Oxygen-reducing biocathodes operating with passive oxygen transfer in microbial fuel cells

Xue Xia, Justin C. Tokash, Fang Zhang, Peng Liang, Xia Huang, Bruce E. Logan

Research output: Contribution to journalArticle

66 Scopus citations

Abstract

Oxygen-reducing biocathodes previously developed for microbial fuel cells (MFCs) have required energy-intensive aeration of the catholyte. To avoid the need for aeration, the ability of biocathodes to function with passive oxygen transfer was examined here using air cathode MFCs. Two-chamber, air cathode MFCs with biocathodes produced a maximum power density of 554 ± 0 mW/m 2, which was comparable to that obtained with a Pt cathode (576 ± 16 mW/m2), and 38 times higher than that produced without a catalyst (14 ± 3 mW/m2). The maximum current density with biocathodes in this air-cathode MFC was 1.0 A/m2, compared to 0.49 A/m2 originally produced in a two-chamber MFC with an aqueous cathode (with cathode chamber aeration). Single-chamber, air-cathode MFCs with the same biocathodes initially produced higher voltages than those with Pt cathodes, but after several cycles the catalytic activity of the biocathodes was lost. This change in cathode performance resulted from direct exposure of the cathodes to solutions containing high concentrations of organic matter in the single-chamber configuration. Biocathode performance was not impaired in two-chamber designs where the cathode was kept separated from the anode solution. These results demonstrate that direct-air biocathodes can work very well, but only under conditions that minimize heterotrophic growth of microorganisms on the cathodes.

Original languageEnglish (US)
Pages (from-to)2085-2091
Number of pages7
JournalEnvironmental Science and Technology
Volume47
Issue number4
DOIs
StatePublished - Feb 19 2013

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Environmental Chemistry

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