Fe/N co-doped hierarchically porous carbon on N-doped carbon nanotubes towards oxygen reduction reaction

Rational design of efficient and durable non-noble transition metal doped carbon-based oxygen reduction electrocatalysts is the key to reduce catalyst cost and optimize fuel cell performance. Herein, hierarchically porous Fe/N co-doped porous carbon on N doped carbon nanotubes (Fe/N-C@NCNTs) are prepared via the pyrolysis of Fe-doped ZIF-8 embedded on polypyrrole nanotubes (PNTs). The as-prepared Fe/N-C@NCNTs electrocatalyst exhibits the limit current density of 5.7 mA cm-2 and the half-wave potential of 0.84 V (vs. RHE), indicating the excellent oxygen reduction performance. Furthermore, the electrocatalytic activity of Fe/N-C@NCNTs is only reduced by 7% after 650 min of the stability test. The remarkable oxygen reduction performance is attributed to the synergistic effects of abundant Fe-Nx-C active sites, high graphitization degree and hierarchically porous structure of electrocatalyst. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.