Improving activity and stability of Ruthenium (Ru)-based catalysts in acidic environments is eager to replace more expensive Iridium (Ir)-based materials as practical anode catalyst for proton-exchange membrane water electrolyzers (PEMWEs). Here, a bicontinuous nanoreactor composed of multiscale defective RuO₂ nanomonomers (MD-RuO₂-BN) is conceived and confirmed by three-dimensional tomograph reconstruction technology. The unique bicontinuous nanoreactor structure provides abundant active sites and rapid mass transfer capability through a cavity confinement effect. Besides, existing vacancies and grain boundaries endow MD-RuO₂-BN with generous low-coordination Ru atoms and weakened Ru-O interaction, inhibiting the oxidation of lattice oxygen and dissolution of high-valence Ru. Consequently, in acidic media, the electron- and micro-structure synchronously optimized MD-RuO₂-BN achieves hyper water oxidation activity (196 mV @ 10 mA cm⁻²) and an ultralow degradation rate of 1.2 mV h⁻¹. A homemade PEMWE using MD-RuO₂-BN as anode also conveys high water splitting performance (1.64 V @ 1 A cm⁻²). Theoretical calculations and in-situ Raman spectra further unveil the electronic structure of MD-RuO₂-BN and the mechanism of water oxidation processes, rationalizing the enhanced performance by the synergistic effect of multiscale defects and protected active Ru sites.

提高钌 (Ru) 基催化剂在酸性环境中的活性和稳定性，迫切需要取代更昂贵的铱 (Ir) 基材料作为质子交换膜水电解槽 (PEMWE) 的实用阳极催化剂。在此，构想并通过三维断层重建技术证实了由多尺度缺陷RuO ₂纳米单体（MD-RuO ₂ -BN）组成的双连续纳米反应器。独特的双连续纳米反应器结构通过空腔限制效应提供丰富的活性位点和快速传质能力。此外，空位和晶界的存在赋予MD-RuO ₂ -BN大量的低配位Ru原子，减弱了Ru-O相互作用，抑制了晶格氧的氧化和高价Ru的溶解。因此，在酸性介质中，电子结构和微观结构同步优化的MD-RuO ₂ -BN实现了超水氧化活性（196 mV @ 10 mA cm ^-2 ）和1.2 mV h ^-1的超低降解率。使用MD-RuO ₂ -BN作为阳极的自制PEMWE也具有高水分解性能（1.64 V @ 1 A cm ^-2 ）。理论计算和原位拉曼光谱进一步揭示了MD-RuO ₂ -BN的电子结构和水氧化过程的机制，合理化了多尺度缺陷和受保护的活性Ru位点的协同效应增强的性能。