A team of researchers in South Korea has developed a new catalyst that can repair itself after damage, potentially solving one of the biggest problems facing hydrogen energy technologies.
The breakthrough could help improve the durability of hydrogen fuel cells and water electrolyzers, two technologies that are expected to play an important role in the transition to cleaner energy.
The research was led by scientists from Pohang University of Science and Technology (POSTECH), Kongju National University, Seoul National University, and the Pohang Accelerator Laboratory.
Their findings were published in the journal Energy & Environmental Science.
Catalysts are materials that speed up chemical reactions without being consumed themselves. In hydrogen energy systems, catalysts are essential because they help split water into hydrogen and oxygen or generate electricity from hydrogen fuel.
However, catalysts face a major challenge during operation. Over time, their surfaces can become covered by oxide layers.
This process, known as oxidative passivation, blocks the active sites where chemical reactions occur. Once this happens, the catalyst loses efficiency, and the damage is often permanent.
The problem is particularly severe during sudden changes in operating conditions, such as when a fuel cell starts up, shuts down, or temporarily runs out of fuel. These events can dramatically shorten the lifespan of hydrogen energy systems.
To address this issue, the research team designed a new catalyst made from an iridium-iron alloy known as IrFe/C.
What makes this catalyst special is its unique structure. The outer surface and inner core of each tiny catalyst particle perform different functions. The surface is designed to react to changing conditions, while the inner metallic core remains stable and protected.
When oxidation occurs, only the outermost layer of the catalyst is affected. Instead of suffering permanent damage, the surface can rebuild itself and restore its active metallic state once operating conditions improve.
The researchers describe this process as “dynamic segregated-surface reconstruction.” In simple terms, the catalyst’s surface continuously adapts and regenerates while the core maintains the overall structure.
This self-healing ability allows the catalyst to recover from damage that would permanently degrade conventional materials.
To test the technology, the team used the catalyst in practical hydrogen energy devices, including polymer electrolyte membrane water electrolyzers and fuel cells.
The results were impressive. Conventional platinum-based catalysts experienced a performance loss of about 62% after repeated shutdown tests. In comparison, the new iridium-iron catalyst showed only a 16% decline in performance under the same conditions.
The catalyst also remained highly stable during fuel starvation and other stressful operating situations that typically damage fuel-cell components.
Researchers say this represents a new approach to improving catalyst durability. Instead of trying to prevent oxidation entirely, the new design allows the catalyst to recover naturally after oxidation occurs.
Because the technology works in both water electrolyzers and fuel cells, it could have broad applications across the hydrogen energy industry.
As hydrogen becomes increasingly important in efforts to reduce carbon emissions, longer-lasting catalysts could help lower costs, improve reliability, and accelerate the adoption of clean energy systems.
This self-healing catalyst may be an important step toward making hydrogen technologies more practical for widespread use.
