Engineered Tantalum–Iridium Oxide Nanoparticles via High-Temperature Calcination for Oxygen Evolution Catalysis

Malinovic M, Geuß M, Paciok P, Choi J, Wang H, Sanyal S, Pfeifer P, Cherevko S, Heggen M, Ledendecker M (2026)

Publication Type: Journal article

Publication year: 2026

Journal

ChemCatChem Wiley-VCH Verlag

Book Volume: 18

Article Number: e01495

Journal Issue: 2

DOI: 10.1002/cctc.202501495

Abstract

Sustainable hydrogen production via low-temperature water electrolysis is key to advancing the hydrogen economy, with polymer electrolyte membrane water electrolysis (PEM-WE) as a central technology. However, sluggish oxygen evolution reaction (OER) kinetics at the anode limit PEM-WE efficiency. Iridium-based catalysts remain the benchmark due to their balance of activity and stability under harsh conditions, though iridium scarcity necessitates designs with reduced Ir content. Here, we report a highly active and stable OER catalyst based on TaOx–IrO2 nanoparticles synthesized via a reverse microemulsion method and calcined at 800°C. Encapsulation in silica nanoreactors enabled precise control over particle size and crystallinity during thermal treatment. The TaOx–IrO2 catalyst achieves a mass activity of 619 ± 93 mA mgIr−1 at 1.55 VRHE, outperforming commercial IrO2 by a factor of 2.5 and bare IrO2 synthesized under identical conditions. While TaOx is electrochemically inactive, it shows exceptional dissolution resistance. The intrinsic stability of TaOx–IrO2, expressed via the S-number, exceeds that of commercial IrO2 and matches bare IrO2 calcined at 600°C. These results highlight TaOx–IrO2 as a promising OER catalyst, combining enhanced activity with notable stability, and support the development of durable, efficient catalysts for PEM-WE.

Involved external institutions

Forschungszentrum Jülich / Research Centre Jülich (FZJ) DE Germany (DE) Technische Universität München (TUM) DE Germany (DE)

How to cite

APA:

Malinovic, M., Geuß, M., Paciok, P., Choi, J., Wang, H., Sanyal, S.,... Ledendecker, M. (2026). Engineered Tantalum–Iridium Oxide Nanoparticles via High-Temperature Calcination for Oxygen Evolution Catalysis. ChemCatChem, 18(2). https://doi.org/10.1002/cctc.202501495

MLA:

Malinovic, Marko, et al. "Engineered Tantalum–Iridium Oxide Nanoparticles via High-Temperature Calcination for Oxygen Evolution Catalysis." ChemCatChem 18.2 (2026).

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