SCM-29 molecular sieve and preparation method and application thereof
阅读说明：本技术 Scm-29分子筛及其制备方法和应用 (SCM-29 molecular sieve and preparation method and application thereof ) 是由 乔健 袁志庆 刘松霖 王振东 滕加伟 于 2019-10-08 设计创作，主要内容包括：本发明公开了一种SCM-29分子筛及其制备方法和应用。该分子筛包含如下摩尔比的化学组成：Al-2O-3：mSiO-2：nP-2O-5,其中0.001≤m≤0.25,0.75≤n≤1.25,所述SCM-29分子筛具有独特的X射线衍射数据。本发明的SCM-29分子筛是一种新型分子筛,具有新颖的三维开放骨架结构,SCM-29分子筛可用于甲醇下游产品的工业生产,表现出良好的性能。(The invention discloses an SCM-29 molecular sieve and a preparation method and application thereof. The molecular sieve comprises the following chemical compositions in molar ratio: al (Al) 2 O 3 ：mSiO 2 ：nP 2 O 5 Wherein m is more than or equal to 0.001 and less than or equal to 0.25, n is more than or equal to 0.75 and less than or equal to 1.25, and the SCM-29 molecular sieve has unique X-ray diffraction data. The SCM-29 molecular sieve is a novel molecular sieve, has a novel three-dimensional open framework structure, and can be used for the industry of downstream products of methanolAnd (3) production, and shows good performance.)
1. An SCM-29 molecular sieve comprising the chemical composition in mole ratios as follows: al (Al)2O3：mSiO2：nP2O5Wherein m is 0.001-0.25, n is 0.75-1.25, said SCM-29 molecular sieve comprising the X-ray diffraction data shown in the following table:
。
2. The SCM-29 molecular sieve of claim 1, wherein: the SCM-29 molecular sieve further comprises X-ray diffraction data as shown in the following table:
。
3. A SCM-29 molecular sieve according to claim 1 or 2, characterized in that: the SCM-29 molecular sieve further comprises X-ray diffraction data as shown in the following table:
。
4. A process for the preparation of the SCM-29 molecular sieve as claimed in any of claims 1 to 3 comprising:
1) mixing an aluminum source, a solvent S1, a phosphorus source and a mixed template agent, and precipitating to obtain a mixed material;
2) adding a silicon source and a solvent S2 into the mixed material obtained in the step 1), mixing and preprocessing to obtain a crystallized mixture;
3) and 2) carrying out crystallization reaction on the crystallization mixture obtained in the step 2) to obtain the SCM-29 molecular sieve.
5. The method of claim 4, wherein: in the step 1), the aluminum source is at least one selected from aluminate, meta-aluminate, aluminum salt, aluminum hydroxide, aluminum oxide or aluminum-containing mineral; the phosphorus source is at least one of phosphoric acid, ammonium monohydrogen phosphate or ammonium dihydrogen phosphate; the aluminum source is preferably at least one of aluminate, meta-aluminate or aluminum salt; the phosphorus source is preferably at least one of phosphoric acid and ammonium monohydrogen phosphate; in the step 2), the silicon source is at least one selected from organosilicon, amorphous silica, silica sol, white carbon black, silica gel, diatomite or water glass; the silicon source is preferably at least one of amorphous silica, silica sol or white carbon black.
6. The method of claim 4, wherein: in the step 1), the solvent S1 is at least one selected from methanol, ethanol, glycol, butanol and water; the solvent S1 is preferably at least one of ethanol and water; in the step 2), the solvent S2 is at least one selected from N, N-dimethylformamide, N-dimethylacetamide, N-diethylformamide and N, N-dibutylformamide; the solvent S2 is preferably at least one of N, N-dimethylformamide and N, N-dimethylacetamide.
7. The method of claim 4, wherein: in the step 1), the mixed template comprises a template R1 and a template R2; wherein the template agent R1 is selected from at least one of tetraethylammonium bromide, tetraethylammonium hydroxide, tetrapropylammonium bromide, tetrapropylammonium hydroxide, tetrabutylammonium bromide and tetrabutylammonium hydroxide, and the template agent R2 is selected from at least one of 1, 10-phenanthroline, 2-bipyridine, 4-bipyridine, piperazine, cyclohexylamine, triethylamine, n-butylamine, di-n-propylamine, diisopropylamine, ethylenediamine and ethylamine; preferably, the templating agent R1 is selected from at least one of tetraethylammonium bromide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide and tetrabutylammonium hydroxide, and the templating agent R2 is selected from at least one of piperazine, cyclohexylamine, triethylamine and ethylenediamine.
8. The method of claim 4, wherein: the aluminum source, the phosphorus source and the silicon source are calculated by oxides, and the molar ratio of the used raw materials is as follows: SiO 22：Al2O3＝0.001～1，P2O5：Al2O30.5-1.5, mixing a template agent: al (Al)2O30.1-60 (solvent S1+ solvent S2): al (Al)2O31-500 parts of; preferably, SiO2：Al2O3＝0.01～0.5，P2O5：Al2O30.75-1.25, mixing a template agent: al (Al)2O30.5-30 (solvent S1+ solvent S2): al (Al)2O310-150; more preferably, SiO2：Al2O3＝0.05～0.1，P2O5：Al2O30.95-1.05, mixing a template agent: al (Al)2O31-15, (solvent S1+ solvent S2): al (Al)2O320-80 parts of ═ a; the molar ratio of the template R1 to the template R2 in the mixed template is R1: r2 is 0.1-10: 1, the molar ratio of the solvent S2 to the solvent S1 is S2: s1 is 0.1-10: 1; preferably R1: r2 is 1.0-5.0: 1, S2: s1 is 0.75-2.5: 1.
9. the method of claim 4, wherein: the mixing time in the step 1) is 0.5-5 h, and the settling time is 2-12 h; in the step 2), the mixing time is 0.5-5 h, and the pretreatment conditions are as follows: treating for 2-12 h at 60-120 ℃; in the step 3), the crystallization reaction conditions of the crystallization mixture are as follows: crystallizing at 120-220 ℃ for 12 h-15 d, preferably: crystallizing for 24 h-10 d at 140-200 ℃; more preferably: crystallizing at 160-180 ℃ for 54 h-5 d.
10. A molecular sieve composition comprising the SCM-29 molecular sieve of any of claims 1-3 or the SCM-29 molecular sieve prepared according to the method of any of claims 4-9, and a binder.
11. Use of a SCM-29 molecular sieve as claimed in any of claims 1 to 3, a SCM-29 molecular sieve produced by a process for the preparation of a SCM-29 molecular sieve as claimed in any of claims 4 to 9, or a molecular sieve composition as claimed in claim 10 as a catalyst.
12. Use according to claim 11, characterized in that: the method is used for the reaction of preparing hydrocarbon from methanol.
Technical Field
The invention relates to a molecular sieve, a preparation method and application thereof, in particular to an SCM-29 molecular sieve, a preparation method and application thereof.
Background
Porous materials are a class of solid compounds with regular pore structure, zeolite molecular sieve having pore channel diameters generally below 2nm as defined by the International Union of Pure and Applied Chemistry (IUPAC), and are therefore classified as microporous materials, mainly characterized by selective adsorption, whose unique channel system confers the ability to sieve molecules of different sizes, which is why such materials are also called "molecular sieves". And the material has wide pore size distribution range and rich and diverse topological structures, and is widely applied to the fields of adsorption, heterogeneous catalysis, carriers of various object molecules, ion exchange and the like.
Zeolite molecular sieves are crystalline silicate materials, typically composed of silicon-oxygen tetrahedra [ SiO ]4]4-And alundum tetrahedron [ AlO4]5-Linked by a common oxygen atom, collectively known as TO4The tetrahedron, in which the silicon element can also be isomorphously substituted by other elements, especially some trivalent or tetravalent elements such as Al, B, Ga, Ge, Ti, etc., has wide application in the fields of catalysis, adsorption, ion exchange, etc. due to some specificities in their structure and chemical properties. One key factor determining the application performance of molecular sieve is the characteristics of its pore canal or cage cavity, which are determined by the intrinsic crystal structure of molecular sieve, so obtaining molecular sieve with new crystal structure is very important for developing molecular sieve application。
Some molecular sieves are available in nature, however, most of the molecular sieves that find practical application in the catalytic field are obtained by artificial synthesis. In the last 40 th century, Barrer and the like synthesized artificial zeolite which does not exist in nature for the first time in a laboratory, and in nearly more than ten years thereafter, Milton, Breck, Sand and the like added alkali metal or alkaline earth metal hydroxide into aluminosilicate gel by adopting a hydrothermal technology to prepare A-type, X-type, L-type and Y-type zeolites, mordenite and the like; in the early sixties of the last century, with the introduction of organic base cations, a series of zeolite molecular sieves with completely new structures, such as ZSM-n series (ZSM-5(US 3702886), ZSM-11(US 3709979), ZSM-23(US 4076842), ZSM-35(US 4016245) and the like) zeolite molecular sieves, were prepared.
In 1982, scientists Wilson S.T. and Flarigen E.M. of United states of America Union carbide (UCC) used aluminum source, phosphorus source and organic template agent to successfully synthesize and develop a brand-new molecular sieve family-aluminum phosphate molecular sieve AlPO4N, n represents the model number (US 4310440). Two years later, UCC in AlPO4Based on-n, Si atoms are used for partially replacing Al atoms and P atoms in an AlPO framework, and another series of silicoaluminophosphate molecular sieves SAPO-n are successfully prepared, wherein n represents the type (US4440871, US 4499327).
Molecular sieves of known topological structures are prepared by hydrothermal or solvothermal synthesis. A typical hydrothermal or solvothermal synthesis method comprises the main steps of uniformly mixing reactants such as a metal source, a nonmetal source, an organic template agent and a solvent to obtain an initial sol, namely a crystallized mixture, then placing the crystallized mixture into a reaction kettle with a polytetrafluoroethylene lining and a stainless steel outer wall, sealing the reaction kettle, and then carrying out crystallization reaction at a certain temperature under a certain autogenous pressure, like the process of earth rock-making, namely the process of precipitating molecular sieve crystals from the crystallized mixture.
To date, no material having the same X-ray diffraction crystal structure as the SCM-29 molecular sieve has been found.
Disclosure of Invention
The invention provides a novel SCM-29 molecular sieve which is not related in the prior art, a preparation method and application thereof, and the molecular sieve has a novel three-dimensional open framework structure and can be used for industrial production of downstream products of methanol.
In a first aspect, the present invention provides a SCM-29 molecular sieve comprising the chemical composition in the following molar ratios: al (Al)2O3：mSiO2：nP2O5Wherein m is 0.001-0.25, n is 0.75-1.25, said SCM-29 molecular sieve comprising the X-ray diffraction data shown in the following table:
further, the SCM-29 molecular sieve also contains X-ray diffraction data as shown in the following table:
2Theta
relative Strength, (I/I0). times.100
11.88±0.1
10-20
24.79±0.1
10-20
33.09±0.02
5-50
37.42±0.02
10-20
40.79±0.02
5-50
46.07±0.02
10-20
。
Still further, the SCM-29 molecular sieve further comprises X-ray diffraction data as shown in the following table:
2Theta
relative Strength, (I/I0). times.100
17.08±0.1
10-20
20.12±0.1
10-50
21.16±0.1
10-50
23.61±0.1
10-20
32.44±0.02
5-50
34.75±0.02
5-50
。
The invention provides a preparation method of the SCM-29 molecular sieve, which comprises the following steps:
1) mixing an aluminum source, a solvent S1, a phosphorus source and a mixed template agent, and precipitating to obtain a mixed material;
2) adding a silicon source and a solvent S2 into the mixed material obtained in the step 1), mixing and preprocessing to obtain a crystallized mixture;
3) and 2) carrying out crystallization reaction on the crystallization mixture obtained in the step 2) to obtain the SCM-29 molecular sieve.
In the step 1), the aluminum source is at least one selected from aluminate, meta-aluminate, aluminum salt, aluminum hydroxide, aluminum oxide or aluminum-containing mineral; the phosphorus source is at least one selected from phosphoric acid, ammonium monohydrogen phosphate and ammonium dihydrogen phosphate.
Preferably, the aluminum source is selected from at least one of aluminate, meta-aluminate or aluminum salt (such as aluminum sulfate, aluminum nitrate, aluminum isopropoxide); the phosphorus source is at least one of phosphoric acid and ammonium monohydrogen phosphate.
In step 1), the solvent S1 is selected from at least one of methanol, ethanol, ethylene glycol, butanol and water (such as deionized water); preferably at least one of ethanol and water.
In the step 1), the mixed template comprises a template R1 and a template R2.
Wherein the template agent R1 is selected from at least one of tetraethylammonium bromide, tetraethylammonium hydroxide, tetrapropylammonium bromide, tetrapropylammonium hydroxide, tetrabutylammonium bromide and tetrabutylammonium hydroxide, and the template agent R2 is selected from at least one of 1, 10-phenanthroline, 2-bipyridine, 4-bipyridine, piperazine, cyclohexylamine, triethylamine, n-butylamine, di-n-propylamine, diisopropylamine, ethylenediamine and ethylamine.
Further, the template agent R1 is selected from at least one of tetraethylammonium bromide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide and tetrabutylammonium hydroxide, and the template agent R2 is selected from at least one of piperazine, cyclohexylamine, triethylamine and ethylenediamine.
In the step 2), the silicon source is at least one selected from organosilicon, amorphous silica, silica sol, white carbon black, silica gel, diatomite or water glass; preferably at least one of amorphous silica, silica sol or silica white.
In the step 2), the solvent S2 is at least one selected from N, N-dimethylformamide, N-dimethylacetamide, N-diethylformamide and N, N-dibutylformamide; preferably, the solvent S2 is selected from at least one of N, N-dimethylformamide and N, N-dimethylacetamide.
In the method, the aluminum source, the phosphorus source and the silicon source are calculated by oxides, and the molar ratio of the used raw materials is as follows: SiO 22：Al2O3＝0.001～1，P2O5：Al2O30.5-1.5, mixing a template agent: al (Al)2O30.1 to 60 parts by weight of a solvent (S1+ S2): al (Al)2O31-500 parts of; preferably, SiO2：Al2O3＝0.01～0.5，P2O5：Al2O30.75-1.25, mixing a template agent: al (Al)2O30.5-30, solvent (S1+ S2): al (Al)2O310-150; more preferably, SiO2：Al2O3＝0.05～0.1，P2O5：Al2O30.95-1.05, mixing a template agent: al (Al)2O31-15, solvent (S1+ S2): al (Al)2O320-80. Further, the molar ratio of the template R1 to the template R2 in the mixed template is R1: r2 is 0.1-10: 1, the molar ratio of the solvent S2 to the solvent S1 is S2: s1 is 0.1-10: 1; preferably R1: r2 is 1.0-5.0: 1, S2: s1 is 0.75-2.5: 1.
in the method of the present invention, in the step 1), the aluminum source, the solvent S1, the phosphorus source, and the mixed template agent may be mixed by first mixing the aluminum source with the solvent S1, and then adding the phosphorus source and the mixed template agent.
In the method, in the step 1), the mixing time is 0.5-5 h, and the settling time is 2-12 h.
In the method, in the step 2), the mixing time is 0.5-5 h, and the pretreatment conditions are as follows: treating for 2-12 h at 60-120 ℃.
In the method of the present invention, in the step 3), the crystallization reaction conditions of the crystallization mixture are as follows: crystallizing at 120-220 ℃ for 12-15 days, preferably crystallizing at 140-200 ℃ for 24-10 days; more preferably: crystallizing at 160-180 ℃ for 54 h-5 d.
In the method, in the step 3), the product after the crystallization reaction is subjected to post-treatment to obtain the SCM-29 zeolite molecular sieve, wherein the post-treatment comprises filtering, washing and drying, and the drying conditions are as follows: drying for 4-8 h at 80-120 ℃.
The SCM-29 molecular sieves provided by the present invention may be used in any physical form, such as a powder, a pellet, or a molded article (e.g., a bar, a clover, etc.). These physical forms can be obtained in any manner conventionally known in the art and are not particularly limited.
The invention also provides a molecular sieve composition, which comprises the SCM-29 molecular sieve or the SCM-29 molecular sieve prepared according to the preparation method of the SCM-29 molecular sieve. Other materials contained in the molecular sieve composition may be active and inactive materials. Other molecular sieves may be used as the active material, and clays, alumina, silica gel, etc., may be used as the inactive material (generally referred to as a binder). These other materials may be used singly or in combination of plural kinds in any ratio. As the amount of the other materials, those conventionally used in the art can be referred to, and there is no particular limitation.
The SCM-29 molecular sieve, the SCM-29 molecular sieve prepared by the preparation method of the SCM-29 molecular sieve or the molecular sieve composition can be used as a catalyst. The SCM-29 molecular sieve is used as a catalyst (or as a catalytic active component thereof) directly or after being subjected to conventional treatment (such as ion exchange and the like) in the field, and can be a catalyst for preparing hydrocarbon from methanol.
The SCM-29 molecular sieve is applied to the reaction for preparing the hydrocarbon from the methanol, and the reaction conditions can be as follows: methanol is used as a raw material, the reaction temperature is 450-550 ℃, the reaction pressure is 0.1-10 MPa, and the weight space velocity of the methanol is 0.1-10 h-1。
When the SCM-29 molecular sieve prepared by the invention is applied to the reaction of preparing hydrocarbon from methanol, the conversion rate of the methanol reaches 100 percent, the one-way selectivity of ethylene and propylene can reach 76.8 percent, and the catalyst has good stability within the set evaluation condition range.
Drawings
Figure 1 is an XRD diffraction pattern of the SCM-29 molecular sieve synthesized in example 1.
Detailed Description
The present invention is further illustrated by the following examples, but it should be understood that the scope of the present invention is not limited by the examples. In the present invention, percentages and percentages are by mass unless otherwise specifically indicated.
In the invention, the crystal phase of the product is measured by an X' Pert PRO type X-ray powder diffraction (XRD) instrument of Pynaudiaceae, Netherlands, the incident ray of X-ray diffraction is Cu Ka 1, the working voltage is 40kV, the current is 40mA, and the scanning range is 5-50 degrees.
[ example 1 ]
Dissolving 6.8g of aluminum nitrate in 5.4mL of deionized water, mixing to form a solution A, adding 2.16g of phosphoric acid (85 wt.% aqueous solution), 8.1g of cyclohexylamine and 7.5g of tetraethylammonium hydroxide (50 wt.% aqueous solution) into the solution A, stirring for 5 hours, precipitating for 2 hours to obtain a solution A ', slowly adding 0.14g of acidic silica sol (60 wt.% aqueous solution) and 30.1mL of N, N-dimethylformamide into the solution A', stirring for 5 hours, then placing at 60 ℃ for heat treatment for 12 hours to form a uniform crystallized mixture, placing the crystallized mixture at 160 ℃ for crystallization for 5 days, filtering and washing the product, and drying at 80 ℃ for 8 hours to obtain a product SCM-29, wherein the X-ray diffraction pattern of the product is shown in Table 1.
TABLE 1
[ example 2 ]
201.88g of aluminum sulfate is dissolved in 330.4mL of water and mixed to form a solution A, then 37.7g of ammonium monohydrogen phosphate, 260.39g of cyclohexylamine and 322.5g of tetraethylammonium hydroxide (50 wt.% aqueous solution) are added into the solution A, stirred for 0.5h and precipitated for 12h to obtain a solution A ', then 1.78g of white carbon black and 1497.2mL of N, N-dimethylformamide are slowly added into the solution A ', the solution A ' is stirred for 0.5h and then is heated at 120 ℃ for 2h to form a uniform crystallization mixture, the crystallization mixture is placed at 180 ℃ for crystallization for 54h, and the product is filtered and washed and then dried at 120 ℃ for 4h to obtain the SCM-29 product, wherein the X-ray diffraction line of the product is shown in Table 2.
TABLE 2
[ example 3 ]
2121.33g of aluminum sulfate is mixed in 1196.8mL of water to form a solution A, then 733.2g of phosphoric acid (85 wt.% aqueous solution), 2222.7g of cyclohexylamine and 7471.8g of tetraethylammonium hydroxide (50 wt.% aqueous solution) are added to the solution A, stirred for 3.3h and precipitated for 4h to obtain a solution A ', then 79.9g of acidic silica sol (40 wt.% aqueous solution) and 45858.2mL of N, N-dimethylformamide are slowly added to the solution A', stirred for 2.5h and then placed at 100 ℃ for heat treatment for 7h to form a uniform crystallization mixture, the crystallization mixture is placed at 175 ℃ for crystallization for 78h, and the product is filtered, washed and dried at 90 ℃ for 7h to obtain the product SCM-29, wherein the X-ray line is shown in Table 3.
TABLE 3
[ example 4 ]
36.39g of aluminum nitrate is dissolved in 49.3mL of water and mixed to form a solution A, 22.1g of phosphoric acid (85 wt.% aqueous solution), 85.4g of cyclohexylamine and 212.1g of tetraethylammonium hydroxide (60 wt.% aqueous solution) are added into the solution A, the solution A 'is stirred for 2.3h and precipitated for 6h to form a solution A', 1.5g of acidic silica sol (50 wt.% aqueous solution) and 498.8mL of N, N-dimethylformamide are slowly added into the solution A ', the solution A' is stirred for 4.1h and then is heated at 110 ℃ for 3h to form a uniform crystallization mixture, the crystallization mixture is placed at 170 ℃ for crystallization for 4d, and the product is filtered and washed and dried at 130 ℃ for 4h to form the product SCM-29, wherein the X-ray diffraction line of the product is shown in Table 4.
TABLE 4
[ example 5 ]
10339.9g of aluminum sulfate is dissolved in 4102.6g of water and mixed to form a solution A, then 3685.1g of phosphoric acid (85 wt.% aqueous solution), 8848.8g of cyclohexylamine and 13859.7g of tetraethylammonium bromide are added into the solution A, stirred for 1.5h and precipitated for 8h to obtain a solution A ', 111.8g of white carbon black and 37799.7mL of N, N-dimethylformamide are slowly added into the solution A', stirred for 2.2h and then heated at 70 ℃ for 9h to form a uniform crystallization mixture, the crystallization mixture is placed at 170 ℃ for crystallization for 3d, and the product is filtered, washed and dried at 100 ℃ for 8h to obtain the product SCM-29, wherein the X-ray diffraction line of the product is shown in Table 5.
TABLE 5
[ examples 6 to 10 ] to provide a toner
SCM-29 molecular sieves were synthesized according to the procedure of example 5, using the starting materials shown in Table 6, and controlling the reaction materials in different ratios (Table 7).
TABLE 6
TABLE 7
Examples
Reactant proportioning composition
R1/R2
S2/S1
Product of
Example 6
Al2O3：SiO2：P2O5：R：S＝1：0.08：0.96：6：80
2.7
1.5
SCM-29
Example 7
Al2O3：SiO2：P2O5：R：S＝1：0.1：0.95：3：38
5.0
2.5
SCM-29
Example 8
Al2O3：SiO2：P2O5：R：S＝1：0.07：0.98：15：59
1.5
0.75
SCM-29
Example 9
Al2O3：SiO2：P2O5：R：S＝1：0.05：1.05：9：20
1.0
1.0
SCM-29
Example 10
Al2O3：SiO2：P2O5：R：S＝1：0.09：0.97：2：49
3.5
2.0
SCM-29
[ example 11 ]
Application of SCM-29 molecular sieve in methanol-to-hydrocarbon reaction
And (3) roasting the SCM-29 molecular sieve synthesized in the embodiment 9 at 550 ℃ for 4 hours, cooling to room temperature, tabletting, breaking, and screening to obtain particles of 12-20 meshes for later use. Methanol is used as raw material, a fixed bed reactor with the diameter of 15 mm is used, the temperature is 460 ℃, the mass space velocity is 2.0h-1And the evaluation is carried out under the condition that the pressure is 1.5MPa, the conversion rate of the methanol is 100 percent, the selectivity of the ethylene and the propylene reaches 76.8 percent, and a better technical effect is achieved.