Topics in Catalysis

, Volume 52, Issue 13–20, pp 2035–2040 | Cite as

Direct Catalyst Monitoring by Electrical Means: An Overview on Promising Novel Principles

  • Ralf MoosEmail author
  • Marion Wedemann
  • Matthias Spörl
  • Sebastian Reiß
  • Gerhard Fischerauer
Original Paper


By measuring the electrical properties of the catalyst coating itself, one can observe directly and in situ the state of TWC, LNT, and SCR catalysts. Two principles are possible: a contact method, for which the coating is applied to planar electrodes and the electrical impedance is measured, and a non-contact method, in which the coating material is penetrated by radio frequency waves. In either case, the catalyst state is directly correlated with the measured transmission or reflection characteristics of the electrical sensors.


Catalyst status detection On-Board Diagnosis (OBD) Exhaust gas sensor TWC LNT 



The authors are indebted to Umicore (Dr. J. Gieshoff, Dr. U. Göbel, Dr. M. Rösch, Dr. M. Votsmeier) for providing catalyst samples.


  1. 1.
    Riegel J, Neumann H, Wiedenmann H-M (2002) Solid State Ionics 152–153:783CrossRefGoogle Scholar
  2. 2.
    Moos R (2005) Int J Appl Ceram Technol 2:401CrossRefGoogle Scholar
  3. 3.
    Twigg MV (2007) Appl Catal B Environ 70:2CrossRefGoogle Scholar
  4. 4.
    Kato N, Nakagaki K, Ina N (1996) SAE paper 960334Google Scholar
  5. 5.
    Waltner A et al (2006) Twenty-seventh international Vienna motor symposium, April 2006Google Scholar
  6. 6.
    Kim YW, Van Nieuwstadt M (2006) SAE paper 2006-01-3548Google Scholar
  7. 7.
    Moos R, Schönauer D (2008) Sens Lett 6:821CrossRefGoogle Scholar
  8. 8.
    Wang DY, Yao S, Shost M, Yoo JH, Cabush D, Racine D, Cloudt R, Willems F (2008) SAE paper 2008-01-0919Google Scholar
  9. 9.
    Moos R, Müller R, Plog C, Knezevic A, Leye H, Irion E, Braun T, Marquardt K-J, Binder K (2002) Sens Actuator B Chem 83:181CrossRefGoogle Scholar
  10. 10.
    Schär CM, Onder CH, Geering HP, Elsener M (2003) SAE paper 2003-01-0776Google Scholar
  11. 11.
    Riegel J, Klett S (2008) Sensors for modern exhaust gas aftertreatment systems. Proceedings, 5th international exhaust gas and particulate emissions forum, Ludwigsburg, Germany, p 85Google Scholar
  12. 12.
    Barsoukov E, MacDonald JR (2005) Impedance spectroscopy. Wiley, Hobken, NYCrossRefGoogle Scholar
  13. 13.
    Birkhofer T, Knezevic A, Leye H, Moos R, Plog C, Ried T, Voigtländer D (2003) US patent specification US 6,619,108Google Scholar
  14. 14.
    Nohira H, Nakanishi K, Iguchi S, Kihara T, Muraka H (1991) European patent specification, EP 0573672Google Scholar
  15. 15.
    Zimmermann C (2007) Neuartiger Sensor zur Bestimmung des Zustandes eines NOx-Speicherkatalysators (Novel sensor for determining the state of a NOx storage catalyst), Ph.D. thesis, University of BayreuthGoogle Scholar
  16. 16.
    Moos R, Zimmermann C, Birkhofer T, Knezevic A, Plog C, Busch MR, Ried T (2008) SAE paper 2008-01-0447Google Scholar
  17. 17.
    Hammerle R, Urea SCR (2002) DPF system for diesel sport utility vehicle meeting tier II bin 5. Eighth diesel engine emissions reduction (DEER) workshop, San Diego, CAGoogle Scholar
  18. 18.
    Kubinski DJ, Visser JH (2008) Sens Actuator B Chem 130:425CrossRefGoogle Scholar
  19. 19.
    Binder K, Braun T, Knezevic A, Busch MR, Marquardt K-J, Moos R, Plog C (2004) US patent specification US 6,833,272Google Scholar
  20. 20.
    Reiß S, Wedemann M, Moos R, Rösch M (2009) Top Catal. doi: 10.1007/s11244-009-9366-2
  21. 21.
    Tuller HL, Nowick AS (1979) J Electrochem Soc 126:209CrossRefGoogle Scholar
  22. 22.
    Moos R, Härdtl KH (1997) J Am Ceram Soc 80:2549CrossRefGoogle Scholar
  23. 23.
    Izu N, Itoh T, Shin W, Matsubara I, Murayama N (2008) Sens Actuator B Chem 130:466CrossRefGoogle Scholar
  24. 24.
    Collin RE (2001) Foundations for microwave engineering. IEEE press, New YorkGoogle Scholar
  25. 25.
    Fischerauer G, Spörl M, Gollwitzer A, Wedemann M, Moos R (2008) Frequenz 62:180Google Scholar
  26. 26.
    Fischerauer G, Gollwitzer A, Nerowski A, Spörl M, Moos R (2009) On the inverse problem associated with the observation of electrochemical processes by the RF cavity perturbation method. Sixth international multi-conf. on systems, signals & devices (SSD ‘09), Djerba, Tunisia, March 23–26, 2009Google Scholar
  27. 27.
    Moos R, Spörl M, Hagen G, Gollwitzer A, Wedemann M, Fischerauer G (2008) SAE paper 2008-01-0916Google Scholar

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Ralf Moos
    • 1
    Email author
  • Marion Wedemann
    • 1
  • Matthias Spörl
    • 1
  • Sebastian Reiß
    • 1
  • Gerhard Fischerauer
    • 1
  1. 1.Bayreuth Engine Research CenterBayreuthGermany

Personalised recommendations