Structural changes in mordenite during its dealuminization

  • G. K. Beier
  • I. M. Belen'kaya
  • M. M. Dubinin
  • F. Khange
Physical Chemistry

Conclusions

  1. 1.

    Treatment with acids leads to the dealuminization of mordenite, condensation of pairs of hydroxyl groups in alternate hydroxyl clusters carrying five-membered rings over to four-membered rings. Dehydroxylation proceeds in such way that two OH groups are first eliminated from each of the hydroxyl clusters, without any loss of crystallinity. Loss of crystallinity is observed only on eliminating the second pair of OH groups from the cluster.

     
  2. 2.

    Hydrothermal treatment of the acid-dealuminized mordenite gives a product with enhanced structural stability. This effect results from the healing of vacancies induced by dealuminization, and from an increase in anion skeleton Si/Al ratio arising from Si and O atom migration, the situation here being similar to that met in the hydrothermal stabilization of H-zeolite.

     
  3. 3.

    The data suggest that the aluminum atoms which leave the H-mordenite lattice during dehydroxylation do not pass over into the cation state.

     

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Literature cited

  1. 1.
    G. H. Kühl, Proceedings, Third International Conference on Molecular Sieves, Leuven University Press, Leuven (1973), p. 227.Google Scholar
  2. 2.
    R. M. Barrer and J. Klinowski, J. Chem. Soc. Faraday Trans, 1,71, 690 (1975).Google Scholar
  3. 3.
    P. A. Jacobs and H. K. Beyer, J. Phys. Chem.,83, 1174 (1979).Google Scholar
  4. 4.
    G. T. Kerr, J. Phys. Chem.,71, 4155 (1967).Google Scholar
  5. 5.
    G. T. Kerr, J. Catal.,15, 200 (1969).Google Scholar
  6. 6.
    P. A. Jacobs and J. B. Uytterhoeven, J. Catal.,22, 193 (1971).Google Scholar
  7. 7.
    P. K. Maher, F. D. Hunter, and J. Scherzer, Ad. Chem. Ser.,101, 266 (1971).Google Scholar
  8. 8.
    P. Gallezot, R. Beaumont, and D. Barthomeuf, J. Phys. Chem.,78, 1550 (1974).Google Scholar
  9. 9.
    J. Scherzer and J. L. Bass, J. Catal.,28, 101 (1973).Google Scholar
  10. 10.
    P. Pichat, R. Beaumont, and D. Barthomeuf, J. Chem. Soc. Faraday Trans, 1,70, 1402 (1974).Google Scholar
  11. 11.
    I. Belenykaja (Belen'kaya), H. K. Beyer, A. Kiss, and J. Mihályfi, Proceedings, Second Bulgaro-Soviet Symposium on Natural Zeolites, Krdshali (1979).Google Scholar
  12. 12.
    J. C. Vedrine, A. Abou-Kais, J. Massardier, and G. Dalmai-Imelik, J. Catal.,29, 120 (1973).Google Scholar
  13. 13.
    I. M. Belen'kaya, M. M. Dubinin, and I. I. Krishtofori, Izv. Akad. Nauk SSSR, Ser. Khim., 2164 (1967).Google Scholar
  14. 14.
    I. M. Belen'kaya, M. M. Dubinin, and I. I. Krishtofori, Izv. Akad. Nauk SSSR, Ser. Khim., 2184 (1968).Google Scholar
  15. 15.
    R. M. Barrer and M. B. Makki, Can. J. Chem.,42, 1481 (1964).Google Scholar
  16. 16.
    Z. I. Koridze, A. Yu. Krupennikova, and T. G. Andronikashvili, Proceedings of a Symposium on the Study and Applications of Clinoptilolite [in Russian], Tbilisi (1977), p. 96.Google Scholar
  17. 17.
    R. M. Barrer and D. L. Peterson, Proc. Roy. Soc.,280A, 466 (1964).Google Scholar
  18. 18.
    I. M. Belen'kaya, M. M. Dubinin, and I. I. Krishtofori, Izv. Akad. Nauk SSSR, Ser. Khim., 2635 (1971).Google Scholar
  19. 19.
    I. V. Mishin, G. A. Piloyan, A. L. Klyachko-Gurvich, and A. M. Rubinshtein, Izv. Akad. Nauk SSSR, Ser. Khim., 1343 (1973).Google Scholar
  20. 20.
    D. K. Thakur and S. W. Weller, Adv. Chem. Ser.,121, 596 (1973).Google Scholar
  21. 21.
    F. Wolf and H. John, Chem. Techn.,26, 159 (1974).Google Scholar
  22. 22.
    H. K. Beyer and I. Belenykaja, Stud. Surf. Sci. Catal.,5, 203 (1980).Google Scholar
  23. 23.
    J. Scherzer, J. Catal.,54, 285 (1978).Google Scholar
  24. 24.
    U. Lohse, E. Alsdorf, and H. Stach, Z. Anorg. Allg. Chem.,447, 64 (1978).Google Scholar
  25. 25.
    E. M. Flanigen, in: Zeolite Chemistry and Catalysis (ed. by J. A. Rabo), American Chemical Society, Washington (1976), p. 80.Google Scholar

Copyright information

© Plenum Publishing Corporation 1983

Authors and Affiliations

  • G. K. Beier
    • 1
    • 2
  • I. M. Belen'kaya
    • 1
    • 2
  • M. M. Dubinin
    • 1
    • 2
  • F. Khange
    • 1
    • 2
  1. 1.Institute of Physical ChemistryAcademy of Sciences of the USSRMoscow
  2. 2.Central Scientific-Research Institute for ChemistryHungarian Academy of SciencesUSSR

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