Adsorption of trichloro- and trifluoromethane in Y-zeolites as studied by IR spectroscopy and multinuclear solid-state NMR

Abstract

The adsorption of CH(D)Cl₃ and CHF₃ on a series of alkali-exchanged Y-zeolites was studied by ¹H- and ²³Na-NMR and by FTIR spectroscopy. Several adsorption structures were detected which involve H-bonding C–H(D)···O_Z between the acidic C–H(D) group and basic O_Z-framework atoms and between the exchangeable cations and halogen atoms of the probe molecules. ¹H-NMR demonstrated rapid exchange between several adsorption species and IR spectroscopy permitted detection of at least two different species, namely purely H-bonded species I and species II and/or III involving cation–halogen interactions. It is inferred that these species can undergo facile interconversion and that such processes may be involved in the rapid exchange as detected by NMR. Based on ²³Na-NMR results it is concluded that adsorption of CHCl₃ on NaY modifies the negative charge distribution in the zeolite framework. The adsorption-induced C–H(D)-stretching frequency shift of trichloromethane is considered to be a measure of the base strength of the framework O_Z-atoms.

References

1. H. Hattori, Chem. Rev., 1995, 95, 537.
2. Y. Ono and T. Baba, Catal. Today, 1997, 38, 321.
3. H. Knözinger, in Handbook of Heterogeneous Catalysis, ed. G. Ertl, H. Knözinger and J. Weitkamp, Wiley-VCH, Weinheim, 1997, vol. 2, p. 707.
4. D. Barthomeuf, Catal. Rev.-Sci. Eng., 1996, 38, 521.
5. M. Hunger, Solid State Nucl. Magn. Res., 1996, 6, 1.
6. D. Freude, M. Hunger and H. Pfeifer, Z. Phys. Chem., 1987, 152, 171.
7. M. Hunger, D. Freude and H. Pfeifer, J. Chem. Soc., Faraday Trans., 1991, 87, 657.
8. H. Ernst, D. Freude, H. Pfeifer and I. Wolf, Stud. Surf. Sci. Catal., 1994, 84, 381.
9. H. Knözinger and S. Huber, J. Chem. Soc., Faraday Trans., 1998, 94, 2047.
10. M. Hunger, D. Freude, T. Fröhlich, H. Pfeifer and W. Schwieger, Zeolites, 1987, 7, 108.
11. W. P. J. H. Jacobs, J. W. de Haan, L. J. M. van de Ven and R. A. van Santen, J. Phys. Chem., 1993, 97, 10394.
12. M. Hunger, S. Ernst and J. Weitkamp, Zeolites, 1995, 15, 188.
13. J. F. Haw, M. B. Hall, A. E. Alvarado-Swaisgood, E. J. Munson, Z. Lin, L. W. Beck and T. Howard, J. Am. Chem. Soc., 1994, 116, 7308.
14. A. I. Biaglow, R. J. Gorte, G. T. Kokotailo and D. White, J. Catal., 1994, 148, 779.
15. D. Zscherpel, E. Brunner, M. Koch and H. Pfeifer, Micropor. Mater., 1995, 4, 141.
16. A. Michael, W. Meiler, D. Michel and H. Pfeifer, J. Chem. Soc., Faraday Trans., 1986, 82, 3053.
17. H. Knözinger, in Elementary Reaction Steps in Heterogeneous Catalysis, ed. R. W. Joyner and R. A. van Santen, Plenum Press, New York, 1993, p. 267.
18. P. O. Scokart and P. G. Rouxhet, J. Chem. Soc., Faraday Trans., 1980, 76, 1476.
19. D. Barthomeuf, J. Phys. Chem., 1984, 88, 42.
20. E. A. Paukshtis, N. S. Kotsarenko and L. G. Karakchiev, React. Kinet. Catal. Lett., 1979, 12, 315.
21. E. A. Paukshtis, P. I. Soltanov, E. N. Paukshtis, P. I. Soltanov, E. N. Yurchenko and K. Jiratova, Collect. Czech. Chem. Commun., 1982, 47, 2044.
22. E. A. Paukshtis and E. N. Yurchenko, Russ. Chem. Rev., 1983, 52, 242.
23. J. Weitkamp, S. Ernst, M. Hunger, T. Röser, S. Huber, U. A. Schubert, P. Thomasson and H. Knözinger, Stud. Surf. Sci. Catal., 1996, 101, 731.
24. P. S. Kirlin, H. Knözinger and B. C. Gates, J. Phys. Chem., 1990, 94, 8451.
25. G. Kunzmann, Dissertation, Universität München, 1987.
26. E. Brunner, H. Pfeifer, T. Wutscherk and D. Zscherpel, Z. Phys. Chem., 1992, 178, 173.
27. A. Michael, W. Meiler, D. Michel and H. Pfeifer, J. Chem. Soc., Faraday Trans., 1986, 82, 3053.
28. H. K. C. Timken, G. L. Turner, J.-P. Gilson, L. B. Welsh and E. Oldfield, J. Am. Chem. Soc., 1986, 108, 7231.
29. H. K. C. Timken, N. Janes, G. L. Turner, S. L. Lambert, L. B. Welsh and E. Oldfield, J. Am. Chem. Soc., 1986, 108, 7236.
30. U. Fleischer, W. Kutzelnigg, A. Bleiber and J. Sauer, J. Am. Chem. Soc., 1993, 115, 7833.
31. V. M. Mastikhin, I. L. Mudrakovsky and A. V. Nosov, Progr. NMR Spectrosc., 1991, 23, 259.
32. M. Feuerstein, M. Hunger, G. Engelhardt and J. P. Amoureux, Solid State Nucl. Magn. Reson., 1996, 7, 95.
33. S. Huber and H. Knöziner, J. Mol. Catal., in press.
34. S. Bahagavantam, Phys. Rev., 1938, 53, 1015.
35. J. Weidlein, U. Müller and K. Dehnike, in Schwingungsfrequenzen/Band I & II, Georg Thieme Verlag, Stuttgart, New York, 1981.
36. J. Xie, M. Huang and S. Kaliaguine, React. Kinet. Catal. Lett., 1996, 58, 217.
37. R. W. Wood and D. H. Rank, Phys. Rev., 1935, 48, 63.
38. H. J. Bernstein and G. Herzberg, J. Phys. Chem., 1948, 16, 30.
39. C. C. Costain, J. Mol. Spectrosc., 1962, 9, 317.