Promoting interfacial charge transfer by B/N co-doping enables efficient ORR catalysis of carbon-encapsulated Fe2N

Abstract

High efficiency and durability are two key targets for developing electrochemical catalysts for oxygen reduction reaction (ORR). Here, B/N co-doped porous carbon shell-encapsulated Fe₂N nanoparticles (NPs) were synthesized as an active and durable catalyst (Fe₂N@BNC) for ORR. Introduction of the B dopant promotes the doping of the N element, amends the carbon shell, and induces the conversion of pyrrolic nitrogen into C–N–B. This immensely promotes the electron transfer from the encapsulated Fe₂N NPs to the carbon surface, tailors the electronic structure of the carbon shell, and therefore improves the ORR activity of the inert carbon. The optimized electrocatalyst Fe₂N@BNC-2 achieved remarkable activity and durability for ORR, which was even better than that of Com. Pt/C (20 wt% Pt).