Spurred on by the need to develop cheaper materials for clean hydrogen production, researchers have made a major breakthrough in that search. A team led by Chad A. Mirkin from Northwestern University has identified a new catalyst, Ru52Co33Mn9Cr6 oxide, which presents a viable alternative to iridium. This finding has the potential to significantly change the economics of hydrogen fuel production. Today, iridium is the critical component of efficient water-splitting technology, but it is limited and costly.
Iridium is incredibly rare, with prices approaching $5,000 per ounce, making it roughly 7 times more valuable than gold. This scarcity of a commonly occurring precious metal represents a tremendous barrier for the burgeoning clean hydrogen sector. This entire sector relies on iridium to efficiently split water, an essential reaction that uses electricity to separate water molecules into hydrogen and oxygen.
The Challenge of Iridium
A major problem for researchers and industries alike is their dependency on iridium. This dependence further complicates their ability to produce clean hydrogen fuel at any scale. With projections already showing a growing demand for hydrogen energy, the present supply of iridium won’t be enough to satisfy future requirements. For decades now, scientists have been developing alternative materials to make catalytic processes including electrification of the Haber-Bosch process cheaper and more efficient. So far, most of the substitutes have been unable to deliver the performance and stability that iridium brings with it.
Another challenge limiting production is the high cost of iridium, which makes it cost prohibitive in scaling up clean hydrogen technologies. From governments to companies, the world is making historic commitments to combating climate change, achieving net-zero carbon emissions and moving towards cleaner energy. This has increased the pressure to find economically sustainable substitutes.
Discovery of a New Catalyst
That big idea first hit home when Mirkin’s team used the megalibrary platform — a groundbreaking method his group pioneered in 2016. With this platform, researchers can rapidly design and test millions of unique nanoparticles on a single chip. This process shortens the discovery of new materials tremendously.
Out of this vast search, the newly discovered catalyst, Ru52Co33Mn9Cr6 oxide, rose to prominence. It provides many of the same benefits as iridium, but especially when it comes to cost—less than one-sixteenth the value of iridium. In addition, the new catalyst is more active than iridium by a small margin and shows outstanding stability.
During extreme and accelerated conditions, the Ru52Co33Mn9Cr6 oxide performed effectively over 1,000 hours under harsh acidic conditions. Its longevity and reliability are not trivial benefits either, but make a compelling case for commercial adoption in water-splitting applications. This is an exciting step forward in hydrogen fuel technology.
Implications for Clean Hydrogen Production
The implications of this discovery are profound. Moving beyond iridium could make clean hydrogen fuels vastly cheaper to produce too. This trend would make hydrogen fuels more generally available and much more economical to produce. Every nation is working hard to meet ambitious climate targets. In particular, if they can produce hydrogen at a lower cost, it will accelerate the adoption of hydrogen as a clean energy carrier.
The new catalyst not only has potential applications in hydrogen fuel production but could be valuable in other areas of energy generation and storage. Its versatility is already opening up new possibilities with other renewable energy technologies and will surely continue spurring exciting innovations.