Porous Fe, Co, and N-co-doped carbon nanofibers as high-efficiency oxygen reduction catalysts

Abstract

Oxygen reduction reaction (ORR) is an important reaction in fuel cells. Designing electrocatalysts with outstanding performance is always the key to renewable-energy technologies for fuel cells. Herein, we demonstrate the Fe, Co, and N co-doped porous carbon nanofibers (FeCo/N-C CNFs) as a novel high-performance electrocatalyst for ORR. The synthesis method of this electrocatalysts material is very simple via high-temperature calcination pyrolysis of zinc, cobalt bimetallic zeolitic imidazolate framework (ZIF)-coated electrospun polyacrylonitrile fibers. In alkaline media, the FeCo/N-C CNFs shows a Pt-like ORR performance. The FeCo/N-C CNFs catalysts exhibit excellent performance with an onset potential of 0.99 V and a half-wave potential of 0.83 V in 0.1 M KOH solution, which is similar to those of 20 wt% Pt/C catalysts. Meanwhile, regarding long-term durability and methanol tolerance, the as-synthesized FeCo/N-C CNF catalysts also outperform commercial Pt/C. The unusual catalytic activity mainly from the improvement of electron transfer channels and catalytic sites arise from Fe, Co, and N doping in the porous structure carbon nanofibers.