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Reaction Kinetics, Mechanisms and Catalysis

, Volume 104, Issue 2, pp 303–309 | Cite as

Light alkane aromatization over modified Zn-ZSM-5 catalysts: characterization of the catalysts by hydrogen/deuterium isotope exchange

  • Krisztina Frey
  • Louis M. Lubango
  • Mike S. Scurrell
  • László Guczi
Article

Abstract

The selectivity obtained in the aromatization of propane over Zn-ZSM-5-based catalysts (Si/Al nominal ratio = 35) increased from about 69% (carbon basis) to 74–91% when a second transition metal ion is introduced into the catalyst. The effect, previously reported for the case of Fe3+ ions, has now been shown to be more general and is seen also for the ions of chromium, cobalt or manganese. It is likely that these ions are present under aromatization conditions in a partially reduced state. H2/D2 isotope exchange rates show large enhancements on the reduced Fe-Zn/ZSM-5 and Co-Zn/ZSM-5 samples. This aspect of aromatization catalysis has not been reported before.

Keywords

Aromatization Alkanes Zinc-zeolites Transition metal ions H2/D2 exchange 

Notes

Acknowledgments

One of us (LML) thanks the National Research Foundation and the Molecular Sciences Institute of the School of Chemistry, University of the Witwatersrand, Johannesburg, for financial support. The authors are indebted to ERACHEMISTRY for partial financial support (grant # 75009) and for OTKA grants (NNF 78837 and NNF2 85631). The research was coordinated by Hungarian—South-African intergovernmental S & T co-operation program.

References

  1. 1.
    Nicolaides CP, Sincadu NP, Scurrell MS (2001) Catal Today 71:429–435CrossRefGoogle Scholar
  2. 2.
    Biscadi JA, Iglesia E (1999) J Catal 182:117–128CrossRefGoogle Scholar
  3. 3.
    Gosling CD, Wilcher FP, Sullivan L, Mountford RA (1991) Hydrocarb Proc Dec 69Google Scholar
  4. 4.
    Scurrell MS (1988) Appl Catal 41:89–98CrossRefGoogle Scholar
  5. 5.
    Mole T, Anderson JR, Creer G (1985) Appl Catal 17:141–154CrossRefGoogle Scholar
  6. 6.
    Nicolaides CP, Sincadu NP, Scurrell MS (2001) Stud Surf Sci Catal 136:333CrossRefGoogle Scholar
  7. 7.
    Biscardi JA, Meitzner GD, Iglesia E (1998) J Catal 179:192–202CrossRefGoogle Scholar
  8. 8.
    Kim Y-H, Borry RW III, Iglesia E (2000) Microporous Mesoporous Mater 35–36:495–509CrossRefGoogle Scholar
  9. 9.
    Heylen CF, Jacobs PA, Uytterhoeven JB (1976) J Catal 43:99–110CrossRefGoogle Scholar
  10. 10.
    Lubango LM, Scurrell MS (2002) Appl Catal A Gen 235:265–272CrossRefGoogle Scholar
  11. 11.
    Isotopes in Heterogeneous Catalysis, Chapter 6, Justin SJ, Hargreaves S, David J, Geoff W (2006) (eds)Google Scholar
  12. 12.
    Benkhaled M, Descorme C, Duprez D, Morin S (2008) Appl Catal A General 346:36–43CrossRefGoogle Scholar
  13. 13.
    Wilson RL, Kemball C, Galwey AK (1962) Trans Faraday Soc 58:583CrossRefGoogle Scholar
  14. 14.
    Chen HY, Sachtler WMH (1998) Catal Lett 50:125–130CrossRefGoogle Scholar
  15. 15.
    Berndt H, Lietz G, Volter J (1996) Appl Catal A Gen 146:365–379CrossRefGoogle Scholar
  16. 16.
    Iglesia E, private communicationGoogle Scholar
  17. 17.
    Kazansky VB, Bororkov VY, Serikh AI, van Santen RA, Anderson BG (2000) Catal Lett 66:39–47CrossRefGoogle Scholar
  18. 18.
    Kazansky VB, Serykh AI, van Santen RA, Anderson BG (2001) Catal Lett 74:55–59CrossRefGoogle Scholar
  19. 19.
    Lubango LM, Scurrell MS (2002) Appl Catal A General 235:265–272CrossRefGoogle Scholar

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2011

Authors and Affiliations

  • Krisztina Frey
    • 1
  • Louis M. Lubango
    • 2
  • Mike S. Scurrell
    • 2
  • László Guczi
    • 1
  1. 1.Department of Surface Chemistry and CatalysisInstitute of IsotopesBudapestHungary
  2. 2.School of Chemistry, Molecular Sciences InstituteUniversity of the Witwatersrand JohannesburgJohannesburgSouth Africa

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