Method for rapidly synthesizing acidity-adjustable ZEO-1 molecular sieve

Abstract

The invention discloses a method for rapidly synthesizing an acidity-adjustable ZEO-1 molecular sieve, and belongs to the field of molecular sieve synthesis. According to the method, a seed crystal and an additional cationic auxiliary agent are introduced into a ZEO-1 molecular sieve synthesis system, and under the synergistic effect of the seed crystal and the auxiliary agent, rapid crystallization synthesis and wide-range acidity adjustment of the ZEO-1 molecular sieve under the condition of extremely low template agent dosage can be realized. According to the present invention, the synthesis process is efficient, simple and convenient, the ZEO-1 molecular sieve can be rapidly synthesized under the alkaline condition (taking OH <-> as the mineralizer) or the neutral condition (taking F <-> as the mineralizer), the ZEO-1 molecular sieve obtained through the method has characteristics of good crystallinity and high thermal stability, and the silicon-aluminum or silicon-boron atomic ratio can be adjusted in the large range of 4-200.

Description

Technical Field

[0001] The present invention belongs to the field of molecular sieve synthesis, and relates to a method for rapidly synthesizing ZEO-1 molecular sieve with adjustable acidity, in particular to a method for rapidly synthesizing supermacroporous molecular sieve ZEO-1, and also relates to the acidity adjustment thereof. Background Art

[0002] Molecular sieve materials are a class of inorganic microporous solid materials composed of TO4 (T represents an atom with an oxidation state of +4 or +3 in general, such as Si, P, Al, B, Ge, Ga, etc.; the T atom means a tetrahedral atom, that is, a framework atom participating in the molecular sieve framework) tetrahedrons sharing vertices. Generally, the composition of the molecular sieve can be expressed by the following empirical chemical formula: x(M 1 / n AO2):yYO2:zR:qH2O, where M represents one or more organic or inorganic cations with +n valence; A represents one or more trivalent elements; Y represents one or more tetravalent elements, usually Si; R represents one or more organic molecule. For a molecular sieve with a specific structure obtained by a specific synthesis method, whether it is a freshly synthesized product or a sample after calcination treatment, its chemical composition usually has a specific variation range. In addition, a molecular sieve with a specific structure needs to be further distinguished by powder X-ray diffraction, because different molecular sieves have different pore structures due to different crystal structures, and completely different diffraction patterns will be obtained in the powder X-ray diffraction test. The most important characteristic of the molecular sieve is its variable pore chemical composition, adjustable pore diameter and pore shape. These excellent characteristics endow the molecular sieve material with wide applications in the fields of adsorption, separation, catalysis, microelectronics and medical diagnosis.

[0003] According to the ring number of the pores, molecular sieve materials can be divided into small-pore, medium-pore, large-pore and supermacroporous molecular sieves, corresponding to window ring numbers of less than 8-membered rings, less than 10-membered rings, less than 12-membered rings and greater than 12-membered rings respectively. The pore sizes of the molecular sieve materials successfully applied in industry are usually below 1 nm, which greatly limits the molecular size and shape of the reaction substrates in the adsorption, separation and catalysis processes, and becomes a bottleneck in the practical application of molecular sieve materials. Developing and obtaining stable supermacroporous molecular sieves with pore diameters ranging from 1 nm to 2 nm, or even mesoporous molecular sieves, has always been a great challenge faced by inorganic chemists. This type of material will open the door to new catalytic applications in the fields of petrochemistry, fine chemistry and life science.

[0004] In December 2021, Chen Feijian et al. reported the first three-dimensionally stable extra-large pore silicoaluminate zeolite molecular sieve ZEO-1 (Science, 2021, 374, 1605-1608; CN202011346698.4; CN202111262220.8). It has a high Si content (the Si / Al ratio can reach 14.5), a non-interrupted fully connected framework structure, and excellent thermal and hydrothermal stabilities. The structure of ZEO-1 is complex. Its pore channels are composed of three-dimensional (3D) extra-large sixteen-membered ring (16MR) pore channels and three-dimensional twelve-membered ring (12MR) pore channels. The two sets of pore channel systems are highly connected, and three types of supercages with four 16MR and / or 12MR windows are formed. Two of these supercages are larger than the supercages of FAU, EMT, PST-32, and PST-2. These structural features make ZEO-1 one of the stable zeolites with ultra-low framework density and ultra-high specific surface area. Moreover, the active acidic sites in the pore channels endow ZEO-1 with excellent heavy oil conversion rate and light fuel (gasoline, diesel, and liquefied petroleum gas LPG) selectivity in catalytic cracking (FCC) reactions. Its performance can be comparable to that of highly optimized ultrastable Y zeolite (USY, FAU structure), showing great potential for industrial applications.

[0005] However, in the previous synthesis process of ZEO-1, there are still several challenges to achieve the industrial scale-up and application of ZEO-1. First, in the methods reported in previous literature, the synthesis of ZEO-1 materials requires a long crystallization time. Generally, the optimal crystallization time is 15 - 30 days, which is extremely unfavorable economically for industrial scale-up. Second, the amount of template used is large, and the template cost accounts for the vast majority of the entire synthesis cost. Third, it is difficult to adjust the acid amount of ZEO-1 molecular sieve, and only a narrow range of acid amount adjustment can be achieved, limiting the application scope of the material. Fourth, in the previous synthesis methods, the synthesis of ZEO-1 under alkaline conditions has high requirements for the purity of the template. The generation of ZEO-1 directed by low-purity templates is extremely unstable. Although the fluoride ion system has a high tolerance for the purity of the template and can achieve the stable synthesis of ZEO-1, as is well known, due to the high toxicity and high environmental harm of fluorine species, the introduction of fluoride ions in molecular sieve synthesis is not practical for its industrial scale-up synthesis.

[0006] In summary, developing a new method for the rapid crystallization, low template dosage, wide-range adjustable acid amount, and fluoride-free system synthesis of ZEO-1 molecular sieve is crucial for the industrial scale-up application of this material. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a method for rapidly synthesizing ZEO-1 zeolite with adjustable acidity, especially a new method for low-cost, fluoride-free rapid crystallization and acid amount regulation of super-large pore silicate zeolite ZEO-1. By introducing seed crystals and additional cationic additives, this method can achieve rapid crystallization and stable synthesis of ZEO-1 zeolite with low template dosage and wide-range regulation of acidity (silicon-aluminum or silicon-boron ratio) under alkaline conditions (fluoride-free system) or fluoride-containing conditions, which has very important practical application value.

[0008] To achieve the above purpose, the present invention adopts the following technical solutions:

[0009] The present invention provides a method for rapidly synthesizing ZEO-1 zeolite with adjustable acidity, especially a method for low-cost, fluoride-free rapid crystallization and wide-range acidity regulation of ZEO-1 zeolite, comprising the following steps:

[0010] (1) Under stirring, a boron group element compound, a silicon source, an organic template agent, water, a mineralizing agent, seed crystals and an additional cationic additive are mixed evenly in proportion to obtain a reaction gel.

[0011] The chemical composition of the reaction gel is (r1R1 + r2R2)(OH + X) r1+r2 :aHF:xA2O3:SiO2:wH2O, where R1 represents the positive charge group of the organic template agent, R2 represents the positive charge group of the additional cationic additive, X represents a halogen ion, and A is Al or B; the value ranges of the corresponding r1, r2, a, x, and w are: r1 = 0.1 - 2.0, r2 = 0.01 - 1.0, a = 0 - 2.0, x = 0 - 0.5, w = 1 - 30.

[0012] The silicon source is selected from at least one of silicic acid, silica gel, silica sol, tetraalkyl silicate, and water glass;

[0013] The boron group element compound is selected from at least one of sodium metaaluminate, aluminum isopropoxide, aluminum sulfate hexadecahydrate, aluminum hydroxide, and boric acid;

[0014] The additional cationic additive is a small-volume cation, which can be a metal ion or an organic cation, and is selected from at least one of sodium ion, potassium ion, calcium ion, magnesium ion, tetramethylammonium ion, tetraethylammonium ion, etc., and the additive is introduced directly as a halide salt or a basic form;

[0015] The organic template agent is a methyltricyclohexylphosphonium or ethyltricyclohexylphosphonium cation, and the template agent is introduced directly as a halide salt or a basic form;

[0016] The mineralizing agent can be OH - or F - ,OH -F from a basic organic templating agent or a basic additional cationic promoter - F from additionally added HF or NH4F - ;

[0017] The mixture further contains 0.01 ppm by weight to 10,000 ppm by weight of ZEO-1 molecular sieve seeds. The seeds can be ZEO-1 after removing the templating agent or directly synthesized ZEO-1 without removing the templating agent.

[0018] (2) Place the reaction gel under an infrared lamp or in an oven. After removing the excess solvent, transfer it to a stainless-steel autoclave, seal it, and perform high-temperature crystallization. After the crystallization is completed, wash the solid product to neutrality and dry it to obtain the ZEO-1 molecular sieve.

[0019] The crystallization temperature is 120 to 260 °C, and the crystallization time is 2 hours to 15 days;

[0020] The acidity of the ZEO-1 molecular sieve synthesized by this method can be adjusted, and the silicon-aluminum or silicon-boron atomic ratio can be adjusted within 4 - 200.

[0021] Compared with the existing synthesis methods, the present invention has the following advantages:

[0022] (1) It can greatly reduce the use of expensive and toxic organic templating agents, reducing the production cost of the molecular sieve;

[0023] (2) By introducing seeds and additional promoter cations, under the synergistic effect of the seeds and the promoter, the crystallization time of the ZEO-1 molecular sieve is greatly shortened, and highly crystalline ZEO-1 molecular sieve can be obtained in as fast as one day, reducing energy consumption;

[0024] (3) It can achieve the efficient and stable synthesis of ZEO-1 in a fluoride-free system, avoiding the introduction of highly toxic and highly environmentally polluting fluorine species, and is a green and efficient synthesis process route;

[0025] (4) Due to the introduction of additional cationic promoters, the acidity of the ZEO-1 molecular sieve can be adjusted within a large range, and the silicon-aluminum or silicon-boron atomic ratio can be adjusted within the range of 4 - 200. Description of the Drawings

[0026] Figure 1 Powder X-ray diffraction patterns of ZEO-1 molecular sieves synthesized with different promoters in Examples 1 - 3 (the light source is Cu target Kα ray).

[0027] Figure 2 Scanning electron micrograph (SEM) of the ZEO-1 molecular sieve synthesized in Example 1.

[0028] Figure 3Scanning electron microscopy (SEM) image of the ZEO-1 molecular sieve synthesized in Example 2.

[0029] Figure 4 Scanning electron microscopy (SEM) image of the ZEO-1 molecular sieve synthesized in Example 3. Detailed implementation manners

[0030] The implementation process and beneficial effects of the present invention are described in detail below through specific examples, aiming to help better understand the essence and characteristics of the present invention, and shall not be construed as a limitation on the scope of implementation of this case.

[0031] In the synthesis method for rapid crystallization of ZEO-1 of the present invention, the organic template agent is methyltricyclohexylphosphine or ethyltricyclohexylphosphonium cation, which can be used alone or in combination during the synthesis process.

[0032] The fluorine-free rapid crystallization synthesis method of the ZEO-1 ultra-large pore molecular sieve of the present invention specifically includes:

[0033] (1) Under static or dynamic stirring, mix the silicon source, boron group element compound, organic template agent, water, mineralizing agent, seed crystal and additional cationic auxiliary agent in proportion to form a homogeneous mixture, and the resulting mixture forms a reaction gel. The chemical composition of this reaction gel is (r1R1 + r2R2)(OH + X) r1+r2 :aHF:xA2O3:SiO2:wH2O, where R1 represents the positively charged group of the organic template agent, R2 represents the positively charged group of the additional cationic auxiliary agent, X represents a halogen ion, and A is Al or B; the preferred value ranges of the corresponding r1, r2, a, x and w are respectively: r1 = 0.1 - 2.0, r2 = 0.01 - 1.0, a = 0 - 2.0, x = 0 - 0.5, w = 1 - 30;

[0034] (2) Place the reaction gel under an infrared lamp or in an oven, remove the excess solvent, then transfer the reaction gel to a stainless steel autoclave, and under sealed conditions, react at a temperature of 120 - 260 °C for 2 hours - 15 days for crystallization;

[0035] (3) After washing, centrifuging and drying the crystallized product, calcine it in an air atmosphere at 400 - 650 °C for 2 - 5 hours to remove the template agent. After the product is subjected to ammonium ion exchange and calcination, a hydrogen-type ZEO-1 molecular sieve material can be obtained.

[0036] In step (1), the chemical composition of the reaction gel is (r1R1 + r2R2)(OH + X) r1+r2:aHF:xA2O3:SiO2:wH2O, A is preferably Al or B; the corresponding preferred value ranges of r1, r2, a, x and w are: r1=0.1-2.0, r2=0.01-1.0, a=0-2.0, x=0-0.5, w=1-30;.

[0037] The silicon source can be selected from at least one of silicic acid, silica gel, silica sol, tetraalkyl silicate and water glass, preferably water glass, silica sol or tetraethyl orthosilicate. The boron compound can be selected from at least one of sodium aluminate, aluminum isopropoxide, aluminum sulfate hexahydrate, aluminum hydroxide or boric acid, preferably sodium aluminate, aluminum isopropoxide, aluminum sulfate hexahydrate or boric acid. The additional cationic auxiliary agent is a small-volume cation, which can be a metal ion or an organic cation, selected from at least one of sodium ion, potassium ion, calcium ion, magnesium ion, tetramethylammonium ion and tetraethylammonium ion, and the auxiliary agent is directly introduced as a halogen salt or a basic form. The organic template is a methyl tricyclohexyl phosphine or an ethyl tricyclohexyl phosphine cation, and the template is directly introduced as a halogen salt or a basic form. The mineralizer can be OH derived from an alkaline organic template solution. - , or from additional alkaline cationic additives, or from additionally added HF or NH4F - The addition of a mineralizer can accelerate the crystallization of the molecular sieve and may be beneficial to the structural orientation. - as mineralizer) and alkaline conditions (no HF, with OH - As mineralizers), they can be rapidly crystallized to obtain highly crystalline ZEO-1 molecular sieve.

[0038] In the preparation method of the present invention, no germanium or germanium-containing compound is used.

[0039] The materials can be added and mixed in any order. For example, a boron element (Al or B) can be first added to the alkaline template solution, stirred to dissolve, and then a suitable silicon source can be added. If necessary, a mineralizer is added after stirring evenly, and the excess solvent in the system is removed by heating under an infrared lamp or in an oven to obtain the target gel.

[0040] Before preparing the reaction gel, all organic cationic templates can be exchanged into hydroxide form through ion exchange resin, and the concentration can be calibrated by 0.1M hydrochloric acid solution before use, or directly introduced in the form of chloride, bromide or iodide. In the case of introducing organic cations in the form of halogen salts, the cationic auxiliary agent needs to be introduced in the form of alkali, and the alkali source is provided by the additionally added cationic auxiliary agent; in the case of using alkaline organic template cations, the cationic auxiliary agent can be introduced in the form of halogen salts or alkalis.

[0041] In step (2), the temperature of the oven may be, for example, 80°C.

[0042] The crystallization conditions may include, for example: a crystallization temperature of 120 to 260 °C, preferably 140 to 220 °C; a crystallization time of 2 hours to 15 days, preferably 2 hours to 7 days.

[0043] The mixture in the preparation method of the present invention may further contain seed crystals. The content of the seed crystals may be 0.01 ppm by weight to 10,000 ppm by weight. The seed crystals may be ZEO-1 after removing the template agent, or may be directly synthesized ZEO-1 without removing the template agent. The presence of the seed crystals can accelerate the reaction process and reduce the reaction cost.

[0044] In step (3), washing, centrifuging, drying, and ion exchange can be carried out in any manner conventionally known in the art. For example, washing can be carried out by washing multiple times with water or ethanol; drying can be carried out by drying.

[0045] Examples

[0046] To illustrate the present invention more clearly, the following examples are listed. These examples have no limitation on the protection scope of the present invention.

[0047] Example 1

[0048] Prepare a gel for synthesizing molecular sieve according to the molar ratio of 0.5R1OH:0.1NaCl:0.02Al2O3:SiO2:10H2O. The general steps are as follows: Weigh an appropriate amount of the exchanged basic template agent solution, add 0.08 mmol (0.016 g) of aluminum isopropoxide powder thereto, stir for about half an hour to completely dissolve it, then add 2 mmol (0.417 g) of tetraethyl orthosilicate, stir at room temperature for about two hours to completely dissolve the tetraethyl orthosilicate, then add 0.2 mmol (0.012 g) of sodium chloride and 0.006 g of ZEO-1 molecular sieve seed crystals, stir evenly, place the mixed gel under an infrared lamp or in an oven at 80 °C to remove the excess solvent. Transfer the finally obtained reaction gel to a 5 ml stainless steel reaction kettle with a polytetrafluoroethylene liner, react at 190 °C for 1 day under sealed conditions, wash the product twice with water and twice with ethanol, and dry for later use. The product is directly used for X-ray powder diffraction phase identification. As Figure 1 shown, it is confirmed to be ZEO-1. ICP elemental analysis shows that the silicon-aluminum atomic ratio is 24.6. And the product is subjected to scanning electron microscope testing, and the results are as Figure 2 shown.

[0049] Example 2

[0050] Prepare the gel for synthesizing molecular sieve according to the molar ratio of 0.5R1OH:0.1KCl:0.02Al2O3:SiO2:10H2O. The general steps are as follows: Weigh an appropriate amount of the exchanged basic template agent solution, add 0.08 mmol (0.016 g) of aluminum isopropoxide powder to it, stir for about half an hour until it is completely dissolved, then add 2 mmol (0.417 g) of tetraethyl orthosilicate, stir at room temperature for about two hours until tetraethyl orthosilicate is completely dissolved, then add 0.2 mmol (0.015 g) of potassium chloride and 0.006 g of ZEO-1 molecular sieve seeds, stir evenly, place the mixed gel under an infrared lamp or in an oven at 80 °C to remove the excess solvent. Transfer the finally obtained reaction gel to a 5 ml stainless steel autoclave with a polytetrafluoroethylene liner, react at 190 °C for 1 day under sealed conditions, wash the product twice with water and twice with ethanol, and dry it for later use. The product is directly used for X-ray powder diffraction phase identification. As Figure 1 shown, it is confirmed to be ZEO-1. ICP elemental analysis shows that the silicon-aluminum atomic ratio is 24.4. And perform scanning electron microscopy test on the product. The results are as Figure 3 shown.

[0051] Example 3

[0052] Prepare the gel for synthesizing molecular sieve according to the molar ratio of 0.5R1OH:0.1N(CH3)4Cl:0.02Al2O3:SiO2:10H2O. The general steps are as follows: Weigh an appropriate amount of the exchanged basic template agent solution, add 0.08 mmol (0.016 g) of aluminum isopropoxide powder to it, stir for about half an hour until it is completely dissolved, then add 2 mmol (0.417 g) of tetraethyl orthosilicate, stir at room temperature for about two hours until tetraethyl orthosilicate is completely dissolved, then add 0.2 mmol (0.022 g) of tetramethylammonium chloride and 0.006 g of ZEO-1 molecular sieve seeds, stir evenly, place the mixed gel under an infrared lamp or in an oven at 80 °C to remove the excess solvent. Transfer the finally obtained reaction gel to a 5 ml stainless steel autoclave with a polytetrafluoroethylene liner, react at 190 °C for 1 day under sealed conditions, wash the product twice with water and twice with ethanol, and dry it for later use. The product is directly used for X-ray powder diffraction phase identification. As Figure 1 shown, it is confirmed to be ZEO-1. ICP elemental analysis shows that the silicon-aluminum atomic ratio is 23.2. And perform scanning electron microscopy test on the product. The results are as Figure 4 shown.

[0053] Example 4

[0054] Prepare the gel for synthesizing molecular sieve according to the molar ratio of 0.5R1OH:0.1NaCl:0.05Al2O3:SiO2:10H2O. The general steps are as follows: Weigh an appropriate amount of the exchanged basic template agent solution, add 0.20 mmol (0.041 g) of aluminum isopropoxide powder thereto, stir for about half an hour until it is completely dissolved, then add 2 mmol (0.417 g) of tetraethyl orthosilicate, stir at room temperature for about two hours until tetraethyl orthosilicate is completely dissolved, then add 0.2 mmol (0.012 g) of sodium chloride and 0.006 g of ZEO-1 molecular sieve seeds, stir evenly, place the mixed gel under an infrared lamp or in an oven at 80 °C to remove the excess solvent. Transfer the finally obtained reaction gel to a 5 ml stainless steel autoclave with a polytetrafluoroethylene liner, react at 190 °C for 7 days under sealed conditions, wash the product twice with water and twice with ethanol, and dry for later use. The product is directly used for X-ray powder diffraction phase identification and is confirmed to be ZEO-1. ICP elemental analysis shows that its silicon-aluminum atomic ratio is 8.1.

[0055] Example 5

[0056] Prepare the gel for synthesizing molecular sieve according to the molar ratio of 0.2R1OH:0.1NaCl:0.02Al2O3:SiO2:10H2O. The general steps are as follows: Weigh an appropriate amount of the exchanged basic template agent solution, add 0.08 mmol (0.016 g) of aluminum isopropoxide powder thereto, stir for about half an hour until it is completely dissolved, then add 2 mmol (0.417 g) of tetraethyl orthosilicate, stir at room temperature for about two hours until tetraethyl orthosilicate is completely dissolved, then add 0.2 mmol (0.012 g) of sodium chloride and 0.006 g of ZEO-1 molecular sieve seeds, stir evenly, place the mixed gel under an infrared lamp or in an oven at 80 °C to remove the excess solvent. Transfer the finally obtained reaction gel to a 5 ml stainless steel autoclave with a polytetrafluoroethylene liner, react at 190 °C for 1 day under sealed conditions, wash the product twice with water and twice with ethanol, and dry for later use. The product is directly used for X-ray powder diffraction phase identification and is confirmed to be ZEO-1. ICP elemental analysis shows that its silicon-aluminum atomic ratio is 24.7.

[0057] Example 6

[0058] Prepare the gel for synthesizing molecular sieve according to the molar ratio of 0.5R1OH:0.05NaOH:0.02Al2O3:SiO2:10H2O. The general steps are as follows: Weigh an appropriate amount of the exchanged basic template agent solution, add 0.1 mmol (0.004 g) of sodium hydroxide to it and stir evenly. Then add 0.08 mmol (0.016 g) of aluminum isopropoxide powder and stir for about half an hour until it is completely dissolved. Then add 2 mmol (0.417 g) of tetraethyl orthosilicate and stir at room temperature for about two hours until tetraethyl orthosilicate is completely dissolved. Then add 0.006 g of ZEO-1 molecular sieve seeds and stir evenly. Place the mixed gel under an infrared lamp or in an oven at 80 °C to remove the excess solvent. Transfer the finally obtained reaction gel to a 5-ml stainless-steel autoclave with a polytetrafluoroethylene liner and react at 210 °C for 8 hours under sealed conditions. Wash the product twice with water and twice with ethanol, and dry it for later use. The product is directly used for X-ray powder diffraction phase identification and is confirmed to be ZEO-1. ICP elemental analysis shows that its silicon-aluminum atomic ratio is 24.6.

[0059] Example 7

[0060] Prepare the gel for synthesizing molecular sieve according to the molar ratio of 0.5R1OH:0.1NaCl:0.10Al2O3:SiO2:10H2O. The general steps are as follows: Weigh an appropriate amount of the exchanged basic template agent solution, add 0.4 mmol (0.082 g) of aluminum isopropoxide powder to it and stir for about half an hour until it is completely dissolved. Then add 2 mmol (0.417 g) of tetraethyl orthosilicate and stir at room temperature for about two hours until tetraethyl orthosilicate is completely dissolved. Then add 0.2 mmol (0.012 g) of sodium chloride and 0.006 g of ZEO-1 molecular sieve seeds and stir evenly. Place the mixed gel under an infrared lamp or in an oven at 80 °C to remove the excess solvent. Transfer the finally obtained reaction gel to a 5-ml stainless-steel autoclave with a polytetrafluoroethylene liner and react at 210 °C for 7 days under sealed conditions. Wash the product twice with water and twice with ethanol, and dry it for later use. The product is directly used for X-ray powder diffraction phase identification and is confirmed to be ZEO-1. ICP elemental analysis shows that its silicon-aluminum atomic ratio is 4.8.

[0061] Example 8

[0062] Prepare the gel for synthesizing molecular sieve according to the molar ratio of 0.5R1OH:0.1NaCl:0.005Al2O3:SiO2:10H2O. The general steps are as follows: Weigh an appropriate amount of the exchanged basic template agent solution, add 0.01 mmol (0.002 g) of aluminum isopropoxide powder to it, stir for about half an hour to completely dissolve it, then add 2 mmol (0.417 g) of tetraethyl orthosilicate, stir at room temperature for about two hours to completely dissolve tetraethyl orthosilicate, then add 0.2 mmol (0.012 g) of sodium chloride and 0.006 g of ZEO-1 molecular sieve seeds, stir evenly, place the mixed gel under an infrared lamp or in an oven at 80 °C to remove the excess solvent. Transfer the finally obtained reaction gel to a 5 ml stainless steel autoclave with a polytetrafluoroethylene lining, react at 190 °C for 1 day under sealed conditions, wash the product twice with water and twice with ethanol, and dry for later use. The product is directly used for X-ray powder diffraction phase identification, and it is confirmed to be ZEO-1. ICP elemental analysis shows that its silicon-aluminum atomic ratio is 98.

[0063] Example 9

[0064] Prepare the gel for synthesizing molecular sieve according to the molar ratio of 0.1R1OH:0.1NaCl:0.02Al2O3:SiO2:10H2O. The general steps are as follows: Weigh an appropriate amount of the exchanged basic template agent solution, add 0.08 mmol (0.016 g) of aluminum isopropoxide powder to it, stir for about half an hour to completely dissolve it, then add 2 mmol (0.417 g) of tetraethyl orthosilicate, stir at room temperature for about two hours to completely dissolve tetraethyl orthosilicate, then add 0.2 mmol (0.012 g) of sodium chloride and 0.006 g of ZEO-1 molecular sieve seeds, stir evenly, place the mixed gel under an infrared lamp or in an oven at 80 °C to remove the excess solvent. Transfer the finally obtained reaction gel to a 5 ml stainless steel autoclave with a polytetrafluoroethylene lining, react at 190 °C for 7 days under sealed conditions, wash the product twice with water and twice with ethanol, and dry for later use. The product is directly used for X-ray powder diffraction phase identification, and it is confirmed to be ZEO-1. ICP elemental analysis shows that its silicon-aluminum atomic ratio is 24.5.

[0065] Although the present invention has been described above in conjunction with the accompanying drawings, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many variations without departing from the purpose of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A method for rapidly synthesizing ZEO-1 molecular sieve with adjustable acidity, characterized in that: The following steps are involved: 1) mixing the boron group element compound, silicon source, organic template, water, mineralizer, seed crystal and additional cationic auxiliary agent in proportion under stirring, and the obtained mixture forms a reaction gel; 2) placing the reaction gel under an infrared lamp or in an oven, removing excess solvent, and then transferring it to a stainless steel reactor and sealing it for high-temperature crystallization. After the crystallization is completed, washing the solid product to neutrality and drying it to obtain a ZEO-1 molecular sieve.

2. The method according to claim 1, characterized in that In step 1), the chemical composition of the reaction gel is (r1R1+r2R2)(OH+X) r1+r2 :aHF:xA2O3:SiO2:wH2O, wherein R1 represents the positively charged group of the organic template, R2 represents the positively charged group of the additional cationic auxiliary, X represents the halogen ion, and A is Al or B; the corresponding value ranges of r1, r2, a, x and w are: r1=0.1-2.0, r2=0.01-1.0, a=0-2.0, x=0-0.5, w=1-30.

3. The method according to claim 1, characterized in that In step 1), the silicon source is selected from at least one of silicic acid, silica gel, silica sol, tetraalkyl silicate and water glass.

4. The method according to claim 1, characterized in that: In step 1), the boron group element compound is selected from at least one of sodium aluminate, aluminum isopropoxide, aluminum sulfate hexadecahydrate, aluminum hydroxide or boric acid.

5. The method according to claim 1, characterized in that: In step 1), the additional cationic auxiliary agent is a small-volume cation, which can be a metal ion or an organic cation, selected from at least one of sodium ion, potassium ion, calcium ion, magnesium ion, tetramethylammonium ion, and tetraethylammonium ion. The auxiliary agent is directly introduced in the form of a halogen salt or a base.

6. The method according to claim 1, characterized in that In step 1), the organic template is a methyl tricyclohexylphosphine or an ethyl tricyclohexylphosphine cation, and the template is directly introduced in the form of a halogen salt or a base.

7. The method according to claim 1, characterized in that The mineralizer in step 1) can be OH - or F - , OH - Derived from basic organic template or basic additional cationic additive, F - F from additionally added HF or NH4F - .

8. The method according to claim 1, characterized in that In step 1), the mixture further comprises 0.01 ppm by weight to 10000 ppm by weight of ZEO-1 molecular sieve seed crystals.

9. The method according to claim 1, characterized in that: The crystallization conditions in step (2) include: a crystallization temperature of 120 to 260° C.; and a crystallization time of 2 hours to 15 days.

10. The method according to claim 1, characterized in that The acidity of the ZEO-1 molecular sieve synthesized in step (2) is adjustable, and the atomic ratio of silicon to aluminum and silicon to boron is adjustable within the range of 4-200.

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