In situ Fe2N@N-doped porous carbon hybrids as superior catalysts for oxygen reduction reaction.

Abstract

Developing efficient and economical noble-metal free catalysts for oxygen reduction reaction (ORR) is one of the essential factors for the industrialization of fuel cells. Recent studies on transition metal ORR catalysts have become the priority to practical low-temperature fuel cells. Herein, we proposed a novel in situ design, Fe2N nanoparticles (NPs) in an N doped porous carbon matrix (Fe2N@NPC) derived from metal organic frameworks (MOFs) as high-performance ORR catalysts. The decorated Fe2N NPs increase the amount of Fe-N/C bonding as catalytic site. Meanwhile, the coated NPC facilitates the mass transport of the reaction and improves the conductivity simultaneously. The catalyst exhibits an onset potential of -0.038 V, a half-wave potential of -0.175 V in 0.1 M KOH, and superior stabilities and methanol tolerance performances to commercial Pt/C catalysts. More importantly, the proposed in situ 'two-step' annealing route provides potential possibilities for producing other non-precious metal catalysts for ORR.