CN112573535B

CN112573535B - SCM-32 molecular sieve and preparation method and application thereof

Info

Publication number: CN112573535B
Application number: CN201910932975.0A
Authority: CN
Inventors: 杨为民; 刘闯; 王振东; 李相呈; 罗翼; 梁俊
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Priority date: 2019-09-29
Filing date: 2019-09-29
Publication date: 2022-07-12
Anticipated expiration: 2039-09-29
Also published as: CN112573535A

Abstract

The invention discloses an SCM-32 molecular sieve and a preparation method and application thereof. The SCM-32 molecular sieve has the formula of mSiO₂·nAl₂O₃"schematic chemical composition shown; wherein: m/n is more than or equal to 10 and less than or equal to 29, the molecular sieve is a novel molecular sieve with an MRE structure, has a unique chemical composition, and shows excellent performance as a catalyst.

Description

SCM-32 molecular sieve, and preparation method and application thereof

Technical Field

The invention relates to a novel molecular sieve, in particular to an SCM-32 molecular sieve and a preparation method and application thereof.

Background

In industry, molecular sieve materials are widely used in the fields of catalysis, ion exchange, adsorption, and separation due to their open structure and large surface area. These subtle differences in the structure of the materials are predictive of differences in the various observable properties that characterize them, such as their morphology, specific surface area, void size and variability in these dimensions, and also mean that they may themselves differ greatly in the catalytic and adsorptive properties of the materials.

The MRE type molecular sieve is an orthorhombic or pseudo orthorhombic symmetrical molecular sieve with deca-ring non-interconnected linear channels, with a pore size of 0.53nm x 0.56 nm. The MRE type molecular sieve can be widely applied to catalytic reactions of hydrocarbon conversion, such as aromatic alkylation, isomerization, disproportionation, methanol conversion and the like; the pure silicon MRE type molecular sieve has good low-carbon olefin selectivity in the reaction of preparing olefin from synthesis gas, and the MRE type molecular sieve with low silicon-aluminum ratio has good catalytic performance.

US4423021 discloses a synthesis of ZSM-48(MRE structure) zeolite, which comprises: an organic diamine compound containing 4-12 carbon atoms is used as an organic structure directing agent, a mixture of a silicon dioxide source, an alkali metal source, water and the organic structure directing agent is formed according to a certain proportion, the mixture reacts for 2-3 days at 160 ℃, and a product ZSM-48 molecular sieve crystal is prepared through cooling, filtering and washing with water, but the ZSM-48 molecular sieve synthesized by the method does not contain aluminum, so that almost no acidity exists.

US7482300 and US7625478 disclose a method for preparing ZSM-48, in which a costly organic structure directing agent, hexamethodiamine chloride, is used to obtain a ZSM-48 molecular sieve having a silica-alumina ratio of about 100; CN101330976B discloses a preparation method of high-activity ZSM-48, which adopts an organic structure directing agent of hexamethonium salt to obtain a ZSM-48 molecular sieve with the silicon-aluminum ratio of 70-110; CN103803576B discloses a ZSM-48 molecular sieve with a low silica-alumina ratio and a preparation method thereof, wherein 12-crown ether-4 is adopted as a template agent, and the silica-alumina ratio of the obtained ZSM-48 molecular sieve is basically 33-50.

The ZSM-48 molecular sieve with high silica-alumina ratio contains less acid, so the wide application of the ZSM-48 molecular sieve in catalytic reaction is limited, and the bottleneck limiting the wide application of the ZSM-48 molecular sieve can be broken only by improving the synthesis method to prepare the ZSM-48 molecular sieve with low silica-alumina ratio and improve the acid content of the unit molecular sieve.

The specific structure of a molecular sieve is determined by X-ray diffraction pattern (XRD), which is different from zeolite molecular sieves in XRD pattern characteristics. The existing molecular sieves, such as A-type zeolite, Y-type zeolite, MCM-22 molecular sieve and the like, have XRD spectrums with respective characteristics. Meanwhile, the molecular sieve has the same XRD spectrogram characteristics, but different types of framework elements and different molecular sieves. Such as TS-1 molecular sieve (US4410501) and ZSM-5 molecular sieve (US3702886), which have the same XRD spectrum characteristics but different framework elements. Specifically, the TS-1 molecular sieve has a catalytic oxidation function due to the framework elements of Si and Ti, and the ZSM-5 molecular sieve has an acid catalytic function due to the framework elements of Si and Al. In addition, the molecular sieve has the same XRD spectrogram characteristics, the types of the framework elements are also the same, but the relative contents of the framework elements are different, and the molecular sieve belongs to different molecular sieves. Such as X zeolite (US2882244) and Y zeolite (US3130007), both having the same XRD spectrum characteristics, with both framework elements Si and Al, but with different relative contents of Si and Al. In particular, the Si/Al molar ratio of the X zeolite is lower than 1.5, while the Si/Al molar ratio of the Y zeolite is higher than 1.5.

Disclosure of Invention

The invention provides an SCM-32 molecular sieve and a preparation method and application thereof. The molecular sieve is a novel molecular sieve with an MRE structure, has a unique chemical composition, and shows excellent performance as a catalyst.

In one aspect, the invention provides an SCM-32 molecular sieve, wherein the SCM-32 molecular sieve has a formula of mSiO₂·nAl₂O₃"schematic chemical composition shown; wherein: 10 m/n 29, preferably 10 m/n 25, the SCM-32 molecular sieve has an X-ray diffraction pattern shown in the following table,

a: ± 0.30 °, b: as a function of 2 theta.

Further, the X-ray diffraction pattern of the SCM-32 molecular sieve also comprises X-ray diffraction peaks shown in the following table,

a: ± 0.30 °, b: as a function of 2 theta.

In the invention, the specific surface area of the SCM-32 molecular sieve is 300-700 m²Per gram, preferably 350 to 650 m²Per gram, more preferably 400 to 550 m²Per gram; the micro-pore volume of the SCM-32 molecular sieve is 0.05-0.40 cmRice and its production process³Per gram, preferably 0.08-0.35 cm³A/g, more preferably 0.10 to 0.30 cm³Per gram, more preferably 0.12 to 0.23 cm³Per gram.

In the invention, the number of the channel rings of the SCM-32 molecular sieve is between eight-membered rings and fourteen-membered rings, preferably between ten-membered rings and twelve-membered rings; the pore diameter is 0.40 to 0.75 nm, preferably 0.50 to 0.65 nm.

In a second aspect, the present invention provides a method for preparing the SCM-32 molecular sieve, which comprises: mixing a silicon source, an aluminum source, hydrofluoric acid, an organic structure directing agent (R) and water, and then carrying out crystallization reaction to obtain the SCM-32 molecular sieve.

The organic structure directing agent is selected from a compound of the following structural formula (A), a quaternary ammonium salt thereof or a quaternary ammonium base form thereof,

wherein R is₁And R₂Each independently selected from C_1-8Alkyl, preferably selected from C_1-4Alkyl, more preferably selected from C_1-2An alkyl group.

The organic structure directing agent is preferably 4-dimethylaminopyridine.

The silicon source is at least one of silicic acid, silica gel, silica sol, tetraethyl silicate and water glass; the aluminum source is at least one selected from the group consisting of aluminum hydroxide, aluminum oxide, aluminates, aluminum salts, and tetraalkoxyaluminum.

As the quaternary ammonium salt form of the compound of the formula (A), for example, there may be mentioned compounds having N atoms other than R₁And R₂In addition, a C is additionally combined_1-8Alkyl (preferably C)_1-4Alkyl, more preferably C_1-2Alkyl or methyl) to obtain quaternary nitrogen (N)⁺) And (5) structure. As the counter anion of the quaternary nitrogen structure, for example, a halogen ion such as Br can be mentioned^-Or Cl^-And the like, but are not limited thereto in some cases.

As quaternary ammonium base forms of the compounds of the formula (A), mention may be made, for exampleTo cite the addition of a C to the N atom in addition to R1 and R2_1-8Alkyl (preferably C)_1-4Alkyl, more preferably C_1-2Alkyl or methyl) to obtain quaternary nitrogen (N)⁺) The counter anion of the quaternary nitrogen structure is a hydroxide ion (OH)^-)。

The silicon source is SiO₂Calculated as Al) and an aluminum source (calculated as Al)₂O₃By weight) are as follows: 1 (0.026-0.1), preferably 1 (0.027-0.08), more preferably 1 (0.03-0.06).

The silicon source is SiO₂The molar ratio of the hydrofluoric acid (counted as F), the organic structure directing agent (R) and the water is 1 (0.05-1.0) (5-60), preferably 1 (0.08-0.9) (6-55), more preferably 1 (0.15-0.8) (0.12-0.8) (8-50).

The crystallization reaction is performed under the conditions of crystallization at 120-200 ℃ for 1-20 days, preferably at 120-180 ℃ for 2-18 days, and more preferably at 135-180 ℃ for 5-16 days.

After the crystallization reaction is finished, carrying out conventional post-treatment, such as filtering, washing and drying to obtain the molecular sieve; and optionally, a step of calcining the obtained molecular sieve.

The filtration, washing and drying may be performed in any manner conventionally known in the art. As a specific example, as the filtration, for example, the obtained product mixture may be simply filtered with suction. Examples of the washing include washing with deionized water. The drying conditions are as follows: drying for 8-30 h at 40-250 ℃, preferably: drying at 60-150 ℃ for 10-20 h, wherein the drying can be carried out under normal pressure or under reduced pressure; the roasting conditions are as follows: roasting for 1-12 h at 300-950 ℃, preferably: roasting for 2-10 h at 350-900 ℃; the calcination is generally carried out in an oxygen-containing atmosphere, such as air or oxygen.

The material added in the preparation method of the SCM-32 molecular sieve does not contain an alkali source. Examples of the alkali source include alkaline substances other than a silica source, an alumina source and an organic structure-directing agent, and specific examples thereof include any alkali source conventionally used in the art for the purpose of making the system alkaline, and more specific examples thereof include inorganic bases having an alkali metal or an alkaline earth metal as a cation, and in particular, sodium hydroxide, potassium hydroxide and the like. Herein, "not including an alkali source" means that an alkali source is not intentionally or actively introduced into the mixture.

In the present invention, the SCM-32 molecular sieve may be present in an unfired state (synthesized state) or in a calcined state. When present in the as-synthesized state, the SCM-32 molecular sieve generally has a schematic chemical composition as represented by the formula "oxide-organic structure directing agent-water". In the case of being present in the as-synthesized state, it is known that molecular sieves sometimes (particularly immediately after synthesis) contain some amount of moisture, but the presence or absence of moisture does not substantially affect the XRD patterns of the molecular sieves.

In the present invention, in a schematic chemical composition represented by the formula "oxide/organic structure directing agent/water", the molar ratio of the organic structure directing agent to the oxide is 0.01 to 2.0, preferably 0.03 to 0.40, more preferably 0.05 to 0.33, more preferably 0.06 to 0.30, more preferably 0.07 to 0.21; the mass ratio of the water to the oxide is 0 to 0.17, preferably 0.02 to 0.12.

In the method for synthesizing the molecular sieve, the oxide is a combination of a silica source and an alumina source.

In the present invention, the SCM-32 molecular sieve described previously 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.

In another aspect of the invention, the SCM-32 molecular sieve may be used in combination with other materials to obtain a SCM-32 molecular sieve composition. Examples of the other materials include active materials and inactive materials. Examples of the active material include synthetic zeolite, natural zeolite, and other types of molecular sieves, and examples of the inactive material (generally referred to as a binder) include clay, silica gel, and alumina. These other materials may be used singly or in combination in any ratio. As the amount of the other materials, those conventionally used in the art can be directly referred to, and there is no particular limitation.

In another aspect of the invention, the use of the SCM-32 molecular sieve, SCM-32 molecular sieve composition according to any of the preceding aspects, as an adsorbent or catalyst for the conversion of organic compounds.

The SCM-32 molecular sieve or molecular sieve composition is used as an adsorbent, for example, to separate at least one component from a mixture of components in a gas or liquid phase. Accordingly, the at least one component may be partially or substantially completely separated from the mixture of components, such as by contacting the mixture with the SCM-32 molecular sieve or the molecular sieve composition to selectively adsorb such component.

The SCM-32 molecular sieve or the molecular sieve composition can be used as an alkane isomerization reaction catalyst, an aromatic hydrocarbon and olefin alkylation reaction catalyst, an olefin isomerization reaction catalyst, a naphtha cracking reaction catalyst, an aromatic hydrocarbon and alcohol alkylation reaction catalyst, an olefin hydration reaction catalyst, an alcohol-to-olefin reaction catalyst and an aromatic hydrocarbon disproportionation reaction catalyst after being roasted.

According to the invention, the SCM-32 silicon-aluminum molecular sieve has an MRE structure, the silicon-aluminum ratio of the molecular sieve is low, the chemical composition of the molecular sieve is never obtained before in the field, and the molecular sieve has excellent catalytic performance.

In the preparation method, aminopyridine is used as an organic structure directing agent, an MRE type molecular sieve is obtained without adding an alkali source in the reaction process, and the obtained molecular sieve can be used as a catalyst without ammonium ion exchange. The method is simple, the raw materials are cheap, the method is suitable for large-scale industrial production, and a good technical effect is achieved.

Drawings

FIG. 1 is an X-ray diffraction pattern (XRD) of the molecular sieve obtained in example 1;

FIG. 2 is an X-ray diffraction pattern (XRD) of the molecular sieve obtained in example 2.

Detailed Description

The following detailed description of the embodiments of the present invention is provided, but it should be noted that the scope of the present invention is not limited by the embodiments.

All publications, patent applications, patents, and other references mentioned in this specification are herein incorporated by reference in their entirety. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present specification, including definitions, will control.

When the specification concludes with claims with the heading "known to those skilled in the art", "prior art", or the like, to derive materials, substances, methods, procedures, devices, or components, etc., it is intended that the subject matter derived from the heading encompass those conventionally used in the art at the time of filing this application, but also include those that are not currently in use, but would become known in the art to be suitable for a similar purpose.

In the context of the present specification, anything or things which are not mentioned, except where explicitly stated, are directly applicable to those known in the art without any changes. Moreover, any embodiment described herein may be freely combined with one or more other embodiments described herein, and the technical solutions or concepts resulting therefrom are considered part of the original disclosure or original disclosure of the invention, and should not be considered as new matters not disclosed or contemplated herein, unless a person skilled in the art would consider such a combination to be clearly unreasonable.

In the context of the present specification, a molecular sieve is referred to as a "precursor" before substances (such as organic structure directing agent molecules and the like) filled in the channels when the molecular sieve is synthesized, other than water and metal ions, in the channels of the molecular sieve are not removed.

In the context of this specification, in the XRD data of molecular sieves, w, m, s, vs represent diffraction peak intensities, w is weak, m is medium, s is strong, vs is very strong, as is well known to those skilled in the art. Generally, w is less than 20; m is 20 to 40; s is 40-70; vs is greater than 70.

In the context of the present specification, the structure of a molecular sieve is determined by X-ray diffraction pattern (XRD), which is determined by X-ray powder diffractometry using a Cu-ka radiation source, a nickel filter. Before the sample is tested, a Scanning Electron Microscope (SEM) is adopted to observe the crystallization condition of the molecular sieve sample, the sample is confirmed to contain only one crystal, namely the molecular sieve sample is a pure phase, and then XRD test is carried out on the basis, so that no interference peak of other crystals exists in a diffraction peak in an XRD spectrogram. Wherein the X-ray powder diffractometer is a Panalytical X PERPRO type X-ray powder diffractometer, and the Scanning Electron Microscope (SEM) is a S-4800II type field emission scanning electron microscope.

Example 1

5.790 g of deionized water, 2.618 g of organic structure directing agent 4-dimethylaminopyridine, 5.364 g of silica sol (containing SiO)₂40 percent by weight), 0.312 g of aluminum hydroxide and 1.072 g of hydrofluoric acid (containing 40 percent by weight of HF) are evenly mixed to prepare a mixture, and the material ratio (molar ratio) of reactants is as follows:

Al₂O₃/SiO₂＝0.056

4-dimethylaminopyridine/SiO₂＝0.6

F/SiO₂＝0.6

H₂O/SiO₂＝15

After being mixed evenly, the mixture is put into a stainless steel reaction kettle and crystallized for 15 days at 170 ℃. Filtering, washing, drying in a 110 deg.C oven for 12 hr to obtain molecular sieve, wherein the XRD spectrogram data of the obtained molecular sieve is shown in Table 1, and the XRD spectrogram is shown in FIG. 1;

TABLE 1

The specific surface area of the obtained molecular sieve product is405 m²G, micropore volume of 0.12 cm³Per gram.

Measuring SiO of the obtained molecular sieve product by adopting inductively coupled plasma atomic emission spectrometry (ICP)₂/Al₂O₃16.8 (molar ratio).

Example 2

4.160 grams deionized water, 1.540 grams organic structure directing agent 4-dimethylaminopyridine, 9.464 grams silica sol (containing SiO)₂40 percent by weight), 0.5661 grams of aluminum hydroxide and 2.522 grams of hydrofluoric acid (containing 40 percent by weight of HF) are uniformly mixed to prepare a mixture, and the material ratio (molar ratio) of reactants is as follows:

Al₂O₃/SiO₂＝0.058

4-dimethylaminopyridine/SiO₂＝0.2

F/SiO₂＝0.8

H₂O/SiO₂＝15

After being mixed evenly, the mixture is put into a stainless steel reaction kettle and crystallized for 14 days at the temperature of 140 ℃. Filtering, washing, and drying in a 110 deg.C oven for 12 hr to obtain molecular sieve, wherein the XRD spectrogram data of the molecular sieve product is shown in Table 2, and the XRD spectrogram is shown in FIG. 2;

TABLE 2

The specific surface area of the obtained molecular sieve product is 407 m²G, micropore volume 0.15 cm³Per gram.

Measuring SiO of the obtained molecular sieve product by adopting inductively coupled plasma atomic emission spectrometry (ICP)₂/Al₂O₃17.5 (molar ratio).

Example 3

6.437 g of deionized water and 1.871 g of organic structure directing agent 4-dimethylamino pyrazinePyridine 9.202 g silica sol (containing SiO)₂40 percent by weight), 0.5162 grams of aluminum hydroxide and 2.145 grams of hydrofluoric acid (containing 40 percent by weight of HF) are uniformly mixed to prepare a mixture, and the material ratio (molar ratio) of reactants is as follows:

Al₂O₃/SiO₂＝0.054

4-dimethylaminopyridine/SiO₂＝0.25

F/SiO₂＝0.7

H₂O/SiO₂＝12

After being mixed evenly, the mixture is put into a stainless steel reaction kettle and crystallized for 13 days at the temperature of 150 ℃. Filtering and washing after crystallization, drying in a 110 ℃ oven for 12h to obtain the molecular sieve, wherein XRD spectrogram data of the obtained molecular sieve is shown in Table 3, and the XRD spectrogram is similar to that of figure 1;

TABLE 3

The specific surface area of the obtained molecular sieve product is 415 m²G, micropore volume 0.13 cm³Per gram.

Measuring SiO of the obtained molecular sieve product by adopting inductively coupled plasma atomic emission spectrometry (ICP)₂/Al₂O₃19.6 (molar ratio).

Example 4

12.416 g of deionized water, 2.091 g of organic structure directing agent 4-dimethylaminopyridine, 8.568 g of silica sol (containing SiO)₂40 percent by weight), 0.356 g of aluminum hydroxide and 1.569 g of hydrofluoric acid (containing 40 percent by weight of HF) are uniformly mixed to prepare a mixture, and the material ratio (molar ratio) of reactants is as follows:

Al₂O₃/SiO₂＝0.040

4-dimethylaminopyridine/SiO₂＝0.3

F/SiO₂＝0.55

H₂O/SiO₂＝18

After being mixed evenly, the mixture is put into a stainless steel reaction kettle and crystallized for 12 days at the temperature of 155 ℃. Filtering and washing after crystallization is finished, drying in a 110 ℃ oven for 12h to obtain the molecular sieve, wherein XRD spectrogram data of the obtained molecular sieve product is shown in table 4, and the XRD spectrogram is similar to that in figure 1;

TABLE 4

The specific surface area of the obtained molecular sieve product is 412 m²G, micropore volume 0.14 cm³Per gram.

Measuring SiO of the obtained molecular sieve product by adopting inductively coupled plasma atomic emission spectrometry (ICP)₂/Al₂O₃24.9 (molar ratio).

Example 5

18.607 g of deionized water, 3.118 g of organic structure directing agent 4-dimethylaminopyridine, 10.951 g of silica sol (containing SiO)₂40 percent by weight), 0.500 g of aluminum hydroxide and 1.824 g of hydrofluoric acid (containing 40 percent by weight of HF) are uniformly mixed to prepare a mixture, and the material ratio (molar ratio) of reactants is as follows:

Al₂O₃/SiO₂＝0.044

4-dimethylaminopyridine/SiO₂＝0.35

F/SiO₂＝0.5

H₂O/SiO₂＝20

After being mixed evenly, the mixture is put into a stainless steel reaction kettle and crystallized for 11 days at 160 ℃. Filtering and washing after crystallization is finished, drying in a 110 ℃ oven for 12h to obtain the molecular sieve, wherein the XRD spectrogram data of the molecular sieve product is shown in Table 5, and the XRD spectrogram is similar to that in figure 1;

TABLE 5

The specific surface area of the obtained molecular sieve product is 425 m²G, micropore volume of 0.16 cm³Per gram

Measuring SiO of the obtained molecular sieve product by adopting inductively coupled plasma atomic emission spectrometry (ICP)₂/Al₂O₃23.3 (molar ratio).

Example 6

27.271 g of deionized water, 3.827 g of organic structure directing agent 4-dimethylaminopyridine, 11.761 g of silica sol (containing SiO)₂40 percent by weight), 0.574 g of aluminum hydroxide and 1.567 g of hydrofluoric acid (containing 40 percent by weight of HF) are uniformly mixed to prepare a mixture, and the material ratio (molar ratio) of reactants is as follows:

Al₂O₃/SiO₂＝0.047

4-dimethylaminopyridine/SiO₂＝0.4

F/SiO₂＝0.4

H₂O/SiO₂＝25

After being mixed evenly, the mixture is put into a stainless steel reaction kettle and crystallized for 10 days at 165 ℃. Filtering, washing, drying in 110 deg.C oven for 12 hr to obtain molecular sieve, and XRD spectrogram data of the obtained molecular sieve is shown in Table 6, and XRD spectrogram is similar to that in FIG. 1;

TABLE 6

The specific surface area of the obtained molecular sieve product is 418 m²G, micropore volume 0.13 cm³Per gram.

Using inductively coupled plasma atomic emissionMeasuring SiO of the obtained molecular sieve product by using an optical spectrum (ICP)₂/Al₂O₃21.8 (molar ratio).

Example 7

39.206 g of deionized water, 5.426 g of organic structure directing agent 4-dimethylaminopyridine, 13.342 g of silica sol (containing SiO)₂40 percent by weight), 0.693 g of aluminum hydroxide and 1.333 g of hydrofluoric acid (containing 40 percent by weight of HF) are uniformly mixed to prepare a mixture, and the material ratio (molar ratio) of reactants is as follows:

Al₂O₃/SiO₂＝0.050

4-dimethylaminopyridine/SiO₂＝0.5

F/SiO₂＝0.3

H₂O/SiO₂＝30

After being mixed evenly, the mixture is put into a stainless steel reaction kettle and crystallized for 9 days at 175 ℃. Filtering and washing after crystallization is finished, drying in a 110 ℃ oven for 12h to obtain the molecular sieve, wherein XRD spectrogram data of the obtained molecular sieve product is shown in Table 7, and the XRD spectrogram is similar to that in figure 1;

TABLE 7

The specific surface area of the obtained molecular sieve product is 409 m²G, micropore volume 0.14 cm³Per gram.

Measuring SiO of the obtained molecular sieve product by adopting inductively coupled plasma atomic emission spectrometry (ICP)₂/Al₂O₃20.9 (molar ratio).

Example 8

55.722 g of deionized water, 3.831 g of organic structure directing agent 4-dimethylaminopyridine, 13.458 g of silica sol (containing SiO)₂40 percent by weight), 0.769 g of aluminum hydroxide and 1.121 g of hydrofluoric acid (containing 40 percent by weight of HF) are uniformly mixed to prepare a mixture, and the material ratio (molar ratio) of reactants is as follows:

Al₂O₃/SiO₂＝0.055

4-dimethylamino pyrazinepyridine/SiO₂＝0.35

F/SiO₂＝0.25

H₂ O/SiO₂＝40

After being mixed evenly, the mixture is put into a stainless steel reaction kettle and crystallized for 7 days at 180 ℃. Filtering and washing after crystallization, drying in a 110 ℃ oven for 12h to obtain a molecular sieve, wherein XRD spectrogram data of the sample is shown in Table 8, and the XRD spectrogram is similar to that in figure 1;

TABLE 8

The specific surface area of the obtained molecular sieve product is 422 m²G, micropore volume 0.15 cm³And (c) grams.

Measuring SiO of the obtained molecular sieve product by adopting inductively coupled plasma atomic emission spectrometry (ICP)₂/Al₂O₃20.6 (molar ratio).

Example 9

The same as example 2 except that the alumina source was aluminum isopropoxide.

After being mixed evenly, the mixture is put into a stainless steel reaction kettle and crystallized for 15 days at 170 ℃. Filtering and washing after crystallization, drying in a 110 ℃ oven for 12h to obtain a molecular sieve, wherein XRD spectrogram data of the sample is shown in Table 9, and the XRD spectrogram is similar to that of figure 1;

TABLE 9

The specific surface area of the obtained molecular sieve product is 410 m²G, micropore volume 0.15 cm³Per gram.

Example 10

Taking 1.5 g of a calcined powder sample synthesized in example 5, crushing, screening a 20-40 mesh part, putting the part into a fixed bed reactor, reacting at 460 ℃, under normal pressure and at 6h of methanol weight space velocity^-1Is evaluated under the condition of (1). The product is analyzed by adopting an Shimadzu GC-2014 gas chromatograph, the methanol conversion rate is more than 98 percent, and the one-way yield of the ethylene, the propylene and the butylene which are the reaction products can reach 74.67 percent at most.

Example 11

Taking 1.0 g of the powder sample synthesized in the example 6 and roasted, crushing, screening a 20-40 mesh part, putting the part into a fixed bed reactor, reacting at 400 ℃ and normal pressure, wherein the molar ratio of the toluene and the methanol is 2:1, and the weight space velocity of the toluene is 2.0h^-1Is evaluated under the condition of (1). The product is analyzed by adopting an Shimadzu GC-2014 gas chromatograph, the conversion rate of toluene is more than 25 percent, the conversion rate of methanol is more than 98 percent, and the selectivity of the product xylene of the reaction can reach 82.5 percent at most.

Claims

1. An SCM-32 molecular sieve, the SCM-32 molecular sieve having the formula "mSiO₂·nAl₂O₃"schematic chemical composition shown; wherein: m/n is more than or equal to 10 and less than or equal to 29, the SCM-32 molecular sieve has an X-ray diffraction pattern shown in the following table,

a: ± 0.30 °, b: as a function of 2 theta.

2. An SCM-32 molecular sieve according to claim 1, characterized in that: m/n is more than or equal to 10 and less than 25.

3. The SCM-32 molecular sieve of claim 1, wherein: the SCM-32 molecular sieve also included X-ray diffraction peaks as shown in the following table,

a: ± 0.30 °, b: as a function of 2 theta.

4. A SCM-32 molecular sieve according to any of claims 1 to 3, characterized in that: the specific surface area of the SCM-32 molecular sieve is 300-700 m²Per gram; the micro-pore volume of the SCM-32 molecular sieve is 0.05-0.40 cm³Per gram.

5. The SCM-32 molecular sieve of claim 4, wherein: the specific surface area of the SCM-32 molecular sieve is 350-650 m²Per gram; the micro-pore volume of the SCM-32 molecular sieve is 0.08-0.35 cm³Per gram.

6. The SCM-32 molecular sieve of claim 4, wherein: the specific surface area of the SCM-32 molecular sieve is 400-550 m²Per gram; the micro-pore volume of the SCM-32 molecular sieve is 0.10-0.30 cm³Per gram.

7. The SCM-32 molecular sieve of claim 4, wherein: the micro-pore volume of the SCM-32 molecular sieve is 0.12-0.23 cm³Per gram.

8. A process for the preparation of the SCM-32 molecular sieve as claimed in any of claims 1 to 7: the method comprises the following steps: mixing a silicon source, an aluminum source, hydrofluoric acid, an organic structure directing agent and water, and then carrying out crystallization reaction to obtain the SCM-32 molecular sieve; the organic structure directing agent is selected from a compound of the formula, a quaternary ammonium salt thereof, or a quaternary ammonium base form thereof,

wherein R is₁And R₂Each independently selected from C_1-8An alkyl group.

9. The method of claim 8, wherein: r₁And R₂Each independently selected from C_1-4An alkyl group.

10. The method of claim 8, wherein: r₁And R₂Each independently selected from C_1-2An alkyl group.

11. The method of claim 8, wherein: the organic structure directing agent is 4-dimethylaminopyridine.

12. The method of claim 8, wherein: the silicon source is at least one of silicic acid, silica gel, silica sol, tetraethyl silicate and water glass; the aluminum source is at least one selected from the group consisting of aluminum hydroxide, aluminum oxide, aluminates, aluminum salts, and tetraalkoxyaluminum.

13. The method of claim 8, wherein: the silicon source is SiO₂Calculated as Al, and an aluminum source₂O₃The molar ratio is as follows: 1, (0.026-0.1); the silicon source is made of SiO₂The molar ratio of the organic structure directing agent to the water is 1 (0.05-1.0) to (5-60) in terms of F.

14. The method of claim 13, wherein: the silicon source is made of SiO₂Calculated as Al, and an aluminum source₂O₃The molar ratio is 1 (0.027-0.08); the silicon source is SiO₂The molar ratio of the organic structure directing agent to the water is 1 (0.08-0.9) to (6-55) in terms of F.

15. The method of claim 13, wherein: the silicon source is made of SiO₂Calculated as Al, and an aluminum source₂O₃The molar ratio is as follows: 1, (0.03-0.06); the silicon source is SiO₂The molar ratio of the organic structure directing agent to the water is 1 (0.15-0.8) to (0.12-0.8) to (8-50) in terms of F.

16. The method of claim 8, wherein: the crystallization reaction is performed for 1 to 20 days at a temperature of between 120 and 200 ℃.

17. The method of claim 16, wherein: the crystallization reaction is performed for 2-18 days at the temperature of 120-180 ℃.

18. The method of claim 16, wherein: the crystallization reaction is performed for 5-16 days at 135-180 ℃.

19. A molecular sieve composition comprising the SCM-32 molecular sieve of any of claims 1-7 or prepared according to the process for the preparation of the SCM-32 molecular sieve of any of claims 8-18, and a binder.

20. Use of the SCM-32 molecular sieve as defined in any of claims 1 to 7, the SCM-32 molecular sieve prepared by the process for its preparation as defined in any of claims 8 to 18, or the molecular sieve composition as defined in claim 19 as an adsorbent or catalyst for the conversion of organic compounds.