A method for the synthesis of a silicoaluminous itq-13 zeolitic molecular sieve

Abstract

The application discloses a synthesis method of a silicon-aluminum ITQ-13 zeolite molecular sieve, belongs to the technical field of synthesis of molecular sieves, and comprises the following steps: uniformly mixing a silicon source, an aluminum source, an organic template R, water and seeds, and then placing the mixture in a reaction kettle for crystallization reaction at 170-180 DEG C for 7-12 days; and performing suction filtration and drying on the product to obtain the silicon-aluminum ITQ-13 zeolite molecular sieve. The application provides a new synthesis method, which can be used to synthesize the silicon-aluminum ITQ-13 zeolite molecular sieve without adding HF and Ge, greatly reduces the danger of experiments, and introduces aluminum into the skeleton of the ITQ-13 zeolite molecular sieve without adding germanium, so that the cost of synthesis and the complexity of post-processing operations are greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to a synthesis method of a silicon-aluminum ITQ-13 zeolite molecular sieve, in particular to a method for synthesizing a silicon-aluminum ITQ-13 zeolite molecular sieve by using a template without adding HF, and belongs to the technical field of molecular sieve synthesis. BACKGROUND

[0002] Zeolite molecular sieve materials, including silicon-aluminum molecular sieves, phosphorus-aluminum molecular sieves, etc., have been widely used in the fields of petroleum chemical industry, fine chemicals and environmental protection, etc. Among them, the ITQ-13 zeolite molecular sieve is a silicon-aluminum molecular sieve with a typical ITH topological structure, a three-dimensional 9*10*10 pore system, and is one of the few molecular sieves containing odd-membered ring, and has superior activity and selectivity in the methanol-to-olefins (MTO) reaction.

[0003] However, the traditional ITQ-13 zeolite molecular sieve is usually synthesized under neutral or acidic conditions in the presence of HF. For example, a Chinese patent with publication number CN106698456A discloses a method for synthesizing an aluminum-containing ITQ-13 molecular sieve by a one-step linear polyquaternary ammonium base organic template method. In this method, a silicon source, an aluminum source, a linear polyquaternary ammonium base organic template T, and hydrofluoric acid or ammonium fluoride are mixed, stirred uniformly, and then placed in a reaction kettle for crystallization reaction. The product is filtered and dried to obtain the ITQ-13 zeolite molecular sieve. However, HF is dangerous in use and is not environmentally friendly.

[0004] Corma et al. published in J.Catal (2006, 238, 79–87) introduced germanium (Ge) species to reduce the energy of D4Rs units, successfully synthesized Ge-ITH zeolite by adding Ge under HF-free conditions, but post-treatment was needed to obtain the silicon-aluminum ITQ-13 molecular sieve. The use of Ge not only increases the cost, but also reduces the stability of the zeolite.

[0005] Therefore, it is crucial to synthesize this zeolite without adding HF and Ge, and to develop a new method for synthesizing a silicon-aluminum ITQ-3 zeolite molecular sieve.

[0006] The existing method uses N,N-di(3-fluorobenzyl)-N,N,N,N-tetramethyl-1,6-hexanediammonium cation as a template to synthesize ITQ-13 molecular sieve, but this method can only obtain a full-silicon ITQ-13 molecular sieve, which is used for the Beckmann rearrangement reaction of cyclohexanone oxime. SUMMARY

[0007] The purpose of the present application is to overcome the deficiencies in the prior art and synthesize a silicon-aluminum ITQ-13 zeolite molecular sieve without adding HF and Ge.

[0008] To solve the technical problem, the solution of the present application is:

[0009] A synthesis method of a silicon-aluminum ITQ-13 zeolite molecular sieve, comprising the following steps: uniformly mixing a silicon source, an aluminum source, an organic template R, water and seeds, and then placing the mixture in a reaction kettle for crystallization reaction at 170-180 DEG C for 7-12 days; and then performing suction filtration and drying to obtain the silicon-aluminum ITQ-13 zeolite molecular sieve.

[0010] Further provided are:

[0011] The adding amounts of the silicon source, the aluminum source, the organic template R and the water are controlled to make the molar ratio of SiO2:Al2O3:organic template R:H2O = 1:0.00-0.0025:0.5:2-5.

[0012] The aluminum source is aluminum isopropoxide.

[0013] The silicon source is tetraethyl orthosilicate.

[0014] The water is deionized water.

[0015] The seeds are ITQ-13 molecular sieve seeds.

[0016] The organic template R is prepared by the following method: N,N,N,N-tetramethyl-1,6-hexanediamine and halogenated hydrocarbon are weighed according to the molar ratio of 1:2.2, dissolved in acetonitrile, and reacted at room temperature for 24 hours to obtain white solid; the white solid is dried by suction filtration to obtain the organic template R quaternary ammonium salt; the organic template R quaternary ammonium salt is dissolved in water, and the halogen in the organic template R quaternary ammonium salt is completely exchanged into hydroxyl by using a strong basic anion exchange resin; and the resin is suction filtered to obtain the organic template R solution.

[0017] The crystallization reaction is performed at 175 DEG C for 7 days.

[0018] After the silicon source, the aluminum source, the organic template R and the water are uniformly mixed, dehydration and dealcoholization are performed in an 80 DEG C oven; in order to ensure that the alcohol can be completely removed and does not affect the crystallization of the molecular sieve, the oven drying needs to be performed for more than 12 hours.

[0019] A synthesis method of a silicon-aluminum ITQ-13 zeolite molecular sieve, aluminum isopropoxide as the aluminum source is dissolved in the organic template R solution, and then tetraethyl orthosilicate as the silicon source is added and stirred; after the tetraethyl orthosilicate is completely hydrolyzed, the mixture is weighed and placed in an 80 DEG C oven for dehydration and dealcoholization; in order to ensure that the alcohol can be completely removed and does not affect the crystallization of the molecular sieve, the oven drying needs to be performed for more than 12 hours; the mixture is weighed again to add water to make the H2O / SiO2 molar ratio be 2-5, and then the seeds are uniformly mixed; the gel is transferred to a polytetrafluoroethylene stainless steel reaction kettle, and crystallization is performed at 175 DEG C for 7 days; the product is suction filtered and dried to obtain the product.

[0020] Compared with the prior art, the present application has the beneficial effects that:

[0021] 1. The present application provides a new synthesis method, which can synthesize silicon-aluminum ITQ-13 zeolite molecular sieve without adding HF and Ge, greatly reducing the danger of experiment.

[0022] 2. The present application provides an organic template agent, which can introduce aluminum into the framework of ITQ-13 zeolite molecular sieve without adding germanium, greatly reducing the cost of synthesis and the complexity of post-processing operation.

[0023] The present application will be further described below in combination with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 XRD spectrum of the silicon-aluminum ITQ-13 zeolite molecular sieve product (crystallization is complete) prepared in Example 1 of the present application.

[0025] Figure 2 Scanning electron microscope photo of the silicon-aluminum ITQ-13 zeolite molecular sieve product (crystallization is complete) prepared in Example 1 of the present application.

[0026] Figure 3 XRD spectrum of the silicon-aluminum ITQ-13 zeolite molecular sieve product (amorphous without crystallization) prepared in Example 2 of the present application.

[0027] Figure 4 XRD spectrum of the silicon-aluminum ITQ-13 zeolite molecular sieve product (amorphous without complete crystallization, molecular sieve and amorphous exist simultaneously) prepared in Example 5 of the present application. DETAILED DESCRIPTION

[0028] The present application will be further described in detail below in combination with the accompanying drawings and specific embodiments: the raw materials described in the examples are commercially available or known products, unless otherwise specified.

[0029] The organic template agent R used in the present application is prepared by the following method:

[0030] Preparation of organic template agent R1: N,N,N,N-tetramethyl-1,6-hexanediamine and 3-fluorobenzyl bromide are weighed according to the molar ratio of 1:2.2, dissolved in acetonitrile, and reacted at room temperature for 24 h to obtain white solid. The white solid is extracted and dried to obtain the organic template agent R1 quaternary ammonium salt. The organic template agent R1 quaternary ammonium salt is dissolved in water, and the bromine in the organic template agent R1 quaternary ammonium salt is completely exchanged into hydroxyl group by using strong basic anion exchange resin (IRN-78 Sigma-Aldrich Co., Ltd.). After extracting and filtering the resin, the organic template agent R1 solution is obtained.

[0031] Preparation of organic template R2: N,N,N,N-tetramethyl-1,6-hexanediamine and 4-fluorobenzyl bromide were weighed according to a molar ratio of 1:2.2, dissolved in acetonitrile, and reacted at room temperature for 24 h to obtain a white solid. The white solid was dried by suction filtration to obtain the quaternary ammonium salt of organic template R2. The quaternary ammonium salt of organic template R2 was dissolved in water, and the bromine in the quaternary ammonium salt of organic template R2 was completely exchanged into hydroxyl groups by using a strong basic anion exchange resin (IRN-78, Sigma-Aldrich). After suction filtration of the resin, a solution of organic template R2 was obtained.

[0032] Preparation of organic template R3: N,N,N,N-tetramethyl-1,6-hexanediamine and 3,5-difluorobenzyl bromide were weighed according to a molar ratio of 1:2.2, dissolved in acetonitrile, and reacted at room temperature for 24 h to obtain a white solid. The white solid was dried by suction filtration to obtain the quaternary ammonium salt of organic template R3. The quaternary ammonium salt of organic template R3 was dissolved in water, and the bromine in the quaternary ammonium salt of organic template R3 was completely exchanged into hydroxyl groups by using a strong basic anion exchange resin (IRN-78, Sigma-Aldrich). After suction filtration of the resin, a solution of organic template R3 was obtained.

[0033] Example 1

[0034] In this example, the synthesis of the silicon-aluminum ITQ-13 zeolite molecular sieve was carried out using the organic template R1. The molar ratio of the raw materials was 1.0 SiO2 / 0.0025 Al2O3 / 0.5 organic template R1 / 2 H2O.

[0035] First, 0.0085 g of aluminum isopropoxide was added to 8.33 g of the organic template R1 solution (0.5 mmol / g) for dissolution, followed by the addition of 1.73 g of tetraethyl orthosilicate and stirring for 30 min. After the tetraethyl orthosilicate was completely hydrolyzed, it was weighed and placed in a 80°C oven for dehydration and dealcoholization. To ensure that the alcohol was completely removed and did not affect the crystallization of the molecular sieve, the sample was dried for more than 12 h. The water content was then adjusted to H2O / SiO2=2 (molar ratio), 0.05 g of seed crystals was added and mixed uniformly, and the gel was then transferred to a polytetrafluoroethylene stainless steel reaction kettle. Crystallization was carried out at 175°C for 7 d. The product was suction filtered and dried to obtain the product.

[0036] Product characterization:

[0037] The product prepared in Example 1 was subjected to XRD and scanning electron microscopy analysis, as shown in Figure 1 , Figure 2 Figure 1 The X-ray diffraction analysis showed that the structure of the product was ITQ-13 zeolite molecular sieve, Figure 2 The scanning electron micrograph (SEM) of the ITQ-13 zeolite molecular sieve product showed that the synthesized product was completely crystallized and exhibited a uniform nanosheet structure.​

[0038] In order to explore the influence of different aluminum sources on the performance of molecular sieves, experiments were performed as shown in Examples 2-3.

[0039] Example 2

[0040] In this example, aluminum sulfate octadecahydrate was used as the aluminum source to synthesize the silicon-aluminum ITQ-13 zeolite molecular sieve. The molar ratio of each reaction raw material was: 1.0 SiO2 / 0.0025 Al2O3 / 0.5 organic template R1 / 2 H2O.

[0041] First, 0.0139 g of aluminum sulfate octadecahydrate was added to 8.33 g of an organic template R1 solution (0.5 mmol / g) for dissolution, followed by the addition of 1.73 g of tetraethyl orthosilicate for mixing and stirring for 30 min. After the tetraethyl orthosilicate was fully hydrolyzed, it was weighed and placed in a 80°C oven for dehydration and dealcoholization. To ensure that the alcohol was completely removed and did not affect the crystallization of the molecular sieve, it needed to be dried for more than 12 h. The water content was then supplemented to H2O / SiO2=2 (molar ratio), 0.05 g of seed crystals was added and mixed uniformly, and then the gel was transferred to a polytetrafluoroethylene stainless steel reaction kettle for crystallization at 175°C for 7 d. The product was suction filtered and dried to obtain the product.

[0042] Product characterization:

[0043] The product prepared in Example 2 was subjected to XRD analysis, as shown in Figure 3 Comparing the XRD pattern of the product prepared in Example 1 with that of Example 2, it can be found that the XRD spectrum of the sample after crystallization in Example 2 shows an amorphous state without crystallization, the baseline is not flat, and there is only a small amount of seed crystal peak.

[0044] Example 3

[0045] In this example, aluminum sulfate octadecahydrate was used as the aluminum source to synthesize the silicon-aluminum ITQ-13 zeolite molecular sieve. The molar ratio of each reaction raw material was: 1.0 SiO2 / 0.0025 Al2O3 / 0.5 organic template R1 / 2 H2O.

[0046] First, 0.0139 g of aluminum sulfate octadecahydrate was added to 8.33 g of an organic template R1 solution (0.5 mmol / g) for dissolution, followed by the addition of 1.73 g of tetraethyl orthosilicate for mixing and stirring for 30 min. After the tetraethyl orthosilicate was fully hydrolyzed, it was weighed and placed in a 80°C oven for dehydration and dealcoholization. To ensure that the alcohol was completely removed and did not affect the crystallization of the molecular sieve, it needed to be dried for more than 12 h. The water content was then supplemented to H2O / SiO2=2 (molar ratio), 0.05 g of seed crystals was added and mixed uniformly, and then the gel was transferred to a polytetrafluoroethylene stainless steel reaction kettle for crystallization at 175°C for 7 d. The product was suction filtered and dried to obtain the product.

[0047] The product was analyzed to be in an amorphous state.

[0048] Example 4

[0049] This example mainly discusses the influence of the selection of silicon source on the performance of molecular sieve. Fine silica gel (Si02) is used as the silicon source to synthesize silicon-aluminum ITQ-13 zeolite molecular sieve. The molar ratio of each reaction raw material is: 1.0 Si02 / 0.0025 Al203 / 0.5 organic template R1 / 2 H20.

[0050] First, 0.0085 g of aluminum isopropoxide is added to 8.33 g of organic template R1 solution (0.5 mmol / g) for dissolution, followed by the addition of 0.5 g of fine silica gel (Si02) for mixing and stirring for 30 min. After complete hydrolysis, the mixture is weighed and placed in a 80°C oven for dehydration and dealcoholization, which requires drying for 12 h or more. The water content is supplemented to H20 / Si02=2 (molar ratio) by weighing, 0.05 g of seed crystal is added and mixed uniformly, and then the gel is transferred to a polytetrafluoroethylene stainless steel reaction kettle. Crystallization is carried out at 175°C for 7 d. The product is suction filtered and dried to obtain the product.

[0051] The product is analyzed to be in an amorphous state.

[0052] Example 5

[0053] This example mainly discusses the influence of the dealcoholization process on the performance of molecular sieve. The molar ratio of each reaction raw material is: 1.0 Si02 / 0.0025 Al203 / 0.5 organic template R1 / 2 H20.

[0054] First, 0.0085 g of aluminum isopropoxide is added to 8.33 g of organic template R1 solution (0.5 mmol / g) for dissolution, followed by the addition of 1.73 g of tetraethyl orthosilicate for mixing and stirring for 30 min. After complete hydrolysis of the tetraethyl orthosilicate, the mixture is weighed and placed in a 80°C oven for dehydration (only dried to the specified water content, and the alcohol is not completely removed). 0.05 g of seed crystal is added and mixed uniformly, and then the gel is transferred to a polytetrafluoroethylene stainless steel reaction kettle. Crystallization is carried out at 175°C for 7 d. The product is suction filtered and dried to obtain the product.

[0055] The product prepared in Example 5 is analyzed by XRD, as shown in Figure 4 The XRD spectrum of the sample after crystallization in Example 5 shows that ITQ-13 appears to be crystallized, but not completely crystallized, and ITQ-13 molecular sieve and amorphous coexist.

[0056] Example 6

[0057] This example mainly discusses the influence of the addition of seed crystals on the properties of the molecular sieve, and the molar ratio of the reaction raw materials is: 1.0 SiO2 / 0.0025 Al2O3 / 0.5 organic template R1 / 2 H2O.

[0058] First, 0.0085 g of aluminum isopropoxide is added to 8.33 g of organic template R1 solution (0.5 mmol / g) for dissolution, then 1.73 g of tetraethyl silicate is added and stirred for 30 min. After the tetraethyl silicate is fully hydrolyzed, it is weighed and placed in an 80°C oven for dehydration and dealcoholization. To ensure that the alcohol is completely removed and does not affect the crystallization of the molecular sieve, it needs to be dried for more than 12 h. Again, the water content is supplemented to H2O / SiO2=2 (molar ratio), and then transferred to a polytetrafluoroethylene stainless steel reaction kettle. Crystallization is carried out at 175°C for 7 d, the product is suction filtered, and dried to obtain the product.

[0059] The product is analyzed to be in an amorphous state without crystallization.

[0060] Example 7

[0061] This example mainly discusses the influence of the timing of the addition of seed crystals on the properties of the molecular sieve, and the molar ratio of the reaction raw materials is: 1.0 SiO2 / 0.0025 Al2O3 / 0.5 organic template R1 / 2 H2O.

[0062] First, 0.0085 g of aluminum isopropoxide is added to 8.33 g of organic template R1 solution (0.5 mmol / g) for dissolution, then 1.73 g of tetraethyl silicate is added and stirred for 30 min. After the tetraethyl silicate is fully hydrolyzed, it is weighed and placed in an 80°C oven for dehydration and dealcoholization. To ensure that the alcohol is completely removed and does not affect the crystallization of the molecular sieve, it needs to be dried for more than 12 h. Again, the water content is supplemented to H2O / SiO2=2 (molar ratio), and then transferred to a polytetrafluoroethylene stainless steel reaction kettle. Crystallization is carried out at 175°C for 7 d, the product is suction filtered, and dried to obtain the product.

[0063] The product is analyzed to be in an amorphous state without crystallization.

[0064] Example 8

[0065] This example mainly discusses the influence of the amount of aluminum isopropoxide added on the properties of the molecular sieve, and the molar ratio of the reaction raw materials is: 1.0 SiO2 / 0.00125 Al2O3 / 0.5 organic template R1 / 2 H2O.

[0066] First, 0.00425 g of isopropyl alcohol aluminum was added to 8.33 g of an organic template R1 solution (0.5 mmol / g) for dissolution, then 1.73 g of tetraethyl silicate was added and stirred for 30 min. After the tetraethyl silicate was fully hydrolyzed, it was weighed and placed in an 80°C oven for dehydration and dealcoholization. To ensure that the alcohol was completely removed and did not affect the crystallization of the molecular sieve, it was dried for more than 12 h. The water content was supplemented again, H2O / SiO2=2 (molar ratio), 0.05 g of seed crystals was added and mixed uniformly, then the gel was transferred to a polytetrafluoroethylene stainless steel reaction kettle, and crystallized at 175°C for 7 d. The product was suction filtered and dried to obtain the product.

[0067] The product was analyzed to be completely crystallized and had good crystallinity.

[0068] Example 9

[0069] This example mainly discusses the effect of H2O / SiO2 ratio on the performance of the molecular sieve. The molar ratio of each reaction raw material is: 1.0 SiO2 / 0.0025 Al2O3 / 0.5 organic template R1 / 5 H2O.

[0070] First, 0.0085 g of isopropyl alcohol aluminum was added to 8.33 g of an organic template R1 solution (0.5 mmol / g) for dissolution, then 1.73 g of tetraethyl silicate was added and stirred for 30 min. After the tetraethyl silicate was fully hydrolyzed, it was weighed and placed in an 80°C oven for dehydration and dealcoholization. To ensure that the alcohol was completely removed and did not affect the crystallization of the molecular sieve, it was dried for more than 12 h. The water content was supplemented again, H2O / SiO2=5 (molar ratio), 0.05 g of seed crystals was added and mixed uniformly, then the gel was transferred to a polytetrafluoroethylene stainless steel reaction kettle, and crystallized at 175°C for 7 d. The product was suction filtered and dried to obtain the product.

[0071] The product was analyzed to be completely crystallized and had good crystallinity.

[0072] Example 10

[0073] This example mainly discusses the effect of H2O / SiO2 ratio on the performance of the molecular sieve. The molar ratio of each reaction raw material is: 1.0 SiO2 / 0.0025 Al2O3 / 0.5 organic template R1 / 8 H2O.

[0074] First, 0.0085 g of isopropyl alcohol aluminum was added to 8.33 g of an organic template R1 solution (0.5 mmol / g) for dissolution, then 1.73 g of tetraethyl silicate was added and stirred for 30 min. After the tetraethyl silicate was fully hydrolyzed, it was weighed and placed in an 80°C oven for dehydration and dealcoholization. To ensure that the alcohol was completely removed and did not affect the crystallization of the molecular sieve, it was dried for more than 12 h. The water content was then supplemented to H2O / SiO2=8 (molar ratio), 0.05 g of seeds was added and mixed uniformly, and then the gel was transferred to a polytetrafluoroethylene stainless steel reaction kettle. Crystallization was carried out at 175°C for 7 d. The product was suction filtered and dried to obtain the product.

[0075] The product was analyzed to be in an amorphous state without crystallization.

[0076] Example 11

[0077] This example mainly discusses the effect of crystallization time on the performance of the molecular sieve. The molar ratio of each reaction raw material is: 1.0 SiO2 / 0.0025 Al2O3 / 0.5 organic template R1 / 2 H2O.

[0078] First, 0.0085 g of isopropyl alcohol aluminum was added to 8.33 g of an organic template R1 solution (0.5 mmol / g) for dissolution, then 1.73 g of tetraethyl silicate was added and stirred for 30 min. After the tetraethyl silicate was fully hydrolyzed, it was weighed and placed in an 80°C oven for dehydration and dealcoholization. To ensure that the alcohol was completely removed and did not affect the crystallization of the molecular sieve, it was dried for more than 12 h. The water content was then supplemented to H2O / SiO2=8 (molar ratio), 0.05 g of seeds was added and mixed uniformly, and then the gel was transferred to a polytetrafluoroethylene stainless steel reaction kettle. Crystallization was carried out at 175°C for 7 d. The product was suction filtered and dried to obtain the product.

[0079] The product was analyzed to be in an amorphous state without crystallization.

[0080] Example 12

[0081] This example mainly discusses the effect of crystallization time on the performance of the molecular sieve. The molar ratio of each reaction raw material is: 1.0 SiO2 / 0.0025 Al2O3 / 0.5 organic template R1 / 2 H2O.

[0082] First, 0.0085 g of aluminum isopropoxide was added to 8.33 g of the organic template R1 solution (0.5 mmol / g) for dissolution, then 1.73 g of tetraethyl silicate was added and stirred for 30 min. After the tetraethyl silicate was fully hydrolyzed, it was weighed and placed in an 80°C oven for dehydration and dealcoholization. To ensure that the alcohol was completely removed and did not affect the crystallization of the molecular sieve, it was dried for more than 12 h. The water content was then supplemented to H2O / SiO2=2 (molar ratio), 0.05 g of seed crystals was added and mixed uniformly, and then the gel was transferred to a polytetrafluoroethylene stainless steel reaction kettle. Crystallization was carried out at 175°C for 12 d. The product was suction filtered and dried to obtain the product.

[0083] The addition amount of each reaction raw material was controlled so that the molar ratio was in the range of 1.0 SiO2 / 0.0025 Al2O3 / 0.5R / 2H2O. The product had good crystallinity.

[0084] The product was analyzed and found to be completely crystallized and had good crystallinity.

[0085] Example 13

[0086] This example mainly discusses the effect of different templates on the performance of the molecular sieve. The organic template R2 was used to direct the synthesis of the silicon-aluminum ITQ-13 zeolite molecular sieve. The molar ratio of each reaction raw material was 1.0 SiO2 / 0.0025 Al2O3 / 0.5 organic template R2 / 2 H2O.

[0087] First, 0.0085 g of aluminum isopropoxide was added to 8.33 g of the organic template R2 solution (0.5 mmol / g) for dissolution, then 1.73 g of tetraethyl silicate was added and stirred for 30 min. After the tetraethyl silicate was fully hydrolyzed, it was weighed and placed in an 80°C oven for dehydration and dealcoholization. To ensure that the alcohol was completely removed and did not affect the crystallization of the molecular sieve, it was dried for more than 12 h. The water content was then supplemented to H2O / SiO2=2 (molar ratio), 0.05 g of seed crystals was added and mixed uniformly, and then the gel was transferred to a polytetrafluoroethylene stainless steel reaction kettle. Crystallization was carried out at 175°C for 7 d. The product was suction filtered and dried to obtain the product.

[0088] The product was analyzed and found to be completely crystallized and had good crystallinity.

[0089] Example 14

[0090] This example mainly discusses the effect of different templates on the performance of the molecular sieve. The organic template R3 was used to direct the synthesis of the silicon-aluminum ITQ-13 zeolite molecular sieve. The molar ratio of each reaction raw material was 1.0 SiO2 / 0.0025 Al2O3 / 0.5 organic template R3 / 2 H2O.

[0091] First, 0.0085 g of isopropyl alcohol aluminum was added to 8.33 g of an organic template R3 solution (0.5 mmol / g) for dissolution, then 1.73 g of tetraethyl silicate was mixed and stirred for 30 min, after the tetraethyl silicate was fully hydrolyzed, it was weighed and placed in an 80°C oven for dehydration and dealcoholization. To ensure that the alcohol is completely removed and does not affect the crystallization of the molecular sieve, it needs to be dried for more than 12 h. Again, supplement the water H2O / SiO2=2 (molar ratio), add 0.05 g of seed crystals and mix uniformly, then transfer the gel to a polytetrafluoroethylene stainless steel reaction kettle, and crystallize at 175°C for 7 d. The product is suction filtered and dried to obtain the product.

[0092] The product was analyzed by XRD and was found to be completely crystallized and had good crystallinity.

[0093] Comparative Example 1

[0094] In this example, the organic template R1 was used to direct the synthesis of the all-silicon ITQ-13 zeolite molecular sieve, and the addition amount of each reaction raw material was controlled so that the molar ratio was in the range of 1.0 SiO2 / 0.0 Al2O3 / 0.5 organic template R1 / 2 H2O,

[0095] First, 8.33 g of an organic template R1 solution (0.5 mmol / g) and 1.73 g of tetraethyl silicate were mixed and stirred for 10 min, the excess water was baked off, and the gel was transferred to a polytetrafluoroethylene stainless steel reaction kettle, and crystallized at 175°C for 7 d. The product was suction filtered and dried to obtain the product.

[0096] The product was analyzed and was found to be completely crystallized and had good crystallinity.

[0097] Analysis:

[0098] The ITQ-13 zeolite molecular sieves prepared under different process conditions in Examples 1-14 and Comparative Example 1 were analyzed, and the corresponding product state statistics are shown in Table 1.

[0099] Table 1

[0100] Serial number Silicon source Aluminum source Al2O3 / Si [H2O / Si] Crystallization time Other conditions Product state Comparative Example 1 tetraethyl orthosilicate / 0 2 7d ITQ-13 (crystallized completely) Example 1 tetraethyl orthosilicate aluminum isopropoxide 0.0025 2 7d ITQ-13 (crystallized completely) Example 2 tetraethyl orthosilicate aluminum sulfate octadecahydrate 0.0025 2 7d amorphous (not crystallized) Example 3 tetraethyl orthosilicate aluminum hydroxide 0.0025 2 7d amorphous (not crystallized) Example 4 Fine silica (Si02) aluminum isopropoxide 0.0025 2 7d amorphous (not crystallized) Example 5 tetraethyl orthosilicate aluminum isopropoxide 0.0025 2 7d de-alcoholization not complete ITQ-13 + amorphous (not crystallized completely) Example 6 tetraethyl orthosilicate aluminum isopropoxide 0.0025 2 7d without seed crystal amorphous (not crystallized) Example 7 tetraethyl orthosilicate aluminum isopropoxide 0.0025 2 7d seed crystal added before water removal ITQ-13 + amorphous (not crystallized completely) Example 8 tetraethyl orthosilicate aluminum isopropoxide 0.0125 2 7d ITQ-13 (crystallized completely) Example 9 tetraethyl orthosilicate aluminum isopropoxide 0.0025 5 7d ITQ-13 (crystallized completely) Example 10 tetraethyl orthosilicate aluminum isopropoxide 0.0025 8 7d amorphous (not crystallized) Example 11 tetraethyl orthosilicate aluminum isopropoxide 0.0025 2 4d ITQ-13 + amorphous (not crystallized completely) Example 12 tetraethyl orthosilicate aluminum isopropoxide 0.0025 2 12d ITQ-13 (crystallized completely) Example 13 tetraethyl orthosilicate aluminum isopropoxide 0.0025 2 7d organic template R2 ITQ-13 (crystallized completely) Example 14 tetraethyl orthosilicate aluminum isopropoxide 0.0025 2 7d organic template R3 ITQ-13 (crystallized completely) .

[0101] As shown in Table 1:

[0102] (1) Effect of silicon source and aluminum source on synthesis of molecular sieve

[0103] By comparing Example 1-4, it is shown that the selection of the silicon source and the aluminum source in the synthesis scheme is crucial; when tetraethyl orthosilicate is used as the silicon source, and aluminum hydroxide and aluminum sulfate octadecahydrate are used as the aluminum source, the ITQ-13 molecular sieve cannot be completely crystallized; when aluminum isopropoxide is used as the aluminum source, and fine silica gel is used as the silicon source, the ITQ-13 molecular sieve cannot be completely crystallized. The above shows that the selection of the silicon source and the aluminum source is crucial; when aluminum isopropoxide and tetraethyl orthosilicate are used as the raw materials, there is a hydrolysis process in the initial stirring, and the amorphous silica-aluminum gel formed by the sufficient mixing of the silicon source and the aluminum source in the hydrolysis process is helpful for the crystallization of the molecular sieve in the later stage, so that the completely crystallized silica-aluminum ITQ-13 molecular sieve is obtained.

[0104] (2) Effect of dealcoholization treatment on synthesis of molecular sieve

[0105] By comparing Example 1 and Example 5, it is shown that whether the dealcoholization is complete during the synthesis process will have an important influence on the crystallization result; if the ethanol produced by the hydrolysis of tetraethyl orthosilicate and aluminum isopropoxide is not completely removed, it may have an influence on the crystallization process of the molecular sieve, and this step is very crucial.

[0106] (3) Effect of addition of seed crystals and timing on synthesis of molecular sieve

[0107] By comparing Example 6 and Example 7, it is shown that the addition of seed crystals and the timing also have an influence on the crystallization result; if the seed crystals are not added, the completely crystallized silica-aluminum ITQ-13 molecular sieve cannot be obtained; if the seed crystals are added before the high-temperature dehydration treatment, the seed crystals may be partially dissolved in the high-temperature alkaline solution environment, which also leads to the failure to obtain the completely crystallized silica-aluminum ITQ-13 molecular sieve.

[0108] (4) Effect of crystallization time on synthesis of molecular sieve

[0109] By comparing Example 11-12, it can be seen that the crystallization time has a great influence on the synthesis of the molecular sieve; if the crystallization time is not enough, the silica-aluminum ITQ-13 molecular sieve cannot be completely crystallized, and generally, the crystallization time of more than 7 days is preferred.

[0110] (5) Preparation of all-silicon ITQ-13 molecular sieve and silica-aluminum ITQ-13 molecular sieve

[0111] By comparing Comparative Example 1, it can be seen that the process conditions for preparing the all-silicon ITQ-13 molecular sieve and the silica-aluminum ITQ-13 molecular sieve are not the same; the all-silicon ITQ-13 molecular sieve does not need to add seed crystals, while under the condition of not adding HF, there are several key factors for synthesizing the silica-aluminum ITQ-13 molecular sieve; not only the addition of seed crystals and the timing, but also the selection of the silicon source and the aluminum source, and the dealcoholization treatment, all of which are the key factors for whether the silica-aluminum ITQ-13 molecular sieve is completely crystallized.

[0112] The above merely describes several embodiments of the present application, and does not limit the present application in any form. Although the present application has been disclosed with the above preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed structure and technical content without departing from the technical solution of the present application, and equivalent embodiments with equivalent changes are equivalent. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present application without departing from the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A method for the synthesis of a silicoaluminic ITQ-13 zeolitic molecular sieve, characterized in that, The method comprises the following steps: uniformly mixing a silicon source, an aluminum source, an organic template R, water and seeds, and then placing the mixture in a reaction kettle for crystallization reaction at 170-180 DEG C for 7-12 days; and then performing suction filtration and drying to obtain the silicon-aluminum ITQ-13 zeolite molecular sieve. The aluminum source is aluminum isopropoxide. The silicon source is tetraethyl orthosilicate. The seeds are ITQ-13 molecular sieve seeds. The organic template R is prepared by the following method: N,N,N,N-tetramethyl-1,6-hexanediamine and halogenated hydrocarbon are weighed according to a molar ratio of 1:2.2, dissolved in acetonitrile, and reacted at room temperature for 24 hours to obtain white solid; the white solid is dried by suction filtration to obtain the organic template R quaternary ammonium salt; the organic template R quaternary ammonium salt is dissolved in water, and the halogen in the organic template R quaternary ammonium salt is completely exchanged into hydroxyl by using a strong basic anion exchange resin; and the resin is suction filtered to obtain the organic template R solution. The aluminum source aluminum isopropoxide is added to the organic template R solution for dissolution, and then the silicon source tetraethyl orthosilicate is added for mixing and stirring; after the tetraethyl orthosilicate is fully hydrolyzed, dehydration and dealcoholization treatment are performed; then the seeds are uniformly mixed, and the mixture is placed in a reaction kettle for crystallization reaction.

2. The method of synthesizing a silico-alumina ITQ-13 zeolite molecular sieve according to claim 1, characterized in that: The addition amounts of the silicon source, the aluminum source, the organic template R and water are controlled to make the molar ratio of SiO2:Al2O3:organic template R:H2O = 1:0.00-0.0025:0.5:2-5.

3. The method of synthesizing a silico-alumina ITQ-13 zeolite molecular sieve according to claim 1, characterized in that: The water is deionized water.

4. The method of claim 1, wherein the method is characterized by: The crystallization reaction is performed at 175 DEG C for 7 days.

5. The method of claim 1, wherein the method is characterized by: The aluminum source aluminum isopropoxide is added to the organic template R solution for dissolution, and then the silicon source tetraethyl orthosilicate is added for mixing and stirring; after the tetraethyl orthosilicate is fully hydrolyzed, dehydration and dealcoholization treatment are performed; then the seeds are uniformly mixed, and the mixture is placed in a reaction kettle for crystallization reaction. The addition amounts of the silicon source, the aluminum source, the organic template R and water are controlled to make the molar ratio of SiO2:Al2O3:organic template R:H2O = 1:0.00-0.0025:0.5:2-5. The water is deionized water. The crystallization reaction is performed at 175 DEG C for 7 days. The aluminum source aluminum isopropoxide is added to the organic template R solution for dissolution, and then the silicon source tetraethyl orthosilicate is added for mixing and stirring; after the tetraethyl orthosilicate is fully hydrolyzed, dehydration and dealcoholization treatment are performed; then the seeds are uniformly mixed, and the mixture is placed in a reaction kettle for crystallization reaction.

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