阅读说明：本技术 纳米y沸石的合成方法、合成的纳米y沸石及用途 (Synthesis method of nano Y zeolite, synthesized nano Y zeolite and application ) 是由 胥明 高焕新 于 2018-06-06 设计创作，主要内容包括：本发明涉及一种纳米Y沸石的合成方法、合成的纳米Y沸石及用途。所述方法包括步骤：a)使铝源与氢氧化钠溶液接触,得到铝源溶液；所述接触温度为50～95℃；b)使硅源与氢氧化钠溶液接触,得到硅源溶液；所述接触温度为70～100℃；c)使所述铝源溶液与所述硅源溶液在冰水混合浴的条件接触,得到混合物；d)使所述混合物晶化,得到所述纳米Y分子筛。所述方法可用于纳米Y沸石的工业生产中。(the invention relates to a method for synthesizing nano Y zeolite, the synthesized nano Y zeolite and application. The method comprises the following steps: a) contacting an aluminum source with a sodium hydroxide solution to obtain an aluminum source solution; the contact temperature is 50-95 ℃; b) contacting a silicon source with a sodium hydroxide solution to obtain a silicon source solution; the contact temperature is 70-100 ℃; c) contacting the aluminum source solution with the silicon source solution under the condition of an ice-water mixed bath to obtain a mixture; d) crystallizing the mixture to obtain the nano Y molecular sieve. The method can be used for industrial production of the nano Y zeolite.)

1. A method for synthesizing nano Y zeolite comprises the following steps:

a) contacting an aluminum source with a sodium hydroxide solution to obtain an aluminum source solution; the contact temperature is 50-95 ℃;

b) Contacting a silicon source with a sodium hydroxide solution to obtain a silicon source solution; the contact temperature is 70-100 ℃;

c) Contacting the aluminum source solution with the silicon source solution under the condition of an ice-water mixed bath to obtain a mixture;

d) Crystallizing the mixture to obtain the nano Y molecular sieve.

2. The method for synthesizing nano Y zeolite of claim 1, wherein Na is used₂O、Al₂O₃And H₂Calculated by O, in the aluminum source solution, Na₂O:Al₂O₃:H₂The molar ratio of O is 2-18:1: 10-50.

3. The method for synthesizing nano Y zeolite of claim 1, wherein Na is used₂O、SiO₂And H₂In the silicon source solution, the content of Na is measured by O₂O:SiO₂:H₂The molar ratio of O is 0.5-2:1: 30-150.

4. The method for synthesizing nano Y zeolite of claim 1, wherein Na is used₂O、Al₂O₃、SiO₂And H₂Calculated as O, in said mixture, Na₂O:Al₂O₃:SiO₂:H₂the molar ratio of O is 7-9:0.6-0.9:10:40-200, preferably 7-9:0.7-0.9:10: 60-160.

5. The method for synthesizing nano Y zeolite of claim 1, wherein the crystallization conditions of the mixture comprise: the crystallization temperature is 50-80 ℃, and preferably 50-70 ℃; the crystallization time is 24 to 72 hours, preferably 24 to 48 hours.

6. The method for synthesizing nano Y zeolite of claim 1, wherein the aluminum source is at least one selected from the group consisting of sodium aluminate, sodium metaaluminate, aluminum powder and alumina; the silicon source is at least one selected from the group consisting of silica sol and water glass.

7. A nano Y zeolite synthesized by the method of any one of claims 1 to 6.

8. The nano Y zeolite of claim 7, wherein the nano Y zeolite has an average grain diameter of less than 50 nm.

9. The nano Y zeolite of claim 7, wherein the nano Y zeolite has a silica to alumina molar ratio of 1.6 to 2.5.

10. A nano Y zeolite composition comprising the nano Y zeolite synthesized by the method for synthesizing nano Y zeolite according to any one of claims 1 to 6 or the nano Y zeolite according to any one of claims 7 to 9, and a binder.

11. Use of a nano Y zeolite synthesized according to the method for synthesizing nano Y zeolite of any one of claims 1 to 6, a nano Y zeolite of any one of claims 7 to 9, or a nano Y zeolite composition of claim 9 as a catalyst for the reaction of benzene and long-chain olefins to produce long-chain alkylbenzenes.

12. Use according to claim 11, wherein the conditions of the reaction of benzene and long chain olefins to produce long chain alkyl benzene comprise: the reaction temperature is 100-250 ℃, and preferably 120-200 ℃; the reaction pressure is 0.1-3.0 MPa, preferably 1.5-2.5 MPa; the weight space velocity of the long-chain olefin is 0.1-2 hours^-1(ii) a The molar ratio of benzene to long-chain olefin is not less than 8:1, preferably 8:1 to 30: 1.

Technical Field

The invention relates to a method for synthesizing nano Y zeolite, the synthesized nano Y zeolite and application.

Background

The long-chain alkylbenzene is the main raw material for preparing sodium alkyl benzene sulfonate used as synthetic detergent. In the current industrial production, hydrofluoric acid is generally adopted as a catalyst for production. Although the hydrofluoric acid method has the advantages of mild reaction conditions, simple reactor and low benzene-olefin ratio, the hydrofluoric acid method is difficult to adapt to increasingly higher environmental requirements due to the strong corrosivity and toxicity of hydrofluoric acid, and has a series of problems of easy corrosion of equipment, poor working conditions and the like. The development of a novel solid acid alkylation process without corrosion and pollution instead of a hydrofluoric acid process becomes an inevitable development trend of a long-chain alkylbenzene production technology.

Currently, the solid acid process that has been commercialized is a fluorine-containing SiO process developed by cooperation of UOP and Petresa, Spanish₂-Al₂O₃A solid acid catalyst.

The most studied solid acid catalysts in China are zeolite molecular sieves and some metal oxides. As long-chain alkylbenzene molecules are relatively large, ten-membered rings and channels below the ten-membered rings cannot enter, and only mordenite, Y zeolite, Beta zeolite, MCM-22 and other molecular sieves with twelve-membered rings hopefully have good catalytic performance on alkylation reaction of benzene and long-chain olefin. The research reports about the long-chain olefin alkylation reaction catalyst are less, the biggest problems when the catalyst is applied to the synthesis of long-chain alkylbenzene are that the catalyst is easy to deactivate and has short service life cycle, and coke or polyalkylbenzene generated in the reaction is easy to block the pore channels of the carrier. The Y zeolite as catalyst and zeolite-base catalyst may be used in catalytic cracking, catalytic hydrocracking and catalytic hydrotreating process, and is also the molecular sieve with the largest petrochemical application amount, and the annual production capacity of Chinese Y-type zeolite is over 5 ten thousand tons and is increasing. With the development of nanotechnology, ultrafine zeolite has large external specific surface area, short diffusion distance and more exposed active centers, so that catalytic activity and stability can be improved, the deactivation rate of the catalyst is slowed down, and the formation of carbon deposition is reduced, thereby bringing about extensive attention and research of people. Therefore, the preparation of ultra-fine Y zeolite has become a trend.

Traditional ultrafine Y zeolite synthesis requires the addition of an organic templating agent to the synthesis solution, with tetramethylammonium hydroxide being the most common. However, the synthesis of the nano zeolite by using the organic template has many disadvantages, such as that the removal of the template generally adopts a roasting method, which easily causes irreversible agglomeration of the nano zeolite; the use of the template can cause the silicon-aluminum ratio and the pore diameter of the finally obtained zeolite to be slightly changed, thereby seriously limiting the industrial application of the nano zeolite; organic templating agents are expensive and the use of organic templating agents can pollute the environment. The template-free synthesis method is generally completed by firstly preparing a directing agent, then adding a silicon source and an aluminum source into the directing agent to prepare a synthetic solution, and finally performing hydrothermal crystallization. The preparation of the synthetic liquid does not need to add other substances (such as a template) besides a silicon source and an aluminum source. Currently, the industrial production methods of Y-type zeolite include kaolin in-situ crystallization method (BASF, USP494902), gel guiding agent method (Grace, USP3639099), and kaolin raw powder in-situ crystallization method (China petrochemical, CN 15333982A). However, the particle size of the Y zeolite directly prepared by the existing synthesis method is large, generally from several micrometers to tens of micrometers, and it is difficult to obtain nano zeolite, especially ultra-fine Y zeolite with the particle size less than 50 nanometers. CN1046488C et al reported that zeolite Y having a particle size of about 100-500nm was prepared by a method of synthesizing a directing agent and then synthesizing a gel. In addition, there are some methods (USP3516786, EP0041338A) in which the preparation of nano zeolite is carried out by adding a dispersion medium and an organic substance to the system, and there are disadvantages in that the cost is high and the environmental pollution is serious.

Disclosure of Invention

The inventor of the invention assiduously researches on the basis of the prior art and discovers a novel synthesis method of nano Y zeolite. The method comprises the following steps: heating to dissolve silicon source and aluminum source to prepare silicon source solution and aluminum source solution, forming colloid at low temperature, and heating for crystallization. It has at least an advantage of low synthesis cost as compared with the prior art, and the present invention has been completed based on this finding.

In particular, the invention relates to a synthesis method of nano Y zeolite. The method comprises the following steps:

a) contacting an aluminum source with a sodium hydroxide solution to obtain an aluminum source solution; the contact temperature is 50-95 ℃;

b) Contacting a silicon source with a sodium hydroxide solution to obtain a silicon source solution; the contact temperature is 70-100 ℃;

c) Contacting the aluminum source solution with the silicon source solution under the condition of an ice-water mixed bath to obtain a mixture;

d) Crystallizing the mixture to obtain the nano Y molecular sieve.

The invention also provides a nano Y zeolite prepared by the method.

The invention also provides a nano Y zeolite composition, which comprises the nano Y zeolite prepared by the method or the nano Y zeolite and a binder.

The invention also provides the application of the nano Y zeolite prepared by the method.

the invention has the technical effects that:

According to the synthesis method of the nano Y zeolite, the conventional guiding agent in the prior art is not needed, and the Y zeolite which is prepared by the guiding agent method and has a typical Y zeolite XRD diffraction peak can be finally obtained. Particularly, the traditional nano Y zeolite has poor thermal stability, the structure is easy to collapse after high-temperature roasting, the nano Y zeolite synthesized by the invention has good thermal stability, and the nano structure of a roasted sample still keeps good.

according to the synthesis method of the nanometer Y zeolite, a guide agent method commonly adopted in the prior art is omitted, the silicon source solution and the aluminum source solution are prepared by heating and dissolving the silicon source and the aluminum source, low-temperature colloid forming and high-temperature crystallization are adopted to prepare the Y zeolite, the manufacturing process of the Y zeolite is greatly simplified, the manufacturing of the Y zeolite is easier, the repeatability is good, and the industrialization prospect is wide.

According to the synthesis method of the nano Y zeolite, an organic template is not used. The addition of the template agent not only increases the crystallization time, but also has high price and complex structure. Furthermore, the templating agent present in the zeolite needs to be removed in a subsequent process without affecting the use of the zeolite, which tends to cause environmental pollution. Therefore, an organic template agent is not used, the production cost is reduced, meanwhile, the nitrogen-containing wastewater is greatly reduced, the post-treatment is easy, and the environment is green and friendly.

According to the synthesis method of the nano Y zeolite, the Y zeolite with small grains less than 50 nanometers can be prepared by the methods of low-temperature colloid formation and temperature rise crystallization. The zeolite with small crystal grains has large external specific surface area, short diffusion distance and more exposed active centers, and effectively inhibits strong acid active centers on the surface of the zeolite, thereby improving the catalytic activity and stability, slowing down the deactivation rate of the catalyst and reducing the formation of carbon deposit. The nanometer Y zeolite is applied to the alkylation process of benzene and long-chain olefin, reduces oligomerization reaction of the long-chain olefin on the surface of the catalyst, enables reaction products to be rapidly diffused out of catalyst pore channels, effectively inhibits reaction materials from dehydrocyclization on the surface of the catalyst to generate carbon deposition, and improves the activity and stability of the catalyst in the reaction of the long-chain alkylbenzene. In addition, the particle size of the catalyst has correlation with the reaction performance, and the smaller the particle size is in the reaction of preparing long-chain alkylbenzene, the higher the catalytic activity and stability are reflected.

drawings

Fig. 1 is a Scanning Electron Microscope (SEM) photograph of Cat-1, a product prepared according to the present invention [ example 1 ].

Fig. 2 is a Scanning Electron Microscope (SEM) photograph of Cat-2, a product prepared according to the present invention [ example 2 ].

fig. 3 is an XRD spectrum of the product Cat-1 prepared in the present invention [ example 1 ] after calcination.

FIG. 4 is a Scanning Electron Microscope (SEM) photograph of the prepared product Cat-1 [ comparative example 1 ].

Detailed Description

The following detailed description of the embodiments of the present invention is provided, but it should be noted that the scope of the present invention is not limited by the embodiments, but is defined by the appended claims.

All publications, patent applications, patents, and other references mentioned in this specification are herein incorporated by reference in their entirety. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present specification, including definitions, will control.

When the specification concludes with claims with the heading "known to those skilled in the art", "prior art", or the like, to derive materials, substances, methods, procedures, devices, or components, etc., it is intended that the subject matter derived from the heading encompass those conventionally used in the art at the time of filing this application, but also include those that are not currently in use, but would become known in the art to be suitable for a similar purpose.

In the context of the present specification, the structure of nano-Y zeolites is determined by X-ray diffraction pattern (XRD) determined by X-ray powder diffractometry using a Cu-ka radiation source, K α 1 wavelength λ 1.5405980 angstromsA nickel filter.

In the context of the present specification, the average grain diameter of the nano Y zeolite is determined by Scanning Electron Microscopy (SEM), using a Nova NanoSEM450 SEM from FEI, a sufficiently dried sample is fixed on a sample tray with conductive glue, and after evacuation to 10-4Pa, scanning tests are performed.

In the context of the present specification, the term "relative crystallinity" refers to the relative crystallinity of a zeolite before and after calcination as measured by X-ray diffraction. And taking eight main peaks on the X-ray diffraction spectrum of the sample as representatives, adding the intensities of the peaks, and taking the sample before roasting as a standard to calculate the relative crystallinity of the sample after roasting.

It should be expressly understood that two or more of the aspects (or embodiments) disclosed in the context of this specification can be combined with each other as desired, and that such combined aspects (e.g., methods or systems) are incorporated in and constitute a part of this original disclosure, while remaining within the scope of the present invention.

Unless otherwise expressly indicated, all percentages, parts, ratios, etc. mentioned in this specification are by weight unless otherwise not in accordance with the conventional knowledge of those skilled in the art.

According to one aspect of the invention, a method for synthesizing nano Y zeolite is provided. The method comprises the following steps:

a) contacting an aluminum source with a sodium hydroxide solution to obtain an aluminum source solution; the contact temperature is 50-95 ℃;

b) Contacting a silicon source with a sodium hydroxide solution to obtain a silicon source solution; the contact temperature is 70-100 ℃;

c) Contacting the aluminum source solution with the silicon source solution under the condition of an ice-water mixed bath to obtain a mixture;

d) Crystallizing the mixture to obtain the nano Y molecular sieve.

According to one aspect of the invention, step a) is carried out with Na₂O、Al₂O₃And H₂Calculated by O, in the aluminum source solution, Na₂O:Al₂O₃:H₂The molar ratio of O is 2-18:1: 10-50.

According to one aspect of the invention, step b) is carried out with Na₂O、SiO₂And H₂In the silicon source solution, the content of Na is measured by O₂O:SiO₂:H₂The molar ratio of O is 0.5-2:1: 30-150.

According to one aspect of the invention, step c) is carried out with Na₂O、Al₂O₃、SiO₂And H₂Calculated as O, in said mixture, Na₂O:Al₂O₃:SiO₂:H₂the molar ratio of O is 7-9:0.6-0.9:10:40-200, preferably 7-9:0.7-0.9:10: 60-160.

According to one aspect of the invention, the crystallization conditions of the mixture in step d) include: the crystallization temperature is 50-80 ℃, and preferably 50-70 ℃; the crystallization time is 24 to 72 hours, preferably 24 to 48 hours.

According to one aspect of the invention, the aluminum source is at least one selected from the group consisting of sodium aluminate, sodium metaaluminate, aluminum powder, and alumina; the silicon source is at least one selected from the group consisting of silica sol and water glass.

According to an aspect of the present invention, in the synthesis method of nano Y zeolite, after the crystallization is completed, nano Y zeolite may be separated from the obtained reaction mixture as a product by any separation means conventionally known. The separation method includes, for example, a method of filtering, washing and drying the obtained reaction mixture.

According to an aspect of the present invention, in the method for synthesizing nano Y zeolite, the filtering, washing and drying may be performed in any manner conventionally known in the art. Specifically, for example, the reaction mixture obtained may be simply filtered by suction. Examples of the washing include washing with deionized water. The drying temperature is, for example, 40 to 250 ℃, preferably 60 to 150 ℃, and the drying time is, for example, 8 to 30 hours, preferably 10 to 20 hours. The drying may be carried out under normal pressure or under reduced pressure.

According to one aspect of the present invention, the obtained nano Y zeolite is synthesized according to the method for synthesizing nano Y zeolite.

According to one aspect of the invention, the nano Y zeolite has an average grain diameter of less than 50 nanometers, such as 5, 10, 15, 20, 25, 30, 35, 40, 45 nanometers.

According to one aspect of the invention, the molar ratio of silica to alumina of the nano Y zeolite is 1.6-2.5.

According to one aspect of the invention, the nano Y zeolite may be in any physical form, such as a powder, granules, or molded article (e.g., a bar, clover, etc.). These physical forms can be obtained in any manner conventionally known in the art and are not particularly limited.

According to an aspect of the present invention, the nano Y zeolite may be used in combination with other materials, thereby obtaining a nano Y zeolite composition. Examples of the other materials include active materials and inactive materials. Examples of the active material include synthetic zeolite and natural zeolite, and examples of the inactive material (generally referred to as a binder) include clay, silica gel, and alumina. These other materials may be used singly or in combination in any ratio. As the amount of the other materials, those conventionally used in the art can be directly referred to, and there is no particular limitation.

According to one aspect of the invention, the nano Y zeolite synthesized by the synthesis method of the nano Y zeolite, the nano Y zeolite or the nano Y zeolite composition can be used as a catalyst for a reaction for preparing long-chain alkylbenzene from benzene and long-chain olefin.

According to one aspect of the present invention, the conditions for the reaction of benzene and long chain olefins to produce long chain alkylbenzene comprise: the reaction temperature is 100-250 ℃, and preferably 120-200 ℃; the reaction pressure is 0.1-3.0 MPa, preferably 1.5-2.5 MPa; the weight space velocity of the long-chain olefin is 0.1-2 hours^-1(ii) a The molar ratio of benzene to long-chain olefin is not less than 8:1, preferably 8:1 to 30: 1.

According to one aspect of the invention, the source of the long-chain olefin can be an alkane olefin mixture containing 10-80% of olefin obtained from Fischer-Tropsch synthesis reaction, and the linearity of the olefin is more than 90%; may be an alkene obtained by dehydrogenation of a linear alkane; or mono-olefins obtained by deoxygenation, hydrocracking, and dehydrogenation of natural oils. The long-chain olefin preferably has 8 to 16 carbon atoms, and more preferably has 9 to 14 carbon atoms. The olefin is an acyclic mono-olefinic compound. The location of the olefinic bond in the molecule is not critical, as most alkylation catalysts have been found to promote migration of the olefinic bond.

The invention is further illustrated by the following specific examples.

[ example 1 ]

Firstly, preparing an aluminum source solution, weighing 20g of NaOH, dissolving in 40g of water, adding 1.9g of aluminum powder, stirring in a water bath at 60 ℃ for 10min, and then placing in an ice-water mixed bath. Then, preparing a silicon source solution, weighing 16g of NaOH, dissolving in 59g of water, adding 75g of silica sol, heating at 100 ℃ for 10min to fully dissolve the silica sol, and placing the solution in an ice-water mixed bath environment after the solution is transparent. And slowly dropwise adding the aluminum source solution into the silicon source solution, and stirring for 24 hours to obtain a mixture. Then the mixture is heated to 50 ℃ and is kept still for crystallization for 50 hours. Washing the product with water until the pH value of the washing liquid is less than 10, filtering, and drying at 80 ℃ for 12 hours to obtain the nano Y zeolite, wherein the morphology is illustrated by figure 1, and the average grain diameter is 10 nanometers. The catalyst was named Cat-1 with a silica to alumina molar ratio of 13.3.

Wherein in the mixture, Na is added₂O、Al₂O₃、SiO₂And H₂Calculated as O, Na₂O:Al₂O₃:SiO₂:H₂The molar ratio of O is 9:0.75:10: 118.

[ example 2 ]

First, an aluminum source solution was prepared, 18g of NaOH was weighed and dissolved in 38g of water, 3.6g of alumina powder was added, and the mixture was stirred in a water bath at 80 ℃ for half an hour and then placed in a mixed bath of ice and water. Then, preparing a silicon source solution, weighing 16g of NaOH, dissolving in 59g of water, adding 75g of silica sol, heating at 100 ℃ for 10min to fully dissolve the silica sol, and placing the solution in an ice-water mixed bath environment after the solution is transparent. And slowly dropwise adding the aluminum source solution into the silicon source solution, and stirring for 24 hours to obtain a mixture. Then the mixture is heated to 60 ℃ and is kept still for crystallization for 45 hours. Washing the product with water until the pH value of the washing liquid is less than 10, filtering, and drying at 80 ℃ for 12 hours to obtain the nano Y zeolite, wherein the morphology is illustrated by figure 2, and the average grain diameter is 30 nanometers. The catalyst was named Cat-2, and the molar ratio of silica to alumina was 13.3.

Wherein in the mixture, Na is added₂O、Al₂O₃、SiO₂And H₂Calculated as O, Na₂O:Al₂O₃:SiO₂:H₂The molar ratio of O is 8.5:0.75:10: 118.

[ example 3 ]

Cat-1 prepared in [ example 1 ] was calcined at 550 ℃ for 4 hours, and XRD results are shown in FIG. 3. The relative crystallinity of the zeolite after calcination was measured by X-ray diffraction and found to be 93%. Therefore, the Y zeolite prepared by the method has small crystal grains, still has higher relative crystallinity after being calcined at 550 ℃, and has good structural stability.

[ example 4 ]

5g of the catalyst [ example 1-2 ] was loaded in a fixed bed reactor and then a mixture of benzene and long chain olefins (long chain olefins are commercial mixed olefins with an average carbon number of 11-13, 10% olefin content from Nanjing alkylbenzene works) was passed in a 10:1 benzene to olefin ratio. The reaction conditions are as follows: the weight space velocity of olefin is 0.5h^-1The reaction temperature is 160 ℃, and the reaction pressure is 2.0 MPa. The reaction results are shown in Table 1.

Comparative example 1

at room temperature, mixing water glass, sodium metaaluminate, sodium hydroxide and deionized water according to the formula of n (Al)₂O₃):n(SiO₂):n(Na₂O):n(H₂Mixing O) ═ 1:9.2:8.15:180 in a beaker, standing and aging for 10h, placing in a polytetrafluoroethylene lined reaction kettle, crystallizing at 90 ℃ for 48h, washing the product with water until the pH value of the washing liquid is less than 10, filtering, and drying at 80 ℃ for 12 h to obtain Y zeolite, wherein the morphology is illustrated by figure 4, and the average grain diameter is 1000 nm. The catalyst was named Con-1, and the molar ratio of silica to alumina was 9.2.

Comparative example 2

First, an aluminum source solution was prepared, 20g of NaOH was weighed and dissolved in 38g of water, 3.6g of alumina powder was added, and the mixture was stirred at 25 ℃ for half an hour and then placed in an ice-water mixed bath. Then, preparing a silicon source solution, weighing 16g of NaOH, dissolving in 59g of water, adding 75g of silica sol, dissolving at 25 ℃, and placing in an ice-water mixed bath environment after the solution is transparent. And slowly dropwise adding the aluminum source solution into the silicon source solution, and stirring for 24 hours to obtain a mixture. Then the mixture is heated to 60 ℃ and is kept still for crystallization for 45 hours. Washing the product with water until the pH value of the washing liquid is less than 10, filtering, and drying at 80 ℃ for 12 hours to obtain the nano Y zeolite, wherein the morphology is illustrated by figure 2, and the average grain diameter is 30 nanometers. The catalyst was named Cat-2, and the molar ratio of silica to alumina was 13.3.

Wherein in the mixture, Na is added₂O、Al₂O₃、SiO₂And H₂Calculated by O, the molar ratio of Na2O to Al2O3 to SiO2 to H2O is 9:0.75:10: 118.

Comparative example 3

Firstly, preparing an aluminum source solution, weighing 20g of NaOH, dissolving in 40g of water, adding 1.9g of aluminum powder, stirring in a water bath at 60 ℃ for 10min, and then placing in an ice-water mixed bath. Then, preparing a silicon source solution, weighing 16g of NaOH, dissolving in 59g of water, adding 75g of silica sol, heating at 100 ℃ for 10min to fully dissolve the silica sol, and placing the solution in an environment at 25 ℃ after the solution is transparent. And slowly dropwise adding the aluminum source solution into the silicon source solution, and stirring for 24 hours to obtain a mixture. Then the mixture is heated to 50 ℃ and is kept still for crystallization for 50 hours. Washing the product with water until the pH value of the washing liquid is less than 10, filtering, and drying at 80 ℃ for 12 hours to obtain the nano Y zeolite, wherein the morphology is illustrated by figure 1, and the average grain diameter is 10 nanometers. The catalyst was named Cat-1 with a silica to alumina molar ratio of 13.3.

Wherein in the mixture, Na is added₂O、Al₂O₃、SiO₂And H₂Calculated as O, Na₂O:Al₂O₃:SiO₂:H₂The molar ratio of O is 9:0.75:10: 118.

Comparative example 4

Similarly [ example 4 ], catalysts synthesized [ comparative examples 1 to 3 ] were evaluated. The results are shown in Table 1.

TABLE 1

As can be seen from the results in the tables, the catalysts Cat-01, Cat-02 of the examples of the present invention have higher reactivity and stability than the comparative examples Con-01, Con-02, Con-03. From the reaction results, the smaller the particle size of the catalyst, the higher the catalytic activity and the better the stability. The method of the invention effectively improves the catalytic activity and stability of the Y zeolite in the alkylation reaction of benzene and long-chain olefin.