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Catalysis Letters

, Volume 24, Issue 3–4, pp 235–248 | Cite as

Characterization of acid properties of [Al]- and [Ga]-HZSM-5 zeolites by low temperature Fourier transform infrared spectroscopy of adsorbed carbon monoxide

  • Ibad Mirsojew
  • Stefan Ernst
  • Jens Weitkamp
  • Helmut Knözinger
Article

Abstract

[Al]- and [Ga]-HZSM-5 having closely similar acid site densities were prepared. Temperature-programmed desorption of ammonia (TPDA) proved the known acid strength sequence: [Al]>[Ga]. Frequency shifts of the OH stretching mode to lower frequencies were induced upon CO adsorption at 77 K due to OH ⋯ CO H-bonding interactions. These frequency shifts are a measure of the H-bond donor strength of the OH groups and hence, of their acidic strength. The observed shifts of 313 and 282 cm−1 for the [Al]- and [Ga]-silicate, respectively, clearly reflect their relative acid strength. [Ga]-HZSM-5 develops an acid strength similar to that found for HNaY at high exchange levels. Evidence is presented for an intrinsic heterogeneity of acid properties of the acidic hydroxyls probably caused by inhomogeneous distributions of the trivalent cations in the framework.

Keywords

Acidity [Al]-HZSM-5 [Ga]-HZSM-5 HNaY CO-adsorption FTIR-spectroscopy 

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References

  1. [1]
    H.-P. Boehm and H. Knözinger, in:Catalysis — Science and Technology, eds. J.R. Anderson and M. Boudart (Springer, Berlin, 1983) p. 39.Google Scholar
  2. [2]
    E.A. Paukshtis and E.N. Yurchenko, Russ. Chem. Rev. 52 (1983) 242.Google Scholar
  3. [3]
    M.I. Zaki and H. Knözinger, Mater. Chem. Phys. 17 (1987) 201.Google Scholar
  4. [4]
    H. Knözinger, in:Acid-Base Catalysis, eds. K. Tanabe, H. Hattori, T. Yamaguchi and T. Tanaka (Kodansha/Verlag Chemie, Tokyo/Weinheim, 1989) p. 147.Google Scholar
  5. [5]
    M.I. Zaki and H. Knözinger, J. Catal. 119 (1989) 311.Google Scholar
  6. [6]
    G. Ghiotti, E. Garrone, C. Morterra and F. Boccuzzi, J. Phys. Chem. 83 (1979) 2863.Google Scholar
  7. [7]
    T.P. Beebe, P. Gelin and J.T. Yates Jr., Surf. Sci. 148 (1984) 526.Google Scholar
  8. [8]
    L.M. Kustov, V.B. Kazansky, S. Beran, L. Kubelková and P. Jiru, J. Phys. Chem. 91 (1987) 5247.Google Scholar
  9. [9]
    L. Kubelková, S. Beran and J.A. Lercher, Zeolites 9 (1989) 539.Google Scholar
  10. [10]
    N. Echoufi and P. Gélin, J. Chem. Soc. Faraday Trans. 88 (1992) 1067.Google Scholar
  11. [11]
    A. Zecchina, S. Bordiga, G. Spoto, L. Marchese, G. Petrini, G. Leofanti and M. Padovan, J. Phys. Chem. 96 (1992) 4991.Google Scholar
  12. [12]
    A. Zecchina, S. Bordiga, G. Spoto, D. Scarano, G. Petrini, G. Leofanti, M. Padovan and C. Otero Areán, J. Chem. Soc. Faraday Trans. 88 (1992) 2959.Google Scholar
  13. [13]
    T. Chevreau, S. Khabtou, M. Maache, A. Janin and J.C. Lavalley,Proc. 9th Int. Zeolite Conf., Montreal 1992, Book of Abstracts, eds. J.B. Higgins, R. von Ballmoos and M.M.J. Treacy (Butterworth-Heinemann, London) RP 92.Google Scholar
  14. [14]
    B. Umansky, J. Engelhardt and W.K. Hall, J. Catal. 127 (1991) 128.Google Scholar
  15. [15]
    M. Thielen, M. Geelen and P.A. Jacobs,Proc. Int. Symp. on Zeolite Catalysis, Siofok 1985, Acta Physica et Chemica Szegediensis (1985) p. 1.Google Scholar
  16. [16]
    C.T.W. Chu and C.D. Chang, J. Phys. Chem. 89 (1985) 1569.Google Scholar
  17. [17]
    M.F.M. Post, T. Huizinga, C.A. Emeis, J.M. Nanne and W.H.J. Stork, in:Zeolites as Catalysts, Sorbents and Detergent Builders — Applications and Innovations, eds. H.G. Karge and J. Weitkamp (Elsevier, Amsterdam, 1989) p. 365.Google Scholar
  18. [18]
    J. Weitkamp, H.K. Beyer, G. Borbély, V. Cortes-Corberán and S. Ernst, Chem.-Ing.-Techn. 58 (1986) 969.Google Scholar
  19. [19]
    G. Kunzmann, Doctoral Thesis, University of Munich, Germany (1987).Google Scholar
  20. [20]
    A.G. Pelmenschikov, G. Morosi and A. Gamba, J. Phys. Chem. 95 (1991) 10037.Google Scholar
  21. [21]
    H.G. Karge, J. Ladebeck, Z. Sarbak and K. Hatada, Zeolites 2 (1982) 94.Google Scholar
  22. [22]
    G.J. Kramer, A.J.M. de Man and R.A. van Santen, J. Am. Chem. Soc. 113 (1991) 6435.Google Scholar
  23. [23]
    R.A. van Santen, G.J. Kramer and W.P.J.H. Jacobs, in:Elementary Reaction Steps in Heterogeneous Catalysis, eds. R.W. Joyner and R.A. van Santen (Plenum Press, New York, 1993) p. 113.Google Scholar
  24. [24]
    A.G. Pelmenschikov, V.I. Pavlov, G.M. Zhidomirov and S. Beran, J. Phys. Chem. 91 (1987) 3325.Google Scholar
  25. [25]
    E. Dima and L.V.C. Rees, Zeolites 7 (1987) 219.Google Scholar
  26. [26]
    H.G. Karge, V. Dondur and J. Weitkamp, J. Phys. Chem. 95 (1991) 283.Google Scholar
  27. [27]
    G.J. Kramer and R.A. van Santen, J. Am. Chem. Soc. 115 (1993) 2887.Google Scholar

Copyright information

© J.C. Baltzer AG, Science Publishers 1994

Authors and Affiliations

  • Ibad Mirsojew
    • 1
  • Stefan Ernst
    • 2
  • Jens Weitkamp
    • 2
  • Helmut Knözinger
    • 1
  1. 1.Institut für Physikalische ChemieUniversität MünchenMunichGermany
  2. 2.Institut für Technische Chemie IUniversität StuttgartStuttgartGermany

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