Coal tar pitch–derived hierarchically porous Fe–N co-doped graphene as an electrocatalyst for oxygen reduction reaction.

Fe-N-C catalysts are highly competitive alternatives to noble-metal catalysts for the oxygen reduction reaction (ORR). Herein, an efficient Fe and N co-doped three-dimensional graphene (Fe-N-G) catalyst that possesses a hierarchical porous structure was synthesized using a facile strategy. The Fe-N-G catalyst was prepared using a template method, in which coal tar pitch was used as the carbon source, aspartic acid as the nitrogen source, and CaCO 3 serves as the template. The resulting catalyst features a three-dimensional hierarchical porous structure with abundant channels, facilitating mass transfer and enhancing accessibility of Fe-N X active sites. The Fe-N-G2 catalyst exhibits an outstanding half-wave potential (0.848 V vs. RHE), surpassing that of commercial 20 wt% Pt/C (0.841 V vs. RHE), and demonstrates excellent long-term durability in alkaline electrolyte. This study offers a novel strategy for developing an efficient and low-cost Fe-N-C catalyst for ORR. • Fe-N-G#2 with 3D hierarchical porous structure has been synthesized via pyrolysis. • Fe-N-G#2 exhibits a high specific surface area, abundant structural defects, and enriched Fe-N 4 active sites. • The 3D hierarchical porous graphene structure facilitates mass transfer, which enhances the catalytic performance for ORR. • Fe-N-G#2 exhibits outstanding ORR activity and durability compared with 20 wt% Pt/C.