Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Molecular sieve acidity and pore structure composite modulation method

A technology of molecular sieve and pore structure, which is applied in the direction of molecular sieve catalysts, chemical instruments and methods, silicates, etc., can solve the problems of molecular sieve dissolution and microporous structure damage, loss of strong acid centers of molecular sieves, and raising the treatment temperature of soda ash solution, etc., to achieve The microporous structure is well maintained, the center density is increased, and the center density is complete.

Inactive Publication Date: 2017-06-09
DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
View PDF5 Cites 7 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Javier Pérez-Ramírez et al. also investigated the pore structure changes of pure silicon MFI molecular sieves (Si / Al=∞) in NaOH solution (Chem.Eur.J.2011,17,1137-1147), and found that adding A small amount of metal (Al 3+ , Ga 3+ ) salts, which can avoid the disorder and massive dissolution of pure silicon MFI molecular sieves, but this treatment method cannot generate strong acid centers in the molecular sieves
The characteristics of the alkali treatment method in the above-mentioned molecular sieve post-treatment method are: due to the four-coordinated skeleton Al (strong acid site) structure removal effect, so that the strong acid center of the molecular sieve suffers a certain loss after treatment; in addition, the adjustment of the secondary pore structure of the molecular sieve depends entirely on the temperature (60-90 °C) and concentration ( 0.2-5.0 mol / liter), but simply increasing the treatment temperature of pure lye and the concentration of lye will cause the secondary pore diameter to become larger, and the high-concentration alkaline solution will easily lead to a large amount of dissolution of molecular sieves and destruction of microporous structure ( Chem.Eur.J.2005,11,4983-4994)
The above shortcomings make the structure obtained by the above alkaline treatment method obtain a certain modulation, but the number of strong acid centers in the acidic molecular sieve is weakened to a certain extent, so that its application is limited

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
  • Molecular sieve acidity and pore structure composite modulation method
  • Molecular sieve acidity and pore structure composite modulation method
  • Molecular sieve acidity and pore structure composite modulation method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Take 10g ZSM-5 molecular sieve (Si / Al=35, Na 2 O content 3 ) 3 In the solution, magnetically stirred at 65°C for 35 minutes, then filtered and washed to neutrality, dried at 120°C for 12 hours, and calcined in a muffle furnace at 550°C for 3 hours. The obtained molecular sieve was added to 0.8mol / L ammonium nitrate solution, solid-liquid ratio was 1:10, magnetically stirred at 85°C for 2 hours, then filtered and washed, dried at 120°C for 12 hours, and then placed in a muffle furnace It is calcined at 550°C for 6 hours. Table 1 shows the structure data of molecular sieve treated with aluminum-containing compound alkaline medium. In this example, the secondary pore distribution curve of the ZSM-5 molecular sieve sample treated with aluminum-containing alkaline medium is as follows figure 1 Shown.

Embodiment 2

[0027] Take 15g ZSM-5 molecular sieve (Si / Al=38, Na 2 O content 0.15wt%) added to 200ml containing 0.25mol / L KOH-0.005mol / L AlF 3 In the mixed solution, magnetically stirred at 65°C for 60 minutes, then filtered and washed to neutrality, dried at 110°C for 12 hours, and calcined in a muffle furnace at 540°C for 3 hours. The obtained molecular sieve was added to 1.0mol / L ammonium nitrate solution with a solid-to-liquid ratio of 1:20, magnetically stirred at 85°C for 2 hours, then filtered and washed, dried at 120°C for 12h, and then placed in a muffle furnace for 550 Calcined at ℃ for 6 hours, denoted as B. Table 1 shows the structure data of molecular sieve treated with aluminum-containing compound alkaline medium. The secondary pore distribution curve of the sample after ZSM-5 molecular sieve treatment with aluminum-containing alkaline medium in this example is as follows: figure 2 Shown.

Embodiment 3

[0029] Take 10g ZSM-5 molecular sieve (Si / Al=34, Na 2 O content 0.15wt%) was added to 200ml mixed solution containing 0.25mol / L NaOH-0.009mol / L aluminum isopropoxide, stirred magnetically at 75°C for 55 minutes, then filtered and washed to neutrality, dried at 110°C for 12 hours Firing in a muffle furnace at 540°C for 3 hours. The obtained molecular sieve was added to 1.0mol / L ammonium nitrate solution with a solid-to-liquid ratio of 1:20, magnetically stirred at 85°C for 2 hours, then filtered and washed, dried at 120°C for 12h, and then placed in a muffle furnace for 550 Calcined at ℃ for 6 hours, denoted as C. Table 1 shows the structure data of molecular sieve treated with aluminum-containing compound alkaline medium.

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

No PUM Login to View More

Abstract

The invention provides a molecular sieve acidity and pore structure composite modulation method, belonging to the fields of molecular sieve modification, adsorbing material preparation and catalyst preparation. The method comprises the following steps: introducing an aluminum salt into a high-silicon molecular sieve or treatment medium in a certain mode, carrying out heating treatment, carrying out filtration washing to neutrality, drying, and carrying out ion exchange and roasting process exchange to obtain the hydrogen-type molecular sieve. The method is simple to operate and low in cost, and can effectively enhance the product yield of the modified molecular sieve material. The obtained modified molecular sieve material remains the good micropore structure, and generates the abundant secondary pore structure; and the acidity has the following distribution characteristics: the strong acid central density is completely kept, and the weak acid and medium acid central densities are enhanced.

Description

Technical field [0001] The invention belongs to the fields of molecular sieve modification, adsorption material preparation and catalyst preparation, and specifically relates to a compound adjustment method of molecular sieve acidity and pore structure. Background technique [0002] Since the advent of molecular sieve, due to its rich microporous structure, good hydrothermal stability and strong acidity, it has been widely used in the catalytic fields of petroleum processing, coal chemical industry, environmental protection and fine chemical industry as a catalysis, adsorption and separation material. In particular, molecular sieves such as ZSM-5 and mordenite have been widely used in cracking, isomerization, alkylation, aromatization and other reactions. Due to the small pore size of the microporous molecular sieve, there are problems such as adsorption, diffusion limitation, and easy carbon deposition in the reaction. Improving its pore structure and acid property distribution ...

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): B01J20/16B01J20/30B01J29/40
Inventor 黄声骏杨识途刘珍妮陈福存谢素娟徐龙伢
Owner DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com