Post Iron Decoration of Mesoporous Nitrogen-Doped Carbon Spheres for Efficient Electrochemical Oxygen Reduction

5 years ago

Post Iron Decoration of Mesoporous Nitrogen-Doped Carbon Spheres for Efficient Electrochemical Oxygen Reduction

Yunfeng Lu, Xianyang Li, Hao Bin Wu, Tongtong Shang, Gen Chen, Fei Sun, Zhuang Liu, Jing Liu, Zaiyuan Le, Lin Gu

Iron–nitrogen–carbon (Fe–N–C) catalysts are considered as the most promising nonprecious metal catalysts for oxygen reduction reactions (ORRs). Their synthesis generally involves complex pyrolysis reactions at high temperature, making it difficult to optimize their composition, pore structure, and active sites. This study reports a simple synthesis strategy by reacting preformed nitrogen-doped carbon scaffolds with iron pentacarbonyl, a liquid precursor that can effectively form active sites with the nitrogen sites, enabling more effective control of the catalyst. The resultant catalyst possesses a well-defined mesoporous structure, a high surface area, and optimized active sites. The catalysts exhibit high ORR activity comparable to that of Pt/C catalyst (40% Pt loading) in alkaline media, with excellent stability and methanol tolerance. The synthetic strategy can be extended to synthesize other metal–N–C catalysts. A novel fabrication strategy for metal–N–C electrocatalysts based on the post metal decoration of mesoporous nitrogen spheres is developed. Such synthetic method enables the simple formation of iron-containing active sites on preformed nitrogen-doped carbon host. The good oxygen reduction reaction performance of the prepared Iron/nitrogen-doped mesoporous carbon catalyst is attributed to the synergistic effect between Fe–Nx sites and surface-oxidized Fe nanoparticles.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/aenm.201701154