Nitrogen-doped porous carbon fiber with enriched Fe2N sites: Synthesis and application as efficient electrocatalyst for oxygen reduction reaction in microbial fuel cells

• Published in: Journal of colloid and interface science 2022-06, Vol.616, p.539-547
• Main Authors: Lu, Hao, Jiang, Ying, Xiao, Gang, Hu, Jiadong, Yang, Lu, He, Xiu, Xiang, Xuemei, Li, Min, Sun, Wei, Lu, Zhisong, Zhu, Zhihong, Qiao, Yan
• Format: Article
• Language: English
• Subjects: Fe[sbnd]N[sbnd]C catalysts; Metal organic framework; Microbial fuel cells; N-doped porous carbon fiber; Oxygen reduction reaction
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2022.02.106

[Display omitted] •A porous carbon fiber with abundant Fe2N sites (Fe2N/NPCF) was developed as high performance ORR catalyst for MFCs.•In situ pyrolysis under NH3 atmosphere of MIL-53(Fe) in electrospun fibers is critical for the construction of Fe2N sites.•The synergetic effect of abundant Fe2N and hierarchical porous structure with pyrrolic nitrogen endues Fe2N/NPCF superior catalytic performance to commercial Pt/C.•The Fe2N/NPCF catalyst exhibits higher maximum power density and better long term stability than that of commercial Pt/C in single chamber MFC. Low-cost, stable and highly efficient oxygen reduction reactions (ORR) electrocatalysts are of great significance for microbial fuel cells to break the limit of the air cathode. The expensive noble metal catalysts are easy to be contaminated due to biofouling, which could damage the catalytic activity significantly. Among the reported non-noble metal catalysts, FeCN materials are promising substitutes that have comparable catalytic activity with Pt/C. In this article, a facile process to obtain N-doped porous carbon fibers (NPCF) with abundant Fe2N moieties from iron based metal organic framework (MOF(Fe)) embedded electrospun fibers has been developed. The fiber structure promotes the in situ conversion of Fe2N sites in embedded MOF(Fe) during pyrolysis under NH3 atmosphere. The abundant Fe2N sites, presence of pyrrolic nitrogen and hierarchical porous structure of obtained Fe2N/NPCF make it possess excellent electrocatalytic activity to ORR with comparable performance (E1/2 = 0.8648 V) and superior long term stability to commercial 20 wt% Pt/C. This work expends the toolbox for design of high performance cathodic catalysts for MFCs and also provides original insights in Fe-N active sites construction for FeNC ORR catalysts.