FeCo nanoalloys encapsulated in pod-like N-doped carbon nanotubes as efficient oxygen reduction reaction electrocatalysts for zinc-air batteries

Abstract

The construction of non-noble metal catalysts with high activity and stability is of great importance for boosting oxygen reduction reaction (ORR) process. Herein, a novel catalyst is developed based on FeCo alloy nanoparticles encapsulated by pod-like N-doped carbon nanotubes in situ grown on carbon black (FeCo@PNCNT-CB). The catalysts are synthesized by a simple chemical vapor deposition (CVD) strategy and the pyrolysis temperature plays a critical impact on the ORR features when FeCo@PNCNT-CB is used as ORR electrocatalysts. The optimized electrocatalysts of FeCo@PNCNT-CB-800 displays a half-wave potential of 0.85 V, which is closed to that of Pt/C in alkaline conditions. Meanwhile, FeCo@PNCNT-CB-800 also delivers a superior stability and methanol tolerance, which is much better than that of commercial Pt/C. Importantly, when FeCo@PNCNT-CB-800 is utilized as a cathode for zinc-air batteries, a high open-circuit potential of 1.506 V, remarkable peak power density of 190.6 mW cm−2, and satisfactory stability are achieved.