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  • Perspective
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Critical insights into the steam electrolysis electrode in protonic ceramic cells for hydrogen production

Nature Catalysis volume 8, pages 293–300 (2025)Cite this article

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Abstract

Intermediate-temperature protonic ceramic electrolysis cells (PCECs), which combine the benefits of both lower- and higher-temperature electrolysis, are among the most efficient technologies for the production of green hydrogen. To ensure economic competitiveness and broad adoption, ongoing innovations in cell materials are essential to improve durability and reduce costs. The water oxidation half-reaction at the anode is a key area for improvement as it is a major contributor to performance degradation and efficiency loss in PCECs. Current anode designs, which are largely derived from solid oxide electrolysis cells, fail to address the specific requirements for PCECs under realistic operating conditions. This Perspective highlights the unique challenges faced by PCEC anodes, focusing on the impact of high steam concentrations and the critical role of proton-coupled electron-transfer mechanisms—factors that are absent in solid oxide electrolysis cells. Furthermore, we explore design principles for advancing anodes tailored for PCECs, offering guidance for future research and development in this promising field.

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Fig. 1: IT PCECs for green hydrogen production.
Fig. 2: Illustrative comparison of oxygen electrode operating conditions in SOECs and PCECs.
Fig. 3: PCET mechanisms in water oxidation.
Fig. 4: Development of advanced oxygen electrode materials in PCECs.

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Acknowledgements

This work is supported by the proton-conducting solid oxide electrolysis cells (P-SOEC) lab call project and the HydroGEN Advanced Water Splitting Materials Consortium, established as part of the Energy Materials Network under the US Department of Energy (USDOE); the Office of Energy Efficiency and Renewable Energy (EERE); the Hydrogen and Fuel Cell Technologies Office (HFTO) under the USDOE Idaho Operations Office under contract no. DE-AC07-05ID14517. M.L. is grateful for the support from the Idaho National Laboratory’s Laboratory Directed Research and Development program (project no. 23A1070-027FP) under the USDOE Idaho Operations Office under contract no. DE-AC07-05ID14517.

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  1. These authors contributed equally: Meng Li, Fan Liu.

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  1. Energy and Environmental Science and Technology, Idaho National Laboratory, Idaho Falls, ID, USA

    Meng Li, Fan Liu & Dong Ding

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  1. Meng Li
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Contributions

D.D. conceived the idea of this Perspective. M.L. and F.L. wrote the first draught of the paper. All authors contributed to reviewing and editing the manuscript.

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Correspondence to Meng Li or Dong Ding.

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Nature Catalysis thanks Wei Wang and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Li, M., Liu, F. & Ding, D. Critical insights into the steam electrolysis electrode in protonic ceramic cells for hydrogen production. Nat Catal 8, 293–300 (2025). https://doi.org/10.1038/s41929-025-01313-w

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