Highly dispersed cobalt-nitrogen co-doped carbon nanofiber as oxygen reduction reaction catalyst

Abstract

Transition metal-nitrogen doped carbon-based catalysts have become promising alternatives to precious metal catalysts for the oxygen reduction reaction (ORR). Here, we report a nitrogen-doped carbon nanofiber electrocatalyst coordinated with highly dispersed cobalt atoms (Co-N/C) with a high specific surface area prepared by an electrospinning method. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM) results confirmed that Co was highly dispersed within the prepared Co-N/C catalyst. X-ray photoelectron spectroscopy for N 1s spectra showed that the N species mainly existed in the forms of pyridinic N and graphitic N. This Co-N/C catalyst exhibited considerable ORR performance with onset and half-wave potentials at 0.92 and 0.80 V (relative to the reversible hydrogen electrode (RHE)), which are comparable to those of commercial Pt/C. With the prepared Co-N/C catalyst as the cathode, a Zn-air battery displayed an open-circuit potential of 1.54 V and a peak power density of 190 mW·cm−2 at 25 °C, which suggest a promising application.