Controllable fabrication of Fe-N-C based single-atom catalysts (SACs) for enhanced electrocatalytic performance is highly desirable but still challenging.Here,an in situ surface-confined strategy was demonstrated for the synthesis of single atomic Fe-N4 on N-doped carbon nanoleaves (L-FeNC).The in situ generated Zn3[Fe(CN)6]2 could not only serve as a protection layer against collapse of nanoleaves but also provide abundant Fe source for the formation of Fe-N moieties during pyrolysis,leading to high surface area and high graphitization degree of L-FeNC simultaneously.Benefiting from abundant Fe-N4 active sites,enhanced mass and charge transfer,the as-prepared L-FeNC manifested a half-wave potential of 0.89 V for oxygen reduction reaction (ORR) in 0.1 M KOH.A maximum power density of 140 mW cm-2 and stable discharge voltage even after operation for 50,000 s have been demonstrated when the L-FeNC was used as air cathode for Zn-air battery.This work not only provided a unique surfaceconfined strategy for the synthesis of two-dimensional nanocarbons,but also demonstrated the significant benefit from rational design and engineering of Fe-N-C SACs,thus offering great opportunities for fabrication of efficient energy conversion and storage devices.