Newswise — Lowering the cost of green hydrogen production requires catalysts that produce hydrogen efficiently while using smaller amounts of expensive precious metals. A Korean research team has developed a catalyst that brings three or four ruthenium (Ru) atoms together so they can work cooperatively. The catalyst achieved hydrogen production performance comparable to that of a commercial platinum catalyst while using only one-quarter as much precious metal, potentially helping to lower the cost of green hydrogen production.
KAIST (President Choongsik Bae) announced on October 28 that a research team led by Professor Jinwoo Lee from the Department of Chemical and Biomolecular Engineering has developed a high-performance water electrolysis catalyst based on an “atom-layer neighbor” structure. The work was carried out in collaboration with Professor Hyungjun Kim from the Department of Chemistry, Professor Jang Yong Lee from Konkuk University, Dr. Joonhee Moon from the Korea Basic Science Institute (KBSI), and Dr. Sungjun Kim from the Korea Research Institute of Chemical Technology (KRICT).
Water electrolysis uses electricity to split water into hydrogen and oxygen. When powered by renewable energy sources such as solar and wind, the process produces “green hydrogen” with low carbon emissions. However, catalysts for the hydrogen-producing reaction rely on expensive precious metals, creating a need for technologies that maintain performance while reducing precious metal use.
In conventional precious metal nanoparticle catalysts, many atoms are clustered together, leaving those buried inside the particles largely unable to participate in the reaction. As a result, only a fraction of the precious metal is actively used. To address this problem, researchers have explored “single-atom catalysts,” in which individual metal atoms are dispersed across a support. However, their isolated arrangement can limit performance in reactions that require several atoms to work together.
The research team sought to maximize the use of each atom while enabling neighboring atoms to cooperate. The team created “atom-layer neighbors,” small groups of ruthenium atoms arranged in a layer just one atom thick. This structure keeps the atoms close enough to work together in the reaction without forming large particles.
Maintaining this arrangement requires a support—a base material that holds the ruthenium atoms in place. During the initial stage of catalyst synthesis, the researchers used molecular interactions to prevent the atoms from aggregating into large particles. During subsequent heat treatment, strong metal–support interactions anchored the atoms to a tungsten carbide (WCₓ) support. The team also varied the number of atoms in each group to identify the most effective structure for hydrogen production.
The researchers also optimized the local environment surrounding the active atoms. Hydroxyl species (OH) on the support surface strengthened the hydrogen-bond network among water molecules, facilitating faster proton (hydrogen ion) transfer. By controlling both the arrangement of the catalytically active atoms and the interactions among surrounding water molecules, the team enabled the reaction to proceed efficiently.
When tested in an anion-exchange membrane water electrolyzer (AEMWE) cell, the catalyst achieved a current density of 9.82 amperes per square centimeter (A/cm²) at 2.0 volts (V) and 80°C. Current density measures the current flowing per unit of electrode area and indicates the rate of hydrogen production over that area. The catalyst delivered performance comparable to that of a commercial platinum catalyst while using 75% less precious metal. Its catalytic activity per unit mass of precious metal was approximately four times that of the platinum catalyst.
The team also evaluated the catalyst’s durability during extended operation. In a 500-hour continuous operation test, its performance loss was about half that of the platinum catalyst used for comparison. The results demonstrate that the catalyst can deliver high performance with a small amount of precious metal while maintaining stability over extended operation times.
The findings could help reduce precious metal use in hydrogen production equipment and lower catalyst replacement and maintenance costs. If the performance is validated at a larger scale and over longer operating periods, the catalyst could help lower the cost of green hydrogen production.
“In this study, we brought small groups of precious metal atoms together and optimized the surrounding environment for water reactions, enabling efficient and sustained hydrogen production with a small amount of precious metal,” said Research Professor Seongbeen Kim, a co-first author of the study. He added that the team hopes the findings will help reduce precious metal use in hydrogen production equipment and guide efforts to improve other catalysts.
Professor Kim and researchers Hyunwoo Jun and Jihye Park of KAIST, together with Dr. Sungjun Kim of KRICT, contributed as co-first authors. The findings were published online in Nature Communications on September 22 (Vol. 17, Article No. 11021).
※ Paper title: Stabilizing ruthenium atom layer neighbors through molecular and metal support interactions for water electrolyzers
※ DOI: https://doi.org/10.1038/s41467-026-78037-3
This research was supported by National Research Foundation of Korea (NRF) grants funded by the Ministry of Science and ICT (MSIT) (RS-2023-00235596, RS-2026-25474505, RS-2026-25477690, and RS-2024-00466554) and by the Basic Science Research Program of the Korea Basic Science Institute (KBSI) (C526111).
