"Does Not Dissolve Even in Acidic and High-Voltage Conditions"... Korea University and KIST Develop Next-Generation Water Electrolysis Catalyst Design [Reading Science]

Solving Ruthenium Oxide Instability
Stable Operation for Over 540 Hours
Improved Efficiency in Green Hydrogen Production Expected

A Korean research team has developed a next-generation water electrolysis catalyst design technology that maintains its performance even under acidic environments and high-voltage conditions. This advancement draws attention as it may address the critical issue of catalyst degradation, which has been a major challenge in green hydrogen production.

A research team led by Professor Kwangryul Lee in the Department of Chemistry at Korea University, in collaboration with Dr. Sungjong Yoo’s team at the Korea Institute of Science and Technology (KIST) and Professor Seoin Baek’s team at the KU-KIST Graduate School of Korea University, announced on May 20 that they have proposed a nanocatalyst design strategy to simultaneously enhance both the activity and durability of acidic water electrolysis catalysts.

A schematic diagram illustrating the formation and operating principle of the catalyst developed in this study. During the heat treatment process, ruthenium on the surface of the platinum-nickel nanostructure migrates inward, forming a "mosaic-type heterointerface" where ruthenium oxide and platinum are densely connected. Provided by the research team.

The research results were published online on May 7 in Advanced Energy Materials, an international journal in the field of materials science.

Water electrolysis is a key technology that decomposes water into hydrogen and oxygen to produce green hydrogen. However, catalyst performance has been prone to rapid degradation under acidic and high-voltage conditions. In particular, the oxygen evolution reaction (OER) has been cited as a major cause of reduced energy efficiency, due to its complex reaction process and slow rate.

Existing ruthenium oxide catalysts have higher activity and lower cost compared to iridium oxide, but they have the limitation that ruthenium dissolves easily under acidic and high-potential conditions.

The research team grew ruthenium on the surface of a platinum-nickel nanostructure and, through heat treatment, achieved a ‘mosaic-type heterojunction’ structure where ruthenium oxide and platinum are densely interlocked. During this process, platinum oxidizes first and acts as a ‘buffer material’ that absorbs charge, thereby suppressing the phenomenon of ruthenium oxide transforming into an over-oxidized state and leaching out, according to the research team.

Research team photo. (From left) Yeji Park, Ph.D., Korea University & KIST (first author); Doyeop Kim, Ph.D. candidate, Department of Chemistry, Korea University (first author); Seoin Baek, Professor, KU-KIST Graduate School, Korea University (corresponding author); Seongjong Yoo, Ph.D., Hydrogen and Fuel Cell Research Group, KIST (corresponding author); Kwangryeol Lee, Professor, Department of Chemistry, Korea University (corresponding author). Courtesy of Korea University

Experimental results showed that this catalyst maintained both high activity and long-term stability even under acidic conditions. It recorded a low overpotential of 168 mV at a given current density and operated stably for over 540 hours.

The research team expects that this technology will not only improve the performance of a specific catalyst but will also be applicable to the overall design of high-performance energy catalysts.

Professor Kwangryul Lee of Korea University stated, "This case demonstrates precise control over the migration direction of atoms within the nanocatalyst, forming a high-density heterojunction structure that was difficult to achieve with conventional methods. Going forward, we plan to expand our research to develop highly active and durable catalysts that surpass commercial catalysts in actual water electrolysis systems."

This content was produced with the assistance of AI translation services.