Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-25T18:39:11.559Z Has data issue: false hasContentIssue false

Synthesis of Large ZSM-5 Crystals under High Pressure

Published online by Cambridge University Press:  18 March 2011

Allan J. Jacobson
Affiliation:
Department of Chemistry and Materials Research Science and Engineering Center, University of Houston, Houston, Texas 77204-5641
Get access

Abstract

The synthesis temperature for silicalite-I (MFI) can be raised to 300°C by applying high pressure to stabilize the structure-directing organic template. The elevated temperature and pressure favor theformation of crystals with improved quality. Prismatic silicalite-I crystals with a uniform size of about 0.7× 0.2 × 0.2 mm have been obtained by heating a gel prepared from TMA-silicate solution, TPABr andsodium hexafluorosilicate at 250°C under a pressure of 80 MPa. The influence of synthesis conditions on the crystal sizes has been studied by systematically changing temperature, pressure and gel compositions. Underthe specific conditions of 250°C and 80 MPa, a strong correlation was found between the crystal size andthe F/Si mole ratio of the starting gel, which enables the preparation of uniform crystals of silicalite-I with preset dimensions.

Type
Research Article
Copyright
Copyright © Materials Research Society 2000

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Charnell, J. F., J. Crystal Growth, 8, 291 (1971).Google Scholar
2. Kuperman, A., Nadimi, S., Oliver, S., Ozin, G. A., Garces, J. and Olken, M. M., Nature, 365, 239 (1993).Google Scholar
3. Klemperer, W. G. and Marquart, T. A., Mat. Res. Soc. Symp. Proc., 346, 819 (1994).Google Scholar
4. Qiu, S., Yu, J., Zhu, G., Tarasaki, O., Nozue, Y., Pang, W. and Xu, R., Microporous and Mesoporous Mater., 21, 245 (1998).Google Scholar
5. Wang, X. and Jacobson, A. J., J. Chem. Soc., Chem. Commun., 1999, 973.Google Scholar
6. Ghobarkar, H., Schaf, O. and Guth, U., Prog. Solid St. Chem., 27, 29 (1999).Google Scholar
7. Guth, J. L., Kessler, H. and Wey, R., in Proc. 7th Intern. Conference on Zeolite, Elsevier, Tokyo, 121 (1986).Google Scholar
8. Jansen, J. C., Engelen, C. W. R. and Bekkum, H. van, in Amer. Chem. Soc. Symp. Series 398, 257 (1989).Google Scholar
9. Galli, E., Vezzalini, G., Quartieri, S., Alberti, A. and Franzini, M., Zeolite, 19, 318 (1997).Google Scholar
10. Sheldrick, G. M., SHELXTL, Version 5.03, Siemens Analytical X-ray Instruments, Madison, WI, (1995).Google Scholar
11. Fleming, B. A. and Crerar, D. A., Geothermics, 11, 15 (1986).Google Scholar
12. Koningsveld, H. van, Bekkum, H.van and Jansen, J., Acta Cryst. B, 43, 127 (1987).Google Scholar