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

Abstract

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 activity 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 imidazolate frameworks, polyaniline). The interpenetrating network features abundant ketone 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.