A ssz-39 molecular sieve, a preparation method therefor and an application thereof

Abstract

The application provides a SSZ-39 molecular sieve and a preparation method and application thereof. The preparation method comprises the following steps: mixing a silicon source, an aluminum source, an alkali source, an organic template agent and water, aging, and obtaining a gel; stirring, crystallizing, filtering, washing and calcining the gel, and obtaining the SSZ-39 molecular sieve; wherein, the aluminum source comprises 0-50% of a first aluminum source, 50%-100% of a second aluminum source and 0-45% of a third aluminum source, based on 100% of the total mass of the aluminum source. The application further provides the SSZ-39 molecular sieve obtained by the above preparation method. The application further provides a DeNOx reaction catalyst comprising the above SSZ-39 molecular sieve and a DeNOx reaction method using the DeNOx reaction catalyst. The SSZ-39 molecular sieve provided by the application has high catalytic activity in an aggregated form and can be used for high space velocity DeNOx reaction.

Description

Technical Field

[0001] This invention relates to the field of molecular sieve technology, and in particular to an SSZ-39 molecular sieve, its preparation method, and its application. Background Technology

[0002] SSZ-39 molecular sieve is a molecular sieve with an AEI topology. It consists of AlO4 and SiO4 tetrahedra connected end-to-end by oxygen atoms, forming a secondary structural unit (SBU) of double six-membered rings. Adjacent layers of these double six-membered rings rotate 180° around the z-axis and are arranged in a staggered pattern. The double six-membered rings are connected by four-membered rings to form an AEI cage (an asymmetric pear-shaped cage) with an eight-membered ring structure and a three-dimensional channel structure. The channel size is... Due to its ordered pore structure, high specific surface area, good hydrothermal stability, numerous surface proton acid centers, and excellent cation exchangeability, SSZ-39 molecular sieve has demonstrated excellent performance in industrial catalytic processes such as NH3- selective catalytic reduction (NH3-SCR) and methanol-to-olefins (MTO) in recent years.

[0003] Conventionally, the hydrothermal synthesis of SSZ-39 molecular sieves generally produces samples with good dispersibility and short crystal aggregates, resulting in short reaction contact times, especially at high space velocities. Therefore, there is a need to develop zeolites with longer residence times in high-space velocities. Increasing the synthesized crystal size is a common method, but synthesizing large-grain zeolites often means extending the crystallization time. However, large-particle zeolite aggregates offer significant advantages in coating, with lower slurry viscosity, higher solids content, and stronger coatings. Therefore, considering production cost, reactivity, and coating effect, there is an urgent need to develop an efficient synthesis method for SSZ-39 molecular sieves with a longer diffusion path. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide an SSZ-39 molecular sieve, its preparation method, and its applications. The SSZ-39 molecular sieve provided by this invention exhibits an aggregated morphology, high catalytic activity, and can be used in high-space-velocity DeNOx reactions.

[0005] To achieve the above objectives, the present invention provides a method for preparing SSZ-39 molecular sieve. The method includes: mixing a silicon source, an aluminum source, an alkali source, an organic template agent, and water; aging the mixture to obtain a gel; stirring the gel, crystallizing it, filtering and washing it, and calcining it to obtain the SSZ-39 molecular sieve; wherein, based on the total mass of the aluminum source being 100%, the aluminum source includes a first aluminum source of 0-50% by mass, a second aluminum source of 50%-100% by mass, and a third aluminum source of 0-45% by mass. The first aluminum source includes an aluminum-containing molecular sieve, the second aluminum source includes an aluminum-containing mineral, and the third aluminum source includes one or more combinations of aluminum oxides, aluminum hydroxides, and aluminum salts.

[0006] In the above preparation method, by using a single aluminum source (second aluminum source), two aluminum sources (first aluminum source and second aluminum source), or three aluminum sources (first aluminum source, second aluminum source and third aluminum source) to participate in the reaction together, the formation of SSZ-39 molecular sieve aggregates and the particle size of SSZ-39 molecular sieve can be promoted.

[0007] According to a specific embodiment of the present invention, taking the total mass of the aluminum source as 100%, the aluminum source may include a second aluminum source with a mass of 100%; or, the aluminum source may include a first aluminum source with a mass greater than 0% and less than or equal to 50%, and a second aluminum source with a mass greater than or equal to 50% and less than 100%; or, the aluminum source may further include a first aluminum source with a mass greater than 0% and less than 50%, a second aluminum source with a mass greater than or equal to 50% and less than 100%, and a third aluminum source with a mass greater than 0% and less than or equal to 45%.

[0008] Furthermore, the aggregation degree of SSZ-39 molecular sieves can be adjusted by changing the ratio between two or three aluminum sources. In specific implementations, the aluminum-containing minerals used as the second aluminum source have a significant impact on the aggregation degree of SSZ-39 molecular sieves. In some implementations, the aggregation degree of SSZ-39 molecular sieves increases as the ratio of the second aluminum source to the first aluminum source (or the first and third aluminum sources) increases.

[0009] According to a specific embodiment of the present invention, the present invention does not impose any special restrictions on the silicon-to-aluminum ratio of the aluminum-containing molecular sieve used as the first aluminum source. The first aluminum source may be one or a combination of two or more of the following: USY molecular sieve, NaY molecular sieve, NH4Y molecular sieve, ZSM-5 molecular sieve, and Beta molecular sieve.

[0010] According to a specific embodiment of the present invention, with the total mass of the aluminum source being 100%, the mass of the first aluminum source can be further controlled to be 10%-40%.

[0011] According to a specific embodiment of the present invention, the second aluminum source may include one or a combination of two or more of boehmite, kaolin, bentonite, and rettore. Further, the second aluminum source preferably includes one or a combination of two or more of boehmite, kaolin, and bentonite.

[0012] According to a specific embodiment of the present invention, with the total mass of the aluminum source being 100%, the mass of the second aluminum source can be further controlled to be greater than or equal to 60% and less than 100%.

[0013] According to specific embodiments of the present invention, the third aluminum source may include one or a combination of two or more of sodium aluminate, alumina, aluminum hydroxide, boehmite, and aluminum isopropoxide. Further, the third aluminum source preferably includes one or a combination of two or more of alumina, boehmite, and aluminum hydroxide. In some specific embodiments, the alumina may be added in the form of aluminum sol.

[0014] According to a specific embodiment of the present invention, with the total mass of the aluminum source being 100%, the mass of the third aluminum source can be further controlled to be 0%-30%.

[0015] According to a specific embodiment of the present invention, taking the total mass of the aluminum source as 100%, the aluminum source may include a first aluminum source with a mass of 10%-40%, a second aluminum source with a mass of greater than or equal to 60% and less than 100%, and a third aluminum source with a mass of 0%-30%.

[0016] According to specific embodiments of the present invention, the silicon source may include one or more of the following: silicon dioxide, silicates, orthosilicates, water glass, and silicon powder. In some specific embodiments, the silicon dioxide may be added in the form of silica sol, silica gel, etc.; the water glass may be solid water glass, liquid water glass, etc. When the silicon source includes two or more components, there are no special restrictions on the proportions between the components.

[0017] In some specific implementations, the silicon source may specifically include one or more of silica sol, silica gel, and water glass (preferably solid water glass).

[0018] According to a specific embodiment of the present invention, the alkali source may include one or a combination of two or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, etc., for example, sodium hydroxide may be used as the alkali source.

[0019] According to a specific embodiment of the present invention, the organic template agent may include piperidine derivative template agents and / or phosphine derivative template agents, etc.

[0020] According to a specific embodiment of the present invention, the phosphine derivative template agent may include tetraethylphosphine hydroxide, etc.

[0021] According to a specific embodiment of the present invention, the piperidine derivative template agent may include one or more combinations of compounds capable of providing the following ions: N,N-diethyl-2,6-dimethylpiperidine ion, 3,5-dimethyl-N,N-dimethylpiperidine ion, N,N-diethyl-2-ethylpiperidine ion, N-ethyl-N-propyl-2,6-dimethylpiperidine ion, N-methyl-N-ethyl-2,6-dimethylpiperidine ion, N-methyl-N-ethyl-2-ethylpiperidine ion, 2,5-dimethyl-N,N-diethylpyrrole ion, 2,6-dimethyl-N,N-dimethylpiperidine ion, 2-ethyl-N,N-dimethylpiperidine ion, 2,2,6,6-tetramethyl-N-methyl-N-ethylpiperidine ion, 2,2,6,6-tetramethyl-N,N-dimethylpiperidine ion, N,N-dimethyl-N,N-bicyclononane ion, etc. In some specific implementations, compounds capable of providing the above ions typically include salts and / or bases of the above ions.

[0022] In some specific embodiments, the piperidine derivative template agent may specifically include one or more of the following: compounds capable of providing N,N-dimethyl-N,N-bicyclononane ions, N,N-diethyl-2,6-dimethylhydropiperidine, and 3,5-dimethyl-N,N-dimethylhydropiperidine.

[0023] According to a specific embodiment of the present invention, the chemical composition of the gel generally satisfies the following molar ratio range: SiO2 / Al2O3 = 5-180; OH - / SiO2 ≤ 1; H2O / SiO2 = 3-80; R / SiO2 ≤ 0.5, where R is the number of moles of the organic template agent;

[0024] In some specific embodiments, the chemical composition of the gel may further satisfy the following molar ratio range: SiO2 / Al2O3 = 5-30; OH - / SiO2 ≤ 0.5; H2O / SiO2 = 5-40; R / SiO2 ≤ 0.2.

[0025] According to a specific embodiment of the present invention, the aging temperature is generally controlled from room temperature to 100°C, and the aging time is generally controlled from 0.1h to 100h, for example, 0.5h to 50h.

[0026] According to a specific embodiment of the present invention, the stirring time for the aged gel is generally controlled to be 0h-3h, specifically 0.5h-1.5h. In some specific embodiments, the stirring can be in the form of rotation.

[0027] According to specific embodiments of the present invention, the crystallization temperature is generally controlled at 120℃-210℃, and the crystallization time is 38h-120h, for example 48h-100h. In some specific embodiments, the crystallization process can be carried out while stirring.

[0028] According to a specific embodiment of the present invention, the roasting temperature is generally controlled at 500℃-600℃, and the roasting time is generally controlled at 2h-6h.

[0029] According to a specific embodiment of the present invention, the above preparation method may specifically include:

[0030] 1. Mix silicon source, aluminum source, organic template agent and water, and age at room temperature to 100℃ for 0.1h-100h to obtain a gel. The chemical composition of the gel meets the following molar ratio range: SiO2 / Al2O3=5-180; OH - / SiO2 ≤ 1; H2O / SiO2 = 3-80; R / SiO2 ≤ 0.5, where R is the number of moles of the organic template agent;

[0031] Wherein, taking the total mass of aluminum source as 100%, the aluminum source includes a first aluminum source of 0-50% by mass, a second aluminum source of 50%-100% by mass, and a third aluminum source of 0-45% by mass; the first aluminum source includes aluminum-containing molecular sieves, the second aluminum source includes aluminum-containing minerals, and the third aluminum source includes one or more combinations of aluminum oxides, aluminum hydroxides, and aluminum salts;

[0032] 2. Stir the gel obtained in step 1 for 0-3 hours, crystallize at 120℃-210℃ for 38-120 hours, filter and wash, and calcine at 500℃-600℃ for 2-6 hours to obtain the SSZ-39 molecular sieve.

[0033] The present invention also provides an SSZ-39 molecular sieve, which is obtained by the above preparation method.

[0034] According to a specific embodiment of the present invention, the SSZ-39 molecular sieve contains SSZ-39 molecular sieve aggregates, that is, there is an aggregated form of SSZ-39 molecular sieve. The aggregate refers to a structure in which multiple small SSZ-39 molecular sieve crystals are aggregated into a larger crystal particle, but the size of the aggregate will be stable within a certain range (specifically, the radial size can reach a certain range), and will not aggregate indefinitely.

[0035] According to a specific embodiment of the present invention, the radial dimension of the SSZ-39 molecular sieve aggregate can reach 5μm-60μm, for example, it can be 5μm-40μm, 5μm-35μm, 10μm-30μm, etc.

[0036] According to a specific embodiment of the present invention, even in the presence of aggregates, the overall specific surface area of ​​the SSZ-39 molecular sieve remains comparable to that of a conventional SSZ-39 molecular sieve. In some specific embodiments, the specific surface area of ​​the SSZ-39 molecular sieve is 710 m². 2 ·g -1 -760m 2 ·g -1 .

[0037] According to a specific embodiment of the present invention, the crystallinity of the SSZ-39 molecular sieve can reach 90%-96%.

[0038] The present invention further provides a DeNOx reaction catalyst comprising the above-mentioned SSZ-39 molecular sieve.

[0039] This invention also provides a DeNOx reaction method, wherein the catalyst used in the DeNOx reaction method includes the aforementioned DeNOx reaction catalyst, and the volume hourly space velocity of the DeNOx reaction method is generally controlled at 80,000-400,000 h⁻¹. -1 (e.g., 240000h) -1 In some specific embodiments, the SSZ-39 molecular sieve of the present invention can be used as a DeNOx reaction catalyst for catalytic volume space velocities of 80,000-400,000 h⁻¹. -1 The DeNOx reaction.

[0040] The beneficial effects of this invention are as follows: The preparation method provided by this invention can obtain aggregated SSZ-39 molecular sieves. This method is simple, low-cost, and suitable for industrial production. The SSZ-39 molecular sieve provided by this invention has good coating effect, a long mass diffusion path, and high catalytic activity, and can be applied to high-space-velocity DeNOx reactions. Attached Figure Description

[0041] Figure 1 The image shows the SEM image of the SSZ-39 molecular sieve from Example 1.

[0042] Figure 2 This is a SEM image of the SSZ-39 molecular sieve from Example 2.

[0043] Figure 3 This is a SEM image of the SSZ-39 molecular sieve from Example 3.

[0044] Figure 4 This is a SEM image of the SSZ-39 molecular sieve from Example 4.

[0045] Figure 5 This is a SEM image of the SSZ-39 molecular sieve from Example 5.

[0046] Figure 6 The image shows the SEM image of the SSZ-39 molecular sieve in Comparative Example 1.

[0047] Figure 7 The image shows the SEM image of SSZ-39 molecular sieve in Comparative Example 2.

[0048] Figure 8 The image shows the SEM image of SSZ-39 molecular sieve in Comparative Example 3.

[0049] Figure 9 The XRD patterns are of SSZ-39 molecular sieves from Examples 1 to 5 and Comparative Examples 1 to 3. Detailed Implementation

[0050] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0051] Example 1

[0052] This embodiment provides a method for preparing SSZ-39 molecular sieve, including:

[0053] 1. Sodium hydroxide, pure water, silica sol with a concentration of 40 wt% and a concentration of 25 wt% of 3,5-dimethyl-N,N-dimethylhydropiperidine aqueous solution, USY molecular sieve, aluminum hydroxide, boehmite, and boehmite were thoroughly mixed and aged at room temperature for 1 hour to obtain a gel with the following molar ratio:

[0054] SiO2 / Al2O3 = 60, wherein the mass ratio of USY molecular sieve, aluminum hydroxide, boehmite and boehmite is 10:20:10:60;

[0055] R / SiO2 = 0.10, where R is the template agent, which in this example is 3,5-dimethyl-N,N-dimethylhydropiperidine;

[0056] OH - / SiO2=0.7,

[0057] H2O / SiO2 = 20.

[0058] 2. The gel from step 1 was placed in an autoclave and stirred at room temperature for 0.5 hours; then heated to 155°C and crystallized for 50 hours to obtain the crystallized product.

[0059] 3. Cool the crystallized product to below 40℃, filter, wash, dry the solid sample, and calcine at 550℃ for 4 hours to obtain SSZ-39 molecular sieve.

[0060] Figure 1This is a SEM image of the SSZ-39 molecular sieve sample from this embodiment. Figure 1 It can be seen that the molecular sieve particles exhibit significant aggregation. Measurements show that the radial size of the particle aggregates in this sample is approximately 20 μm–35 μm. See XRD results for details. Figure 9 XRD measurements showed that the crystallinity of the sample was approximately 96%. Adsorption tests revealed that the specific surface area of ​​the sample was 760 m². 2 ·g -1 .

[0061] Example 2

[0062] This embodiment provides a method for preparing SSZ-39 molecular sieve, including:

[0063] 1. Sodium hydroxide, pure water, silica sol with a silica concentration of 40 wt%, solid water glass, tetraethylphosphine hydroxide, ZSM-5 molecular sieve, kaolin, and pseudoboehmite were thoroughly mixed and aged at room temperature for 1 hour to obtain a gel with the following molar ratio:

[0064] The ratio of SiO2 / Al2O3 is 30, where the mass ratio of silica sol and solid water glass is 30:70, and the mass ratio of ZSM-5 molecular sieve, kaolin, and pseudoboehmite is 5:50:45.

[0065] R / SiO2 = 0.11, where R is the template agent, which in this example is tetraethylphosphine hydroxide;

[0066] OH - / SiO2=0.6;

[0067] H2O / SiO2 = 80;

[0068] 2. The gel from step 1 is placed in an autoclave and crystallized at 160°C for 45 hours to obtain the crystallized product.

[0069] 3. Cool the crystallized product to below 40℃, filter, wash, dry the solid sample, and calcine at 550℃ for 4 hours to obtain SSZ-39 molecular sieve.

[0070] Figure 2 This is a SEM image of the SSZ-39 molecular sieve sample from this embodiment. Figure 2 It can be seen that the molecular sieve particles exhibit significant aggregation. Measurements show that the radial size of the particle aggregates in this sample is approximately 15 μm–35 μm. See XRD results below. Figure 9 XRD measurements showed that the crystallinity of the sample was approximately 95%. Adsorption tests determined that the specific surface area of ​​the sample was 749 m². 2 ·g -1 .

[0071] Example 3

[0072] This embodiment provides a method for preparing SSZ-39 molecular sieve, including:

[0073] 1. Potassium hydroxide, pure water, silica gel, solid water glass, 25wt% N,N-diethyl-2,6-dimethylhydropiperidine, NaY molecular sieve, and bentonite were thoroughly mixed and aged at room temperature for 1 hour to obtain a synthetic gel with the following molar ratio:

[0074] The SiO2 / Al2O3 ratio is 45, where the mass ratio of silica gel to solid water glass is 10:90, and the mass ratio of NaY molecular sieve to bentonite is 40:60.

[0075] R / SiO2 = 0.12, where R is the template agent, which in this embodiment is N,N-diethyl-2,6-dimethylhydropiperidine;

[0076] OH - / SiO2=0.6;

[0077] H2O / SiO2 = 40.

[0078] 2. Place the gel into an autoclave, stir at room temperature for 0.5 hours, and then heat to 175°C to crystallize for 30 hours.

[0079] 3. Cool the crystallized product to below 40℃, filter, wash, dry the solid sample, and calcine at 550℃ for 4 hours to obtain SSZ-39 molecular sieve.

[0080] Figure 3 This is a SEM image of the SSZ-39 molecular sieve sample from this embodiment. Figure 3 It can be seen that the molecular sieve particles exhibit significant aggregation. Measurements show that the radial size of the particle aggregates in this sample is approximately 15 μm–30 μm. See XRD results for details. Figure 9 XRD measurements showed that the crystallinity of the sample was approximately 90%. Adsorption tests revealed that the specific surface area of ​​the sample was 750 m². 2 ·g -1 .

[0081] Example 4

[0082] This embodiment provides a method for preparing SSZ-39 molecular sieve, including:

[0083] 1. Potassium hydroxide, pure water, silica sol with a concentration of 40 wt% silica, 3,5-dimethyl-N,N-dimethylhydropiperidine with a concentration of 25 wt%, kaolin, and bentonite were thoroughly mixed and aged at room temperature for 1 hour to obtain a gel with the following molar ratio:

[0084] SiO2 / Al2O3 = 45, wherein the mass ratio of kaolin to bentonite is 80:20;

[0085] R / SiO2 = 0.11, where R is the template agent, which in this example is 3,5-dimethyl-N,N-dimethylhydropiperidine;

[0086] OH - / SiO2=0.8,

[0087] H2O / SiO2 = 35.

[0088] 2. Place the gel into an autoclave, stir at room temperature for 0.5 hours, and then heat to 175°C to crystallize for 40 hours.

[0089] 3. Cool the crystallized product to below 40℃, filter, wash, dry the solid sample, and calcine at 550℃ for 4 hours to obtain SSZ-39 molecular sieve.

[0090] Figure 4 This is a SEM image of the SSZ-39 molecular sieve sample from this embodiment. Figure 4 It can be seen that the molecular sieve particles exhibit significant aggregation. Measurements show that the radial size of the particle aggregates in this sample is approximately 15 μm–30 μm. See XRD results for details. Figure 9 XRD measurements showed that the crystallinity of the sample was approximately 95%. Adsorption tests revealed that the specific surface area of ​​the sample was 710 m². 2 ·g -1 .

[0091] Example 5

[0092] This embodiment provides a method for preparing SSZ-39 molecular sieve, including:

[0093] 1. Potassium hydroxide, pure water, silica sol with a concentration of 40 wt%, 3,5-dimethyl-N,N-dimethylhydropiperidine with a concentration of 25 wt%, Beta molecular sieve, kaolin, and pseudoboehmite were thoroughly mixed and aged at room temperature for 1 hour to obtain a gel with the following molar ratio:

[0094] SiO2 / Al2O3 = 50, wherein the mass ratio of Beta molecular sieve, kaolin, and pseudoboehmite is 10:60:30;

[0095] R / SiO2 = 0.15, where R is the template agent, which in this example is 3,5-dimethyl-N,N-dimethylhydropiperidine;

[0096] OH - / SiO2=0.7,

[0097] H2O / SiO2 = 50.

[0098] 2. Place the gel into an autoclave, stir at room temperature for 0.5 hours, and then heat to 180°C to crystallize for 40 hours.

[0099] 3. Cool the crystallized product to below 40℃, filter, wash, dry the solid sample, and calcine at 550℃ for 4 hours to obtain SSZ-39 molecular sieve.

[0100] Figure 5 This is a SEM image of the SSZ-39 molecular sieve sample from this embodiment. Figure 5 It can be seen that the molecular sieve particles exhibit significant aggregation. Measurements show that the radial size of the particle aggregates in this sample is approximately 20 μm–60 μm. See XRD results for details. Figure 9 XRD measurements showed that the crystallinity of the sample was approximately 90%. Adsorption tests revealed that the specific surface area of ​​the sample was 720 m². 2 ·g -1 .

[0101] The XRD characterization results of the SSZ-39 molecular sieve samples in Examples 1 to 5 showed only the crystal form corresponding to SSZ-39 molecular sieve and no impurities, indicating that the above samples are pure SSZ-39 molecular sieves.

[0102] Comparative Example 1

[0103] This comparative example provides a method for preparing SSZ-39 molecular sieve, including:

[0104] 1. Sodium hydroxide, pure water, silica sol with a concentration of 40 wt% silica, an aqueous solution of 3,5-dimethyl-N,N-dimethylhydropiperidine with a concentration of 25 wt%, and Beta molecular sieve were thoroughly mixed and aged at room temperature for 1 hour to obtain a gel with the following molar ratio:

[0105] SiO2 / Al2O3 = 45,

[0106] R / SiO2 = 0.15, where R is the template agent, which in this comparative example is 3,5-dimethyl-N,N-dimethylhydropiperidine;

[0107] OH - / SiO2=0.6,

[0108] H2O / SiO2 = 35.

[0109] 2. Place the gel into an autoclave, stir at room temperature for 0.5 hours, and then heat to 160°C to crystallize for 50 hours.

[0110] 3. Cool the crystallized product to below 40℃, filter, wash, dry the solid sample, and calcine at 550℃ for 4 hours to obtain SSZ-39 molecular sieve.

[0111] Figure 6 This is a SEM image of the SSZ-39 molecular sieve sample used in this comparative example. The particle size of this sample was measured to be approximately 1.5 μm–4 μm. XRD results are shown below. Figure 9 XRD measurements showed that the crystallinity of the sample was approximately 90%. Adsorption tests determined that the specific surface area of ​​the sample was 736 ± 10 m². 2 ·g -1 .

[0112] Comparative Example 2

[0113] This comparative example provides a method for preparing SSZ-39 molecular sieve, including:

[0114] 1. Sodium hydroxide, pure water, silica sol with a concentration of 40 wt% silica, an aqueous solution of 3,5-dimethyl-N,N-dimethylhydropiperidine with a concentration of 25 wt%, USY molecular sieve, and boehmite were thoroughly mixed and aged at room temperature for 1 hour to obtain a gel with the following molar ratio:

[0115] SiO2 / Al2O3 = 45, wherein the mass ratio of USY molecular sieve to boehmite is 80:20;

[0116] R / SiO2 = 0.10, where R is the template agent, which in this comparative example is 3,5-dimethyl-N,N-dimethylhydropiperidine;

[0117] OH - / SiO2=0.5,

[0118] H2O / SiO2 = 20.

[0119] 2. Place the gel into an autoclave, stir at room temperature for 0.5 hours, and then heat to 160°C to crystallize for 50 hours.

[0120] 3. Cool the crystallized product to below 40°C, filter, wash, dry the solid sample, and calcine to obtain SSZ-39 zeolite.

[0121] Figure 7 This is a SEM image of the SSZ-39 molecular sieve sample from this embodiment. The particle size of this sample was measured to be approximately 1 μm-3 μm. XRD results are shown below. Figure 9 XRD measurements showed that the crystallinity of the sample was approximately 90%. Adsorption tests determined that the specific surface area of ​​the sample was 746 m². 2 ·g -1 .

[0122] Comparative Example 3

[0123] This comparative example provides a method for preparing SSZ-39 molecular sieve, including:

[0124] 1. Sodium hydroxide, pure water, silica sol with a concentration of 40 wt% silica, an aqueous solution of 3,5-dimethyl-N,N-dimethylhydropiperidine with a concentration of 25 wt%, USY molecular sieve, and aluminum hydroxide were thoroughly mixed and aged at room temperature for 1 hour to obtain a gel with the following molar ratio:

[0125] SiO2 / Al2O3 = 60, wherein the mass ratio of USY molecular sieve to aluminum hydroxide is 70:30;

[0126] R / SiO2 = 0.15, where R is the template agent, which in this comparative example is 3,5-dimethyl-N,N-dimethylhydropiperidine;

[0127] OH - / SiO2=0.9,

[0128] H2O / SiO2 = 60.

[0129] 2. Place the gel into an autoclave, stir at room temperature for 0.5 hours, and then heat to 160°C to crystallize for 50 hours.

[0130] 3. Cool the crystallized product to below 40°C, filter, wash, dry the solid sample, and calcine to obtain SSZ-39 zeolite.

[0131] Figure 8 This is a SEM image of the SSZ-39 molecular sieve sample from this embodiment. The particle size of this sample was measured to be approximately 2.5 μm–3.5 μm. XRD results are shown below. Figure 9 XRD measurements showed that the crystallinity of the sample was approximately 90%. Adsorption tests determined that the specific surface area of ​​the sample was 755 m². 2 ·g -1 .

[0132] Test Example 1

[0133] This test example provides NH3-SCR reaction performance testing for SSZ-39 molecular sieve samples prepared in Examples 1 to 5 and Comparative Examples 1 to 3. Specific test methods include:

[0134] 1. Molecular sieve ammonium exchange: The SSZ-39 molecular sieves prepared in Examples 1 to 5 and Comparative Examples 1 to 3 were mixed with ammonium nitrate: molecular sieve: water at a mass ratio of 1:1:10. The pH was adjusted to 8-8.5 using ammonia water. The mixture was exchanged at 90°C for 1 hour with stirring. After filtration, washing, drying, and calcination at 550°C for 4 hours, the process was repeated three times until the alkali content (OH-) in the molecular sieve was reduced. - (less than 0.1%)

[0135] 2. Copper loading on molecular sieve: Copper acetate with a loading of 5% CuO on the molecular sieve is dissolved in 50 times its weight of water. The molecular sieve that has undergone ammonium exchange is added under stirring. The pH is adjusted to 8-8.5 with ammonia water. The mixture is filtered, washed, dried, and calcined at 550℃ for 4 hours to obtain Cu-SSZ-39 composite molecular sieve that has undergone ammonium exchange and is loaded with Cu.

[0136] 3. The Cu-SSZ-39 composite molecular sieve was pressed into tablets, pulverized, and sieved. It was then hydrothermally aged at 650℃ for 100 hours in a 10% H₂O + 90% nitrogen atmosphere. 0.5 g of a 40-60 mesh Cu-SSZ-39 molecular sieve sample was used for the NH₃-SCR reaction. The composition of the reaction mixture was: 1000 ppm NO, 1100 ppm NH₃, 10 vol% O₂, and 10 vol% H₂O, with N₂ as the equilibrium gas. The volume hourly space velocity (VHSV) was 240,000 h⁻¹. -1 The reaction temperature was 200℃-600℃, and the NOx concentration (NO, NO2, and N2O) in the exhaust gas was detected online using an MKS infrared gas analyzer. The test results are shown in Table 1.

[0137] 4. NO x Conversion rate (conversion rate of nitrogen oxides) is defined as:

[0138]

[0139] Among them, [NO] 进口 To determine the concentration of NO in the reaction mixture, [NO] 出口 [NO2] represents the concentration of NO in the exhaust gas. 出口 [N2O] represents the concentration of NO2 in the exhaust gas. 出口 This represents the concentration of N2O in the exhaust gas.

[0140] Table 1. Conversion rate of nitrogen oxides in the reaction mixture

[0141] 150℃，％ 350℃，％ 550℃，％ Example 1 57 96 95 Example 2 58 94 95 Example 3 59 95 96 Example 4 59 93 93 Example 5 59 94 94 Commercial zeolite 51 92 90 Comparative Example 1 53 94 90 Comparative Example 2 53 93 90 Comparative Example 3 52 92 91

[0142] The commercial zeolites in Table 1 are SSZ-39 molecular sieve products with a particle size of 2-3.5 μm, purchased from Zhongchumei Company.

[0143] As can be seen from Table 1, within the temperature range of 150-550℃, the DeNOx activity of the Cu-SSZ-39 molecular sieves corresponding to Examples 1 to 5 of the present invention is higher than that of the Cu-SSZ-39 molecular sieves corresponding to Comparative Examples 1 to 3, or at least comparable. Furthermore, the DeNOx activity of the Cu-SSZ-39 molecular sieves corresponding to Examples 1 to 5 is significantly better than that of commercial zeolites.

[0144] In addition, Figures 1 to 5 and Figures 6 to 8Comparative analysis reveals that the SSZ-39 molecular sieves in all embodiments are aggregated, while the SSZ-39 molecular sieve particles in Comparative Examples 1 to 3 are dispersed. This indicates that aggregated molecular sieves cannot be obtained in the absence of a second aluminum source or when the proportions of each aluminum source exceed the limits defined in this invention. These results demonstrate that the type and proportion of aluminum sources added play a crucial role in the formation of the aggregated state of the SSZ-39 molecular sieve and the activity of the molecular sieve catalyst.

Claims

1. A method of making a SSZ-39 molecular sieve, the method comprising: mixing a silicon source, an aluminum source, a base source, an organic template, and water, aging to obtain a gel; stirring, crystallizing, filtering, washing, and calcining the gel to obtain the SSZ-39 molecular sieve; wherein the aluminum source comprises, based on 100% of the total mass of the aluminum source, greater than 0% and less than or equal to 50% of a first aluminum source, and greater than or equal to 50% and less than 100% of a second aluminum source; or, the aluminum source comprises greater than 0% and less than 50% of a first aluminum source, greater than or equal to 50% and less than 100% of a second aluminum source, and greater than 0% and less than or equal to 45% of a third aluminum source; the first aluminum source comprises an aluminum-containing molecular sieve, the second aluminum source comprises an aluminum-containing mineral, and the third aluminum source comprises one or a combination of two or more of an oxide of aluminum, a hydroxide of aluminum, and a salt of aluminum.

2. The production method according to claim 1, wherein the first aluminum source comprises one or a combination of two or more of a USY molecular sieve, a NaY molecular sieve, an NH4Y molecular sieve, a ZSM-5 molecular sieve, and a Beta molecular sieve.

3. The production method according to claim 1, wherein the first aluminum source comprises, based on 100% of the total mass of the aluminum source, greater than or equal to 10% and less than or equal to 40%.

4. The production method according to claim 1, wherein the second aluminum source comprises one or a combination of two or more of boehmite, kaolin, bentonite, and rectorite.

5. The production method according to claim 4, wherein, the second aluminum source comprises one or a combination of two or more of boehmite, kaolin, and bentonite.

6. The production method according to claim 1, wherein the second aluminum source comprises, based on 100% of the total mass of the aluminum source, greater than or equal to 60% and less than 100%.

7. The production method according to claim 1, wherein the third aluminum source comprises one or a combination of two or more of sodium metaaluminate, alumina, aluminum hydroxide, pseudoboehmite, and aluminum isopropoxide.

8. The production method according to claim 7, wherein the third aluminum source comprises one or a combination of two or more of alumina, pseudoboehmite, and aluminum hydroxide.

9. The production method according to claim 7, wherein the alumina comprises an aluminum sol.

10. The production method according to claim 1, wherein, the third aluminum source comprises, based on 100% of the total mass of the aluminum source, greater than or equal to 0% and less than or equal to 30%.

11. The method of producing according to claim 1, wherein, the silicon source comprises one or a combination of two or more of silica, a silicate, an orthosilicate, water glass, and silicon powder.

12. The method of making according to claim 11, wherein, the silica comprises a silica sol and / or a silica gel.

13. The method of making according to claim 11, wherein, the silicon source comprises one or a combination of two or more of a silica sol, a silica gel, and water glass.

14. The method of producing according to claim 1, wherein, the base source comprises one or a combination of two or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, and barium hydroxide.

15. The method of producing according to claim 1, wherein, the organic template comprises a piperidine derivative template and / or a phosphine derivative template.

16. The method of manufacturing according to claim 15, wherein, the phosphine derivative template comprises tetraethylphosphonium hydroxide.

17. The method of making according to claim 15, wherein, The piperidine derivative template includes one or more than two combinations of the following ions: N,N-diethyl-2,6-dimethylpiperidinium ion, 3,5-dimethyl-N,N- dimethylpiperidinium ion, N,N-diethyl-2-ethylpiperidinium ion, N-ethyl-N-propyl-2,6- dimethylpiperidinium ion, N-methyl-N-ethyl-2,6-dimethylpiperidinium ion, N-methyl-N- ethyl-2-ethylpiperidinium ion, 2,5-dimethyl-N,N-diethylpyrrolidinium ion, 2,6-dimethyl- N,N-dimethylpiperidinium ion, 2-ethyl-N,N-dimethylpiperidinium ion, 2,2,6,6-tetramethyl- N-methyl-N-ethylpiperidinium ion, 2,2,6,6-tetramethyl-N,N-dimethylpiperidinium ion, N,N-dimethyl-N,N-bicyclononane ion.

18. The method of making according to claim 17, wherein, The piperidine derivative template includes one or more than two combinations of the following ions: N,N-diethyl-2,6-dimethylpiperidinium ion, 3,5-dimethyl-N,N- dimethylpiperidinium ion, N,N-diethyl-2-ethylpiperidinium ion, N-ethyl-N-propyl-2,6- dimethylpiperidinium ion, N-methyl-N-ethyl-2,6-dimethylpiperidinium ion, N-methyl-N- ethyl-2-ethylpiperidinium ion, 2,5-dimethyl-N,N-diethylpyrrolidinium ion, 2,6-dimethyl- N,N-dimethylpiperidinium ion, 2-ethyl-N,N-dimethylpiperidinium ion, 2,2,6,6-tetramethyl- N-methyl-N-ethylpiperidinium ion, 2,2,6,6-tetramethyl-N,N-dimethylpiperidinium ion, N,N-dimethyl-N,N-bicyclononane ion.

19. The method of producing according to claim 1, wherein, The chemical composition of the gel satisfies the following molar ratio range: SiO2 / Al2O3 = 5-180; OH - / SiO2 less than or equal to 1; H2O / SiO2 = 3-80; R / SiO2 less than or equal to 0.5, where R is the number of moles of organic template.

20. The method of making according to claim 19, wherein, The chemical composition of the gel satisfies the following molar ratio range: SiO2 / Al2O3 = 5-30; OH - H2O / SiO2 = 5-40; R / SiO2 less than or equal to 0.

2.

21. The method of producing according to claim 1, wherein, The aging temperature is room temperature to 100°C, and the aging time is 0.1 h to 100 h. The crystallization temperature is 120°C to 210°C, and the crystallization time is 38 h to 120 h. The calcination temperature is 500°C to 600°C, and the calcination time is 2 h to 6 h.

22. The method of making according to claim 21, wherein, The aging time is 0.5 h to 50 h.

23. The method of making according to claim 21, wherein, The crystallization time is 48 h to 100 h.

24. A SSZ-39 molecular sieve obtained from the preparation method of any one of claims 1-23.

25. The SSZ-39 molecular sieve of claim 24, wherein, The SSZ-39 molecular sieve contains SSZ-39 molecular sieve aggregates, and the radial size of the SSZ-39 molecular sieve aggregates is 5 μm to 60 μm.

26. The SSZ-39 molecular sieve of claim 25, wherein, The radial size of the SSZ-39 molecular sieve aggregates is 5 μm to 35 μm.

27. The SSZ-39 molecular sieve of claim 25, wherein, The radial size of the SSZ-39 molecular sieve aggregates is 10 μm to 30 μm.

28. The SSZ-39 molecular sieve of claim 24, wherein, The SSZ-39 molecular sieve has a specific surface area of 710 m 2 ·g -1 -760 m 2 ·g -1 ; The crystallinity of the SSZ-39 molecular sieve is 90% to 96%.

29. A DeNOx reaction catalyst comprising the SSZ-39 molecular sieve of any one of claims 24-28.

30. A DeNOx reaction method employing a catalyst comprising the DeNOx reaction catalyst according to claim 29, the DeNOx reaction method having a volume space velocity of 80000 to 400000 h"1. -1 .

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