Scientists have achieved a major milestone in addressing one of the most significant hurdles impeding the widespread adoption of green hydrogen: the limited availability of iridium, a rare and costly metal central to current hydrogen production technology.
“Right now, the most advanced technology for sustainable hydrogen production uses iridium-based catalysts in proton-exchange membrane water electrolysers,” explained lead study author Associate Professor Alexandr N. Simonov from the Monash University School of Chemistry.
“But there simply isn’t enough iridium mined to build the scale of electrolysers needed for green hydrogen to truly decarbonise our energy and chemical industries.”
As the world intensifies its pursuit of green hydrogen as a clean energy carrier, industry experts have faced a sobering reality: while iridium-based catalysts are highly effective, their scarcity poses a substantial bottleneck to the global deployment of the technology at the multi-gigawatt scale required for meaningful impact.
In response, researchers worldwide have turned their focus to finding high-performance anode catalysts made from more readily available and affordable materials.
One promising candidate has been cobalt, which has sparked optimism following recent advances by the Monash team.
However, the widespread use of cobalt catalysts has long been hampered by concerns over stability in harsh electrolytic environments.
“Cobalt is much cheaper than iridium, but the challenge has always been making cobalt-based catalysts stable enough to survive the harsh conditions inside these electrolysers,” noted study contributor Monash PhD alumnus Dr Darcy Simondson.
A new paper published today in Nature Energy, led by the Monash University School of Chemistry in collaboration with the Max Planck Institute for Chemical Energy Conversion, Swinburne University of Technology, Los Alamos National Laboratory, Helmholtz-Zentrum Berlin for Materials and Energy, Cambridge University, and major synchrotron facilities, unravels the intricate details of why cobalt catalysts degrade — and, crucially, how to overcome this limitation.
“This was more than three years of research using some of the world’s most advanced spectroscopic, electrochemical, and computational techniques,” said Dr Marc Tesch from the Max Planck Institute for Chemical Energy Conversion.
“We discovered that the major catalytic function of these cobalt-based anodes, and their degradation, actually occur independently of each other.
“That wasn’t what was expected from the previous research.”
This pivotal insight overturns previous assumptions and could transform catalyst design.
By showing that performance and degradation are decoupled, scientists now have a blueprint for engineering cobalt materials to maximise efficiency while independently addressing longevity.
“Essentially, we’ve uncovered that these processes run in parallel rather than being directly linked.
“That gives us a clear pathway to making cobalt-based anodes robust and economically viable for green hydrogen production.
“There is also a potential to apply the same synchrotron methods to other catalysts, providing critical insights across a range of systems,” said study contributor Associate Professor Rosalie Hocking from Swinburne University of Technology.
These findings bring the prospect of affordable, large-scale green hydrogen closer to reality.
If cobalt-based catalysts can be engineered for long-term stability, the technology could unlock vast new capacity for renewable fuel production worldwide.
“This research is critical for the development of new anodes that don’t rely on scarce materials,” stated Associate Professor Simonov.
“Green hydrogen can be a major tool in decarbonising our economy but only if we can make its production truly sustainable and scalable.”
The project received support from Monash University, the Australian Research Council, the Office of Naval Research Global, the Australian Renewable Energy Agency, Deutscher Akademischer Austauschdienst (DAAD), the German Federal Ministry of Education and Research (BMBF), and numerous international partners.
