image: LSV curves (a), Tafel slope (b) and EIS Nyquist plots (c) of RhRu3Ox, Hom-RuO2 and Com-RuO2. The solution resistance was determined from the intersection of the EIS curve with the real axis when the imaginary part (Z″) equals zero, yielding a value of 25.0 ± 0.4Ω. (d) C2dl plots calculated from CV curves. (e) Tafel plots of RhRu3Ox at different temperatures. (f) Arrhenius plot of OER exchange current density of RhRu3Ox and Hom-RuO2 CoP.
Credit: ©Heng Liu et al.
The oxygen evolution reaction is more relevant to your daily life than you would think. It is used in many electrochemical devices, such as batteries. However, this reaction still has a lot of room for improvement that would allow for it to be applied at a larger scale in next-gen technology. To achieve this, researchers at Tohoku University demonstrated an effect that influences the stability of catalysts - the key to making this oxygen evolution reaction more efficient.
The findings were posted in Nature Communications on October 20, 2025.
The research team used a home-made operando differential electrochemical mass spectrometry system to examine how RhRu3Ox behaves in the oxygen evolution reaction. Their findings showed a temperature-dependent mechanism evolution effect, which means that a certain stage of the reaction is triggered by temperature. The revelation of this effect will help researchers understand how to manipulate this pathway in order to create more stable catalysts.
"We found that this catalyst tends towards different reaction mechanisms at high versus low temperatures, which we can now use to our advantage to try and get the outcome that we want," explains Heng Liu (Advanced Institute for Materials Research (WPI-AIMR).
Since practical implementation is also important, they evaluated the stability of RhRu3Ox. Remarkably, it remained stable for over 1000 hours at room temperature (current density: 200mA cm−2).
To advance this research further, future work should focus on optimizing the F doping levels to systematically enhance catalytic performance and durability under commercial-scale PEM electrolyzer conditions.
This work represents considerable advancement in the fundamental research of TMPs-based hydrogen evolution reaction (HER) catalysts, which paves the way for the rational design of novel highly-efficient, non-noble metal-based cathodes for commercial applications. These catalysts hold tremendous potential as a way to help reduce our reliance on fossil fuels and generate energy in an environmentally-friendly manner.
About the World Premier International Research Center Initiative (WPI)
The WPI program was launched in 2007 by Japan's Ministry of Education, Culture, Sports, Science and Technology (MEXT) to foster globally visible research centers boasting the highest standards and outstanding research environments. Numbering more than a dozen and operating at institutions throughout the country, these centers are given a high degree of autonomy, allowing them to engage in innovative modes of management and research. The program is administered by the Japan Society for the Promotion of Science (JSPS).
See the latest research news from the centers at the WPI News Portal: https://www.eurekalert.org/newsportal/WPI
Main WPI program site: www.jsps.go.jp/english/e-toplevel
Advanced Institute for Materials Research (AIMR)
Tohoku University
Establishing a World-Leading Research Center for Materials Science
AIMR aims to contribute to society through its actions as a world-leading research center for materials science and push the boundaries of research frontiers. To this end, the institute gathers excellent researchers in the fields of physics, chemistry, materials science, engineering, and mathematics and provides a world-class research environment.
AIMR site: https://www.wpi-aimr.tohoku.ac.jp/en/
Journal
Nature Communications
Article Title
Researchers Find That Temperature Matters for RhRu₃Ox During Acidic Water Oxidation
Article Publication Date
20-Oct-2025