Core-shell nanocluster catalysts enable high efficiency, low cost, and environmentally friendly hydrogen production

A Korean research team has successfully developed advanced electrochemical catalysts. This innovation is expected to lead to next-generation sustainable hydrogen production.

The newly developed catalyst features ruthenium (RU)-based nanoclusters with a core-shell structure. Despite using only minimal precious metals, it offers world-class performance and exceptional stability. Furthermore, when applied to industrial-scale water electrolytic devices, it demonstrated significant efficiency and highlighted the potential for commercial applications.

This study was published in Energy & Environmental Science.

Hydrogen is widely considered a clean energy source because it does not release carbon dioxide when burned, making it a promising alternative to fossil fuels. One of the most efficient ways to produce environmentally friendly hydrogen is by using water electrolysis, which divides water into hydrogen and oxygen.

Among the various electrolysis methods, anion-exchange membrane water electrolysis (AEMWE) is attracting attention as a next-generation technology due to its ability to generate high-purity hydrogen. However, for AEMWE to be commercially viable, a catalyst is required that provides both high efficiency and long-term stability.

Currently, platinum (PT) is the most widely used catalyst for hydrogen production, but its high cost and rapid deterioration poses serious challenges. Researchers are exploring alternatives to non-preferred metals, but these materials are usually not suitable for industrial use due to their low efficiency and low stability.

To overcome these limitations, a research team led by Professor Jin Young Kim of the Faculty of Materials Science and Engineering, collaborated with Professor Jang Woo Lee of Cookmin University and Dr Song Jung Yoo of the Korean Institute of Science and Technology (KIST) to develop a new core-shell nanocluster catalyst based on Ruten (RU).

By reducing the catalyst size to less than 2 nanometers (nm) and minimizing the amount of precious metals by one-third of those used with traditional platinum-based electrodes, the team achieved excellent performance and outperformed that of existing platinum catalysts.

The newly developed catalyst demonstrates 4.4 times the performance of platinum catalysts with the same precious metal content, setting a new benchmark for hydrogen evolution reaction efficiency. Furthermore, it recorded the highest performance ever reported among hydrogen evolution catalysts.

Its unique foam electrode structure optimizes the delivery of reactive materials and ensures excellent stability even under high current densities.

In industrial-scale AEMWE tests, the new catalyst required significantly less power compared to commercially available platinum catalysts. The results cement the potential as a game-changing solution for next-generation water electrolysis technology.

The development process involved several important innovations. First, the researchers treated the titanium foam substrate with hydrogen peroxide to form a thin layer of titanium oxide.

This was followed by doping with the transition metal molybdenum (MO). Ruthenium oxide nanoparticles with only 1-2 nm size were then uniformly deposited on the modified substrate.

Accurate low-temperature heat treatment induced atomic level diffusion, forming a core-shell structure. During the hydrogen evolution reaction, an electrochemical reduction process further strengthened the properties of the material, resulting in a ruthenium metal core encapsulated by a porous reduced titania monolayer, with metallic molybdenum atoms placed at the interface.

In the future, core-shell nanocluster catalysts are expected to significantly reduce the amount of precious metals required, ultimately reducing production costs, while significantly improving the efficiency of hydrogen production.

The combination of high performance and economic feasibility makes it a powerful candidate for use in vehicles, environmentally friendly transport systems, hydrogen power plants and hydrogen fuel cells for a variety of industrial applications.

Beyond practical applications, this breakthrough represents a major technological advance that can accelerate the transition from fossil fuel-based energy systems to a hydrogen-driven economy.

Professor Jin Young Kim highlighted the impact of the research by saying, “Even though it is small in size 2 nanometers, the core-shell catalysts show remarkable performance and stability. This breakthrough contributes greatly to the development of nanocore-shell device manufacturing technology and hydrogen production, and to approach the future of carbon-centricity.”

Meanwhile, the first author of the study, Dr. Hyun Wim, was selected for the government’s Sejong Fellowship Program and continues his research as a postdoctoral researcher in Professor Kim’s lab at Seoul National University.

His current focus is on further development and commercialization of core-shell catalyst technology.