An international research team has developed a simple, air-based method to create iridium nanoclusters just 15 atoms wide, a feat long considered extremely challenging. The clusters sustain stable operation for more than 20 hours without performance loss.
The work involved researchers from Tohoku University, Tokyo University of Science, Vanderbilt University and the University of Adelaide. Their ambient-air synthesis sidesteps the complex, inert-atmosphere techniques typically required for such precision nanostructures.
In side-by-side tests, the 15-atom clusters achieved 1.5 times higher mass activity than commercially available iridium catalysts. The team also confirmed that the clusters maintained their structure and activity over extended use.
The discovery could lower the cost and improve durability of catalysts used in clean energy technologies, such as hydrogen production and fuel cells. Iridium is rare and expensive, so boosting its efficiency per atom is a significant advance.
The researchers note that scaling the synthesis from lab to industry remains unproven, and the long-term stability under real-world operating conditions has yet to be tested.