Interfacing MnO and FeCo alloy inside N-doped carbon hierarchical porous nanospheres derived from metal-organic framework to boost high-performance oxygen reduction for Zn-air batteries.

Efficient and strong non-precious metal catalysts are urgently needed for the oxygen reduction reaction (ORR). Here, a facile hydrothermal-pyrolysis process was implemented to engineer CoFe-MnO heterointerfaces encapsulated in N-doped carbon (CFM-NC) nanospheres with a metal-organic framework (MOF) as the precursor. Due to heterointerfaces and hierarchical porosity, CFM-NC-800 exhibited superior ORR activity (half-wave potential of 0.86 V) and durability (30 000 s). Importantly, CFM-NC-800-based Zn-air batteries (ZABs) were capable of extending the outstanding performance, with a high power density of 260 mW cm -2 and a specific capacity of 812 mA h g -1 . Furthermore, the CFM-NC-800-RuO 2 -based ZABs showed remarkable stability (480 cycles), outperforming Pt/C-RuO 2 (360 cycles). This work highlights the effects of CoFe-MnO heterointerfaces and hierarchical porosity in ORR electrocatalysis, thereby providing a new avenue for energy conversion and storage.