Anti-perovskite metal carbides: A new family of promising electrocatalysts for oxygen reduction in alkaline solution

Abstract

In this paper, the effect of Zn incorporation into the lattice of Fe3C, CoCx and Ni3C is investigated. It is discovered that the oxygen reduction reaction (ORR) of Fe3C, CoCx and Ni3C can be enhanced through Zn incorporation into their lattices. This results in the formation of Co3ZnC, Fe3ZnC and Ni3ZnC electrocatalysts. The catalysts show appreciable ORR performances in O2-saturated 0.1 M KOH, with Fe3ZnC and Co3ZnC exhibit the most positive onset potential (0.92 V) and half-wave potential (0.8 V). The Fe3ZnC electrocatalyst exhibits the highest current density (5.3 mA cm−2) at low electrode potential (0.2−0.6 V); comparable to that of commercial Pt/C. Both Fe3ZnC and Co3ZnC show activity retention of 99.9 % for ∼15 h, and offer good methanol tolerance. It indicates their superior performance. This work shows a rather interesting and rather simple chemical strategy to enhance the ORR activity of binary metal carbides for fuel applications.