Atomically-dispersed Fe-Nx and C–S–C ordered mesoporous carbons as efficient catalysts for the oxygen reduction reaction in a microbial fuel cell

• Published in: Journal of alloys and compounds 2021-01, Vol.852, p.156994, Article 156994
• Main Authors: Han, Wuli, Li, Chuanhua, Jiang, Yu, Ma, Zhaofei, Zhang, Yan, Yan, Xuemin, Zheng, Xianfeng
• Format: Article
• Language: English
• Subjects: Biochemical fuel cells; Catalysts; Catalytic activity; Dispersion; Electro-catalysis; Fe-Nx and C–S–C; Maximum power density; Mesoporous carbon; Microbial fuel cells; Microorganisms; Morphology; Nitrogen; Open circuit voltage; Oxygen reduction reaction; Oxygen reduction reactions; Porosity
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2020.156994

An efficient catalyst (Fe/S–N/C) possessing abundant ordered mesoporous was synthesized via a facile strategy, in which the active Fe-Nx and C–S–C species exhibited atomic dispersion. Attributing to its well-developed porosity, the total pore volume and specific surface area of Fe/S–N/C catalyst reach 0.556 cm3 g−1 and 980.9 m2 g−1 respectively. Electron microscopy results reveal the uniform dispersion of atomic Fe-Nx and C–S–C in this catalyst, which has inherited a polyhedral morphology derived from ZIF-8. X-ray spectroscopy measurements further validate that the Fe/S–N/C composite can provide abundant and highly efficient active sites for ORR. The atomic ratio of nitrogen is 4.28%, with high relative concentrations of the active pyridinic N and Fe-Nx. Furthermore, the Fe/S–N/C catalysts demonstrate significant ORR activity in the practical application of MFC devices. Based on a high open circuit potential (0.674 V) and maximum power density (1436.42 mW m−2) of the MFC device which uses the Fe/S–N/C as air-cathode catalyst, the Fe/S–N/C displays better catalytic activity than commercial 20% Pt/C catalyst. This investigation provides a new strategy to design an effective, low-cost ORR catalyst for MFC devices. •The mesoporous carbons with Fe-Nx and C–S–C active sites (Fe/S–N/Cs) were successfully synthesized via a facile strategy.•The Fe/S–N/C catalysts exhibit large specific surface areas (980.9 m2 g−1) and high pore volumes (0.556 cm3 g−1).•MFC devices with the Fe/S–N/Cs catalysts exhibit higher maximum power density (1436.42 mW m−2) than that of commercial Pt/C.