Synthesis method and application of zeolite self-supporting micro-nano reactor

Abstract

The invention belongs to the field of zeolite synthesis, the synthesized zeolite is micron crystal particles formed by highly staggered symbiotic zeolite sheets, namely a zeolite self-supporting micro-nano reactor, and the synthesis method comprises the following steps: uniformly mixing a silicon source, an aluminum source, a metal source, inorganic salt, an organic template agent and deionized water to prepare gel; and sealing the gel in a reaction kettle for pretreatment, and performing crystallization and post-treatment to obtain the zeolite self-supporting micro-nano reactor. The synthesis method has the advantages of simple steps, easiness in operation, high repeatability, low cost, environment friendliness and the like. The zeolite self-supporting micro-nano reactor prepared by the invention has the characteristics of high external specific surface area, high active site content, high active site accessibility, high chemical stability, high structural stability and the like, can be directly used as a catalyst, can also be used as a catalyst carrier, and has great application value.

Description

Technical Field

[0001] The invention belongs to the field of zeolite synthesis, and in particular relates to a synthesis method and application of a zeolite self-supporting micro-nano reactor. Background Art

[0002] Zeolite molecular sieve is an important type of microporous crystalline material, which is widely used in catalysis, adsorption separation, ion exchange and other fields. It occupies an important strategic position in the national economy. Its synthesis usually adopts the hydrothermal method.

[0003] Compared with the traditional three-dimensional zeolite, the crystal size of two-dimensional zeolite (zeolite flakes) is significantly reduced in at least one direction, which greatly enhances the diffusivity of molecules and the accessibility of catalytic active sites. Therefore, it has great advantages in the field of catalysis. It can be synthesized by hydrothermal method, surfactant template method, or by hydrolysis of three-dimensional zeolite, but the main problem of two-dimensional zeolite is that its stability is generally poor. Summary of the invention

[0004] In view of the problem of poor stability of existing two-dimensional zeolites, the purpose of the present invention is to provide a method for synthesizing a zeolite self-supporting micro-nano reactor. The zeolite self-supporting micro-nano reactor is a micron crystal particle composed of highly interlaced zeolite platelets, which has the characteristics of high external specific surface area, high active site content, high active site accessibility, high chemical stability, high structural stability, etc. It can be used directly as a catalyst or as a catalyst carrier.

[0005] The technical solution of the present invention is: a method for synthesizing a zeolite self-supporting micro-nano reactor, comprising the following steps:

[0006] Step 1: Aluminum source, silicon source, metal source, inorganic salt, organic template and deionized water are stirred and mixed at room temperature to form gel 1, gel 1 is transferred to a reaction kettle that can rotate around a horizontal axis and sealed, and treated at a temperature of 30 to 130° C. and a rotation speed of 10 to 50 rpm for 6 to 48 hours to obtain gel 2;

[0007] Step 2, crystallizing the gel 2 at a temperature of 140-250° C. in a stepwise variable speed crystallization manner, wherein the stepwise variable speed crystallization manner includes first crystallizing at a rotation speed of 55-200 rpm for 24-240 hours, then crystallizing at a rotation speed of 0-200 rpm for 24-120 hours, filtering, and drying to obtain a crude product;

[0008] Step 3: directly treating the crude product with acid, or first treating it with acid and then calcining it, or directly calcining it to obtain a zeolite self-supporting micro-nano reactor.

[0009] Preferably, in step 1, the aluminum source is one or more of sodium aluminate, aluminum isopropoxide, aluminum oxide, aluminum chloride, aluminum hydroxide, pseudo-boehmite, and boehmite;

[0010] The silicon source is an inorganic silicon source and / or an organic silicon source, wherein the inorganic silicon source is one or more of fumed silica, silica sol, ethyl orthosilicate, water glass, and silicon tetrachloride, and the organic silicon source is one or more of dimethyldiethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, mercaptopropyltriethoxysilane, aminopropyltriethoxysilane, hexadecyltriethoxysilane, and bis(triethoxysilyl)methane;

[0011] The inorganic salt is one or more of a sodium salt, a potassium salt, and an ammonium salt; the sodium salt is one or more of sodium hydroxide, sodium aluminate, sodium chloride, sodium carbonate, sodium nitrate, sodium sulfate, and sodium sulfite; the potassium salt is one or more of potassium chloride and potassium hydroxide; and the ammonium salt is one or more of ammonium chloride, ammonium nitrate, and ammonium fluoride. Further, the silicon source is an inorganic silicon source or a mixture of an inorganic silicon source and an organic silicon source.

[0012] Preferably, in step 1, the metal source is one or more of tin tetrachloride, dimethyltin dichloride, zirconium chloride, zirconium nitrate, nickel nitrate, zinc acetate, zinc chloride, ammonium metavanadate, iridium trichloride, n-butyl titanate, ferric chloride, ferric nitrate, manganese acetate, manganese chloride, cobalt acetate, cobalt chloride, cobalt nitrate, copper sulfate, and chromium nitrate;

[0013] The organic template is one or more of piperidine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, cyclohexylamine, ethylene glycol, polyethylene glycol, isopropanol, tetrahydrofuran, cyclohexane, pyrrolidine, isopropylamine, hexamethyleneimine, ethylenediamine, dibutylamine, n-butylamine, 1,8-diaminooctane, N,N-diethyl cis-2,6-dimethylpiperidine, 1,3-dimethylimidazole, diethylenetriamine, and tetraethylenepentamine.

[0014] Preferably, in step one, the molar ratio of each reaction raw material is aluminum source: inorganic silicon source: organic silicon source: metal source: inorganic salt: organic template: deionized water = 1: (5-50): (0-10): (0-1): (0.1-5): (4-10): (60-900), wherein: the aluminum source is calculated as Al2O3, the inorganic silicon source and the organic silicon source are both calculated as SiO2, the metal source is calculated as metal M, and the inorganic salt is calculated as the sodium, potassium or ammonium contained.

[0015] Preferably, in step 1, the reaction kettle is sealed and fixed in a reactor having a heating function and rotatable around a horizontal axis, and both the temperature and the rotation speed can be controlled.

[0016] Preferably, in step 2, filtering is performed by suction filtration or centrifugation, and the drying is performed at 80 to 105° C. for 12 to 24 hours.

[0017] Preferably, in step 3, the acid treatment comprises mixing the crude product with 2-4 mol / L hydrochloric acid at a weight ratio of 1:40-60, refluxing at a temperature of 60-80°C for 15-20 hours, and then filtering, washing, and drying; the calcination comprises calcining at 550-600°C for 4-10 hours. In step 3 of the present invention, the crude product can be directly acid-treated or directly calcined to obtain a zeolite self-supporting micro-nano reactor, or the crude product can be first acid-treated and then calcined to obtain a zeolite self-supporting micro-nano reactor.

[0018] Preferably, in step 1, the gel 2 is obtained by treating at a temperature of 60 to 120° C. and a rotation speed of 20 to 30 rpm for 12 to 48 hours.

[0019] Preferably, in step 2, the gel 2 is subjected to stepwise variable speed crystallization at a temperature of 180 to 200° C. The stepwise variable speed crystallization includes first crystallizing at a rotation speed of V1 for 72 to 120 hours and then crystallizing at a rotation speed of V2 for 72 to 120 hours, and V1 and V2 satisfy the following relationship:

[0020] When V1 is 55 rpm ≤ V1 ≤ 100 rpm, V2 is 55 rpm ≤ V2 ≤ 200 rpm;

[0021] When the value of V1 is 100 rpm<V1≤200 rpm, V2 is 55 rpm≤V2≤100 rpm or 0 rpm.

[0022] The present invention also provides a zeolite self-supporting micro-nano reactor, which is prepared by any of the above synthesis methods of the zeolite self-supporting micro-nano reactor.

[0023] The present invention also provides the application of the zeolite self-supporting micro-nano reactor as a catalyst or catalyst carrier, and the application range includes alkylation, (ep) oxidation, isomerization and other reactions.

[0024] The present invention can prepare a zeolite self-supporting micro-nano reactor by controlling the zeolite synthesis process, i.e. adopting segmented variable speed dynamic synthesis, i.e. micron-sized crystal particles composed of highly interlaced zeolite sheets, which have the characteristics of high external specific surface area, high active site content, high active site accessibility, high chemical stability, high structural stability, etc., and can be directly used as a catalyst or as a catalyst carrier. This synthesis method has the advantages of simple steps, easy operation, high repeatability, low cost, green environmental protection, etc.

[0025] The speed and time of the reactor in each stage are very critical in the present invention.

[0026] Step 1: During the process of pre-treating gel 1 to prepare gel 2, the speed of the reactor must be controlled within the range of 10 to 50 rpm (low speed), and the pre-treatment time must be controlled within the range of 6 to 48 hours. If it exceeds the above range, it is not conducive to the formation of the zeolite self-supporting micro-nano reactor. At the same time, the speed of the reactor and the pre-treatment time have a certain corresponding relationship, that is, when the speed of the reactor is relatively high, the pre-treatment time is relatively short; when the speed of the reactor is relatively low, the pre-treatment time is relatively long.

[0027] Step 2: During the stepwise variable speed crystallization of gel 2, the speed of the reactor in the previous stage must be higher than that in the pretreatment process, that is, it must be controlled within the range of 55 to 200 rpm (medium and high speed), with the speed value range [50, 100] as medium speed and (100, 200] as high speed. At the same time, there is a certain corresponding relationship between the speed of the reactor in the previous stage and the speed of the reactor in the next stage during the crystallization process: when the speed V1 of the reactor in the previous stage is medium speed [50, 100], the speed V2 of the reactor in the next stage must be increased to high speed (100, 200] or maintained at medium speed [50, 100]; when the speed V1 of the reactor in the previous stage is high speed (100, 200], the speed of the reactor in the next stage must be reduced to [50, 100] or adjusted to static, and static means the speed is 0.

[0028] Step 2: During the stepwise variable speed crystallization of gel 2, if the total crystallization time is too short, it is not conducive to the formation of the zeolite self-supporting micro-nanoreactor. At the same time, the crystallization time of the previous stage and the crystallization time of the next stage have a certain corresponding relationship: when the crystallization time of the previous stage is relatively short, the crystallization time of the next stage needs to be relatively long; when the crystallization time of the previous stage is relatively long, the crystallization time of the next stage needs to be relatively short.

[0029] The beneficial effects of the present invention are:

[0030] The present invention adopts a segmented synthesis process of "low speed-medium speed-medium speed", "low speed-medium speed-high speed", "low speed-high speed-medium speed" or "low speed-high speed-static" to prepare a self-supporting micro-nano reactor. The principle is: pre-treating the gel under low speed conditions to form crystal seeds with a certain orientation in the gel 2; crystallization is carried out under medium speed, medium speed-high speed, high speed-medium speed or high speed-static conditions to grow zeolite sheets into highly interlaced and symbiotic micron-sized crystal particles, which have the characteristics of high external specific surface area, high active site content, high active site accessibility, high chemical stability, high structural stability, etc., that is, a zeolite self-supporting micro-nano reactor.

[0031] The zeolite self-supporting micro-nano reactor provided by the invention has simple preparation process, low cost, is easy to realize large-scale production, has excellent catalytic performance, and the catalytic pinene isomerization yield is as high as 98.3%. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a morphology diagram of the zeolite self-supporting micro-nanoreactor obtained in Example 1.

[0033] Figure 2 This is the morphology of the zeolite self-supporting micro-nanoreactor obtained in Example 7. DETAILED DESCRIPTION

[0034] The present invention is further described in detail in the following specific examples (the organic silicon source and inorganic silicon source in the following examples are all calculated as SiO2, the metal source is calculated as metal M, the inorganic salt is calculated as the contained sodium, potassium or ammonium radical, and the aluminum source is calculated as Al2O3). The drugs used in the examples are all commercially available products unless otherwise specified, and the methods used are all conventional methods in the art unless otherwise specified.

[0035] Example 1

[0036] This embodiment provides a method for preparing a self-supporting micro-nano reactor, which is carried out according to the following steps:

[0037] Step 1: 4.62 g of fumed silica (inorganic silicon source), 1.02 g of alumina (aluminum source), 1.09 g of sodium hydroxide (inorganic salt), 9.27 g of tetraethylammonium hydroxide (template) and 116 ml of deionized water were stirred and mixed at room temperature to form gel 1. In this embodiment, the molar ratio of each substance is aluminum source: inorganic silicon source: inorganic salt: template: water = 1:7.7:2.73:6.3:644; the obtained gel 1 was transferred to a polytetrafluoroethylene-lined stainless steel reactor, and rotated at 60°C at a rotation rate of 20 rpm around the horizontal axis for 12 hours (first stage rotation) to obtain gel 2.

[0038] Step 2: Adjust the temperature to 180°C, adjust the speed to 60 rpm for crystallization for 72 hours (second stage rotation), and then adjust the speed to 90 rpm for crystallization for 72 hours (third stage rotation) to allow the reaction gel to undergo dynamic hydrothermal crystallization. The total crystallization time is 6.5 days. Filter by suction or centrifugation, and dry at 105°C for 12 hours to obtain the molecular sieve raw powder (crude product).

[0039] Step three, subjecting the molecular sieve raw powder obtained in step two to acid treatment, the acid treatment specifically being as follows: firstly mixing the molecular sieve raw powder with 2 mol / L hydrochloric acid at a weight ratio of 1:40, refluxing at a temperature of 80°C for 15 hours, filtering, washing, and drying to obtain an acid-treated product, and then calcining the acid-treated product at a temperature of 550°C for 6 hours to obtain a self-supporting micro-nano reactor.

[0040] Example 2

[0041] The difference between this embodiment and the first embodiment is that the second speed in step 2 is set to 90 rpm. The rest is the same as the first embodiment.

[0042] Example 3

[0043] The difference between this embodiment and the first embodiment is that the third stage speed in step 2 is set to rotate at a rotation rate of 120 rpm. The rest is the same as the first embodiment.

[0044] Example 4

[0045] The difference between this embodiment and embodiment 1 is that in step 2, the second speed is set to 120 rpm and the third speed is set to 60 rpm. The rest is the same as embodiment 1.

[0046] Example 5

[0047] The difference between this embodiment and embodiment 1 is that in step 2, the second speed is set to 120 rpm and the third speed is set to 0 rpm. The rest is the same as embodiment 1.

[0048] Example 6

[0049] The difference between this embodiment and embodiment 1 is that in step 2, the second speed is set to 90 rpm and the third speed is set to 200 rpm. The rest is the same as embodiment 1.

[0050] Example 7

[0051] This embodiment provides a method for preparing a self-supporting micro-nano reactor, which is carried out according to the following steps:

[0052] Step 1, 4.62g of fumed silica (inorganic silicon source), 1.02g of alumina (aluminum source), 1.09g of sodium hydroxide (inorganic salt), 1.05g of zirconium nitrate (metal source), 9.27g of tetraethylammonium hydroxide (template) and 116ml of deionized water were stirred and mixed at room temperature to form a gel. In this embodiment, the molar ratio of each substance is aluminum source: inorganic silicon source: metal salt: inorganic salt: template: water = 1:7.7:0.31:2.73:6.3:644; the obtained gel 1 was transferred to a polytetrafluoroethylene-lined stainless steel reactor, and rotated at 60°C and 30 rpm around the horizontal axis for 12 hours (first stage rotation) to obtain gel 2;

[0053] Step 2: Adjust the temperature to 180°C, adjust the speed to 120 rpm for crystallization for 72 hours (second stage rotation), and then adjust the speed to 60 rpm for crystallization for 72 hours (third stage rotation) to allow the reaction gel to undergo dynamic hydrothermal crystallization. The total crystallization time is 6.5 days. Filter by suction or centrifugation, and dry at 105°C for 12 hours to obtain the molecular sieve raw powder (crude product).

[0054] Step 3: calcine the molecular sieve powder obtained in step 2 at 550° C. for 10 hours to obtain a self-supporting micro-nano reactor.

[0055] Example 8

[0056] The difference between this embodiment and embodiment 7 is that the first rotation time in step 1 is 24 hours, the total crystallization time is 7 days, and the rest is the same as embodiment 7.

[0057] Example 9

[0058] The difference between this embodiment and embodiment 7 is that the first rotation time in step 1 is 36 hours, the total crystallization time is 7.5 days, and the rest is the same as embodiment 7.

[0059] Example 10

[0060] The difference between this embodiment and embodiment 7 is that the first treatment time in step 1 is 48 hours, the total crystallization time is 8 days, and the rest is the same as embodiment 7.

[0061] Embodiment 11

[0062] This embodiment provides a method for preparing a self-supporting micro-nano reactor, which is carried out according to the following steps:

[0063] Step 1: 6.37 g of fumed silica (inorganic silicon source), 1.02 g of alumina (aluminum source), 0.88 g of sodium hydroxide (inorganic salt), 1.28 g of nickel nitrate (metal source), 9.27 g of tetraethylammonium hydroxide (template) and 116 ml of deionized water are stirred and mixed at room temperature to form a gel. In this embodiment, the molar ratio of each substance is aluminum source: inorganic silicon source: metal source: inorganic salt: template: water = 1:10.6:0.70:2.2:6.3:644; the obtained gel 1 is transferred to a polytetrafluoroethylene-lined stainless steel reactor, and rotated around a horizontal axis at a rotation rate of 30 rpm at 60°C for 12 hours (first stage rotation) to obtain gel 2.

[0064] Step 2: Adjust the temperature to 180°C, adjust the speed to 60 rpm for crystallization for 72 hours (second stage rotation), and then adjust the speed to 90 rpm for crystallization for 72 hours (third stage rotation) to allow the reaction gel to undergo dynamic hydrothermal crystallization. The total crystallization time is 6.5 days. Filter by suction or centrifugation, and dry at 105°C for 12 hours to obtain the molecular sieve raw powder (crude product).

[0065] Step three, subjecting the molecular sieve raw powder obtained in step two to acid treatment, the acid treatment specifically being: firstly mixing the molecular sieve raw powder with 2 mol / L hydrochloric acid at a weight ratio of 1:40, refluxing at a temperature of 80°C for 15 hours, filtering, washing and drying to obtain a self-supporting micro-nano reactor.

[0066] Example 12

[0067] The difference between this embodiment and embodiment 11 is that the second stage treatment temperature in step 2 is 200° C. The rest is the same as embodiment 11.

[0068] Embodiment 13

[0069] The difference between this embodiment and embodiment 11 is that the first stage processing temperature in step 1 is 90° C., and the rest is the same as embodiment 11.

[0070] Embodiment 14

[0071] The difference between this embodiment and embodiment 11 is that the first stage processing temperature in step 1 is 120° C., and the rest is the same as embodiment 11.

[0072] Embodiment 15

[0073] This embodiment provides a method for preparing a self-supporting micro-nano reactor, which is carried out according to the following steps:

[0074] Step 1: 6.37 g of fumed silica (inorganic silicon source), 1.02 g of alumina (aluminum source), 0.88 g of sodium hydroxide (inorganic salt), 0.41 g of tetrabutyl titanate (metal source), 9.27 g of tetraethylammonium hydroxide (template) and 116 ml of deionized water were stirred and mixed at room temperature to form a gel. In this embodiment, the molar ratio of each substance is aluminum source: inorganic silicon source: metal salt: sodium source: template: water = 1:10.6:0.12:2.2:6.3:644; the obtained gel 1 was transferred to a polytetrafluoroethylene-lined stainless steel reactor, and rotated around a horizontal axis at a rotation rate of 30 rpm at 120°C for 12 hours (first stage rotation) to obtain gel 2;

[0075] Step 2: Adjust the temperature to 180°C, adjust the speed to 60 rpm for crystallization for 72 hours (second stage rotation), adjust the speed to 90 rpm for crystallization for 72 hours (third stage rotation), and subject the reaction gel to dynamic hydrothermal crystallization. The total crystallization time is 6.5 days. Filter by suction or centrifugation, and dry at 105°C for 12 hours to obtain the molecular sieve raw powder (crude product).

[0076] Step 3: calcine the molecular sieve powder obtained in step 2 at 550° C. for 6 hours to obtain a self-supporting micro-nano reactor.

[0077] Example 16

[0078] The difference between this embodiment and embodiment 15 is that the third stage speed in step 2 is set to rotate at a rotation rate of 160 rpm, and the rest is the same as embodiment 15.

[0079] Embodiment 17

[0080] This embodiment provides a method for preparing a self-supporting micro-nano reactor, which is carried out according to the following steps:

[0081] Step 1: 6.37 g of fumed silica (inorganic silicon source), 1.02 g of alumina (aluminum source), 0.88 g of sodium hydroxide (inorganic salt), 0.42 g of iridium trichloride (metal source), 9.27 g of tetraethylammonium hydroxide (template) and 116 ml of deionized water were stirred and mixed at room temperature to form a gel. In this embodiment, the molar ratio of each substance is aluminum source: inorganic silicon source: metal salt: sodium source: template: water = 1:10.6:0.14:2.2:6.3:644; the obtained gel 1 was transferred to a polytetrafluoroethylene-lined stainless steel reactor, and rotated around a horizontal axis at a rotation rate of 30 rpm at 120°C for 12 hours (first stage rotation) to obtain gel 2;

[0082] Step 2: Adjust the temperature to 180°C, adjust the speed to 60 rpm for crystallization for 72 hours (second stage rotation), adjust the speed to 90 rpm for crystallization for 72 hours (third stage rotation), and subject the reaction gel to dynamic hydrothermal crystallization. The total crystallization time is 6.5 days. Filter by suction or centrifugation, and dry at 105°C for 12 hours to obtain the molecular sieve raw powder (crude product).

[0083] Step 3: calcine the molecular sieve powder obtained in step 2 at 550° C. for 6 hours to obtain a self-supporting micro-nano reactor.

[0084] Embodiment 18

[0085] The difference between this embodiment and Embodiment 17 is that the third stage speed of step 2 is set to a rotation rate of 200 rpm, and the rest is the same as Embodiment 17.

[0086] Performance Testing

[0087] from Figures 1-2 It can be seen that the self-supporting micro-nano reactor prepared in the present invention is micron crystal particles composed of highly interlaced and intergrown zeolite platelets.

[0088] Preparation of comparative catalyst: According to the preparation method of Example 1, only the second and third speeds in step 2 were changed to 30 rpm, and crystallization was carried out at 180°C for 6.5 days to prepare the catalyst.

[0089] The morphology of the zeolite self-supporting micro-nano reactor obtained in Example 1 is as follows Figure 1 As shown, Example 1-5 was directly used as a catalyst in the catalytic decalinization reaction to synthesize 2,6-dialkylnaphthalene (reaction conditions: 2.0 mmol naphthalene, 6.0 mmol tert-butanol, 150.0 mmol cyclohexane, 200 mg catalyst, reaction temperature 200° C., reaction time 6 hours).

[0090] The zeolite self-supporting micro-nanoreactor obtained in Example 6 was directly loaded with phosphotungstic acid (reaction conditions: 0.02 g phosphotungstic acid, 0.2 g catalyst, 20 ml H2O, reaction temperature 80°C, reaction time 6 hours) and the reaction results are shown in Table 1.

[0091] Table 1 Catalytic denaphthalene alkylation synthesis of 2,6-dialkylnaphthalene yield

[0092]

[0093] In Table 1 above, it can be seen from the data in Table 1 that only by changing the rotation speed during crystallization, the yield in the catalytic decalinization reaction to synthesize 2,6-dialkylnaphthalene is effectively improved. Therefore, the zeolite self-supporting micro-nano reactor prepared in the present invention has the advantage of high structural stability.

[0094] Example 7 The morphology of the zeolite self-supporting micro-nano reactor is as follows Figure 2 As shown, Examples 7 to 12 were directly used as catalysts in the catalytic epoxidation of allyl chloride (reaction conditions: 5.0 ml acetonitrile, 15.0 mmol allyl chloride, 3.0 ml acetonitrile H2O2, 100 mg catalyst, reaction temperature 60°C, reaction time 6 hours), and the reaction results are shown in Table 2.

[0095] Table 2 Catalytic epoxidation yield of allyl chloride

[0096] catalyst Catalytic epoxidation yield of allyl chloride (%) Example 7 96.5 Example 8 96.8 Example 9 97.5 Example 10 98.9 Embodiment 11 94.5 Example 12 91.3 Comparison of catalysts 68.6

[0097] In Table 2 above, it can be seen from the data in Table 2 that only by changing the rotation speed during crystallization, the yield in the catalytic epoxidation of allyl chloride is effectively improved. Therefore, the zeolite self-supporting micro-nano reactor prepared in the present invention has the advantage of high chemical stability.

[0098] The zeolite self-supporting micro-nanoreactor obtained in Examples 13 to 18 was applied to the catalytic isomerization reaction of pinene (reaction conditions: 2.0 mmol β-pinene, 4.0 mmol polyformaldehyde, 10 ml toluene, 100 mg catalyst, reaction temperature 60°C, reaction time 6 hours). The reaction results are shown in Table 3.

[0099] Table 3 Catalytic pinene isomerization yield

[0100] catalyst Catalytic pinene isomerization yield (%) Embodiment 13 97.1 Embodiment 14 98.3 Embodiment 15 96.2 Example 16 91.3 Embodiment 17 96.2 Embodiment 18 96.7 Comparison of catalysts 66.6

[0101] In Table 3 above, it can be seen from the data in Table 3 that only the rotation speed during crystallization is changed, and the yield of the embodiment in the catalytic pinene isomerization reaction is effectively improved. Therefore, the zeolite self-supporting micro-nano reactor prepared by the present invention has the advantage of high active site content.

[0102] The external specific surface area of ​​the zeolite self-supporting micro-nano reactor obtained in Example 7 was tested, and the result was 361.5 m 2 g -1 It can be seen that the zeolite self-supporting micro-nano reactor prepared by the present invention has the advantage of high external specific surface area.

Claims

1. A method for synthesizing a zeolite self-supporting micro-nanoreactor, characterized in that: The following steps are involved: Step 1: Aluminum source, silicon source, metal source, inorganic salt, organic template and deionized water are stirred and mixed at room temperature to form gel 1, gel 1 is transferred to a reaction kettle that can rotate around a horizontal axis and sealed, and treated at a temperature of 30 to 130° C. and a rotation speed of 10 to 50 rpm for 6 to 48 hours to obtain gel 2; Step 2, crystallizing the gel 2 at a temperature of 140-250° C. in a stepwise variable speed crystallization manner, wherein the stepwise variable speed crystallization comprises first crystallizing at a rotation speed of 55-200 rpm for 24-240 hours, then crystallizing at a rotation speed of 0-200 rpm for 24-120 hours, filtering, and drying to obtain a crude product; Step 3: Treat the crude product with acid, or first treat it with acid and then calcine it, or directly calcine it to obtain a zeolite self-supporting micro-nano reactor.

2. The method for synthesizing the zeolite self-supporting micro-nanoreactor according to claim 1, characterized in that: In step 1, the aluminum source is one or more of sodium aluminate, aluminum isopropoxide, aluminum oxide, aluminum chloride, aluminum hydroxide, pseudo-boehmite, and boehmite; The silicon source is an inorganic silicon source and / or an organic silicon source, wherein the inorganic silicon source is one or more of fumed silica, silica sol, ethyl orthosilicate, water glass, and silicon tetrachloride, and the organic silicon source is one or more of dimethyldiethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, mercaptopropyltriethoxysilane, aminopropyltriethoxysilane, hexadecyltriethoxysilane, and bis(triethoxysilyl)methane; The inorganic salt is one or more of sodium salt, potassium salt and ammonium salt. The sodium salt is one or more of sodium hydroxide, sodium aluminate, sodium chloride, sodium carbonate, sodium nitrate, sodium sulfate and sodium sulfite. The potassium salt is one or more of potassium chloride and potassium hydroxide. The ammonium salt is one or more of ammonium chloride, ammonium nitrate and ammonium fluoride.

3. The method for synthesizing the zeolite self-supporting micro-nano reactor according to claim 1, characterized in that: In step 1, the metal source is one or more of tin tetrachloride, dimethyltin dichloride, zirconium chloride, zirconium nitrate, nickel nitrate, zinc acetate, zinc chloride, ammonium metavanadate, iridium trichloride, n-butyl titanate, ferric chloride, ferric nitrate, manganese acetate, manganese chloride, cobalt acetate, cobalt chloride, cobalt nitrate, copper sulfate, and chromium nitrate; The organic template is one or more of piperidine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, cyclohexylamine, ethylene glycol, polyethylene glycol, isopropanol, tetrahydrofuran, cyclohexane, pyrrolidine, isopropylamine, hexamethyleneimine, ethylenediamine, dibutylamine, n-butylamine, 1,8-diaminooctane, N,N-diethyl cis-2,6-dimethylpiperidine, 1,3-dimethylimidazole, diethylenetriamine, and tetraethylenepentamine.

4. The method for synthesizing the zeolite self-supporting micro-nanoreactor according to claim 2, characterized in that: In step 1, the molar ratio of each reaction raw material is aluminum source: inorganic silicon source: organic silicon source: metal source: inorganic salt: organic template: deionized water = 1: (5-50): (0-10): (0-1): (0.1-5): (4-10): (60-900), wherein: the aluminum source is calculated as Al2O3, the inorganic silicon source and the organic silicon source are both calculated as SiO2, the metal source is calculated as metal M, and the inorganic salt is calculated as sodium, potassium or ammonium.

5. The method for synthesizing the zeolite self-supporting micro-nano reactor according to claim 1, characterized in that: In step 2, filtering is performed by suction filtration or centrifugation, and the drying is performed at 80 to 105° C. for 12 to 24 hours.

6. The method for synthesizing the zeolite self-supporting micro-nano reactor according to claim 1, characterized in that: In step three, the acid treatment includes mixing the crude product with 2-4 mol / L hydrochloric acid in a weight ratio of 1:40-60, refluxing at a temperature of 60-80° C. for 15-20 hours, and then filtering, washing, and drying; the calcination includes calcining at 550-600° C. for 4-10 hours.

7. The method for synthesizing the zeolite self-supporting micro-nanoreactor according to claim 1, characterized in that: In step 1, the gel 2 is prepared by treating the mixture at a temperature of 60 to 120° C. and a rotation speed of 20 to 30 rpm for 12 to 48 hours.

8. The method for synthesizing the zeolite self-supporting micro-nanoreactor according to claim 1, characterized in that: In step 2, the gel 2 is crystallized at a temperature of 180-200° C. in a stepwise variable speed crystallization, wherein the stepwise variable speed crystallization includes crystallizing at a rotation speed of V1 for 72-120 hours and then crystallizing at a rotation speed of V2 for 72-120 hours, wherein V1 and V2 satisfy the following relationship: When V1 is 55 rpm ≤ V1 ≤ 100 rpm, V2 is 55 rpm ≤ V2 ≤ 200 rpm; When the value of V1 is 100 rpm<V1≤200 rpm, V2 is 55 rpm≤V2≤100 rpm or 0 rpm.

9. A zeolite self-supporting micro-nano reactor, characterized in that: The zeolite self-supporting micro-nano reactor is prepared by the synthesis method of any one of claims 1 to 8.

10. An application of the zeolite self-supporting micro-nano reactor as claimed in claim 9, characterized in that: Application: catalyst or catalyst carrier.

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