Effective Oxygen Reduction Reaction Performance of FeCo Alloys In Situ Anchored on Nitrogen-Doped Carbon by the Microwave-Assistant Carbon Bath Method and Subsequent Plasma Etching.

Mincong Liu,Xueyan Xue,Haihai Fu,Lili Zhang,Xuhong Guo,Gang Wang,Shengchao Yang,Cunhua Ma,Huifang Yuan,Feng Yu

doi:10.3390/nano9091284

Abstract

Electrocatalysts with strong stability and high electrocatalytic activity have received increasing interest for oxygen reduction reactions (ORRs) in the cathodes of energy storage and conversion devices, such as fuel cells and metal-air batteries. However, there are still several bottleneck problems concerning stability, efficiency, and cost, which prevent the development of ORR catalysts. Herein, we prepared bimetal FeCo alloy nanoparticles wrapped in Nitrogen (N)-doped graphitic carbon, using Co-Fe Prussian blue analogs (Co3[Fe(CN)6]2, Co-Fe PBA) by the microwave-assisted carbon bath method (MW-CBM) as a precursor, followed by dielectric barrier discharge (DBD) plasma treatment. This novel preparation strategy not only possessed a fast synthesis rate by MW-CBM, but also caused an increase in defect sites by DBD plasma treatment. It is believed that the co-existence of Fe/Co-N sites, rich active sites, core-shell structure, and FeCo alloys could jointly enhance the catalytic activity of ORRs. The obtained catalyst exhibited a positive half-wave potential of 0.88 V vs. reversible hydrogen electrode (RHE) and an onset potential of 0.95 V vs. RHE for ORRs. The catalyst showed a higher selectivity and long-term stability than Pt/C towards ORR in alkaline media.

Highlights

Fuel cells and rechargeable zinc-air batteries are the most promising clean auto power for the generation due to their low cost and high energy density [1,2,3,4]
It is already widely known that the oxygen reduction reaction (ORR) is a slow kinetic process in cathodic reactions [5,6]
Wen et al [20] reported FeCo alloy nanoparticles embedded in Nitrogen (N)-doped carbon with excellent ORR performance, which was attributed to the core-shell nanostructure, the large specific surface area, and the synergetic effect of the mutual element for FeCo alloy nanoparticles wrapped with N-doped carbon (FeCo@NC)

Summary

Introduction

Fuel cells and rechargeable zinc-air batteries are the most promising clean auto power for the generation due to their low cost and high energy density [1,2,3,4]. Wen et al [20] reported FeCo alloy nanoparticles embedded in Nitrogen (N)-doped carbon with excellent ORR performance, which was attributed to the core-shell nanostructure, the large specific surface area, and the synergetic effect of the mutual element for FeCo@NC. All the previous research showed that the catalysts with bimetallic active sites exhibited optimal performance with large surface areas, porous nanostructures, and rich active centers. The as-prepared DBD-FeCo@NC exhibited good electrochemical ORR performance, e.g., a positive half-wave potential of 0.88 V vs RHE and an onset potential of 0.95 V vs RHE. We believe that this strategy provides potential for the preparation of similar superstructures of other effective catalysts with much active sites

Synthesis of Samples

Characterizations

ORR Text

Findings

Preparation Method Preparation