Three-dimensional layered Fe-N/C catalysts built by electrospinning and the comparison of different active species on oxygen reduction reaction performance

Abstract

Fe-N/C catalyst is the most promising non-noble-metal catalyst to replace Pt/C, and has long been a material of interest to researchers. It is generally acknowledged that the morphology of carbon support exerts a significant effect on the performance of Fe-N/C catalyst. In this study, the Fe-N/C catalyst that retains the original three-dimensional (3D) structure after calcination was constructed by adding graphene oxide (GO) into the precursor solution by electrostatic spinning technology. The 3D structure is composed of more than 20 layers of interconnected carbon nanofiber networks with carbon nanofiber connections between layers. The dual pore distribution is formed after calcination, comprising macropores between layers and the rich mesopores (3.8 nm) in the nanofibers. Fe-N/C catalysts containing a single active substance of FexN-based, Fe3O4-based, and Fe3C-based material were prepared by adjusting the heat-treatment conditions. The FexN-based Fe-N/C catalyst exhibits the best oxygen reduction reaction (ORR) performance and is superior to commercially available 20 wt% Pt/C catalyst.