Atomically Dispersed Fe on Nanosheet-linked, Defect-rich, Highly N-Doped 3D Porous Carbon for Efficient Oxygen Reduction

Abstract

Exploring cost-effective and high-performance oxygen reduction reaction(ORR) electrocatalysts to replace precious platinum-based materials is crucial for developing electrochemical energy conversion devices but remains a great challenge. Herein, Fe single atoms anchored on nanosheet-linked, defect-rich, highly N-doped 3D porous carbon(Fe-SAs/NLPC) electrocatalysts were obtained by pyrolyzing salt-sealed Fe-doped zeolitic imidazolate frameworks(ZIFs). NaCl functions both as pore-forming agent and closed nanoreactor, which can not only lead to the formation of defects-rich three-dimensional interconnected structures with high N-doping content to expose abundant active sites, promote mass transfer and electron transfer, but also facilitate the effective incorporation of Fe to form Fe-Nx active sites without aggregation. These unique characteristics render Fe-SAs/NLPC outstanding electrocatalytic activity for ORR, with one-set potential of 0.96 V and high kinetic current density(jK) of 33.32 mA/cm2 in alkaline medium, which surpass the values of most nonprecious-metal catalysts and even commercial Pt/C.