A new catalyst design offers a promising approach to enhance hydrogen production efficiency through water electrolysis. The research focuses on a mesoporous single-crystalline Co3O4 structure doped with atomically dispersed iridium, specifically tailored for the acidic oxygen evolution reaction (OER). Iridium, known for its OER performance, presents challenges due to its scarcity and cost. However, by maximizing atomic-level efficiency through high Ir loading and the formation of Co-Ir bridge sites, the catalyst demonstrates high intrinsic activity under acidic OER conditions. Computational analysis highlights the catalyst's ability to reactivate Co sites and maintain structural integrity, reducing leaching of Ir and Co during reaction. Notably, the catalyst shows a significant decrease in Ir and Co loss compared to conventional catalysts, with consistent performance over 100 hours at a low overpotential. Professor Hao Li, leading the study, emphasizes the importance of the mesoporous architecture in enabling stable catalytic activity. The research, supported by the Tohoku University Support Program, combines experimental and computational approaches and shares key findings through the Digital Catalysis Platform. Future endeavors will concentrate on optimizing the doping level, scaling up synthesis methods, and integrating the catalyst into commercial electrolyzer systems, aiming for more cost-effective hydrogen production.