New Energies, new possibilities

Green hydrogen production technology, which utilizes renewable energy to produce eco-friendly hydrogen without carbon emissions, is gaining attention as a core technology for addressing global warming. Green hydrogen is produced through electrolysis, a process that separates hydrogen and oxygen by applying electrical energy to water, requiring low-cost, high-efficiency, high-performance catalysts. A research team led by Dr. Na Jongbeom and Dr. Kim Jong Min from Korea Institute of Science and Technology's Center for Extreme Materials Research has developed next-generation water electrolysis catalyst technology. This technology integrates a single-atom "All-in-one" catalyst precisely controlled down to the atomic level with binder-free electrode technology. The study is published in the journal Advanced Energy Materials.

A key feature of this technology is its ability to stably perform both hydrogen evolution and oxygen evolution reactions simultaneously on a single electrode.

Existing electrolysis systems had limitations requiring different catalysts and electrode structures for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), necessitating the use of large quantities of expensive precious metals. Additionally, the binder used to fix the catalyst to the electrode posed problems, including reduced electrical conductivity and catalyst detachment during long-term operation.

Schematic illustrating the fabrication of a single-atom catalyst by introducing a molecular anchoring agent (phytic acid) into a manganese (Mn)-nickel (Ni) layered double hydroxide (LDH) framework, enabling uniform immobilization of iridium (Ir) at the atomic scale. The engineered single-atom hosting sites stably disperse iridium single atoms, resulting in an 'All-in-one' anion exchange membrane (AEM) water electrolysis catalyst capable of simultaneously driving both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) with a single catalyst. Credit: Korea Institute of Science and Technology
KIST researchers utilized atomic-level precision control technology to uniformly disperse iridium (Ir) atoms across the surface of a manganese (Mn)-nickel (Ni)-based layered double hydroxide (LDH) support incorporating phytic acid. This strategy replaced the conventional use of bulk iridium precious metal. By maximizing the number of active sites for water-splitting reactions with minimal iridium, this approach is analogous to evenly spreading fine grains of sand over a large surface rather than relying on a single large rock.

In particular, the iridium single atom acts as a direct active site for the hydrogen evolution reaction through its strong interaction with the support, while simultaneously enhancing the catalytic performance of the nickel-based active site where the oxygen evolution reaction occurs. Thus, a single-atom catalyst has realized bifunctional catalytic characteristics, exhibiting suitable reactivity for both reactions.

Furthermore, the research team applied a method of directly growing the catalyst on the electrode surface, achieving an electrode structure that does not require a separate binder. This significantly improved electrical conductivity and ensured excellent durability even during long-term operation.

(Left) High-resolution scanning transmission electron microscopy (HR-STEM) images confirm the uniform dispersion of iridium (Ir) single atoms without detectable aggregation. (Right) Compared with representative state-of-the-art catalysts, the long-term anion-exchange membrane (AEM) water electrolysis performance of the 'All-in-one' single-atom catalyst developed in this work exhibits markedly lower degradation during extended operation, even at high current density (1.0 A·cm⁻²), indicating robust operational stability relevant to practical electrolysis conditions. Credit: Korea Institute of Science and Technology
This technology significantly reduces precious metal usage to within 1.5% compared to existing precious metal catalysts while achieving outstanding performance in both hydrogen and oxygen evolution reactions. In addition, it demonstrates high stability with minimal performance degradation even after continuous operation for over 300 hours in an anion exchange membrane (AEM) water electrolysis system.

This research outcome demonstrates the technical feasibility of simultaneously enhancing the economic viability and durability of electrolysis systems by minimizing precious metal usage and simplifying electrode structures. It is expected to significantly contribute to the commercialization of green hydrogen production and the reduction of hydrogen production costs in the future.

Dr. Na Jongbeom of KIST stated, "This work is highly significant as it resolves the two essential reactions for hydrogen production using a single catalyst while reducing precious metal consumption. This technology will accelerate the commercialization of water electrolysis devices and provide substantial support for expanding hydrogen energy."https://phys.org/news/2026-02-atom-power-sides.html