Lead dioxide as an alternative catalyst to platinum in microbial fuel cells

Lead dioxide (PbO2) was compared to platinum (Pt) as a cathode catalyst in a double-cell microbial fuel cell (MFC) utilizing glucose as a substrate in the anode chamber. Four types of cathodes were tested in this study including two PbO2 cathodes fabricated using a titanium base with butanol or Nafion binders and PbO2 paste, one Pt/carbon cathode fabricated using a titanium base with a carbon-Pt paste, and a commercially available Pt/carbon cathode made from carbon paper with Pt on one side. The power density and polarization curves were compared for each cathode and cost estimates were calculated. Results indicate the PbO2 cathodes produced between 2 and 4x more power than the Pt cathodes. Furthermore, the PbO2 cathodes produced between 2 and 17x more power per initial fabrication or purchase cost than the Pt cathodes. This study suggests that cathode designs that incorporate PbO2 instead of Pt could possibly improve the feasibility of scaling up MFC designs for real world applications by improving power generation and lowering production cost. (C) 2007 Elsevier B.V. All rights reserved.