Smoltek Hydrogen and Heraeus Precious Metals are advancing a new generation of PEM electrolysis technology designed to dramatically reduce the amount of iridium required for green hydrogen production. The partners are preparing a 3,000-hour durability test as they move the technology closer to commercial and industrial deployment.
The collaboration focuses on developing ultra-low-iridium Porous Transport Electrodes (PTEs) for proton exchange membrane (PEM) water electrolysers. Long-term testing of Smoltek’s nanostructured iridium catalyst layer is scheduled to begin in autumn 2026.
The test programme represents an important step in determining whether the technology can maintain its performance and stability over extended periods under realistic operating conditions.
Tackling an important constraint for PEM electrolysis
Iridium is a critical material in PEM electrolysers, but its high cost and limited availability represent a challenge for scaling the technology as demand for renewable hydrogen grows.
Smoltek and Heraeus are seeking to address this issue by substantially reducing iridium loading without compromising electrolyser efficiency or durability.
Smoltek says its nanostructured catalyst architecture can bring iridium loading to below 0.1 mg/cm². The catalyst layer is only a few microns thick and has been engineered to improve charge and mass transport.
“Our nanostructured layer offers a unique capability to maximize charge and mass transport properties within a thickness of just a few microns,” said Fabian Wenger, Head of R&D at Smoltek Hydrogen. “By optimizing this specific catalyst architecture, we can simultaneously maintain high electrolyzer efficiency while successfully reducing the amount of iridium needed to below 0.1 mg/cm² loading.”
If the technology proves durable at such low iridium levels, it could help reduce material requirements for future PEM electrolyser manufacturing and potentially improve the economics of scaling green hydrogen production.
3,000-hour test moves technology toward industrialisation
The partnership combines Smoltek’s nanotechnology with Heraeus Precious Metals’ expertise in precious-metal electrocatalysts, testing and material analysis.
Heraeus will lead the upcoming 3,000-hour testing campaign, assessing the long-term operational stability of the catalyst technology and conducting the material analysis needed for further validation.
“We are looking forward to commencing this extensive testing campaign and to provide the critical material analysis required to validate this technology,” said Christian Gebauer, Head of Innovation at the Hydrogen Systems Division of Heraeus Precious Metals.
The durability programme is particularly important because reducing catalyst loading alone is not sufficient for commercial deployment. The electrodes must also demonstrate that they can maintain performance over prolonged operation.
For Smoltek and Heraeus, successful completion of the testing programme would therefore represent another step toward industrialising ultra-low-iridium PEM electrolysis, with the broader objective of making green hydrogen production less dependent on scarce precious metals and more economical to scale.