Breaking the Activity–Stability Scaling in RuO ₂ via Single‐ and Dual‐Doping Strategies

ABSTRACT Ruthenium dioxide (RuO 2 ) is a highly active electrocatalyst for the acidic oxygen evolution reaction (OER), yet its practical application in proton exchange membrane water electrolysis is hindered by poor stability arising from Ru overoxidation, lattice oxygen participation, and subsequent dissolution. In recent years, heteroatom doping has emerged as an effective strategy to tune the electronic structure and improve catalytic performance. This review systematically summarizes single and dual doping in the RuO 2 lattice, focusing on their roles in modulating adsorption energies, defect chemistry, and lattice stability. Although single‐element doping, including nonmetals, transition metals, and rare‐earth metals, can enhance their catalytic activity and durability, it often fails to overcome an inherent activity–stability trade‐off. In contrast, dual doping enables synergistic regulations of the electronic structure and reaction pathways, facilitating controlled oxygen vacancies, suppressing lattice oxygen involvement, and promoting more stable mechanisms. Finally, key challenges and future directions are highlighted, emphasizing the need for atomic‐level understanding and scalable catalyst design. This review provides a unified framework for developing highly efficient and durable RuO 2 ‐based catalysts for acidic OER.