UK- and US-based Phasecraft has secured $4.5m from the US Department of Energy (DOE) to develop quantum algorithms aimed at discovering new catalysts for hydrogen production that reduce reliance on iridium, one of the world’s rarest metals.
The funding comes from the DOE’s Advanced Research Projects Agency-Energy, which launched a programme to advance solutions to chemistry and materials science problems using quantum computing.
For this project, Phasecraft will develop quantum algorithms to simulate and discover new catalysts that could produce low-cost hydrogen and reduce the reliance on critical minerals like iridium, which is used in catalysis.
“Cutting the iridium requirement in industrial electrolysis would meaningfully change the economics of hydrogen fuel and a wider class of catalytic processes that underpin energy security,” said Steve Flammia, Principal Quantum Scientist and head of Phasecraft US.
Iridium catalysts are considered the gold standard for proton exchange membrane (PEM) water electrolysers used to produce green hydrogen.
Unlike other metals, iridium can withstand the highly corrosive acidic environments needed to drive the oxygen evolution reaction – the key process used when splitting water to produce green hydrogen.
However, the material is one of the rarest naturally occurring elements in the Earth’s crust, with an abundance of only 0.001 parts per million. It is so rare that just three tonnes are produced each year globally.
Iridium is roughly 40 times rarer than gold in the Earth’s crust. Because of its extreme scarcity, global production is limited to just a few tonnes per year ©Shutterstock
This has created a supply bottleneck for PEM electrolysis, which requires around 300 to 400kg of iridium per gigawatt of capacity.
The material is also in high demand from competing sectors such as electronics, military, and transportation, causing prices to hit upwards of $6,000 per ounce.
Because classical computers struggle to simulate the complex quantum behaviour of atoms, quantum computing could advance the hydrogen economy by modelling chemical reactions to design new, more efficient catalysts.
“Delivering significant quantum speed ups with hardware-adaptive algorithms could help shape iridium requirements in a matter of years, not decades,” added Flammia.
Finding a better alternative could help offset some of iridium’s operational trade-offs. While splitting water into oxygen within a PEM electrolyser, unstable iridium atoms with ‘high surface energy’ can dissolve and wash away, causing the catalyst to fail prematurely.
And according to research, lab-testing often overestimates the lifespan of tiny iridium nanoparticles compared to a real-world environment, where high heat and fluctuating pressures rapidly break chemical bonds and poison the catalyst. These harsh, operational conditions accelerate the breakdown of the material compared to controlled, laboratory scenarios.
Data gathered from the project will also provide insights into syngas production, petroleum refining, metallurgy, and other industrial sectors whose economics depend on the chemistry of catalysts.
According to the company, its algorithms have already achieved efficiency improvements of up to 43,000,000 times over previous quantum methods.
The project will advance with partners Johnson Matthey, Harvard University, and QuEra.
Other methods to reduce iridium use are under development elsewhere. Dutch company TNO Holst has developed a technology called spatial atomic layer deposition, which enables the application of atom-thin layers of iridium to electrolysers so much less is needed.
“We’ve succeeded in developing a method that requires 200 times less iridium and which already achieved 25 to 46% of the performance of the current generation of electrolysers,” said Lennart van der Burg, Cluster Manager Green Hydrogen at TNO.
Meanwhile, Rice University has developed a new catalyst that reduces pure iridium use by 80% by integrating it with ruthenium – a material roughly 100 times more common than iridium.
Iridium bottleneck is no longer an issue?
Speaking during a gasworld webinar earlier this year, Manuel Kuehn, VP of Global Sales, Sustainable Energy Systems at Siemens Energy, sees the iridium bottleneck challenge as a non-issue.
“We don’t think it’s an issue anymore,” he said. “We thought it was but [we have] changed our opinion over recent years and there are a couple of reasons.”
One reason is that the market is not growing as fast as initially believed, which means the total of iridium that needs to be sourced is less than expected.
“Second, we [and others] are running programmes to reduce the iridium loading in [our] stacks [of electrolysers]. That means the amount of iridium I need per square centimetre is going down over time.”
According to Kuehn, the company is able to do this without compromising on performance.
“Third, we figured out how to recycle the stacks and how to recuperate the iridium once we get a stack back, so we know that we have a pretty decent recovery quota of the precious metals that are in the existing acids,” he explained.
After the first generation of stacks come out of operation, the company will be able to recycle them back into the system.
“All these measures combined lead to the fact that we currently don’t see iridium supply as a significant bottleneck in the PEM industry.”
