Synthesis and Characterization of Small-Crystal Size Zeolite NaY
Wenwen Fu, Jihong Sun*
College of Enviromental & Energy Engineering, Beijing University of Technology, Beijing, 100124, P. R. China
*Corresponding author, E-mail: jhsun@bjut.edu.cn, Fax: 86-10-67391983
Introduction
Studies of composite zeolite are very active subject in petroleum refining processes and have received much
attention in recent years [1]. In this report, a novel procedure for the preparation of bi-microporous composite
zeoliteβ/Y was being developted in the hydrothermal system by using high silica NaY as precursor in our
laboratory, whereas the key work was how to synthesize nanometer Y gel successfully. Meantime, the effects of
reaction conditions such as reaction temperature, reaction time and reactant ratio on the composite structure was
investigated.
Results and Discussion
(111)
(111)
(220) (311) (331)
(440)
(533) (642)
(533) (642)
(751)
(220)(311)
(331)
(440)
(751)
Figure 1 XRD patterns of NaY zeolite crystallized
Figure 2 XRD patterns of NaY zeolite crystallized
with different time. a-4h, b-8h, c-12h, d-24h
with different temperature. a-90℃, b-100℃, c-110℃
NaY zeolite was prepared in hydrothermal conditions in which directing agent was prepared according to
the report [2]. Finally, the typical composition of NaY zeolite is following that: Na2O : Al2O3 : SiO2 : H2O =
8:1:10:220. The XRD patterns of NaY zeolite crystallized with different time are given in Figure 1. As can be
seen, the results showed that NaY zeolite was prepared with a rather wide range of reaction time from 4 hrs to
36 hrs. When crystallizing with 8 hours, the characteristic peaks (111, 220, 311, 331, 440, 533, 642 and 751) of
NaY zeolite was more obvious than that of 4 hours, and their related diffraction intensity was up to the largest.
However, with increasing crystallization time (more 12 hrs), the diffraction intensity of thses characteristic
peaks was decreased. Figure 2 illustrates the influence of crystallization temperature on the structure of NaY
zeolite. The results show that the optimal crystallization temperature of varying between 90℃ to 110℃ was
around 100℃ in Figure 2b, which was of the best crystal degree, and corresponding to the uniform particle size
with around 150 nm by means of SEM image (not shown). The influence of various reaction parameters are
being done. The structure and the synthesis mechanism are further investigated using HRTEM and
MAS-NMR.
References
[1] L. Xu, H. Xu, T. Wu, J. Catalysis, 2006, 27(12): 1149-1158.
[2] R. Xu, W. Pang, Chenmistry Zeolite and Porous Materials [M], Science Press, 2004
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Si