Fe3O4@N-Doped Interconnected Hierarchical Porous Carbon and Its 3D Integrated Electrode for Oxygen Reduction in Acidic Media.

Yi Wang,Tongwen Yu,Junwei Chen,Shuqin Song,Kun Wang,Mingmei Wu

doi:10.1002/advs.202000407

Abstract

The rational design of electrode structure with catalysts adequately utilized is of vital importance for future fuel cells. Herein, a novel 3D oriented wholly integrated electrode comprising core–shell Fe3O4@N‐doped‐C (Fe3O4@NC) nanoparticles embedded into N‐doped ordered interconnected hierarchical porous carbon (denoted as Fe3O4@NC/NHPC) is developed for the oxygen reduction reaction (ORR). The as‐prepared catalyst possesses novel structure and efficient active sites. In rotating disk electrode measurements, the Fe3O4@NC/NHPC exhibits almost identical ORR electrocatalytic activity, superior durability, and much better methanol tolerance compared with the commercial Pt/C in acidic media. To the authors’ knowledge, this is among the best non‐precious‐metal ORR catalysts reported so far. Importantly, the Fe3O4@NC/NHPC is successfully in situ assembled onto carbon paper by the electrophoresis method to obtain a well‐designed 3D‐ordered electrode. With improved mass transfer and maximized active sites for ORR, the 3D‐oriented wholly integrated electrode shows superior performance to the one fabricated by the traditional method.

Highlights

Fuel cells are considered as one of the most efficient and clean energy conversion devices to meet the requirements for future energy-demanding systems
Among various non-precious metal catalysts (NPM) catalysts, metal–nitrogen another effective route to improve the performance of M-Nx/C catalyst.[2b,f,3] Since the oriented wholly integrated electrodes (ORR) is a multi-phase reaction involving liquid, gas, and solid phases in fuel cells, a well-designed microstructure could facilitate the ORR catalytic process in multiple ways: 1) providing rapid mass transfer path for ORR-related species (O2, H+, OH−, and H2O); 2) affording sufficient surface area to maximize the exposure of accessible active sites; 3) protecting the catalyst nanoparticles from aggregation or dissolution, enhancing the long-term durability
The fabrication of the Fe3O4@NC/N-doped HP carbon (NHPC) was illustrated in Figure 1a

Summary

Introduction

Fuel cells are considered as one of the most efficient and clean energy conversion devices to meet the requirements for future energy-demanding systems. The ORCID identification number(s) for the author(s) of this article transfer pathways and decreased active sites exposure. Unimpeded ORR catalytic process is critical for improving the KGaA, Weinheim We develop a 3D-oriented wholly integrated electrode by an electrophoresis method to in situ assemble the Fe3O4@NC/NHPC onto carbon paper (CP). The as-prepared electrode outperforms the one fabricated by the traditional method in terms of ORR performance

Results and Discussion

Conclusion

Conflict of Interest