Effect of the Amount of Carbon/Nitrogen Feedstocks on Oxygen Reduction Reaction Activity of FeCoNi Nanoparticles Embedded in Nitrogen‐doped Carbon Matrix

Abstract

Carbonaceous transition metal catalysts have become one of the most promising materials to replace expensive Pt‐based catalysts because of their high oxygen reduction reaction (ORR) activity and stability. In this paper, three metal‐containing nanoparticles, namely FeCoNi, were encapsulated into carbonaceous matrixes by simple stirring and calcination. The morphology of as‐obtained FeCoNi particles was controlled and investigated by adjusting the amount of melamine as carbon (and nitrogen) source. FeCoNi@NC/CNTs‐6 showed the best ORR activity among all of the catalysts. The half‐wave potential of the FeCoNi@NC/CNTs‐6 is 0.83 V vs. RHE, and its limiting current density is up to 5.16 mA cm−2. It was found that the unique 3D carbon‐based matrix may be the main reason for this enhanced ORR activity. Additionally, higher content of pyridine N and Fe(Co/Ni)Nx group in FeCoNi@NC/CNTs‐6 catalyst may be another reason. Finally, FeCoNi@NC/CNTs‐6 was also used as a cathode to assemble the zinc‐air battery. The results showed that it had better battery performance than the reference Pt/C catalyst. These results could provide theoretical and practical support for the enlarged applicability of similar catalysts.