SEOUL – Researchers at the Korea Advanced Institute of Science & Technology (KAIST) have announced a significant breakthrough in proton exchange membrane water electrolysis (PEMWE), a critical technology for producing high-purity hydrogen. Published in Energy & Environmental Science, their findings address a major cost barrier hindering the widespread commercialization of green hydrogen production, potentially accelerating the global transition to a hydrogen economy.

PEMWE is highly regarded for its efficiency in splitting water into hydrogen and oxygen using electricity, yielding high-purity hydrogen. However, its commercial viability has been severely limited by the reliance on expensive precious metal catalysts, such as platinum and iridium oxide, which are essential for optimal performance. These high material costs have posed a substantial bottleneck for large-scale adoption.

The KAIST team, led by Professor Hee-Tak Kim, focused on understanding why iridium oxide catalysts lose effectiveness without costly platinum coatings. Their investigation pinpointed “electron transition resistance” as the core issue, a problem they discovered could be mitigated by precisely controlling the size of the iridium oxide catalyst. Through extensive experimentation, the researchers determined that catalysts with a size of 20 nanometers or larger significantly reduce the need for precious metal co-catalysts. Furthermore, they successfully optimized the design structure to resolve inherent conflicts between catalyst activity and conductivity, enhancing overall system performance.

“This research presents a new interface design strategy that can resolve the interfacial conductivity problem, which was a bottleneck in high-performance water electrolysis technology,” stated Professor Kim. He added, “By securing high performance even without expensive materials like platinum, it will be a stepping stone closer to realizing a hydrogen economy.”

Hydrogen is increasingly viewed as a pivotal clean energy carrier, capable of fueling diverse applications from transportation to industrial processes, with water as its primary emission upon combustion. The challenge, however, lies in developing cost-effective and environmentally friendly production methods. While the KAIST team champions improved PEMWE, other research groups are exploring alternative solutions; for instance, a European organization, Anemel, is investigating the use of more abundant metals like nickel, and a Japanese group has proposed novel electrochemical water splitting methods. The KAIST breakthrough, by directly addressing the high material cost of PEMWE, positions this method as a strong contender for scalable and economically viable green hydrogen production.