A joint research team led by Professor Hyung Mo Jeong from the School of Mechanical Engineering at Sungkyunkwan University (SKKU) and Professor Ji Hoon Lee from the School of Materials Science and Engineering at Kyungpook National University has developed a highly efficient, non-precious metal water-splitting catalyst. By precisely controlling the bond spacing at the atomic level, the team successfully engaged the "lattice oxygen" hidden deep within the material to participate directly in the chemical reaction.
Water electrolysis, the process of splitting water to produce pure hydrogen without emitting greenhouse gases, is considered a dream technology for achieving carbon neutrality. However, the oxygen evolution reaction (OER) that occurs during this process is inherently sluggish. This slow reaction rate acts as a major "bottleneck" that degrades the overall efficiency of hydrogen production. To solve this, conventional systems have heavily relied on expensive precious metal catalysts such as iridium (Ir) or ruthenium (Ru), which significantly increases production costs.
To overcome these limitations, the joint research team introduced a "top-down materials design strategy." Using electrochemical methods, the researchers successfully fragmented conventional bulk cobalt oxide into ultra-fine nanoclusters measuring under 2 nanometers (nm). During this process, they finely adjusted the atomic bond length between the cobalt metal and oxygen atoms, contracting it by approximately 0.1 angstroms (Å, one ten-billionth of a meter). High-performance structural analyses at the Pohang Accelerator Laboratory (PAL) verified for the first time globally that an engineered bond length of 2.03 Å is the optimal condition for inducing an entirely new reaction pathway.
The core of this technology lies in strengthening the metal-oxygen interactions, forcing the "lattice oxygen"—which typically remains inert within the catalyst's internal structure—to actively engage in the reaction. The newly developed nanocatalyst demonstrated outstanding performance, operating at a lower energy level than expensive commercial Ir catalysts. Furthermore, when applied to actual systems, it proved its robust durability by operating for over 100 hours under high-current conditions without degradation, and also demonstrated excellent charging stability in next-generation zinc-air batteries.
Professor Hyung Mo Jeong explained, "The key point of this research is that we demonstrated the ability to completely alter the catalytic reaction pathway itself by finely controlling the bond distance at the atomic level. Beyond replacing cost-prohibitive precious metals for high-efficiency green hydrogen production, this technology will serve as a crucial benchmark for accelerating the commercialization of various next-generation eco-friendly energy devices."
This research was supported by the Ministry of Science and ICT and the National Research Foundation of Korea. The groundbreaking results were published in Applied Catalysis B: Environment and Energy, a top-tier international journal in the environmental and energy material sciences.
