Multi-Step Screening-Guided Core-Shell RuO₂@TaO_x Nanorods Electrocatalyst for Acidic Oxygen Evolution Reaction

In the acidic oxygen evolution reaction (OER), the exploration of highly efficient and stable electrocatalysts is essential for the environmentally friendly production of hydrogen. Although RuO₂ exhibits high catalytic activity, its solubility and corrosion in acidic environments are of concern. In this study, high-melting-point metal oxides were multi-step rationally screened as protective layers for RuO₂ to identify their roles in the acidic OER process. Among them, Ta-related oxide was selected as the best candidate. To demonstrate the theoretical predictions, RuO₂@TaO_x with a core-shell structure was deployed, which exhibited low overpotentials of 163 and 232 mV at 10  and 100 mA cm^-2, respectively. In fact, the dense amorphous TaO_x layer effectively prevented the dissolution of RuO₂ and optimized the charge transfer through interfacial synergy, significantly improving both the activity and durability of OER. Meanwhile, the operando quick X-ray absorption spectroscopy (Quick-XAS) confirmed that Ru served as the active site during OER, while Ta inhibited the over-oxidation of Ru, correlating with theoretical considerations. This study provides a new paradigm using targeted computational screening to guide the design of advanced catalysts, and serves as a proof-of-concept for the deployment of high-melting-point metal oxides as a protective layer for RuO₂ in the acidic OER.