Dual-Atom Fe(Ii,Iii)N2(Μ2-N)2cu(I,Ii)N Moieties Anchored on Porous N-Doped Carbon Driving High-Efficiency Oxygen Reduction Reaction

Atomically distributed iron electrocatalyst is valid for oxygen reduction reaction (ORR). However, accurate regulation of the structure improving its intrinsic activity is a challenge. Herein, a dual-atom catalyst FeCu-NC with atomically distributed Fe and Cu co-anchored on porous N-doped carbon is obtained. The FeN4 and CuN3 couple sites bridged by two nitrogen atoms, exist as Fe(II,III)N2(µ2-N)2Cu(I,II)N moieties with the metal distance of ~2.5 Å in the structure of FeCu-NC. The synergistic effect of Fe and Cu dual-atom reducing the dissociation energy of *OOH intermediate, allows an optimized 4e- ORR reaction pathway. The FeCu-NC exhibits high-efficiency ORR activity with the half-wave potential (E1/2) of 0.889 V (vs RHE) and outstanding stability without obvious decay for the E1/2 after 10,000 cycles. The FeCu-NC based Zn-air battery presents large specific capacity of 788 mAh g-1 and energy density of 990 Wh kg-1 as well as high charge-discharge cycling stability superior to the Pt/C.