Abc-6 family series small-pore silicoaluminate molecular sieve and preparation method thereof
Patent Information
- Application Number
- CN202211599116.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-12-12
- Publication Date
- 2026-10-09
- Estimated Expiration
- 2042-12-12
AI Technical Summary
[0004]文献中报道了由ABC-6家族的SOD硅铝分子筛作为晶体生长基底置于CAN或CHA硅铝分子筛的合成初始凝胶中，SOD晶粒表面生长出CAN或CHA晶粒，研究的主要内容为共生分子筛异质外延生长界面连接情况，但并未实现由SOD硅铝分子筛完全转化为纯相的CAN或CHA硅铝分子筛
[0068] The beneficial effects that this application can produce include:
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Figure CN118183787B_ABST
Abstract
Description
Technical Field
[0001] This application relates to an ABC-6 family series of small-pore silica-alumina molecular sieves and a rapid preparation method thereof, belonging to the field of molecular sieve synthesis. Background Technology
[0002] Molecular sieves are a class of crystalline materials with regularly arranged channels or cage-like structures. The framework structure of a molecular sieve consists of four-coordinated TO4 atoms (T = Si, Al, P, B, Ge, etc.) connected by shared oxygen atoms at common vertices, forming cavities with channels of varying sizes and shapes. Based on the pore openings defined by T atoms, they can be further classified into micropore (8T), mesopore (10T), macropore (12T), and even ultra-macropore (≥12T) molecular sieves. Among them, 8-membered ring molecular sieves, due to their regular channel structure and pore size distribution, large specific surface area, inherent shape-selective sieving effect, excellent stability, and controllable polarity, have been widely used in gas separation, ion exchange, and catalysis. In particular, 8-membered ring micropore molecular sieves with large cage-like structures, such as ERI (eri cage), LEV (lev cage), CHA (cha cage), and AFX (aft cage), are widely used in methanol-to-olefins (MTO) and selective catalytic reduction of NO. x The silica-alumina molecular sieve SSZ-13(CHA) and ERI have received increasing attention from industry and academia due to their applications in areas such as SCR and gas separation. Among them, SSZ-13(CHA) and ERI have been commercialized and are widely used in adsorption separation and catalysis.
[0003] Currently, FAU-type silica-alumina molecular sieves with different silica-to-alumina ratios are frequently used as raw materials for synthesizing small-pore silica-alumina molecular sieves. Furthermore, some small-pore molecular sieves can only be synthesized through this zeolite interconversion process. For example, the small-pore silica-alumina molecular sieve SSZ-52 (SFW), composed of GME and unique SFW cages, exhibits excellent selective catalytic reduction (SCR) performance and can only be synthesized using FAU-type silica-alumina molecular sieves as raw materials. Although this synthesis method can accelerate crystallization to some extent, thereby shortening the crystallization time, the final crystalline product still needs to be obtained within several days.
[0004] The literature reports the use of ABC-6 family SOD aluminosilicate molecular sieves as crystal growth substrates placed in the initial gel for synthesis of CAN or CHA aluminosilicate molecular sieves. CAN or CHA crystals grow on the surface of the SOD crystals. The main focus of the study is the interface connection of the heteroepitaxial growth of the symbiotic molecular sieves, but the complete transformation of SOD aluminosilicate molecular sieves into pure-phase CAN or CHA aluminosilicate molecular sieves has not been achieved. (TWTatsuya Okubo, Jacques) et al., Angew.Chem.Int.Ed., 2001, 40, No. 6.; A SYToru Wakihara, Kumiko Iezumi, and Tatsuya Okubo, J.Am.Chem.Soc, 2003, 125, 12388-12389.) Summary of the Invention
[0005] According to the first aspect of this application, an ABC-6 family series of small-pore silica-alumina molecular sieves is provided.
[0006] An ABC-6 family series of small-pore silica-alumina molecular sieves, the anhydrous chemical composition of which is shown in Formula I:
[0007] k'M·m'R·(Si x Al y O2 Formula I
[0008] Where M represents the inorganic cation Na + and / or K + ;
[0009] R stands for template agent;
[0010] k' represents per mole (Si) x Al y The number of moles of inorganic cations corresponding to O2, k' = 0.01 to 0.20;
[0011] m' represents per mole (Si) x Al y The molar number of O2 corresponding to template agent R, m' = 0.01~0.10;
[0012] x and y represent the mole fractions of Si and Al, respectively, with ranges of x = 0.5 to 0.9 and y = 0.1 to 0.5, and x + y = 1.
[0013] Optionally, k' is selected from any value or a range between 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, and 0.20.
[0014] Optionally, m' is selected from any value among 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, or a range of values between any two.
[0015] Optionally, x is selected from any value of 0.5, 0.6, 0.7, 0.8, 0.9 or a range of values between any two.
[0016] Optionally, y is selected from any value of 0.1, 0.2, 0.3, 0.4, 0.5 or a range of values between any two.
[0017] Optionally, the molecular sieve includes one of the following framework structures: ERI, SWY, LEV, AFX, and PTT.
[0018] Optionally, the molecular sieve has one of the following framework structures: ERI, SWY, LEV, AFX, and PTT.
[0019] Optionally, the template agent R is selected from 1,4-bis(N-trimethyl)butane ammonium hydroxide, 1,5-bis(N-trimethyl)pentane ammonium hydroxide, 1,4-bis(N-triethyl)butane ammonium hydroxide, 1,5-bis(N-triethyl)pentane ammonium hydroxide, 1,6-bis(N-triethyl)hexane ammonium hydroxide, 1,8-bis(N-triethyl)octane ammonium hydroxide, 1,6-bis(N-trimethyl)hexane ammonium hydroxide, 1,6-(1,4-diazabicyclo[]hydroxide]hydroxide, and 1,4-bis(N-trimethyl)hexane ammonium hydroxide. At least one of the following: [2.2.2]octane]hexylammonium salt, 1,8-hydroxy(1,4-diazabicyclo[2.2.2]octane)octylammonium salt, 1,10-hydroxy(1,4-diazabicyclo[2.2.2]octane)decylammonium salt, mepiquat chloride, 1,4-hydroxy(1,4-diazabicyclo[2.2.2]octane)butylammonium salt, 5-hydroxyazospirol[4.4]ammonium salt, and 1,12-hydroxy(1,4-diazabicyclo[2.2.2]octane)dodecylammonium salt.
[0020] Optionally, x / y = 3.5 to 7.0.
[0021] Optionally, x / y is selected from any value of 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7 or a range of values between any two.
[0022] Optionally, the molecular sieve has an ERI-type framework structure, its morphology is rod-shaped, and the grain size is 200-600 nm;
[0023] Optionally, the molecular sieve has an SWY-type framework structure, its morphology is rod-shaped, and the grain size is 300 nm to 2 μm;
[0024] Optionally, the molecular sieve has a LEV-type framework structure with a rhombic cubic morphology and a grain size of 200 nm to 2 μm.
[0025] Optionally, the molecular sieve has an AFX-type framework structure, its morphology is spherical, and the grain size is 200 nm to 2 μm;
[0026] Optionally, the molecular sieve has a PTT-type framework structure with a cubic polyhedron morphology and a grain size of 100 nm to 2 μm.
[0027] According to a second aspect of this application, a method for preparing the aforementioned molecular sieve is provided. This method utilizes SOD aluminosilicate molecular sieves from the ABC-6 family as both silicon and aluminum sources to synthesize various small-pore aluminosilicate molecular sieves with different topological structures from the ABC-6 family. These methods can synthesize small-pore aluminosilicate molecular sieves, including but not limited to those with ERI, SWY, LEV, AFX, and PTT framework structures. This effectively accelerates the formation of small-pore aluminosilicate molecular sieves from the ABC-6 family and significantly shortens their crystallization time.
[0028] The method for preparing the molecular sieve described above includes the following steps:
[0029] (S1) Add the silica-alumina molecular sieve with SOD-type framework structure to a mixture containing water, template agent R, and inorganic base MOH and mix evenly to obtain an initial gel mixture;
[0030] (S2) The initial gel mixture obtained in step (S1) is placed in a sealed container and crystallized to obtain the ABC-6 family series of small-pore silica-alumina molecular sieves.
[0031] Optionally, the molar ratio of each raw material in the initial gel mixture is as follows:
[0032] Al2O3 / SiO2 = 0.01–0.10;
[0033] MOH / SiO2 = 0.1–1.0;
[0034] H2O / SiO2 = 5~50;
[0035] R / SiO2 = 0.01–1.0;
[0036] Wherein, SiO2 is measured by the number of moles of SiO2 contained in the silica-alumina molecular sieve with an SOD-type framework structure;
[0037] Al2O3 is expressed in moles as the number of Al2O3 contained in a silica-alumina molecular sieve with an SOD-type framework structure.
[0038] Inorganic bases (MOH) are measured by their own molar number;
[0039] H2O is measured by its own number of moles;
[0040] The template agent R is measured in moles of itself.
[0041] Optionally, the molar ratio of Al2O3 / SiO2 is selected from any value of 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10 or any range between the two.
[0042] Optionally, the molar ratio of MOH / SiO2 is selected from any value or a range between 0.1, 0.2, 0.25, 0.28, 0.30, 0.35, 0.40, 0.45, 0.50, 0.60, 0.70, 0.80, 0.90, and 1.0.
[0043] Optionally, the molar ratio of H2O / SiO2 is selected from any value of 5, 6, 7, 9, 13, 18, 20, 24, 30, 36, 40, 44, 48, 50 or any range between the two.
[0044] Optionally, the molar ratio of R / SiO2 is selected from any value among 0.005, 0.02, 0.05, 0.10, 0.20, 0.30, 0.35, 0.40, 0.45, 0.50, 0.60, 0.70, 0.80, 0.90, and 1.0, or a range between any two.
[0045] Optionally, the silica-alumina ratio of the silica-alumina molecular sieve with the SOD-type framework structure is 5 to 100.
[0046] Optionally, the silica-alumina ratio of the silica-alumina molecular sieve with the SOD-type framework structure is selected from any value or a range between 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100.
[0047] Optionally, the particle size of the silica-alumina molecular sieve with an SOD-type framework structure is 4–10 μm.
[0048] Optionally, the particle size of the silica-alumina molecular sieve with an SOD-type framework structure is 5–7 μm.
[0049] Optionally, the particle size of the silica-alumina molecular sieve with the SOD-type framework structure is selected from any value of 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm or any value between the two.
[0050] This method uses dense SOD-type silica-alumina molecular sieves of the ABC-6 family as silicon and aluminum sources to rapidly prepare a series of small-pore silica-alumina molecular sieves of the ABC-6 family via a crystallization method. A series of ABC-6 family small-pore silica-alumina molecular sieves with ERI, SWY, LEV, AFX, and PTT type framework structures are hydrothermally synthesized within an ultra-short crystallization time (6–10 h).
[0051] Optionally, the inorganic base MOH is selected from sodium hydroxide and / or potassium hydroxide.
[0052] Optionally, the template agent R is selected from 1,4-bis(N-trimethyl)butane ammonium hydroxide, 1,5-bis(N-trimethyl)pentane ammonium hydroxide, 1,4-bis(N-triethyl)butane ammonium hydroxide, 1,5-bis(N-triethyl)pentane ammonium hydroxide, 1,6-bis(N-triethyl)hexane ammonium hydroxide, 1,8-bis(N-triethyl)octane ammonium hydroxide, 1,6-bis(N-trimethyl)hexane ammonium hydroxide, 1,6-(1,4-diazabicyclo[2]] hydroxide. At least one of the following: [2.2]octane]hexylammonium salt, 1,8-hydroxy(1,4-diazabicyclo[2.2.2]octane)octylammonium salt, 1,10-hydroxy(1,4-diazabicyclo[2.2.2]octane)decylammonium salt, mepiquat chloride, 1,4-hydroxy(1,4-diazabicyclo[2.2.2]octane)butylammonium salt, 5-hydroxyazospiro[4.4]ammonium salt, and 1,12-hydroxy(1,4-diazabicyclo[2.2.2]octane)dodecylammonium salt.
[0053] Optionally, the crystallization conditions include:
[0054] Crystallization temperature: 100~200℃;
[0055] Crystallization time: 1 to 72 hours.
[0056] Optionally, the crystallization conditions include:
[0057] Crystallization temperature: 135~160℃;
[0058] Crystallization time: 2 to 12 hours.
[0059] Optionally, the crystallization conditions include:
[0060] Crystallization temperature: 145~155℃;
[0061] Crystallization time: 4 to 10 hours.
[0062] Optionally, the crystallization temperature is selected from any value or a range between 100℃, 110℃, 120℃, 130℃, 135℃, 140℃, 145℃, 150℃, 155℃, 160℃, 170℃, 175℃, 180℃, 190℃, and 200℃.
[0063] Optionally, the crystallization time is selected from any value or a range between 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, 24 hours, 30 hours, 36 hours, 42 hours, 48 hours, 54 hours, 60 hours, 66 hours, and 72 hours.
[0064] Optionally, the crystallization is carried out under rotational or static conditions.
[0065] In this application, the term "static crystallization" refers to the crystallization process in which the vessel containing the initial gel mixture is placed statically in an oven without stirring the mixture in the synthesis vessel.
[0066] In this application, the term "rotational crystallization" refers to the process in which the synthesis vessel containing the initial gel mixture is in a non-static state during crystallization, such as being flipped or rotated; or the process in which the mixture inside the synthesis vessel is stirred during crystallization.
[0067] Optionally, after crystallization, the process may also include separation, washing, and drying steps.
[0068] The beneficial effects that this application can produce include:
[0069] This application provides a rapid method for preparing ABC-6 family series of small-pore aluminosilicate molecular sieves. The method utilizes SOD aluminosilicate molecular sieves from this family as both silicon and aluminum sources to synthesize various small-pore aluminosilicate molecular sieves with different topological structures from the ABC-6 family. These include, but are not limited to, small-pore aluminosilicate molecular sieves with ERI, SWY, LEV, AFX, and PTT framework structures. This preparation method is simple and effectively accelerates the formation of small-pore aluminosilicate molecular sieves from the ABC-6 family, shortening the crystallization time to 4–10 hours. Attached Figure Description
[0070] Figure 1 These are the X-ray powder diffraction (XRD) and scanning electron microscope (SEM) images of the SOD-type silica-alumina molecular sieve obtained in Example 1 of this invention, where a is the XRD image and b is the SEM image, with a scale of 10 μm.
[0071] Figure 2These are the X-ray powder diffraction (XRD) and scanning electron microscope (SEM) images of product samples 1 and 2 obtained in Examples 2-3 of this invention, wherein a is the XRD pattern of sample 1 and 2, b is the SEM image of sample 1 at a scale of 500 nm, and c is the SEM image of sample 2 at a scale of 500 nm.
[0072] Figure 3 These are the X-ray powder diffraction (XRD) and scanning electron microscope (SEM) images of product samples 3, 4, and 5 obtained in Examples 4-6 of this invention. Among them, a is the XRD pattern of sample 1, 2, and 3, b is the SEM image of sample 1 with a scale of 2 μm, c is the SEM image of sample 2 with a scale of 3 μm, and d is the SEM image of sample 3 with a scale of 3 μm.
[0073] Figure 4 These are the X-ray powder diffraction (XRD) and scanning electron microscope (SEM) images of product sample 6 obtained in Example 7 of this invention, where a is the XRD image and b is the SEM image, with a scale of 500 nm.
[0074] Figure 5 These are the X-ray powder diffraction (XRD) and scanning electron microscope (SEM) images of the product sample 7 obtained in Example 8 of this invention, where a is the XRD image and b is the SEM image, with a scale of 500 nm.
[0075] Figure 6 These are the X-ray powder diffraction (XRD) and scanning electron microscope (SEM) images of product sample 8 obtained in Example 9 of this invention, where a is the XRD image and b is the SEM image, with a scale of 500 nm. Detailed Implementation
[0076] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0077] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.
[0078] The analysis method in the embodiments of this application is as follows:
[0079] The phase analysis of the samples was performed by X-ray powder diffraction (XRD) using an X'Pert PRO X-ray diffractometer from PANalytical, Netherlands, with a Cu target, Kα light source, 40 kV voltage, and 40 mA current.
[0080] The composition of the samples was analyzed by X-ray fluorescence spectroscopy (XRF) on a Philips Magix-601 X-ray fluorescence spectrometer.
[0081] Sample morphology analysis was performed using a scanning electron microscope (SEM) with a TM3000.
[0082] The samples were thermally analyzed using a TAQ-600 thermal analyzer at a heating rate of 10℃ / min from room temperature to 900℃.
[0083] Example 1: Preparation of SOD (Si / Al = 10.86) type silica-alumina molecular sieve
[0084] 3.14 g of silica gel for chromatography, 1.00 g of sodium silicate nonahydrate, and 0.466 g of sodium aluminate were mixed and ground until homogeneous. Then, 5.2 g of ethylene glycol was added to the mixture, and grinding was continued for 5 minutes to form a homogeneous gel-like solid. The mixture was then transferred to a stainless steel autoclave and crystallized at 200 °C for 24 hours. After crystallization, the solid product was obtained by centrifugation, washed three times with distilled water, and dried overnight in air at 100 °C. XRF elemental analysis determined that the final product had a silica-to-alumina ratio of 10.86, denoted as C-1.
[0085] Figure 1 Curve C-1 is the X-ray powder diffraction (XRD) pattern of the synthesized SOD-type molecular sieve. By comparing it with the standard diffraction pattern of the International Molecular Sieve Association, it is shown that it is a pure-phase molecular sieve with an SOD framework structure. The particle size of the synthesized SOD-type molecular sieve was observed to be 5-7 μm by scanning electron microscopy.
[0086] Examples 2-6: Preparation of Samples 1-5
[0087] Sample 1: 0.5102 g of SOD-type molecular sieve with a silica-to-alumina ratio of 10.86 prepared in Example 1, 0.7869 g of 1,4-bis(N-trimethyl)butane diammonium hydroxide (25 wt%), and 0.0943 g of KOH (99 wt%) were added to 2.4081 g of deionized water. The mixture was stirred at room temperature for 2 h, and after thorough mixing, it was transferred to a stainless steel autoclave and crystallized at 150 °C for 4 h. The specific proportions are shown in Table 1. The product was obtained by centrifugation, washed with deionized water, and dried in air at 100 °C overnight. Sample 1 with an ERI framework structure was obtained, denoted as C-2.
[0088] Samples 2-5 were synthesized using the same process as Sample 1, except that the template agent 1,4-bis(N-trimethyl)butane ammonium salt of hydroxide was replaced by 1,6-bis(N-trimethyl)hexane ammonium salt of hydroxide, 1,6-(1,4-diazabicyclo[2.2.2]octane)hexyl ammonium salt of hydroxide, 1,8-(1,4-diazabicyclo[2.2.2]octane)octyl ammonium salt of hydroxide, and 1,10-(1,4-diazabicyclo[2.2.2]octane)decyl ammonium salt of hydroxide, respectively. The crystallization time was extended to 6 h, 6 h, 6 h, and 10 h, respectively, to obtain Sample 2 with an ERI framework structure and Samples 3, 4, and 5 with an SWY framework structure, denoted as C-3, C-4, C-5, and C-6, respectively. The specific proportions are shown in Table 1.
[0089] Figure 2 Curves C-2 and C-3 are the X-ray powder diffraction patterns of sample 1 and sample 2, respectively. By comparing them with the standard diffraction patterns of the International Molecular Sieve Association, it can be seen that both sample 1 and sample 2 are silica-alumina molecular sieves with an ERI-type structure. Scanning electron microscopy revealed that the particle sizes of sample 1 and sample 2 are 300 nm and 500 nm, respectively.
[0090] Figure 3 Curves C-4, C-5, and C-6 are the X-ray powder diffraction patterns of samples 3, 4, and 5, respectively. Comparison with the standard diffraction patterns from the International Molecular Sieve Association confirms that samples 3, 4, and 5 are all silica-alumina molecular sieves with an SWY-type structure. Scanning electron microscopy revealed particle sizes of 600 nm, 1.5 μm, and 2 μm for samples 3, 4, and 5, respectively.
[0091] Examples 7-9: Preparation of Samples 6-8
[0092] Sample 6: 0.5102 g of SOD-type molecular sieve with a silica-to-alumina ratio of 10, 0.7869 g of mepiquat chloride (99 wt%), and 0.1019 g of NaOH (98 wt%) were added to 2.9983 g of deionized water. The mixture was stirred at room temperature for 2 hours until homogeneous, then transferred to a stainless steel autoclave and crystallized at 150 °C for 6 hours. The specific proportions are shown in Table 1. The product was obtained by centrifugation, washed with deionized water, and dried overnight in air at 100 °C. Sample 6, denoted as C-7, was obtained with a LEV framework structure.
[0093] Samples 7 and 8 (denoted as C-8 and C-9) were synthesized using the same process as sample 6, except that the template agent mepiquat chloride was replaced by 1,4-hydroxy(1,4-diazabicyclo[2.2.2]octane)butylammonium salt and 5-hydroxyazospirol[4.4]ammonium salt, respectively. The crystallization times were 6 h and 10 h, respectively, to obtain sample 7 with an AFX framework structure and sample 8 with a PTT framework structure. The specific proportions are shown in Table 1. Figure 4 The middle curve C-7 is the X-ray powder diffraction pattern of sample 6. By comparing it with the standard diffraction pattern of the International Molecular Sieve Association, it can be seen that sample 6 is a silica-alumina molecular sieve with a LEV-type structure. Scanning electron microscopy shows that the particle size of the synthesized sample 6 is about 500 nm.
[0094] Figure 5 The middle curve C-8 is the X-ray powder diffraction pattern of sample 7. By comparing it with the standard diffraction pattern of the International Molecular Sieve Association, it can be seen that sample 7 is a silica-alumina molecular sieve with an AFX-type structure. Scanning electron microscopy shows that the particle size of sample 7 is about 300 nm.
[0095] Figure 6 The middle curve C-9 is the X-ray powder diffraction pattern of sample 8. By comparing it with the standard diffraction pattern of the International Molecular Sieve Association, it can be determined that sample 8 is a silica-alumina molecular sieve with a PTT-type structure. Scanning electron microscopy revealed that the particle size of sample 8 is approximately 300 nm.
[0096] Table 1. Raw material types, proportions, and crystallization conditions for samples 1-8 in Examples 2-9.
[0097]
[0098]
[0099] Table 2 shows the structures of the template agents used in the specific synthesis steps of Examples 2-9.
[0100]
[0101] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A method for preparing ABC-6 family series small-pore silica-alumina molecular sieves, characterized in that, Includes the following steps: (S1) Add the silica-alumina molecular sieve with SOD-type framework structure to a mixture containing water, template agent R, and inorganic base MOH and mix evenly to obtain an initial gel mixture; The molar ratios of the raw materials in the initial gel mixture are as follows: Al2O3 / SiO2 = 0.01~0.10; MOH / SiO2 = 0.1~1.0; H2O / SiO2 = 5~50; R / SiO2 = 0.01~1.0; Wherein, SiO2 is measured by the number of moles of SiO2 contained in the silica-alumina molecular sieve with an SOD-type framework structure; Al2O3 is expressed in moles as the number of Al2O3 contained in a silica-alumina molecular sieve with an SOD-type framework structure. The inorganic base MOH is expressed in terms of its own molar number; the inorganic base MOH is selected from sodium hydroxide and / or potassium hydroxide; H2O is measured by its own number of moles; The template agent R is defined by its own molar quantity; the template agent R is selected from 1,4-bis(N-trimethyl)butane ammonium salt of hydroxide, 1,5-bis(N-trimethyl)pentane ammonium salt of hydroxide, 1,4-bis(N-triethyl)butane ammonium salt of hydroxide, 1,5-bis(N-triethyl)pentane ammonium salt of hydroxide, 1,6-bis(N-triethyl)hexane ammonium salt of hydroxide, 1,8-bis(N-triethyl)octane ammonium salt of hydroxide, 1,6-bis(N-triethyl)hexane ammonium salt of hydroxide, and 1,8-bis(N-triethyl)octane ammonium salt of hydroxide. At least one of the following: (methyl)hexane ammonium salt, (1,6-hydroxy(1,4-diazabicyclo[2.2.2]octane)hexyl ammonium salt, (1,8-hydroxy(1,4-diazabicyclo[2.2.2]octane)octyl ammonium salt, (1,10-hydroxy(1,4-diazabicyclo[2.2.2]octane)decyl ammonium salt, mepiquat chloride, (1,4-hydroxy(1,4-diazabicyclo[2.2.2]octane)butyl ammonium salt, (5-hydroxyazospirol[4.4]ammonium salt), and (1,12-hydroxy(1,4-diazabicyclo[2.2.2]octane)dodecyl ammonium salt; (S2) The initial gel mixture obtained in step (S1) is placed in a sealed container and crystallized to obtain the ABC-6 family series of small-pore silica-alumina molecular sieves. The molecular sieve includes one of the following framework structures: ERI, SWY, LEV, AFX, and PTT.
2. The preparation method according to claim 1, characterized in that, The silicon-aluminum molecular sieve with an SOD-type framework structure has a silicon-aluminum ratio of 5 to 100.
3. The preparation method according to claim 1, characterized in that, The particle size of the silicon-aluminum molecular sieve with the SOD-type framework structure is 4~10μm.
4. The preparation method according to claim 1, characterized in that, The conditions for crystallization include: Crystallization temperature: 100~200℃; Crystallization time: 1~72 hours.
5. The preparation method according to claim 1, characterized in that, The conditions for crystallization include: Crystallization temperature: 135~160℃; Crystallization time: 2~12 hours.
6. The preparation method according to claim 1, characterized in that, The crystallization is carried out under rotational or static conditions; After crystallization, the process also includes separation, washing, and drying steps.