• • Under a current density of 1 A cm−2, the Ta-doped RuO2 catalyst achieved a cell voltage of 1.704 V with a degradation rate of only 14 μV h−1, demonstrating exceptional stability for industrial PEM electrolysis.
• • Tantalum incorporation suppressed the formation of high-valence RuO4 phases and reduced changes in the cathodic charge (q* cathodic), as confirmed by in situ Raman spectroscopy, thereby mitigating the primary corrosion pathway of RuO2.
• • Quantum mechanical calculations using the grand canonical quantum mechanics (GCQM) method showed that Ta preferentially deposits on Ru(100) surface substituting unsaturated coordination sites (CUS) and occupies bridge sites on Ru(110), enhancing intrinsic activity and stability.
• • Kilogram-scale production of TaRuOx was achieved via a sol-gel method, enabling large-scale photovoltaic water electrolysis tests, which validates the scalability and industrial viability of the catalyst synthesis.