# Atomic-Structure Control Suppresses Nickel Dissolution, Enabling a Highly Durable Water Electrolysis Catalyst to Operate for 3,000 Hours
# Extended Catalyst Lifetime Expected to Reduce Green Hydrogen Production Costs and Support the Commercialization of Water Electrolysis Systems
CHANGWON, South Korea — Korea Institute of Materials Science (KIMS), led by President Chul-jin Choi, announced that a research team led by Principal Researcher Sung Mook Choi of the Energy & Environment Materials Research Division, in collaboration with research teams led by Professor Min Ho Seo of Pukyong National University and Professor Won Bae Kim of Pohang University of Science and Technology (POSTECH), has developed a highly durable platinum–nickel (PtNi) hydrogen evolution catalyst that suppresses nickel (Ni) leaching through atomic ordering. Nickel leaching is a major cause of performance degradation in catalysts used for anion exchange membrane water electrolysis (AEMWE). The research addresses a longstanding problem in water electrolysis catalysts, which typically lose performance during prolonged operation, by stabilizing the catalyst structure at the atomic level. When applied to a system approaching the scale of an actual hydrogen production unit, the catalyst demonstrated less than 2% performance degradation after 3,000 hours of continuous operation. The technology is expected to advance the practical application of water electrolysis catalysts for green hydrogen production.
Anion exchange membrane water electrolysis produces hydrogen by splitting water under alkaline conditions. It is attracting attention as a next-generation green hydrogen technology because it can reduce the use of expensive precious metals and lower overall system costs. However, the hydrogen evolution reaction proceeds relatively slowly in alkaline environments, creating a need for highly active catalysts. Conventional platinum–nickel catalysts, which alloy nickel with platinum, initially exhibit strong hydrogen production performance. During long-term operation, however, nickel gradually dissolves from the catalyst in the form of ions or hydroxides. This changes the catalyst composition and electronic structure, leading to rapid performance degradation.
To overcome this limitation, the research team developed an atomically ordered PtNi catalyst in which platinum and nickel atoms are arranged at well-defined lattice positions, making nickel less likely to leach from the catalyst. In conventional disordered PtNi catalysts, platinum and nickel atoms are randomly mixed, allowing nickel to escape more readily during extended operation. By arranging the two elements in an ordered intermetallic structure, the researchers significantly improved the structural stability of the catalyst. Using computational materials science, the team determined that nickel atoms are more strongly stabilized and have a higher resistance to dissolution in the ordered PtNi structure. The researchers then applied these theoretical findings to catalyst synthesis and the fabrication of water electrolysis electrodes.
The catalyst was first synthesized by reducing platinum and nickel precursors at low temperature using sodium borohydride (NaBH4). It was subsequently heat-treated under a nitrogen atmosphere to prevent unwanted reactions with air and allow the initially disordered platinum and nickel atoms to rearrange into an ordered structure. In simple terms, the heat treatment reorganized the randomly mixed atoms into a more stable configuration in which nickel remained securely within the catalyst. The resulting ordered PtNi catalyst was applied to the cathode, where hydrogen is produced in a water electrolysis system. Its performance was then progressively evaluated from half-cell testing to a single cell and, ultimately, a large-area three-cell stack.
Durability testing confirmed that the ordered PtNi catalyst retained substantially more nickel than the conventional disordered catalyst. Following the durability test, the disordered catalyst had lost approximately 54% of its initial nickel content, whereas the ordered catalyst showed a reduction of only about 9%. These results demonstrate that atomic ordering effectively suppresses nickel leaching and helps preserve the catalyst structure during prolonged operation. The research team also applied the catalyst to a large-area three-cell stack with an active area of 64 cm2 and operated it continuously for 3,000 hours, equivalent to approximately four months. Performance degradation remained below 2%, demonstrating that the catalyst can maintain stable operation over extended periods in a practical-scale water electrolysis system.
The technology is significant because it demonstrates the potential to extend catalyst lifetime in green hydrogen production facilities. Rapid catalyst degradation increases replacement and maintenance costs, making long-term durability a key requirement for the commercialization of water electrolysis systems. The developed catalyst can reduce platinum use while maintaining stable performance over extended periods. It is therefore expected to be applicable to renewable energy-linked hydrogen production facilities, distributed water electrolysis systems, and large-area electrolyzer stacks. The atomic-ordering design strategy may also be extended to other platinum–transition metal catalysts, fuel cells, and various electrochemical energy systems.
“This study is significant because we used computational science to explain how atomic ordering suppresses nickel leaching under anion exchange membrane water electrolysis conditions and then experimentally validated the mechanism through detailed catalyst analysis and 3,000 hours of operation in a commercially relevant large-area three-cell stack,” said Sung Mook Choi, principal researcher and project leader at KIMS.“By demonstrating that the material’s outstanding performance can be maintained in an actual water electrolysis system, the technology is expected to provide a foundation for accelerating the commercialization of highly durable green hydrogen production systems with reduced precious metal content,” he added.
The research was supported by the Ministry of Science and ICT through the National Research Laboratory for Hydrogen Program (H2NEXT ROUND) and the Nano and Materials Technology Development Program of the National Research Foundation of Korea, as well as KIMS’s institutional research program. The findings were published online on July 1, 2026, in Carbon Energy (Impact Factor: 24.2; top 2.9% in the Journal Citation Reports), a leading international journal in the energy field. Senior Researcher Song Jin and Researcher Jae-Yeop Jeong of KIMS, together with Minseon Park of POSTECH, served as co-first authors. Principal Researcher Sung Mook Choi of KIMS, Professor Min Ho Seo of Pukyong National University, and Professor Won Bae Kim of POSTECH served as co-corresponding authors. The research team plans to further reduce precious metal loading, improve the uniformity of large-area electrode manufacturing, and optimize stack operating conditions. It will also conduct detailed analyses of load fluctuations and long-term degradation mechanisms under practical operating environments to advance the technology toward industrial application.
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About Korea Institute of Materials Science(KIMS)
KIMS is a non-profit government-funded research institute under the Ministry of Science and ICT of the Republic of Korea. As the only institute specializing in comprehensive materials technologies in Korea, KIMS has contributed to Korean industry by carrying out a wide range of activities related to materials science including R&D, inspection, testing&evaluation, and technology support.