Synthesis method of MFI molecular sieve nanosheet

A synthesis method and technology of nanosheets, applied in the direction of molecular sieve characteristic polycrystalline silicon, nanotechnology, silicon compounds, etc., can solve problems such as limiting application prospects, corroding devices, environmental pollution, etc., and achieve simple material types and good parallelism Sexuality and the effect of reducing production costs

Pending Publication Date: 2021-04-09
NANKAI UNIV
View PDF9 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

As we all know, because fluoride itself is very toxic and corrosive, it will not only corrode the device, but also pollute the environment, causing serious environmental pollution and safety problems, thus greatly limiting the application prospects of this method

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Synthesis method of MFI molecular sieve nanosheet
  • Synthesis method of MFI molecular sieve nanosheet
  • Synthesis method of MFI molecular sieve nanosheet

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0040] The invention provides a kind of synthetic method of MFI molecular sieve nanosheet, and its concrete steps are:

[0041] Step 1, the material ratio of the raw materials required for the synthesized MFI molecular sieve nanosheets is: SiO 2 :xAl 2 o 3 :yR:mH 2 O, wherein: R is a templating agent, 0

[0042] Step 2. Weigh the required amount of template agent R, silicon source and a certain amount of water and stir evenly to form a synthetic sol.

[0043] Step 3, adding an aluminum source to the above-mentioned synthetic sol, and stirring evenly;

[0044] Step 4. Add a fluorine-free acid reagent to the above synthetic sol, adjust the pH value of the system to 7.0-9.5, and stir and pre-crystallize at 40-100°C for 1-50 hours to obtain a synthetic mother liquor; the acid reagent can be Inorganic acids such as sulfuric acid and hydrochloric acid may also...

Embodiment 1

[0059] Synthetic ratio: SiO 2 :Al 2 o 3 :R:H 2 O=1:0.01:0.15:25, wherein R is tetrapropylammonium hydroxide.

[0060] Synthesis steps: drop tetrapropylammonium hydroxide and ethyl orthosilicate into water respectively, mix and stir for 4 hours, then add pseudo-boehmite, use H 2 SO 4 Adjust the pH value of the system to about 8.5, uniformly stir and pre-crystallize at 90°C for 12 hours, then put it into a polytetrafluoroethylene-lined reactor, crystallize at 95°C for 4 days, and cool to room temperature. The resulting mixture is subjected to solid-liquid separation and washing. The solid phase product was dried at 80°C to obtain the final product.

[0061] figure 1 is the XRD spectrum of the obtained product, it can be seen that the product has typical characteristic diffraction peaks of the MFI structure, and the crystallinity is relatively high. figure 2 It is the SEM photo of the obtained product, it can be seen that the product is in the shape of a sheet, with a thi...

Embodiment 2

[0063] Synthesize MFI molecular sieve nanosheets according to the raw materials and steps in Example 1, the difference is that the synthesis ratio is: SiO 2 :R:H 2 O=1:0.15:25; that is, no aluminum source is added during the synthesis process. After the synthetic mother liquor was put into the reactor, it was crystallized at 90°C for 4 days, and the resulting mixture was separated from solid and liquid and dried to obtain the final solid phase product.

[0064] image 3 is the XRD spectrum of the resulting product, as can be seen, the product is a molecular sieve with MFI structure; Figure 4 The SEM photo of the obtained sample shows that the sample is a MFI molecular sieve nanosheet with a thickness of about 50-80 nm and a length of about 1.0 μm. , about 0.2µm in width

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
thicknessaaaaaaaaaa
thicknessaaaaaaaaaa
thicknessaaaaaaaaaa
Login to view more

Abstract

The invention discloses a synthesis method of an MFI molecular sieve nanosheet. The method takes a small amount of template agent, silicon source and aluminum source as raw materials for hydrothermal synthesis, and is characterized by comprising the following steps: firstly, uniformly stirring the template agent, the silicon source and a certain amount of water, then selectively adding the aluminum source, adjusting the pH value of the system, stirring and pre-crystallizing for 1-50 hours at 40-100 DEG C, and then crystallizing for 1-10 days at 80-150 DEG C; and after the crystallization is finished, cooling the reaction kettle to room temperature, and then carrying out suction filtration/centrifugation, washing and drying on the product. According to the method, the synthesis temperature is low, the synthesis pressure is low, a fluorine-containing reagent does not need to be used, the yield exceeds 80%, and the thickness of the nanosheet can be regulated and controlled through the pH value of the system and the dosage of a template agent. The synthesized MFI molecular sieve nanosheet is high in crystallinity and controllable in thickness, more synthesis energy consumption is saved under the low-temperature and low-pressure conditions, industrial scale-up production is facilitated, and the MFI molecular sieve nanosheet has a good industrial popularization prospect.

Description

technical field [0001] The invention belongs to the technical field of synthesis of zeolite molecular sieves, in particular to a method for synthesizing MFI molecular sieve nanosheets. Background technique [0002] MFI molecular sieve is one of the most important molecular sieve catalytic materials because of its well-developed pore structure, good thermal stability, suitable adjustable acid center density and excellent shape-selective catalysis, and its typical representative is ZSM-5. Molecular sieve. However, due to the small pore size of MFI, it not only increases the diffusion resistance of reactant molecules in its pores to a certain extent, which causes catalyst deactivation, but also limits the application of this material in catalytic reactions. At present, compared with MFI zeolites with other shapes, MFI molecular sieve nanosheets show good separation and penetration performance and excellent anti-carbon deposition ability. Therefore, research on MFI molecular s...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C01B39/40C01B37/02B82Y40/00
CPCC01B39/40C01B37/02B82Y40/00C01P2004/24C01P2004/61C01P2004/62C01P2004/64
Inventor 武光军邰文姝代卫炯戴卫理关乃佳李兰冬
Owner NANKAI UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap