Novel Gas Diffusion Cloth Bioanodes for High-Performance Methane-Powered Microbial Fuel Cells

Area of Science:

• Electrochemistry
• Environmental Science
• Microbiology

Background:

• Microbial fuel cells (MFCs) offer a sustainable method for converting chemical energy into electricity.
• Limited performance of existing MFCs powered by gas fuels like methane is attributed to low gas solubility and bioavailability.
• Development of efficient anodes is crucial for enhancing MFC performance, particularly for gaseous substrates.

Purpose of the Study:

• To develop an enhanced anode for methane-powered microbial fuel cells (MFCs).
• To significantly improve the current density and power output of MFCs utilizing methane as fuel.
• To investigate the microbial community structure and function within the novel anode biofilm.

Main Methods:

• Fabrication of a gas diffusion cloth (GDC) anode by coating waterproof GORE-TEX cloth with conductive carbon cloth.
• Biofilm enrichment on the GDC anodes using methane as the primary substrate.
• Electrochemical performance testing, including current density and power density measurements.
• Microbial community analysis using Illumina high-throughput sequencing.

Main Results:

• The GDC anodes achieved a methane-dependent current density of 1130.2 mA m⁻², representing a 165.2-fold enhancement over conventional carbon cloth anodes.
• MFCs equipped with GDC anodes demonstrated a maximum power density of 419.5 mW m⁻².
• Microbial analysis revealed a distinct biofilm community dominated by Geobacter on GDC anodes, differing from planktonic communities.
• Hypothesized microbial pathways involve Methanobacterium reversing methanogenesis and Geobacter generating electricity from anaerobic methane oxidation intermediates.

Conclusions:

• The developed GDC anode is a facile, cost-effective, and highly effective solution for enhancing methane-powered MFC performance.
• This approach significantly overcomes the limitations of gas solubility and bioavailability in MFCs.
• The study provides a promising strategy for developing high-performance MFCs for sustainable energy generation from methane.