Multicomponent Gas Diffusion in Porous Electrodes
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Bazant_Multicomponent gas.pdf
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1.08 MB
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Checksum (MD5)
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Author(s)
Fu, Yeqing
Jiang, Yi
Poizeau, Sophie
Dutta, Abhijit
Mohanram, Aravind
Pietras, John D.
Bazant, Martin Z.
Date Issued
March 2015
Journal
Journal of the Electrochemical Society
Publisher
Electrochemical Society
Citation
Fu, Y., Y. Jiang, S. Poizeau, A. Dutta, A. Mohanram, J. D. Pietras, and M. Z. Bazant. “Multicomponent Gas Diffusion in Porous Electrodes.” Journal of the Electrochemical Society 162, no. 6 (March 23, 2015): F613–F621.
Version
Final published version
Abstract
Multicomponent gas transport is investigated with unprecedented precision by AC impedance analysis of porous YSZ anode-supported solid oxide fuel cells. A fuel gas mixture of H[subscript 2]-H[subscript 2]O-N[subscript 2] is fed to the anode, and impedance data are measured across the range of hydrogen partial pressure (10–100%) for open circuit conditions at three temperatures (800°C, 850°C and 900°C) and for 300 mA applied current at 800°C. For the first time, analytical formulae for the diffusion resistance (R[subscript b]) of three standard models of multicomponent gas transport (Fick, Stefan-Maxwell, and Dusty Gas) are derived and tested against the impedance data. The tortuosity is the only fitting parameter since all the diffusion coefficients are known. Only the Dusty Gas Model leads to a remarkable data collapse for over twenty experimental conditions, using a constant tortuosity consistent with permeability measurements and the Bruggeman relation. These results establish the accuracy of the Dusty Gas Model for multicomponent gas diffusion in porous media and confirm the efficacy of electrochemical impedance analysis to precisely determine transport mechanisms.
MIT Department
Massachusetts Institute of Technology. Department of Chemical Engineering
Massachusetts Institute of Technology. Department of Mathematics
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DOI of Published Version
https://doi.org/10.1149/2.0911506jes
