UiO66-NH2 as self-sacrificing template for Fe/N-doped hierarchically porous carbon with high electrochemical performance for oxygen reduction in microbial fuel cells

• DOI: 10.1016/j.electacta.2019.134777
• Publication Date: 2019-08-30T20:58:23Z
• Authors: Kengqiang Zhong; Xun Lu; Yi Dai; Shaoran Yang; Jieyi Li; Hongguo Zhang; Yan Wang; Jianliang Zuo; Jinfeng Tang; Minhua Su
• Keywords: Methanol fuel; Carbon fibers

Abstract Rational design and assembly of catalyst skeleton incorporated with active dopants is an effective approach to explore superior electrocatalyst for oxygen reduction reaction (ORR) in the microbial fuel cells (MFCs). Herein, we fabricate an efficient electrocatalyst based on hierarchically porous carbon doped with highly active iron (Fe) porphyrins compound using UiO66-NH2 as template which plays dual-functional roles of self-sacrificing template and nitrogen source. The well-organized micro/meso-porous system of Fe/N-doped hierarchically porous carbon provides various porous channels for electron transfer and shortens the mass transport process, which is in favor of ORR. The resultant Fe-PP-UiO66-1/3 exhibits remarkable ORR performance with high onset potential (0.397 V), half-wave potential (−0.011 vs. Ag/AgCl) under neutral condition, outpacing the commercial Pt/C catalyst. In addition, under alkaline condition, Fe-PP-UiO66-1/3 displays four-electron pathway, excellent methanol and long-term durability. The MFC with Fe-PP-UiO66-1/3 cathode shows a maximum power density of 1607.2 mW m−3, and outperforms the MFC with 20 wt% commercial Pt/C catalyst (1428.98 mW m−3). This study paves the way to synthesize cost-effective, superior electrochemical performance, high-conductivity, and non-precious metal-based electrocatalysts for MFCs.