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Preparation method and application of thin-layer nanosheet type hierarchical pore TS-1 molecular sieve catalyst

A TS-1, nanosheet technology, applied in molecular sieve catalysts, molecular sieves and base exchange compounds, chemical instruments and methods, etc., can solve the problems of enhancing the diffusion rate within the catalyst, easy deactivation of the catalyst, low activity, etc. Generation of ring by-products, increased selectivity, and reduced effect of surface acid sites

Active Publication Date: 2021-02-26
JIANGSU YANGNONG CHEM GROUP +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003]Aiming at the problems of traditional TS-1 molecular sieves such as diffusion limitation, catalyst deactivation and low activity, the present invention builds a core-shell structure multi-level porous thin-layer nano The sheet-type Silicalite-1@TS-1 catalyst, on the one hand, can eliminate the internal diffusion limitation and greatly enhance the internal diffusion rate of the catalyst; in addition, by suppressing the surface acidity of the catalyst, the service life of the catalyst can be greatly extended and the stability of the catalyst can be improved

Method used

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  • Preparation method and application of thin-layer nanosheet type hierarchical pore TS-1 molecular sieve catalyst
  • Preparation method and application of thin-layer nanosheet type hierarchical pore TS-1 molecular sieve catalyst
  • Preparation method and application of thin-layer nanosheet type hierarchical pore TS-1 molecular sieve catalyst

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] 45.0g ethyl tetrasilicate (0.2mol, TEOS) and 56.0g 25wt.% tetrapropylammonium hydroxide (0.068mol, TPAOH) mixed hydrolyzate were stirred for 30min until a transparent sol was formed. Hydrolyze for 1h, add 4.25g quaternary ammonium salt template I (0.005mol, Template-I) to obtain orthosilicic acid, ethyl ester hydrolyzate; after cooling to 0°C, continue to slowly add 18wt.% containing 4.4g tetrabutyl titanate (0.013mol, TBOT) and 19.8g of isopropanol (0.33mol, IPA) solution, after the dropwise addition, continue to heat up to 85°C and hydrolyze for 4h, the composition of the pre-hydrolyzed sol is 1SiO 2 : 0.34TPAOH: 1.65IPA: 0.065TBT: 20H 2 O: 0.023 template-I. After the pre-hydrolysis, transfer to 180°C tetrafluorohydrothermal kettle for hydrothermal crystallization for 48 hours to obtain TS-1 nanosheets. Cool to room temperature, centrifuge, wash and dry to obtain titanium silicon molecular sieve seed crystals, continue to add 4.16g (0.02mol) TEOS and 5.69g (0.007mol...

Embodiment 2

[0025]Vigorously stir the mixed solution of 45.0g ethyl orthosilicate (0.2mol, TEOS) and 56.0g 25wt.% tetrapropylammonium hydroxide (0.068mol, TPAOH) for 30min until a transparent sol is formed, and pre-hydrolyze at 85°C under normal pressure 1h, then add 3.78g of quaternary ammonium salt template II (0.005mol, template-II) to obtain ethyl orthosilicate hydrolyzate; after cooling to 0°C, continue to slowly add 18wt.% containing 4.4g tetrabutyl titanate ( 0.013mol, TBT) and 19.8g isopropanol (0.33mol, IPA) solution, after the dropwise addition, continue to heat up to 65°C to continue hydrolysis for 4h, the molar ratio of the pre-hydrolyzed sol is 1SiO 2 : 0.34TPAOH: 1.65IPA: 0.065TBT: 20H 2 O: 0.023 template-II. After the pre-hydrolysis, transfer to 180°C PTFE internal hydrothermal kettle for hydrothermal crystallization for 96 hours to obtain TS-1 nanosheets. Cool to room temperature, centrifuge, wash to obtain titanium silicon molecular sieve seed crystals, continue to add ...

Embodiment 3

[0027] Stir the mixture of 45.0g tetraethyl orthosilicate (0.2mol, TEOS) and 56.0g 25wt.% tetrapropylammonium hydroxide (0.068mol, TPAOH) vigorously for 30min until a transparent sol is formed. After hydrolysis for 1 h, 3.26 g of quaternary ammonium salt template III (0.005 mol, Template-III) was added to obtain tetrabutyl orthosilicate hydrolyzate; after cooling to 0° C., 18 wt.% containing 4.4 g of tetrabutyl titanate ( 0.013mol, TBT) and 19.8g isopropanol (0.33mol, IPA) solution, heated to 55°C and continued hydrolysis for 4h, the molar ratio of the pre-hydrolyzed sol was 1SiO 2 :0.325TPAOH:1.56IPA:0.06TBT:20H 2 O: 0.023 Template-III. After the pre-hydrolysis, transfer to 180°C PTFE internal hydrothermal kettle for hydrothermal crystallization for 48 hours to obtain TS-1 nanosheets. Cool to room temperature, centrifuge, wash to obtain titanium silicon molecular sieve seed crystals, continue to add 4.16g TEOS (0.02mol) and 5.69g (0.007mol, 25wt.%) TPAOH and 81.24g H 2 The...

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Abstract

The invention provides a preparation method and application of a thin-layer nanosheet type hierarchical pore TS-1 molecular sieve catalyst with high stability and high activity. The TS-1 catalyst corelayer is a nanosheet type hierarchical pore TS-1 molecular sieve, and the catalyst shell layer is a pure silicon molecular sieve Silicalite-1. Through construction of the hierarchical pore TS-1 nanosheet type molecular sieve catalyst, the problem of internal diffusion limitation existing in pore channels of a traditional granular titanium silicalite molecular sieve can be eliminated, and throughsurface construction of a pure silicon molecular sieve Silicalite-1 shell layer, the surface acidity of a conventional TS-1 molecular sieve can be reduced, and generation of ring-opening byproducts isinhibited. The catalyst can be applied to a reaction for synthesizing epichlorohydrin by a chloropropene hydrogen peroxide method, the selectivity of epichlorohydrin can be effectively improved, andthe service life of the catalyst can be effectively prolonged.

Description

technical field [0001] The invention provides a method for synthesizing epichlorohydrin with a highly stable and highly active nanosheet core-shell structure catalyst Silicalite-1@TS-1. The catalyst core layer is TS-1 with a nanosheet structure, and the catalyst shell layer is It is a pure silicon molecular sieve Silicalite-1, through the construction of pure silicon molecular sieve Silicalite-1, the acid sites on the surface of the molecular sieve can be reduced, and the generation of ring-opening by-products can be suppressed. Improve catalyst stability. The catalyst can be applied to the epoxidation of halogenated olefins, especially the synthesis of epichlorohydrin by the chloropropene hydrogen peroxide method, can effectively improve the selectivity of epichlorohydrin and the service life of the catalyst, and belongs to the refined field. Background technique [0002] Epichlorohydrin is an important organic chemical raw material and fine chemical product. The epoxy res...

Claims

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Application Information

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IPC IPC(8): C01B39/08B01J29/40B01J35/10
CPCC01B39/085B01J29/405C01P2004/04C01P2004/24B01J35/60Y02P20/52
Inventor 徐林邓生财黄杰军丁克鸿胡金良
Owner JIANGSU YANGNONG CHEM GROUP