Iron phthalocyanine and MnOx composite catalysts for microbial fuel cell applications

Richard Burkitt,T.R Whiffen,Eileen Hao Yu

doi:10.1016/j.apcatb.2015.07.010

Richard Burkitt, T.R Whiffen + Show 1 more

Open Access

https://doi.org/10.1016/j.apcatb.2015.07.010

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Abstract

A low cost iron phthalocyanine (FePc)-MnOx composite catalyst was prepared for the oxygen reduction reaction (ORR) in the cathode of microbial fuel cells (MFCs).The catalysts were characterised using rotating ring disc electrode technique. The n number of electrons transferred, and H2O2 production from ORR was investigated. The FePc–MnOx composite catalyst showed higher ORR reduction current than FePc and Pt in low overpotential region. MFC with composite catalysts on the cathode was tested and compared to Pt and FePc cathodes. The cell performance was evaluated in buffered primary clarifier influent from wastewater treatment plant. The membrane-less single chamber MFC generated more power with composite FePcMnOx/MON air cathodes (143mWm−2) than commercial platinum catalyst (140mWm−2) and unmodified FePc/MON (90mWm−2), which is consistent with the RRDE study.The improvement was due to two mechanisms which abate H2O2 release from the composite. H2O2 is the reactant in two processes: (i) chemical regeneration of MnOx after electro-reduction to Mn2+, and (ii) peroxide undergoing chemical disproportionation to O2 and H2O on an electrochemically aged manganese surface retained in the film. Process (i) has the potential to sustain electrochemical reduction of MnOx at cathode potentials as high as 1.0VRHE.

Highlights

Microbial fuel cell (MFC) technology combines the developments in the biotechnology and fuel cell sectors
The number of redox active FePc sites per geometric area (RAS) on the electrode is quantified by charge integration of Fe(II) Pc/Fe(III) Pc oxidation peak in de-aerated medium from 5 mV/s cyclic voltammetry (CV)
This work describes the preparation of a composite oxygen reduction catalyst of iron phthalocyanine and mineralised manganese(III) and (IV) oxides

Summary

Introduction

Microbial fuel cell (MFC) technology combines the developments in the biotechnology and fuel cell sectors. This fusion of capabilities gives MFCs a unique niche. The first large-scale test of MFCs was conducted at Foster’s brewery in Yatala, Queensland in 2009. The performance of the MFC was not known,but the current generation was low due to low conductivity of the brewery wastewater [1]. The first microbial electrolysis cell (MEC) for hydrogen production was set up at the Napa Wine Company, USA, in 2009 [1]. Another pilot scale MEC for (E.H. Yu)

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