关键词: 微生物燃料电池, 金属有机框架, 氮掺杂, 氧还原反应, Fe / N-MC-T催化剂.

Abstract: The development of non-noble metal oxygen reduction catalysts (ORR) to improve microbial fuel cell (MFC) performance remains extremely challenging. Herein, nitrogen-doped iron-based porous carbon nanotube Fe/N-MC-T ORR catalysts were derived from Fe/N-MOF by pyrolyzation using acetonitrile as the nitrogen precursor in a low-cost organic solvent. The Fe/N-MC-T catalysts with different pyrolysis temperatures (T) were characterized by SEM, TEM, BET, XRD and XPS. Fe/N-MOF showed a smooth rice-like structure with a particle size of about 400×50 nm. The Fe species in Fe/N-MC-T mainly exists in the form of zero-valent iron with small amount of Fe3C. The electrochemical tests reveal that the onset and half-wave potentials of Fe/N-MC-T were 0.89 V and 0.80 V respectively, which are slightly lower than those of the commercial Pt/C (0.92 V and 0.82 V), indicating that Fe/N-MC-700 had the high electrocatalytic activity for ORR. The MFC with Fe/N@MC-700 showed the highest power density of 864.1 mW?m-2, which was about 2.25 times as compared to that of MFC with carbon cloth, and slightly lower than that of MFC with Pt/C (20 wt%) (1002.0 mW?m-2), demonstrating the Fe particles wrapped in carbon nanotubes are highly active to ORR.

Key words: microbial fuel cells, metal organic framework, nitrogen doping, oxygen reduction reaction, Fe/N-MC-T catalyst.