Noble‐Metal‐Assisted Fast Interfacial Oxygen Migration with Topotactic Phase Transition in Perovskite Oxides

Abstract Transition‐metal perovskite oxides constitute a series of functional material systems for electronics, catalysis, and energy‐conversion processes, in which oxygen migration and evolution play a key role. However, the stable metal–oxygen (MO) bond forms a large energy barrier inhibiting ion diffusion. Therefore, seeking efficient and facile approaches to accelerate oxygen kinetics has become a significant issue. Here, the interaction (interfacial charge transfer and cooperative bonding) between noble metal (Pt, Ag) and perovskites oxide (SrCoO3−δ) is employed to weaken the (MO) bond and decrease the energy barrier of oxygen migration. Noble metal layers serving as oxygen pumps can continuously extract oxygen from oxide films to the atmosphere. The temperature of the topotactic phase transition from perovskite (SrCoO3) to brownmillerite (SrCoO2.5) is remarkably lowered from ≈200 °C to room temperature. Furthermore, this approach can also be applied to SrFeO3 for similar topotactic phase reduction by moderate thermal activation. The finding of this study paves a promising and general pathway to achieve fast oxygen migration in perovskite oxides, with important application prospects in low‐temperature electrodes and high‐activity catalysis interface.