Description:
The requirement of sustainable energy is of great significance for easing the energy shortage crisis, in which the oxygen reduction reaction (ORR) in metal-air batteries and fuel cells plays a crucial role in efficient energy conversion. The development of noble-metal-free, efficient, and stable ORR electrocatalysts is highly desirable but remains a significant challenge. Herein, we report an atomically dispersed Fe and N co-doped hierarchically porous carbon (Fe-SA/HPC) catalyst derived from two-dimensional leaf-like ZIF-L with preeminent ORR activity. The Fe-SA/HPC catalyst, benefitting from hierarchically porous structure and rich highly-dispersed active sites of FeN x , put up ORR performance with a half-wave potential (E 1/2 ) of 0.91 V vs. the reversible hydrogen electrode (RHE) in 0.1M KOH electrolyte. The current density with a 0.382 mg cm −2 loading of catalyst in a rotating disk electrode (RDE) test can reach 24.65 mA cm −2 at 0.8 V, which is nearly twice that of commercial 20 wt% Pt/C. Density functional theory calculations demonstrate that the co-regulation of defects and graphitic nitrogen can optimize the local electronic redistribution for active sites and endow them with a lower free-energy barrier towards ORR. This work provides certain inspiration for the development of highly reactive atomic metal catalysts through rational topology structure engineering and nitrogen moiety regulation