HYDROTHERMALLY GROWN ZEOLITE CRYSTALS
Abstract
The aluminium-deficient and ferrosilicate zeolite-type materials were synthesized by hydrothermal process at 150-170oC for various periods of time from the mixtures containing colloidal reactive silica, sodium aluminate, sodium hydroxide, iron nitrate and organic templates. Organic polycation templates were used as zeolite crystal shape modifiers to enhance relative growth rates. The template was almost completely removed from the zeolite specimens by calcination at 550 oC for 8h in air. Simultaneous thermogravimetric (TG) and differential thermal analysis (DTA) was performed to study the removal of water molecules and the amount of organic template cations occluded inside the crystal pore of zeolite framework. The ~12-13% weight loss in the range of (140-560oC) was associated with removal of the (C3H7)4N+ cation and water molecules. X-ray diffraction (XRD) analysis and scanning electron microscope (SEM) techniques were employed to study the structure, morphology and surface features of hydrothermally grown aluminium-deficient and ferrosilicate zeolite-type crystals. In order to elucidate the mode of zeolite crystallization the crystallinity and unit cell parameters of the materials were determined by XRD, which are the function of Al and Fe contents of zeolites.References
J., Karge, H. G., Pfeifer, H., Holderich, W., Eds. Zeolites and Related Microporous Materials: State of the Art, Weitkamp, Elsevier Amsterdam, (1994).
M. M.J. Treacy, B. K. Marcus, M. E. Bisher and J.B. Higgins, Eds., Materials Research Society: Warrendale, PA, (1999).
Sh. Sang, F. Chang, Zh. Liu, Ch. He, Y. He and L. Xu, Catal. Today 93 (2004) 729.
L. Shirazi, E. Jamshidi and M. R. Ghasemi, Cryst. Res. Technol. 43 (2008) 1300.
R. Szostak, Handbook of Molecular Sieves; Van Nostrand: New York, (1992).
R. M. Mohamed, H. M. Aly, M. F. El-Shahat, I.A. Ibrahim, Microporous and Mesoporous Materials 79 (2005) 7.
P. Pookmanee, G. Rujijanagul, S. Ananta, R.B. Heimann and S. Phanichphant, J. Eur. Ceram. Soc. 24 (2004) 517.
M. P. Roxana, Nanotechnology 14 (2003) 312.
M. Zhang, Z. S. Jin, J. J. Yung and Z. J. Zhang, J. Molec. Catal. A: Chem. 217 (2004) 203.
C.E.A , Kirschock, R. Ravishankar, P. A. Jacobs and J. Martens, J. Phys. Chem. B 103 (1999) 11021
D.P. Serrano and S. Van Grieken, J. Mater. Chem. 11 (2001) 2391.
O. Terasaki, T. Ohsuna, Z. Liu, Y. Sakamoto and A.E. Garcia-Bennett, Studies in Surface Science and Catalysis, 148 (Mesoporous Crystals and Related Nano-Structured Materials), ( 2004) 261.
Y. Sasaki and H. Kato, Zeoraito 21 (2004) 1.
L. D. Rollmann, “Synthesis of zeolites, an overview, Zeolites: Science and Technologyâ€, Martinus Nijhoff Publishers, Hague, (1984) p. 109.
M. Patal and A. Karera , J. Mater. Sci. Lett. 8 (1989) 955
H.H. Willard ,L.L.Jr. Merrit, J.A. Dean and F.A. Jr. Settle, Instrumental methods of analysis, 7th Ed., Wadsworth Publishing Company, USA, (1988).
J. W. Visser, J. Appl. Crystallogr. 2 (1969) 89
JCPDS No.42-0022 (2002), International Centre for diffraction data.
American Society for Testing and Materials (ASTM), Annual Book of ASTM Standards, Section 15.02 C169-80, (1987).
R.H. von Ballmoos, J. Collection of Simulated XRD powder pattern for Zeolites 10 (1990) 4365
A.I. Vogel, Text book of quantitative chemical analysis, G.H. Jeffery, J. Bassett, J. Mendham and R.C. Denney (Eds.), Longman Scientific and Technical Ltd., Essex-England, (1989).
A. Erdem and L.B. Sand, In Proc. 5thInt. on Zeolite Conf., ed. J.V.C. Rees. Heyden, London, (1980).
P.A. Jacobs and J.A. Martens, Stud. Surf. Sci. Catal. 33 (1987) 71.
G.T. Kokotailo, P.Chu and S.L. Lawton, Nature 275 (1978) 199.
S. K. Durrani, N. A. Chughtai, J. Akhtar, K. Saeed, M. Arif and M. Ahmed, The Nucleus 37 (2000) 35.
D.T.Hayhurst, A.Nastro, R.Aiello, F.Crea and G. Giordano, Zeolites 8 (1989)416
D. Zhao, Sh. Qiu and W. Pang, Zeolites 13 (1993) 478.
S. K. Durrani, J. Akhtar, N. A. Chughtai, M. Ahmad and M.J. Moughal, J. Mat. Sci. Tech. 21, Nos. 4 (2005) 563.
N. Kumar, V. Nieminen, K. Demirkan, T. Salmi, D. Y. Murzin and E. Laine, Appl. Catal. A 235, (2002) 113.
Hydrothermally
