Slot-die technology meets scalable green hydrogen production

Fig. 1 Design strategies and future challenges in developing Ir-based catalysts for practical PEMWE [1].

Advanced catalyst engineering provides the necessary tools to redesign catalyst surfaces.

Altering the surface chemistry enables higher performance, longer lifetimes, and more efficient use of scarce materials like iridium. Molecular-level enhancements, such as surface-grafted sulfonic groups, fundamentally improve how catalysts manage proton transport, water activation, and surface stability.

Fig. 2 Mechanism of SO42− in proton transfer [2].

Traditionally, researchers have mixed sulfonate additives into catalyst layers to help proton transport [3][4]. Those additives tend to leach out over time during operation [5], reducing efficiency and shortening the lifetime of the electrolyzer.

One way to address this challenge is to create a stable hybrid material through a one-step grafting reaction that preserves the original oxide structure [2]. The linkage formed is a robust covalent bond, not an ionic interaction or a weakly adsorbed species that can wash away under acidic, high-current OER conditions [2]. Structurally, the modification does not alter the catalyst’s oxide identity. After 1000 hours of operation in an electrolyzer, the chemical signature remains unchanged, and the sulfur content stays the same [2].

This small surface-level change has big consequences. As the sulfonic acid group is highly acidic and strongly hydrophilic, it attracts water and conducts protons exceptionally well. Its strong polarity and ability to form stable chemical bonds make it valuable for enhancing both catalyst performance and improving ink stability.

Fig. 3 SEM images of Ir/IrOx catalyst layers cross-section and picture of the slot-die equipment working on large-scale electrode deposition (54 cm x 45 cm) [2].

The combination of surface-engineered catalysts and scalable thin-film manufacturing is what will ultimately enable Power-to-X technologies to grow from pilot projects to gigawatt-scale commercial systems.

At FOM Technologies, we closely follow and actively support these developments by working with research institutes and industrial partners to advance scalable production of thin-film components essential to next-generation electrolyzers.

Our pilot-line machinery enables industry to evaluate and scale up advanced electrode and membrane coating methods, accelerating the transition to commercially viable green hydrogen production.

Sheet coaters are the fastest path from concept to validated electrolyzer components in Power-to-X. They enable precise, uniform layers from small ink volumes, quick recipe changes, and reproducible outcomes, supported by solvent-resistant stainless-steel wetted parts and temperature-controlled substrate handling. In practice, teams use FOM vectorSC for intermediate method development and FOM alphaSC for advanced studies when tighter motion control, wider formats, and richer data capture are required. Together, these sheet systems de-risk electrode and membrane coating, providing a clean handover to pilot-scale roll-to-roll.

References

[1] Wang, C., & Feng, L. (2024). Recent advances and perspectives of Ir-based anode catalysts in PEM water electrolysis. Energy Advances, 3, 14–29. https://doi.org/10.1039/D3YA00492A

[2] Li, J., Fu, S., Wang, R. et al. Surface sulfonic-group bonded oxygen evolution catalyst for proton exchange membrane water electrolysis. Nat Commun 16, 9910 (2025). https://doi.org/10.1038/s41467-025-64857-2

[3] Zhang, T. et al. Oxidation state engineering in octahedral Ni by anchored sulfate to boost intrinsic oxygen evolution activity. ACS Nano 17, 6770–6780 (2023).

[4] Zhang, R. et al. Solid-acid-mediated electronic structure regulation of electrocatalysts and scaling relation breaking of oxygen evolution reaction. Appl. Catal. B 277, 119237 (2020).

[5] Chen, Q., Zhang, Q., Chen, B., Zhang, J., Peng, W., Li, Y., & Fan, X. (2024). Enhanced Long‐Term Performance of Sulfides in Oxygen Evolution Reaction by Sulfate Ion‐Assisted Strategy. Advanced Functional Materials, 34(44), 2406233.

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