Bimetallic zeolitic imidazole framework derived Co@NC materials as oxygen reduction reaction catalysts application for microbial fuel cells

摘要

Microbial fuel cells (MFCs), a promising future energy conversion technology, play a sig-nificant role in the area of sustainable and renewable energy. In air-cathode MFCs, the catalytic activity for oxygen reduction reaction (ORR) of cathode electrocatalyst is the key factor to the performance of MFCs. Development of efficient and economical ORR elec-trocatalysts is an important step for the wide application of MFCs. Herein, Co wrapped carbon nanotubes (CNTs) N-doped nanoporous carbon materials (Co@NC-CoxZny) are constructed via a facile zinc-assisted growth pyrolytic approach of bimetallic zeolitic imidazole frameworks (BMZIFs)-derived strategy. They are directly prepared via carbon-ization of the precursor CoxZny-BMZIFs. During the pyrolysis process, the evaporation of zinc plays critical role in the in-situ growth of CNTs. For instance, the optimal catalyst, Co@NC-Co1Zn3, exhibits excellent ORR performance activity and stability with on-set po-tential (Eon-set) of 0.830 V (vs. RHE) and diffusion-limited current density (jL) of 6.706 mA cm(-2), which is superior to the benchmark catalyst of commercial 20 wt Pt/C. Additionally, Co@NC-Co1Zn3 displays four-electron pathway, long-term stability and better resistance to methanol tolerance. The MFC with Co@NC-Co1Zn3 cathode shows a maximum power density of 1039 mW m(-2), and outperforms the MFC with commercial 20 wt Pt/C catalyst (678 mW m(-2)). This work paved the way for exploring cost-effective, superior performance non-precious metal-based catalysts for air-cathode MFCs. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.