Iron-Nitrogen Co-doped Carbon with a Tunable Composition as Efficient Electrocatalysts for Oxygen Reduction

Understanding the relationship between composition and activity is essential for the rational design of metal-nitrogen-Carbon (M-N-C) electrocatalysts for the oxygen reduction reaction (ORR). Here, a series of Fe-N co-doped porous carbon (Fe-N-C) electrocatalysts are successfully prepared through the pyrolysis of ZIF-8 doped with different amount of hemin. The catalyst (Fe-55-N-C) exhibits impressive ORR performance with an onset potential (E-onset) of 1.02 V (vs. RHE) and a half-wave potential (E-1/2) of 0.892 V in alkaline media, outperforming commercial Pt/C. Meanwhile, the average kinetic current density (J(k)) of Fe-55-N-C at 0.850 V is 17.5 mA cm(-2), which is 3.3-fold higher than that of commercial Pt/C. Besides, it also delivers anti-methanol poisoning ability and high durability. The high performance stems from the hierarchical porous structure, large specific surface area, and high dispersion of Fe-N-x active sites in Fe-55-N-C. These findings could inspire new perspectives for rationally designing and synthesizing economical and practical non-precious-metal oxygen reduction electrocatalysts.

Automated summary

In this study, a series of Fe-N co-doped porous carbon electrocatalysts were successfully prepared through the pyrolysis of ZIF-8 doped with different amounts of hemin. The Fe-55-N-C catalyst showed impressive ORR performance, outperforming commercial Pt/C. It also exhibited anti-methanol poisoning ability and high durability, thanks to its hierarchical porous structure and high dispersion of Fe-N-x active sites.