Interview with "The Hydrogen Standard" on How Heraeus Precious Metals Applications Facilitate the Development of the Hydrogen Economy

Dr. Christian Gebauer, head of Hydrogen Systems at Heraeus, tells The Hydrogen Standard that there are three primary areas in which the company’s efforts are now directed.

Heraeus Precious Metals is the global business unit of the Heraeus group that is mainly specialised on precious metals. Firstly, with precious metals trading, there is the provision of precious metals to the industry and markets. Then, there are all kind of precious metal-based products in a huge variety of industries and applications. And finally, there is a commitment to precious metals recycling in order to achieve sustainability and manage the scarce raw materials in the cycle.

Dr. Gebauer’s personal responsibility is research, and his focus is largely on proton-exchange membrane (PEM) electrolysers and fuel cells, applications that play an important role in the hydrogen ecosystem. Thanks to a large testing site, where Christian’s team can study the behaviour and applications of precious metals, they’re hoping to make breakthroughs with serious implications for the hydrogen industry.

"For example, in order to generate hydrogen out of water," he explains, "you need a catalytic conversion. And those catalysts are built with precious metals— something we obviously have a lot of experience in. A such, we believe that we are well positioned to supply these components to the hydrogen economy."

Even if Heraeus isn’t directly involved in the energy transition, the company will play an absolutely crucial role, nonetheless. While governments will provide a wider roadmap for the energy transition—including the move toward hydrogen—businesses like Heraeus need to implement strategies to make the component supply work.

"You can’t trick physics."

That’s why Heraeus is focusing largely on PEM electrolysis, a technology that’s crucial for hydrogen generation. However, even with state-of the art use of precious metals there isn’t sufficient supply of precious metals to enable Europe to meet its goals for electrolyser capacity, as Dr. Gebauer explains.

"PEM electrolysers use iridium catalysts. Europe alone is planning to build 40GW of electrolyser capacity by 2030, and there is simply not enough iridium around to produce so many electrolysers in the way that they’re currently being built. Thus, we need to work on the levels of iridium required. And this is exactly what we do: Heraeus is trying to find ways to reduce the amount of iridium that each application uses. For achieving the target, the reduction of costs and raw materials is crucial."

Dr. Gebauer’s research goes down to the cellular level to improve these efficiencies—as different precious metals affect the way that the electrolysis works.

"One of the main challenges is choosing the active metal in the catalyst. This decision depends on so many different parameters. Iridium, for example, is very active, but it’s quite slow compared to Ruthenium which is even more active—but has stability issues. However, since Electrolysers are likely to run for 20 years or more, stability is really important."

"This is why," Dr. Gebauer continues, "manufacturers usually try to be on the safe side and use Iridium, not Ruthenium. But they want to make sure that the process works, so they use more iridium than is actually needed. Recent data, for example, shows that up to one gram of iridium are typically used per kilowatt. Given the scarcity of iridium, that’s just too much if these electrolysers want to be rolled out globally."

Instead, Christian suggests that using iridium oxide can help stability and efficiency, so that as little as a fifth of typical iridium levels are used. With the latest low-iridium solutions of Christian’s lab the amount of iridium can be further reduced without compromising the activity levels. "Actually", he says, "each electrolyser shouldn’t be using more than 0.2 grams of iridium per kilowatt. Thanks in part to Heraeus, that’s now possible."

"Ultimately, balancing efficiency with other factors remains a challenge. You can’t trick physics, but you can look for ways to get as much out of the material as possible."