Co/Al2O3-rGO nanocomposite as cathode electrocatalyst for superior oxygen reduction in microbial fuel cell applications: The effect of nanocomposite composition

• Published in: Electrochimica acta 2017-11, Vol.254, p.1-13
• Main Authors: Papiya, Farhan, Nandy, Arpita, Mondal, Sudipta, Kundu, Patit Paban
• Format: Article
• Language: English
• Subjects: Cathode catalyst; Cobalt alumina graphene nanocomposite; Microbial fuel cells; Oxygen reduction reaction; Power output
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2017.09.108

[Display omitted] •Co based transition metal nanocatalyst employed as an alternative to noble metal catalyst for oxygen reduction.•Alumina (Al2O3) and reduced graphene (rGO) emerged as the effective catalyst support.•The electrode modified by Co based nanocatalyst exhibited an excellent electro-catalytic activity for oxygen reduction reaction (ORR).•Co80/(Al2O3)10–rGO10 showed better MFC result compared to Pt/C. This study reports the synthesis of non-platinum group metal (non-PGM) catalyst based on low cost cobalt nanoparticles supported by alumina and reduced graphene oxide (Al2O3-rGO) matrix as a new generation alternative to expensive platinum catalyst. 1: 1 Al2O3 and rGO ratio has found to be the most effective support for generating higher energy in single chambered microbial fuel cell (SC-MFC). The crystalline structure, chemical composition and surface structure of the developed catalyst material are analyzed by X-ray diffraction (XRD), Energy dispersive X-ray diffraction (EDX) mapping and X-ray photoelectron spectroscopy (XPS). The morphology of Co/Al2O3-rGO is characterized by Field-Emission scanning electron microscopy (FE-SEM) and Transmission Electron Microscopy (TEM). A study of different weight percentage of cobalt nanoparticles with support matrix is conducted in respect of catalyst activity and it reveals that the catalyst mixture with 80wt% of metal (Catalyst B) is the best combination compared to the catalyst composition with 70 and 90wt% of metal. Catalyst B also exhibits higher stability compared to the commercial Pt/C catalyst. The function of the nanocatalyst (Catalyst B) as ORR cathode catalyst is observed in a single −chambered microbial fuel cell (SC-MFC) with a power density of 548.19 mWm−2 (compared to 483.48 mWm−2 for Pt/C catalyst).Thus, the newly developed catalyst can be a better substitute for the expensive Pt catalyst for SC-MFC application.