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Study on Synthesis, Characterization and Catalytic Behavior of Novel Hetero-atom β Zeolite

Author: XiaoZhiWen
Tutor: HeHongYun
School: Hunan Normal University
Course: Inorganic Chemistry
Keywords: Zeolite Fe-V-β zeolite Cu-β zeolite Hydrothermal Synthesis Directing agent law Catalytic
CLC: O643.36
Type: Master's thesis
Year: 2010
Downloads: 81
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Abstract

Zeolite β is a high silicon, high thermal stability and hydrothermal stability, and having a three-dimensional 12-membered ring zeolitic molecular sieve of the macroporous structure of concern in recent years, in the green area of ??the catalytic material. Hetero atoms and the introduction of β zeolite skeleton allows it to exhibit excellent physical and chemical characteristics and unique catalytic performance, especially having a hetero atom obtained by the specific catalytic properties of the transition metal atom isomorphous substitution of part of the silicon or the framework aluminum β-zeolite, since the transition metal atoms in the zeolite framework in a highly dispersed state, so that they have a general transition metal oxides are not the catalytic redox function. Therefore, the study of new heteroatom p zeolite has both theoretical significance, but also has practical value. By hydrothermal crystallization method this paper, we first synthesized double heteroatom Fe-V-β the zeolite and single hetero atom Cu-β zeolite, the Cu-β zeolite was synthesized by directing agent, and discusses the factors affecting the synthesis of zeolite , and the initial effects of their catalytic properties. Details are as follows: 1.Fe-V-beta zeolite synthesis, characterization and catalytic properties of hydrothermal synthesis in SiO2-Fe2O3-V2O5-(TEA) 2O-H2O-NH4F system Fe-V-β zeolite synthesis the use of X-ray diffraction, infrared spectroscopy, solid diffuse reflectance spectroscopy, thermogravimetry - differential thermal analysis, scanning electron microscopy - energy dispersive spectroscopy and plasma emission spectrometer testing techniques to characterize the structure and chemical composition of the samples, and to explore the impact of Fe- V-β zeolite synthesis factors. The results showed that the preparation of the initial reaction mixture by the following chemical composition: n (SiO2): n (Fe2O3): n (V2O5): n [(TEA) 2O]: n (H2O): n (NH4F) = 60: (0.1 ~ 0.75): (0.1 to 0.75): (17 ~ 18): (550 to 650): (30 ~ 50), can be prepared Fe-V-β zeolite, the crystallinity is good, and Fe and V atoms into the zeolite framework . The synthesis of Fe-V-β zeolite shows good catalytic activity in the reaction of styrene oxide with H2O2 as oxidant, the conversion of styrene was 25.4%. Product selectivity: 69.1% of benzaldehyde, phenylacetaldehyde 22.5%, 4.1% acetophenone. Zeolite synthesis, characterization, and catalytic properties of 2.Cu-β research in the SiO2-CuO-(TEA) 2O-H2O-NH4F system hydrothermal crystallization synthesis of zeolite, the use of Cu-β XRD, IR, UV-Vis solid diffuse reflectance spectroscopy, TG / DTA, SEM and ICP, test techniques to characterize the physical and chemical characteristics of the samples, and to explore the influencing factors of synthetic Cu-β zeolite. The results showed that the preparation of the initial reaction mixture by the following chemical composition: n (SiO2): n (CuO): N [(TEA) 2O]: n (H2O): n (NH4F) = 60: (of 0.5 ~~ 5.0): ( 16 ~ 18): (550 ~ 650): (25β50), can be prepared by the Cu-β zeolite, the crystallinity is good, and the Cu atoms into the zeolite framework. H2O2 as the oxidant in phenol hydroxylation reaction, Cu-β zeolite showed better catalytic activity. The synthesis directing agent Cu-zeolite beta synthesized by directing agent Cu-β zeolite, and the XRD, FT-IR, UV-Vis, SEM and TG / DTA method for the synthesis of Cu-zeolite beta characterization. Because the method is only added when the directing agent was prepared organic templating agent is tetraethyl ammonium hydroxide (TEAOH), and in the synthesis of Cu-β zeolite to add only a small amount of directing agent, without further TEAOH template method of synthesis of Cu-β zeolite compared to the amount of organic templating agent TEAOH greatly reduced, greatly reducing the cost of synthesis of the Cu-β zeolite.

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