Making Hydrogen and Oxygen at the Same Time with Single Atoms [Reading Science]

KIST Develops All-in-one Single-atom Water Electrolysis Catalyst, Lowering the Barrier to Green Hydrogen Commercialization

A path has opened to simplify the water electrolysis catalyst structures that have long been considered a bottleneck in green hydrogen production. It is an all-in-one single-atom catalyst technology that enables both the hydrogen and oxygen evolution reactions to occur simultaneously on a single electrode.

The Korea Institute of Science and Technology (KIST) announced on February 8, 2026 that a research team led by Dr. Na Jongbeom and Dr. Kim Jongmin at the Extreme Conditions Materials Research Center has developed a next-generation water electrolysis catalyst material by combining a single-atom catalyst, precisely controlled at the single-atom level, with an electrode technology that does not use binders.

Schematic of a single-atom catalyst that uniformly anchors iridium at the single-atom level using phytic acid on a manganese-nickel layered double hydroxide structure. An all-in-one anion exchange membrane water electrolysis configuration was implemented that performs hydrogen and oxygen evolution reactions simultaneously with a single catalyst. Provided by the research team.

Green hydrogen is produced by water electrolysis, in which water is split using electricity. In conventional water electrolysis systems, different catalysts and electrode structures are required for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), and this has led to increased consumption of expensive precious metals such as iridium. There have also been recurring problems in which the binders used to fix catalysts onto the electrodes hinder electron transport or cause catalyst detachment during long-term operation.

Instead of using iridium (Ir) in bulk form, the research team dispersed it at the atomic level and uniformly anchored it on the surface of a manganese-nickel-phytic-acid-based support. This maximized the reactive surface area with only a minute amount of precious metal. The single iridium atoms act as direct active sites for the hydrogen evolution reaction, while at the same time enhancing the performance of the nickel-based active sites where the oxygen evolution reaction occurs, thereby realizing bifunctionality in which a single catalyst carries out both reactions.

In addition, the team adopted a binder-free electrode structure in which the catalyst is grown directly on the electrode surface, thereby improving electrical conductivity and resolving durability issues. As a result, they reduced the precious-metal loading to within 1.5% of that in conventional systems, while demonstrating stability in an anion exchange membrane water electrolysis (AEMWE) system with almost no performance degradation even after more than 300 hours of continuous operation.

Conventional anion-exchange membrane water electrolysis requires different catalysts at the anode and cathode, making the system complex and costly (left). A single-atom all-in-one catalyst drives both reactions with a single catalyst, simplifying the structure, reducing precious-metal and manufacturing costs, and securing long-term stability (right). Provided by the research team.

This technology is significant in that it simultaneously achieves simplification of the electrode structure and minimization of precious-metal use, thereby enhancing both the economic feasibility and durability of water electrolysis systems. The researchers believe it has strong potential for application under the high-power, long-term operating conditions required in large-scale green hydrogen production processes.

Na Jongbeom, Senior Researcher at KIST, said, "It is meaningful that we have greatly reduced the amount of precious metals used while enabling a single catalyst to handle the two reactions required for hydrogen production," adding, "This can help accelerate the commercialization of water electrolysis devices and lower the unit cost of hydrogen production."

This research was carried out with support from the Ministry of Science and ICT under KIST's major projects, the Excellent Young Researcher Program, the DACU Source Technology Development Project, and the Korea-U.S.-Japan International Joint Research Program. The results were published in Advanced Energy Materials, an international journal in the energy field.