Reviewed by Lexie CornerApr 24 2025
Researchers from Tohoku University have developed a new catalyst structure designed to improve the efficiency and cost-effectiveness of hydrogen production through water electrolysis. The material consists of mesoporous single-crystalline Co3O4 doped with atomically dispersed iridium (Ir), engineered to enhance performance in the acidic oxygen evolution reaction (OER).
Deactivation of Co3O4 acidic OER catalyst. Image Credit: ©Yong Wang et al.
Iridium is well-known for its excellent performance in the oxygen evolution reaction (OER), but is limited by its scarcity and high cost. A major challenge in scaling up electrolyzer technologies is using iridium efficiently while maintaining long-term stability. This study addresses that challenge by introducing a material that optimizes iridium utilization at the atomic level.
The catalyst features a mesoporous spinel structure that supports a high iridium loading (13.8 wt%) without forming large iridium clusters. This design enables the creation of Co-Ir bridge sites, which exhibit high intrinsic activity under acidic OER conditions.
Computational analysis indicates that under reaction conditions, oxygen intermediates (O*) fully cover the Co3O4 surfaces, passivating the Co sites. However, iridium doping reactivates these sites and enhances the catalyst's structural integrity.
The leaching of both iridium and cobalt during the reaction was significantly reduced. Compared to traditional Ir/Co3O4 catalysts, the loss of iridium and cobalt was reduced by approximately one-fourth and one-fifth, respectively. The catalyst also demonstrated stable performance for over 100 hours, maintaining an overpotential (η₁₀) of only 248 mV.
The mesoporous architecture plays a crucial role. It provides space for single-atom Ir loading and helps create a stable environment for catalytic activity.
Hao Li, Professor, Tohoku University
The research combines experimental data with computational modeling, with key findings made available through the Digital Catalysis Platform (www.digcat.org), a resource developed by the Hao Li Lab to assist in catalyst discovery.
This work was supported by the Tohoku University Support Program. Future research will focus on optimizing the doping level, scaling up the synthesis process, and exploring the integration of the catalyst into commercial electrolyzer systems.
Journal Reference:
Wang, Y., et al. (2025). Mesoporous Single-Crystalline Particles as Robust and Efficient Acidic Oxygen Evolution Catalysts. Journal of the American Chemical Society. doi.org/10.1021/jacs.4c18390.