Self-Optimized Interfacial Co–O–Ru Motifs of Hollow Nanotube Composites Trigger Interfacial Lattice Oxygen Participation and Diffusion

Lattice oxygen participation mechanism (LOM) can break the conventional adsorption scaling limitations to boost electrocatalysis performance and has been utilized to design promising single-phase oxides that generally show favorable bulk oxygen-ion diffusion capability. In pure-phase materials, bulk oxygen vacancies could act as oxygen-ion diffusion channels, implying rich bulk oxygen vacancies at the interfaces of hybrid-phase composites may further boost LOM. Here, by designing hybrid Co 2.5 Ru 0.5 O x hollow nanotubes with rich two-phase interfaces, we report a phenomenon of interfacial LOM. Such hollow nanotubes (∼10 nm wall thickness), composed of spinel Co 3 O 4- x -rutile RuO 2- x interfaces, exhibiting a low overpotential of 430 mV and a long-term stability of 1000 h at 500 mA cm –2 for oxygen-evolving reaction (OER) in near-industrial alkaline solutions (6 M KOH). The constructed anion exchange membrane electrolyzer requires only 1.82 V to achieve a 1 A cm –2 . Interfacial Co/Ru atomic interactions trigger Co–O–Ru motifs to undergo self-optimization during OER through oxidizing Co/Ru ions and narrowing bond length to create short synergetic active sites, while interfacial oxygen vacancies act as ion-diffusion pathways. Combined mechanism experiments and computations unravel the exceptional interfacial LOM processes. Additionally, the hollow nanotube structure promotes OH – adsorption, serving as a beneficial driving force for interfacial LOM.