Researchers have used a “data factory” to discover a replacement for the expensive precious metal iridium. This breakthrough could make the production of green hydrogen significantly cheaper and accelerate the energy transition.

Green hydrogen as the key to the energy transition

Green hydrogen is considered a key energy source, particularly for industries such as cement and steel manufacturing that are difficult to decarbonize. It can be produced using the PEM electrolysis process: water is split into hydrogen and oxygen using renewable energy.

Until now, iridium has been required as an anode catalyst for this process. The metal accelerates the oxygen evolution reaction (OER), but is extremely expensive and rare. A gram of iridium costs around 125 euros – more than gold. Global supplies are insufficient to meet forecast demand.

The megalibrary contains millions of unique nanoparticles on a chip. Each particle is made up of combinations of metals such as ruthenium, cobalt, manganese and chromium. A robot scanner automatically checked which particles carry out the oxygen evolution reaction most efficiently.

New catalyst outperforms iridium in the laboratory

After testing, the research team selected the best-performing combinations. The composition particularly stood out Ru52Co33Mn9Cr6 oxide – a precise mixture of the four metals. The new catalyst even showed slightly higher activity and exceptional stability compared to iridium on a laboratory scale.

“The other elements stabilize ruthenium, which is typically less stable,” explains Chad A. Mirkin, lead author of the study.

“An army of researchers on one chip”

With the mega library, countless material combinations can be simulated and tested extremely quickly. Mirkin compares each nanoparticle dot to a tiny researcher in a microlab: “Instead of individual researchers, we have millions of researchers on a chip.”

Together with the Toyota Research Institute (TRI), the scientists then tested the catalyst in larger quantities. The material proved to perform well in real hydrogen production scenarios.

Long-term test and cost advantage

The new catalyst passed long-term tests of over 1000 hours with high efficiency in an acidic environment. Additionally, it only costs about one-sixteenth of the price of iridium. “We can now not only quickly identify catalysts, but also test their suitability in scaled applications,” explains Joseph Montoya from TRI.

Although further work is necessary, In order to use the material commercially, the method opens up a quick, cost-effective alternative to iridium and an important step towards efficient energy innovation.