Synthesis of Nanosized NaY Molecular Sieve under Dynamic Hydrothermal Crystallization

Abstract:

Nanosized NaY molecular sieves with high crystallinity was synthesized using sodium silicate solution (industrial water glass) without the presence of additive via dynamic hydrothermal method. The influences of aging time of the seed-gel, the temperature and route of gelation, and the alkalinity of the feed-stock gel on the grain size, relative crystallinity and framework SiO₂/Al₂O₃ ratios of NaY nanoparticles were investigated by XRD(X-ray diffraction, XRD), SEM(Scanning electron microscope, SEM) and TEM(Transmission electron microscope, TEM). The results shown that the grain size could be effectively controlled by adding seed-gel of aging at 20°C for 4 days, and adopting the gelation route of putting sodium silicate solution into NaAlO₂ and NaOH mixed solution. The grain size and framework SiO₂/Al₂O₃ ratios decreased with reducing the alkalinity of synthetic system. The nanoNaY products with the grain size at a range of 82-105 nm and the framework SiO₂/Al₂O₃ ratios at 3.9-4.0 could be synthesized by optimizing the synthesis conditions.

• Periodical: Key Engineering Materials (Volumes 609-610)
• Pages: 288-297
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.609-610.288
• Online since: April 2014
• Authors: Ying Chen*, Peng Liu, Zhi Wu Yu, Juan Tan
• Keywords: Alkalinity, Dynamic Hydrothermal Method, Framework SiO₂/Al₂O₃ Ratios, Nanosized NaY Zeolite, Seed-Gel

References

[1] Camblor MA, Corma A, Valencia S. Characterization of nanocrystalline zeolite beta. Microporous Mesoporous Mater 1998; 25: 59-74.

DOI: 10.1016/s1387-1811(98)00172-3

[2] Huang LM, Wang ZB, Wang HT, et al. Hierarchical porous structures by using zeolite nanocrystals as building blocks. Microporous Mesoporous Mater 2001; 48: 73-78.

DOI: 10.1016/s1387-1811(01)00332-8

[3] Camblor MA, Corma A, Martinez A, et al. Catalytic cracking of gasoil-Benefits inactivity and selectivity of small Y zeolite crystallites stabilized by a higher silicon-to-aluminium ratio by synthesis. Appl Catal 1989; 55: 65-74.

[4] Taufiqurrahmi N, Mohamed AR, Bhatia S. Nanocrystalline zeolite beta and zeolite Y as catalysts in used palm oil cracking for the production of biofuel. J Nanopart Res 2011; 13: 3177-3189.

DOI: 10.1007/s11051-010-0216-8

[5] Wang HT, Holmberg BA, Yan YS. Homogeneous polymer-zeolite nanocomposite membranes by incorporation dispersible template-removed zeolite nanocrystals. Mater Chem 2002; 12: 3640-3643.

DOI: 10.1039/b207394c

[6] Ma YL, Chen SY, Peng SY. Peparation and characterization of clear liquid phase initiating agent for synthesis of small particle size NaY zeolite. Chin J Catal 1995; 16: 410-414.

[7] William JA. Microcrystalline synthetic faujasite. Patent 4372931, USA, (1983).

[8] Macher PK, Scherzer J. Method of preparing micro crystalline faujasite-type zeolite. Patent 3516786, USA, (1970).

[9] Li QH, Creaser D, Sterte J. An Investigation of the nucleation/crystallization kinetics of nanosized colloidal faujasite. Chem Mater 2002; 14: 1319-1324.

DOI: 10.1021/cm011242g

[10] Tang K, Wang YG, Song LJ, et al. Caron nanotube templated growth of nano-crystalline ZSM-5 and NaY zeolite. Mater Let 2006; 60: 2158-2160.

DOI: 10.1016/j.matlet.2005.12.088

[11] Sohn JR, DeCanio SJ, Lunsford JH, et a1. Determination of framework aluminum content in delaminated Y-type zeolite: a comparison based on unit cell size and wavenumber of i. r. hend. Zeolit 1986; 6: 225-227.

DOI: 10.1016/0144-2449(86)90054-0

[12] Francesco Di Renzo, Zeolites as tailor-made catalysis: Control of the crystal size. Catal Today 1998; 41: 37-40.

DOI: 10.1016/s0920-5861(98)00036-4

[13] Ma YL, Chen SY, Peng SY, et al. Kinetic study on zeolite nucleation and crystal growth Ⅰ. Modified Lechert model in the system of non-spontaneous nucleation. Acta Petro Sin 1997; 13: 47-54.

[14] Gonthier S, Thompson RW. Sol-gel chemistry and molecular sieve synthesis. Stud Surf Sci Catal 1994; 85: 13.

[15] Tosheva L, Valtchev V. Nanozeolites: Synthesis, crystallization mechanism, and appliations. Chem Mater 2005; 17: 2494-2513.

DOI: 10.1021/cm047908z

[16] Adnadjevic B, Vukicevic J, Filipovic RZ, et al. The influence of NaX zeolite particle size on crystallinity measured by the XRD method. Zeolit 1990; 10: 699-702.

DOI: 10.1016/0144-2449(90)90083-4

[17] Kim YC, Jeong JY. Influencing factors on rapid crystallization of high silica nano-sized zeolite Y without organic template under atmospheric pressure. J Porous Mater 2009; 16: 299-306.

DOI: 10.1007/s10934-008-9200-4