Method for synthesizing SSZ-13 molecular sieves with different morphologies based on alkali metal ion assistance

Abstract

The invention relates to the field of SSZ-13 molecular sieves, in particular to a method for synthesizing SSZ-13 molecular sieves with different morphologies based on alkali metal ion assistance, and the synthesis method comprises the following steps: mixing a silicon source, an aluminum source, alkali and a template agent, stirring, and carrying out hydrothermal crystallization to prepare the SSZ-13 molecular sieves; the SSZ-13 molecular sieve is subjected to suction filtration, washing, drying and roasting to obtain the Na (K or Li or Cs)-SSZ-13 molecular sieve, alkali metal ions of the alkali comprise K < + >, Na < + >, Li < + > and Cs < + >, and the alkali metal ions can accelerate the crystallization process; the method can be used for preparing the Si / Al SSZ-13 molecular sieve with adjustable morphology; the Si / Al distribution of the SSZ-13 molecular sieve is 3-15, and the morphology transits from an ellipsoid to a cube. According to the invention, the SSZ-13 molecular sieve with Si / Al, controllable morphology and ultrafast crystallization can be prepared by simply adjusting the ratio, and the synthesized SSZ-13 molecular sieve with cubic morphology has excellent NH3-SCR performance after ion exchange.

Description

Technical Field

[0001] The present invention relates to the field of SSZ-13 molecular sieves, and particularly to a method for synthesizing SSZ-13 molecular sieves with different morphologies assisted by alkali metal ions. Background Art

[0002] The SSZ-13 molecular sieve has a CHA topological configuration, and its framework is composed of silicon-oxygen tetrahedrons and aluminum-oxygen tetrahedrons connected to each other by covalent bonds, with a three-dimensional through-pore structure of 0.38×0.38×0.38 nm. Researchers have found that Cu-exchanged SSZ-13 molecular sieves have very high activity for the selective catalytic reduction of NO with NH3 (NH3-SCR) in a relatively wide temperature range ([1] JaHun Kwak et al. Excellent activity and selectivity of Cu-SSZ-13 in the selective catalytic reduction of NOx with NH3. J. Catal. 2010, 275, 187-190.). Therefore, Cu-exchanged SSZ-13 molecular sieves play an important role in commercial catalysts for the NH3-SCR reaction.

[0003] The different morphologies of zeolites can affect the micropore morphology and surface acidity, influencing the diffusion of reactants in the pores. In addition, the different morphologies of zeolites can also affect the local environment and state of the active components, thus exhibiting different catalytic activities and selectivities ([2] Céline Pagis et al. Hollow Zeolite Structures: An Overview of Synthesis Methods. Chem. Mater. 2016, 28, 15, 5205–5223. [3] Hao Wang et al. Highly Efficient NO Abatement over Cu-ZSM-5 with Special Nanosheet Features. Environ. Sci. Technol. 2021, 55, 8, 5422–5434.); currently, the main method for regulating the morphology of SSZ-13 is to synthesize SSZ-13 with different morphologies by adding an additional organic template ([4] Huifang Zhang et al. Seed-assisted synthesis of a nanosheet-assembled hierarchical SSZ-13 zeolite by coupling a small amount of TMAdaOH with TPOAC. New. J. Chem., 2024, 48, 8352-8360. [5] Li Chao, Zhao Changyan, Zha Lelin, Tian Wei. A kind of SSZ-13 zeolite, a method for regulating its crystal morphology and applications. CN 114538467 A. [6] Ya Guo et al. Cost-effective synthesis of CHA zeolites with controllable morphology and size. Chem. Eng. J. 2019, 358, 331-339.). However, the addition of an additional organic template will increase the cost and cause environmental pollution during the calcination process.

[0004] To solve the above problems, the present invention uses alkali metal ions to assist in the synthesis of SSZ-13 zeolites with different morphologies, uses trimethyladamantyl ammonium hydroxide as a template, and by regulating Si / Al, M / Na + (M is Li + or K + or Cs +) and other gel ratio parameters to achieve the controllable rapid synthesis of the morphology of SSZ-13 zeolite with Si / Al of 3-15. The synthesized cubic SSZ-13 zeolite has excellent NH3-SCR performance after ion exchange. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the present invention provides a method for synthesizing SSZ-13 zeolite. The synthesis method is as follows: deionized water, a silicon source, an aluminum source, an alkali, and a template agent are stirred and aged to form a gel, and then hydrothermally crystallized to obtain SSZ-13 zeolite. The alkali metal ions of the alkali include K + , Na + , Li + , Cs + or one or more of them; by regulating the Si / Al and M / Na + ratio parameters of the gel, the controllable synthesis of the morphology of SSZ-13 zeolite is achieved.

[0006] Preferably, the chemical composition of the gel ratio satisfies the following molar ranges: SiO2 / Al2O3 = 6-30; OH - / SiO2 = 0.001-0.8; H2O / SiO2 = 6-70; R / SiO2 = 0.03-0.6, where R is an organic template agent;

[0007] M / Na + = 0-∞.

[0008] Preferably, in the hydrothermal crystallization process, the temperature is 120-200 °C.

[0009] Preferably, in the hydrothermal crystallization process, the time is 0.5-168 hours.

[0010] Preferably, the product after crystallization is filtered, washed clean, and then dried overnight.

[0011] Preferably, the product after crystallization is filtered, dried, and then calcined at 600 °C for 6 hours

[0012] Preferably, the silicon source is silica sol; the aluminum source is sodium aluminate or aluminum hydroxide or aluminum sulfate octadecahydrate; the alkali is lithium hydroxide or sodium hydroxide or potassium hydroxide or cesium hydroxide; the template agent is trimethyladamantyl ammonium hydroxide.

[0013] Using the above SSZ-13 zeolite after ion exchange to catalyze the NH3-SCR reaction: the raw materials are ammonia, nitric oxide, oxygen, water vapor, and nitrogen. The ammonia concentration is 500-600 ppm, the nitric oxide concentration is 500 ppm, the oxygen concentration is 3%-10%, and the water vapor concentration is 5%-10%. The rest is nitrogen, and the GHSV is 200,000-800,000 -1Under the above conditions, the catalyst undergoes a reaction.

[0014] The present invention has the following advantages:

[0015] 1) In the preparation process of the SSZ-13 molecular sieve in the present invention, no second organic template agent is additionally added, which can reduce costs and is more environmentally friendly;

[0016] 2) In the present invention, alkali metal ions can accelerate the crystallization process of the SSZ-13 molecular sieve and improve the preparation efficiency;

[0017] 3) The prepared SSZ-13 molecular sieve has no impurity phase, the Si / Al can be controllably adjusted within 3 - 15, the morphology can be controllably adjusted, and the crystal grain size is uniform;

[0018] 4) The prepared SSZ-13 molecular sieve has excellent activity in the NH3-SCR reaction after ion exchange.

[0019] 5) The said alkali metal ions can accelerate the crystallization process; the method can prepare an SSZ-13 molecular sieve with adjustable Si / Al and morphology; the Si / Al distribution of the said SSZ-13 molecular sieve is 3 - 15, and the morphology transitions from ellipsoidal to cubic. The present invention can prepare an SSZ-13 molecular sieve with controllable Si / Al and morphology and ultrafast crystallization by simply adjusting the gel ratio. The synthesized cubic-shaped SSZ-13 molecular sieve has excellent NH3-SCR performance after ion exchange. Description of the Drawings

[0020] Figure 1 is a schematic diagram of the crystallization curve of the molecular sieve in Examples 1 - 14 of the present invention.

[0021] Figure 2 is the XRD pattern of the catalyst in Examples 1 - 8 of the present invention.

[0022] Figure 3 is the XRD pattern of the catalyst in Examples 9 - 14 of the present invention.

[0023] Figure 4 is the scanning electron microscope schematic diagram of the molecular sieve in Examples 8, 14 - 17 of the present invention.

[0024] Figure 5 is the schematic diagram of the NH3-SCR performance of the catalyst in Examples 8, 14 of the present invention. Detailed Embodiments

[0025] To make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the technical solutions in the detailed embodiments of the present invention are clearly and completely described below to further elaborate the present invention. Obviously, the described detailed embodiments are only a part of the embodiments of the present invention, rather than all of them.

[0026] The present invention utilizes alkali metal ions to assist in the synthesis of SSZ-13 zeolites with different morphologies. Using trimethyladamantyl ammonium hydroxide as a template agent, by regulating Si / Al, M / Na + (where M is Li + or K + or Cs + ), etc., gel ratio parameters are used to achieve the controllable and rapid synthesis of SSZ-13 zeolites with Si / Al of 3-15. The synthesized SSZ-13 zeolites have excellent NH3-SCR performance after ion exchange.

[0027] The present invention is achieved through the following technical solutions:

[0028] The alkali metal ions of the alkali include Na + or Li + or K + or Cs + , Mix the silicon source, aluminum source, alkali and template agent, stir, age, and hydrothermally crystallize to obtain Na(K or Li or Cs)-SSZ-13 zeolite. By regulating Si / Al, M / Na + (where M is Li + or K + or Cs + ), etc., gel ratio parameters are used to achieve the controllable and rapid synthesis of SSZ-13 zeolites with Si / Al of 3-15.

[0029] A method for synthesizing SSZ-13 zeolite, comprising the following steps:

[0030] Sequentially add the silicon source, aluminum source, alkali and template agent into the inner lining of the reaction kettle, stir and age for 2-13 hours to obtain a gel. The chemical composition of the gel ratio satisfies the following molar ranges: SiO2 / Al2O3 = 6-30; OH - / SiO2 = 0.01-0.8; H2O / SiO2 = 6-70; R / SiO2 = 0.08-0.6, where R is an organic template agent; M / Na + = 0-∞, where M is Li + or K + or Cs + . Add 1% of the seed crystals to the gel, stir for 10-80 min, then transfer it to a hydrothermal kettle and hydrothermally crystallize at 120-200 °C for 0.5-168 hours; after the reaction is completed, wait for it to cool, filter, wash, dry, and calcine to obtain Na(K or Li or Cs)-SSZ-13 zeolite.

[0031] Catalytic NH3-SCR reaction after ion exchange of the above SSZ-13 molecular sieve: The raw materials are ammonia, nitric oxide, oxygen, water vapor and nitrogen. The ammonia concentration is 500-600 ppm, the nitric oxide concentration is 500 ppm, the oxygen concentration is 3%-10%, and the water vapor concentration is 5%-10%. The rest is nitrogen, and the GHSV is 200,000-800,000. -1 The catalyst reacts under the above conditions.

[0032] Example 1

[0033] The preparation of SSZ-13 molecular sieve with Si / Al 7 Na:K = 4:0 crystallized for 6 h is as follows:

[0034] The silicon source, aluminum source, base and template agent are sequentially added to the inner lining of the reaction kettle and stirred and aged for 2-13 hours. The chemical composition of the gel ratio satisfies the following molar range: SiO2 / Al2O3 = 14; OH - / SiO2 = 0.56; H2O / SiO2 = 26; R / SiO2 = 0.088, where R is an organic template agent. The silicon source is silica sol, the aluminum source is aluminum sulfate octadecahydrate, the base is sodium hydroxide, and the template agent is trimethyladamantyl ammonium hydroxide. 1% seed crystal is added to the gel and stirred for 5 h, then transferred to a hydrothermal kettle and hydrothermally crystallized at 170 °C for 6 h; after the reaction is completed and cooled, it is filtered, washed, dried overnight at 100 °C, and calcined at 600 °C for 6 hours to obtain Na / SSZ-13 molecular sieve.

[0035] Example 2

[0036] The preparation of SSZ-13 molecular sieve with Si / Al 7 Na:K = 4:0 crystallized for 12 h is as follows:

[0037] The silicon source, aluminum source, base and template agent are sequentially added to the inner lining of the reaction kettle and stirred and aged for 2-13 hours. The chemical composition of the gel ratio satisfies the following molar range: SiO2 / Al2O3 = 14; OH - / SiO2 = 0.56; H2O / SiO2 = 26; R / SiO2 = 0.088, where R is an organic template agent. The silicon source is silica sol, the aluminum source is aluminum sulfate octadecahydrate, the base is sodium hydroxide, and the template agent is trimethyladamantyl ammonium hydroxide. 1% seed crystal is added to the gel and stirred for 5 h, then transferred to a hydrothermal kettle and hydrothermally crystallized at 170 °C for 12 h; after the reaction is completed and cooled, it is filtered, washed, dried overnight at 100 °C, and calcined at 600 °C for 6 hours to obtain Na / SSZ-13 molecular sieve.

[0038] Example 3

[0039] The preparation of SSZ-13 molecular sieve with Si / Al 7 Na:K = 4:0 crystallized for 18 h is as follows:

[0040] Add the silicon source, aluminum source, alkali, and template agent into the inner lining of the reaction kettle in sequence and stir and age for 2 - 13 hours. The chemical composition of the gel formulation satisfies the following molar ranges: SiO2 / Al2O3 = 14; OH - / SiO2 = 0.56; H2O / SiO2 = 26; R / SiO2 = 0.088, where R is the organic template agent. The silicon source is silica sol, the aluminum source is aluminum sulfate octadecahydrate, the alkali is sodium hydroxide, and the template agent is trimethyladamantyl ammonium hydroxide. Add 1% seed crystals to the gel and stir for 5 h, then transfer it into a hydrothermal kettle and hydrothermally crystallize at 170 °C for 18 h; after the reaction ends and it cools down, filter, wash, dry overnight at 100 °C, and calcine at 600 °C for 6 hours to obtain Na / SSZ-13 molecular sieve.

[0041] Example 4

[0042] Preparation of SSZ-13 molecular sieve with Si / Al 7 Na:K = 4:0 crystallized for 24 h is as follows:

[0043] Add the silicon source, aluminum source, alkali, and template agent into the inner lining of the reaction kettle in sequence and stir and age for 2 - 13 hours. The chemical composition of the gel formulation satisfies the following molar ranges: SiO2 / Al2O3 = 14; OH - / SiO2 = 0.56; H2O / SiO2 = 26; R / SiO2 = 0.088, where R is the organic template agent. The silicon source is silica sol, the aluminum source is aluminum sulfate octadecahydrate, the alkali is sodium hydroxide, and the template agent is trimethyladamantyl ammonium hydroxide. Add 1% seed crystals to the gel and stir for 5 h, then transfer it into a hydrothermal kettle and hydrothermally crystallize at 170 °C for 24 h; after the reaction ends and it cools down, filter, wash, dry overnight at 100 °C, and calcine at 600 °C for 6 hours to obtain Na / SSZ-13 molecular sieve.

[0044] Example 5

[0045] Preparation of SSZ-13 molecular sieve with Si / Al 7 Na:K = 4:0 crystallized for 36 h is as follows:

[0046] Add the silicon source, aluminum source, alkali, and template agent into the inner lining of the reaction kettle in sequence and stir and age for 2 - 13 hours. The chemical composition of the gel formulation satisfies the following molar ranges: SiO2 / Al2O3 = 14; OH - / SiO2 = 0.56; H2O / SiO2 = 26; R / SiO2 = 0.088, where R is the organic template agent. The silicon source is silica sol, the aluminum source is aluminum sulfate octadecahydrate, the alkali is sodium hydroxide, and the template agent is trimethyladamantyl ammonium hydroxide. Add 1% seed crystals to the gel and stir for 5 h, then transfer it into a hydrothermal kettle and hydrothermally crystallize at 170 °C for 36 h; after the reaction ends and it cools down, filter, wash, dry overnight at 100 °C, and calcine at 600 °C for 6 hours to obtain Na / SSZ-13 molecular sieve.

[0047] Example 6

[0048] The preparation of SSZ-13 zeolite with Si / Al 7, Na:K = 4:0 and crystallization for 48 h is as follows:

[0049] The silicon source, aluminum source, alkali and template agent are successively added into the inner lining of the reaction kettle and stirred and aged for 2 - 13 hours. The chemical composition of the gel ratio satisfies the following molar range: SiO2 / Al2O3 = 14; OH - / SiO2 = 0.56; H2O / SiO2 = 26; R / SiO2 = 0.088, where R is the organic template agent. The silicon source is silica sol, the aluminum source is aluminum sulfate octadecahydrate, the alkali is sodium hydroxide, and the template agent is trimethyladamantyl ammonium hydroxide. 1% seed crystal is added to the gel and stirred for 5 h, then transferred to a hydrothermal kettle and hydrothermally crystallized at 170 °C for 48 h; after the reaction is completed and it is cooled, filtered, washed, dried overnight at 100 °C, and calcined at 600 °C for 6 hours to obtain Na / SSZ-13 zeolite.

[0050] Example 7

[0051] The preparation of SSZ-13 zeolite with Si / Al 7, Na:K = 4:0 and crystallization for 60 h is as follows:

[0052] The silicon source, aluminum source, alkali and template agent are successively added into the inner lining of the reaction kettle and stirred and aged for 2 - 13 hours. The chemical composition of the gel ratio satisfies the following molar range: SiO2 / Al2O3 = 14; OH - / SiO2 = 0.56; H2O / SiO2 = 26; R / SiO2 = 0.088, where R is the organic template agent. The silicon source is silica sol, the aluminum source is aluminum sulfate octadecahydrate, the alkali is sodium hydroxide, and the template agent is trimethyladamantyl ammonium hydroxide. 1% seed crystal is added to the gel and stirred for 5 h, then transferred to a hydrothermal kettle and hydrothermally crystallized at 170 °C for 60 h; after the reaction is completed and it is cooled, filtered, washed, dried overnight at 100 °C, and calcined at 600 °C for 6 hours to obtain Na / SSZ-13 zeolite.

[0053] Example 8

[0054] The preparation of SSZ-13 zeolite with Si / Al 7, Na:K = 4:0 and crystallization for 72 h is as follows:

[0055] The silicon source, aluminum source, alkali and template agent are successively added into the inner lining of the reaction kettle and stirred and aged for 2 - 13 hours. The chemical composition of the gel ratio satisfies the following molar range: SiO2 / Al2O3 = 14; OH -Si / Al = 0.56; H2O / SiO2 = 26; R / SiO2 = 0.088, where R is an organic templating agent. The silicon source is silica sol, the aluminum source is aluminum sulfate octadecahydrate, the base is sodium hydroxide, and the templating agent is trimethyladamantyl ammonium hydroxide. 1% seed crystals were added to the gel and stirred for 5 h, then transferred to a hydrothermal autoclave and hydrothermally crystallized at 170 °C for 72 h; after the reaction ended and it was cooled, it was filtered, washed, dried overnight at 100 °C, and calcined at 600 °C for 6 h to obtain Na / SSZ-13 molecular sieve.

[0056] Example 9

[0057] The preparation of SSZ-13 molecular sieve with Si / Al 7, Na:K = 2:2 and crystallization for 12 h is as follows:

[0058] The silicon source, aluminum source, base and templating agent were sequentially added to the inner lining of the reaction kettle and stirred and aged for 2 - 13 h. The chemical composition of the gel ratio satisfied the following molar range: SiO2 / Al2O3 = 14; OH - / SiO2 = 0.56; Na:K = 2:2; H2O / SiO2 = 26; R / SiO2 = 0.088, where R is an organic templating agent. The silicon source is silica sol, the aluminum source is aluminum sulfate octadecahydrate, the base is sodium hydroxide and potassium hydroxide, and the templating agent is trimethyladamantyl ammonium hydroxide. 1% seed crystals were added to the gel and stirred for 5 h, then transferred to a hydrothermal autoclave and hydrothermally crystallized at 170 °C for 12 h; after the reaction ended and it was cooled, it was filtered, washed, dried overnight at 100 °C, and calcined at 600 °C for 6 h to obtain Na / K / SSZ-13 molecular sieve.

[0059] Example 10

[0060] The preparation of SSZ-13 molecular sieve with Si / Al 7, Na:K = 2:2 and crystallization for 24 h is as follows:

[0061] The silicon source, aluminum source, base and templating agent were sequentially added to the inner lining of the reaction kettle and stirred and aged for 2 - 13 h. The chemical composition of the gel ratio satisfied the following molar range: SiO2 / Al2O3 = 14; OH - / SiO2 = 0.56; Na:K = 2:2; H2O / SiO2 = 26; R / SiO2 = 0.088, where R is an organic templating agent. The silicon source is silica sol, the aluminum source is aluminum sulfate octadecahydrate, the base is sodium hydroxide and potassium hydroxide, and the templating agent is trimethyladamantyl ammonium hydroxide. 1% seed crystals were added to the gel and stirred for 5 h, then transferred to a hydrothermal autoclave and hydrothermally crystallized at 170 °C for 24 h; after the reaction ended and it was cooled, it was filtered, washed, dried overnight at 100 °C, and calcined at 600 °C for 6 h to obtain Na / K / SSZ-13 molecular sieve.

[0062] Example 11

[0063] The preparation of SSZ-13 zeolite with Si / Al 7, Na:K = 2:2 and crystallization for 36 h is as follows:

[0064] The silicon source, aluminum source, alkali and template agent are successively added into the inner lining of the reaction kettle and stirred for aging for 2 - 13 hours. The chemical composition of the gel ratio meets the following molar ranges: SiO2 / Al2O3 = 14; OH - / SiO2 = 0.56; Na:K = 2:2; H2O / SiO2 = 26; R / SiO2 = 0.088, where R is the organic template agent. The silicon source is silica sol, the aluminum source is aluminum sulfate octadecahydrate, the alkali is sodium hydroxide and potassium hydroxide, and the template agent is trimethyladamantyl ammonium hydroxide. 1% seed crystal is added to the gel and stirred for 5 h, then transferred into a hydrothermal kettle and hydrothermally crystallized at 170 °C for 36 h; after the reaction is completed and it is cooled, filtered by suction, washed, dried overnight at 100 °C, and calcined at 600 °C for 6 hours to obtain Na / K / SSZ-13 zeolite.

[0065] Example 12

[0066] The preparation of SSZ-13 zeolite with Si / Al 7, Na:K = 2:2 and crystallization for 48 h is as follows:

[0067] The silicon source, aluminum source, alkali and template agent are successively added into the inner lining of the reaction kettle and stirred for aging for 2 - 13 hours. The chemical composition of the gel ratio meets the following molar ranges: SiO2 / Al2O3 = 14; OH - / SiO2 = 0.56; Na:K = 2:2; H2O / SiO2 = 26; R / SiO2 = 0.088, where R is the organic template agent. The silicon source is silica sol, the aluminum source is aluminum sulfate octadecahydrate, the alkali is sodium hydroxide and potassium hydroxide, and the template agent is trimethyladamantyl ammonium hydroxide. 1% seed crystal is added to the gel and stirred for 5 h, then transferred into a hydrothermal kettle and hydrothermally crystallized at 170 °C for 48 h; after the reaction is completed and it is cooled, filtered by suction, washed, dried overnight at 100 °C, and calcined at 600 °C for 6 hours to obtain Na / K / SSZ-13 zeolite.

[0068] Example 13

[0069] The preparation of SSZ-13 zeolite with Si / Al 7, Na:K = 2:2 and crystallization for 60 h is as follows:

[0070] The silicon source, aluminum source, alkali and template agent are successively added into the inner lining of the reaction kettle and stirred for aging for 2 - 13 hours. The chemical composition of the gel ratio meets the following molar ranges: SiO2 / Al2O3 = 14; OH -Si / Al = 0.56; Na:K = 2:2; H2O / SiO2 = 26; R / SiO2 = 0.088, where R is an organic template. The silicon source is silica sol, the aluminum source is aluminum sulfate octadecahydrate, the alkali is sodium hydroxide and potassium hydroxide, and the template is trimethyladamantyl ammonium hydroxide. 1% seed crystals were added to the gel and stirred for 5 h, then transferred to a hydrothermal autoclave and hydrothermally crystallized at 170 °C for 60 h; after the reaction ended and it cooled, it was filtered, washed, dried overnight at 100 °C, and calcined at 600 °C for 6 h to obtain Na / K / SSZ-13 molecular sieve.

[0071] Example 14

[0072] The preparation of SSZ-13 molecular sieve with Si / Al = 7, Na:K = 2:2 and crystallization for 72 h is as follows:

[0073] The silicon source, aluminum source, alkali and template were successively added to the inner lining of the reaction kettle and stirred and aged for 2 - 13 h. The chemical composition of the gel ratio satisfied the following molar range: SiO2 / Al2O3 = 14; OH - / SiO2 = 0.56; Na:K = 2:2; H2O / SiO2 = 26; R / SiO2 = 0.088, where R is an organic template. The silicon source is silica sol, the aluminum source is aluminum sulfate octadecahydrate, the alkali is sodium hydroxide and potassium hydroxide, and the template is trimethyladamantyl ammonium hydroxide. 1% seed crystals were added to the gel and stirred for 5 h, then transferred to a hydrothermal autoclave and hydrothermally crystallized at 170 °C for 72 h; after the reaction ended and it cooled, it was filtered, washed, dried overnight at 100 °C, and calcined at 600 °C for 6 h to obtain Na / K / SSZ-13 molecular sieve.

[0074] Example 15

[0075] The preparation of SSZ-13 molecular sieve with Si / Al = 7, Na:K = 3:1 and crystallization for 72 h is as follows:

[0076] The silicon source, aluminum source, alkali and template were successively added to the inner lining of the reaction kettle and stirred and aged for 2 - 13 h. The chemical composition of the gel ratio satisfied the following molar range: SiO2 / Al2O3 = 14; OH - / SiO2 = 0.56; Na:K = 3:1; H2O / SiO2 = 26; R / SiO2 = 0.088, where R is an organic template. The silicon source is silica sol, the aluminum source is aluminum sulfate octadecahydrate, the alkali is sodium hydroxide and potassium hydroxide, and the template is trimethyladamantyl ammonium hydroxide. 1% seed crystals were added to the gel and stirred for 5 h, then transferred to a hydrothermal autoclave and hydrothermally crystallized at 170 °C for 72 h; after the reaction ended and it cooled, it was filtered, washed, dried overnight at 100 °C, and calcined at 600 °C for 6 h to obtain Na / K / SSZ-13 molecular sieve.

[0077] Example 16

[0078] The preparation of SSZ-13 zeolite with Si / Al 7, Na:K = 1:3 and crystallized for 72 h is as follows:

[0079] The silicon source, aluminum source, alkali and template agent are successively added into the inner lining of the reaction kettle and stirred for aging for 2 - 13 hours. The chemical composition of the gel ratio satisfies the following molar ranges: SiO2 / Al2O3 = 14; OH - / SiO2 = 0.56; Na:K = 1:3; H2O / SiO2 = 26; R / SiO2 = 0.088, where R is the organic template agent. The silicon source is silica sol, the aluminum source is aluminum sulfate octadecahydrate, the alkali is sodium hydroxide and potassium hydroxide, and the template agent is trimethyladamantyl ammonium hydroxide. 1% seed crystal is added to the gel and stirred for 5 h, then transferred into a hydrothermal kettle and hydrothermally crystallized at 170 °C for 72 h; after the reaction is completed and it is cooled, filtered, washed, dried overnight at 100 °C, and calcined at 600 °C for 6 hours to obtain Na / K / SSZ-13 zeolite.

[0080] Example 17

[0081] The preparation of SSZ-13 zeolite with Si / Al 7, Na:K = 0:4 and crystallized for 72 h is as follows:

[0082] The silicon source, aluminum source, alkali and template agent are successively added into the inner lining of the reaction kettle and stirred for aging for 2 - 13 hours. The chemical composition of the gel ratio satisfies the following molar ranges: SiO2 / Al2O3 = 14; OH - / SiO2 = 0.56; Na:K = 0:4; H2O / SiO2 = 26; R / SiO2 = 0.088, where R is the organic template agent. The silicon source is silica sol, the aluminum source is aluminum sulfate octadecahydrate, the alkali is sodium hydroxide and potassium hydroxide, and the template agent is trimethyladamantyl ammonium hydroxide. 1% seed crystal is added to the gel and stirred for 5 h, then transferred into a hydrothermal kettle and hydrothermally crystallized at 170 °C for 72 h; after the reaction is completed and it is cooled, filtered, washed, dried overnight at 100 °C, and calcined at 600 °C for 6 hours to obtain K / SSZ-13 zeolite.

[0083] The evaluation of the catalyst performance is as follows:

[0084] The molecular sieves prepared in Examples 8 and 14 are respectively used. After a series of ion exchanges, the catalyst volume space velocity GHSV = 200,000 h -1 , the gas composition: NO = NH3 = 500 ppm, O2 = 5 vol.%, H2O = 5%, N2 for balance, and the total gas flow rate is 500 ml / min; the reaction is carried out on a continuous flow micro fixed bed, and the concentration changes of NO, NH3, NO2, and N2O in the tail gas are measured by infrared spectroscopy. The test results are shown in Figure 5 .

[0085] As can be seen from the above, the present invention has the following advantages:

[0086] 1) In the preparation process of the SSZ-13 molecular sieve in the present invention, no second organic template agent is additionally added, which can reduce costs and is more environmentally friendly;

[0087] 2) The alkali metal ions in the present invention can accelerate the crystallization process of the SSZ-13 molecular sieve and improve the preparation efficiency;

[0088] 3) The prepared SSZ-13 molecular sieve has no impurity phase, the Si / Al can be controllably adjusted within 3-15, the morphology can be controllably adjusted, and the crystal grain size is uniform;

[0089] 4) The prepared SSZ-13 molecular sieve has excellent activity in the NH3-SCR reaction after ion exchange.

[0090] 5) The alkali metal ions can accelerate the crystallization process; the method can prepare an SSZ-13 molecular sieve with adjustable Si / Al and morphology; the Si / Al distribution of the SSZ-13 molecular sieve is 3-15, and the morphology transitions from ellipsoidal to cubic. The present invention can prepare an SSZ-13 molecular sieve with controllable Si / Al and morphology and ultrafast crystallization by simply adjusting the gel ratio. The synthesized cubic SSZ-13 molecular sieve has excellent NH3-SCR performance after ion exchange.

[0091] The above describes the main technical features, basic principles and related advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary specific embodiments, and can be implemented in other specific forms without departing from the concept or basic features of the present invention. Therefore, from any point of view, the above specific embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

[0092] In addition, it should be understood that although this specification is described according to each embodiment, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for synthesizing SSZ-13 molecular sieve, characterized in that: The method comprises: mixing and stirring a silicon source, an aluminum source, a base and a template agent to obtain a SSZ-13 molecular sieve by hydrothermal crystallization, wherein the alkali metal ions of the base include K + ,Na + ,Li + ,Cs + One or more of; By adjusting Si / Al, M / Na + Ratio parameters to achieve morphology-controlled synthesis of Si / Al 3-15 SSZ-13 molecular sieve; The M is Li + or K + or Cs + .

2. The method for synthesizing SSZ-13 molecular sieve according to claim 1, characterized in that: Deionized water, silicon source, aluminum source, alkali and template agent are stirred and aged to form a gel, and then hydrothermally crystallized to obtain SSZ-13 molecular sieve; By adjusting the Si / Al, M / Na + The ratio parameters are adjusted to achieve the morphology-controlled synthesis of Si / Al 3-15 SSZ-13 molecular sieve.

3. The method for synthesizing SSZ-13 molecular sieve according to claim 2, characterized in that: The chemical composition of the gel ratio meets the following molar range: SiO2 / Al2O3=6-30; OH - / SiO2=0.001-0.8;H2O / SiO2=6-70;R / SiO2=0.03-0.6,R is an organic template;M / Na + =0-∞.

4. The method for synthesizing SSZ-13 molecular sieve according to claim 2, characterized in that: The temperature of the hydrothermal crystallization process is 120-200°C.

5. The method for synthesizing SSZ-13 molecular sieve according to claim 2, characterized in that: The hydrothermal crystallization process takes 0.5-168 hours.

6. The method for synthesizing SSZ-13 molecular sieve according to claim 2, characterized in that: After crystallization, the product was filtered and washed clean, and then dried overnight.

7. The method for synthesizing SSZ-13 molecular sieve according to claim 6, characterized in that: The crystallized product was filtered, dried and calcined at 600°C for 6 hours.

8. A method for synthesizing SSZ-13 molecular sieve according to any one of claims 1 to 7, characterized in that: The silicon source is silica sol; The aluminum source is sodium aluminate, aluminum hydroxide or aluminum sulfate 18-hydrate; The base is lithium hydroxide, sodium hydroxide, potassium hydroxide or cesium hydroxide; The template agent is trimethyladamantyl ammonium hydroxide.

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