Improving the Catalytic Performance of Co/N/C Catalyst for Oxygen Reduction Reaction by Alloying with Fe

Abstract

Transition metal and nitrogen co-doped carbon-based nanomaterial has been used as non-precious metal catalyst for oxygen reduction reaction (ORR). In this work, bamboo-like carbon nanotubes structured FeCo/N/C electrocatalyst is proved to show much enhanced performance compared with Co/N/C. MIL-53 (Fe) is used as iron source, MIL-53 (Co) is used as cobalt source and ZIF-8 as carbon source. The ball-milling procedure plays a significant role for the distribution of Fe and Co component and the formation of carbon nanotubes, which is believed to enhance the catalytic performance due to abundant electrocatalytic active sites and efficient mass transfer. The as prepared sample obtained by optimized preparation conditions exhibits outstanding ORR activity in acid solution with an onset potential of 0.96 V vs RHE (reversible hydrogen electrode), half-wave potential of 0.78 V, and a current density of 0.575 m A cm−2 at 0.7 V in a H2-O2 fuel cell test, which provides an ideal viewpoint to develop highly efficient catalyst for the oxygen reduction reaction. The high ORR performance could be attributed to the synergistic effect between Fe and Co and the high conductivity and mass transfer of the carbon nanotube.