Silicon-aluminum molecular sieve SCM-36, its manufacturing method and use

Abstract

The present invention relates to a silicon-aluminum molecular sieve, SCM-36 zeolite, its preparation method and its use. The silicon / aluminum ratio n of the molecular sieve is ≧5, and the molecular sieve has a unique XRD diffraction spectrum. The SCM-36 molecular sieve is a novel molecular sieve and can be used as an adsorbent, catalyst, or catalyst support.

Description

Detailed Description of the Invention

[0001] [Technical Field] The present invention relates to the technical field of zeolites, in particular to silicon-aluminum zeolites, their preparation method and applications.

[0002] [Background technology] In industry, zeolite materials are widely used in areas such as catalysis, ion exchange, adsorption, and separation due to their hollow structure and large surface area. Subtle differences in the structure of these materials reveal differences in various observable properties used to characterize them, such as their morphology, specific surface area, pore size, and the variability of these sizes. These differences, in turn, suggest significant differences in the catalytic and adsorption properties of the materials themselves.

[0003] The basic framework structure of crystalline microporous zeolites is based on a rigid three-dimensional TO4 (SiO4, AlO4, etc.) unit structure. In this structure, TO4 shares oxygen atoms in tetrahedrons, and the charge balance of the framework tetrahedrons such as AlO4 is achieved by Na + and H + This is maintained by the presence of surface cations such as . Therefore, it is clear that the framework properties of zeolites can be modified by cation exchange. At the same time, the zeolite structure contains a rich system of pore channels with a certain pore size. These pore channels are interwoven to form a three-dimensional network structure, allowing the framework to remain stable even when water or organic matter in the pores is removed (US4439409). Based on the above structure, zeolites not only exhibit excellent catalytic activity and shape selectivity for various organic reactions, but also achieve good selectivity through modification (US6162416, US4954325, US5362697).

[0004] The specific structure of a zeolite can be determined by its X-ray diffraction spectrum (XRD) measured using an X-ray powder diffractometer equipped with a Cu-Kα X-ray source and a nickel filter. The characteristics of the X-ray diffraction spectrum vary depending on the zeolite. All known zeolites, such as A-type zeolite, Y-type zeolite, and MCM-22 zeolite, have their own characteristic XRD spectra.

[0005] On the other hand, zeolites with the same XRD spectral characteristics but different types of framework elements are also different zeolites. For example, TS-1 zeolite (US4410501) and ZSM-5 zeolite (US3702886) have the same XRD spectral characteristics but different framework elements. Specifically, the framework elements of TS-1 zeolite are Si and Ti, which have catalytic oxidation functions, while the framework elements of ZSM-5 zeolite are Si and Al, which have acid catalytic functions.

[0006] Furthermore, zeolites that have the same XRD spectral characteristics and the same types of framework elements but different relative contents of framework elements are different zeolites. For example, X zeolite (US 2,882,244) and Y zeolite (US 3,130,007) have the same XRD spectral characteristics and the same Si and Al framework elements, but different relative Si / Al contents. Specifically, the Si / Al molar ratio of X zeolite is lower than 1.5, while the Si / Al molar ratio of Y zeolite is higher than 1.5.

[0007] [Contents of the invention] The present application aims to provide a novel silicon-aluminum zeolite (referred to herein as SCM-36 zeolite), its preparation method, and its uses. The zeolite has specific XRD spectral characteristics and can be used as an adsorbent, catalyst support, and catalyst. When used as a catalyst in the reaction of 2,5-dimethylfuran and / or 2,5-hexanedione to produce p-xylene, it exhibits high selectivity for p-xylene and cyclic stability.

[0008] To achieve the above object, in one aspect, the present application provides a silicon-aluminum zeolite having a silicon / aluminum ratio n≧5, wherein the X-ray diffraction spectrum of this zeolite exhibits the relative intensity characteristics of the diffraction peaks as shown in the following table:

[0009] [Table 1]

[0010] In another aspect, the present application provides a method for producing a silicon-aluminum zeolite, comprising the steps of: 1) crystallizing a mixture containing a silicon source, an aluminum source, an organic structure directing agent (A), an organic structure directing agent (B), an alkali source, and water to obtain a zeolite; and 2) optionally calcining the zeolite obtained in step 1); Here, the organic structure-directing agent (A) is selected from tetramethylammonium compounds, and the organic structure-directing agent (B) is selected from C6-16 alkylpyridinium compounds, n-octyltrimethylammonium compounds, or a combination thereof.

[0011] In another aspect, there is provided a zeolite composition comprising a silicon-aluminum zeolite according to the present application and a binder.

[0012] In another aspect, there is provided the use of the present silicon-aluminum zeolite or zeolite composition as an adsorbent, catalyst or catalyst support.

[0013] In a further aspect, the present application provides a method for preparing p-xylene, the method comprising contacting and reacting a feedstock comprising 2,5-dimethylfuran, 2,5-hexanedione, or a combination thereof with ethylene in the presence of a catalyst comprising or consisting of a silicon-aluminum zeolite of the present application.

[0014] The present zeolite, which has a novel structure not reported in the prior art, can be used as an adsorbent, a catalyst support, or a catalyst. In particular, the present zeolite has high selectivity for p-xylene and cyclic stability when used as a catalyst in the reaction of 2,5-dimethylfuran and / or 2,5-hexanedione to prepare p-xylene.

[0015] BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the X-ray diffraction (XRD) spectrum of the zeolite obtained in Example I-1; FIG. 2 shows a scanning electron microscope (SEM) image of the zeolite obtained in Example I-1; FIG. 3 shows a transmission electron microscope (TEM) image of the zeolite obtained in Example I-1; FIG. 4 shows the ammonia temperature-programmed desorption (NH3-TPD) spectrum of the zeolite obtained in Example I-1; FIG. 5 shows the pyridine adsorption infrared (Py-FTIR) spectrum of the zeolite obtained in Example I-1; FIG. 6 shows the XRD spectrum of the zeolite obtained in Example I-2; FIG. 7 shows an SEM image of the zeolite obtained in Example I-3; Figure 8 shows the XRD spectrum of the sample obtained in Comparative Example I-1; Figure 9 shows the XRD spectrum of the sample obtained in Comparative Example I-3; Figure 10 shows the XRD spectrum of the sample obtained in Comparative Example I-4; FIG. 11 is a graph of 2,5-dimethylfuran conversion and p-xylene selectivity under recycle conditions for SCM-36 zeolite in Example II-15; Figure 12 shows the NH3-TPD spectrum of the zeolite obtained in Example II-16; FIG. 13 shows the Py-FTIR spectrum of the zeolite obtained in Example II-16. [Embodiments of the present invention] Specific embodiments of the present application will be described in detail below, but it should be noted that the scope of protection of the present application is not limited by these specific embodiments, but is determined by the appended claims.

[0016] All publications, patent applications, patents and other references mentioned in this specification are incorporated herein by reference.Unless otherwise defined, all technical and scientific terms used herein have the meanings that are commonly understood by those skilled in the art.In the event of any discrepancy, the definitions in this specification shall prevail.

[0017] When a material, substance, method, step, apparatus, or component is introduced with a modifier such as "known to those skilled in the art," "prior art," or similar terminology, the subject matter described by the modifier includes not only that which is commonly used in the art at the time of the filing of this application, but also those which are not currently in common use but which, as recognized in the art, become suitable for similar purposes.

[0018] In the context of this specification, unless explicitly stated, all unmentioned matters are directly applicable to what is known in the art without requiring modification. Furthermore, any embodiment described in this specification can be freely combined with one or more other embodiments described in this specification, and the resulting technical solutions or ideas shall be considered as part of the original disclosure or original description of this specification, but shall not be considered as new content not disclosed or anticipated in this specification, unless a person skilled in the art considers such a combination to be obviously unreasonable.

[0019] In the context of this specification, the so-called "silicon / aluminium ratio (or Si / Al ratio)" or "silicon / aluminium molar ratio (or Si / Al molar ratio)" refers to the ratio between the number of moles of silicon calculated on the basis of SiO2 in the zeolite and the number of moles of aluminium calculated on the basis of Al2O3 in the zeolite.

[0020] In the context of this specification, the term "calculated based on oxide" refers to a calculation based on the stable oxide of the corresponding element in its highest valence state. For example, in the expression "calculated based on oxide", silicon refers to a calculation based on SiO2, aluminum refers to a calculation based on Al2O3, titanium refers to a calculation based on TiO2, boron refers to a calculation based on B2O3, zirconium refers to a calculation based on ZrO2, tin refers to a calculation based on SnO2, and iron refers to a calculation based on Fe2O3.

[0021] In the context of this specification, with respect to zeolites, other materials, excluding water and metal ions (such as organic structure directing molecules), that are loaded into the pore channels during the synthesis of the zeolite, before the other materials are removed, are referred to as "precursors."

[0022] In the context of this specification, the terms "as-synthesized", "as-synthesized form" or "as-synthesized zeolite" refer to the state of the zeolite after the synthesis step is completed and before the start of post-treatment steps (e.g., calcination steps). A specific example of the as-synthesized state is the state shown immediately after the synthesis step, which is generally referred to as the zeolite precursor. In this respect, the as-synthesized zeolite may contain water and / or organic matter (especially organic structure directing agents).

[0023] In the context of this specification, the term "calcined", "calcined form" or "calcined zeolite" refers to the state of the zeolite after calcination. A specific example of the calcined state may be the state exhibited by calcining the as-synthesized zeolite to further remove any organic matter (especially organic structure-directing agents) and water in the pore channels.

[0024] In the context of this specification, in the XRD data of zeolites, terms such as w, m, s, vs, wm, ms, and s-vs represent the relative intensity I / I of the corresponding diffraction peak at the angle 2θ, calculated based on the diffraction peak intensity (measured by peak height) relative to the most intense diffraction peak (i.e., the diffraction peak with the highest intensity). Here, I refers to the peak intensity of the corresponding diffraction peak, I refers to the peak intensity of the most intense diffraction peak, w is weak, m is medium, s is strong, vs is very strong, wm is weak to medium, ms is medium to strong, and s-vs is strong to very strong. These expressions are well known to those skilled in the art. Generally, w is less than 20, m is 20 to 40, s is 40 to 70, vs is greater than 70, wm is less than 40, ms is 20 to 70, and s-vs is greater than 40.

[0025] In the context of this specification, the structure of a zeolite is determined using an X-ray diffraction spectrum after calcination at 550°C for 5 hours. The X-ray diffraction spectrum is determined using an X-ray powder diffractometer using a Cu-Kα source and a nickel filter. Before testing the sample, the crystallization of the zeolite sample is observed using a scanning electron microscope to confirm that the sample contains only one type of crystal, i.e., the zeolite sample is phase-pure. Based on this, an XRD test is performed to confirm that the diffraction peaks in the XRD spectrum are free of interference peaks from other crystals.

[0026] According to the present application, the interplanar spacings of various diffraction peaks in the XRD diffraction spectrum of a zeolite can be obtained by calculation based on the 2θ values ​​of the diffraction peaks from the Bragg formula: λ=2d sinθ (where λ is the wavelength of the incident wave, λ=1.54 Å, d is the interplanar spacing, and θ is the angle between the incident light beam and the scattering plane).

[0027] In the context of this specification, the term "specific surface area" refers to the total surface area of ​​a sample per unit mass, including the internal and external surface areas. Non-porous samples, such as Portland cement and clay mineral powder particles, only have an external surface area. Porous samples, such as asbestos fibers, diatomaceous earth, and zeolites, have both an external and internal surface area. The surface area of ​​pores with a pore size of less than 2 nanometers in a porous sample is defined as the internal surface area, and the surface area after subtracting the internal surface area is defined as the external surface area. The external surface area per unit mass of the sample is defined as the external specific surface area.

[0028] In the present context, the so-called "pore volume" refers to the volume of the pores of a zeolite per unit mass. The so-called "total pore volume" refers to the volume of all the pores of a zeolite per unit mass. The so-called "micropore volume" refers to the volume of all the micropores (generally pores with a pore channel diameter of less than 2 nanometers) of a zeolite per unit mass.

[0029] In this application, the pore structure parameters of the zeolite material, such as the total pore volume, micropore volume, total specific surface area, and external specific surface area, are obtained by measuring and obtaining the nitrogen physical adsorption and desorption isotherms of the zeolite using a physical adsorption apparatus (e.g., a TriStar 3000 physical adsorption apparatus manufactured by Micromeritics, USA) and calculating them using the BET method and t-plot method, where the total pore volume is the pore volume corresponding to a relative pressure P / P = 0.99. The experimental conditions for the physical adsorption and desorption of nitrogen are: a measurement temperature of -196°C, a vacuum pretreatment of the zeolite at 300°C for 10 hours before the measurement, and nitrogen as the adsorbate.

[0030] In the context of this specification, the so-called crystal thickness refers to the average thickness of all plate-like crystals within a randomly selected field of view when observing zeolite at a magnification of 100,000 times using a transmission electron microscope. This operation is repeated 10 times, and the average value of the 10 measurements is taken as the crystal thickness.

[0031] As mentioned above, in a first aspect, the present application provides a silicon-aluminum zeolite, the zeolite having a silicon / aluminum ratio n≧5, where n is preferably in the range of 5 to 80, more preferably in the range of 10 to 65, and the X-ray diffraction spectrum of the zeolite exhibits the relative intensity characteristics of the diffraction peaks as shown in the table below:

[0032] [Table 2]

[0033] In a preferred embodiment, the X-ray diffraction spectrum of the zeolite also exhibits relative intensities of diffraction peaks characteristic of the rows of any one of the following tables:

[0034] [Table 3]

[0035] In a further preferred embodiment, the X-ray diffraction spectrum of the zeolite also exhibits relative intensities of diffraction peaks characteristic of the values ​​shown in any row of the following table:

[0036] [Table 4]

[0037] The present silicon-aluminum zeolite SCM-36 has a structure not previously available in the art. According to the present application, the SCM-36 zeolite can exist in an uncalcined (as-synthesized) or calcined state. When present in a synthetic state, the SCM-36 zeolite typically has the formula "nSiO2-Al2O3-organic structure directing agent-water" or "nSiO2-Al2O3-mMO x When present in the calcined or synthesized state, the SCM-36 zeolite typically has the formula "nSiO2-Al2O3" or "nSiO2-Al2O3-mMO x", where n represents the silicon / aluminum ratio of the zeolite, n is ≧5, and m represents the molar ratio of elemental silicon to element M in the zeolite, and the value of m satisfies that the total content of element M in the zeolite is 3 mol % or less, based on the total amount of Si, Al, and element M, on an oxide basis. In the latter case, it is known that zeolites may contain a certain amount of water (especially immediately after synthesis). However, since the presence of water does not substantially affect the XRD spectrum of the zeolite, it is not necessary to determine the amount of water in this application. For this reason, the above-mentioned approximate chemical composition actually represents the anhydrous chemical composition of the zeolite.

[0038] In a preferred embodiment, the specific surface area of ​​the zeolite determined by the BET method is 300 to 700 m 2 / g, preferably 300 to 600m 2 / g, more preferably 350 to 500m 2 / g, e.g., 360-480m 2 / g; external specific surface area is 50~300m 2 / g, preferably 80 to 250m 2 / g, more preferably 100 to 220 m 2 / g.

[0039] In a preferred embodiment, the total pore volume of the zeolite is between 0.20 and 1.50 cm 3 / g, preferably 0.40 to 1.20 cm 3 / g, more preferably 0.5 cm 3 / g~1.0cm 3 / g. The micropore volume determined by the t-plot method is 0.05 cm 3 / g~0.35cm 3 / g, preferably 0.08 cm 3 / g~0.30cm 3 / g, more preferably 0.09 cm 3 / g~0.25cm 3 / g.

[0040] In a preferred embodiment, the zeolite has a nanoflake crystalline morphology with a crystal thickness of <30 nanometers, preferably 5 nanometers to 25 nanometers, more preferably 7 to 20 nanometers, for example 10 nanometers to 20 nanometers.

[0041] In a preferred embodiment, the total acid content of the zeolite, determined by the NH3-temperature programmed desorption (NH3-TPD) method, is 400-1200 μmol / g, preferably 500-1000 μmol / g, and the content of weak acids, defined as acids with a desorption temperature of 100-250°C, is ≥ 40%, preferably 45-90%.

[0042] In a preferred embodiment, the Lewis acid / Brønsted acid ratio of the zeolite determined by pyridine adsorption infrared spectroscopy is 0.1 to 3.8, preferably 0.4 to 3.5.

[0043] In a preferred embodiment, the zeolite further comprises at least one element M selected from the group consisting of titanium, boron, zirconium, tin, iron, or combinations thereof.

[0044] In a further preferred embodiment, the total content of the element M in the zeolite is 3 mol% or less based on the total amount of Si, Al and element M, on an oxide basis (wherein the amounts of Si, Al and element M are calculated based on the oxide forms of SiO, AlO and element M, respectively).

[0045] In a second aspect, the present application provides a method for producing a silicon-aluminum zeolite, comprising the steps of: 1) crystallizing a mixture containing a silicon source, an aluminum source, an organic structure directing agent (A), an organic structure directing agent (B), an alkali source, and water to obtain a zeolite; and 2) optionally calcining the zeolite obtained in step 1); Here, the organic structure directing agent (A) is selected from tetramethylammonium compounds, and the organic structure directing agent (B) is selected from C6-16 alkylpyridinium compounds, n-octyltrimethylammonium compounds, or a combination thereof.

[0046] In a preferred embodiment, in the mixture of step 1), the molar ratio of the silicon source (calculated based on SiO), the aluminum source (calculated based on AlO), the organic structure directing agent (A), the organic structure directing agent (B), the alkali source, and water is 1:(0.01-0.20):(0.05-0.80):(0.05-0.80):(0.05-0.50):(8-80), preferably 1:(0.01-0.10):(0.08-0.65):(0.08-0.65):(0.08-0.45):(10-70), and more preferably 1:(0.02-0.07):(0.10-0.50):(0.10-0.50):(0.10-0.40):(12-60).

[0047] In the method of the present application, the crystallization in step 1) can be carried out in any manner conventionally known in the technical field, and an example thereof can be a method in which a silicon source, an aluminum source, an organic structure-directing agent, an alkali source, and water are mixed in predetermined ratios, and the resulting mixture is subjected to hydrothermal crystallization under crystallization conditions.

[0048] In a preferred embodiment, the crystallization temperature in step 1) is 120°C to 200°C, and the crystallization time is 1 to 15 days, preferably the crystallization temperature is 130°C to 190°C, and the crystallization time is 2 to 12 days, and more preferably the crystallization temperature is 140°C to 180°C, and the crystallization time is 3 to 9 days.

[0049] In the method of the present application, after the crystallization in step 1) is completed, the zeolite can be separated as a product from the resulting product mixture by any conventionally known separation method to obtain the silicon-aluminum zeolite SCM-36 of the present application. An example of the separation method is a method in which the resulting product mixture is filtered, washed, and dried. The filtration, washing, and drying can be carried out by any conventionally known method in the art. Specifically, the resulting product mixture can be filtered by suction, for example; washed by using deionized water, for example; and dried by placing it in a commercially available air-blowing oven. The drying temperature can be 40°C to 150°C, preferably 50°C to 120°C; and the drying time can be 1 hour to 30 hours, preferably 2 hours to 24 hours. Drying can be carried out under atmospheric pressure or reduced pressure.

[0050] In the method of the present application, if desired, the zeolite obtained in step 1) can also be calcined to remove the organic structure-directing agent and any water present, thereby obtaining a calcined zeolite (also referred to as the SCM-36 zeolite of the present application). Calcination may be performed by any method conventionally known in the art. For example, the calcination temperature is generally in the range of 300°C to 800°C, preferably 400°C to 650°C, and the calcination time is generally in the range of 1 hour to 12 hours, preferably 2 hours to 10 hours. Furthermore, the calcination is generally performed in an oxygen-containing atmosphere, such as air or an oxygen atmosphere.

[0051] According to the present application, the silicon source and aluminum source can be various silicon sources and aluminum sources conventionally used in the production of silicon-aluminum zeolites, and the present application does not strictly limit them. In a preferred embodiment, the silicon source is selected from the group consisting of silicic acid, silica gel, silica sol, tetraethyl silicate, sodium silicate, or a combination thereof; and the aluminum source is selected from the group consisting of aluminum hydroxide, aluminum oxide, aluminates, aluminum salts, and tetraalkoxyaluminum, or a combination thereof.

[0052] According to the present application, the alkali source can be any alkali source conventionally used in the production process of silicon-aluminum zeolite, and there is no strict limitation in the present application. In a preferred embodiment, the alkali source is selected from the group consisting of inorganic alkalis having alkali metals and / or alkaline earth metals as cations, or combinations thereof. For example, the alkali source can be selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, lithium hydroxide, or combinations thereof.

[0053] According to the present application, the organic structure-directing agent (A) is (CH3)4N as a cation. + In a preferred embodiment, the organic structure-directing agent (A) is selected from the group consisting of tetramethylammonium hydroxide, tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium iodide, or a combination thereof.

[0054] According to the present application, the organic structure-directing agent (B) is 10-16 R(C5H5N) is an alkyl group + Pyridinium compounds having CH as a cation 17 (CH3)3N + or a combination thereof. For example, 10-16 Alkylpyridinium hydroxide, C 10-16 Alkylpyridinium organic acid salts, C 10-16Examples of suitable organic structure-directing agents include alkylpyridinium inorganic acid salts, n-octyltrimethylammonium hydroxide, n-octyltrimethylammonium organic acid salts, and n-octyltrimethylammonium inorganic acid salts. In a preferred embodiment, the organic structure-directing agent (B) is selected from the group consisting of hexadecylpyridine bromide, tetradecylpyridine bromide, dodecylpyridine bromide, decylpyridine bromide, hexadecylpyridine chloride, tetradecylpyridine chloride, hexadecylpyridine hydroxide, n-octyltrimethylammonium chloride, n-octyltrimethylammonium bromide, n-octyltrimethylammonium hydroxide, or a combination thereof. More preferably, the organic structure-directing agent (B) is selected from the group consisting of hexadecylpyridine bromide, tetradecylpyridine bromide, dodecylpyridine bromide, hexadecylpyridine chloride, hexadecylpyridine hydroxide, n-octyltrimethylammonium chloride, n-octyltrimethylammonium bromide, or a combination thereof.

[0055] In a preferred embodiment, said mixture of step 1) further comprises at least one source of an element M selected from the group consisting of titanium, boron, zirconium, tin and iron.

[0056] In a further preferred embodiment, the titanium source is selected from a titanium-containing organometallic complex, a tetraalkoxytitanium, titanium dioxide, titanium nitrate, or a combination thereof; the boron source is selected from boric acid, a borate, borax, boron trioxide, or a combination thereof; the zirconium source is selected from a zirconium-containing organometallic complex, a zirconium salt, zirconium hydroxide, zirconium alcoholate, zirconium dioxide, or a combination thereof; the tin source is selected from a tin-containing organometallic complex, a tin salt, tin dioxide, or a combination thereof; and the iron source is selected from an iron-containing organometallic complex, iron nitrate, iron chloride, iron oxide, or a combination thereof.

[0057] In a more preferred embodiment, the molar ratio of the silicon source (calculated based on SiO2) to the element M source (calculated based on the corresponding oxide) is 1:(0.002-0.10), preferably 1:(0.005-0.05).

[0058] In a third aspect, there is provided a silicon-aluminum zeolite SCM-36 produced according to the methods of the present application.

[0059] The silicon-aluminum zeolite SCM-36 of the present application can be obtained and used in any physical form, such as powder, particles, or shaped products (strips, clover, etc.), and these physical forms can be obtained by any method conventionally known in the art, without any particular limitation.

[0060] In a fourth aspect, the present application provides a zeolite composition comprising a silico-aluminous zeolite SCM-36 according to the present application, or a silico-aluminous zeolite SCM-36 produced according to the method of the present application, and a binder.

[0061] The silicon-aluminum zeolite SCM-36 of the present application can be used in combination with additional materials to obtain a zeolite composition. Examples of these additional materials can include active and inactive materials. Examples of the active material can include synthetic zeolites, natural zeolites, or other types of zeolites. The inactive material (commonly referred to as a binder) is not strictly limited herein. For example, the inactive material can be one conventionally used in the manufacture of adsorbents or catalysts, including, but not limited to, clay, carclazite, silica, silica gel, alumina, or mixtures thereof. These additional materials can be used alone or in any combination. The amount of the additional material is not particularly limited and can refer to conventional amounts in the art.

[0062] According to the present application, the zeolite composition can be presented in any physical form, such as in the form of a powder, particles, or a shaped product (strip, clover, etc.), which can be obtained by any method conventionally known in the art, without any particular limitation.

[0063] In a fifth aspect, there is provided the use of the present silico-aluminous zeolite SCM-36 or zeolite composition, or the silico-aluminous zeolite SCM-36 produced according to the present method, as an adsorbent, catalyst, or catalyst support.

[0064] The SCM-36 zeolite or zeolite composition of the present application can be used, for example, as an adsorbent for separating at least one component from a mixture of multiple components in a gas or liquid phase. Specifically, for example, at least one component can be partially or substantially completely separated from a mixture of various components by contacting the mixture with the SCM-36 zeolite or zeolite composition to selectively adsorb the component. Examples of uses as an adsorbent include the removal of small amounts of water from organic solvents such as isopropanol, isobutanol, and isobutyl ketone, and the adsorption and removal of small amounts of water from natural gas.

[0065] Furthermore, SCM-36 zeolite or the zeolite composition of the present application can be used directly as a catalyst support, catalyst, or catalytically active component thereof, or can be used after any necessary treatment or transformation (e.g., ion exchange) conventionally performed on zeolites in the art. For example, SCM-36 zeolite can be used as a catalyst support. For example, metallic Pd can be supported on SCM-36 zeolite to obtain Pd / SCM-36, which can be used as a Pd catalyst for hydrogenation or dehydrogenation reactions using SCM-36 as a support; SCM-36 can also be used as a bifunctional catalyst, functioning as both a support for metallic Pd and as a solid acid catalyst material providing acid sites. Furthermore, reactants (e.g., hydrocarbons) can be subjected to a desired reaction in the presence of a catalyst containing SCM-36 zeolite or the zeolite composition of the present application, thereby obtaining a target product. Examples of predetermined reactions include the thermal decomposition of isopropylbenzene, the conversion of methanol to olefins or aromatic hydrocarbons, and the reaction of 2,5-dimethylfuran and / or 2,5-hexanedione feedstocks with ethylene to produce p-xylene.

[0066] In a sixth aspect, the present application provides a catalyst comprising or consisting of the silico-aluminum zeolite SCM-36 or the zeolite composition of the present application, or the silico-aluminum zeolite SCM-36 produced according to the method of the present application.

[0067] In a preferred embodiment, the catalyst is suitable for the reactions of pyrolysis of isopropylbenzene and conversion of methanol to olefins or aromatic hydrocarbons, and the reaction of 2,5-dimethylfuran and / or 2,5-hexanedione feedstocks with ethylene to prepare p-xylene.

[0068] In a seventh aspect, the present application provides a method for preparing p-xylene, the method comprising contacting and reacting a feedstock comprising 2,5-dimethylfuran, 2,5-hexanedione, or a combination thereof with ethylene in the presence of a catalyst comprising, or consisting of, the silicon-aluminum zeolite SCM-36 of the present application.

[0069] The method for preparing p-xylene described herein uses SCM-36 zeolite as a catalyst or catalytically active component. Under mild reaction conditions, 2,5-dimethylfuran and / or 2,5-hexanedione can be converted to p-xylene with high conversion and high efficiency, with very high selectivity for the product p-xylene. Meanwhile, the content of major impurities (such as polyalkylbenzenes, 2,5-hexanedione, and 2-cyclopentenone) in the resulting product is extremely low, significantly reducing the energy consumption required for separation. Furthermore, the SCM-36 zeolite used as the catalyst in this study is highly stable, and its catalytic performance remains unchanged even after being recycled four times.

[0070] In a preferred embodiment, the catalytic reaction is carried out in the presence of an organic solvent, and the type of organic solvent can be selected from a wide range. All common organic solvents are applicable in the present application. Preferably, the organic solvent is selected from the group consisting of n-hexane, n-heptane, γ-valerolactone, tetrahydrofuran, toluene, cyclohexane, or a combination thereof. The amount of the organic solvent can be selected from a wide range and can be determined based on the reaction requirements. In a preferred embodiment, the mass ratio of the organic solvent to the raw material is 8 to 60:1, preferably 10 to 30:1, which is advantageous for increasing the substrate conversion rate and the selectivity for the p-xylene product and reducing the content of major impurities in the product.

[0071] In the method of the present application, the amount of the catalyst can be selected within a wide range and can be specifically determined based on the reaction requirements. In a preferred embodiment, the mass ratio of the raw material to the catalyst is 0.6-30:1, preferably 1.0-10:1, which is advantageous for improving the substrate conversion rate and the selectivity of the p-xylene product and reducing the content of major impurities in the product.

[0072] In the method of the present application, the conditions for the catalytic reaction can be selected within a wide range and can be specifically determined based on the reaction requirements. In a preferred embodiment, the reaction conditions include the following: the reaction temperature is 160°C to 340°C, preferably 220°C to 270°C; the reaction time can be determined based on the temperature, for example, the reaction time can be 6 hours to 64 hours, preferably 8 hours to 48 hours, more preferably 18 hours to 40 hours; and the reaction pressure is 1 MPa to 8 MPa, preferably 2 MPa to 4 MPa. [Example] The technical solutions of the present application are further illustrated in detail by examples, but the scope of protection of the present application is not limited to these examples.

[0073] In the following examples and comparative examples, all reagents and raw materials used are commercially available products of analytical purity unless otherwise specified.

[0074] In the following examples and comparative examples, unless specific conditions are specified for the experimental methods, the conditions are selected according to conventional methods and conditions or commercially available specifications.

[0075] In the following examples and comparative examples, the XRD of the zeolite products was measured in the following manner: the phases of the samples were analyzed using a Panalytical X PERPRO X-ray powder diffractometer with a CuKα source (λ = 1.54 Å), a nickel filter, a 2θ scan range of 2 to 50°, an operating voltage of 40 KV, a current of 40 mA, and a scan rate of 10° / min.

[0076] In the following examples and comparative examples, the model of the inductively coupled plasma optical emission spectrometer (ICP) was Varian 725-ES, and the analytical sample was dissolved in hydrofluoric acid, and the content of elements in the sample was detected and obtained.

[0077] In the following examples and comparative examples, NH3 temperature-programmed desorption (NH3-TPD) experiments were performed using a TPD / TPR Altamira AMI-3300 instrument, and the total acid amount was calculated by peak fitting of the obtained spectrum. Acids corresponding to desorption temperatures of 100°C to 250°C were defined as weak acids, and the proportion of weak acids was calculated accordingly.

[0078] In the following examples and comparative examples, scanning electron microscope images were taken using a Hitachi S-4800II field emission scanning electron microscope manufactured by Hitachi, Ltd., Japan, under a test voltage of 15 kV. A G2F30 transmission electron microscope manufactured by FEI, the Netherlands, was used, operating at 300 kV. The zeolite was observed at a magnification of 100,000 times, and the thickness of all crystals within a randomly selected observation field was measured. This procedure was repeated five times, and the average of the five measurements was taken as the average thickness of the crystals.

[0079] In the following examples and comparative examples, Py-FTIR spectrograms were run on a Thermo Nicolet 5700 FT-IR spectrometer.

[0080] Example I-1 A mixture was prepared by uniformly mixing 24.73 g of deionized water, 6.89 g of sodium hydroxide solution (containing 10 wt% NaOH), 5.35 g of organic structure directing agent (A): tetramethylammonium hydroxide (containing 25 wt% TMAOH), 3.05 g of organic structure directing agent (B): n-octyltrimethylammonium chloride, 1.234 g of sodium metaaluminate (containing 40.5 wt% Al2O3 and 30.6 wt% Na2O), and 14.72 g of silica sol (containing 40 wt% SiO2). The molar ratio of the reactants was as follows: Al2O3 / SiO2=0.05 Tetramethylammonium hydroxide (A) / SiO2=0.15 n-Octyltrimethylammonium chloride (B) / SiO2=0.15 NaOH / SiO2=0.30 H2O / SiO2=25; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 6 days at 160°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 110°C for 12 hours, and calcined in air at 550°C for 6 hours to obtain zeolite.

[0081] The XRD spectrum data of the dried sample is shown in Table I-1 and Figure 1, the SEM image of the sample is shown in Figure 2, and the TEM image is shown in Figure 3.

[0082] [Table 5]

[0083] The specific surface area of ​​the resulting calcined product is 380m 2 / g, external specific surface area is 170m 2 / g, total pore volume is 0.92 cm 3 / g, micropore volume is 0.10 cm 3 / g. The sample has a nanoflake-like morphology, with a crystal thickness of approximately 15 nanometers.

[0084] This calcined sample had a molar ratio of SiO2 / Al2O3 = 21.6 as measured using inductively coupled plasma optical emission spectroscopy (ICP).

[0085] The ammonia temperature-programmed desorption (NH3-TPD) spectrum of the obtained sample is shown in Figure 4. As a result, the total acid content was 782 μmol / g, and the weak acid content was 63%. The infrared spectrum of pyridine adsorption is shown in Figure 5, and the Lewis / Brønsted acid ratio was analyzed and measured to be 2.2.

[0086] Example I-2 The test was carried out with reference to Example I-1, except for the ratios (molar ratios) of reactants and materials used: Al2O3 / SiO2=0.067 Tetramethylammonium hydroxide (A) / SiO2=0.15 n-Octyltrimethylammonium chloride (B) / SiO2=0.20 NaOH / SiO2=0.30 H2O / SiO2=20; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 5 days at 160°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 100°C for 16 hours, and calcined in air at 550°C for 8 hours to obtain zeolite.

[0087] The XRD spectrum data of the dried sample is shown in Table 1-2 and FIG. 6, and the SEM image of the sample is similar to that shown in FIG.

[0088] [Table 6]

[0089] The specific surface area of ​​the resulting calcined product was 392 m 2 / g, external specific surface area is 166m 2 / g, total pore volume is 0.73 cm 3 / g, micropore volume is 0.10 cm 3 / g. The sample has a nanoflake morphology, with a crystal thickness of about 12 nanometers.

[0090] The calcined sample had a molar ratio of SiO2 / Al2O3 = 15.6 as measured using inductively coupled plasma optical emission spectroscopy (ICP).

[0091] The ammonia temperature-programmed desorption (NH3-TPD) spectrum of the obtained sample was similar to that shown in Figure 4. As a result, the total acid content was 827 μmol / g and the weak acid content was 61%. The infrared spectrum of pyridine adsorption was similar to that shown in Figure 5, and the Lewis / Brønsted acid ratio was analyzed and measured to be 2.5.

[0092] Example I-3 The test was carried out with reference to Example I-1, except for the ratios (molar ratios) of reactants and materials used: Al2O3 / SiO2=0.04 Tetramethylammonium chloride (A) / SiO2=0.20 n-Octyltrimethylammonium chloride (B) / SiO2=0.15 NaOH / SiO2=0.25 H2O / SiO2=35; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 7 days at 155°C. After crystallization was completed, the product was filtered, washed, dried in an oven at 80°C for 16 hours, and calcined in air at 500°C for 10 hours to obtain zeolite.

[0093] The XRD spectrum data of the dried sample is shown in Table I-3, and the SEM image of the sample is shown in FIG.

[0094] [Table 7]

[0095] The specific surface area of ​​the resulting calcined product was 388 m 2 / g, external specific surface area is 162m 2 / g, total pore volume is 0.75 cm 3 / g, micropore volume is 0.10 cm 3 / g. The sample has a nanoflake morphology, with a crystal thickness of about 13 nanometers.

[0096] The calcined sample had a molar ratio of SiO2 / Al2O3 = 26.1 as measured using inductively coupled plasma optical emission spectroscopy (ICP).

[0097] The ammonia temperature-programmed desorption (NH3-TPD) spectrum of the obtained sample was similar to that shown in Figure 4. As a result, the total acid content was 674 μmol / g and the weak acid content was 68%. The infrared spectrum of pyridine adsorption was similar to that shown in Figure 5, and the Lewis / Brønsted acid ratio was analyzed and measured to be 1.1.

[0098] Example I-4 The test was carried out with reference to Example I-1, except for the ratios (molar ratios) of reactants and materials used: Al2O3 / SiO2=0.045 Tetramethylammonium hydroxide (A) / SiO2=0.25 n-Octyltrimethylammonium chloride (B) / SiO2=0.15 NaOH / SiO2=0.20 H2O / SiO2=45; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 4 days at 165°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 60°C for 24 hours, and calcined in air at 600°C for 4 hours to obtain zeolite.

[0099] The XRD spectrum data of the dried sample is shown in Table I-4, and the SEM image of the sample is similar to that shown in FIG.

[0100] [Table 8]

[0101] The specific surface area of ​​the resulting calcined product was 377 m 2 / g, external specific surface area is 158m 2 / g, total pore volume is 0.74 cm 3 / g, micropore volume is 0.11 cm 3 / g. The sample has a nanoflake morphology, with a crystal thickness of about 11 nanometers.

[0102] The calcined sample had a molar ratio of SiO2 / Al2O3 = 22.3 as measured using inductively coupled plasma optical emission spectroscopy (ICP).

[0103] The ammonia temperature-programmed desorption (NH3-TPD) spectrum of the obtained sample was similar to that shown in Figure 4. As a result, the total acid content was 835 μmol / g and the weak acid content was 64%. The infrared spectrum of pyridine adsorption was similar to that shown in Figure 5, and the Lewis / Brønsted acid ratio was analyzed and measured to be 2.8.

[0104] Example I-5 The test was carried out with reference to Example I-1, except for the ratios (molar ratios) of reactants and materials used: Al2O3 / SiO2=0.017 Tetramethylammonium hydroxide (A) / SiO2=0.20 n-Octyltrimethylammonium chloride (B) / SiO2=0.25 NaOH / SiO2=0.20 H2O / SiO2=30; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 8 days at 155°C. After crystallization was completed, the product was filtered, washed with water, dried in an oven at 120°C for 6 hours, and calcined in air at 550°C for 8 hours to obtain zeolite.

[0105] The XRD spectral data of the dried sample is shown in Table I-5, and the SEM image of the sample is similar to that shown in FIG.

[0106] [Table 9]

[0107] The specific surface area of ​​the resulting calcined product is 372 m 2 / g, external specific surface area is 149m 2 / g, total pore volume is 0.74 cm 3 / g, micropore volume is 0.09 cm 3 / g. The sample has a nanoflake morphology, with a crystal thickness of about 12 nanometers.

[0108] The calcined sample had a molar ratio of SiO2 / Al2O3 = 61.5 as measured using inductively coupled plasma optical emission spectroscopy (ICP).

[0109] The ammonia temperature-programmed desorption (NH3-TPD) spectrum of the obtained sample was similar to that shown in Figure 4. As a result, the total acid content was 621 μmol / g and the weak acid content was 56%. The infrared spectrum of pyridine adsorption was similar to that shown in Figure 5, and the Lewis / Brønsted acid ratio was analyzed and measured to be 1.0.

[0110] Example I-6 The test was carried out with reference to Example I-1, except for the ratios (molar ratios) of reactants and materials used: Al2O3 / SiO2=0.03 Tetramethylammonium iodide (A) / SiO2=0.20 n-Octyltrimethylammonium chloride (B) / SiO2=0.20 NaOH / SiO2=0.25 H2O / SiO2=35; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 5 days at 170°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 100°C for 12 hours, and calcined in air at 500°C for 10 hours to obtain zeolite.

[0111] The XRD spectrum data of the dried sample is shown in Table I-6, and the SEM image of the sample is similar to that shown in FIG.

[0112] [Table 10]

[0113] The specific surface area of ​​the resulting calcined product is 362 m 2 / g, external specific surface area is 149m 2 / g, total pore volume is 0.67 cm 3 / g, micropore volume is 0.10 cm 3 / g. The sample has a nanoflake morphology, with a crystal thickness of about 12 nanometers.

[0114] The calcined sample had a molar ratio of SiO2 / Al2O3 = 34.5 as measured using inductively coupled plasma optical emission spectroscopy (ICP).

[0115] The ammonia temperature-programmed desorption (NH3-TPD) spectrum of the obtained sample was similar to that shown in Figure 4. As a result, the total acid content was 643 μmol / g and the weak acid content was 66%. The infrared spectrum of pyridine adsorption was similar to that shown in Figure 5, and the Lewis / Brønsted acid ratio was analyzed and measured to be 2.1.

[0116] Example I-7 The test was carried out with reference to Example I-1, except for the ratios (molar ratios) of reactants and materials used: Al2O3 / SiO2=0.05 Tetramethylammonium hydroxide (A) / SiO2=0.15 Tetradecylpyridine bromide (B) / SiO2=0.15 NaOH / SiO2=0.30 H2O / SiO2=35; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 7 days at 160°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 110°C for 6 hours, and calcined in air at 550°C for 6 hours to obtain zeolite.

[0117] The XRD spectrum data of the dried sample is shown in Table I-7, and the SEM image of the sample is similar to that shown in FIG.

[0118] [Table 11]

[0119] The specific surface area of ​​the obtained calcined product was 378 m 2 / g, external specific surface area is 156m 2 / g, total pore volume is 0.77 cm3 / g, micropore volume is 0.11 cm 3 / g. The sample has a nanoflake morphology, with a crystal thickness of about 13 nanometers.

[0120] The calcined sample had a molar ratio of SiO2 / Al2O3 = 21.1 as measured using inductively coupled plasma optical emission spectroscopy (ICP).

[0121] The ammonia temperature-programmed desorption (NH3-TPD) spectrum of the obtained sample was similar to that shown in Figure 4. As a result, the total acid content was 815 μmol / g and the weak acid content was 68%. The infrared spectrum of pyridine adsorption was similar to that shown in Figure 5, and the Lewis / Brønsted acid ratio was analyzed and measured to be 1.7.

[0122] Example I-8 The test was carried out with reference to Example I-1, except that hexadecylpyridine bromide was used as the organic structure-directing agent (B) and the following material ratio (molar ratio) of the reactants was used: Al2O3 / SiO2=0.045 Tetramethylammonium hydroxide (A) / SiO2=0.15 Hexadecylpyridine bromide (B) / SiO2=0.20 NaOH / SiO2=0.25 H2O / SiO2=30; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 6 days at 160°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 90°C for 12 hours, and calcined in air at 550°C for 6 hours to obtain zeolite.

[0123] The XRD spectrum data of the dried sample is shown in Table I-8, and the SEM image of the sample is similar to that shown in FIG.

[0124] [Table 12]

[0125] The specific surface area of ​​the resulting calcined product was 394 m 2 / g, external specific surface area is 171m 2 / g, total pore volume is 0.68 cm 3 / g, micropore volume is 0.12 cm 3 / g. The sample has a nanoflake morphology, with a crystal thickness of about 12 nanometers.

[0126] The calcined sample had a molar ratio of SiO2 / Al2O3 = 22.8 as measured using inductively coupled plasma optical emission spectroscopy (ICP).

[0127] The ammonia temperature-programmed desorption (NH3-TPD) spectrum of the obtained sample was similar to that shown in Figure 4. As a result, the total acid content was 849 μmol / g and the weak acid content was 59%. The infrared spectrum of pyridine adsorption was similar to that shown in Figure 5, and the Lewis / Brønsted acid ratio was analyzed and measured to be 2.3.

[0128] Example I-9 The test was carried out with reference to Example I-8, except that the ratios (molar ratios) of reactants and materials used were as follows: Al2O3 / SiO2=0.068 Tetramethylammonium hydroxide (A) / SiO2=0.20 Hexadecylpyridine bromide (B) / SiO2=0.15 NaOH / SiO2=0.30 H2O / SiO2=40; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 6 days at 160°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 80°C for 16 hours, and calcined in air at 550°C for 6 hours to obtain zeolite.

[0129] The XRD spectrum data of the dried sample is shown in Table I-9. The SEM image of the sample is the same as that shown in Figure 2.

[0130] [Table 13]

[0131] The specific surface area of ​​the resulting calcined product is 372 m 2 / g, external specific surface area is 144m 2 / g, total pore volume is 0.65 cm 3 / g, micropore volume is 0.11 cm 3 / g. The sample has a nanoflake morphology, with a crystal thickness of about 15 nanometers.

[0132] The calcined sample had a molar ratio of SiO2 / Al2O3 = 14.5 as measured using inductively coupled plasma optical emission spectroscopy (ICP).

[0133] The ammonia temperature-programmed desorption (NH3-TPD) spectrum of the obtained sample was similar to that shown in Figure 4. As a result, the total acid content was 896 μmol / g and the weak acid content was 82%. The infrared spectrum of pyridine adsorption was similar to that shown in Figure 5, and the Lewis / Brønsted acid ratio was analyzed and measured to be 3.0.

[0134] Example I-10 The test was carried out with reference to Example I-1, except for the following reactant and material ratios (molar ratios) used: Al2O3 / SiO2=0.05 TiO2 / SiO2=0.01 Tetramethylammonium hydroxide (A) / SiO2=0.15 n-Octyltrimethylammonium chloride (B) / SiO2=0.20 NaOH / SiO2=0.25 H2O / SiO2=35; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 7 days at 160°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 100°C for 10 hours, and calcined in air at 550°C for 6 hours to obtain zeolite.

[0135] The XRD spectrum data of the dried sample is shown in Table 1-10. The SEM image of the sample is similar to that shown in Figure 2.

[0136] [Table 14]

[0137] The specific surface area of ​​the resulting calcined product is 364 m 2 / g, external specific surface area is 146m 2 / g, total pore volume is 0.71 cm 3 / g, micropore volume is 0.12 cm 3 / g. The sample has a nanoflake morphology with a crystal thickness of about 18 nanometers.

[0138] The calcined sample has a molar ratio of SiO2 / Al2O3=21.2 and a molar ratio of SiO2 / TiO2=106.2 as measured using inductively coupled plasma optical emission spectroscopy (ICP).

[0139] The ammonia temperature-programmed desorption (NH3-TPD) spectrum of the obtained sample was similar to that shown in Figure 4. As a result, the total acid content was 795 μmol / g and the weak acid content was 60%. The infrared spectrum of pyridine adsorption was similar to that shown in Figure 5, and the Lewis / Brønsted acid ratio was analyzed and measured to be 1.6.

[0140] Example I-11 The test was carried out with reference to Example I-1, except for the following reactant and material ratios (molar ratios) used: Al2O3 / SiO2=0.065 B2O3 / SiO2=0.012 Tetramethylammonium hydroxide (A) / SiO2=0.20 n-Octyltrimethylammonium chloride (B) / SiO2=0.15 NaOH / SiO2=0.30 H2O / SiO2=40; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 7 days at 155°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 80°C for 8 hours, and calcined in air at 550°C for 6 hours to obtain zeolite.

[0141] The XRD spectrum data of the dried sample is shown in Table 1-11. The SEM image of the sample is the same as that shown in Figure 2.

[0142] [Table 15]

[0143] The specific surface area of ​​the resulting calcined product was 385 m 2 / g, external specific surface area is 152m 2 / g, total pore volume is 0.63 cm 3 / g, micropore volume is 0.09 cm 3 / g. The sample has a nanoflake morphology, with a crystal thickness of about 20 nanometers.

[0144] The calcined sample has a molar ratio of SiO2 / Al2O3=15.9 and a molar ratio of SiO2 / B2O3=96.3 as measured using inductively coupled plasma optical emission spectroscopy (ICP).

[0145] The ammonia temperature-programmed desorption (NH3-TPD) spectrum of the obtained sample was similar to that shown in Figure 4. As a result, the total acid content was 860 μmol / g and the weak acid content was 74%. The infrared spectrum of pyridine adsorption was similar to that shown in Figure 5, and the Lewis / Brønsted acid ratio was analyzed and measured to be 3.2.

[0146] Example I-12 The test was carried out with reference to Example I-7, and the ratios (molar ratios) of reactants and materials used were as follows: Al2O3 / SiO2=0.035 ZrO2 / SiO2=0.008 Tetramethylammonium hydroxide (A) / SiO2=0.20 Dodecylpyridine bromide (B) / SiO2=0.20 NaOH / SiO2=0.25 H2O / SiO2=30; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 6 days at 165°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 110°C for 12 hours, and calcined in air at 550°C for 5 hours to obtain zeolite.

[0147] The XRD spectrum data of the dried sample is shown in Table I-12, and the SEM image of the sample is similar to that shown in FIG.

[0148] [Table 16]

[0149] The specific surface area of ​​the resulting calcined product is 373 m 2 / g, external specific surface area is 148m 2 / g, total pore volume is 0.75 cm 3 / g, micropore volume is 0.09 cm 3 / g. The sample has a nanoflake morphology with a crystal thickness of about 16 nanometers.

[0150] The calcined sample has a molar ratio of SiO2 / Al2O3=30.6 and a molar ratio of SiO2 / ZrO2=131.2 as measured using inductively coupled plasma optical emission spectroscopy (ICP).

[0151] The ammonia temperature-programmed desorption (NH3-TPD) spectrum of the obtained sample was similar to that shown in Figure 4. As a result, the total acid content was 773 μmol / g and the weak acid content was 63%. The infrared spectrum of pyridine adsorption was similar to that shown in Figure 5, and the Lewis / Brønsted acid ratio was analyzed and measured to be 2.8.

[0152] Example I-13 The test was carried out with reference to Example I-1, except for the following reactant and material ratios (molar ratios) used: Al2O3 / SiO2=0.05 SnO2 / SiO2=0.008 Tetramethylammonium bromide (A) / SiO2=0.15 n-Octyltrimethylammonium bromide (B) / SiO2=0.20 NaOH / SiO2=0.30 H2O / SiO2=25; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 7 days at 160°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 110°C for 12 hours, and calcined in air at 550°C for 6 hours to obtain zeolite.

[0153] The XRD spectrum data of the dried sample is shown in Table 1-13. The SEM image of the sample is similar to that shown in Figure 2.

[0154] [Table 17]

[0155] The specific surface area of ​​the resulting calcined product was 386 m 2 / g, external specific surface area is 154m 2 / g, total pore volume is 0.73 cm 3 / g, micropore volume is 0.10 cm 3 / g. The sample has a nanoflake morphology, with a crystal thickness of about 15 nanometers.

[0156] The calcined sample has a molar ratio of SiO2 / Al2O3=21.5 and a molar ratio of SiO2 / SnO2=126.4 as measured using inductively coupled plasma optical emission spectroscopy (ICP).

[0157] The ammonia temperature-programmed desorption (NH3-TPD) spectrum of the obtained sample was similar to that shown in Figure 4. As a result, the total acid content was 794 μmol / g, and the weak acid content was 66%. The infrared spectrum of pyridine adsorption was similar to that shown in Figure 5, and the Lewis / Brønsted acid ratio was analyzed and measured to be 2.4.

[0158] Example I-14 The test was carried out with reference to Example I-8, and the ratios (molar ratios) of reactants and materials used were as follows: Al2O3 / SiO2=0.04 Fe2O3 / SiO2=0.005 Tetramethylammonium chloride (A) / SiO2=0.15 Hexadecylpyridine hydroxide (B) / SiO2=0.25 NaOH / SiO2=0.20 H2O / SiO2=30; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 7 days at 165°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 110°C for 12 hours, and calcined in air at 550°C for 6 hours to obtain zeolite.

[0159] The XRD spectral data of the dried sample is shown in Table I-14, and the SEM image of the sample is shown in FIG.

[0160] [Table 18]

[0161] The specific surface area of ​​the resulting calcined product was 383 m 2 / g, external specific surface area is 155m 2 / g, total pore volume is 0.75 cm 3 / g, micropore volume is 0.10 cm 3 / g. The sample has a nanoflake morphology, with a crystal thickness of about 17 nanometers.

[0162] The calcined sample has a molar ratio of SiO2 / Al2O3=26.5 and a molar ratio of SiO2 / Fe2O3=188.4 as measured using inductively coupled plasma optical emission spectroscopy (ICP).

[0163] The ammonia temperature-programmed desorption (NH3-TPD) spectrum of the obtained sample was similar to that shown in Figure 4. As a result, the total acid content was 787 μmol / g and the weak acid content was 68%. The infrared spectrum of pyridine adsorption was similar to that shown in Figure 5, and the Lewis / Brønsted acid ratio was analyzed and measured to be 1.8.

[0164] Example I-15 The test was carried out with reference to Example I-1, except for the ratios (molar ratios) of reactants and materials used: Al2O3 / SiO2=0.045 Tetramethylammonium hydroxide (A) / SiO2=0.45 Dodecylpyridine bromide (B) / SiO2=0.20 NaOH / SiO2=0.25 H2O / SiO2=25; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 6 days at 160°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 110°C for 12 hours, and calcined in air at 550°C for 6 hours to obtain zeolite.

[0165] The XRD spectrum data of the dried sample is shown in Table 1-15. The SEM image of the sample is similar to that shown in Figure 2.

[0166] [Table 19]

[0167] The specific surface area of ​​the resulting calcined product is 368 m 2 / g, external specific surface area is 145m 2 / g, total pore volume is 0.72 cm 3 / g, micropore volume is 0.09 cm 3 / g. The sample has a nanoflake morphology, with a crystal thickness of about 17 nanometers.

[0168] The calcined sample had a molar ratio of SiO2 / Al2O3 = 22.8 as measured using inductively coupled plasma optical emission spectroscopy (ICP).

[0169] The ammonia temperature-programmed desorption (NH3-TPD) spectrum of the obtained sample was similar to that shown in Figure 4. As a result, the total acid content was 861 μmol / g and the weak acid content was 57%. The infrared spectrum of pyridine adsorption was similar to that shown in Figure 5, and the Lewis / Brønsted acid ratio was analyzed and measured to be 2.0.

[0170] Example I-16 The test was carried out with reference to Example I-7. The ratios (molar ratios) of reactants and materials used were as follows: Al2O3 / SiO2=0.040 Tetramethylammonium chloride (A) / SiO2=0.15 Dodecylpyridine bromide (B) / SiO2=0.45 NaOH / SiO2=0.15 H2O / SiO2=30; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 8 days at 160°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 110°C for 12 hours, and calcined in air at 550°C for 6 hours to obtain zeolite.

[0171] The XRD spectrum data of the dried sample is shown in Table 1-16. The SEM image of the sample is similar to that shown in Figure 2.

[0172] [Table 20]

[0173] The specific surface area of ​​the resulting calcined product was 388 m 2 / g, external specific surface area is 159m 2 / g, total pore volume is 0.71 cm 3 / g, micropore volume is 0.10 cm 3 / g. The sample has a nanoflake morphology, with a crystal thickness of about 17 nanometers.

[0174] The calcined sample had a molar ratio of SiO2 / Al2O3 = 26.1 as measured using inductively coupled plasma optical emission spectroscopy (ICP).

[0175] The ammonia temperature-programmed desorption (NH3-TPD) spectrum of the obtained sample was similar to that shown in Figure 4. As a result, the total acid content was 872 μmol / g and the weak acid content was 75%. The infrared spectrum of pyridine adsorption was similar to that shown in Figure 5, and the Lewis / Brønsted acid ratio was analyzed and measured to be 3.0.

[0176] Example I-17 The test was carried out with reference to Example I-1, except for the ratios (molar ratios) of reactants and materials used: Al2O3 / SiO2=0.05 Tetramethylammonium hydroxide (A) / SiO2=0.20 Hexadecylpyridine chloride (B) / SiO2=0.25 NaOH / SiO2=0.15 H2O / SiO2=20; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 7 days at 160°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 110°C for 12 hours, and calcined in air at 550°C for 6 hours to obtain zeolite.

[0177] The XRD spectrum data of the dried sample is shown in Table I-17, and the SEM image of the sample is similar to that shown in FIG.

[0178] [Table 21]

[0179] The specific surface area of ​​the resulting calcined product was 392 m 2 / g, external specific surface area is 159m 2 / g, total pore volume is 0.72 cm 3 / g, micropore volume is 0.09 cm 3 / g. The sample has a nanoflake morphology, with a crystal thickness of about 15 nanometers.

[0180] The calcined sample had a molar ratio of SiO2 / Al2O3 = 21.6 as measured using inductively coupled plasma optical emission spectroscopy (ICP).

[0181] The ammonia temperature-programmed desorption (NH3-TPD) spectrum of the obtained sample was similar to that shown in Figure 4. As a result, the total acid content was 908 μmol / g and the weak acid content was 79%. The infrared spectrum of pyridine adsorption was similar to that shown in Figure 5, and the Lewis / Brønsted acid ratio was analyzed and measured to be 3.2.

[0182] Comparative example I-1 The test was carried out with reference to Example I-1, except for the ratios (molar ratios) of reactants and materials used: Al2O3 / SiO2=0.22 Tetramethylammonium hydroxide (A) / SiO2=0.15 n-Octyltrimethylammonium chloride (B) / SiO2=0.15 NaOH / SiO2=0.30 H2O / SiO2=25; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 6 days at 160°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 110°C for 12 hours, and calcined in air at 550°C for 6 hours to obtain zeolite.

[0183] The XRD spectrum data of the dried sample is shown in Figure 8. The dried sample is an amorphous material and is not SCM-36 zeolite.

[0184] Comparative example I-2 The test was carried out with reference to Example I-1, except for the ratios (molar ratios) of reactants and materials used: Al2O3 / SiO2=0.05 Tetramethylammonium hydroxide (A) / SiO2=0.15 n-Octyltrimethylammonium chloride (B) / SiO2=0.15 NaOH / SiO2=0.55 H2O / SiO2=25; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 6 days at 160°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 110°C for 12 hours, and calcined in air at 550°C for 6 hours to obtain zeolite.

[0185] The XRD spectrum data of the dried sample is similar to that shown in Figure 8. The dried sample is an amorphous material and is not SCM-36 zeolite.

[0186] Comparative example I-3 The test was carried out with reference to Example I-1, except that octylamine was used as the organic structure directing agent (B) and the ratios (molar ratios) of reactants and materials used were as follows: Al2O3 / SiO2=0.05 Tetramethylammonium hydroxide (A) / SiO2=0.15 Octylamine (B) / SiO2=0.15 NaOH / SiO2=0.30 H2O / SiO2=25; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 6 days at 160°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 110°C for 12 hours, and calcined in air at 550°C for 6 hours to obtain zeolite.

[0187] The XRD spectrum data of the dried sample is shown in Figure 9. The dried sample is a mixture of MOR and a zeolite with a different structure than SCM-36 zeolite.

[0188] Comparative example I-4 Tests were carried out with reference to Example I-1, except that only tetramethylammonium hydroxide was used as the organic structure-directing agent and the ratio (molar ratio) of the reactants and materials used was changed: Al2O3 / SiO2=0.05 Tetramethylammonium hydroxide / SiO2=0.15 NaOH / SiO2=0.30 H2O / SiO2=25; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 6 days at 160°C. After the crystallization was completed, the product was filtered, washed, dried in an oven at 110°C for 12 hours, and calcined in air at 550°C for 6 hours to obtain zeolite.

[0189] The XRD spectrum data of the dried sample is shown in Figure 10. The dried sample is a mixture of SOD and a zeolite with a different structure than SCM-36 zeolite.

[0190] Example I-18 The zeolite synthesized in Example I-5 was ion-exchanged with a 0.5 mol / L NH4Cl solution (the mass ratio of zeolite to ammonium chloride solution was 1:20) at 70°C for 2 hours, then centrifuged and washed. The sample obtained after two ion exchanges was dried at 100°C for 12 hours and calcined at 550°C for 6 hours to obtain H-type SCM-36 zeolite.

[0191] The powder sample of the calcined H-type SCM-36 zeolite was crushed, and a portion of the sample with a particle size of 20 to 40 mesh was sieved and placed in a fixed-bed reactor to carry out the thermal decomposition reaction of isopropylbenzene. The reaction conditions were a reaction temperature of 320°C, a reaction pressure of atmospheric pressure, and an isopropylbenzene weight hourly space velocity of 2 h. -1 The product was analyzed using a Shimadzu GC-2014 gas chromatograph. After 1 hour of reaction, the conversion of isopropylbenzene was 25.2%, and the selectivity of benzene in the product was 94.1%.

[0192] In this example, isopropylbenzene was used as a raw material and subjected to a thermal decomposition reaction, which was thermally decomposed into products such as propylene and benzene under the action of a catalyst.

[0193] Conversion rate of isopropylbenzene %=(molar amount of isopropylbenzene fed−molar amount of isopropylbenzene in the product) / (molar amount of isopropylbenzene fed)×100%.

[0194] Benzene selectivity = (molar amount of benzene in the product) / (total mole amount of aromatic hydrocarbons in the product) × 100%; Here, the aromatic hydrocarbons in the product do not contain the raw material isopropylbenzene.

[0195] Example I-19 The zeolite synthesized in Example I-5 was ion-exchanged with a 0.5 mol / L NH4Cl solution (the mass ratio of zeolite to ammonium chloride solution was 1:20) at 70°C for 2 hours, then centrifuged and washed. The sample obtained after two ion exchanges was dried at 100°C for 12 hours and calcined at 550°C for 6 hours to obtain H-type SCM-36 zeolite.

[0196] The powder sample of the calcined H-type SCM-36 zeolite was crushed, and a portion of the sample with a particle size of 20 to 40 mesh was sieved and placed in a fixed-bed reactor to carry out a methanol conversion reaction. The reaction conditions were a reaction temperature of 460°C, a reaction pressure of 0.1 MPa, and a weight hourly space velocity of the raw material methanol of 1 h . -1 The products were analyzed using a Shimadzu GC-2014 gas chromatograph. After 45 minutes of reaction, the methanol conversion was 99.0%, the selectivity for C2-C4 olefins in the products was 58.6%, and the selectivity for aromatic hydrocarbons was 4.2%.

[0197] In this example, the methanol conversion reaction is a reaction in which the raw material methanol is converted into hydrocarbons such as olefins and aromatic hydrocarbons under the action of a catalyst.

[0198] Methanol conversion % = (mole amount of methanol fed - molar amount of methanol in product - 2 × molar amount of dimethyl ether in product) / (mole amount of methanol fed) × 100%; Selectivity for C2-C4 olefins = (molar amount of C2 olefins in product × 2 + molar amount of C3 olefins in product × 3 + molar amount of C4 olefins in product × 4) / (molar amount of methanol fed − molar amount of methanol in product − molar amount of dimethyl ether in product × 2) × 100%.

[0199] Aromatic hydrocarbon selectivity = (molar amount of benzene in the product × 6 + mole amount of toluene in the product × 7 + mole amount of xylene in the product × 8) / (molar amount of methanol fed − mole amount of methanol in the product − mole amount of dimethyl ether in the product × 2) × 100%.

[0200] In the following examples and comparative examples, the reaction products of p-xylene were qualitatively analyzed by gas chromatography-mass spectrometry (GC-MS), and the conversion of the substrates 2,5-methylfuran and / or 2,5-hexanedione and the yield of the reaction products of pX were analyzed by gas chromatography (GC). The gas chromatograph-mass spectrometer was an Agilent 7890A (Agilent, USA), and the chromatography column was an HP-5 nonpolar capillary column (30 m, 0.53 mm). The gas chromatograph was an Agilent 7890B, and the detector was a flame ionization detector (FID), and the chromatography column was an SE-54 capillary column (30 m, 0.53 mm).

[0201] In the following examples and comparative examples, the formula for the conversion of 2,5-dimethylfuran (or 2,5-hexanedione) is as follows: Conversion rate of 2,5-dimethylfuran (and / or 2,5-hexanedione) % = (molar amount of 2,5-dimethylfuran (and / or 2,5-hexanedione) participating in the reaction) / (molar amount of 2,5-dimethylfuran (and / or 2,5-hexanedione) as the reaction substrate) × 100%.

[0202] In this application, the formula for calculating the product yield of p-xylene (pX) is as follows: The percent yield of pX product = (molar amount of pX produced in the reaction) / (molar amount of the reaction substrate, 2,5-dimethylfuran (and / or 2,5-hexanedione)) × 100%.

[0203] In this application, the formula for calculating the product selectivity for p-xylene is as follows: Selectivity of pX product % = (molar amount of pX produced in the reaction) / (molar amount of 2,5-dimethylfuran (and / or 2,5-hexanedione) reacted) × 100%.

[0204] Example II-1 n-Heptane was used as the reaction solvent. The mass ratio of n-heptane to 2,5-dimethylfuran (DMF) was 20, and the mass ratio of DMF to catalyst was 1. The reaction temperature was 240°C, and the reaction time was 24 hours. 1.0 g of the SCM-36 zeolite prepared in Example I-1, 1.0 g of DMF, and 20 g of n-heptane were added to an autoclave with stirring, and ethylene was charged at 2.0 MPa. The temperature was raised to a preset temperature using a temperature-programmed heating jacket, and stirring was performed using a magnetic stirrer. The reaction continued at 240°C for 24 hours. The DMF conversion was 86%, the selectivity for pX was 94%, and the selectivity for polyalkylbenzenes, the major impurity, calculated based on gas-phase analysis of the reaction solution, was less than 1%.

[0205] Example II-2 n-Heptane was used as the reaction solvent, with a mass ratio of n-heptane to DMF of 20 and a mass ratio of DMF to catalyst of 1. The reaction temperature was 240°C, and the reaction time was 24 hours. 1.0 g of the SCM-36 zeolite prepared in Example I-2, 1.0 g of DMF, and 20 g of n-heptane were added to an autoclave with stirring, and ethylene was charged at 2.0 MPa. The temperature was raised to a preset temperature using a temperature-programmed heating jacket, and stirring was performed using a magnetic stirrer. The reaction continued at 240°C for 24 hours. The DMF conversion was 90%, the selectivity for pX was 94%, and the selectivity for polyalkylbenzenes, the major impurity, calculated based on gas-phase analysis of the reaction solution, was less than 1%.

[0206] Example II-3 n-Heptane was used as the reaction solvent, with a mass ratio of n-heptane to DMF of 20 and a mass ratio of DMF to catalyst of 1. The reaction temperature was 240°C, and the reaction time was 24 hours. 1.0 g of the SCM-36 zeolite prepared in Example I-3, 1.0 g of DMF, and 20 g of n-heptane were added to an autoclave with stirring, and ethylene was charged at 2.0 MPa. The temperature was raised to a preset temperature using a temperature-programmed heating jacket, and stirring was performed using a magnetic stirrer. The reaction continued at 240°C for 24 hours. The DMF conversion was 86%, the selectivity for pX was 95%, and the selectivity for polyalkylbenzenes, the major impurity, calculated based on gas-phase analysis of the reaction solution, was less than 1%.

[0207] Example II-4 n-Heptane was used as the reaction solvent, with a mass ratio of n-heptane to DMF of 20 and a mass ratio of DMF to catalyst of 1. The reaction temperature was 240°C, and the reaction time was 24 hours. 1.0 g of the SCM-36 zeolite prepared in Example I-4, 1.0 g of DMF, and 20 g of n-heptane were added to an autoclave with stirring, and ethylene was charged at 2.0 MPa. The temperature was raised to a preset temperature using a temperature-programmed heating jacket, and stirring was performed using a magnetic stirrer. The reaction continued at 240°C for 24 hours. The DMF conversion was 92%, the selectivity for pX was 95%, and the selectivity for polyalkylbenzenes, the major impurity, calculated based on gas-phase analysis of the reaction solution, was less than 1%.

[0208] Example II-5 In this example, n-heptane was used as the reaction solvent. The mass ratio of n-heptane to DMF was 20, and the mass ratio of DMF to catalyst was 1.5. The reaction temperature was 250°C, and the reaction time was 30 hours. 1.0 g of the SCM-36 zeolite catalyst prepared in Example I-1, 1.5 g of DMF, and 30 g of n-heptane were added to an autoclave with stirring, and ethylene was charged at 3.0 MPa. The temperature was raised to a preset temperature using a temperature-programmed heating jacket, and stirring was performed using a magnetic stirrer. The reaction continued at 250°C for 30 hours. The DMF conversion was 88%, the selectivity for pX was 96%, and the selectivity for polyalkylbenzenes, the major impurity, calculated based on gas-phase analysis of the reaction solution, was less than 1%.

[0209] Example II-6 In this example, n-heptane was used as the reaction solvent. The mass ratio of n-heptane to 2,5-hexanedione (HDO) was 20, and the mass ratio of HDO to catalyst was 1. The reaction temperature was 230°C, and the reaction time was 20 hours. 1.0 g of the SCM-36 zeolite catalyst prepared in Example I-1, 1 g of HDO, and 20 g of n-heptane were added to an autoclave with stirring, and ethylene was charged at 2.0 MPa. The temperature was raised to a preset temperature using a temperature-programmed heating jacket, and stirring was performed using a magnetic stirrer. The reaction continued at 230°C for 20 hours. The HDO conversion was 86%, the selectivity for pX was 95%, and the selectivity for polyalkylbenzenes, the major impurity, calculated based on gas-phase analysis of the reaction solution, was less than 1%.

[0210] Example II-7 In this example, n-hexane was used as the reaction solvent. The mass ratio of n-hexane to DMF was 30, and the mass ratio of DMF to catalyst was 2. The reaction temperature was 260°C, and the reaction time was 24 hours. 1.0 g of the SCM-36 zeolite catalyst prepared in Example I-1, 2.0 g of DMF, and 60 g of n-hexane were added to an autoclave with stirring, and ethylene was charged at 4.0 MPa. The temperature was raised to a preset temperature using a temperature-programmed heating jacket, and stirring was performed using a magnetic stirrer. The reaction continued at 260°C for 24 hours. The DMF conversion was 83%, the selectivity to pX was 94%, and the selectivity to polyalkylbenzenes, the major impurity, calculated based on gas-phase analysis of the reaction solution, was less than 1%.

[0211] Example II-8 In this example, n-hexane was used as the reaction solvent, with a mass ratio of n-hexane to DMF of 20 and a mass ratio of DMF to catalyst of 1.5. The reaction temperature was 240°C, and the reaction time was 30 hours. 1.0 g of the SCM-36 zeolite catalyst prepared in Example I-1, 1.5 g of DMF, and 30 g of n-hexane were added to an autoclave with stirring, and ethylene was charged at 2.0 MPa. The temperature was raised to a preset temperature using a temperature-programmed heating jacket, and stirring was performed using a magnetic stirrer. The reaction continued at 240°C for 30 hours. The DMF conversion was 88%, the selectivity to pX was 93%, and the selectivity to polyalkylbenzenes, the major impurity, calculated based on gas-phase analysis of the reaction solution, was less than 1%.

[0212] Example II-9 In this example, γ-valerolactone was used as the reaction solvent. The mass ratio of γ-valerolactone to HDO was 15, and the mass ratio of HDO to catalyst was 2. The reaction temperature was 270°C, and the reaction time was 28 hours. 1.0 g of the SCM-36 zeolite catalyst prepared in Example I-1, 2 g of HDO, and 30 g of γ-valerolactone were added to an autoclave with stirring, and ethylene was charged at 3.0 MPa. The temperature was raised to a preset temperature using a temperature-programmed heating jacket, and stirring was performed using a magnetic stirrer. The reaction continued at 270°C for 28 hours. The HDO conversion was 89%, the selectivity for pX was 95%, and the selectivity for polyalkylbenzenes, the major impurity, calculated based on gas-phase analysis of the reaction solution was less than 1%.

[0213] Example II-10 In this example, γ-valerolactone was used as the reaction solvent. The mass ratio of γ-valerolactone to DMF was 30, and the mass ratio of DMF to catalyst was 3. The reaction temperature was 270°C, and the reaction time was 32 hours. 1.0 g of the SCM-36 zeolite catalyst prepared in Example I-1, 3.0 g of DMF, and 90 g of γ-valerolactone were added to an autoclave with stirring, and ethylene was charged at 4.0 MPa. The temperature was raised to a preset temperature using a temperature-programmed heating jacket, and then stirring was performed using a magnetic stirrer. The reaction continued at 270°C for 32 hours. The DMF conversion was 85%, the selectivity for pX was 94%, and the selectivity for polyalkylbenzenes, the major impurity, calculated based on gas-phase analysis of the reaction solution was less than 1%.

[0214] Example II-11 In this example, toluene was used as the reaction solvent, with a mass ratio of toluene to HDO of 22 and a mass ratio of HDO to catalyst of 1. The reaction temperature was 250°C and the reaction time was 18 hours. 1.0 g of the SCM-36 zeolite catalyst prepared in Example I-1, 1 g of HDO, and 22 g of toluene were added to an autoclave with stirring, and ethylene was charged at 2.0 MPa. The temperature was raised to a preset temperature using a temperature-programmed heating jacket, and stirring was performed using a magnetic stirrer. The reaction continued at 250°C for 18 hours. The HDO conversion was 93%, the selectivity for pX was 95%, and the selectivity for polyalkylbenzenes, the major impurity, calculated from gas-phase analysis of the reaction solution was less than 1%.

[0215] Example II-12 In this example, toluene was used as the reaction solvent, with a mass ratio of toluene to HDO of 25 and a mass ratio of HDO to catalyst of 1.5. The reaction temperature was 260°C, and the reaction time was 24 hours. 1.0 g of the SCM-36 zeolite catalyst prepared in Example I-1, 1.5 g of HDO, and 37.5 g of toluene were added to an autoclave with stirring, and ethylene was charged at 4.0 MPa. The temperature was raised to a preset temperature using a temperature-programmed heating jacket, and stirring was performed using a magnetic stirrer. The reaction continued at 260°C for 24 hours. The HDO conversion was 90%, the selectivity for pX was 95%, and the selectivity for polyalkylbenzenes, the major impurity, calculated based on gas-phase analysis of the reaction solution, was less than 1%.

[0216] Example II-13 In this example, cyclohexane was used as the reaction solvent. The mass ratio of cyclohexane to DMF was 30, and the mass ratio of DMF to catalyst was 2. The reaction temperature was 250°C, and the reaction time was 40 hours. 1.0 g of the SCM-36 zeolite catalyst prepared in Example I-1, 2.0 g of DMF, and 60 g of cyclohexane were added to an autoclave with stirring, and ethylene was charged at 4.0 MPa. The temperature was raised to a preset temperature using a temperature-programmed heating jacket, and stirring was performed using a magnetic stirrer. The reaction continued at 250°C for 40 hours. The DMF conversion was 86%, the selectivity for pX was 96%, and the selectivity for polyalkylbenzenes, the major impurity, calculated based on gas-phase analysis of the reaction solution, was less than 1%.

[0217] Example II-14 In this example, cyclohexane was used as the reaction solvent. The mass ratio of cyclohexane to HDO was 20, and the mass ratio of HDO to catalyst was 2. The reaction temperature was 255°C, and the reaction time was 38 hours. 1.0 g of the SCM-36 zeolite catalyst prepared in Example I-1, 2.0 g of HDO, and 40.0 g of cyclohexane were added to an autoclave with stirring, and ethylene was charged at 4.0 MPa. The temperature was raised to a preset temperature using a temperature-programmed heating jacket, and stirring was performed using a magnetic stirrer. The reaction continued at 255°C for 38 hours. The HDO conversion was 87%, the selectivity for pX was 95%, and the selectivity for polyalkylbenzenes, the major impurity, calculated based on gas-phase analysis of the reaction solution, was less than 1%.

[0218] To provide a more intuitive explanation of the reaction conditions and results of Examples II-1 to II-14 above, various parameters and results are shown in Table II-1.

[0219] [Table 22] JPEG0007812918000023.jpg40169

[0220] Example II-15 n-Heptane was used as the reaction solvent, with a mass ratio of n-heptane to DMF of 20 and a mass ratio of DMF to catalyst of 1. The reaction temperature was 240°C, and the reaction time was 24 hours. 1.0 g of SCM-36 zeolite prepared in Example I-1, 1.0 g of DMF, and 20.0 g of n-heptane were added to an autoclave with stirring, and ethylene was charged at 2.0 MPa. The temperature was raised to a preset temperature using a temperature-programmed heating jacket, and then stirring was performed using a magnetic stirrer. The reaction continued at 240°C for 24 hours. The DMF conversion and pX selectivity were calculated based on gas-phase analysis of the reaction solution. The catalyst used was washed and dried before proceeding to the next reaction, and the reaction was repeated a total of four times. The results are shown in Figure 11. As a result, even after four reactions, the DMF conversion rate remained above 82%, the selectivity for pX remained at 92%, and the selectivity for polyalkylbenzenes, the main impurity, was less than 1%, demonstrating the good cycle stability of SCM-36 zeolite.

[0221] Example II-16 1) Production of SCM-36 zeolite The test was carried out with reference to Example I-1, but the ratios (molar ratios) of reactants and materials used were as follows: Al2O3 / SiO2=0.017 Tetramethylammonium hydroxide (A) / SiO2=0.20 n-Octyltrimethylammonium chloride (B) / SiO2=0.25 NaOH / SiO2=0.20 H2O / SiO2=30; After uniform mixing, the mixture was added to a stainless steel reactor and crystallized for 8 days at 155°C. After the crystallization was completed, the product was filtered, washed with water, dried in an oven at 120°C for 6 hours, and calcined in air at 550°C for 8 hours to obtain zeolite.

[0222] The XRD spectral data of the dried sample is shown in Table II-2, and the SEM image of the sample is similar to that shown in Figure 2.

[0223] [Table 23]

[0224] The specific surface area of ​​the resulting calcined product is 372 m 2 / g, external specific surface area is 149m 2 / g, total pore volume is 0.74 cm 3 / g, micropore volume is 0.09 cm 3 / g. The sample has a nanoflake morphology, with a crystal thickness of approximately 12 nanometers. The calcined sample has a SiO2 / Al2O3 molar ratio of 61.5, as measured by inductively coupled plasma optical emission spectroscopy (ICP).

[0225] The ammonia temperature-programmed desorption (NH3-TPD) spectrum of the obtained sample is shown in Figure 12. As a result, the total acid content was 470 μmol / g, and the weak acid content was 47%. The infrared spectrum of pyridine adsorption is shown in Figure 13, and the Lewis / Brønsted acid ratio was analyzed and measured to be 0.4.

[0226] 2) Preparation of p-xylene n-Heptane was used as the reaction solvent. 1.0 g of the SCM-36 zeolite prepared above, 1.0 g of DMF, and 20 ml of n-heptane were added to an autoclave with stirring, and the autoclave was filled with ethylene at 2.0 MPa. The temperature was raised to a preset temperature using a temperature-programmable heating jacket, and stirring was performed using a magnetic stirrer. The reaction was continued at 240°C for 24 hours. The DMF conversion was 93%, the selectivity for pX was 90%, and the selectivity for polyalkylbenzenes, the major impurity, calculated based on gas-phase analysis of the reaction mixture, was 3%.

[0227] Comparative Example II-1 A literature study (Microporous and Mesoporous Materials, 2018, 263, 11-20) reported the preparation of AlPO-17 zeolite. Phosphoric acid, aluminum isopropoxide, cyclohexylamine, and deionized water were homogeneously mixed to form a gel in a ratio of 1:0.9:1:50 (PO:Al:CHA (cyclohexylamine):HO). This gel was then hydrothermally crystallized at 190°C for 120 hours, washed, dried, and calcined in air at 550°C for 5 hours to produce AlPO-17 zeolite. The total acid content of this sample was 262 μmol / g, the weak acid content was 93%, and the Lewis / Brønsted acid ratio was 4.2.

[0228] n-Heptane was used as the reaction solvent. 1.0 g of the catalyst prepared above, 1.0 g of DMF, and 20 ml of n-heptane were added to an autoclave with stirring, and ethylene was charged at 2.0 MPa. The temperature was raised to a preset temperature using a temperature-programmed heating jacket, and then stirring was performed using a magnetic stirrer. The reaction continued at 240°C for 24 hours. Based on gas-phase analysis of the reaction mixture, the DMF conversion was calculated to be 67%, and the pX selectivity was 72%.

[0229] The preferred embodiments of the present application have been described in detail above. However, the present application is not limited to the specific details of the above embodiments. Within the technical idea of ​​the present application, several simple modifications can be made to the technical solutions of the present application, all of which fall within the protection scope of the present application.

[0230] Furthermore, it should be noted that each of the specific technical features described in the above specific embodiments can be combined in any appropriate manner unless there is a contradiction, and in order to avoid unnecessary repetition, the present application does not describe each possible combination individually.

[0231] Furthermore, various different embodiments of the present application can be arbitrarily combined, and these should also be considered as the contents disclosed in the present application unless they are contrary to the concept of the present application. [Brief explanation of the drawings]

[0232] [Figure 1] FIG. 1 shows the X-ray diffraction (XRD) spectrum of the zeolite obtained in Example I-1; [Figure 2] FIG. 2 is a scanning electron microscope (SEM) image of the zeolite obtained in Example I-1; [Figure 3] FIG. 3 is a transmission electron microscope (TEM) image of the zeolite obtained in Example I-1; [Figure 4] FIG. 4 shows the ammonia temperature-programmed desorption (NH3-TPD) spectrum of the zeolite obtained in Example I-1; [Figure 5] FIG. 5 shows the pyridine adsorption infrared (Py-FTIR) spectrum of the zeolite obtained in Example I-1; [Figure 6] FIG. 6 shows the XRD spectrum of the zeolite obtained in Example I-2; [Figure 7] FIG. 7 shows an SEM image of the zeolite obtained in Example I-3; [Figure 8] Figure 8 shows the XRD spectrum of the sample obtained in Comparative Example I-1; [Figure 9] Figure 9 shows the XRD spectrum of the sample obtained in Comparative Example I-3; [Figure 10] Figure 10 shows the XRD spectrum of the sample obtained in Comparative Example I-4; [Figure 11] FIG. 11 is a graph of 2,5-dimethylfuran conversion and p-xylene selectivity under recycle conditions for SCM-36 zeolite in Example II-15; [Figure 12] Figure 12 shows the NH3-TPD spectrum of the zeolite obtained in Example II-16; [Figure 13] FIG. 13 shows the Py-FTIR spectrum of the zeolite obtained in Example II-16.

Claims

1. A silicon-aluminum zeolite, said zeolite having a silicon / aluminum ratio n≧5, and an X-ray diffraction spectrum of said zeolite exhibiting the relative intensities of diffraction peaks characteristic of the following table: Table 1

2. 2. The silicon-aluminum zeolite of claim 1, wherein the X-ray diffraction spectrum of the zeolite also exhibits the relative intensity characteristics of the diffraction peaks shown in any one row of the following table: Table 2

3. 3. The silicon-aluminum zeolite of claim 2, wherein the X-ray diffraction spectrum of the zeolite also exhibits the relative intensity characteristics of the diffraction peaks shown in any one row of the following table: Table 3

4. The silicon-aluminum zeolite according to any one of claims 1 to 3, having at least one of the following characteristics: Specific surface area is 300m ２ / g~700m ２ / g; External specific surface area is 50m ２ / g to 300m ２ / g; Total pore volume is 0.20 cm ３ / g ~ 1.50 cm ３ / g; Micropore volume is 0.05 cm ３ / g ~ 0.35 cm ３ / g; The total acid content is 400 μmol / g to 1200 μmol / g, and the weak acid content is 40% or more; and, The Lewis acid / Bronsted acid ratio is 0.1 to 3.

8.

5. 4. The silicon-aluminum zeolite according to claim 1, wherein the zeolite has a nanoflake crystalline morphology with a crystal thickness of less than 30 nanometers.

6. 4. The silicon-aluminum zeolite according to claim 1, wherein the zeolite further contains at least one element M selected from the group consisting of titanium, boron, zirconium, tin, and iron.

7. 1) A method for producing a zeolite by crystallizing a mixture containing a silicon source, an aluminum source, an organic structure-directing agent (A), an organic structure-directing agent (B), an alkali source, and water, or 1) crystallizing a mixture containing a silicon source, an aluminum source, an organic structure directing agent (A), an organic structure directing agent (B), an alkali source, and water to obtain a zeolite; and 2) calcining the zeolite obtained in step 1); 2. The method for producing a silicon-aluminum zeolite according to claim 1, wherein the organic structure-directing agent (A) is selected from a tetramethylammonium compound, and the organic structure-directing agent (B) is selected from a C6-16 alkylpyridinium compound, an n-octyltrimethylammonium compound, or a combination thereof.

8. In the mixture of step 1), the silicon source (SiO ２ calculated based on the aluminum source (Al ２ O ３ 8. The method according to claim 7, wherein the molar ratio of the organic structure-directing agent (A), the organic structure-directing agent (B), the alkali source, and water is 1:(0.01 to 0.20):(0.05 to 0.80):(0.05 to 0.80):(0.05 to 0.50):(8 to 80).

9. 9. The method according to claim 7 or 8, wherein the crystallization temperature in step 1) is 120°C to 200°C; and the crystallization time is 1 day to 15 days.

10. The organic structure directing agent (A) is selected from the group consisting of tetramethylammonium hydroxide, tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium iodide, or a combination thereof; and / or 9. The method of claim 7, wherein the organic structure-directing agent (B) is selected from the group consisting of hexadecylpyridine bromide, tetradecylpyridine bromide, dodecylpyridine bromide, decylpyridine bromide, hexadecylpyridine chloride, tetradecylpyridine chloride, hexadecylpyridine hydroxide, n-octyltrimethylammonium chloride, n-octyltrimethylammonium bromide, n-octyltrimethylammonium hydroxide, or a combination thereof.

11. the silicon source is selected from the group consisting of silicic acid, silica gel, silica sol, tetraethyl silicate, sodium silicate, or a combination thereof; the aluminum source is selected from the group consisting of aluminum hydroxide, aluminum oxide, aluminates, aluminum salts, tetraalkoxyaluminum, or combinations thereof; and / or 9. The method of claim 7 or 8, wherein the alkaline source is selected from the group consisting of inorganic alkalis having an alkali metal as a cation, inorganic alkalis having an alkaline earth metal as a cation, or a combination thereof.

12. 9. The method of claim 7 or 8, wherein the mixture from step 1) further comprises a source of an element M selected from the group consisting of titanium, boron, zirconium, tin, iron, or combinations thereof.

13. A zeolite composition comprising the silicon-aluminum zeolite of claim 1 and a binder.

14. Use of the silicon-aluminum zeolite according to any one of claims 1 to 3 or the zeolite composition according to claim 13 as an adsorbent, catalyst or catalyst support.

15. A method for preparing p-xylene, comprising the step of contacting and reacting a feedstock comprising 2,5-dimethylfuran, 2,5-hexanedione, or a combination thereof with ethylene in the presence of a catalyst comprising or consisting of the silicon-aluminum zeolite of claim 1.

16. 16. The method of claim 15, having at least one of the following features: The reaction is carried out in the presence of an organic solvent selected from the group consisting of n-hexane, n-heptane, γ-valerolactone, tetrahydrofuran, toluene, cyclohexane, or a combination thereof; the mass ratio of the feedstock to the catalyst is 0.6 to 30:1; and The mass ratio of the organic solvent to the raw materials is 8 to 60:

1.

17. The reaction conditions are The reaction temperature is 160°C to 340°C; The reaction time is 6 hours to 64 hours; and The method according to claim 15 or 16, wherein the reaction pressure is 1 MPa to 8 MPa.

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