Tunnel-structured IrOx unlocks catalytic efficiency in proton exchange membrane water electrolyzers

Mingcheng Zhang; Wei An; Qianqian Liu; Yuzhu Jiang; Xiao Zhao; Hui Chen; Yongcun Zou; Xiao Liang; Xiaoxin Zou

doi:10.1038/s41467-025-62861-0

Nature Communications (Aug 2025)

Tunnel-structured IrOx unlocks catalytic efficiency in proton exchange membrane water electrolyzers

Mingcheng Zhang,
Wei An,
Qianqian Liu,
Yuzhu Jiang,
Xiao Zhao,
Hui Chen,
Yongcun Zou,
Xiao Liang,
Xiaoxin Zou

Affiliations

Mingcheng Zhang: State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University
Wei An: State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University
Qianqian Liu: State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University
Yuzhu Jiang: State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University
Xiao Zhao: Key Laboratory of Automobile Materials of MOE, School of Materials Science and Engineering, Jilin University
Hui Chen: State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University
Yongcun Zou: State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University
Xiao Liang: State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University
Xiaoxin Zou: State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University

DOI: https://doi.org/10.1038/s41467-025-62861-0
Journal volume & issue: Vol. 16, no. 1
pp. 1 – 15

Abstract

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Abstract Proton exchange membrane water electrolyzers face challenges due to high iridium loading and sluggish oxygen evolution reaction kinetics when using conventional rutile-structured iridium oxide nanocatalysts. Here we find that iridium oxide catalysts with a specific tunnel-type crystal structure exhibit highly localized reactivity, where regions at tunnel mouths drive oxygen evolution far more efficiently than tunnel-wall regions. The intrinsic activity of tunnel mouths is 25-fold higher than that of tunnel walls, with shorter nanorods achieving a better balance between active site exposure and electron/mass transport efficiency. When implemented in proton exchange membrane water electrolyzers, this engineered catalyst achieves notable performance at low iridium loading (0.28 mgIr cm−2), delivering over 2.0 A cm−2 at 1.8 V (80 °C) and operating stably for 1800 h—notably outperforming conventional catalysts. Our work identifies catalytic hotspots in tunnel-structured oxides and demonstrates their rational integration into high-performance, durable electrolyzer systems.

Published in Nature Communications

ISSN: 2041-1723 (Online)
Publisher: Nature Portfolio
Country of publisher: United Kingdom
LCC subjects: Science
Website: https://www.nature.com/ncomms/

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