Reviewed by Lexie CornerMar 24 2025
An international team of researchers from Seoul National University, the Korea Institute of Science and Technology (KIST), and Kookmin University has developed an advanced electrochemical catalyst that could significantly contribute to sustainable hydrogen production.
The study, published in Energy & Environmental Science, was led by Professor Jin Young Kim from the Department of Materials Science and Engineering, in collaboration with Professor Chan Woo Lee from Kookmin University and Dr. Sung Jong Yoo from KIST.
The newly developed catalyst, based on a ruthenium (Ru) nanocluster with a core-shell structure, offers high performance and stability while using minimal amounts of precious metals. It demonstrated excellent efficiency when tested with large-scale water electrolysis equipment, suggesting its potential for commercial applications.
Hydrogen, as a clean energy source with no carbon dioxide emissions when burned, is seen as a promising alternative to fossil fuels. Water electrolysis, which splits water into hydrogen and oxygen using electricity, is one of the most effective methods for producing hydrogen. Among the various electrolysis technologies, Anion Exchange Membrane Water Electrolysis (AEMWE) has emerged as a next-generation solution due to its ability to produce high-purity hydrogen. However, AEMWE requires catalysts that combine high efficiency with long-term stability for commercialization.
Currently, platinum (Pt) is the most widely used catalyst for hydrogen production, but it is costly and prone to degradation. While non-precious metal substitutes have been explored, these materials typically have low stability and efficiency.
To overcome these challenges, the research team developed a core-shell nanocluster catalyst using ruthenium (Ru), which is more than twice as affordable as platinum. By reducing the catalyst size to less than 2 nm and using only one-third of the precious metal typically required for platinum-based electrodes, the team achieved a significant improvement in performance. The new catalyst outperformed platinum catalysts by a factor of 4.4 in terms of hydrogen evolution reaction efficiency, setting a new benchmark for hydrogen production.
The catalyst’s exceptional stability, even at high current densities, is ensured by its unique foam electrode structure, which optimizes the supply of reaction materials. In industrial-scale AEMWE testing, the new catalyst used significantly less power than commercial platinum catalysts, indicating its potential to advance next-generation water electrolysis technology.
The development process involved several key innovations. The researchers first applied hydrogen peroxide to a titanium foam substrate to create a thin layer of titanium oxide. Doping with molybdenum (Mo) followed, and the substrate was then coated with ruthenium oxide nanoparticles, which were only 1-2 nm in size. A core-shell structure was formed through precise low-temperature thermal treatment, and the material's properties were further enhanced by an electrochemical reduction process during the hydrogen evolution reaction.
Looking ahead, the core-shell nanocluster catalyst is expected to reduce the amount of precious metal required for hydrogen production while enhancing efficiency, which could lower production costs. Due to its high performance and cost-effectiveness, this catalyst is a strong candidate for use in hydrogen fuel cells for automobiles, hydrogen power plants, and other industrial applications.
In addition to its practical applications, this discovery represents a technological breakthrough that could accelerate the transition from fossil fuel-based energy systems to hydrogen-powered economies.
The core-shell catalyst, despite being smaller than 2 nm, demonstrates remarkable performance and stability. This breakthrough will contribute significantly to the development of nano core-shell device fabrication technology and hydrogen production, bringing us closer to a carbon-neutral future.
Jin Young Kim, Professor, Department of Materials Science and Engineering, Seoul National University
The study's first author, Dr. Hyun Woo Lim, is a postdoctoral fellow in Professor Kim's lab at Seoul National University. He was selected for the government's Sejong Fellowship Program. His current focus is on advancing and commercializing core-shell catalyst technology.
Journal Reference:
Lim, H. W., et al. (2025) A ruthenium-titania core-shell nanocluster catalyst for efficient and durable alkaline hydrogen evolution. Energy & Environmental Science. doi.org/10.1039/d4ee04867a.