PBA@PPy derived N-doped mesoporous carbon nanocages embedded with FeCo alloy nanoparticles for enhanced performance of oxygen reduction reaction

Abstract

Due to the obstacle of sluggish kinetics on cathode of fuel cells and metal–air batteries, developing low-cost and durable electrocatalysts to replace the platinum-based catalysts still remains a grand challenge. Here, we describe a simple self-template approach to synthesize N-doped mesoporous carbon nanocages (FeCo@NC) embedded with FeCo alloy nanoparticles as oxygen reduction reaction (ORR) electrocatalyst. The resulting heterostructure is derived from corresponding PBA@PPy composites, which are pre-prepared by polymerization of polypyrrole (PPy) layer on Prussian blue analogue (PBA) nanocubes. The FeCo alloy nanoparticles with an average particle size of ∼10 nm are well dispersed and confined within the shell of carbon nanocages. Benefiting from the mesoporous structure and the synergetic interaction of binary metals, the optimized FeCo@NC-3-800 electrocatalyst exhibits comparable ORR performances (0.83 V for half-wave potential (E1/2), 5.323 mA cm−2 for limiting current density (Jk)), superior durability and excellent methanol tolerance to the commercial Pt/C (20 wt%). This work provides an appropriate strategy for general, efficient and practical synthesis of more promising non-precious metal electrocatalyst with high ORR activity.