Synthesis of Non‐precious N‐doped Mesoporous Fe₃O₄/CoO@NC Materials towards Efficient Oxygen Reduction Reaction for Microbial Fuel Cells

Abstract

N-doped transition metal oxides are strategic materials towards the efficient oxygen reduction reaction (ORR) of microbial fuel cells (MFCs). Non-precious Ndoped Fe 3 O 4 /CoO@NCÀ T (T represents carbonization temperature) catalysts are prepared by an efficient twostep strategy for ORR. Fe 3 O 4 /CoO@NC-750 exhibits the best performance with an efficient four-electron transfer pathway. The optimal power density of MFCs by using Fe 3 O 4 /CoO@NC-750 as the cathode catalyst (1243.4 mW • m À 2 ) is superior to that of the MFCs with commercial Pt/C catalyst (1080 mW • m À 2 ), which shows an outstanding activity towards ORR. No significant decrease in output voltage results over 70 days, which shows an excellent electrochemical stability.

Highly active N‐doped non‐precious transition metal Fe@ N–C catalysts for efficient oxygen reduction reaction in microbial fuel cells

“…MFC was made up of single chamber cubic reactor with volume of 28 mL 25 . MFC setup and operation, structural characterization, and electrochemical characterization are described in detail in supporting materials.…”

“…22,23 Metal-organic framework (MOF) derivatives are considered as ideal sacrificial templates for preparation Fe-N-C materials because of their large specific surface area, uniform pore distribution, and adjustable chemical structure. 24,25 Zhang et al 26 prepared Fe-N-C catalyst from Fe-doped Zn-ZIF-8, which gave an ORR half-wave potential of 0.81 V vs reversible hydrogen electrode (RHE) in acidic media. Besides Fe-N x , the Fe/Fe 3 C in Fe-N-C catalysis system also plays a role of toward ORR.…”