TNO develops electrolyzer with 200 times less iridium

TNO researchers were the first to create a process that uses 200 times less iridium while still producing electrolyzers that perform between 25% and 46% better than the present generation. For this technique, a patent application has been filed.

“The expected growth of green hydrogen from 300 megawatts in 2020 to tens of gigawatts in 2030 has a flipside”, explains TNO expert, Lennart van der Burg. “It implies a proportionately growing demand for the scarce iridium for the electrolysers that will need to be built. Earlier TNO research revealed that the scaling up of electrolysis could be hampered by the extremely limited availability of scarce resources, especially iridium and platinum. In ten years’ time, the demand for iridium will vastly exceed its availability. Moreover, we rely on a small group of countries for its delivery, with all the risks that implies.”

Electrolysis experts from the Faraday Lab in Petten, part of TNO, worked with associates from the Holst Center in Eindhoven. The spatial Atomic Layer Deposition (sALD) technology, a technique for depositing incredibly thin layers of useful materials on sizable surface regions, was created by TNO before. The next generation of television, tablet, and smartphone screens was supposed to be created with this technology. Recently, the study team expanded the technology’s applicability to electrolysers.

TNO has been working with the sALD technology for the past two years. Instead of using a membrane, as is usual today, researchers put an ultrathin layer of iridium as a catalyst material over a porous titanium transport layer. After many lab testing, the new method’s functionality and stability were established. After the first round of stress testing, there was little to no degradation. Additionally, the membrane of the electrolyser is free of iridium, which facilitates recycling and reuse.

Scaling up

TNO is aiming to bring this promising technology from the lab to reality as part of the Voltachem program along with a number of other top industrial partners. In order to show that the procedure works in practical settings, it must be scaled up to pilot scale.