High-silicon Y molecular sieve as well as synthesis method and application thereof

Abstract

The invention provides a high-silicon Y molecular sieve as well as a synthesis method and application thereof. The high-silicon Y molecular sieve is characterized in that the high-silicon Y molecular sieve is obtained by a direct hydrothermal synthesis method, the silicon-aluminum molecular ratio of the high-silicon Y molecular sieve is greater than 10, the specific surface area is greater than 900 m < 2 > / g, the total acid content is greater than 0.8 mmol / g, and the strong acid proportion is greater than 45%. The synthesis process of the molecular sieve is simple, the synthesized molecular sieve is high in crystallinity and purity, high in acid strength and low in acid density, and when the molecular sieve is used as a catalytic cracking catalyst, the reaction activity and the service life of the catalyst can be improved.

Description

Technical Field

[0001] The invention relates to a high-silicon Y molecular sieve and a synthesis method and application thereof. Background Art

[0002] Y molecular sieve with FAU topology is widely used as the main active component of catalyst in petroleum refining and processing due to its strong acidity and large pore structure, and its industrial consumption is huge. However, the low silicon skeleton characteristics of conventional Y molecular sieve (SiO2 / Al2O3 molar ratio: 3-6) lead to its structural instability, which becomes the main bottleneck for direct application. In order to overcome this problem, both research and industrial practice have shown that increasing the silicon-aluminum ratio of the Y molecular sieve framework is an effective method. As the silicon-aluminum ratio increases, the acid strength of the Y molecular sieve increases, while the acid amount decreases accordingly. This change not only helps to inhibit the carbon deposition behavior during the cracking reaction, but also significantly improves the reaction activity of the catalyst. In addition, the thermal stability and hydrothermal stability of the high silicon-aluminum ratio Y molecular sieve will also increase accordingly, which is conducive to the catalyst to maintain stable performance during long-term use.

[0003] High-silicon Y molecular sieve, whose silicon-aluminum oxide ratio is usually greater than 6, is an important catalyst component in petroleum refining and processing. Its preparation methods are mainly divided into direct synthesis method and post-treatment preparation method. The post-treatment preparation method aims to remove part of the skeleton aluminum to increase the silicon-aluminum ratio through chemical or physical means such as high-temperature steam dealumination, solution dealumination, etc. However, this process will introduce mesopores and may cause the amorphous phase to block the micropores and mesopore channels, reducing the crystallinity and the number of active sites. At the same time, the energy consumption is high, and the pore size and pore volume of the mesopores are difficult to control. In addition, the surface of the molecular sieve will preferentially dealuminate, resulting in a gradient of dealuminate inside and outside the crystal. Excess silicate will be enriched on the surface of the crystal to form a silicon-rich surface, affecting the accessibility of the surface active center, resulting in poor catalytic activity, complex process and high energy consumption, and inevitably introducing a large number of defects, resulting in problems such as reduced crystallinity and uneven distribution of aluminum atoms.

[0004] Compared with the post-treatment method, the high-silicon Y zeolite obtained by the direct synthesis method has attracted much attention from the industry and researchers due to its advantages such as simple preparation process, high crystallinity, relatively uniform aluminum distribution and good framework stability. Depending on whether an organic template is introduced, it can be divided into inorganic system synthesis and organic template system synthesis.

[0005] The Chinese patent with publication number CN116730356A, titled "A high silicon-aluminum ratio nanocluster Y-type molecular sieve and its preparation method and application", uses fatty alcohol polyoxyethylene ether sulfate (AES) as a template to prepare Y molecular sieve crystals with a silicon-aluminum ratio of 6-7 and a grain size of about 100nm. The medium pores are short, which can shorten the diffusion path of reactants in the zeolite pores, reduce the diffusion time, and accelerate the diffusion rate.

[0006] The Chinese patent with publication number CN107777698A, named B-NaY molecular sieve and its preparation method and use, increases the activity of the directing agent by adding a certain amount of boron source to the directing agent, and at the same time increases the silicon-aluminum ratio of the Y molecular sieve by about 0.3, thereby obtaining a Y molecular sieve with a silicon-aluminum ratio of more than 6 and a grain size of 50-150nm.

[0007] In summary, most of the research on the direct synthesis of Y molecular sieves has a silicon-aluminum ratio between 6 and 10. For processes such as hydrocracking, the thermal stability and hydrothermal stability of molecular sieves with a silicon-aluminum ratio below 10 cannot meet industrial requirements.

[0008] In summary, the current research on direct synthesis of Y molecular sieves is mainly focused on the range of Si / Al ratio of 6-10. However, for specific processes such as hydrocracking, the performance of these molecular sieves with Si / Al ratio below 10 in terms of thermal stability and hydrothermal stability still cannot meet the standard requirements for industrial applications. Therefore, in order to meet industrial needs, it is necessary to study the synthesis method of Y molecular sieves with Si / Al ratio exceeding 10. Summary of the invention

[0009] The invention aims to solve the problem of preparing a Y molecular sieve with a silicon-aluminum ratio of more than 10, and proposes a high-silicon Y molecular sieve and a synthesis method and application thereof.

[0010] The technical method of the present invention is as follows:

[0011] The present invention provides a high-silicon Y molecular sieve, which is obtained by a direct hydrothermal synthesis method, and the high-silicon Y molecular sieve has a silicon-aluminum molecular ratio greater than 10 and a specific surface area greater than 900m 2 / g, the total acid content is greater than 0.8mmol / g, and the proportion of strong acid is greater than 45%.

[0012] The present invention also provides a method for synthesizing a high-silicon Y molecular sieve, the method comprising:

[0013] 1) mixing aluminum source Al1, sodium source Na1, template agent R1 and deionized water, adding mixed organic silicon source Si1, mixing and crystallizing to obtain a directing agent;

[0014] 2) mixing aluminum source Al2, sodium source Na2, template agent R2 and deionized water, adding silicon source Si2 to obtain an initial gel, and adding a directing agent to the initial gel to obtain a synthetic gel;

[0015] 3) Crystallizing, washing, drying and calcining the synthesized gel to obtain a high-silicon Y molecular sieve.

[0016] Specifically, the molar numbers of the aluminum sources Al1 and Al2 in step 1) and step 2) are calculated as Al2O3; the molar numbers of the sodium sources Na1 and Na2 are calculated as Na2O; the molar numbers of the templates R1 and R2 are calculated as the molar numbers of R1 and R2 themselves, respectively; the molar numbers of the silicon sources Si1 and Si2 are calculated as SiO2;

[0017] In step 1), the aluminum source Al1, the sodium source Na1, the template R1, the deionized water, and the mixed organic silicon source Si1 have the following molar ratio:

[0018] Na2O / SiO2=0.001-0.015;

[0019] Na2O / Al2O3=0.05-0.15;

[0020] H2O / Na2O=1500-3000;

[0021] R1 / Al2O3=5-7;

[0022] In step 2), the aluminum source Al2, the sodium source Na2, the template R2, the deionized water, the silicon source Si2, and the directing agent have the following molar ratio:

[0023] Na2O / SiO2=0.01-0.2;

[0024] Na2O / Al2O3=0.1-3;

[0025] H2O / Na2O=100-180;

[0026] R2 / Al2O3=3-5;

[0027] The mass ratio of the amount of the directing agent added in step 1) to the SiO2 in the initial gel is 0.05-0.15;

[0028] The silicon source Si1 in step 1) includes silane and silicate, and the mass ratio of silane and silicate is 0.01-0.2 based on SiO2.

[0029] Specifically, in step 1), the crystallization step includes: crystallization at 20-30°C for 1-5h under vigorous stirring, crystallization at 40-60°C for 10-20h under static conditions, and crystallization at 80-120°C for 30-80h under static conditions; preferably, in step 1), crystallization at 25°C for 2h under vigorous stirring, crystallization at 50°C for 15h under static conditions, and crystallization at 100°C for 50h under static conditions.

[0030] Specifically, in step 3), the crystallization step comprises: crystallization at 100-130° C. for 8-12 days under static conditions; preferably, in step 3), crystallization at 120° C. for 10 days under static conditions.

[0031] Specifically, the aluminum sources Al1 and Al2 in step 1) and step 2) are independently selected from at least one of aluminum isopropoxide, aluminum sec-butoxide, and sodium metaaluminate.

[0032] Specifically, Na1 and Na2 in step 1) and step 2) are independently selected from sodium hydroxide.

[0033] Specifically, the templates R1 and R2 in step 1) and step 2) are independently selected from quaternary ammonium salts, and the quaternary ammonium salts include tetraalkylammonium hydroxide and / or tetrabutylammonium hydroxide.

[0034] Specifically, the mixed organic silicon source Si1 in step 1) includes silane and silicate, the silane includes octamethyltrisiloxane and / or trimethylsiloxane, and the silicate is ethyl orthosilicate.

[0035] The present invention also provides an application of the high-silicon Y molecular sieve in a catalytic cracking reaction.

[0036] The beneficial effects of the present invention are:

[0037] 1. In the process of preparing the directing agent, the present invention increases the number of Si-O-Si bonds in the gel by adding a mixed organic silicon source to the synthetic gel, reduces the nucleation barrier, and is conducive to the subsequent crystallization to form a Y molecular sieve with a high silicon-aluminum ratio.

[0038] 2. In the process of preparing the directing agent, the present invention increases the degree of polymerization of the silicon source by controlling the proportion of the alkali source in the gel (the amount of the sodium source Na1 and the sodium source Na2), making it easy to polymerize into large oligomeric silicate ions, forming more crystal nuclei with a high silicon-to-aluminum ratio, which is beneficial to the subsequent crystallization to form a Y molecular sieve with a high silicon-to-aluminum ratio.

[0039] 3. The present invention adds a variety of high-alkalinity template agents to the synthetic gel and directly synthesizes a high-silicon Y molecular sieve with a silicon-aluminum ratio greater than 10.

[0040] Fourth, the molecular sieve synthesis process of the present invention is simple, the synthesized molecular sieve has high crystallinity and purity, high acid strength, and low acid density. When used as a catalytic cracking catalyst, it can improve the reaction activity and service life of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is the XRD pattern of Example 1-2;

[0042] Figure 2 This is the physical adsorption result diagram of Example 1;

[0043] Figure 3 It is a graph showing the NH3-TPD experimental results of Example 1 and Comparative Examples 1-2. DETAILED DESCRIPTION

[0044] The technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] The present invention provides a high-silicon Y molecular sieve, which is obtained by a direct hydrothermal synthesis method. The high-silicon Y molecular sieve has a silicon-aluminum molecular ratio greater than 10 and a specific surface area greater than 900m 2 / g, the total acid content is greater than 0.8mmol / g, and the proportion of strong acid is greater than 45%.

[0046] Here, a method for synthesizing a high-silicon Y molecular sieve is provided, the method comprising:

[0047] 1) Mix aluminum source Al1, sodium source Na1, template agent R1 and deionized water, add mixed organic silicon source Si1, mix and crystallize to obtain a directing agent.

[0048] Specifically, the molar number of aluminum source Al1 and Al2 in step 1) and step 2) is calculated as Al2O3; the molar number of sodium source Na1 and Na2 is calculated as the molar number of Na2O; the molar number of template R1 and R2 is calculated as the molar number of R1 and R2 themselves, respectively; the molar number of silicon source Si1 and silicon source Si2 is calculated as SiO2. In step 1), the aluminum source Al1, the sodium source Na1, the template R1, the deionized water, and the mixed organic silicon source Si1 have the following molar ratios: Na2O / SiO2=0.001-0.015; Na2O / Al2O3=0.05-0.15; H2O / Na2O=1500-3000; R1 / Al2O3=5-7.

[0049] Preferably, Na2O / SiO2=0.01; Na2O / Al2O3=0.1; H2O / Na2O=1800; R1 / Al2O3=6.

[0050] Specifically, the mass ratio of the amount of the directing agent added in step 1) to the SiO2 in the initial gel is 0.05-0.15.

[0051] Specifically, aluminum source Al1, sodium source Na1, template R1 and deionized water are mixed and stirred until clarified.

[0052] Specifically, the mixed organic silicon source Si1 in step 1) includes silane and silicate. Here, the silane includes octamethyltrisiloxane and / or trimethylsiloxane, and the silicate is ethyl orthosilicate. In the process of preparing the directing agent, the present invention increases the number of Si-O-Si bonds in the gel by adding a mixed silicon source to the synthetic gel, reduces the nucleation barrier, and is conducive to the subsequent crystallization to form a Y molecular sieve with a high silicon-aluminum ratio.

[0053] The silicon source Si1 in step 1) comprises silane and silicate, and the mass ratio of silane to silicate is 0.01-0.2 based on SiO2. Preferably, the mass ratio of silane to silicate is 0.1.

[0054] Specifically, in step 1), the crystallization step includes: crystallization at 20-30° C. for 1-5 h under vigorous stirring, crystallization at 40-60° C. for 10-20 h under static conditions, and crystallization at 80-120° C. for 30-80 h under static conditions. Preferably, in step 1), crystallization is carried out at 25° C. for 2 h under vigorous stirring, crystallization is carried out at 50° C. for 15 h under static conditions, and crystallization is carried out at 100° C. for 50 h under static conditions.

[0055] 2) Mixing aluminum source Al2, sodium source Na2, template R2 and deionized water, adding silicon source Si2 to obtain an initial gel, and adding a directing agent to the initial gel to obtain a synthetic gel.

[0056] Specifically, the molar number of aluminum source Al1 and Al2 in step 1) and step 2) is calculated as Al2O3; the molar number of sodium source Na1 and Na2 is calculated as the molar number of Na2O; the molar number of template R1 and R2 is calculated as the molar number of R1 and R2 themselves, respectively; the molar number of silicon source Si1 and silicon source Si2 is calculated as SiO2. In step 2), the aluminum source Al2, the sodium source Na2, the template R2, the deionized water, the silicon source Si2, and the directing agent have the following molar ratios: Na2O / SiO2=0.01-0.2; Na2O / Al2O3=0.1-3; H2O / Na2O=100-180; R2 / Al2O3=3-5.

[0057] Preferably, Na2O / SiO2=0.12; Na2O / Al2O3=1.5; H2O / Na2O=160; R2 / Al2O3=4.

[0058] In one embodiment, during the preparation of the directing agent, the present invention controls the ratio of the intermediate alkali source (the amount of sodium source Na1 and sodium source Na2) in step 1) and step 2), thereby controlling the low alkalinity of the gel and increasing the degree of polymerization of the silicon source, making it easy to polymerize into large oligomeric silicate ions, forming more crystal nuclei with a high silicon-to-aluminum ratio, which is beneficial to the subsequent crystallization to form a Y molecular sieve with a high silicon-to-aluminum ratio.

[0059] Specifically, the aluminum sources Al1 and Al2 in step 1) and step 2) are independently selected from at least one of aluminum isopropoxide, aluminum sec-butoxide, and sodium metaaluminate.

[0060] Specifically, Na1 and Na2 in step 1) and step 2) are independently selected from sodium hydroxide.

[0061] Specifically, the templates R1 and R2 in step 1) and step 2) are independently selected from quaternary ammonium salts, and the quaternary ammonium salts include tetraalkylammonium hydroxide and / or tetrabutylammonium hydroxide. Here, the present invention adds a variety of high-basicity templates (e.g., quaternary ammonium salts) to the synthesis gel, and directly synthesizes a high-silicon Y molecular sieve with a silicon-aluminum ratio greater than 10.

[0062] Specifically, the silicon source Si2 in step 2) is selected from silica sol.

[0063] Specifically, step 2) includes: mixing aluminum source Al2, sodium source Na2, template R2 and deionized water to obtain an initial gel; then adding silicon source Si2, vigorously stirring at 20-30°C for 1-3h, then adding a directing agent, and stirring at 20-30°C for 1-3h.

[0064] 3) Crystallizing, washing, drying and calcining the synthesized gel to obtain a high-silicon Y molecular sieve.

[0065] Specifically, in step 3), the crystallization step includes: crystallization at 100-130° C. for 8-12 days under static conditions. Preferably, in step 3), crystallization is carried out at 120° C. for 10 days under static conditions.

[0066] Specifically, in step 3), deionized water is used for washing until the pH is less than 9.

[0067] Specifically, in step 3), drying can be performed by heating, for example, drying at 100° C. for 12 hours.

[0068] Specifically, in step 3), the calcination temperature is 500-600° C., and the calcination time is 1-3 hours. Preferably, the calcination temperature is 550° C., and the calcination time is 2 hours.

[0069] The present invention also provides an application of the high-silicon Y molecular sieve in a catalytic cracking reaction.

[0070] The present invention will be further described in detail below with reference to specific embodiments.

[0071] Example 1

[0072] This embodiment provides a method for synthesizing a high-silicon Y molecular sieve, comprising:

[0073] Preparation of a directing agent: 4.09 g of aluminum isopropoxide and 0.08 g of sodium hydroxide were dissolved in 50.50 g of tetraethylammonium hydroxide solution, and stirred until clear, which was recorded as a1; 18.76 g of ethyl orthosilicate and 0.79 g of octamethyltrisiloxane were added to a1 in small amounts, and the mixture was vigorously stirred at 25° C. for 2 h, and then transferred to a reactor, and crystallized at 50° C. for 15 h, and then at 100° C. for 50 h, to obtain a directing agent;

[0074] Synthesis of high-silicon Y-type molecular sieve: 0.54g of sodium aluminate and 0.54g of sodium hydroxide are dissolved in 14.22g of water, and 13.88g of tetraalkylammonium hydroxide is added and stirred until clarified, which is recorded as b1; the b1 mixed solution is slowly added to 20g of 30% silica sol under stirring, and after vigorous stirring at 25°C for 2h, 7.55g of directing agent is added, and after stirring at 25°C for 2h, the mixture is transferred to a reactor; after crystallization at 120°C for 9 days, the mixture is cooled to room temperature, washed with deionized water until pH <9, dried at 100°C for 12h, and calcined at 550°C for 2h to obtain the high-silicon Y molecular sieve HSY-A1 of Example 1.

[0075] Example 2

[0076] This embodiment provides a method for synthesizing a high-silicon Y molecular sieve, comprising:

[0077] Preparation of a directing agent: dissolve 2.08 g of aluminum sec-butoxide and 0.08 g of sodium hydroxide in 50.50 g of tetraethylammonium hydroxide solution, stir until clear, and record as a2; add 18.23 g of ethyl orthosilicate and 0.92 g of trimethylsiloxane to a2 in small amounts, stir vigorously at 25°C for 2 h, transfer to a reactor, crystallize at 50°C for 15 h, and then crystallize at 100°C for 50 h to obtain a directing agent;

[0078] Synthesis of high-silicon Y-type molecular sieve: 0.54g of sodium aluminate and 0.54g of sodium hydroxide are dissolved in 14.22g of water, and then 12.96g of tetrabutylammonium hydroxide is added and stirred until clarified, which is recorded as b2; the b2 mixed solution is slowly added to 20g of 30% silica sol under stirring, and after vigorous stirring at 25°C for 2h, 7.57g of directing agent is added, and after stirring at 25°C for 2h, the mixture is transferred to a reactor; after crystallization at 120°C for 9 days, the mixture is cooled to room temperature, washed with deionized water until pH <9, dried at 100°C for 12h, and calcined at 550°C for 2h to obtain the high-silicon Y molecular sieve HSY-A2 of Example 2.

[0079] Comparative Example 1:

[0080] This comparative example provides a method for synthesizing a molecular sieve, comprising:

[0081] Preparation of a directing agent: 2.15 g of sodium aluminate and 5.17 g of sodium hydroxide were dissolved in 9.62 g of deionized water, stirred until clear and cooled, recorded as c1; 29.10 g of water glass was slowly added to c1 under stirring, stirred at 25° C. for 2 h, and then transferred to a reactor, and crystallized at 30° C. for 15 h to obtain a directing agent;

[0082] Synthesis of high-silicon Y-type molecular sieve: 3.59g of sodium aluminate and 4.01g of sodium hydroxide were dissolved in 37.56g of deionized water, stirred until clarified and cooled, recorded as c2; the mixed solution of c2 was slowly added to 25g of 30% silica sol under stirring, and 9.09g of directing agent was added after vigorous stirring at 25°C for 2h. After stirring at 25°C for 2h, the mixture was transferred to a reactor; after crystallization at 100°C for 2 days, it was cooled to room temperature, washed with deionized water to pH <9, dried at 100°C for 12h, and calcined at 550°C for 2h to obtain the high-silicon Y molecular sieve HSY-B1 of comparative example 1.

[0083] Comparative Example 2:

[0084] This comparative example provides a method for synthesizing a molecular sieve, comprising:

[0085] Preparation of a directing agent: 3.02 g of sodium aluminate and 11.29 g of sodium hydroxide were dissolved in 9.73 g of deionized water, stirred until clear and cooled, recorded as d1; 53.79 g of water glass was slowly added to d1 under stirring, stirred at 25° C. for 2 h, and then transferred to a reactor, and crystallized at 30° C. for 12 h to obtain a directing agent;

[0086] Synthesis of high-silicon Y-type molecular sieve: 6.01g of sodium aluminate, 1.02g of sodium hydroxide and 1.63g of trimethylsiloxane are dissolved in 26.05g of deionized water, stirred until clear and cooled, recorded as d2; the mixed solution of d2 is slowly added to 10.68g of C-type silica gel under stirring, and 22.16g of directing agent is added after vigorous stirring at 25°C for 2h, and the mixture is transferred to a reactor after stirring at 25°C for 2h; after crystallization at 100°C for 20h, it is cooled to room temperature, washed with deionized water to pH <9, dried at 100°C for 12h, and calcined at 550°C for 2h to obtain the high-silicon Y molecular sieve HSY-B2 of comparative example 2.

[0087] In order to illustrate the effect of the high-silicon Y molecular sieve provided by the present application, the following experiment was conducted: XRD, physical adsorption and NH3-TPD analysis were performed on the high-silicon Y molecular sieves synthesized in Example 1-2 and Comparative Example 1-2, and the results were as follows:

[0088]

[0089]

[0090] Table 1 Comparison of high silicon Y molecular sieves of Example 1-2 and Comparative Example 1-2

[0091] From Table 1 and Figure 1-3 It can be seen that the synthesis method in the embodiment of the present application can directly synthesize the molecular sieve to obtain a silicon-aluminum molecular ratio greater than 10 and a specific surface area greater than 900m 2 / g, the total acid content is greater than 0.8mmol / g, and the strong acid accounts for more than 45% of the high silicon Y molecular sieve.

[0092] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-silicon Y molecular sieve, characterized in that: The high-silicon Y molecular sieve is obtained by a direct hydrothermal synthesis method. The high-silicon Y molecular sieve has a silicon-aluminum molecular ratio greater than 10 and a specific surface area greater than 900m 2 / g, the total acid content is greater than 0.8mmol / g, and the proportion of strong acid is greater than 45%.

2. The method for synthesizing high-silicon Y molecular sieve according to claim 1, characterized in that: The synthesis method comprises: 1) mixing aluminum source Al1, sodium source Na1, template agent R1 and deionized water, adding mixed organic silicon source Si1, mixing and crystallizing to obtain a directing agent; 2) mixing aluminum source Al2, sodium source Na2, template agent R2 and deionized water, adding silicon source Si2 to obtain an initial gel, and adding a directing agent to the initial gel to obtain a synthetic gel; 3) Crystallizing, washing, drying and calcining the synthesized gel to obtain a high-silicon Y molecular sieve.

3. The synthesis method according to claim 2, characterized in that The molar numbers of the aluminum sources Al1 and Al2 in step 1) and step 2) are calculated as Al2O3; the molar numbers of the sodium sources Na1 and Na2 are calculated as Na2O; the molar numbers of the templates R1 and R2 are calculated as the molar numbers of R1 and R2 themselves, respectively; the molar numbers of the silicon sources Si1 and Si2 are calculated as SiO2; In step 1), the aluminum source Al1, the sodium source Na1, the template R1, the deionized water, and the mixed organic silicon source Si1 have the following molar ratio: Na2O / SiO2=0.001-0.015; Na2O / Al2O3=0.05-0.15; H2O / Na2O=1500-3000; R1 / Al2O3=5-7; In step 2), the aluminum source Al2, the sodium source Na2, the template R2, the deionized water, the silicon source Si2, and the directing agent have the following molar ratio: Na2O / SiO2=0.01-0.2; Na2O / Al2O3=0.1-3; H2O / Na2O=100-180; R2 / Al2O3=3-5; The mass ratio of the amount of the directing agent added in step 1) to the SiO2 in the initial gel is 0.05-0.15; The silicon source Si1 in step 1) includes silane and silicate, and the mass ratio of silane and silicate is 0.01-0.2 based on SiO2.

4. The synthesis method according to claim 2, characterized in that In step 1), the crystallization step includes: Crystallize at 20-30°C for 1-5h under vigorous stirring, at 40-60°C for 10-20h under static conditions, and at 80-120°C for 30-80h under static conditions; Preferably, in step 1), crystallization is carried out at 25° C. for 2 h under vigorous stirring, at 50° C. for 15 h under static conditions, and at 100° C. for 50 h under static conditions.

5. The synthesis method according to claim 2, characterized in that In step 3), the crystallization step includes: Crystallization at 100-130°C for 8-12 days under static conditions; Preferably, in step 3), crystallization is carried out at 120° C. for 10 days under static conditions.

6. The synthesis method according to claim 2, characterized in that The aluminum sources Al1 and Al2 in step 1) and step 2) are independently selected from at least one of aluminum isopropoxide, aluminum sec-butoxide, and sodium metaaluminate.

7. The synthesis method according to claim 2, characterized in that Na1 and Na2 in step 1) and step 2) are independently selected from sodium hydroxide.

8. The synthesis method according to claim 2, characterized in that The templates R1 and R2 in step 1) and step 2) are independently selected from quaternary ammonium salts, and the quaternary ammonium salts include tetraalkylammonium hydroxide and / or tetrabutylammonium hydroxide.

9. The synthesis method according to claim 2, characterized in that: The mixed organic silicon source Si1 in step 1) comprises silane and silicate, wherein the silane comprises octamethyltrisiloxane and / or trimethylsiloxane, and the silicate is ethyl orthosilicate.

10. Use of the high-silicon Y molecular sieve according to claim 1 in catalytic cracking reactions.

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