Hollow y zeolite and method for synthesizing the same

Abstract

The application discloses a kind of hollow Y zeolite and its synthesis method, the zeolite crystal form is Y zeolite structure, and it is characterized as the crystal of single crystal particle hollow structure by transmission electron microscope, and the central part of crystal is cavity.The synthesis method of the hollow Y zeolite is first treated to Y zeolite in the presence of organic amine steam, after treatment, it is washed, separated and dried to obtain material, and then further reacts with inorganic alkali, aluminum source, silicon source, water to obtain hollow NaY zeolite.The problem that hollow Y zeolite cannot be synthesized in the prior art is solved, and the synthesis method is simple and easy to operate.

Description

TECHNICAL FIELD

[0001] The present application relates to a zeolite material and a method for preparing the same, in particular to a Y zeolite and a method for synthesizing the same. BACKGROUND

[0002] Hollow zeolite molecular sieve has unique physical and chemical properties, and shows broad application prospects in shape-selective adsorbents, catalysts, drug release agents and microreactors, and it is of great significance to develop hollow zeolite molecular sieve and new synthesis technology.

[0003] Patent CN105712374A discloses a preparation method of hollow USY molecular sieve, comprising the following steps: (1) preparing a directing agent; (2) preparing a mixed solution of an aluminum source, water, sodium hydroxide and water, then adding a low-silicon aluminum ratio NaY type molecular sieve and the directing agent prepared in step (1), stirring uniformly, then crystallizing the gel at a constant temperature of 90-120℃ for 12-72 hours, then cooling, washing, suction filtering and drying to obtain a Y-Y composite molecular sieve; (3) ammonium exchanging the Y-Y composite molecular sieve prepared in step (2); (4) treating the Y-Y composite molecular sieve after ammonium exchange in step (3) under hydrothermal conditions; (5) washing the composite molecular sieve obtained in step (4) under acid conditions to obtain a hollow USY molecular sieve. The method first uses a low-silicon aluminum ratio NaY type molecular sieve as a core to prepare a isomorphous composite molecular sieve, then utilizes the difference in hydrothermal stability between the low-silicon aluminum ratio NaY core and the high-silicon shell of the prepared composite molecular sieve, so that the low-silicon aluminum ratio core is changed into an amorphous structure through hydrothermal treatment, while the shell layer of high-silicon Y type molecular sieve remains its crystal structure after hydrothermal treatment. Then, the sodium oxide and amorphous aluminum oxide in the molecular sieve are successfully washed away through the acid washing process, which not only achieves the purpose of modifying the Y type molecular sieve, but also prepares a hollow USY molecular sieve.

[0004] Patent CN102491366A discloses a preparation method of hollow ZSM-5 nano zeolite, and the preparation method comprises the following steps: mixing single-dispersed ZSM-5 nano zeolite with a particle size of 100-400 nm and a silicon-aluminum molar ratio SiO2 / Al2O3 of 20 or more with an aqueous solution of an alkaline substance with a concentration of 0.05-0.5 mol / L; wherein the alkaline substance is selected from a mixture of quaternary ammonium salt and sodium hydroxide at a molar ratio of 1:1, a mixture of quaternary ammonium salt and potassium hydroxide at a molar ratio of 1:1, n-butylamine and quaternary ammonium base; stirring at 80-200 ℃ for 10-200 h, and then separating. The hollow ZSM-5 nano zeolite has a regular hollow structure, is beneficial to the transfer of reactants and products, has high crystallinity, and can be mass-produced with a simple method, low cost and high yield. Different hollow ZSM-5 nano zeolites with different silicon-aluminum ratios can be obtained by using different matrices or different treatment conditions. The size of the hollows of the hollow ZSM-5 nano zeolite can be adjusted by changing the treatment conditions.

[0005] CN104591220A provides a kind of hollow beta zeolite and its preparation method, first water, inorganic alkali, aluminum source and beta zeolite are mixed in turn stirring;Then load into airtight reactor constant temperature processing certain time to obtain hollow beta zeolite.The hollow beta zeolite prepared by the present application has the crystal structure of beta zeolite, and the crystal center is hollow state, which is suitable as an adsorbent for gas and liquid mixture separation, and can also be used as a catalyst carrier or acidic catalyst component, especially suitable for use as a special functional material.

[0006] CN1480401A discloses a liquid-solid phase preparation method of zeolite hollow microspheres, which is prepared by using mesoporous silica microspheres as a template and a silicon source, assembling nano zeolite seeds on the surface of the silica microspheres under electrostatic action, and then preparing the zeolite hollow microspheres by secondary growth in a silicon-free solution through a liquid-solid phase treatment technology. SUMMARY

[0007] In view of the deficiencies in the prior art, the main purpose of the present application is to provide a kind of hollow Y zeolite and its synthesis method, which solves the problem of difficult synthesis of hollow Y zeolite in the prior art, and the synthesis method is simple and easy to operate.

[0008] The first aspect of the present application provides a kind of hollow Y zeolite, with the following characteristics: the zeolite crystal type is Y zeolite structure, characterized by transmission electron microscope as single crystal particle hollow structure crystal, the center of crystal is cavity.

[0009] Further, the particle diameter of the hollow Y zeolite crystal is 80-650 nm, preferably 100-600 nm.

[0010] Further, the shell thickness of the hollow Y zeolite is 20-350 nm; preferably 30-300 nm.

[0011] Further, the specific surface area of the hollow Y zeolite is 280-730 m 2 / g, preferably 300-700 m 2 / g; and the pore volume is 0.09-0.31 cm 3 / g, preferably 0.1-0.3 cm 3 / g.

[0012] Further, the acid amount of the hollow Y zeolite is 0.07-0.27 mmol / g, preferably 0.08-0.25 mmol / g.

[0013] Further, the hollow Y zeolite has a silicon-aluminum oxide ratio of 3-7, preferably 3.2-6.5.

[0014] The second aspect of the present application provides a method for synthesizing a hollow Y zeolite, which comprises the following steps:

[0015] (1) treating Y zeolite in the presence of steam of an organic amine, and after the treatment, washing, separating and drying to obtain material A;

[0016] (2) mixing the material A obtained in step (1), an inorganic base, an aluminum source, a silicon source and water uniformly, and after the reaction, washing, separating, drying and calcining to obtain a hollow NaY zeolite.

[0017] The third aspect of the present application provides a method for synthesizing a hollow Y zeolite, which comprises the following steps:

[0018] (1) treating Y zeolite in the presence of steam of an organic amine, and after the treatment, washing, separating and drying to obtain material A;

[0019] (2) mixing the material A obtained in step (1), an inorganic base, an aluminum source, a silicon source and water uniformly, and after the reaction, washing, separating, drying to obtain material B;

[0020] (3) ammonium exchanging the material B, and after the final separating, drying and calcining to obtain a hollow HY zeolite.

[0021] Further, in the method for synthesizing a hollow Y zeolite, as a specific embodiment, the organic amine in step (1) is at least one of ethylenediamine, propylenediamine, butylenediamine, n-propylamine, isopropylamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide and tetrabutylammonium hydroxide, preferably at least one of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide and tetrabutylammonium hydroxide.

[0022] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the treatment in step (1) is a gas-solid two-phase reaction, and the Y zeolite is treated in the presence of steam of an organic amine. More specifically, the following method can be used: a support is arranged in a reactor, the Y zeolite is placed on the support, and a mixture of the organic amine and water is added to the lower part of the reactor support; the Y zeolite does not directly contact the liquid (the mixture of the organic amine and water); further, the mass ratio of the Y zeolite, the organic amine, and water is 8-25:8-25:100, and preferably 10-20:10-20:100.

[0023] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the treatment temperature in step (1) is 280-530°C, and preferably 300-500°C, and the treatment time is 5-12h, and preferably 6-10h.

[0024] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the washing in step (1) is washing with deionized water until the filtrate is neutral, and usually multiple washing is required.

[0025] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the separation in step (1) is solid-liquid separation, and any one of the existing methods capable of realizing solid-liquid two-phase material separation can be used, and specifically, the method of filtration can be used, and usually multiple filtration is required, and generally 1-10 times.

[0026] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the drying condition in step (1) is as follows: the drying temperature is 100-140°C; and the drying time is 5-15h.

[0027] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the Y zeolite in step (1) is selected from commercially available Y zeolite or synthesized by using the existing method for synthesizing Y zeolite. In a further preferred case, the particle diameter of the Y zeolite crystal is 80-650nm, the specific surface area is 260-760m 2 / g, the pore volume is 0.09-0.32cm 3 / g, the acid amount is 0.06-0.27mmol / g, and the oxide silicon-aluminum ratio is 3-7.

[0028] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the inorganic base in step (2) can be one or more of sodium hydroxide, potassium hydroxide, and lithium hydroxide.

[0029] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the aluminum source in step (2) can be one or more of sodium aluminate, aluminum sulfate, aluminum chloride, and aluminum nitrate.

[0030] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the silicon source in step (2) is one or more of white carbon black, silica gel, and silica sol.

[0031] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the mass ratio of the inorganic base, the aluminum source, the silicon source, the material A, and the water is 0.8-2.5:0.4-1.8:2.5-6:8-25:100, preferably 1-2:0.5-1.5:3-5:10-20:100.

[0032] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the reaction conditions in step (2) are as follows: the reaction temperature is 70-150°C, preferably 80-120°C, and the treatment time is 15-35h, preferably 20-30h.

[0033] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the washing in step (2) is washing with deionized water until the filtrate is neutral, and usually multiple washing is required.

[0034] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the separation in step (2) is solid-liquid separation, and any one of the existing methods capable of realizing the separation of solid-liquid two-phase materials can be used, and specifically, the filtration method can be used, and usually multiple filtration is required, generally 1-10 times.

[0035] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the drying temperature in step (2) is 80-150°C, and the drying time is 1-20h.

[0036] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the calcination temperature in step (2) is 400-700°C, and the calcination time is 1-20h; the calcination is carried out in an air or oxygen atmosphere.

[0037] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the ammonium exchange treatment in step (3) is carried out at least once, preferably 3-5 times.

[0038] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the ammonium exchange treatment in step (3) can use any one of the existing ammonium exchange methods in the art.

[0039] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the ammonium exchange treatment in step (3) is ion exchange treatment by mixing material B, ammonium salt and water, wherein the mass ratio of material B, ammonium salt and water is 8-25:8-25:100, preferably 10-20:10-20:100.

[0040] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the ammonium salt can be one or more of ammonium nitrate and ammonium chloride, preferably ammonium nitrate.

[0041] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the ion exchange treatment temperature is 70-100℃, preferably 80-90℃, and the ion exchange treatment time is 1-5h, preferably 2-4h.

[0042] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the washing in step (3) is washing with deionized water until the filtrate is neutral, which usually requires multiple washing.

[0043] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the separation in step (3) is solid-liquid separation, which can use any of the existing methods that can realize solid-liquid separation, and can specifically use filtration, which usually includes multiple filtration, generally 1-10 times.

[0044] Further, in the synthesis method of the hollow Y zeolite, as a specific embodiment, the drying temperature in step (3) is 80-150℃, and the drying time is 1-20h.

[0045] In the method of the present application, the calcination treatment temperature in step (3) is 400-600℃, and the calcination treatment time is 1-10h. The calcination needs to be carried out in an oxygen-containing atmosphere, such as air or oxygen.

[0046] The present application also provides a hollow Y zeolite obtained by the above synthesis method.

[0047] The hollow Y zeolite provided by the present application can be used as a carrier for drug molecules and can achieve sustained release of the loaded molecules.

[0048] The hollow Y zeolite provided by the present application can also be used as an adsorbent.

[0049] The hollow Y zeolite provided by the present application can also be used as a catalytic material.

[0050] Compared with the prior art, the Y zeolite and the synthesis method thereof provided by the present application have the following advantages:

[0051] Although the prior art discloses various preparation methods of hollow materials, the applicant finds in the research process that the existing disclosed methods for preparing hollow zeolite materials are not applicable to the preparation of hollow Y zeolite, and it is believed after analysis that because of the difference in zeolite crystal structure, the physicochemical properties are greatly different, just as the synthesis methods are not universal among different types of zeolites, the synthesis method of hollow zeolite is not universal among different types of zeolites, and different hollow structure zeolites cannot be obtained by directly replacing the types of raw materials. For example, the mesoporous structure can be made in the zeolite crystal by treating the conventional zeolite with inorganic base, and the mesoporous zeolite is obtained; however, CN104591220A can prepare hollow Beta zeolite under the joint action of inorganic base and aluminum source. Because Y zeolite has special properties, the existing method cannot treat the conventional Y zeolite to obtain hollow structure Y zeolite.

[0052] In the Y zeolite synthesis method provided by the application, the Y zeolite is first contacted with organic amine vapor for high-temperature treatment. During the treatment process, the silicon and aluminum elements in the zeolite crystal are rearranged, which may be the migration of aluminum elements to the outside of the crystal, resulting in the increase of aluminum content outside the crystal and the decrease of aluminum content inside the crystal, causing the gradient distribution of aluminum elements in the crystal, which is beneficial to the formation of hollow structure. And in the presence of organic amine, the crystal structure remains relatively complete and will not be severely damaged.

[0053] In the Y zeolite synthesis method provided by the application, the Y zeolite after modification treatment is mixed with other raw materials (inorganic base, aluminum source, silicon source) to occur secondary crystallization reaction, and the material ratio of other raw materials is greatly different from the material ratio of the existing preparation Y zeolite, which is not in the effective range of the material ratio of the existing conventional hydrothermal synthesis reaction. The secondary reaction in the application is different from the existing hydrothermal synthesis reaction of zeolite. In the secondary reaction process in the application, the inorganic base, aluminum source and silicon source react with the treated Y zeolite, the aluminum elements enter the outside of the zeolite crystal, and the inside of the zeolite crystal dissolves, thereby forming a hollow pattern. In this process, the silicon source basically does not enter the zeolite crystal framework. It is believed after research that in the synthesis method of the application, the silicon source only plays a role in stabilizing the system, and in the absence of silicon source, the zeolite cannot be effectively converted into a hollow structure. And the HY zeolite material synthesized by the application has an increased acid amount compared with the original material, which can load more molecules in the loading and release process of molecules such as drugs, and can also increase the release time.

[0054] In summary, in the Y zeolite synthesis method provided by the application, two means of treating Y zeolite with organic amine vapor and secondary reaction of the treated Y zeolite with inorganic base, aluminum source, silicon source and water are combined to provide a new method for preparing hollow Y zeolite, and a new structure of hollow Y zeolite is obtained. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 Transmission electron microscope photographs of samples obtained for Example 1 were taken.

[0056] Figure 2 Transmission electron microscope photographs of samples obtained for Comparative Example 1 were taken.

[0057] Figure 3 XRD spectra of samples obtained for Example 1 were taken.

[0058] Figure 4 XRD spectra of samples obtained for Comparative Example 1 were taken. DETAILED DESCRIPTION

[0059] The technical solutions and technical effects of the present application are further illustrated below by means of the accompanying drawings and in conjunction with the detailed description, but are not limited to the following embodiments.

[0060] In the present application, the pore structure of the zeolite material is characterized by N2 adsorption-desorption, which is tested by a physical adsorption instrument of Micromeritics Company, USA. Before testing, the sample is treated in vacuum at 300℃ for more than 4h. The specific surface area, pore size and other parameters are calculated according to the BET and BJH formulas.

[0061] In the present application, the phase structure and crystallinity of the zeolite material are characterized by X-ray diffraction, which is tested by a D / max2500 X-ray diffractometer of Rigaku, Japan. The Cu target, Kα radiation source, graphite monochromator, tube voltage 40kV, tube current 80mA, scanning range 5°-40°, step size 0.1°, and scanning speed 1° / min.

[0062] In the present application, the acid amount of the zeolite material is measured by ammonia temperature programmed desorption, which is tested by an AutoChem II 2920 chemical adsorption instrument of Micromeritics Company, USA. First, the sample is heated to 550℃ at a rate of 10℃ / min under the protection of helium and kept for 1h; then, it is cooled to room temperature (25℃) at a rate of 10℃ / min, replaced by ammonia and adsorbed for 1h; and then, it is heated to 600℃ at a rate of 10℃ / min under the protection of helium.

[0063] In the present application, the crystal morphology of the zeolite material is characterized by transmission electron microscopy, which is tested by a high-resolution transmission electron microscope of JEOL Company, Japan. The instrument model is JEM-2200FS field emission ultra-high-resolution transmission electron microscope, the acceleration voltage is 200KV, and the point resolution is 0.19nm.

[0064] In the present application, all the chemical reagents used are analytical pure chemical reagents, which can be obtained by purchasing commercially available products.

[0065] In this paper, the Y zeolite crystal size is about 200 nm, the oxide silicon aluminum ratio is 5.23, the specific surface area is 697 m 2 / g, and the acid amount is 0.176 mmol / g.

[0066] Example 1

[0067] (1) According to the mass ratio of Y zeolite, tetraethylammonium hydroxide, and water of 15:13:100, the Y zeolite is placed on the support in the reaction kettle, and water and tetraethylammonium hydroxide are added to the bottom of the reaction kettle. Then 400℃ reaction for 8h. After the reaction is completed, the obtained solid is washed with water and filtered for multiple times, and then dried at 120℃ for 10h to obtain material A.

[0068] (2) Then according to the proportion (mass ratio of inorganic base, aluminum source, silicon source, material A, water = 1.7:1.1:4:12:100) sodium hydroxide, aluminum nitrate, white carbon black, material A, and deionized water are added and mixed uniformly. Then put into a sealed reaction kettle and react at 100℃ for 25h. After the reaction is completed, the obtained solid sample is filtered for multiple times, and then dried at 120℃ for 10h to obtain material B.

[0069] (3) Then according to the proportion (mass ratio of ammonium nitrate, material B, water = 16:15:100) ammonium nitrate and deionized water are added to material B and mixed uniformly, and then treated at 85℃ for 3h, and the cycle is treated for 3 times.

[0070] (4) After the end, the obtained solid sample is filtered for multiple times, and then dried at 120℃ for 10h. Finally, the obtained sample is calcined at 500℃ in air for 10h, and the sample is numbered as C1.

[0071] The crystal structure of the prepared sample belongs to Y zeolite, and the crystal morphology is a hollow shell structure.

[0072] Example 2

[0073] (1) According to the mass ratio of Y zeolite, organic matter, and water of 10:10:100, the Y zeolite is placed on the support in the reaction kettle, and water and tetraethylammonium hydroxide are added to the bottom of the reaction kettle. Then 300℃ reaction for 10h. After the reaction is completed, the obtained solid sample is washed with water and filtered for multiple times, and then dried at 120℃ for 10h to obtain material A.

[0074] (2) Then according to the proportion (mass ratio of inorganic base, aluminum source, silicon source, material A, water = 1:0.5:3:10:100) sodium hydroxide, aluminum nitrate, white carbon black, material A, and deionized water are added and mixed uniformly. Then put into a sealed reaction kettle and react at 80℃ for 20h. After the reaction is completed, the obtained solid sample is filtered for multiple times, and then dried at 120℃ for 10h to obtain material B.

[0075] (3) Then, ammonium nitrate, deionized water were added to material B according to the ratio (mass ratio of ammonium nitrate, material B, water = 10:10:100) and mixed uniformly. Then, 90℃ treatment for 2h. Cycle treatment for 3 times.

[0076] (4) After the end, the obtained solid sample was filtered for multiple times, and then dried at 120℃ for 10h. Finally, the obtained sample was calcined at 500℃ in air for 10h, and the sample was numbered as C2.

[0077] The crystal structure of the prepared sample belongs to Y zeolite, and the crystal morphology is a hollow shell structure.

[0078] Example 3

[0079] (1) Y zeolite was placed on the support in the reaction kettle according to the mass ratio of Y zeolite, tetrapropylammonium hydroxide, water = 20:20:100, water and tetrapropylammonium hydroxide were added to the bottom of the reaction kettle. Then, 500℃ reaction for 6h. After the end of the reaction, the obtained solid sample was washed with water and filtered for multiple times, and then dried at 120℃ for 10h to obtain material A.

[0080] (2) Then, sodium hydroxide, aluminum nitrate, white carbon black, material A, deionized water were added according to the ratio (mass ratio of inorganic base, aluminum source, silicon source, material A, water = 2:1.5:5:20:100) and mixed uniformly. Then, 120℃ reaction for 30h in a sealed reaction kettle. After the end of the reaction, the obtained solid sample was filtered for multiple times, and then dried at 120℃ for 10h to obtain material B.

[0081] (3) Then, ammonium nitrate, deionized water were added to material B according to the ratio (mass ratio of ammonium nitrate, material B, water = 20:20:100) and mixed uniformly. Then, 80℃ treatment for 4h. Cycle treatment for 3 times.

[0082] (4) After the end, the obtained solid sample was filtered for multiple times, and then dried at 120℃ for 10h. Finally, the obtained sample was calcined at 500℃ in air for 10h, and the sample was numbered as C3.

[0083] The crystal structure of the prepared sample belongs to Y zeolite, and the crystal morphology is a hollow shell structure.

[0084] Example 4

[0085] (1) Y zeolite was placed on the support in the reaction kettle according to the mass ratio of Y zeolite, tetrabutylammonium hydroxide, water = 13.5:12.3:100, water and tetrabutylammonium hydroxide were added to the bottom of the reaction kettle. Then, 420℃ reaction for 8h. After the end of the reaction, the obtained solid sample was washed with water and filtered for multiple times, and then dried at 120℃ for 10h to obtain material A.

[0086] (2) Then, according to the proportion (mass ratio of inorganic base, aluminum source, silicon source, material A, water = 1.2: 1.1: 4.2: 12.5: 100), sodium hydroxide, aluminum chloride, white carbon black, material A, and deionized water were added and mixed uniformly. Then, it was loaded into a sealed reaction kettle and reacted at 112°C for 22h. After the reaction was completed, the obtained solid sample was filtered multiple times, and then dried at 120°C for 10h to obtain material B.

[0087] (3) Then, according to the proportion (mass ratio of ammonium nitrate, material B, water = 16.2: 15.3: 100), ammonium nitrate and deionized water were added to material B and mixed uniformly. Then, it was treated at 83°C for 3h. The cycle treatment was repeated 3 times.

[0088] (4) After the end, the obtained solid sample was filtered multiple times, and then dried at 120°C for 10h. Finally, it was calcined in air at 500°C for 10h, and the obtained sample was numbered as C4.

[0089] The crystal structure of the prepared sample belongs to Y zeolite, and the crystal morphology is a hollow shell structure.

[0090] Example 5

[0091] (1) According to the mass ratio of Y zeolite, tetraethylammonium hydroxide, and water 11.5: 17.3: 100, Y zeolite was placed on the support in the reaction kettle, and water and tetraethylammonium hydroxide were added to the bottom of the reaction kettle. Then, it was reacted at 430°C for 7h. After the reaction was completed, the obtained solid sample was washed with water and filtered multiple times, and then dried at 120°C for 10h to obtain material A.

[0092] (2) Then, according to the proportion (mass ratio of inorganic base, aluminum source, silicon source, material A, water = 1.2: 1.3: 4.5: 13.5: 100), sodium hydroxide, aluminum sulfate, white carbon black, material A, and deionized water were added and mixed uniformly. Then, it was loaded into a sealed reaction kettle and reacted at 90°C for 25h. After the reaction was completed, the obtained solid sample was filtered multiple times, and then dried at 120°C for 10h to obtain material B.

[0093] (3) Then, according to the proportion (mass ratio of ammonium nitrate, material B, water = 16.5: 11: 100), ammonium nitrate and deionized water were added to material B and mixed uniformly. Then, it was treated at 85°C for 3h. The cycle treatment was repeated 3 times.

[0094] (4) After the end, the obtained solid sample was filtered multiple times, and then dried at 120°C for 10h. Finally, it was calcined in air at 500°C for 10h, and the obtained sample was numbered as C5.

[0095] The crystal structure of the prepared sample belongs to Y zeolite, and the crystal morphology is a hollow shell structure.

[0096] Comparative Example 1

[0097] The Y zeolite is not treated.

[0098] (1) The Y zeolite, sodium hydroxide, aluminum nitrate, white carbon black and deionized water are mixed uniformly in a ratio (mass ratio of inorganic base, aluminum source, silicon source, Y zeolite, water = 1.7:1.1:4:12:100). Then, the mixture is loaded into a sealed reaction kettle and reacted at 100°C for 25h. After the reaction, the obtained solid sample is filtered multiple times, and then dried at 120°C for 10h to obtain material B.

[0099] (2) Then, ammonium nitrate and deionized water are added to the material B in a ratio (mass ratio of ammonium nitrate, material B, water = 16:15:100) and mixed uniformly. Then, the mixture is treated at 85°C for 3h. The treatment is repeated for 3 cycles.

[0100] (3) After the treatment, the obtained solid sample is filtered multiple times, and then dried at 120°C for 10h. Finally, the sample is calcined in air at 500°C for 10h, and the obtained sample is numbered as C6.

[0101] The crystal structure of the prepared sample belongs to Y zeolite, but is not a hollow structure. It is proved that the step (1) of the present application is an indispensable step.

[0102] Comparative Example 2

[0103] (1) The Y zeolite is placed on a support in a reaction kettle in a ratio (mass ratio of Y zeolite, tetraethylammonium hydroxide, water = 15:13:100), and water and tetraethylammonium hydroxide are added to the bottom of the reaction kettle. Then, the mixture is reacted at 400°C for 8h. After the reaction, the obtained solid is washed with water and filtered multiple times, and then dried at 120°C for 10h to obtain material A.

[0104] (2) Then, sodium hydroxide, white carbon black, material A and deionized water are added in a ratio (mass ratio of inorganic base, silicon source, material A, water = 1.7:4:12:100) and mixed uniformly. Then, the mixture is loaded into a sealed reaction kettle and reacted at 100°C for 25h. After the reaction, the obtained solid sample is filtered multiple times, and then dried at 120°C for 10h to obtain material B.

[0105] (3) Then, ammonium nitrate and deionized water are added to the material B in a ratio (mass ratio of ammonium nitrate, material B, water = 16:15:100) and mixed uniformly. Then, the mixture is treated at 85°C for 3h. The treatment is repeated for 3 cycles.

[0106] (4) After the treatment, the obtained solid sample is filtered multiple times, and then dried at 120°C for 10h. Finally, the sample is calcined in air at 500°C for 10h, and the obtained sample is numbered as C7.

[0107] The crystal structure of the prepared sample belongs to Y zeolite, but is not a hollow structure. It is proved that the aluminum source in the step (3) of the present application is indispensable.

[0108] Comparative Example 3

[0109] (1) Y zeolite was placed on a support in a reaction kettle in a proportion of 15:13:100 of Y zeolite, tetraethylammonium hydroxide, and water, and water and tetraethylammonium hydroxide were added to the bottom of the reaction kettle. Then, 400°C was reacted for 8h. After the reaction, the obtained solid was washed with water and filtered several times, and then dried at 120°C for 10h to obtain material A.

[0110] (2) Then, sodium hydroxide, aluminum nitrate, material A, and deionized water were added in a proportion of 1.7:1.1:12:100 of inorganic base, aluminum source, material A, and water, and mixed uniformly. Then, a closed reaction kettle was loaded and reacted at 100°C for 25h. After the reaction, the obtained solid sample was filtered several times, and then dried at 120°C for 10h to obtain material B.

[0111] (3) Then, ammonium nitrate and deionized water were added to material B in a proportion of 16:15:100 of ammonium nitrate, material B, and water, and mixed uniformly. Then, 85°C was treated for 3h, and the cycle was treated 3 times.

[0112] (4) After the end, the obtained solid sample was filtered several times, and then dried at 120°C for 10h. Finally, 500°C was calcined in air for 10h, and the obtained sample was numbered as C8.

[0113] The crystal structure of the prepared sample belongs to Y zeolite, but is not a hollow structure. It is indicated that the silicon source in step (3) of the present application is indispensable.

[0114] Comparative Example 4

[0115] (1) Y zeolite was placed on a support in a reaction kettle in a proportion of 15:13:100 of Y zeolite, tetraethylammonium hydroxide, and water, and water and tetraethylammonium hydroxide were added to the bottom of the reaction kettle. Then, 400°C was reacted for 8h. After the reaction, the obtained solid was washed with water and filtered several times, and then dried at 120°C for 10h to obtain material A.

[0116] (2) Then, sodium hydroxide, aluminum nitrate, white carbon black, material A, and deionized water were added in a proportion of 3.2:3:16:1.6:100 of inorganic base, aluminum source, silicon source, material A, and water, and mixed uniformly. Then, a closed reaction kettle was loaded and reacted at 100°C for 50h. After the reaction, the obtained solid sample was filtered several times, and then dried at 120°C for 10h to obtain material B.

[0117] (3) Then, ammonium nitrate and deionized water were added to material B in a proportion of 16:15:100 of ammonium nitrate, material B, and water, and mixed uniformly. Then, 85°C was treated for 3h, and the cycle was treated 3 times.

[0118] (4) After the reaction, the obtained solid sample was filtered several times, and then dried at 120°C for 10h. Finally, the sample was calcined at 500°C in air for 10h, and the obtained sample was numbered as C9.

[0119] The crystal structure of the prepared sample belongs to Y zeolite, which belongs to the conventional morphology of Y zeolite.

[0120] Comparative Example 5

[0121] (1) Y zeolite was placed on a support in a reaction kettle according to the mass ratio of Y zeolite, tetraethylammonium hydroxide and water of 15:13:100, and water and tetraethylammonium hydroxide were added to the bottom of the reaction kettle. Then, 100°C reaction was carried out for 8h. After the reaction, the obtained solid was washed with water and filtered several times, and then dried at 120°C for 10h to obtain material A.

[0122] (2) Then, sodium hydroxide, aluminum nitrate, white carbon black, material A and deionized water were added according to the mass ratio of inorganic base, aluminum source, silicon source, material A and water = 1.7:1.1:4:12:100, and mixed uniformly. Then, it was loaded into a sealed reaction kettle and reacted at 100°C for 25h. After the reaction, the obtained solid sample was filtered several times, and then dried at 120°C for 10h to obtain material B.

[0123] (3) Then, ammonium nitrate and deionized water were added to material B according to the mass ratio of ammonium nitrate, material B and water = 16:15:100, and mixed uniformly, and then treated at 85°C for 3h, and the cycle was repeated for 3 times.

[0124] (4) After the reaction, the obtained solid sample was filtered several times, and then dried at 120°C for 10h. Finally, the sample was calcined at 500°C in air for 10h, and the obtained sample was numbered as C10.

[0125] The crystal structure of the prepared sample belongs to Y zeolite, which belongs to the conventional morphology of Y zeolite.

[0126] Comparative Example 6

[0127] (1) Y zeolite was placed on a support in a reaction kettle according to the mass ratio of Y zeolite, tetraethylammonium hydroxide and water of 15:13:100, and water and tetraethylammonium hydroxide were added to the bottom of the reaction kettle. Then, 400°C reaction was carried out for 8h. After the reaction, the obtained solid was washed with water and filtered several times, and then dried at 120°C for 10h to obtain material A.

[0128] (2) Then, sodium hydroxide, aluminum nitrate, white carbon black, material A and deionized water were added according to the mass ratio of inorganic base, aluminum source, silicon source, material A and water = 1.7:1.1:4:12:100, and mixed uniformly. Then, it was loaded into a sealed reaction kettle and reacted at 200°C for 25h. After the reaction, the obtained solid sample was filtered several times, and then dried at 120°C for 10h to obtain material B.

[0129] (3) Then, ammonium nitrate was added to the material B in proportion (mass ratio of ammonium nitrate, material B, water = 16:15:100), and mixed uniformly, and then treated at 85°C for 3h, and the cycle was repeated for 3 times.

[0130] (4) After the end, the obtained solid sample was filtered for several times, and then dried at 120°C for 10h. Finally, the sample was calcined in air at 500°C for 10h, and the obtained sample was numbered as C11.

[0131] The crystal structure of the prepared sample belongs to Y zeolite, which belongs to the conventional morphology of Y zeolite.

[0132] Table 1: Physicochemical properties of samples obtained in each example and comparative example

[0133]

[0134] Note: The sample obtained in Example 1 is used as a reference, and its crystallinity is set to 100%. The relative crystallinity of all other samples is obtained by comparison with the crystallinity of the reference.

Claims

1. A hollow Y-zeolite, characterized by the following features: the zeolite crystal form is Y-zeolite, and transmission electron microscopy reveals it to be a hollow crystal structure consisting of single crystal particles, with a cavity at the center of the crystal; the synthesis methods for hollow Y-zeolite include two methods, wherein... The first method for synthesizing hollow Y zeolite includes the following steps: (1) Y zeolite is treated in the presence of organic amine vapor, and after treatment, it is washed, separated and dried to obtain material A; the organic amine in step (1) is at least one of ethylenediamine, propylenediamine, butanediamine, n-propylamine, isopropylamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide; the treatment temperature is 280-530℃ and the treatment time is 5-12h; (2) The material A, inorganic alkali, aluminum source, silicon source and water obtained in step (1) are mixed evenly. After reaction, the mixture is washed, separated, dried and calcined to obtain hollow NaY zeolite. The mass ratio of inorganic alkali, aluminum source, silicon source, material A and water is 0.8~2.5:0.4~1.8:2.5~6:8~25:

100. The reaction temperature is 70~150℃ and the processing time is 15~35h. The second method for synthesizing hollow Y-zeolite includes the following steps: (1) Y zeolite is treated in the presence of organic amine vapor, and after treatment, it is washed, separated and dried to obtain material A; the organic amine in step (1) is at least one of ethylenediamine, propylenediamine, butanediamine, n-propylamine, isopropylamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide; the treatment temperature is 280-530℃ and the treatment time is 5-12h; (2) Mix the material A obtained in step (1), inorganic alkali, aluminum source, silicon source and water evenly, and after reaction, wash, separate and dry to obtain material B; the mass ratio of inorganic alkali, aluminum source, silicon source, material A and water is 0.8~2.5:0.4~1.8:2.5~6:8~25:100; the reaction temperature is 70~150℃ and the processing time is 15~35h; (3) Material B is subjected to ammonium exchange treatment, and finally obtained hollow HY zeolite after separation, drying and calcination.

2. The hollow Y-zeolite according to claim 1, characterized in that: The particle diameter of hollow Y zeolite crystals is 80–650 nm.

3. The hollow Y-zeolite according to claim 1, characterized in that: The particle diameter of hollow Y zeolite crystals is 100–600 nm.

4. The hollow Y-zeolite according to claim 1, characterized in that: The shell thickness of hollow Y zeolite is 20–350 nm.

5. The hollow Y-zeolite according to claim 1, characterized in that: The shell thickness of hollow Y zeolite is 30–300 nm.

6. The hollow Y-zeolite according to claim 1, characterized in that: The specific surface area of ​​hollow Y zeolite is 280–730 m². 2 / g; pore volume is 0.09~0.31cm³ 3 / g.

7. The hollow Y-zeolite according to claim 1, characterized in that: The specific surface area of ​​hollow Y zeolite is 300–700 m². 2 / g; pore volume is 0.1~0.3cm 3 / g.

8. The hollow Y-zeolite according to claim 1, characterized in that: The acidity of hollow Y zeolite is 0.07–0.27 mmol / g.

9. The hollow Y-zeolite according to claim 1, characterized in that: The acidity of hollow Y zeolite is 0.08–0.25 mmol / g.

10. The hollow Y-zeolite according to claim 1, characterized in that: The silica-alumina ratio of the oxide in hollow Y zeolite is 3–7.

11. The hollow Y-zeolite according to claim 1, characterized in that: The silica-alumina ratio of the oxide in hollow Y zeolite is 3.2–6.

5.

12. A method for synthesizing the hollow Y zeolite according to any one of claims 1-11, the method comprising the following steps: (1) Y zeolite is treated in the presence of organic amine vapor, and after treatment, it is washed, separated and dried to obtain material A; the organic amine in step (1) is at least one of ethylenediamine, propylenediamine, butanediamine, n-propylamine, isopropylamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide; the treatment temperature is 280-530℃ and the treatment time is 5-12h; (2) The material A, inorganic alkali, aluminum source, silicon source and water obtained in step (1) are mixed evenly. After reaction, hollow NaY zeolite is obtained by washing, separating, drying and calcining. The mass ratio of inorganic alkali, aluminum source, silicon source, material A and water is 0.8~2.5:0.4~1.8:2.5~6:8~25:

100. The reaction temperature is 70~150℃ and the treatment time is 15~35h.

13. A method for synthesizing hollow Y zeolite according to any one of claims 1-11, the method comprising the following steps: (1) Y zeolite is treated in the presence of organic amine vapor, and after treatment, it is washed, separated and dried to obtain material A; the organic amine in step (1) is at least one of ethylenediamine, propylenediamine, butanediamine, n-propylamine, isopropylamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide; the treatment temperature is 280-530℃ and the treatment time is 5-12h; (2) Mix the material A obtained in step (1), inorganic alkali, aluminum source, silicon source and water evenly, and after reaction, wash, separate and dry to obtain material B; the mass ratio of inorganic alkali, aluminum source, silicon source, material A and water is 0.8~2.5:0.4~1.8:2.5~6:8~25:100; the reaction temperature is 70~150℃ and the processing time is 15~35h; (3) Material B is subjected to ammonium exchange treatment, and finally obtained hollow HY zeolite after separation, drying and calcination.

14. The method for synthesizing hollow Y zeolite according to claim 12 or 13, characterized in that: The organic amine in step (1) is at least one of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide.

15. The method for synthesizing hollow Y zeolite according to claim 12 or 13, characterized in that: The treatment in step (1) is a gas-solid two-phase reaction. Y zeolite is treated in the presence of organic amine vapor. The following method is used: a support is provided in the reactor, Y zeolite is placed on the support, and a mixture of organic amine and water is added to the lower part of the reactor support. Y zeolite and the mixture of organic amine and water do not come into direct contact. The mass ratio of Y zeolite, organic amine and water is 8-25:8-25:

100.

16. The method for synthesizing hollow Y zeolite according to claim 15, characterized in that: The mass ratio of Y zeolite, organic amine, and water is 10-20:10-20:

100.

17. The method for synthesizing hollow Y zeolite according to claim 12 or 13, characterized in that: The processing temperature in step (1) is 300-500℃ and the processing time is 6-10 h.

18. The method for synthesizing hollow Y zeolite according to claim 12 or 13, characterized in that: The drying conditions in step (1) are as follows: drying temperature is 100-140℃; drying time is 5-15h.

19. The method for synthesizing hollow Y zeolite according to claim 12 or 13, characterized in that: The inorganic base in step (2) is one or more of sodium hydroxide, potassium hydroxide, and lithium hydroxide.

20. The method for synthesizing hollow Y zeolite according to claim 12 or 13, characterized in that: The aluminum source in step (2) is one or more of sodium aluminate, aluminum sulfate, aluminum chloride, and aluminum nitrate.

21. The method for synthesizing hollow Y zeolite according to claim 12 or 13, characterized in that: The silicon source in step (2) is one or more of silica, silica gel, and silica sol.

22. The method for synthesizing hollow Y zeolite according to claim 12 or 13, characterized in that: The mass ratio of inorganic alkali, aluminum source, silicon source, material A, and water is 1-2:0.5-1.5:3-5:10-20:

100.

23. The method for synthesizing hollow Y zeolite according to claim 12 or 13, characterized in that: The reaction conditions in step (2) are as follows: the reaction temperature is 80-120℃ and the treatment time is 20-30h.

24. The method for synthesizing hollow Y zeolite according to claim 12 or 13, characterized in that: The drying temperature in step (2) is 80-150℃ and the drying time is 1-20h.

25. The method for synthesizing hollow Y zeolite according to claim 12, characterized in that: The roasting temperature in step (2) is 400-700℃ and the roasting time is 1-20h; the roasting is carried out in an air or oxygen atmosphere.

26. The method for synthesizing hollow Y zeolite according to claim 13, characterized in that: The ammonium exchange treatment in step (3) involves mixing material B, ammonium salt, and water for ion exchange treatment, wherein the mass ratio of material B, ammonium salt, and water is 8-25:8-25:

100.

27. The method for synthesizing hollow Y zeolite according to claim 13, characterized in that: The ammonium exchange treatment in step (3) involves mixing material B, ammonium salt, and water for ion exchange treatment, wherein the mass ratio of material B, ammonium salt, and water is 10-20:10-20:

100.

28. The method for synthesizing hollow Y zeolite according to claim 13, characterized in that: The ammonium salt is one or more of ammonium nitrate and ammonium chloride.

29. The method for synthesizing hollow Y zeolite according to claim 13, characterized in that: The ion exchange treatment temperature is 70–100℃, and the ion exchange treatment time is 1–5 h.

30. The method for synthesizing hollow Y zeolite according to claim 13, characterized in that: The ion exchange treatment temperature is 80–90℃, and the ion exchange treatment time is 2–4 h.

31. The method for synthesizing hollow Y zeolite according to claim 13, characterized in that: The drying temperature in step (3) is 80-150℃ and the drying time is 1-20h; the calcination temperature in step (3) is 400-600℃ and the calcination time is 1-10h; calcination needs to be carried out under an oxygen-containing atmosphere.

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