Synthesis, characterization and catalytic activity of amorphous Al,SiO_x gels from weakly acidic aqueous solutions

Abstract

Al,SiO_xgels have been prepared by reaction of different inorganic aluminium compounds with silicic acid. Characterization by chemical analysis,²⁷Al MAS NMR spectroscopy and adsorption measurements shows that the gels obtained from a mixture (pH ca. 3) of basic aluminium chlorides and silicic acid in water are porous and contain tetrahedrally coordinated aluminium in the framework. IR spectroscopy and TPDA measurements confirm that Brønsted and Lewis acid sites are present in the gels. Finally, catalytic activity was found in hex-1-ene isomerization.

References

1. T. Lopez, M. Asomoza and R. Gomez, J. Non-Cryst. Solids, 1992, 147/148, 769.
2. S. Rouanet, R. J. Willey and J. B. Peri, Sol Gel Processing and Applications, ed. Y. A. Attia, Plenum Press, New York, 1994, p. 285.
3. G. Bellussi, C. Perego, A. Carati, S. Preatello, E. Previde Massara and G. Perego, Stud. Surf. Sci. Catal., 1994, 84, 85.
4. M. Toba, F. Mizukami, S. Niwa, T. Sano, K. Maeda and H. Shoji, J. Mater. Chem., 1994, 4, 1131.
5. Y. Matsumoto, K. Mita, K. Hashimoto and T. Tokoroyama, Appl. Catal., 1995, 131, L1.
6. S. D. Jones, T. N. Pritchard and D. F. Lander, Microporous Mater., 1995, 3, 419.
7. K. P. Wendlandt, H. Bremer, M. Jank, M. Weber, P. Starke and D. Müller, Acta Phys. Chem., 1985, 31, 35.
8. B. M. De Witte, P. J. Grobet and J. B. Uytterhoeven, J. Phys. Chem., 1995, 99, 6961.
9. R. Bertram, W. Geβner, D. Müller, H. Görz and S. Schönherr, Z. Anorg. Allg. Chem., 1985, 525, 14.
10. S. Schönherr, H. Görz, D. Müller and W. Geβner, Z. Anorg. Allg. Chem., 1981, 476, 188.
11. I. Jaymes and A. Douy, J. Eur. Ceram. Soc., 1996, 16, 155.
12. M. Fukuoka, Y. Onoda, S. Inoue, K. Wada, A. Nukui and A. Makishima, J. Sol Gel Sci. Tech., 1993, 1, 47.
13. B. M. De Witte, K. Aernouts and J. B. Uytterhoeven, Microporous Mater., 1996, 7, 97.
14. D. Müller, D. Hoebbel and W. Geβner, Chem. Phys. Lett., 1981, 84, 25.
15. G. Engelhardt and D. Michel, High-resolution NMR of Silicates and Zeolites, Wiley, Chichester, 1987.
16. S. J. Gregg and K. S. W. Sing, Adsorption, Surface Area and Porosity, Academic Press, London, 1991, ch. 1.
17. N. Y. Topsoe, K. Pedresen and E. Derouane, J. Catal., 1981, 70, 41.
18. P. A. Jacobs and R. von Ballmoos, J. Phys. Chem., 1982, 86, 3050.
19. A. A. Davydov, Infrared spectroscopy of adsorbed species on the surface of transition metals oxides, John Wiley & Sons, 1990, p. 26.
20. U. Kürschner, H.-G. Jerschkewitz, E. Schreier and J. Völter, Appl. Catal., 1990, 57, 167.