Flower‐like FeS Coated with Heteroatom (S,N)‐Doped Carbon as Highly Active and Durable Oxygen Reduction Electrocatalysts

Abstract

AbstractDeveloping viable substitutes for noble metal electrocatalysts is an important activity, since it enables the movement to a cleaner energy future. Few FeS‐based catalysts have been reported as an oxygen reduction reaction (ORR) catalyst in the past and it does not have the combination of stability, conductivity and reactivity that makes it a viable option. Here, flower‐like FeS covered by ultrathin S,N co‐doped carbon layer (FeS@C) displays outstanding electrocatalytic ORR performance in alkaline media. The optimum FeS@C‐800 sample outperforms undoped commercial FeS and standard Pt/C catalysts with a high positive half‐wave potential (E1/2=0.80 V vs. RHE), high limiting current density (6.4 mA cm−2), complete 4‐electron reduction, superior tolerance to methanol and excellent durability towards ORR. The S,N co‐doped carbon layers could not only enhance the conductivity and durability, but also further contribute to the improvement of ORR activity through synergistic effect with FeS. The FeS@C also promotes performance as the air cathode in a Zn‐air battery, which exhibits higher power density than Pt/C. Hence the reported catalyst holds prospects for use as a high performance electrocatalyst for ORR.