Smoltek Nanotech Holding announced that group company Smoltek Hydrogen completed a successful long-term test of the company’s newly developed material for PEM electrolyzer cells. During 1000 hours of continuous operation, at 2 A/cm², the company has produced hydrogen with only 0.2 mg iridium/cm² without any degradation of the nanostructure in the cell having occurred.

The material, which consists of a corrosion-protected carbon nanostructure, forms one of the layers in an electrolyzer cell and the technology aims to significantly reduce the amount of iridium used as catalysts to produce hydrogen.

We have now proven that our technology with carbon nanofibers, coated with platinum, creates a stable structure in an anode electrode in a PEM electrolyzer. Our competitive analysis shows that we are the only one with a working solution for the anode side electrode, which is both durable and creates a large surface area for the iridium catalysts. This represents an important milestone for the company and for our dialogues with collaboration partners.

—Ellinor Ehrnberg, President of Smoltek Hydrogen

Full-cell performance measurements show that we have performance comparable to conventional solutions, with only one-tenth as much iridium. During the first 10 hours of the test, the voltage rises from 2.1 to 2.5 volts, then increases only marginally. This is not abnormal for a process like this in a lab environment and it is something we will optimize in the next step in collaboration with customers, for example by using different types of iridium and perhaps also ruthenium.

—Fabian Wenger, head of development at Smoltek Hydrogen

Smoltek Hydrogen’s anode electrode with intact nanostructure after 1,000 hours of continuous operation at 2 A/cm² in an extremely corrosive environment.

In a short time, Smoltek Hydrogen has made great progress towards significantly reducing the amount of iridium in the anode side electrode in electrolyzer cells by using nanofibers as the structure for the catalysis in the cell stack.

In the spring of 2023, the company demonstrated that the newly developed material technology with corrosion-protected nanofibers could reduce the amount of iridium by 80% compared to a conventional material (0.5 mg iridium/cm² compared to 2.5 mg iridium/cm²). This in an initial long-term test with an early prototype of the cell material.

Smoltek Hydrogen aims to reduce the amount of iridium in the electrolyzer cell towards 0.1 mg/cm². It is an ambition that aligns with the hydrogen industry’s goal to be able to scale up the production of electrolysers for large-scale production of fossil-free hydrogen. Iridium is a very expensive and critical precious metal with limited supply. Today it costs about SEK 1.7 million/kg (US$156, ) and is forecast to cost about SEK 8 million/kg in 2030.

Smoltek Hydrogen is developing a vertical nanofiber-based material for the anode porous transport layer (PTL) in PEM electrolyzer cells. The material consists of a sintered porous titanium layer with nanofibers, a conformal platinum corrosion protection and iridium catalyst (a thin nanoparticle layer of iridium).

The material is one of the layers in an electrolyzer cell. When manufacturing electrolyzers, a large number of electrolyzer cells are assembled into a cell stack, which is the main element in the electrolyzer as it is where the electrolysis takes place and hydrogen is produced.