Tohoku University Researchers Develop High-Entropy Perovskite Catalyst for Proton Exchange Membrane Water Electrolysis
Proton exchange membrane water electrolysis produces hydrogen by splitting water without carbon dioxide emissions, but it depends on expensive and vulnerable iridium catalysts. Researchers at Tohoku University developed a high-entropy perovskite catalyst that embeds iridium nanoparticles within a crystal structure to protect the metal from degradation during extended operations.
Water electrolysis offers a promising route for renewable energy integration because it responds rapidly to fluctuations in wind and solar power supply. Traditional systems rely heavily on iridium for oxygen production. However, iridium is both rare and prone to performance loss over time as it loses electrons and becomes unstable during the electrochemical reaction. To solve this degradation problem, investigators at Tohoku University designed a material that firmly anchors the active metal particles while regulating their electronic surroundings.
Crystal Structure Design and Exsolution Process
The newly engineered material combines several different metals within a single crystal site, creating multiple atomic arrangements that provide structural stability and electronic control. Distinguished Professor Hao Li of Tohoku University’s Advanced Institute for Materials Research explained that this flexibility allows researchers to adjust the material’s properties during the reaction and protect the iridium from breaking down.
To fabricate the catalyst, the research team used an exsolution process. Heating the material under specific conditions caused the internal iridium to move outward and form surface nanoparticles. Unlike conventional manufacturing methods where nanoparticles sit on top of a support layer, these particles emerge directly from the material matrix. This internal anchoring prevents the particles from moving or clumping together during extended use.
Durability Testing in PEM Water Electrolyzers
Experiments and computer simulations confirmed that the high-entropy perovskite regulates electron distribution around the embedded iridium. When tested in a PEM water electrolyzer, the system ran for more than 3,800 hours with minimal performance loss. Under more demanding operational conditions, a separate test maintained stable hydrogen production for over 3,200 hours.
How high-entropy perovskite protects iridium catalysts?
How does the high-entropy perovskite protect the iridium catalyst?
The material’s crystal structure allows multiple metals to share the same site, which regulates electron distribution around the embedded iridium and prevents it from losing electrons and becoming unstable during water electrolysis.
What manufacturing method creates the catalytic nanoparticles?
Researchers use an exsolution process by heating the material under special conditions, causing iridium from inside the structure to emerge and form surface nanoparticles that remain firmly anchored in place.
How long did the catalyst operate during laboratory testing?
The system ran for more than 3,800 hours with very little performance loss in standard tests, and operated for over 3,200 hours under more demanding conditions.
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