Preparation method and application of shape-controllable high-crystallinity SAPO-20 zeolite molecular sieve

Abstract

The invention relates to a preparation method and application of a morphology-controllable high-crystallinity SAPO-20 zeolite molecular sieve, and the preparation method comprises the following steps: sequentially adding an aluminum source, a phosphorus source, a silicon source and an organic amine structure-directing agent into water, continuously stirring for 12 hours after all the raw materials are added, carrying out hydrothermal crystallization reaction at 195-225 DEG C for 60-96 hours, filtering, washing, and drying to obtain the morphology-controllable high-crystallinity SAPO-20 zeolite molecular sieve. And taking out the product, washing with water until the pH value is neutral, drying, and calcining at 450 DEG C for 6 hours to obtain the SAPO-20 zeolite molecular sieves with different morphologies. Wherein the different silicon sources are one of magnesium trisilicate and tetraethyl silicate; the aluminum source is one of aluminum isopropoxide or pseudo-boehmite; the molar ratio of Al2O3 to H2O to P2O5 to SiO2 to the organic amine structure-directing agent is (0.9-1.2): 63: 1.8: 1.0: 1.6, and the molar ratio of Al2O3 to H2O to P2O5 to SiO2 to the organic amine structure-directing agent is (0.9-1.2): 63: 1.8: 1.0: 1.6. Different silicon sources and aluminum sources are simply regulated and controlled, so that the SAPO-20 molecular sieves which are high in crystallinity and have special morphologies such as a cubic shape, a nano-particle piled cake shape and a nano-particle piled spherical shape are prepared, and the SAPO-20 molecular sieves are applied to a reaction for preparing alcohol compounds through hydrogenation of oxycarbide.

Description

Technical Field

[0001] The present invention relates to the technical field of molecular sieve synthesis, and particularly relates to a preparation method and application of a highly crystalline SAPO-20 zeolite molecular sieve with controllable morphology. Background Art

[0002] Silicoaluminophosphate molecular sieves (abbreviated as SAPO molecular sieves) are three-dimensional crystal structures composed of AlO4, SiO4, and PO4 tetrahedra sharing oxygen atoms. In the pore channels within the crystal, Si 4+ partially replaces P 5+ or Al 3+ to generate acidity. Common silicoaluminophosphate zeolite molecular sieves include SAPO-11, SAPO-18, SAPO-31, SAPO-41, SAPO-56, etc. Others such as SAPO-20, SAPO-15, etc. are rarely reported. Among them, SAPO-20 silicoaluminophosphate zeolite molecular sieve is a kind of aluminophosphosilicate zeolite molecular sieve that is isostructural with AlPO-20 and sodalite (SOD), belonging to the cubic crystal system. Its regular cavity framework structure and high specific surface area endow it with good shape-selective adsorption and catalytic properties. The pentavalent P on the zeolite framework is easily replaced by tetravalent Si during the growth of the zeolite crystal, and then the formed silicon-oxygen tetrahedron carries a negative charge, having obvious electron-donating ability, thus serving as a good catalyst, ion exchanger, and adsorbent for separating and purifying molecules.

[0003] In current research reports, the pore size of the obtained SAPO-20 zeolite molecular sieve is only 0.4 nm, which is a microporous structure, and the morphology is a single square-shaped crystal grain. However, the dense square-shaped structure on the surface and the small pore diameter will cause drawbacks such as hindering the adsorption and diffusion of molecules during actual application, greatly limiting its industrial application. It should be noted that for zeolite molecular sieves, the morphology can not only affect their structural integrity, active specific surface area, and the distribution of active species, thereby changing their adsorption and catalytic efficiency, but also different morphologies are beneficial to exposing more surface active sites, which can promote the optimization of the diffusion paths of reactants and products in the zeolite pores, thus improving the selectivity and adsorption efficiency of specific reactions.

[0004] The design of the microstructure can change the macroscopic morphology of the catalyst, and then guide the regulation of the catalyst performance. Therefore, we propose a synthesis method of a highly crystalline SAPO-20 zeolite molecular sieve with controllable morphology by simply adjusting the synthesis raw materials, and explore the catalytic activity and selectivity of SAPO-20 with different morphologies in the reaction of hydrogenation of carbon oxides to alcohols. Summary of the Invention

[0005] Aiming at the problem of the single morphology of the current SAPO-20 zeolite molecular sieve, the present invention provides a preparation method and application of a SAPO-20 zeolite molecular sieve with controllable morphology and high crystallinity. The present invention can prepare SAPO-20 molecular sieves with high crystallinity and special morphologies of cubic type, nanoparticle-packed cake shape and nanoparticle-packed spherical shape by simply regulating different silicon sources and aluminum sources.

[0006] Specifically, the present invention is realized through the following technical solutions:

[0007] (1) Preparation method of high-crystallinity cubic SAPO-20 zeolite molecular sieve. The cubic SAPO-20 zeolite has a microporous structure with a pore size distribution of 2.95 nm, and the method includes the following steps:

[0008] Using pseudoboehmite as the aluminum source, 85 wt% phosphoric acid aqueous solution as the phosphorus source, and magnesium trisilicate as the silicon source, after mixing and stirring evenly in this order, N,N,N',N'-tetramethyl-1,6-hexanediamine is added, and then stirred for 12 h to obtain a mixture; then the obtained mixture is loaded into a high-pressure reaction kettle and subjected to hydrothermal crystallization reaction in the range of 195-225 °C, and the reaction time is between 60-96 h. After taking out the product, it is washed with water until neutral and dried, and then calcined at 450 °C for 6 h to obtain a high-crystallinity cubic SAPO-20 zeolite molecular sieve;

[0009] In an embodiment of the present invention, the aluminum source, the phosphorus source, the silicon source, and the organic amine template agent are calculated according to Al 2 O 3 , P 2 O 5 , SiO 2 , TMHD to calculate the raw material feeding amount, and the raw materials are added according to the molar ratio of Al 2 O 3 : H 2 O: P 2 O 5 : SiO 2 : TMHD = (0.9-1.2): 63: 1.8: 1.0: 1.6.

[0010] Furthermore, in the system, the aluminum source, the phosphorus source, the silicon source, and the organic amine template agent are calculated according to Al 2 O 3 , P 2 O 5 , SiO 2 , TMHD to calculate the raw material feeding amount, and the raw materials are added according to the molar ratio of Al 2 O 3 : H 2 O: P 2 O 5 : SiO2 : Add raw materials with a molar ratio of TMHD = 1.1:63:1.8:1.0:1.6.

[0011] Furthermore, the temperature of the hydrothermal crystallization reaction is 205 - 225 °C, and the time is 72 - 84 h.

[0012] In one embodiment of the present invention, the crystallization temperature is preferably 215 °C.

[0013] In one embodiment of the present invention, extending the crystallization time is beneficial to promoting complete crystallization. The most preferred crystallization time is 84 h, and a high-crystallinity cubic SAPO-20 zeolite molecular sieve can be obtained.

[0014] (2) Preparation method of high-crystallinity nanoparticle-packed cake-like SAPO-20 zeolite molecular sieve. The nanoparticle-packed cake-like SAPO-20 zeolite has a hierarchical pore structure with pore sizes distributed between 7.55 nm and 30.77 nm, and includes the following steps:

[0015] Using aluminum isopropoxide as the aluminum source, 85 wt% phosphoric acid aqueous solution as the phosphorus source, and magnesium trisilicate as the silicon source. After mixing and stirring evenly in this order, add N,N,N',N'-tetramethyl-1,6-hexanediamine, and then stir for 12 h to obtain a mixture; then put the obtained mixture into a high-pressure reaction kettle and carry out a hydrothermal crystallization reaction in the range of 195 - 225 °C for a reaction time between 60 - 96 h. After taking out the product, wash it with water until neutral and dry it, and calcine it at 450 °C for 6 h to obtain a high-crystallinity nanoparticle-packed cake-like SAPO-20 zeolite molecular sieve;

[0016] In one embodiment of the present invention, the aluminum source, the phosphorus source, the silicon source, and the organic amine template agent are calculated based on Al 2 O 3 , P 2 O 5 , SiO 2 to calculate the raw material feeding amount, and add raw materials according to the molar ratio of Al 2 O 3 : H 2 O: P 2 O 5 : SiO 2 : TMHD = (0.9 - 1.2):63:1.8:1.0:1.6.

[0017] Furthermore, in the system, the aluminum source, the phosphorus source, the silicon source, and the organic amine template agent are based on Al 2 O 3 , P 2 O 5 , SiO 2, Calculate the feeding amount of raw materials for TMHD, and add raw materials according to the molar ratio of Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :TMHD = 1.2:63:1.8:1.0:1.6. Further, the temperature of the hydrothermal crystallization reaction is 205 - 225 °C and the time is 72 - 84 h.

[0018] In one embodiment of the present invention, the crystallization temperature is preferably 215 °C.

[0019] In one embodiment of the present invention, prolonging the crystallization time is beneficial to promoting complete crystallization. The most preferred crystallization time is 84 h, and high-crystallinity nanoparticle-packed cake-like SAPO-20 zeolite molecular sieve can be obtained.

[0020] (3) Preparation method of high-crystallinity nanoparticle-packed spherical SAPO-20 zeolite molecular sieve. The nanoparticle-packed spherical SAPO-20 zeolite has a mesoporous structure with a pore size distribution of 31.27 nm, and includes the following steps:

[0021] Using aluminum isopropoxide as the aluminum source, 85 wt% phosphoric acid aqueous solution as the phosphorus source, and tetraethyl orthosilicate as the silicon source. After mixing and stirring evenly in this order, add N,N,N',N'-tetramethyl-1,6-hexanediamine, and then stir for 12 h to obtain a mixture; then load the obtained mixture into a high-pressure reaction kettle, place it in the range of 195 - 225 °C for hydrothermal crystallization reaction, the reaction time is between 60 - 96 h, wash the product with water until neutral after taking it out, dry it, and calcine it at 450 °C for 6 h to obtain high-crystallinity nanoparticle-packed spherical SAPO-20 zeolite molecular sieve;

[0022] In one embodiment of the present invention, the aluminum source, the phosphorus source, the silicon source, and the organic amine template agent are calculated for the feeding amount of raw materials according to Al 2 O 3 , P 2 O 5 , SiO 2 , TMHD, and add raw materials according to the molar ratio of Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :TMHD = (0.9 - 1.2):63:1.8:1.0:1.6.

[0023] Further, in the system, the aluminum source, the phosphorus source, the silicon source, and the organic amine template agent are calculated for the feeding amount of raw materials according to Al 2O 3 and P 2 O 5 and SiO 2 The TMHD calculates the raw material feeding amount. The raw materials are added according to the molar ratio of Al 2 O 3 : H 2 O: P 2 O 5 : SiO 2 : TMHD = 1.1:63:1.8:1.0:1.6.

[0024] Furthermore, the temperature of the hydrothermal crystallization reaction is 205 - 225 °C, and the time is 72 - 84 h.

[0025] In one embodiment of the present invention, the crystallization temperature is preferably 215 °C.

[0026] In one embodiment of the present invention, extending the crystallization time is beneficial to promoting complete crystallization. The most preferred crystallization time is 84 h, and high-crystallinity nanoparticle-packed cake-like SAPO-20 zeolite molecular sieves can be obtained.

[0027] Finally, the present invention also provides the application of the above-mentioned SAPO-20 zeolite molecular sieves with different morphologies as carriers loaded with transition metals to prepare Co-SAPO-20 molecular sieve catalysts in the reaction of hydrogenating carbon oxides to alcohols. The transition metal is a Co-containing metal or a Co-containing metal oxide.

[0028] Beneficial technical effects:

[0029] The present invention can prepare special-shaped SAPO-20 molecular sieves with high crystallinity and morphologies of cubic, nanoparticle-packed cake-like, and nanoparticle-packed spherical by simple regulation of different silicon sources and aluminum sources through traditional hydrothermal synthesis.

[0030] The high-crystallinity SAPO-20 zeolite molecular sieves with special morphologies of cubic, nanoparticle-packed cake-like, and nanoparticle-packed spherical synthesized by the method of the present invention not only effectively regulate the pore structure, morphology, and surface properties, but especially when used as a catalyst, when used as a carrier loaded with transition metals to prepare Co-SAPO-20 molecular sieve catalysts and applied to the reaction of hydrogenating carbon oxides to alcohol compounds, can effectively catalyze the conversion of carbon oxides to alcohols, not only greatly improving the conversion rate of carbon oxides, but also ensuring the yield of the target product. Description of the drawings

[0031] Figure 1 It is the SEM image of the high-crystallinity cubic SAPO-20 zeolite molecular sieve prepared in Example 27.

[0032] Figure 2 SEM image of the high-crystallinity nanoparticle-packed cake-like SAPO-20 zeolite molecular sieve prepared in Example 31.

[0033] Figure 3 SEM image of the high-crystallinity nanoparticle-packed spherical SAPO-20 zeolite molecular sieve prepared in Example 35.

[0034] Figure 4 N 2 adsorption-desorption isotherm and pore size distribution curve graphs of the high-crystallinity cubic SAPO-20, nanoparticle-packed cake-like SAPO-20, and nanoparticle-packed spherical SAPO-20 zeolite molecular sieves prepared in Example 27, Example 31, and Example 35.

[0035] Figure 5 For different Al 2 O 3 :P 2 O 5 XRD patterns of the cubic SAPO-20 zeolite molecular sieve synthesized at different Al 2 O 3 :P 2 O 5 = 0.9:1.8, Example 2 represents Al 2 O 3 :P 2 O 5 = 1.0:1.8, Example 3 represents Al 2 O 3 :P 2 O 5 = 1.1:1.8, Example 4 represents Al 2 O 3 :P 2 O 5 = 1.2:1.8.

[0036] Figure 6 For different Al 2 O 3 :P 2 O 5 XRD patterns of the nanoparticle-packed cake-like SAPO-20 zeolite molecular sieve synthesized at different Al 2 O 3 :P 2 O 5 = 0.9:1.8, Example 5 represents Al 2 O 3 :P 2 O 5 = 1.0:1.8, Example 7 represents Al 2 O3 :P 2 O 5 = 1.1:1.8. Example 8 represents Al 2 O 3 :P 2 O 5 = 1.2:1.8.

[0037] Figure 7 are XRD patterns of nanoparticle-packed spherical SAPO-20 zeolite molecular sieves synthesized at different Al 2 O 3 :P 2 O 5 :P ratios; where Example 9 represents Al 2 O 3 :P 2 O 5 = 0.9:1.8. Example 10 represents Al 2 O 3 :P 2 O 5 = 1.0:1.8. Example 11 represents Al 2 O 3 :P 2 O 5 = 1.1:1.8. Example 12 represents Al 2 O 3 :P 2 O 5 = 1.2:1.8.

[0038] Figure 8 are XRD patterns of cubic SAPO-20 zeolite molecular sieves synthesized at different crystallization reaction temperatures; where Example 13 represents 195 °C, Example 14 represents 205 °C, Example 15 represents 215 °C, and Example 16 represents 225 °C.

[0039] Figure 9 are XRD patterns of nanoparticle-packed cake-like SAPO-20 zeolite molecular sieves synthesized at different crystallization reaction temperatures; where Example 17 represents 195 °C, Example 18 represents 205 °C, Example 19 represents 215 °C, and Example 20 represents 225 °C.

[0040] Figure 10 are XRD patterns of nanoparticle-packed spherical SAPO-20 zeolite molecular sieves synthesized at different crystallization reaction temperatures; where Example 21 represents 195 °C, Example 22 represents 205 °C, Example 23 represents 215 °C, and Example 24 represents 225 °C.

[0041] Figure 11XRD patterns of cubic SAPO-20 zeolite molecular sieves synthesized at different hydrothermal crystallization reaction times; among them, Example 25 represents 60 h, Example 26 represents 72 h, Example 27 represents 84 h, and Example 28 represents 96 h.

[0042] Figure 12 XRD patterns of nanoparticle-packed cake-like SAPO-20 zeolite molecular sieves synthesized at different hydrothermal crystallization reaction times; among them, Example 29 represents 60 h, Example 30 represents 72 h, Example 31 represents 84 h, and Example 32 represents 96 h.

[0043] Figure 13 XRD patterns of nanoparticle-packed spherical SAPO-20 zeolite molecular sieves synthesized at different hydrothermal crystallization reaction times; among them, Example 33 represents 60 h, Example 34 represents 72 h, Example 35 represents 84 h, and Example 36 represents 96 h.

[0044] Figure 14 Activity data graphs of highly crystalline SAPO-20 zeolite molecular sieves with cubic, nanoparticle-packed cake-like, and nanoparticle-packed spherical special morphologies prepared in Example 27, Example 31, and Example 35, respectively, after loading Co and used as catalysts for the hydrogenation of carbon oxides to methanol; among them, the catalyst activity data are characterized by the conversion rate of CO 2 , methanol selectivity, and space-time yield. Detailed implementation manners

[0045] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments and drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. 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. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0046] 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 here, 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.

[0047] In the following examples, the experimental methods without specific conditions are generally determined according to national standards; if there are no corresponding national standards, they are carried out according to general standard requirements or general methods.

[0048] In the following examples using aluminum isopropoxide as the aluminum source, ethylene glycol needs to be added as a mineralizer to the system, and the molar ratio of the aluminum source in the system is n(Al 2 O 3 ): n(mineralizer) = 1.0:4.3 for dosing.

[0049] In the following examples and comparative examples, in the expression of "molar ratio of each material Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :TMHD": 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 pseudoboehmite or 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 magnesium trisilicate or tetraethyl orthosilicate; 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.

[0050] Conversion rate = (amount of initial reactant (mol) - amount of unreacted substance (mol)) / amount of initial reactant (mol) × 100%;

[0051] Yield = amount of target product (mol) / amount of initial reactant (mol) × 100%.

[0052] Example 1

[0053] Solution A: Obtained by dissolving 1.3 g of magnesium trisilicate in 8.0 mL of H 2 O;

[0054] Take 1.8 g of high-purity pseudoboehmite AlOOH·nH 2 O and dissolve it in 9.0 mL of H 2 O and mix evenly. Add 2.8 mL of 85 wt% phosphoric acid aqueous solution, stir for 30 min, then add Solution A dropwise, and then stir well for another 30 min. Then add 6.7 mL of N,N,N’,N’-tetramethyl-1,6-hexanediamine and stir for 12 h to obtain a mixture; Put the obtained mixture into a high-pressure reaction kettle and carry out hydrothermal crystallization reaction at 205 °C in an oven for 72 h. After filtration, washing and drying, calcine at 450 °C for 6 h to obtain the product cubic SAPO-20 zeolite molecular sieve. The feeding molar ratio of each material in the system is Al 2 O 3 :H 2 O:P 2 O 5:SiO 2 :TMHD = 0.9:63:1.8:1.0:1.6.

[0055] The crystallinity of the prepared SAPO-20 zeolite molecular sieve is shown in Table 1.

[0056] Example 2

[0057] Solution A: Obtained by dissolving 1.3 g of magnesium trisilicate in 8.0 mL of H 2 O;

[0058] Take 2.0 g of high-purity pseudoboehmite AlOOH·nH 2 O and dissolve it in 9.0 mL of H 2 O, mix evenly, add 2.8 mL of 85 wt% phosphoric acid aqueous solution, stir for 30 min, then dropwise add Solution A, stir for another 30 min, add 6.7 mL of N,N,N’,N’-tetramethyl-1,6-hexanediamine, and stir for 12 h to obtain a mixture; put the obtained mixture into a high-pressure reaction kettle, place it in an oven at 205 °C for hydrothermal crystallization reaction for 72 h, filter, wash, dry, and then calcine at 450 °C for 6 h to obtain the product cubic SAPO-20 zeolite 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 :TMHD = 1.0:63:1.8:1.0:1.6.

[0059] The crystallinity of the prepared SAPO-20 zeolite molecular sieve is shown in Table 1.

[0060] Experimental Example 3

[0061] Solution A: Obtained by dissolving 1.3 g of magnesium trisilicate in 8.0 mL of H 2 O;

[0062] Take 2.2 g of high-purity pseudoboehmite AlOOH·nH 2 O and dissolve it in 9.0 mL of H 2 O, mix evenly, add 2.8 mL of 85 wt% phosphoric acid aqueous solution, stir for 30 min, then dropwise add Solution A, stir for another 30 min, add 6.7 mL of N,N,N’,N’-tetramethyl-1,6-hexanediamine, and stir for 12 h to obtain a mixture; put the obtained mixture into a high-pressure reaction kettle, place it in an oven at 205 °C for hydrothermal crystallization reaction for 72 h, filter, wash, dry, and then calcine at 450 °C for 6 h to obtain the product cubic SAPO-20 zeolite molecular sieve. The molar ratio of each material in the system is Al 2 O3 :H 2 O:P 2 O 5 :SiO 2 :TMHD = 1.1:63:1.8:1.0:1.6。

[0063] The crystallinity of the obtained SAPO-20 zeolite molecular sieve is shown in Table 1.

[0064] Experimental Example 4

[0065] Solution A: Prepared by dissolving 1.3 g of magnesium trisilicate in 8.0 mL of H 2 O;

[0066] Take 2.4 g of high-purity pseudoboehmite AlOOH·nH 2 O and dissolve it in 9.0 mL of H 2 O, mix evenly, add 2.8 mL of 85 wt% phosphoric acid aqueous solution, stir for 30 min, then add Solution A drop by drop. After stirring for another 30 min, add 6.7 mL of N,N,N’,N’-tetramethyl-1,6-hexanediamine, and stir for 12 h to obtain a mixture. The obtained mixture is loaded into a high-pressure reactor and subjected to hydrothermal crystallization reaction at 205 °C in an oven for 72 h. After filtration, washing, and drying, it is calcined at 450 °C for 6 h to obtain the cubic SAPO-20 zeolite molecular sieve product. The molar ratio of each material in the system is Al 2 O 3 :H 2 O:P 2 O 5 :SiO 2 :TMHD = 1.2:63:1.8:1.0:1.6。

[0067] The crystallinity of the obtained SAPO-20 zeolite molecular sieve is shown in Table 1.

[0068] Experimental Example 5

[0069] Solution A: Prepared by dissolving 1.3 g of magnesium trisilicate in 8.0 mL of H 2 O;

[0070] Take 5.5 g of aluminum isopropoxide C 9 H 21 AlO 3 and dissolve it in 7.2 mL of ethylene glycol mineralizer, then dropwise add 9.0 mL of H 2Mix evenly, add 2.8 mL of 85 wt% phosphoric acid aqueous solution, stir for 30 min, then add solution A drop by drop. After stirring for another 30 min, add 6.7 mL of N,N,N’,N’-tetramethyl-1,6-hexanediamine, and stir for 12 h to obtain a mixture. Put the obtained mixture into a high-pressure reactor, place it in an oven at 205 °C for hydrothermal crystallization reaction for 72 h. After filtration, washing, and drying, calcine at 450 °C for 6 h to obtain a product of nanoparticle-packed cake-like SAPO-20 zeolite 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 :TMHD:mineralizer = 0.9:63:1.8:1.0:1.6:3.87.

[0071] The crystallinity of the prepared SAPO-20 zeolite molecular sieve is shown in Table 1.

[0072] Experimental Example 6

[0073] Solution A: Obtained by dissolving 1.3 g of magnesium trisilicate in 8.0 mL of H 2 O.

[0074] Take 6.1 g of aluminum isopropoxide C 9 H 21 AlO 3 Dissolve it in 8.0 mL of ethylene glycol mineralizer, drop in 9.0 mL of H 2 O, mix evenly, add 2.8 mL of 85 wt% phosphoric acid aqueous solution, stir for 30 min, then add solution A drop by drop. After stirring for another 30 min, add 6.7 mL of N,N,N’,N’-tetramethyl-1,6-hexanediamine, and stir for 12 h to obtain a mixture. Put the obtained mixture into a high-pressure reactor, place it in an oven at 205 °C for hydrothermal crystallization reaction for 72 h. After filtration, washing, and drying, calcine at 450 °C for 6 h to obtain a product of nanoparticle-packed cake-like SAPO-20 zeolite 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 :TMHD:mineralizer = 1.0:63:1.8:1.0:1.6:4.30.

[0075] The crystallinity of the prepared SAPO-20 zeolite molecular sieve is shown in Table 1.

[0076] Experimental Example 7

[0077] Solution A: Prepared by dissolving 1.3 g of magnesium trisilicate in 8.0 mL of H 2 O;

[0078] Take 6.7 g of aluminum isopropoxide C 9 H 21 AlO 3 Dissolve it in 8.8 mL of ethylene glycol mineralizer, add dropwise 9.0 mL of H 2 O, mix evenly, add 2.8 mL of 85 wt% phosphoric acid aqueous solution, stir for 30 min, then add Solution A drop by drop. After stirring for another 30 min, add 6.7 mL of N,N,N’,N’-tetramethyl-1,6-hexanediamine, and stir for 12 h to obtain a mixture; put the obtained mixture into a high-pressure reaction kettle, place it in an oven at 205 °C for hydrothermal crystallization reaction for 72 h, filter, wash, dry, and then calcine at 450 °C for 6 h to obtain a product of nano-particle-packed cake-like SAPO-20 zeolite 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 :TMHD:mineralizer = 1.1:63:1.8:1.0:1.6:4.73.

[0079] The crystallinity of the prepared SAPO-20 zeolite molecular sieve is shown in Table 1.

[0080] Experimental Example 8

[0081] Solution A: Prepared by dissolving 1.3 g of magnesium trisilicate in 8.0 mL of H 2 O;

[0082] Take 7.4 g of aluminum isopropoxide C 9 H 21 AlO 3 Dissolve it in 9.6 mL of ethylene glycol mineralizer, add dropwise 9.0 mL of H 2 O, mix evenly, add 2.8 mL of 85 wt% phosphoric acid aqueous solution, stir for 30 min, then add Solution A drop by drop. After stirring for another 30 min, add 6.7 mL of N,N,N’,N’-tetramethyl-1,6-hexanediamine, and stir for 12 h to obtain a mixture; put the obtained mixture into a high-pressure reaction kettle, place it in an oven at 205 °C for hydrothermal crystallization reaction for 72 h, filter, wash, dry, and then calcine at 450 °C for 6 h to obtain a product of nano-particle-packed cake-like SAPO-20 zeolite molecular sieve. The molar ratio of each material in the system is Al 2 O 3 :H 2 O:P 2 O 5 :SiO2 :TMHD:Mineralizer = 1.2:63:1.8:1.0:1.6:5.16.

[0083] The crystallinity of the prepared SAPO-20 zeolite molecular sieve is shown in Table 1.

[0084] Experimental Example 9

[0085] Solution B: Obtained by dissolving 3.8 g of tetraethyl orthosilicate in 8.0 mL of H 2 O;

[0086] Take 5.5 g of aluminum isopropoxide C 9 H 21 AlO 3 Dissolve it in 7.2 mL of ethylene glycol mineralizer, dropwise add 9.0 mL of H 2 O and mix evenly. Add 2.8 mL of 85 wt% phosphoric acid aqueous solution, stir for 30 min, then gradually add Solution B dropwise. After stirring for another 30 min, add 6.7 mL of N,N,N’,N’-tetramethyl-1,6-hexanediamine, and stir for 12 h to obtain a mixture; put the obtained mixture into a high-pressure reaction kettle, place it in an oven at 205 °C for hydrothermal crystallization reaction for 72 h, filter, wash, and dry, and then calcine at 450 °C for 6 h to obtain the product, nanoparticle-packed cake-like SAPO-20 zeolite 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 :TMHD:Mineralizer = 0.9:63:1.8:1.0:1.6:3.87.

[0087] The crystallinity of the prepared SAPO-20 zeolite molecular sieve is shown in Table 1.

[0088] Experimental Example 10

[0089] Solution B: Obtained by dissolving 3.8 g of tetraethyl orthosilicate in 8.0 mL of H 2 O;

[0090] Take 6.1 g of aluminum isopropoxide C 9 H 21 AlO 3 Dissolve it in 8.0 mL of ethylene glycol mineralizer, dropwise add 9.0 mL of H 2Mix evenly, add 2.8 mL of 85 wt% phosphoric acid aqueous solution, stir for 30 min, then add solution B drop by drop. After stirring for another 30 min, add 6.7 mL of N,N,N’,N’-tetramethyl-1,6-hexanediamine, and stir for 12 h to obtain a mixture. Load the obtained mixture into a high-pressure reactor, place it in an oven at 205 °C for hydrothermal crystallization reaction for 72 h. After filtration, washing, and drying, calcine at 450 °C for 6 h to obtain a product of nanoparticle-packed cake-like SAPO-20 zeolite 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 :TMHD:mineralizer = 1.0:63:1.8:1.0:1.6:4.30.

[0091] The crystallinity of the prepared SAPO-20 zeolite molecular sieve is shown in Table 1.

[0092] Experimental Example 11

[0093] Solution B: Prepared by dissolving 3.8 g of tetraethyl orthosilicate in 8.0 mL of H 2 O.

[0094] Take 6.7 g of aluminum isopropoxide C 9 H 21 AlO 3 Dissolve it in 8.8 mL of ethylene glycol mineralizer, drop in 9.0 mL of H 2 O, mix evenly, add 2.8 mL of 85 wt% phosphoric acid aqueous solution, stir for 30 min, then add solution B drop by drop. After stirring for another 30 min, add 6.7 mL of N,N,N’,N’-tetramethyl-1,6-hexanediamine, and stir for 12 h to obtain a mixture. Load the obtained mixture into a high-pressure reactor, place it in an oven at 205 °C for hydrothermal crystallization reaction for 72 h. After filtration, washing, and drying, calcine at 450 °C for 6 h to obtain a product of nanoparticle-packed cake-like SAPO-20 zeolite 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 :TMHD:mineralizer = 1.1:63:1.8:1.0:1.6:4.13.

[0095] The crystallinity of the prepared SAPO-20 zeolite molecular sieve is shown in Table 1.

[0096] Experimental Example 12

[0097] Solution B: Prepared by dissolving 3.8 g of tetraethyl orthosilicate in 8.0 mL of H 2 O;

[0098] Take 7.4 g of aluminum isopropoxide C 9 H 21 AlO 3 Dissolve it in 9.6 mL of ethylene glycol mineralizer, dropwise add 9.0 mL of H 2 O, mix evenly, add 2.8 mL of 85 wt% phosphoric acid aqueous solution, stir for 30 min, then dropwise add Solution B, stir well for another 30 min, add 6.7 mL of N,N,N’,N’-tetramethyl-1,6-hexanediamine, and stir for 12 h to obtain a mixture; put the obtained mixture into a high-pressure reactor, place it in an oven at 205 °C for hydrothermal crystallization reaction for 72 h, filter, wash, dry, and then calcine at 450 °C for 6 h to obtain a product of nanoparticle-packed cake-like SAPO-20 zeolite 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 :TMHD:mineralizer = 1.2:63:1.8:1.0:1.6:5.16.

[0099] The crystallinity of the prepared SAPO-20 zeolite molecular sieve is shown in Table 1.

[0100] Experimental Examples 13 - 16

[0101] The preparation method of the products in Examples 13 - 16 is the same as that in Example 3, except that the hydrothermal crystallization reaction temperature is different.

[0102] The hydrothermal crystallization reaction temperature in Example 13 is 195 °C.

[0103] The hydrothermal crystallization reaction temperature in Example 14 is 205 °C.

[0104] The hydrothermal crystallization reaction temperature in Example 15 is 215 °C.

[0105] The hydrothermal crystallization reaction temperature in Example 16 is 225 °C.

[0106] The crystallinity of the prepared SAPO-20 zeolite molecular sieve is shown in Table 1.

[0107] Experimental Examples 17 - 20

[0108] The preparation method of the products in Examples 17 - 20 is the same as that in Example 8, except that the hydrothermal crystallization reaction temperature is different.

[0109] The hydrothermal crystallization reaction temperature of Example 17 is 195 °C.

[0110] The hydrothermal crystallization reaction temperature of Example 18 is 205 °C.

[0111] The hydrothermal crystallization reaction temperature of Example 19 is 215 °C.

[0112] The hydrothermal crystallization reaction temperature of Example 20 is 225 °C.

[0113] The crystallinity of the obtained SAPO-20 zeolite molecular sieve is shown in Table 1.

[0114] Experimental Examples 21 - Experimental Example 24

[0115] The preparation method of the products in Examples 21 - 24 is the same as that in Example 11, except that the hydrothermal crystallization reaction temperature is different.

[0116] The hydrothermal crystallization reaction temperature of Example 21 is 195 °C.

[0117] The hydrothermal crystallization reaction temperature of Example 22 is 205 °C.

[0118] The hydrothermal crystallization reaction temperature of Example 23 is 215 °C.

[0119] The hydrothermal crystallization reaction temperature of Example 24 is 225 °C.

[0120] The crystallinity of the obtained SAPO-20 zeolite molecular sieve is shown in Table 1.

[0121] Examples 25 - Example 28

[0122] The preparation method of the products in Examples 25 - 28 is the same as that in Example 15, except that the hydrothermal crystallization reaction time is different.

[0123] The hydrothermal crystallization reaction time of Example 25 is 60 h.

[0124] The hydrothermal crystallization reaction time of Example 26 is 72 h.

[0125] The hydrothermal crystallization reaction time of Example 27 is 84 h.

[0126] The hydrothermal crystallization reaction time of Example 28 is 96 h.

[0127] The crystallinity of the obtained SAPO-20 zeolite molecular sieve is shown in Table 1.

[0128] Examples 29 - Example 32

[0129] The preparation method of the products in Examples 29 - 32 is the same as that in Example 19, except that the hydrothermal crystallization reaction time is different.

[0130] The hydrothermal crystallization reaction time of Example 29 was 60 h.

[0131] The hydrothermal crystallization reaction time of Example 30 was 72 h.

[0132] The hydrothermal crystallization reaction time of Example 31 was 84 h.

[0133] The hydrothermal crystallization reaction time of Example 32 was 96 h.

[0134] The crystallinity of the obtained SAPO-20 zeolite molecular sieve is shown in Table 1.

[0135] Examples 33 - 36

[0136] The preparation method of the products of Examples 33 - 36 was the same as that of Example 23, except that the hydrothermal crystallization reaction time was different.

[0137] The hydrothermal crystallization reaction time of Example 33 was 60 h.

[0138] The hydrothermal crystallization reaction time of Example 34 was 72 h.

[0139] The hydrothermal crystallization reaction time of Example 35 was 84 h.

[0140] The hydrothermal crystallization reaction time of Example 36 was 96 h.

[0141] The crystallinity of the obtained SAPO-20 zeolite molecular sieve is shown in Table 1.

[0142] Comparative Example 1

[0143] The spherical hierarchical pore SAPO-20 zeolite molecular sieve was prepared by the method reported in Example 23 of the Chinese patent "Preparation Method and Application of a Spherical Hierarchical Pore SAPO-20 Zeolite Molecular Sieve" with the publication number CN114702041B. The specific parameters are shown in Table 1.

[0144] The crystallinity (%) and nitrogen adsorption of the above examples were tested. Crystallinity calculation method: The crystallinity was tested using an X-ray diffractometer, and the calculation formula was: crystallinity = (diffraction peak intensity / total intensity) * 100%, and the data was processed using jade software. Nitrogen adsorption was measured using a physical adsorption instrument to obtain S BET The reaction parameters and specific crystallinity data of the above examples are shown in Table 1.

[0145] The products of the above examples and comparative examples were subjected to XRD testing and crystallinity calculation, and the results are shown in Table 1.

[0146] Table 1 Preparation parameters and crystallinity of the products of the above examples and comparative examples

[0147]

[0148]

[0149] Results and Discussion:

[0150] The SEM image of the highly crystalline SAPO-20 zeolite product obtained in Example 27 is as shown in Figure 1 the figure, and its N 2 adsorption-desorption isotherm and pore size distribution curve are as shown in Figure 4 the figure. It can be seen that the SAPO-20 zeolite product obtained by the method of the present invention is cubic, has a microporous distribution, and the pore size distribution is at 2.95 nm.

[0151] The SEM image of the highly crystalline SAPO-20 zeolite product obtained in Example 31 is as shown in Figure 2 the figure, and its N 2 adsorption-desorption isotherm and pore size distribution curve are as shown in Figure 4 the figure. It can be seen that the SAPO-20 zeolite product obtained by the method of the present invention is a cake-like shape stacked by nanoparticles, has a hierarchical pore distribution, and the pore size distribution is at 7.55 nm and 30.77 nm.

[0152] The SEM image of the highly crystalline SAPO-20 zeolite product obtained in Example 35 is as shown in Figure 3 the figure, and its N 2 adsorption-desorption isotherm and pore size distribution curve are as shown in Figure 4 the figure. It can be seen that the SAPO-20 zeolite product obtained by the method of the present invention is a spherical shape stacked by nanoparticles, has a mesoporous distribution, and the pore size distribution is at 31.27 nm.

[0153] Experimental Examples 1-4 compared whether cubic SAPO-20 zeolite could be synthesized under the condition of using magnesium trisilicate as the silicon source and pseudoboehmite as the aluminum source with different Al 2 O 3 :P 2 O 5 ratios. It can be known from the crystallinity in Table 1 and the XRD pattern of Figure 5 that microporous cubic SAPO-20 zeolite can be hydrothermally synthesized when the aluminum-phosphorus ratio is in the range of (1.0 - 1.2):1.8, but the crystallinity is the highest when Al 2 O 3 :P 2 O 5 = 1.1:1.8. Therefore, when Al 2 O 3 :P 2 O 5 = 1.1:1.8, it is beneficial to the synthesis of microporous cubic SAPO-20.

[0154] Experimental Examples 5 - 8 compared whether SAPO - 20 zeolite could be synthesized under the condition that magnesium trisilicate was used as the silicon source and aluminum isopropoxide was used as the aluminum source, with different Al 2 O 3 :P 2 O 5 ratios. From the crystallinity in Table 1 and the Figure 6 XRD patterns, it can be seen that porous nanoscale particle - packed cake - shaped SAPO - 20 zeolite can be hydrothermally synthesized when the aluminum - phosphorus ratio is in the range of (0.9 - 1.2):1.8. However, when Al 2 O 3 :P 2 O 5 = 1.2:1.8, the crystallinity is the highest. Therefore, when Al 2 O 3 :P 2 O 5 = 1.1:1.8, it is beneficial to the synthesis of porous nanoscale particle - packed cake - shaped SAPO - 20.

[0155] Experimental Examples 9 - 12 compared whether SAPO - 20 zeolite could be synthesized under the condition that tetraethyl orthosilicate was used as the silicon source and aluminum isopropoxide was used as the aluminum source, with different Al 2 O 3 :P 2 O 5 ratios. From the crystallinity in Table 1 and the Figure 7 XRD patterns, it can be seen that mesoporous nanoscale particle - packed spherical SAPO - 20 zeolite can be hydrothermally synthesized when the aluminum - phosphorus ratio is in the range of (1.0 - 1.1):1.8. However, when Al 2 O 3 :P 2 O 5 = 1.1:1.8, the crystallinity is the highest. Therefore, when Al 2 O 3 :P 2 O 5 = 1.1:1.8, it is beneficial to the synthesis of mesoporous nanoscale particle - packed spherical SAPO - 20.

[0156] Experimental Examples 13 - 24 compared whether it was beneficial to the synthesis of SAPO - 20 zeolite in the system at different crystallization temperatures. From the crystallinity in Table 1 and Figure 8 、 Figure 9 、 Figure 10From the XRD patterns, it can be seen that the crystallization degree is the highest in the system with a crystallization temperature of 215 °C, which is beneficial to the synthesis of microporous cubic SAPO-20, porous nanoparticle-packed cake-like SAPO-20, and mesoporous nanoparticle-packed spherical SAPO-20. However, too high or too low temperature will affect the reduction of the characteristic peak intensity of the XRD pattern, and the corresponding crystallization degree is also quite low. Therefore, the crystallization temperature of 215 °C is selected as the optimal temperature.

[0157] Experimental Examples 25-36 compared whether different crystallization times are beneficial to the synthesis of SAPO-20 zeolite in the system. Through the crystallization degree in Table 1 and Figure 11 , Figure 12 , Figure 13 From the XRD patterns, it can be seen that SAPO-20 zeolites with different morphologies can be synthesized within the range of 72-96 h of crystallization time. And when the crystallization time is 84 h, it is beneficial to the synthesis of microporous cubic SAPO-20, porous nanoparticle-packed cake-like SAPO-20, and mesoporous nanoparticle-packed spherical SAPO-20. However, too long or too short crystallization time will affect the reduction of the characteristic peak intensity of the XRD pattern, and the corresponding crystallization degree is also quite low. Therefore, the crystallization time of 84 h is selected as the optimal crystallization time.

[0158] Comparative Example 1 and Experimental Examples 27, 31, and 35 compared the highly crystalline spherical-like SAPO-20 synthesized by the prior art and the highly crystalline, morphology-controllable SAPO-20 zeolite molecular sieve prepared by the synthesis scheme of the present invention. Through the crystallization degree in Table 1 and Figure 11 , Figure 12 and Figure 13 From the XRD patterns, it can be seen that under different formulations and different material ratios, the crystallization degree of SAPO-20 zeolite is as high as 99.9%, without obvious differences. However, compared with the literature experimental scheme, the present invention prepares a special morphology of SAPO-20 molecular sieve with high crystallinity and morphologies of cubic, nanoparticle-packed cake-like, and nanoparticle-packed spherical by simply regulating different silicon sources and aluminum sources. And the SAPO-20 molecular sieves with different morphologies have their special pore structures and pore distributions.

[0159] Application Example 1

[0160] The highly crystalline SAPO-20 zeolite molecular sieves with morphologies of cubic, nanoparticle-packed cake-like, and nanoparticle-packed spherical prepared in Experimental Examples 27, 31, and 35 were all loaded with Co to prepare Co-SAPO-20 molecular sieve catalysts for the catalytic hydrogenation of carbon oxides to alcohols, and the activities of the Co-SAPO-20 molecular sieve catalysts were measured.

[0161] Specific preparation process of Co-SAPO-20 molecular sieve catalyst: Take a certain amount of cubic SAPO-20 zeolite sample with a specific morphology as the catalyst support, and introduce metal species by the equal-volume impregnation method according to 5 wt.% of the support mass. Prepare a solution according to the measured water inlet rate and uniformly drop it onto the surface of the zeolite molecular sieve. The metal precursor is mainly nitrate (cobalt nitrate selected in this application example). After the impregnated sample is dried in air at room temperature overnight, it is dried in an oven at 80-120 °C and finally calcined at 450 °C for 4 h. Before use, the catalyst needs to be reduced: After screening a certain amount of the catalyst to the target mesh number, it is reduced at 400 °C in a hydrogen atmosphere for 4 h. Then the Co-SAPO-20 (cubic) molecular sieve catalyst can be obtained.

[0162] According to the foregoing method, Co-SAPO-20 (cake-shaped) molecular sieve catalyst and Co-SAPO-20 (spherical-shaped) molecular sieve catalyst were prepared by loading Co on SAPO-20 zeolite molecular sieves in the form of nanoparticle-packed cakes and nanoparticle-packed spheres respectively, and the CO 2 catalytic activity for hydrogenation of CO to methanol over zeolite molecular sieve catalysts with different morphologies of SAPO-20 supported metals was tested. The catalyst activity data and data graphs are shown in Table 2 and Figure 14 .

[0163] It can be seen that the Co-SAPO-20 molecular sieve catalysts prepared by loading Co on the special-shaped SAPO-20 zeolite molecular sieves with high crystallinity and in the forms of cubic, nanoparticle-packed cake-shaped and nanoparticle-packed spherical shapes all have high CO 2 conversion rates, methanol selectivities and space-time yields in the reaction of catalytic hydrogenation of carbon oxides to alcohol compounds. Among them, after loading the noble metal Co on SAPO-20 with a nanoparticle-packed spherical shape, the CO 2 selectivity can be as high as 33.88%; after loading the noble metal Co on cubic SAPO-20, the methanol selectivity can be as high as 93.42%. It can be seen that the Co-SAPO-20 molecular sieve catalysts prepared by loading Co on the special-shaped SAPO-20 zeolite molecular sieves with high crystallinity and in the forms of cubic, nanoparticle-packed cake-shaped and nanoparticle-packed spherical shapes can all achieve excellent performance.

[0164] Table 2. Activity comparison of catalytic activities of different catalysts for CO 2 hydrogenation to methanol

[0165]

[0166] The above are only the preferred specific embodiments 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 within the protection scope of the present invention.

Claims

1. A method for preparing a morphology-controlled high-crystallinity SAPO-20 zeolite molecular sieve, characterized in that: The steps include: An aluminum source, a phosphorus source, a silicon source, and an organic amine structure directing agent are sequentially added to water, and each raw material is stirred evenly before adding other raw materials; after all raw materials are added, stirring is continued for 12 hours, and a hydrothermal crystallization reaction is carried out at a temperature of 195-225° C. for a reaction time of 60-96 hours. After the product is taken out, it is washed with water until the pH is neutral, dried, and calcined at 450° C. for 6 hours to obtain a SAPO-20 zeolite molecular sieve with different morphologies; The aluminum source, the phosphorus source, the silicon source, and the organic amine template are calculated by using Al2O3, P2O5, SiO2, and TMHD as raw material feed amounts, and the raw materials are added according to the molar ratio of Al2O3:H2O:P2O5:SiO2:TMHD=(0.9-1.2):63:1.8:1.0:1.6; The morphology of SAPO-20 zeolite molecular sieve can be controlled by adjusting the types of different aluminum sources and silicon sources. The adjustment method is as follows: When pseudo-boehmite is selected as the aluminum source and magnesium trisilicate is selected as the silicon source, its morphology is cubic; When aluminum isopropoxide is selected as the aluminum source and magnesium trisilicate is selected as the silicon source, the morphology is a cake-like shape of nanoparticle stacking; When aluminum isopropoxide is selected as the aluminum source and tetraethyl silicate is selected as the silicon source, the morphology is nanoparticle stacking spherical shape.

2. The preparation method according to claim 1, characterized in that: The phosphorus source is an 85% wt phosphoric acid aqueous solution.

3. The preparation method according to claim 1, characterized in that: The organic amine structure directing agent is N,N,N',N'-tetramethyl-1,6-hexanediamine.

4. The preparation method according to claim 1, characterized in that: The temperature of the crystallization reaction is preferably 215° C.; the time of the crystallization reaction is preferably 84 h.

5. The preparation method according to claim 1, characterized in that: In the method using aluminum isopropoxide as the aluminum source, ethylene glycol needs to be added as a mineralizer, and the molar ratio of the aluminum source to the mineralizer is 1.0:4.

3.

6. The preparation method according to claim 1, characterized in that: The cubic SAPO-20 zeolite has a microporous structure with a pore size distribution of 2.95 nm.

7. The preparation method according to claim 1, characterized in that: The nano-particle stacked cake-shaped SAPO-20 zeolite has a multi-level pore structure, and the pore diameters are distributed between 7.55 nm and 30.77 nm.

8. The preparation method according to claim 1, characterized in that: The nanoparticle-stacked spherical SAPO-20 zeolite has a mesoporous structure with a pore size distribution of 31.27 nm.

9. Use of a high-crystallinity SAPO-20 zeolite molecular sieve loaded with transition metals or transition metal oxides prepared by the method according to any one of claims 1 to 8 in a carbon oxide hydrogenation reaction.

10. The use according to claim 9, characterized in that: The transition metal is a Co-containing metal or a Co-containing metal oxide.

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