FeCo Bimetallic Alloy Nanoparticles Embedded in Nitrogen-Doped Porous Carbon for Effective Oxygen Reduction in Zinc-Air Batteries

The rational design and simple preparation of non-noble metal catalysts for the oxygen reduction reaction (ORR) are urgently needed for mass commercial full-cell applications, but many challenges still exist. Herein, FeCo bimetallic alloy nanoparticles in nitrogen-doped dodecahedral porous carbon (FeCo-NC) with a controllable microstructure and catalytic efficiency are prepared by the secondary carbonization method using ZIF-67 as the self-sacrificial template and pore former and FeCl3 as the activated metal source. By adjusting the amount of FeCl36H(2)O to 60 mg, the prepared catalyst (FeCo-NC-60) exhibits an optimal configuration characterized by a multilayered porous structure, a significant specific surface area, and a substantial abundance of active centers (pyridinic nitrogen, graphitic nitrogen, and Fe-N-x). Therefore, the FeCo-NC-60 catalyst has an excellent catalytic effect in 0.1 M KOH, and its half-wave potential is as high as 0.874 V, which exceeds that of commercial Pt/C by about 20 mV. Furthermore, a zinc-air battery that was created using FeCo-NC-60 as the air cathode demonstrates notable characteristics such as a substantial open-circuit voltage of 1.473 V, an impressive specific capacity of 703 mA h g(-1) at 10 mA cm(-2), and exceptional reversible porperties and stability. This synthesis method takes into account the ORR catalytic activity and enhances the stabilization of the fabricated catalysts. It offers a strategy for accomplishing bimetal doping and enhancing the active sites of M-N-x (M = Fe, Co).

Automated summary

This paper presents a rational and simple method for preparing FeCo bimetallic alloy nanoparticles on nitrogen-doped dodecahedral porous carbon. The synthesized catalyst exhibits a multilayered porous structure, a high specific surface area, and an abundance of active centers, resulting in excellent catalytic activity for the oxygen reduction reaction. The catalyst also demonstrates notable performance as an air cathode in a zinc-air battery, with high open-circuit voltage, specific capacity, and stability.