A novel metal organic framework-derived carbon-based catalyst for oxygen reduction reaction in a microbial fuel cell

To improve the power generation of microbial fuel cell (MFC), the cathode is modified to increase its oxygen reduction reaction (ORR) activity by using a Cu, N-incorporated carbon-based material as catalyst, which obtained from pyrolyzing ORR active Cu (II)-based metal organic framework (MOF; Cu-bipy-BTC, bipy = 2,2'-bipyridine, BTC = 1,3,5-tricarboxylate). MOF-800 (the product of pyrolyzing Cu-bipy-BTC at 800 degrees C) shows porous structure with micropores ranging from 0.5 to 1.3 nm and mesopores ranging from 27 to 46 nm. It also exhibits improved ORR electrocatalytic activity with a higher current density of -3.06 mA cm(-2) compared to Cu-bipy-BTC. Moreover, the charge transfer resistance of MOF-800 cathode (1.38 Omega) is much smaller than that of Cu-bipy-BTC cathode (176.8 Omega). A maximum power density of 326 +/- 11 mW m(-2) is achieved by MOF-800-MFC, which is 2.6 times of that of Cu-bipy-BTC-MFC and comparable with Pt/C-MFC (402 +/- 17 mW m(-2)). The results imply the enhancements of ORR catalytic activity and electrical conductivity of MOF-800 are due to the enhanced porous structure and abundant active sites (C-N, Cu-N-x), which result in the improved power generation of MFC. This study provides technical and theoretical validation for the MFC performance improvement by ORR active MOF-derived catalysts modified cathodes.