Impedance Characterization of a Model Au/Yttria-Stabilized Zirconia (YSZ)/Au Electrochemical Cell in Varying Oxygen and NOx Concentrations [electronic resource].
- Published
- Washington, D.C. : United States. Dept. of Energy, 2006.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy. - Physical Description
- PDF-file: 43 pages; size: 1.1 Mbytes
- Additional Creators
- Lawrence Berkeley National Laboratory, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information
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- Restrictions on Access
- Free-to-read Unrestricted online access
- Summary
- An electrochemical cell (Au/YSZ/Au) serves as a model system to investigate the effect of O₂ and NOₓ. Possible mechanisms responsible for the response are presented. Two dense Au electrodes are co-located on the same side of a dense YSZ electrolyte and are separated from the electrolyte by a porous YSZ layer, present only under the electrodes. While not completely understood, the porous layer appears to result in enhanced NOₓ response. Impedance data were obtained over a range of frequencies (0.1 Hz to 1 MHz), temperatures (600 to 700 C), and oxygen (2 to 18.9%) and NOₓ (10 to 100 ppm) concentrations. Spectra were fit with an equivalent circuit, and values of the circuit elements were evaluated. In the absence of NOₓ, the effect of O₂ on the low-frequency arc resistance could be described by a power law, and the temperature dependence by a single apparent activation energy at all O₂ concentrations. When both O₂ and NOₓ were present, however, the power-law exponent varied as a function of both temperature and concentration, and the apparent activation energy also showed dual dependence. Adsorption mechanisms are discussed as possibilities for the rate-limiting steps. Implications for impedance metric NOₓ sensing are also discussed.
- Report Numbers
- E 1.99:ucrl-jrnl-225792
ucrl-jrnl-225792 - Subject(s)
- Other Subject(s)
- Note
- Published through SciTech Connect.
11/01/2006.
"ucrl-jrnl-225792"
Journal of the Electrochemical Society, vol. 154, no. 4, February 15, 2007, J129-J135 154 4 ISSN 0013-4651; JESOAN FT
Glass, R S; Martin, L P; Woo, L Y; Gorte, R J. - Funding Information
- W-7405-ENG-48
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