Preparation method and application of template-agent-free high-crystallinity hierarchical-pore SAPO-15 zeolite molecular sieve
The synthesis of high-crystalline multi-stage pore SAPO-15 zeolite molecular sieve in high crystallinity is solved by the template-free method, and the problem of single pore structure of SAPO-15 zeolite molecular sieve in the prior art is solved, and the synthesis of multi-stage pore structure and high catalytic activity is achieved.
Patent Information
- Application Number
- CN202510296219.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-13
- Publication Date
- 2025-06-13
AI Technical Summary
The pore structure of the existing SAPO-15 zeolite molecular sieve is only microporous, making it difficult to deal with compounds with larger molecular structures and more complex compositions. At the same time, its synthesis relies on expensive organic small molecule template agents, which is unfriendly in the environment and may destroy the structure of SAPOs.
A high-crystalline multi-stage pore SAPO-15 zeolite molecular sieve was synthesized by a template-free method. By adding aluminum source, phosphorus source, silicon source, mineralizer and inorganic guide agent in sequence to water, stirring evenly, the crystallization reaction was carried out to obtain a multi-stage pore structure of SAPO-15 zeolite molecular sieve.
The multi-stage pore structure synthesis of SAPO-15 zeolite molecular sieve was achieved, which reduced the dependence on organic template agents, reduced the synthesis cost, and showed high catalytic activity and selectivity in the hydrogenation of carbon dioxide to methanol.
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of zeolite molecular sieves, and particularly to a preparation method and application of a template-free high-crystallinity hierarchical pore SAPO-15 zeolite molecular sieve. Background Art
[0002] Hierarchical pore zeolites have excellent acidity and hydrothermal stability of microporous zeolites as well as rich hierarchical pore structures, and have greatly improved the adsorption and diffusion properties of macromolecules based on those of microporous zeolites. Introducing mesoporous structures into microporous zeolites is beneficial to the diffusion of reactant molecules and enables the catalytic conversion of macromolecules, and is also conducive to exposing more surface active sites and increasing the active specific surface area. Therefore, as a new type of hierarchical pore material, it is quite popular in the fields of catalysis and adsorption and has great industrial application prospects.
[0003] Silicoaluminophosphate (SAPO) molecular sieves, as an important class of inorganic open-framework crystal materials, are composed of phosphorus-oxygen tetrahedra and aluminum-oxygen tetrahedra connected to each other through common oxygen vertices, and have regular pore channels or cage-like structures. As a new type of silicoaluminophosphate zeolite molecular sieve, the framework of SAPO-15 is also composed of silicon-oxygen tetrahedra, aluminum-oxygen tetrahedra and phosphorus-oxygen tetrahedra connected by oxygen bridges, and has a multi-dimensional pore channel structure composed of four-membered rings and six-membered rings, and the surface is acidic, which can be well used as a catalyst, an ion exchanger, and an adsorbent for separating and purifying molecules, and thus has received wide attention in the fields of industrial catalysis, adsorption separation and ion exchange. However, in the current research reports, the pore size of the obtained SAPO-15 zeolite molecular sieve is only 3.8 nm, and it is difficult to process compounds with larger molecular structures and more complex compositions. At the same time, the synthesis of SAPO-15 zeolite molecular sieves requires the use of expensive organic small molecule template agents, which are not only environmentally unfriendly but also can damage the structure of SAPOs during high-temperature calcination.
[0004] Therefore, the present invention improves the carrier performance by synthesizing a template-free high-crystallinity hierarchical pore SAPO-15 zeolite molecular sieve, which not only effectively solves the problems of contact and diffusion limitations of active sites, but also reduces the synthesis cost and realizes green chemistry. At the same time, it shows high catalytic activity and selectivity in the reaction of hydrogenation of carbon dioxide to methanol. Summary of the Invention
[0005] Aiming at the technical problems that the SAPO-15 zeolite molecular sieve has a microporous structure and does not have a hierarchical pore structure and the synthesis process depends on a template agent, the present invention provides a preparation method and application of a template-free high-crystallinity hierarchical pore SAPO-15 zeolite molecular sieve. The SAPO-15 zeolite molecular sieve synthesized by the method of the present invention has a hierarchical pore structure, and when used as a carrier to load transition metals to prepare a catalyst for use in the reaction of hydrogenation of carbon dioxide to methanol, it shows high catalytic activity and selectivity.
[0006] To achieve the above object, the present invention is realized through the following technical solutions:
[0007] A method for preparing a template-free highly crystalline hierarchical pore SAPO-15 zeolite molecular sieve, comprising the following steps:
[0008] (1) Sequentially add an aluminum source, a phosphorus source, a silicon source, a mineralizing agent, and an inorganic directing agent into water, and stir evenly after adding each raw material before adding other raw materials;
[0009] (2) Continue stirring for several hours after adding all the raw materials;
[0010] (3) Carry out a crystallization reaction on the mixture at 190 - 220 °C for 48 - 60 hours;
[0011] (4) After the crystallization reaction ends, carry out suction filtration and washing to obtain a hierarchical pore SAPO-15 zeolite molecular sieve;
[0012] Among them, the inorganic structure directing agent is an inorganic compound of an ammonium salt, and the mineralizing agent is represented by R;
[0013] The aluminum source is measured by Al 2 O 3 The phosphorus source is measured by P 2 O 5 The silicon source is measured by SiO 2 The inorganic structure directing agent is measured by NH 4 + The molar ratio of the feed amounts of each raw material is Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :NH 4 + :R = 1.0:41.3:0.87:(0.70 - 0.79):(0.75 - 1.3):4.2.
[0014] Preferably, the above aluminum source is aluminum isopropoxide.
[0015] Preferably, the above phosphorus source is an 85% wt phosphoric acid aqueous solution.
[0016] Preferably, the above silicon source is water glass.
[0017] Preferably, the above inorganic structure directing agent is ammonium chloride.
[0018] Preferably, the above mineralizing agent is ethylene glycol.
[0019] Preferably, the temperature of the crystallization reaction is 180 - 220 °C; the time of the crystallization reaction is 24 - 72 h.
[0020] Further, the temperature of the crystallization reaction is 190 - 200 °C; the time of the crystallization reaction is 48 - 60 h.
[0021] Further, the time of the continued stirring is 24 h; after the crystallization reaction, the operations of washing the product with water and drying are further included.
[0022] The present invention also provides an application of a template-free prepared highly crystalline hierarchical pore SAPO-15 zeolite molecular sieve in the reaction of hydrogenating carbon oxides to prepare alcohol compounds. The hierarchical pore SAPO-15 zeolite molecular sieve is loaded with a transition metal or a transition metal oxide and used as a catalyst.
[0023] Preferably, the above-mentioned transition metal is one or more of Zr, Ni, Co, Zn, Cu, and Fe.
[0024] Preferably, the above-mentioned transition metal is a Cu-containing metal or a Cu-containing metal oxide.
[0025] In addition, the present invention also provides a template-free prepared highly crystalline hierarchical pore SAPO-15 zeolite molecular sieve, which is obtained by the above preparation method.
[0026] In addition, the present invention also provides a catalyst, which comprises the above-mentioned hierarchical pore SAPO-15 zeolite molecular sieve and a transition metal or a transition metal oxide.
[0027] Preferably, the above-mentioned transition metal is one or more of Zr, Ni, Co, Zn, Cu, and Fe.
[0028] Preferably, the above-mentioned transition metal is a Cu-containing metal or a Cu-containing metal oxide.
[0029] Beneficial technical effects:
[0030] The present invention provides a preparation method of a template-free highly crystalline hierarchical pore SAPO-15 zeolite molecular sieve for synthesizing SAPO-15 zeolite. By using sodium silicate as a silicon source and aluminum isopropoxide as an aluminum source, and changing the reaction time and temperature, a highly crystalline hierarchical pore SAPO-15 zeolite molecular sieve can be obtained. Compared with the prior art, the dependence on a large amount of small molecule organic template agents in the traditional synthesis method is greatly reduced, and an environmentally friendly and low-cost synthesis route is found. Moreover, after the obtained highly crystalline hierarchical pore SAPO-15 zeolite molecular sieve is loaded with a transition metal as a catalyst carrier in the reaction of hydrogenating carbon dioxide to methanol, it can effectively catalyze the conversion of carbon dioxide to methanol. Description of the Drawings
[0031] Figure 1 XRD patterns of SAPO-15 zeolite molecular sieves synthesized from different silicon sources; among which, Example 1 uses tetraethyl orthosilicate, Example 2 uses sodium silicate, and Example 3 uses fumed silica gel.
[0032] Figure 2 XRD patterns of SAPO-15 zeolite molecular sieves synthesized with different silicon-aluminum ratios; among which, Example 4 has Al 2 O 3 :SiO 2 =1:0.70, Example 5 has Al 2 O 3 :SiO 2 =1:0.72, Example 6 has Al 2 O 3 :SiO 2 =1:0.74, Example 7 has Al 2 O 3 :SiO 2 =1:0.76, Example 8 has Al 2 O 3 :SiO 2 =1:0.78.
[0033] Figure 3 XRD patterns of SAPO-15 zeolite molecular sieves synthesized from different ammonium salts; among which, Example 9 uses ammonium chloride, Example 10 uses ammonium oxalate, and Example 11 uses ammonia water.
[0034] Figure 4 XRD patterns of SAPO-15 zeolite molecular sieves synthesized at different crystallization reaction temperatures; among which, Example 12 is at 180 °C, Example 13 is at 190 °C, Example 14 is at 200 °C, Example 15 is at 210 °C, and Example 16 is at 220 °C.
[0035] Figure 5 XRD patterns of SAPO-15 zeolite molecular sieves synthesized at different crystallization reaction times; among which, Example 17 is 24 h, Example 18 is 36 h, Example 19 is 48 h, Example 20 is 60 h, and Example 21 is 72 h.
[0036] Figure 6 N 2 adsorption-desorption isotherm and pore size distribution curve of the highly crystalline hierarchical pore SAPO-15 zeolite molecular sieve prepared in Example 14.
[0037] Figure 7 Catalytic activity diagram of each catalyst for carbon dioxide conversion in Application Example 1. Detailed implementation manners
[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments and the accompanying drawings. Obviously, the described embodiments are only some, but not all, embodiments of the present invention. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0039] Unless otherwise specifically stated, the numerical values set forth in these embodiments do not limit the scope of the present invention. Technologies and methods known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies and methods should be regarded as part of the specification. In all examples shown and discussed herein, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.
[0040] Solution A used in the following examples: Dissolve 14.6 g of aluminum isopropoxide in 15.5 mL of H 2 O and add 18.3 g of ethylene glycol to obtain.
[0041] In the following embodiments, in the expression of "molar ratio of each material Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :NH 4 + :R": Al 2 O 3 refers to the aluminum source, and the number of moles of the aluminum source is the number of moles of aluminum element in aluminum isopropoxide; SiO 2 refers to the silicon source, and the number of moles of the silicon source is the number of moles of silicon element in tetraethyl orthosilicate or water glass or fumed silica; P 2 O 5 refers to the phosphorus source, and the number of moles of the phosphorus source is the number of moles of phosphorus element in phosphoric acid; NH 4 + refers to the inorganic guiding agent, and R is the mineralizing agent.
[0042] Example 1
[0043] Solution B: Dissolve 10.6 g of water glass in 5 mL of H 2 O to obtain.
[0044] Add 4.6 mL of phosphoric acid to Solution A, stir evenly, then add Solution B drop by drop, stir well, and after stirring for 1 h, add 4.5 g of ammonium chloride and 12 mL of H 2O, stir for another 24 h to obtain a mixture. Then put the obtained mixture into a high-pressure reactor and place it in an oven at 190 °C for hydrothermal crystallization reaction for 48 h. After the crystallization is completed, cool the synthesis kettle to room temperature. Filter and wash the obtained product, and dry it in an oven at 90 °C overnight to obtain the product SAPO-15 molecular sieve. The molar ratio of each material in the system is Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :NH 4 + :R = 1.0:41.3:0.87:0.96:0.75:4.2.
[0045] The crystallinity of the prepared SAPO-15 zeolite molecular sieve is shown in Table 1.
[0046] Example 2
[0047] Solution B: Obtained by dissolving 2.1 g of fumed silica in 5 mL of H 2 O.
[0048] Add 4.6 mL of phosphoric acid to Solution A, stir evenly, then add Solution B drop by drop, stir well, add 4.5 g of ammonium chloride and 12 mL of H 2 O after stirring for 1 h, stir for another 24 h to obtain a mixture. Then put the obtained mixture into a high-pressure reactor and place it in an oven at 190 °C for hydrothermal crystallization reaction for 48 h. After the crystallization is completed, cool the synthesis kettle to room temperature. Filter and wash the obtained product, and dry it in an oven at 90 °C overnight to obtain the product SAPO-15 molecular sieve. The molar ratio of each material in the system is Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :NH 4 + :R = 1.0:41.3:0.87:0.96:0.75:4.2.
[0049] The crystallinity of the prepared SAPO-15 zeolite molecular sieve is shown in Table 1.
[0050] Example 3
[0051] Solution B: Obtained by dissolving 6.5 g of tetraethyl orthosilicate in 5 mL of H 2 O.
[0052] Add 4.6 mL of phosphoric acid to Solution A. After stirring evenly, add Solution B drop by drop. Stir well. After stirring for 1 h, add 4.5 g of ammonium chloride and 12 mL of H 2 O, and then stir for another 24 h to obtain a mixture. Then put the obtained mixture into a high-pressure reaction kettle and place it in an oven at 190 °C for hydrothermal crystallization reaction for 48 h. After the crystallization is completed, cool the synthesis kettle to room temperature. Filter and wash the obtained product, and place it in an oven at 90 °C to dry overnight to obtain the product SAPO-15 molecular sieve. The molar ratio of each material in the system is Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :NH 4 + :R = 1.0:41.3:0.87:0.96:0.75:4.2.
[0053] The crystallinity of the prepared SAPO-15 zeolite molecular sieve is shown in Table 1.
[0054] Experimental Example 4
[0055] Solution B: Obtained by dissolving 9.8 g of water glass in 5 mL of H 2 O.
[0056] Add 4.6 mL of phosphoric acid to Solution A. After stirring evenly, add Solution B drop by drop. Stir well. After stirring for 1 h, add 4.5 g of ammonium chloride and 12 mL of H 2 O, and then stir for another 24 h to obtain a mixture. Then put the obtained mixture into a high-pressure reaction kettle and place it in an oven at 190 °C for hydrothermal crystallization reaction for 48 h. After the crystallization is completed, cool the synthesis kettle to room temperature. Filter and wash the obtained product, and place it in an oven at 90 °C to dry overnight to obtain the product SAPO-15 molecular sieve. The molar ratio of each material in the system is Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :NH 4 + :R = 1.0:41.3:0.87:0.70:0.75:4.2.
[0057] The crystallinity of the prepared SAPO-15 zeolite molecular sieve is shown in Table 1.
[0058] Experimental Example 5
[0059] Solution B: Obtained by dissolving 10 g of water glass in 5 mL of H 2 O.
[0060] Add 4.6 mL of phosphoric acid to solution A. After stirring evenly, add solution B drop by drop. Stir well. After stirring for 1 h, add 4.5 g of ammonium chloride and 12 mL of H 2 O, and then stir for another 24 h to obtain a mixture. Then put the obtained mixture into a high-pressure reactor and place it in an oven at 190 °C for hydrothermal crystallization reaction for 48 h. After the crystallization is completed, cool the synthesis kettle to room temperature. The obtained product is filtered and washed by suction, and placed in an oven at 90 °C to dry overnight to obtain the product SAPO-15 molecular sieve. The molar ratio of each material in the system is Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :NH 4 + :R = 1.0:41.3:0.87:0.72:0.75:4.2.
[0061] The crystallinity of the prepared SAPO-15 zeolite molecular sieve is shown in Table 1.
[0062] Experimental Example 6
[0063] Solution B: Obtained by dissolving 10.3 g of water glass in 5 mL of H 2 O.
[0064] Add 4.6 mL of phosphoric acid to solution A. After stirring evenly, add solution B drop by drop. Stir well. After stirring for 1 h, add 4.5 g of ammonium chloride and 12 mL of H 2 O, and then stir for another 24 h to obtain a mixture. Then put the obtained mixture into a high-pressure reactor and place it in an oven at 190 °C for hydrothermal crystallization reaction for 48 h. After the crystallization is completed, cool the synthesis kettle to room temperature. The obtained product is filtered and washed by suction, and placed in an oven at 90 °C to dry overnight to obtain the product SAPO-15 molecular sieve. The molar ratio of each material in the system is Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :NH 4 + :R = 1.0:41.3:0.87:0.74:0.75:4.2.
[0065] The crystallinity of the prepared SAPO-15 zeolite molecular sieve is shown in Table 1.
[0066] Experimental Example 7
[0067] Solution B: Obtained by dissolving 10.6 g of water glass in 5 mL of H 2Obtained from O.
[0068] Add 4.6 mL of phosphoric acid to Solution A. After stirring evenly, add Solution B drop by drop. Stir well. After stirring for 1 h, add 4.5 g of ammonium chloride and 12 mL of H 2 O, and stir for another 24 h to obtain a mixture. Then put the obtained mixture into a high-pressure reactor and place it in an oven at 190 °C for hydrothermal crystallization reaction for 48 h. After the crystallization is completed, cool the synthesis kettle to room temperature. The obtained product is filtered and washed by suction, and placed in an oven at 90 °C to dry overnight to obtain the product SAPO-15 molecular sieve. The molar ratio of each material in the system is Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :NH 4 + :R = 1.0:41.3:0.87:0.76:0.75:4.2.
[0069] The crystallinity of the prepared SAPO-15 zeolite molecular sieve is shown in Table 1.
[0070] Experimental Example 8
[0071] Solution B: Dissolve 10.9 g of water glass in 5 mL of H 2 O to obtain.
[0072] Add 4.6 mL of phosphoric acid to Solution A. After stirring evenly, add Solution B drop by drop. Stir well. After stirring for 1 h, add 4.5 g of ammonium chloride and 12 mL of H 2 O, and stir for another 24 h to obtain a mixture. Then put the obtained mixture into a high-pressure reactor and place it in an oven at 190 °C for hydrothermal crystallization reaction for 48 h. After the crystallization is completed, cool the synthesis kettle to room temperature. The obtained product is filtered and washed by suction, and placed in an oven at 90 °C to dry overnight to obtain the product SAPO-15 molecular sieve. The molar ratio of each material in the system is Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :NH 4 + :R = 1.0:41.3:0.87:0.78:0.75:4.2.
[0073] The crystallinity of the prepared SAPO-15 zeolite molecular sieve is shown in Table 1.
[0074] Experimental Example 9
[0075] Solution B: Dissolve 10.6 g of water glass in 5 mL of H2 Obtained from
[0076] Add 4.6 mL of phosphoric acid to Solution A. After stirring evenly, add Solution B drop by drop. Stir well. After stirring for 1 h, add 4.5 g of ammonium chloride and 12 mL of H 2 O, and stir for another 24 h to obtain a mixture. Then put the obtained mixture into a high-pressure reactor and place it in an oven at 190 °C for hydrothermal crystallization reaction for 48 h. After the crystallization is completed, cool the synthesis kettle to room temperature. The obtained product is filtered and washed by suction, and placed in an oven at 90 °C to dry overnight to obtain the product SAPO-15 molecular sieve. The molar ratio of each material fed in the system is Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :NH 4 + :R = 1.0:41.3:0.87:0.76:0.75:4.2.
[0077] The crystallinity of the prepared SAPO-15 zeolite molecular sieve is shown in Table 1.
[0078] Experimental Example 10
[0079] Solution B: Dissolve 10.6 g of water glass in 5 mL of H 2 O to obtain.
[0080] Add 4.6 mL of phosphoric acid to Solution A. After stirring evenly, add Solution B drop by drop. Stir well. After stirring for 1 h, add 3 g of ammonium oxalate and 12 mL of H 2 O, and stir for another 24 h to obtain a mixture. Then put the obtained mixture into a high-pressure reactor and place it in an oven at 190 °C for hydrothermal crystallization reaction for 48 h. After the crystallization is completed, cool the synthesis kettle to room temperature. The obtained product is filtered and washed by suction, and placed in an oven at 90 °C to dry overnight to obtain the product SAPO-15 molecular sieve. The molar ratio of each material fed in the system is Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :NH 4 + :R = 1.0:41.3:0.87:0.76:0.75:4.2.
[0081] The crystallinity of the prepared SAPO-15 zeolite molecular sieve is shown in Table 1.
[0082] Experimental Example 11
[0083] Solution B: Prepared by dissolving 10.6 g of water glass in 5 mL of H 2 O.
[0084] Add 4.6 mL of phosphoric acid to Solution A, stir evenly, and then add Solution B drop by drop. Stir well, and after stirring for 1 h, add 6.5 g of ammonia water and 12 mL of H 2 O, and stir for another 24 h to obtain a mixture. Then put the obtained mixture into a high-pressure reaction kettle and place it in an oven at 190 °C for hydrothermal crystallization reaction for 48 h. After the crystallization is completed, cool the synthesis kettle to room temperature. The obtained product is filtered and washed by suction, and placed in an oven at 90 °C to dry overnight to obtain the product SAPO-15 molecular sieve. The molar ratio of each material in the system is Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :NH 4 + :R = 1.0:41.3:0.87:0.76:0.75:4.2.
[0085] The crystallinity of the prepared SAPO-15 zeolite molecular sieve is shown in Table 1.
[0086] Experimental Examples 12 - 16
[0087] The preparation method of the products in Examples 12 - 16 is the same as that in Example 1, except that the crystallization reaction temperature is different.
[0088] The crystallization reaction temperature of Example 12 is 180 °C.
[0089] The crystallization reaction temperature of Example 13 is 190 °C (the same as Example 1).
[0090] The crystallization reaction temperature of Example 14 is 200 °C.
[0091] The crystallization reaction temperature of Example 15 is 210 °C.
[0092] The crystallization reaction temperature of Example 16 is 220 °C.
[0093] The crystallinity of the prepared SAPO-15 zeolite molecular sieve is shown in Table 1.
[0094] Examples 17 - 21
[0095] The preparation method of the products in Examples 17 - 21 is the same as that in Example 14, except that the crystallization reaction time is different.
[0096] The crystallization reaction time of Example 17 is 24 h.
[0097] The crystallization reaction time of Example 18 was 36 h.
[0098] The crystallization reaction time of Example 19 was 48 h (the same as Example 11).
[0099] The crystallization reaction time of Example 20 was 60 h.
[0100] The crystallization reaction time of Example 21 was 72 h.
[0101] The crystallinity of the prepared SAPO-15 zeolite molecular sieve is shown in Table 1.
[0102] Crystallinity calculation method: The crystallinity was tested using an X-ray diffractometer, and the calculation formula is: crystallinity = (diffraction peak intensity / total intensity) * 100%. Data processing was carried out using jade software. The reaction parameters and specific crystallinity data of the above examples are shown in Table 1.
[0103] Table 1 Reaction parameters and crystallinity of examples
[0104]
[0105] As can be seen from Table 1, the XRD patterns of the SAPO-15 zeolite molecular sieves synthesized under different silicon sources in Examples 1-3 are as Figure 1 shown. From Figure 1 and Figure 6 it can be seen that hierarchical pore SAPO-15 molecular sieve was obtained in Example 1.
[0106] In the above Examples 4-8, the XRD patterns synthesized under different Al 2 O 3 :SiO 2 ratios are as Figure 2 shown. From Figure 2 and Table 1, it can be seen that SAPO-15 has a crystallinity of more than 80%.
[0107] In Examples 13-16 and Examples 19-20, under the condition that the molar ratio of each raw material feed is Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :NH 4 + :R = 1.0:41.3:0.87:0.76:0.75:1.48, and crystallization reaction at 190-220 °C for 48-60 h, hierarchical pore SAPO-15 zeolite molecular sieve can be obtained, and the crystallinity of the SAPO-15 zeolite molecular sieve is above 80%. Among them, Example 14 is the best reaction condition.
[0108] N of the SAPO-15 zeolite molecular sieve of Example 14 2 The adsorption-desorption isotherm and pore size distribution curve diagram are as follows Figure 6 shown. It can be seen from Figure 6 that the method of the present invention has prepared a high-crystallinity hierarchical pore SAPO-15 zeolite molecular sieve.
[0109] Application Example 1
[0110] The above-mentioned high-crystallinity hierarchical pore SAPO-15 zeolite molecular sieve of Example 14 was applied to the reaction of hydrogenating carbon dioxide to methanol.
[0111] The hierarchical pore SAPO-15 zeolite molecular sieve was used as a carrier to load a transition metal to prepare a catalyst. The specific preparation process: Weigh a certain amount of aluminum isopropoxide and dissolve it in deionized water. After stirring evenly, add a certain amount of ethylene glycol, an 85% wt phosphoric acid solution, and water glass in sequence. After fully stirring evenly, add ammonium chloride. Carry out hydrothermal crystallization reaction at 200 °C for 48 h. The system composition is Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :NH 4 + :R = 1.0:41.3:0.87:(0.73 - 0.79):0.76:4.2. After filtering, washing, and drying the product obtained from the reaction, the SAPO-15 zeolite molecular sieve powder sample is obtained, and its water intake rate is measured to be 6. The corresponding catalyst is prepared by the incipient wetness impregnation method. Metal nitrates are selected as precursors, and the mass of the metal nitrates required is calculated according to 5% of the total mass of the catalyst, and the solution is prepared based on the measured water intake rate and evenly dropped onto the surface of the zeolite molecular sieve. Subsequently, it is dried in the air for 12 h, then dried at 100 °C for 12 h, and the required metal-loaded zeolite molecular sieve catalyst is obtained after calcination.
[0112] 5% Zr / SAPO-15, 5% Co / SAPO-15, 5% Zn / SAPO-15, 5% Cu / SAPO-15, 5% Ni / SAPO-15, 5% Fe / SAPO-15, 5% Zr-5% Cu / SAPO-15, 5% Co-5% Cu / SAPO-15, 5% Zn-5% Cu / SAPO-15, 5% Ni-5% Cu / SAPO-15, 5% Fe-5% Cu / SAPO-15 catalysts were prepared respectively according to the foregoing method, and the catalytic activities of the series of SAPO-15 zeolite molecular sieve catalysts for hydrogenating CO 2 to methanol are as follows Figure 7 shown. It can be seen from Figure 7It can be seen that the CO conversion rate on 5% Cu / SAPO-15 is the highest (19.83%), and the selectivity of the target product methanol is the best (88.87%). 2 As described above, this is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, should be covered by the protection scope of the present invention.
[0113] As described above, this is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, should be covered by the protection scope of the present invention.
Claims
1. A method for preparing a high-crystallinity multi-level porous SAPO-15 zeolite molecular sieve without a template agent, without using a small molecule template agent, characterized in that: The following steps are involved: (1) Add aluminum source, phosphorus source, silicon source, mineralizer, and inorganic directing agent to water in sequence, stir evenly after adding each raw material, and then add other raw materials; (2) After all the raw materials are added, continue stirring for several hours; (3) crystallizing the mixture at 190-220° C. for 48-60 hours; (4) After the crystallization reaction is completed, the multi-level pore SAPO-15 zeolite molecular sieve is obtained by filtration and washing; Wherein, the inorganic directing agent is an inorganic compound of ammonium salt, and R represents a mineralizer; The aluminum source is measured in Al2O3, the phosphorus source is measured in P2O5, the silicon source is measured in SiO2, and the inorganic structure directing agent is measured in NH4 + Metering, the molar ratio of each raw material is Al2O3:H2O:P2O5:SiO2:NH4 + :R=1.0:41.3:0.87:(0.70-0.79):(0.75-1.3):4.
2.
2. The method for preparing a high-crystallinity multi-level pore SAPO-15 zeolite molecular sieve according to claim 1, characterized in that: The aluminum source is aluminum isopropoxide.
3. The method for preparing the high crystallinity multi-level pore SAPO-15 zeolite molecular sieve according to claim 1, characterized in that: The phosphorus source is an 85% wt phosphoric acid aqueous solution.
4. The method for preparing the high crystallinity multi-level pore SAPO-15 zeolite molecular sieve according to claim 1, characterized in that: The silicon source is water glass.
5. The method for preparing the high crystallinity multi-level pore SAPO-15 zeolite molecular sieve according to claim 1, characterized in that: The inorganic structure directing agent is ammonium chloride.
6. The method for preparing the high crystallinity multi-level pore SAPO-15 zeolite molecular sieve according to claim 1, characterized in that: The mineralizer is ethylene glycol.
7. The method for preparing a high-crystallinity multi-level-pore SAPO-15 zeolite molecular sieve according to claim 1, characterized in that: After the crystallization reaction is completed, the product is washed with water and dried.
8. Application of a high-crystallinity multi-level pore SAPO-15 zeolite molecular sieve in the reaction of hydrogenating carbon oxides to prepare alcohol compounds, characterized in that: The high crystallinity multi-level pore SAPO-15 zeolite molecular sieve is loaded with transition metal or transition metal oxide to prepare a catalyst for use.
9. The use according to claim 8, characterized in that: The transition metal is one or more of Zr, Ni, Co, Zn, Cu, and Fe.
10. The use according to claim 8, characterized in that: The transition metal is a metal containing Cu or a metal oxide containing Cu.
11. A high crystallinity multi-level pore SAPO-15 zeolite molecular sieve, characterized in that: The method is obtained by the preparation method according to any one of claims 1 to 7.
12. A catalyst, characterized in that The method comprises the multi-level pore SAPO-15 zeolite molecular sieve according to claim 11 and a transition metal or a transition metal oxide.
13. The catalyst according to claim 12, characterized in that The transition metal is one or more of Zr, Ni, Co, Zn, Cu, and Fe.
14. The catalyst according to claim 12, characterized in that The transition metal is a metal containing Cu or a metal oxide containing Cu.