Synergistic Binary Fe-Co Nanocluster Supported on Defective Tungsten Oxide as Efficient Oxygen Reduction Electrocatalyst in Zinc-Air Battery.

Abstract

Rational design of metal oxide supported non‐precious metals is essential for the development of stable and high‐efficiency oxygen reduction reaction (ORR) electrocatalysts. Here, an efficient ORR catalyst consisting of binary Fe/Co nanoclusters supported by defective tungsten oxide and embedded N‐doped carbon layer (NC) with a 3D ordered macroporous architecture (3DOM Fe/Co@NC‐WO2− x ) is developed. The oxygen deficient 3DOM WO2− x not only serves as a porous and stable support, but also enhances the conductivity and ensures good dispersion of the binary Fe/Co nanocluster, benefiting its ORR catalytic activity. Theoretical calculation shows that there exists a synergistic effect of electron transfer from Fe to Co in the supported binary Fe/Co cluster, promoting the ORR reaction energetics. Accordingly, the 3DOM Fe/Co@NC‐WO2− x catalyst exhibits excellent ORR activity in alkaline medium with a half wave potential (E 1/2) of 0.87 V higher than that of Pt/C (0.85 V). The zinc–air batteries assembled by 3DOM Fe/Co@NC‐WO2− x cathode deliver a higher power density and specific capacity than that of Pt/C. A new strategy of combining synergistic binary‐metal nanoclusters and conductive metal oxide support design is provided here to develop efficient and durable ORR electrocatalyst.