A “Dual Spatial Confinement” Route to Tailor Efficient Dual‐Active Sites ORR Catalyst for Rechargeable Zn‐Air Batteries

Dual active center catalysts (DACs) are effective for accelerating the sluggish kinetics of cathodic oxygen reduction reaction (ORR) in rechargeable zinc-air batteries (ZABs). However, their tendency to aggregate severely restrict the catalytic efficiency. Herein, a "dual spatial confinement" route is conceived to develop a family of well-dispersed DACs for boosting ORR activity and ZABs. During pyrolysis, the Zn vacancies generated from Zn-Zeolitic imidazolate framework (Zn-ZIF) precursors facilitate the initial incorporation and confinement of Fe/Co atoms, enabling the formation of uniformly dispersed metal sites. Subsequently, the in-situ grown N-doped carbon nanotubes (CNTs) further regulate the dual active centers (Co₃Fe₇ and Co_5.47N), ultimately yielding a highly efficient ORR catalyst. Owing to the synergistic effect between the dual active centers, the optimized Co₃Fe₇/Co_5.47N@CNT-900 catalyst exhibits superior 4e^- ORR activity. Theoretical calculations demystify that the Co₃Fe₇/Co_5.47N sites co-promote the generation of OH^- on Co centers, greatly enhance the ORR activity. When applied in rechargeable ZABs, the catalyst delivers a high power density of 168.99 mW cm^-2, a high specific capacity of 904.57 mAh g_Zn ^-1, and good cycling stability, along with fine rate capability. This work shall light a pathway towards dual active center catalysts with sterling ORR activity.