CN114014334A - Medium silicon-aluminum ratio ZSM-5 heterozygous nanosheet molecular sieve and preparation method thereof - Google Patents

Medium silicon-aluminum ratio ZSM-5 heterozygous nanosheet molecular sieve and preparation method thereof Download PDF

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CN114014334A
CN114014334A CN202111394714.1A CN202111394714A CN114014334A CN 114014334 A CN114014334 A CN 114014334A CN 202111394714 A CN202111394714 A CN 202111394714A CN 114014334 A CN114014334 A CN 114014334A
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molecular sieve
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程党国
郝靓
陈丰秋
詹晓力
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Zhejiang University ZJU
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Abstract

The invention discloses a medium-silica-alumina-ratio ZSM-5 heterozygous nanosheet molecular sieve and a preparation method thereof, and belongs to the technical field of catalysts. The hybrid molecular sieve consists of an internal microporous substrate and a nano-sheet layer epitaxially grown outside the microporous substrate, the silicon-aluminum ratio range of the hybrid molecular sieve is adjustable within the range of 100-300, and the preparation method specifically comprises the following steps: 1) dissolving a small molecular template agent, a silicon source and an aluminum source in water, and uniformly stirring to form gel; 2) aging under stirring; 3) continuously adding the long carbon chain amphiphilic surfactant solution and uniformly stirring; 4) aging under stirring; 5) and crystallizing to obtain the hybrid ZSM-5 molecular sieve. The preparation method solves the problem that the synthesis of the nano sheet-block hybrid molecular sieve silicon-aluminum ratio at the present stage limits the shape of the molecular sieve, breaks through the limitation that the growth of the outer nano sheet cannot be maintained when the silicon-aluminum ratio is reduced, and the prepared hybrid molecular sieve has great application prospect in the catalytic field of preparing low-carbon olefin and the like.

Description

Medium silicon-aluminum ratio ZSM-5 heterozygous nanosheet molecular sieve and preparation method thereof
Technical Field
The invention belongs to the field of catalysts, and particularly relates to a medium-silica-alumina-ratio ZSM-5 hybrid nanosheet molecular sieve and a preparation method thereof.
Background
The hierarchical pore molecular sieve combines the acid catalysis performance of the microporous molecular sieve and the diffusion and mass transfer characteristics of medium pores or large pores, and the introduction of the mesopores improves the coking resistance of the traditional microporous catalyst, so that the hierarchical pore molecular sieve has wide application prospects in the chemical industry. The key point for synthesizing the hierarchical pore molecular sieve with good catalytic performance lies in the balance between the acid catalytic function and the mesoporous size.
The existing methods for synthesizing the hierarchical pore molecular sieve are mainly divided into a post-treatment method and an in-situ synthesis method. The nanosheet type ZSM-5 molecular sieve synthesized in situ by using the long-carbon-chain quaternary ammonium salt surfactant is the key point for researching the multi-stage pore MFI molecular sieve at present, and an ultrathin framework in the b-axis direction provides an open and interconnected mesoporous structure, so that the two-dimensional molecular sieve has good catalytic stability. However, further research finds that the discontinuous framework of the nano-sheet molecular sieve along the b-axis direction can generate a large amount of Al outside the framework and Si-OH outside the framework, so that deep reaction of products is caused, and the catalytic performance is influenced.
The excellent diffusion performance of the nano-sheet molecular sieve is maintained, and the improvement of the micropore proportion and the adjustment of the acid distribution on the outer surface are of great importance for improving the catalytic performance of the nano-sheet molecular sieve. The double-template method is used for synthesizing the hybrid molecular sieve with the nanosheet layer epitaxially grown outside the block-shaped molecular sieve, a micropore network serving as a mechanical support is added, and the micropore proportion is improved. Meanwhile, the introduction of the microporous substrate can also adjust the distribution of the acidic sites of the molecular sieve, reduce the Al content of the outer framework and improve the catalytic efficiency. However, the presence of aluminum can hinder the growth of the nanoplatelets. At present, a double-template method can only synthesize a ZSM-5 heterozygous nanosheet molecular sieve with the silicon-aluminum ratio higher than 300, and the application of the molecular sieve in acid catalytic reaction is greatly limited.
Therefore, the development of a simple method for synthesizing the ZSM-5 hybrid nanosheet molecular sieve catalyst with the medium silica-alumina ratio is of great significance.
Disclosure of Invention
The invention aims to provide a medium silica-alumina ratio ZSM-5 heterozygous nanosheet molecular sieve and a preparation method thereof. The heterozygosis structure is formed by epitaxially growing the nanosheet structure on the surface of the blocky structure, so that the excellent diffusion performance and the open pore structure of the nanosheet molecular sieve are reserved, the microporous substrate is added, the mechanical strength of the catalyst is improved, the distribution of active sites of the catalyst is effectively adjusted, and the catalyst has good low-carbon olefin selectivity.
The purpose of the invention is realized by the following technical scheme:
1) dissolving a small molecular template agent, a silicon source and an aluminum source in water in sequence, uniformly mixing and stirring to form mixed gel;
2) stirring the mixed gel prepared in the step 1) for 3-24 hours at 40-70 ℃ to obtain aged gel;
3) cooling the aged gel obtained in the step 2) to room temperature, adding a certain amount of long carbon chain quaternary ammonium salt surfactant solution into the mixed solution, and uniformly stirring;
4) stirring the solution obtained in the step 3) at 60 ℃ for 2h to form a uniform gel solution again, and ensuring that the solution does not stratify after standing for half an hour;
5) transferring the mixed solution obtained in the step 4) into a reaction kettle, performing hydrothermal crystallization at 120-180 ℃ for 3-10d, ensuring that the reaction kettle rotates uniformly in the crystallization process, maintaining the rotating speed at 20-50rmp, obtaining a white mixed solution after crystallization, performing centrifugal separation, washing with deionized water until the centrifugal solution is neutral, drying the obtained crystallized product at 60-120 ℃ for 12-24h, and roasting the dried sample at 550 ℃ in an air atmosphere for 6h to obtain the ZSM-5 heterozygous nanosheet molecular sieve.
The small molecular template agent is one or more of tetrapropyl ammonium hydroxide (TPAOH), tetrabutyl ammonium hydroxide (TBAOH), tetrapropyl ammonium bromide (TPABr) and tetrabutyl ammonium bromide (TBABr);
the silicon source is one or more of tetraethyl orthosilicate, sodium silicate and silica sol;
the aluminum source is one or more of aluminum sulfate, aluminum nitrate, sodium metaaluminate and aluminum oxide;
the molecular formula of the long-carbon-chain quaternary ammonium salt surfactant is CnH2n+1-[N+Br-(CH3)2-C6H12]x-N+Br-(CH3)2-CmH2m+1Wherein n is 12-22, x is 1-3, and m is 6-12;
the molar ratio of each component in the mixed solution is SiO2：Al2O3: small molecule template agent: long carbon chain quaternary ammonium salt surfactant: h2O＝100：(0.17-0.5)：(20-50)：(1-10)：(800-5000)；
More preferably, SiO2：Al2O3: small molecule template agent: long carbon chain quaternary ammonium salt surfactant: h2O＝100：(0.2-0.42)：(30-40)：(1-5)：(2000-4000)；
According to the method disclosed by the invention, the medium silicon-aluminum ratio can be realized, and the molecular sieve can be always kept in a nanosheet-block heterozygous structure, so that the structural advantages of the molecular sieve are exerted; on the premise, the silicon-aluminum ratio, morphology and the like of the hybrid nano-sheet molecular sieve can be adjusted by changing the water content in the synthesized gel, the proportion and the variety of the double-template agent, the aging time, the aging temperature, the crystallization time, the crystallization temperature and the variety and the addition amount of the silicon source and the aluminum source, and the crystal form, the morphology, the microstructure and the pore canal properties of the hybrid nano-sheet molecular sieve are represented by utilizing X-ray diffraction, a scanning electron microscope, a transmission electron microscope and a nitrogen physical adsorption instrument.
Compared with the prior art, the invention has the following characteristics:
1) compared with the situation that the synthesized nano-sheet-block hybrid molecular sieve only exists in the silicon-aluminum ratio of more than or equal to 300 in the prior art, the silicon-aluminum ratio of the prepared hybrid molecular sieve is adjustable within the range of 100-300 by adjusting the proportion of the water content, the silicon source and the aluminum source;
2) the designability of the pore structure of the hybrid nanosheet molecular sieve can obtain a series of hybrid molecular sieves with different micro-mesoporous proportions by adjusting the proportion of the double templates in the synthesized gel, thereby providing possibility for the application of the hybrid nanosheet molecular sieve in catalytic reaction;
3) the thickness of the outer-layer nanosheet is adjustable, and the thickness of the outer-layer nanosheet of the hybrid nanosheet molecular sieve can be controlled to be adjustable within the range of 2-25nm by changing the molecular structure of the long carbon chain template agent.
Drawings
FIG. 1 is a TEM image of the catalyst prepared in example 1 of the present invention.
FIG. 2 is a TEM image of the catalyst prepared in example 2 of the present invention.
FIG. 3 is a TEM image of the catalyst prepared in example 3 of the present invention.
FIG. 4 is an SEM photograph of the catalyst prepared in example 4 of the present invention.
FIG. 5 is an SEM photograph of the catalyst prepared in example 6 of the present invention.
FIG. 6 is an SEM photograph of a catalyst prepared in example 9 of the present invention.
FIG. 7 is an SEM photograph of a catalyst prepared in example 12 of the present invention.
FIG. 8 is a TEM image of a catalyst prepared in example 16 of the present invention.
Detailed Description
The invention is further illustrated by the following examples.
[ examples 1-3 ] 5.105g of tetrapropylammonium hydroxide, 5.832g of tetraethyl orthosilicate, and 0.078g of aluminum sulfate octadecahydrate were weighed to prepare a mixed solution, and the mixed solution was stirred at 60 ℃ for 3 hours to obtain an aged gel. 0.610g of long carbon chain quaternary ammonium salt surfactant C22H45-N+Br-(CH3)2-C6H12-N+Br-(CH3)2-C6H13Preparing a mixed solution with 9.6g of water, adding the mixed solution into aged gel, stirring the mixed solution at 60 ℃ for 2h, transferring the mixed solution into a crystallization kettle, performing hydrothermal crystallization at 150 ℃ and a stirring speed of 30rmp for 5d, washing the synthesized sample to be neutral by using deionized water, drying the sample at 120 ℃ for 12h, and finally roasting the sample at 550 ℃ in an air atmosphere for 6h to remove a template agent to finally obtain a heterozygous nanosheet molecular sieve sample;
wherein the mass of the aluminum sulfate octadecahydrate used in example 1 is 0.078g, wherein the mass of the aluminum sulfate octadecahydrate used in example 2 is 0.063g, and wherein the mass of the aluminum sulfate octadecahydrate used in example 3 is 0.047 g.
TEM images of the catalysts prepared in examples 1-3 are shown in FIGS. 1-3. As can be seen from FIGS. 1 to 3, the morphology of the hybrid molecular sieve is determined by that the outer nanosheets grow on the surface of the bulk molecular sieve, the outer nanosheets are stacked in a cylindrical shape, the side surface of the particle has an obvious single-layer stacking morphology of the nanosheets, and the front surface is a round plane of the nanosheets, so that the morphology of the hybrid molecular sieve is not influenced by adjusting the silicon-aluminum ratio.
[ example 4-5 ] 5.105g of tetrapropylammonium hydroxide, 5.832g of tetraethyl orthosilicate, and 0.078g of aluminum sulfate octadecahydrate were weighed to prepare a mixed solution, and the mixed solution was stirred at 60 ℃ for 3 hours to obtain an aged gel. 0.610g of long carbon chain quaternary ammonium salt surfactant C22H45-N+Br-(CH3)2-C6H12-N+Br-(CH3)2-C6H13Preparing a mixed solution with 17.1g of water, adding the mixed solution into aged gel, stirring the mixed solution at 60 ℃ for 2h, transferring the mixed solution into a crystallization kettle, carrying out hydrothermal crystallization at 150 ℃ and a stirring speed of 30rmp for 5d, washing the synthesized sample to be neutral by using deionized water, drying the sample at 120 ℃ for 12h, and finally roasting the sample at 550 ℃ in an air atmosphere for 6h to remove a template agent to finally obtain a heterozygous nanosheet molecular sieve sample;
wherein the amount of water used in example 4 was 17.1g and wherein the amount of water used in example 5 was 8.8 g.
The SEM image of example 4 is shown in fig. 4. As can be seen from fig. 4, the morphology of the epitaxial growth of the nanosheet layer of the hybrid molecular sieve is still maintained, but the catalyst has a part with only an internal blocky structure and does not have particles coating the nanosheet layer, as compared with example 1, the morphology of the hybrid molecular sieve is affected by adjusting the water amount, and only by reasonably adjusting the ratio of the water amount to the silicon to aluminum to form a balance, it is ensured that the long carbon chain quaternary ammonium salt template exists in the amphiphilic equilibrium solution, that is, the formed mixed gel does not have a delamination phenomenon after standing for half an hour, and the complete hybrid molecular sieve can be synthesized.
[ example 6-8 ] 5.105g of tetrapropylammonium hydroxide, 5.832g of tetraethyl orthosilicate, and 0.078g of aluminum sulfate octadecahydrate were weighed to prepare a mixed solution, and the mixed solution was stirred at 60 ℃ for 6 hours to obtain an aged gel. Then 0.610 long carbon chain quaternary ammonium salt surfactant C is added22H45-N+Br-(CH3)2-C6H12-N+Br-(CH3)2-C6H13g and 9.6g of water are prepared into a mixed solution, the mixed solution is added into aged gel, the mixed solution is stirred for 2 hours at 60 ℃, the mixed solution is transferred to a crystallization kettle, hydrothermal crystallization is carried out for 5 days at 150 ℃ and at a stirring speed of 30rmp, the synthesized sample is washed to be neutral by deionized water, the sample is dried for 12 hours at 120 ℃, and finally the sample is roasted for 6 hours at 550 ℃ in an air atmosphere to remove a template agent, so that a heterozygous nanosheet molecular sieve sample is finally obtained;
wherein the aging time used for example 6 was 6h, wherein the aging time used for example 7 was 20h, and wherein the aging temperature used for example 8 was 70 ℃.
The SEM image of example 6 is shown in fig. 5, the morphology of the hybrid molecular sieve has no great influence, and it can be seen from comparative example 1 that the aging temperature and time during synthesis have little influence on the morphology of the hybrid nanosheet molecular sieve.
[ example 9-11 ] 5.105g of tetrapropylammonium hydroxide, 5.832g of tetraethyl orthosilicate, and 0.078g of aluminum sulfate octadecahydrate were weighed to prepare a mixed solution, and the mixed solution was stirred at 60 ℃ for 3 hours to obtain an aged gel. Then 0.610gLong carbon chain surfactant C22H45-N+Br-(CH3)2-C6H12-N+Br-(CH3)2-C6H13Preparing a mixed solution with 9.6g of water, adding the mixed solution into aged gel, stirring the mixed solution at 60 ℃ for 2h, transferring the mixed solution into a crystallization kettle, carrying out hydrothermal crystallization at 130 ℃ and a stirring speed of 30rmp for 5d, washing the synthesized sample to be neutral by using deionized water, drying the sample at 120 ℃ for 12h, and finally roasting the sample at 550 ℃ in an air atmosphere for 6h to remove a template agent to finally obtain a heterozygous nanosheet molecular sieve sample;
wherein the crystallization condition used in the example 9 is crystallization at 150 ℃ for 3d, and the stirring speed of the crystallization kettle is 30 rmp; wherein the crystallization condition used in the embodiment 10 is crystallization at 130 ℃ for 5 days, and the rotation speed of the crystallization kettle is 30 rmp; wherein the crystallization condition used in example 11 was 150 ℃ crystallization for 5 days, and the rotation speed of the crystallization vessel was 50 rmp.
The SEM image of example 9 is shown in fig. 6, compared with example 1, the crystallization time has no significant influence on the morphology of the hybrid molecular sieve, and the hybrid nanosheet molecular sieve can be synthesized under the crystallization conditions of the present invention.
[ example 12-15 ] 4.534g of tetrapropylammonium hydroxide, 5.832g of tetraethyl orthosilicate, and 0.078g of aluminum sulfate octadecahydrate were weighed to prepare a mixed solution, and the mixed solution was stirred at 60 ℃ for 3 hours to obtain an aged gel. 0.610g of long carbon chain quaternary ammonium salt surfactant C22H45-N+Br-(CH3)2-C6H12-N+Br-(CH3)2-C6H13Preparing a mixed solution with 9.6g of water, adding the mixed solution into aged gel, stirring the mixed solution at 60 ℃ for 2h, transferring the mixed solution into a crystallization kettle, carrying out hydrothermal crystallization at 150 ℃ and a stirring speed of 30rmp for 5d, washing the synthesized sample to be neutral by using deionized water, drying the sample at 120 ℃ for 12h, and finally roasting the sample at 550 ℃ in an air atmosphere for 6h to remove a template agent to finally obtain a heterozygous nanosheet molecular sieve sample;
wherein the mass of tetrapropylammonium hydroxide used in example 12 was 4.534g, wherein exampleTetrapropylammonium hydroxide used in 13 had a mass of 3.967g, whereas tetrabutylammonium hydroxide used in example 14 had a mass of 5.812g, whereas long-carbon-chain quaternary ammonium salt C used in example 1522H45-N+Br-(CH3)2-C6H12-N+Br-(CH3)2-C6H13The mass was 0.203 g.
The SEM image of example 12 is shown in fig. 7, and in contrast to example 1, the variation in the dual template ratio did not have a significant effect on the morphology of the hybrid molecular sieve. The pore characteristics of examples 1, 12, 14 and 15 are shown in table 1, and it can be seen from table 1 that the ratio and the kind of the dual template agent have great influence on the pore characteristics and the micro-mesoporous ratio of the hybrid molecule, and can be used as a means for adjusting the pore structure of the hybrid molecule.
TABLE 1 channel Properties of the catalysts obtained in examples 1, 12, 14, 15
Figure BDA0003369896620000051
[ example 16 ] 5.105g of tetrapropylammonium hydroxide, 5.832g of tetraethyl orthosilicate, and 0.078g of aluminum sulfate octadecahydrate were weighed to prepare a mixed solution, and the mixed solution was stirred at 60 ℃ for 3 hours to obtain an aged gel. 0.560g of long carbon chain quaternary ammonium salt surfactant C18H37-N+Br-(CH3)2-C6H12-N+Br-(CH3)2-C6H13Preparing a mixed solution with 9.6g of water, adding the mixed solution into aged gel, stirring the mixed solution for 2h at 60 ℃, placing the mixed solution into a crystallization kettle, carrying out hydrothermal crystallization for 5d at 150 ℃ and a stirring speed of 30rmp, washing the synthesized sample to be neutral by using deionized water, drying the sample for 12h at 120 ℃, and finally roasting the sample for 6h at 550 ℃ in an air atmosphere to remove a template agent to finally obtain a heterozygous nanosheet molecular sieve sample;
the TEM image of example 16 is shown in fig. 8, and the change of the molecular structure of the long carbon chain quaternary ammonium salt template can still ensure that the prepared molecular sieve has the appearance of a hybrid molecular sieve, but the thickness of the outer nanosheet is thicker than that in example 1, which indicates that the thickness of the outer nanosheet can be effectively adjusted by changing the structure of the long carbon chain template.
[ example 17-19 ] 5.105g of tetrapropylammonium hydroxide, 5.832g of tetraethyl orthosilicate, and 0.078g of aluminum sulfate octadecahydrate were weighed to prepare a mixed solution, and the mixed solution was stirred at 60 ℃ for 3 hours to obtain an aged gel. Then 0.610g of long carbon chain surfactant C is added22H45-N+Br-(CH3)2-C6H12-N+Br-(CH3)2-C6H13Preparing a mixed solution with 9.6g of water, adding the mixed solution into aged gel, stirring the mixed solution for 2h at 60 ℃, placing the mixed solution into a crystallization kettle, carrying out hydrothermal crystallization for 5d at 150 ℃ and a stirring speed of 30rmp, washing the synthesized sample to be neutral by using deionized water, drying the sample for 12h at 120 ℃, and finally roasting the sample for 6h at 550 ℃ in an air atmosphere to remove a template agent to finally obtain a heterozygous nanosheet molecular sieve sample;
wherein the aluminum source used in example 17 was sodium metaaluminate, wherein the silicon source used in example 18 was sodium silicate, and wherein the post-centrifugation product drying conditions used in example 19 were 60 ℃ drying for 24 hours.
The morphology of the molecular sieve synthesized in the embodiments 17 to 19 is basically the same as that of the molecular sieve synthesized in the embodiment 1, which shows that the selection of the silicon source and the aluminum source and the drying condition of the product after centrifugation have little influence on the morphology of the hybrid molecular sieve.
[ example 20 ] A single two-dimensional nanosheet molecular sieve was synthesized according to literature methods, and 1.32g of flaky sodium hydroxide was weighed into a plastic beaker and dissolved by adding a certain amount of deionized water. Then, 3.99g C was added22H45-N+Br-(CH3)2-C6H12-N+Br-(CH3)2-C6H13The templating agent was stirred at room temperature for 20 minutes to provide solution A. 0.37g of aluminum sulfate octadecahydrate was dissolved in a sulfuric acid solution to obtain a solution B. B was added dropwise to A with stirring, and the mixture was stirred at 60 ℃ for 6 h. After the solution had cooled to room temperature, 11.46g of tetra-ortho-silicic acid were addedEthyl ester and the mixture was stirred at 60 ℃ for a further 1 h. Pouring the finally obtained gel into a reaction kettle, and crystallizing for 5d at 150 ℃. Then, the molecular sieve is filtered and washed by deionized water, dried in an oven at 120 ℃ for 12h, and then roasted at 550 ℃ for 6h to obtain the single two-dimensional pure nanosheet layer molecular sieve. The catalytic performance of the catalyst was tested by using heptane cleavage as a probe reaction.
The results of the heptane cracking reaction of example 20 are listed in Table 2, and in contrast to example 1, the hybrid molecular sieve exhibited good ethylene (C) in heptane cracking2 ＝) Propylene (C)3 ＝) The selectivity and the yield of the low-carbon olefin are nearly 10% higher than that of a single two-dimensional nanosheet molecular sieve, which shows that the synergistic effect of the outer nanosheet and the internal microporous structure of the hybrid molecular sieve can realize high olefin selectivity, and the hybrid molecular sieve has a good application prospect in catalytic reaction.
TABLE 2 cracking Activity of catalysts prepared in examples 1 and 20
Figure BDA0003369896620000061

Claims (10)

1. The ZSM-5 hybrid nanosheet molecular sieve with the medium silicon-aluminum ratio is characterized in that the molecular sieve is in a particle shape, the particles are formed by combining a nanosheet structure and a blocky structure, the nanosheet structure is epitaxially grown outside the blocky structure, and the ZSM-5 hybrid nanosheet molecular sieve has the silicon-aluminum ratio of 100-300.
2. The medium silica to alumina ZSM-5 hybrid nanosheet molecular sieve of claim 1, wherein the nanosheet structure has a thickness that is tunable within a range of 2-25 nm.
3. The medium silica to alumina ratio ZSM-5 hybrid nanosheet molecular sieve of claim 1, wherein the molecular sieve particles have a particle size of 200-300 nm.
4. A process for the preparation of a meso-aluminous ZSM-5 hybrid nanosheet molecular sieve as defined in any of claims 1 to 3, comprising the steps of;
1) dissolving a small molecular template agent, a silicon source and an aluminum source in water in sequence, uniformly mixing and stirring to form mixed gel;
2) stirring the mixed gel prepared in the step 1) for 3-24 hours at 40-70 ℃ to obtain aged gel;
3) adding a long-carbon-chain quaternary ammonium salt surfactant solution into the aged gel obtained in the step 2), and uniformly stirring;
4) stirring the solution obtained in the step 3) at 60 ℃ for 2 hours to form a uniform gel solution, and ensuring that the gel solution does not generate layering phenomenon after standing for half an hour;
5) transferring the mixed solution obtained in the step 4) into a reaction kettle, carrying out hydrothermal crystallization at 120-180 ℃ for 3-10d, ensuring that the reaction kettle uniformly rotates in the crystallization process, maintaining the rotating speed at 20-50rmp, obtaining a white mixed solution after crystallization, carrying out centrifugal separation, washing by using deionized water until the centrifugal solution is neutral, drying the white solid obtained by centrifugation at 60-120 ℃ for 12-24h, and roasting the dried sample in an air atmosphere at 550 ℃ for 6h to obtain the ZSM-5 heterozygous nanosheet molecular sieve.
5. The method for preparing the medium silica to alumina ratio ZSM-5 hybrid nanosheet molecular sieve of claim 4, wherein the small molecule template is one or more of tetrapropylammonium hydroxide (TPAOH), tetrabutylammonium hydroxide (TBAOH), tetrapropylammonium bromide (TPABr), and tetrabutylammonium bromide (TBABr).
6. The method for preparing the medium silica-alumina ratio ZSM-5 hybrid nanosheet molecular sieve of claim 4, wherein the silicon source is one or more of tetraethyl orthosilicate, sodium silicate and silica sol.
7. The method for preparing the medium silica-alumina ratio ZSM-5 hybrid nanosheet molecular sieve of claim 4, wherein the source of aluminum is one or more of aluminum sulfate, aluminum nitrate, sodium metaaluminate and alumina.
8. The method for preparing the medium silica-alumina ratio ZSM-5 hybrid nanosheet molecular sieve of claim 4, wherein the long carbon chain quaternary ammonium salt surfactant has a molecular formula of CnH2n+1-[N+Br-(CH3)2-C6H12]x-N+Br-(CH3)2-CmH2m+1Wherein n is 12-22, x is 1-3, and m is 6-12.
9. The method for preparing the medium silica-alumina ratio ZSM-5 hybrid nanosheet molecular sieve of claim 4, wherein the components of the mixed solution are in a molar ratio of SiO2：Al2O3: small molecule template agent: long carbon chain quaternary ammonium salt surfactant: h2O＝100：(0.17-0.5)：(20-50)：(1-10)：(800-5000)。
10. The method for preparing a medium silica to alumina ZSM-5 hybrid nanosheet molecular sieve of claim 4, wherein the mixed solution comprises silica and water in a molar ratio of SiO2：H2O＝100：(2000-4000)。
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CN115845906A (en) * 2022-12-01 2023-03-28 黄河三角洲京博化工研究院有限公司 Preparation method of catalyst for heavy oil to produce more light olefins and aromatic hydrocarbons
CN117466710A (en) * 2023-12-27 2024-01-30 内蒙古工业大学 Method for catalytic oxidation of cyclohexane by magnetic cobalt phosphate molecular sieve
CN117466710B (en) * 2023-12-27 2024-05-10 内蒙古工业大学 Method for catalytic oxidation of cyclohexane by magnetic cobalt phosphate molecular sieve

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CN114804143A (en) * 2022-05-17 2022-07-29 宁夏大学 Nano-lamella ZSM-5 molecular sieve and preparation method thereof
CN115124049A (en) * 2022-07-16 2022-09-30 浙江大学 Method for synthesizing FER zeolite nanosheet with controllable thickness by using small-molecule template agent
CN115124049B (en) * 2022-07-16 2023-07-21 浙江大学 Method for synthesizing FER zeolite nano-sheet with controllable thickness by using small molecular template agent
CN115845906A (en) * 2022-12-01 2023-03-28 黄河三角洲京博化工研究院有限公司 Preparation method of catalyst for heavy oil to produce more light olefins and aromatic hydrocarbons
CN117466710A (en) * 2023-12-27 2024-01-30 内蒙古工业大学 Method for catalytic oxidation of cyclohexane by magnetic cobalt phosphate molecular sieve
CN117466710B (en) * 2023-12-27 2024-05-10 内蒙古工业大学 Method for catalytic oxidation of cyclohexane by magnetic cobalt phosphate molecular sieve

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