Fe7C3–Fe3N/FeNxCy Decorated Carbon Material as Highly Efficient Catalyst for Oxygen Reduction Reaction in Al-Air Batteries

Abstract

Traditionally, oxygen reduction reactions (ORR) are catalyzed by Pt/C, which is expensive but essentially efficient catalyst. So doping of highly active moieties onto carbon supports could be investigated as a practical and inexpensive strategy for catalysis of ORR. The present study reported noncrystalline FeNxCy species, crystalline Fe7C3 and Fe3N nanoparticles co-decorated ketjenblack (KB) carbon catalyst (denoted as Fe–N–KB–HCl) for ORR prepared using ferrous sulfate, melamine and KB as raw materials. Carbon nanotubes (CNT) were observed in the catalyst, which caused to a high specific surface area (1125 m2g–1) of the catalyst. The Fe–N–KB–HCl catalyst fabricated in this study exhibited a catalytic performance similar to that of commercial 20% Pt/C for ORR in alkaline solution. Moreover, it exhibited a higher voltage (1.51 V) at a discharge density of 50 mA cm–2 in an in-house made Al-air battery than that of the commercial 20% Pt/C catalyst (1.45 V). So the Fe–N–KB–HCl catalyst prepared in this study could be used for developing inexpensive but highly efficient catalysts for catalysis of ORR and have potential to be used for commercial purposes.