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Monitoring of Electrochemical Processes in Catalysts by Microwave Methods

  • Gerhard Fischerauer
  • Andreas Gollwitzer
  • Alexander Nerowski
  • Matthias Spörl
  • Sebastian Reiß
  • Ralf Moos
Chapter

Abstract

Many electrochemical reactions occur at high temperatures and inside bulk materials. Because of the difficulties associated with a direct observation of the reaction, one often resorts to indirect measurement strategies. An example is the three-way catalyst (TWC) in the exhaust pipe of a gasoline engine which stores oxygen when it is abundant in the exhaust gas and releases it later to oxidize noxious gas components such as CO in oxygen-deficient (“lean”) exhaust gases. Currently, the oxygen loading of the TWC is derived indirectly from the output signals of two lambda probes, one upstream and the other downstream of the catalyst, which monitor the air-to-fuel ratio λ in the exhaust gas. We have investigated a microwave cavity perturbation approach towards the direct measurement of the catalyst state. It will be shown that the uptake or release of oxygen in the catalyst is observable in situ via the S-parameters of a cavity resonator.

Keywords

Cavity Resonator Exhaust Pipe Perfect Electric Conductor Transverse Magnetic Mode Transverse Electric Mode 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgements

This work was supported by the German Research Foundation (DFG), grants number Fi 956/3–1 and Mo 1060/6–1. The authors are indebted to Drs. Ulrich Göbel, Jürgen Gieshoff, and Martin Rösch from Umicore, Hanau, Germany who provided TWC samples.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • Gerhard Fischerauer
    • 1
  • Andreas Gollwitzer
    • 2
  • Alexander Nerowski
    • 3
  • Matthias Spörl
    • 4
  • Sebastian Reiß
  • Ralf Moos
  1. 1.Bayreuth Engine Research Center (BERC), Faculty of Engineering ScienceUniversity of BayreuthBayreuthGermany
  2. 2.University of Applied Sciences FurtwangenFurtwangen im SchwarzwaldGermany
  3. 3.Technical University of DresdenFurtwangen im SchwarzwaldGermany
  4. 4.BayreuthGermany

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