Mixed potential in a direct methanol fuel cell

Fuqiang Liu, Chao-yang Wang

Research output: Contribution to journalArticle

56 Citations (Scopus)

Abstract

A mathematical model for the cathode of a direct methanol fuel cell (DMFC) is developed to investigate two-phase transport in the catalyst layer (CL) and to elucidate the mechanism of cathode mixed potential due to oxidation of crossover methanol. A coupled model of two-phase species transport and multistep electrochemical kinetics, including simultaneous oxygen reduction, methanol oxidation, and gas phase chemical reaction, is presented. The model predictions agree favorably with experiments of cathode mixed potential, and the predicted profiles of water saturation, oxygen concentration, and overpotential along the CL thickness further reveal the profound interplay between multiple reactions and the transport of oxygen and water. It is shown that in the presence of methanol crossover, the DMFC cathode is operated at higher overpotential and water saturation, with larger oxygen transport loss than that in the H2 /air counterpart. The model results also indicate that reducing the cathode CL thickness can facilitate both liquid water removal and oxygen transport through the CL, leading to improved cathode performance.

Original languageEnglish (US)
JournalJournal of the Electrochemical Society
Volume154
Issue number6
DOIs
StatePublished - Aug 1 2007

Fingerprint

Direct methanol fuel cells (DMFC)
fuel cells
Cathodes
methyl alcohol
cathodes
Oxygen
oxygen
catalysts
Methanol
Catalysts
Water
water
crossovers
cell cathodes
saturation
oxidation
Oxidation
mathematical models
chemical reactions
Chemical reactions

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Materials Chemistry
  • Electrochemistry

Cite this

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Mixed potential in a direct methanol fuel cell. / Liu, Fuqiang; Wang, Chao-yang.

In: Journal of the Electrochemical Society, Vol. 154, No. 6, 01.08.2007.

Research output: Contribution to journalArticle

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