable alternative to state-of-the-art rutile or amorphous iridium oxides.

Involved external institutions

Technische Universität Berlin DE Germany (DE) Forschungszentrum Jülich / Research Centre Jülich (FZJ) DE Germany (DE) European Synchrotron Radiation Facility (ESRF) FR France (FR)

How to cite

APA:

Kang, J., Möhle, S., Wang, X., Kovács, M.M., Drnec, J., Nasralla, K.N.,... Strasser, P. (2025). Active and Stable Layered Alkali Iridates Efficiently Catalyze Oxygen Electroevolution in Low-Ir Proton-Exchange Membrane (PEM) Water Electrolyzers. Journal of the American Chemical Society, 147(49), 45230-45239. https://doi.org/10.1021/jacs.5c14847

MLA:

Kang, Jiaqi, et al. "Active and Stable Layered Alkali Iridates Efficiently Catalyze Oxygen Electroevolution in Low-Ir Proton-Exchange Membrane (PEM) Water Electrolyzers." Journal of the American Chemical Society 147.49 (2025): 45230-45239.

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