Doping oxygen triggered electrocatalytic activity of carbon interpenetrating networks in acid electrolyte

The Fe-N-C catalysts may be promising candidates for replacing platinum group metal (PGM) catalysts to solve sluggish oxygen reduction reaction (ORR) kinetics in the proton exchange membrane fuel cells. However, the activity of Fe-N-C catalysts still has a certain gap compared with commercial Pt/C. Here, we provide a way to increase the intrinsic ac-tivity of Fe-N-C catalysts by designing active sites like ketone functional groups. A self-supporting interpenetrating network catalyst, composed of carbon nanotube (CNT) and carbon nanoparticle (CNP), is synthesized via multiple carbon sources (zinc-zeolitic imi-dazolate frameworks, polyaniline). The interpenetrating network features abundant ke-tone functional groups. The density functional theory (DFT) results prove that ketone groups can promote the ORR activity of FeN4 active sites. This offers a new idea for improving the activity of Fe-N-C catalysts co-doped by oxygen and nitrogen in acidic systems.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

Fe-N-C catalysts are promising candidates to replace platinum group metal catalysts in proton exchange membrane fuel cells. However, their activity still lags behind commercial Pt/C catalysts. In this study, we propose a method to enhance the intrinsic activity of Fe-N-C catalysts by introducing active sites with ketone functional groups. A self-supporting interpenetrating network catalyst composed of carbon nanotubes and carbon nanoparticles is synthesized, which features abundant ketone functional groups. Density functional theory results confirm that ketone groups can enhance the oxygen reduction reaction activity of FeN4 active sites. This offers a new approach to improve the activity of Fe-N-C catalysts co-doped with oxygen and nitrogen in acidic systems.