Flaky SCM-44 molecular sieve as well as preparation method and application thereof

Abstract

The invention provides a flaky SCM-44 molecular sieve as well as a preparation method and application thereof. The chemical composition of the flaky SCM-44 molecular sieve is mSiO2.nGeO2.xXO1.5, X is a trivalent skeleton element, the molar ratio m: n of SiO2 to GeO2 is (2-25): 1, and the ratio (m + n): x of the sum of the molar numbers of SiO2 and GeO2 to the molar number of XO1.5 is (15-30): 1. The preparation method of the SCM-44 molecular sieve is simple, the organic template agent is cheap and easy to obtain, the cost is low, and the obtained SCM-44 molecular sieve is flaky, has the characteristics of large specific surface area and large micropore volume, and has more catalytic and adsorption active sites and more excellent performance.

Description

Technical Field

[0001] The invention belongs to the field of porous materials, and in particular relates to a sheet-like SCM-44 molecular sieve and a preparation method and application thereof. Background Art

[0002] Zeolite molecular sieve is a kind of porous crystalline material with regular molecular size pore structure, strong acidity and high hydrothermal stability. It is widely used in catalysis, adsorption and ion exchange and plays an irreplaceable role. The framework of molecular sieve is usually composed of coordinated tetrahedrons (TO4) connected by common vertices (generally oxygen atoms). For zeolite molecular sieve, the tetrahedrons in the framework are mainly SiO4 tetrahedrons and AlO4 tetrahedrons. These two tetrahedrons can be replaced by other tetrahedrons to form molecular sieves or molecular sieve-like structures with different framework structures. For example, AlO4 tetrahedron can be replaced by GaO4 or ZnO4 tetrahedron, thus forming the framework of heteroatom molecular sieve together with SiO4 tetrahedron; Ge and Si have similar coordination properties and can also form tetrahedral coordination structures. Through the connection of GeO4 and SiO4, a large number of new germanium-containing molecular sieves or molecular sieve-like structures can be formed. Several types of germanosilicate molecular sieves that have been studied include UTL (US 7074385), BEC (US 6896869), STW (Nature Mater., 2008, 7, 381-385), etc. The research group of Professor Corma of the Polytechnic University of Valencia, Spain, reported a new molecular sieve ITQ-27 (WO 2006055305 A2). This molecular sieve has an IWV framework topology and has an opening size of 2.37 mm in the

[001] and

[011] directions. The 12-membered ring channel forms a two-dimensional 12×12-membered ring channel system. The IWV molecular sieve framework elements are generally silicon and aluminum, which have acidic active centers and can be used for acid-catalyzed reactions. The introduction of germanium elements into the IWV molecular sieve framework can further enrich the types of IWV molecular sieves. Summary of the invention

[0003] The purpose of the present invention is to provide a sheet-like SCM-44 molecular sieve and its preparation method and application. The SCM-44 molecular sieve of the present invention contains silicon, germanium and trivalent skeleton elements, and has a thin sheet morphology, many active sites, high specific surface area, large micropore volume, and excellent adsorption and catalytic performance. The method for preparing the SCM-44 molecular sieve of the present invention is simple, and the organic template agent is cheap and easy to obtain, and the cost is low.

[0004] To achieve the above object, the present invention adopts the following technical solution:

[0005] In the first aspect, the present invention provides a sheet-like SCM-44 molecular sieve, the chemical composition of which is m SiO2·n GeO2·xXO1.5 , where X is a trivalent skeleton element, the molar ratio of SiO2 to GeO2 is m:n=(2-25):1, and the sum of the molar numbers of SiO2 and GeO2 is equal to XO 1.5 The molar ratio (m+n): x=(15-30):1.

[0006] In the present invention, the molar ratio m / n of SiO2 and GeO2 satisfies: 2≤m / n≤25, for example, m:n can be 2:1, 2.5:1, 3:1, 5:1, 8:1, 10:1, 12:1, 15:1, 18:1, 20:1, 22:1, 25:1 or any value therebetween, preferably 2.5≤m / n≤20, more preferably 3.5≤m / n≤16.

[0007] In the present invention, the sum of the molar numbers of SiO2 and GeO2 is equal to the molar number of XO2. 1.5 The molar ratio (m+n) / x satisfies: 15≤(m+n) / x≤30, for example, (m+n):x can be 15:1, 18:1, 20:1, 22:1, 25:1, 28:1, 30:1 or any value therebetween, preferably 18≤(m+n) / x≤25.

[0008] In some embodiments, in the SCM-44 molecular sieve, the sum of the molar numbers of SiO2 and GeO2 is 1, that is, m+n=1.

[0009] In some embodiments, the sum of the moles of SiO2 and GeO2 is equal to the moles of the XO 1.5 The molar ratio of is 15≤1 / x≤30, for example, 1:x can be 15:1, 18:1, 20:1, 22:1, 25:1, 28:1, 30:1 or any value therebetween, preferably 18≤1 / x≤25.

[0010] In some embodiments, X is selected from at least one of Group IIIA elements, Group VIII elements, Group VIB elements, or Group IIIB elements, preferably at least one of aluminum, boron, iron, gallium, indium, and chromium, and more preferably at least one of aluminum and boron.

[0011] In some embodiments, Si in the SCM-44 molecular sieve is replaced by at least one non-silicon tetravalent framework element Y, and the non-silicon tetravalent framework element Y is selected from tin, titanium, zirconium and hafnium. In some embodiments, no more than 10wt% of the Si element in the molecular sieve is replaced by at least one non-silicon tetravalent framework element Y. In some embodiments, 1-9wt% of the Si element in the molecular sieve is replaced by at least one non-silicon tetravalent framework element Y.

[0012] The present invention partially replaces the Si element in the SCM-44 molecular sieve framework with a non-silicon tetravalent element Y, and then introduces one or more other elements into the framework to generate different catalytic active centers, thereby meeting the needs of different catalytic reactions.

[0013] In some embodiments, the flaky SCM-44 molecular sieve has a flaky layer thickness of 20 to 500 nm.

[0014] In some embodiments, the specific surface area of ​​the sheet-like SCM-44 molecular sieve is greater than 500 m 2 / g.

[0015] In some embodiments, the micropore volume of the sheet-like SCM-44 molecular sieve is greater than 0.20 cm 3 / g.

[0016] The SCM-44 molecular sieve of the present invention has an IWV framework topology structure and is a novel molecular sieve containing germanium and has a flaky structure, thus enriching the types of IWV molecular sieves.

[0017] In some embodiments, the X-ray diffraction pattern of the flaky SCM-44 molecular sieve includes characteristic peaks as shown in Table 1 below:

[0018] Table 1

[0019]

[0020]

[0021] In the present invention, in the X-ray diffraction pattern, vw, w, m, s, and vs represent the diffraction peak intensity, vw means very weak, w means weak, m means medium, s means strong, and vs means very strong; generally speaking, vw means less than 5%, w means 5%-20%, m means 20%-40% (including 20% ​​and 40%), s means 40%-70%, and vs means greater than 70% (including 70%).

[0022] Since the strength is affected by many factors, the data in Table 1 are expressed as the interplanar spacing of SCM-44 molecular sieve at 2θ (°) of 6.30 ± 0.2. is 14.02±0.55, and the relative intensity (%) (I / I0)×100 is s-vs (40%-100%). Similarly, the method of expressing the table is well known to those skilled in the art, and the present invention will not be described one by one here.

[0023] In a second aspect, the present invention provides a method for preparing the flaky SCM-44 molecular sieve described in the first aspect, comprising the following steps:

[0024] A mixed solution including a silicon source, a germanium source, an optional non-silicon tetravalent framework element Y source, a trivalent framework element X source, a fluorine source, a structure directing agent R and water is subjected to a crystallization reaction to obtain a flaky SCM-44 molecular sieve.

[0025] The present invention does not specifically limit the preparation method of the mixed solution. For example, a germanium source and a trivalent skeleton element X source may be mixed first, and then a silicon source and an optional non-silicon tetravalent skeleton element Y source are added in sequence, and then a fluorine source and water are added to obtain the mixed solution.

[0026] In some embodiments, the molar number of the silicon source is calculated as SiO2, and the molar number of the germanium source is calculated as GeO2. In the mixed solution, the molar ratio of SiO2 to GeO2 is (2-25):1, for example, 2:1, 2.5:1, 3:1, 5:1, 8:1, 10:1, 12:1, 15:1, 18:1, 20:1, 22:1, 25:1 or any value therebetween, preferably (2.5-20:1).

[0027] In some embodiments, the molar number of the silicon source is calculated as SiO2, and the molar number of the germanium source is calculated as GeO2. In the mixed solution, the sum of the molar numbers of SiO2 and GeO2 is 1.

[0028] In some embodiments, the molar number of the silicon source is calculated as SiO2, and the molar number of the Y source is calculated as the corresponding oxide YO2. In the mixed solution, the molar ratio of YO2 to SiO2 is (0-0.1):1, for example, 0.01:1, 0.02:1, 0.03:1, 0.04:1, 0.05:1, 0.06:1, 0.07:1, 0.08:1, 0.09:1, 0.1:1 or any value therebetween, preferably (0.01-0.09):1.

[0029] In some embodiments, the molar number of the silicon source is calculated as SiO2, the molar number of the germanium source is calculated as GeO2, and the molar number of the X source is calculated as X2O3. In the mixed solution, the ratio of the sum of the molar numbers of SiO2 and GeO2 to the molar number of X2O3 is (30-60):1, for example, 30:1, 33:1, 36:1, 40:1, 45:1, 48:1, 50:1, 52:1, 55:1, 58:1, 60:1 or any value therebetween, preferably (36-50:1).

[0030] In some embodiments, the molar number of the silicon source is calculated as SiO2, the molar number of the germanium source is calculated as GeO2, the molar number of the X source is calculated as X2O3, and the molar number of the Y source is calculated as the corresponding oxide YO2. In the mixed solution, the ratio of the sum of the molar numbers of SiO2, GeO2 and YO2 to the molar number of X2O3 is (30-60):1, for example 30:1, 33:1, 36:1, 40:1, 45:1, 48:1, 50:1, 52:1, 55:1, 58:1, 60:1 or any value therebetween, preferably (36-50:1).

[0031] In some embodiments, the molar number of the silicon source is calculated as SiO2, the molar number of the germanium source is calculated as GeO2, and the molar number of the fluorine source is calculated as F. In the mixed solution, the molar ratio of the sum of the molar numbers of SiO2 and GeO2 to F is 1:(0.2-4), for example, 1:0.2, 1:0.3, 1:0.35, 1:0.5, 1:0.8, 1:1.0, 1:1.2, 1:1.5, 1:2, 1:2.5, 1:2.8, 1:3, 1:3.5, 1:4 or any value therebetween, preferably 1:(0.35-2.5).

[0032] In some embodiments, the molar number of the silicon source is calculated as SiO2, the molar number of the germanium source is calculated as GeO2, the molar number of the Y source is calculated as the corresponding oxide YO2, and the molar number of the fluorine source is calculated as F. In the mixed solution, the molar ratio of the sum of the molar numbers of SiO2, GeO2 and YO2 to F is 1:(0.2-4), for example 1:0.2, 1:0.3, 1:0.35, 1:0.5, 1:0.8, 1:1.0, 1:1.2, 1:1.5, 1:2, 1:2.5, 1:2.8, 1:3, 1:3.5, 1:4 or any value therebetween, preferably 1:(0.35-2.5).

[0033] In some embodiments, the molar number of the silicon source is calculated as SiO2, and the molar number of the germanium source is calculated as GeO2. In the mixed solution, the molar ratio of the sum of the molar numbers of SiO2 and GeO2 to the structure directing agent R is 1:(0.15-4), for example, 1:0.15, 1:0.2, 1:0.35, 1:0.5, 1:0.8, 1:1.0, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4 or any value therebetween, preferably 1:(0.35-2), and more preferably 1:(0.5-1.5).

[0034] In some embodiments, the molar number of the silicon source is calculated as SiO2, the molar number of the germanium source is calculated as GeO2, and the molar number of the Y source is calculated as the corresponding oxide YO2. In the mixed solution, the molar ratio of the sum of the molar numbers of SiO2, GeO2 and YO2 to the structure directing agent R is 1:(0.15-4), for example, 1:0.15, 1:0.2, 1:0.35, 1:0.5, 1:0.8, 1:1.0, 1:1.2, 1:1.5, 1:1.8, 1:2, 1:2.5, 1:3, 1:3.5, 1:4 or any value therebetween, preferably 1:(0.35-2), and more preferably 1:(0.5-1.5).

[0035] In some embodiments, the molar number of the silicon source is calculated as SiO2, and the molar number of the germanium source is calculated as GeO2. In the mixed solution, the molar ratio of the sum of the molar numbers of SiO2 and GeO2 to water is 1:(8-35), for example, 1:8, 1:12, 1:15, 1:18, 1:20, 1:22, 1:25, 1:28, 1:35 or any value therebetween, preferably 1:(10-25).

[0036] In some embodiments, the molar number of the silicon source is calculated as SiO2, the molar number of the germanium source is calculated as GeO2, and the molar number of the Y source is calculated as the corresponding oxide YO2. In the mixed solution, the molar ratio of the sum of the molar numbers of SiO2, GeO2 and YO2 to water is 1:(8-35), for example 1:8, 1:12, 1:15, 1:18, 1:20, 1:22, 1:25, 1:28, 1:35 or any value therebetween, preferably 1:(10-25).

[0037] In some preferred embodiments, the molar number of the silicon source is calculated as SiO2, the molar number of the germanium source is calculated as GeO2, the molar number of the X source is calculated as X2O3, and the molar number of the fluorine source is calculated as F. In the mixed solution, the molar ratio of the structure directing agent R, SiO2, GeO2, X2O3, F and water is (0.15-4):(0.667-0.962):(0.038-0.333):(0.0167-0.0333):(0.2-4):(8-35).

[0038] In some more preferred embodiments, the molar number of the silicon source is calculated as SiO2, the molar number of the germanium source is calculated as GeO2, the molar number of the X source is calculated as X2O3, and the molar number of the fluorine source is calculated as fluorine. In the mixed solution, the molar ratio of the structure directing agent R, SiO2, GeO2, X2O3, F and water is (0.35-2):(0.714-0.952):(0.048-0.286):(0.02-0.0278):(0.35-2.5):(10-25).

[0039] In some embodiments, the silicon source is at least one selected from the group consisting of water glass, silica sol, solid silica gel, fumed silica, amorphous silica, diatomaceous earth, zeolite molecular sieves, and tetraalkoxysilane.

[0040] In some embodiments, the germanium source is selected from at least one of germanium oxide, germanium nitrate, and tetraalkoxygermanium.

[0041] In some embodiments, the non-silicon tetravalent skeleton element Y source is selected from at least one of a tin source, a titanium source, a zirconium source, and a hafnium source. In the present invention, the tin source, the titanium source, the zirconium source, and the hafnium source can be conventional tin-containing compounds, titanium-containing compounds, zirconium-containing compounds, or hafnium-containing compounds in the art, respectively.

[0042] In some preferred embodiments, the tin source is selected from at least one of tin tetrachloride, stannous chloride, alkyl tin, alkoxy tin and organic tin esters. In some preferred embodiments, the titanium source is selected from at least one of tetraalkyl titanates (e.g., tetramethyl titanate, tetraethyl titanate, tetrapropyl titanate, tetra-n-butyl titanate), titanium tetrachloride, hexafluorotitanic acid, titanium sulfate and their hydrolyzates. In some preferred embodiments, the zirconium source is selected from at least one of zirconium nitrate, zirconium tetrachloride, zirconium oxide and alkoxy zirconium. In some preferred embodiments, the hafnium source is selected from at least one of hafnium oxide and hafnium sulfate.

[0043] Preferably, the trivalent skeleton element X source is selected from at least one of an aluminum source, a boron source, an iron source, a gallium source, an indium source and a chromium source. In the present invention, the aluminum source, the boron source, the iron source, the gallium source, the indium source and the chromium source can be conventional aluminum-containing compounds, boron-containing compounds, iron-containing compounds, gallium-containing compounds, indium-containing compounds or chromium-containing compounds in the art.

[0044] In some preferred embodiments, the aluminum source is selected from at least one of aluminum sulfate, sodium aluminate, aluminum nitrate, aluminum chloride, pseudo-boehmite, aluminum oxide, aluminum hydroxide, silica-aluminum zeolite molecular sieve, aluminum carbonate, elemental aluminum, aluminum isopropoxide and aluminum acetate. In some preferred embodiments, the boron source is selected from at least one of boric acid, sodium tetraborate, amorphous boron oxide, potassium borate, sodium metaborate, ammonium tetraborate and organic boron esters. In some preferred embodiments, the iron source is selected from at least one of ferric sulfate, ferric nitrate, iron halide (such as ferric chloride), ferrocene and ferric citrate. In some preferred embodiments, the gallium source is selected from at least one of gallium oxide and gallium nitrate. In some preferred embodiments, the indium source is selected from at least one of indium oxide and indium nitrate. In some preferred embodiments, the chromium source is selected from at least one of chromium oxide, chromium chloride and chromium nitrate.

[0045] In some embodiments, the fluorine source is selected from at least one of hydrofluoric acid, ammonium fluoride, sodium fluoride and potassium fluoride, preferably at least one of hydrofluoric acid and ammonium fluoride.

[0046] In some embodiments, the structure directing agent R is selected from a compound containing a 1,1,3,5-tetraalkylpiperidinium ion or a compound having a structure shown in Formula I,

[0047]

[0048] In Formula I, R1 to R4 are each independently selected from H and C 1-6 The alkyl group is preferably hydrogen, methyl, ethyl, propyl, isopropyl, butyl, isobutyl and tert-butyl.

[0049] In some embodiments, the anion X- in the structure directing agent is selected from halogen ions and hydroxide ions, preferably Cl-, Br - ,I - and OH-, more preferably OH-.

[0050] In some preferred embodiments, the structure directing agent R is 1,1,3,5-tetramethylpiperidinium hydroxide (1,1,3,5-TMPOH).

[0051] In some embodiments, the temperature of the crystallization reaction is 100-200°C, preferably 110-190°C, and more preferably 155-175°C.

[0052] In some embodiments, the crystallization reaction time is 72-600 hours, preferably 96-480 hours, and more preferably 120-360 hours.

[0053] The crystallization reaction described in the present invention can be carried out under dynamic or static conditions. In the present invention, the results of static or dynamic crystallization are basically the same, so the embodiments of the present invention do not specifically describe static or dynamic.

[0054] In the preparation method of the sheet-like molecular sieve of the present invention, after the crystallization step is completed, the molecular sieve can also be separated from the obtained reaction mixture as a product by any conventionally known separation method, thereby obtaining the sheet-like SCM-44 molecular sieve of the present invention. As the separation method, for example, operations such as filtering, washing and drying the obtained reaction mixture can be cited. The filtration, washing and drying can be carried out in any conventional manner known in the art. For example, as the filtration, for example, the obtained reaction mixture can be simply filtered. As the washing, for example, washing with deionized water can be cited. As the drying temperature, for example, 40-250°C, preferably 60-150°C, can be cited, and as the drying time, for example, 8-30 hours, preferably 10-20 hours can be cited. The drying can be carried out at normal pressure or under reduced pressure.

[0055] In the preparation method of the flaky molecular sieve of the present invention, as required, the molecular sieve obtained according to the preparation method of the flaky molecular sieve can also be calcined to remove the organic template and possible moisture, etc., thereby obtaining the calcined flaky SCM-44 molecular sieve. The calcination can be carried out in any conventional manner known in the art, such as the calcination temperature is generally 300-800°C, preferably 400-650°C, and the calcination time is generally 1-10 hours, preferably 3-6 hours. In addition, the calcination is generally carried out in an oxygen-containing atmosphere, such as air or oxygen atmosphere.

[0056] In a third aspect, the present invention provides a molecular sieve composition, which comprises the flaky SCM-44 molecular sieve described in the first aspect of the present invention, and a binder.

[0057] The sheet-like SCM-44 molecular sieve of the present invention can be used in combination with other materials to obtain a molecular sieve composition. Examples of the other materials include active materials such as synthetic zeolites and natural zeolites, and inactive materials (generally referred to as binders) such as clay, clay, silica gel, aluminum oxide, silicon oxide and magnesium oxide. These other materials can be used alone or in combination in any proportion. As the amount of the other materials, the conventional amount used in the art can be directly referred to without particular limitation.

[0058] In a fourth aspect, the present invention provides use of the SCM-44 molecular sieve described in the first aspect or the molecular sieve composition described in the third aspect of the present invention in catalytic reaction, adsorption or ion exchange.

[0059] The SCM-44 molecular sieve of the present invention or the molecular sieve composition containing the SCM-44 molecular sieve can be used as an adsorbent, for example, to separate at least one component from a mixture of multiple components in a gas phase or a liquid phase. Accordingly, the at least one component can be partially or substantially completely separated from the mixture of various components, for example, by contacting the mixture with the SCM-44 molecular sieve or the molecular sieve composition containing the SCM-44 molecular sieve, and selectively adsorbing this component. In addition, the SCM-44 molecular sieve of the present invention or the molecular sieve composition containing the SCM-44 molecular sieve can also be used as a catalyst, especially a catalyst in an organic compound conversion reaction.

[0060] Compared with the prior art, the present invention has the following beneficial effects:

[0061] 1. The SCM-44 molecular sieve of the present invention is a new type of molecular sieve containing germanium, and its framework topology structure is IWV, which enriches the types of IWV molecular sieves.

[0062] 2. The SCM-44 molecular sieve of the present invention has a flaky structure, a high specific surface area and a large micropore volume.

[0063] 3. The SCM-44 molecular sieve of the present invention contains silicon, germanium and trivalent skeleton elements. The various skeleton elements can further increase the catalytic and adsorption active sites and improve the catalytic and adsorption performance of the molecular sieve.

[0064] 4. The present invention uses a single template to prepare a novel sheet-like SCM-44 molecular sieve, with a simple process and low production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The accompanying drawings are used to provide further understanding of the present application and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present application, but do not constitute a limitation to the present application.

[0066] Figure 1 This is the XRD spectrum of the SCM-44 molecular sieve prepared in Example 1.

[0067] Figure 2 This is a SEM image of the SCM-44 molecular sieve prepared in Example 1.

[0068] Figure 3 This is the nitrogen adsorption-desorption isotherm of the SCM-44 molecular sieve prepared in Example 1.

[0069] Figure 4 This is the XRD spectrum of the SCM-44 molecular sieve prepared in Example 2.

[0070] Figure 5This is a SEM image of the SCM-44 molecular sieve prepared in Example 2. DETAILED DESCRIPTION

[0071] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and drawings. The specific embodiments described herein are only used to explain the present invention and are not intended to constitute any limitation to the present invention.

[0072] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0073] In this paper, the structure of the molecular sieve is determined by an X-ray diffraction spectrum (XRD), which is measured by an X-ray powder diffractometer using a Cu-Kα ray source with a Kα1 wavelength of λ = 1.5405980 angstroms. Nickel filter.

[0074] In the present invention, an X'Pert PRO X-ray powder diffraction (XRD) instrument of PANalytical Company of the Netherlands is used, with an operating voltage of 40 kV, a current of 40 mA, and a scanning range of 5 to 40°.

[0075] In the present invention, the scanning electron microscope (SEM) images were obtained by a Japanese HITACHI S4800 field emission scanning electron microscope, and the test conditions were as follows: voltage 3 kV, current 50 mA.

[0076] In the present invention, the “C 1-6 " means the number of carbon atoms is 1-6, for example, the number of carbon atoms is 1, 2, 3, 4, 5 or 6; "C 1-6 The term "alkyl" refers to an alkyl group having 1 to 6 carbon atoms, including but not limited to methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, isopentyl, cyclopentyl, hexyl, isohexyl, cyclohexyl, and the like.

[0077] Unless otherwise specified, all percentages, parts, ratios, etc. mentioned in this specification are based on weight, unless the weight basis does not conform to the common understanding of those skilled in the art.

[0078] Unless otherwise specified, the reagents used in the following examples of the present invention can be obtained through commercial channels.

[0079] Example 1

[0080] Dissolve 0.698g of germanium oxide and 0.408g of aluminum isopropoxide in 15.82g of 1,1,3,5-TMPOH aqueous solution (20wt%), slowly add 6.934g of tetraethyl orthosilicate (TEOS), stir at room temperature, and after complete hydrolysis, open the container and stir overnight to evaporate ethanol, isopropanol and part of the water, add 1g of hydrofluoric acid (40wt%), stir evenly, and adjust the amount of water until the reaction mixture reaches the following molar composition:

[0081] 0.5(1,1,3,5-TMPOH):0.833SiO2:0.167GeO2:0.025Al2O3:0.5HF:16H2O

[0082] The above mixture was placed in a crystallization kettle with a polytetrafluoroethylene liner and placed in a 175°C oven for crystallization for 288 hours. The solid after the reaction was filtered, washed with distilled water, and dried at 100°C to obtain a raw powder solid. The raw powder solid was placed in a muffle furnace and calcined at 550°C for 5 hours to obtain the final product. The XRD spectrum is as follows: Figure 1 The XRD spectrum data are shown in Table 2, and the SEM data are shown in Figure 2 As shown by Figure 2 It can be seen that SCM-44 molecular sieve is a flaky crystal with a flaky layer thickness of 25nm. Figure 3 As shown by Figure 3 It can be seen that SCM-44 molecular sieve has a type I isotherm and a specific surface area of ​​630m 2 / g, micropore volume is 0.24cm 3 / g. The composition (molar ratio) of the raw materials for synthesizing the molecular sieve is shown in Table 6.

[0083] Table 2

[0084]

[0085]

[0086] Example 2

[0087] Dissolve 0.492g of germanium oxide and 0.408g of aluminum isopropoxide in 19g of 1,1,3,5-TMPOH aqueous solution (20wt%), slowly add 7.342g of tetraethyl orthosilicate (TEOS), stir at room temperature, and after complete hydrolysis, open the container and stir overnight to volatilize ethanol, isopropanol and part of the water, add 1.2g of hydrofluoric acid (40wt%), stir evenly, and adjust the amount of water until the reaction mixture reaches the following molar composition:

[0088] 0.6(1,1,3,5-TMPOH):0.882SiO2:0.118GeO2:0.025Al2O3:0.6HF:12.5H2O

[0089] The above mixture was placed in a crystallization kettle with a polytetrafluoroethylene liner and placed in a 170°C oven for crystallization for 336 hours. The solid after the reaction was filtered, washed, dried, and calcined to obtain the final product. The XRD spectrum is as follows: Figure 4 As shown by Figure 4 It can be seen that the product is SCM-44 molecular sieve, the spectrum data is shown in Table 3, and the SEM photo is shown in Figure 5 As shown by Figure 5 It can be seen that the SCM-44 molecular sieve is a plate-like crystal with a plate thickness of 40 nm. The composition of the raw materials for synthesizing the molecular sieve is shown in Table 6.

[0090] Table 3

[0091]

[0092]

[0093] Example 3

[0094] 0.38g of germanium oxide and 0.326g of aluminum isopropoxide were dissolved in 23.74g of 1,1,3,5-TMPOH aqueous solution (20wt%), 7.564g of tetraethyl orthosilicate (TEOS) were slowly added, and stirred at room temperature. After the hydrolysis was complete, the container was opened and stirred overnight to evaporate ethanol, isopropanol and part of the water, 1g of hydrofluoric acid (40wt%) and 1g of ammonium fluoride solution (37wt%) were added, and the amount of water was adjusted after stirring evenly until the reaction mixture reached the following molar composition:

[0095] 0.75(1,1,3,5-TMPOH):0.909SiO2:0.091GeO2:0.02Al2O3:0.5HF:0.25NH4F:20H2O

[0096] The above mixture was placed in a crystallization kettle with a polytetrafluoroethylene liner and placed in a 170°C oven for crystallization for 216 hours. The solid after the reaction was filtered, washed, dried, and calcined to obtain the final SCM-44 molecular sieve product. The XRD spectrum was consistent with Figure 1 The composition of the raw materials for synthesizing the molecular sieve is shown in Table 6.

[0097] Example 4

[0098] 0.246g of germanium oxide and 0.104g of pseudo-boehmite (containing 70wt% Al2O3) were dissolved in 31.64g of 1,1,3,5-TMPOH aqueous solution (20wt%), 5.647 silica sol (Ludox HS-40, containing 40wt% SiO2) was slowly added, and stirred at room temperature. The container was left open and stirred overnight to evaporate part of the water, and 4.8g of ammonium fluoride solution (37wt%) was added. After stirring evenly, the amount of water was adjusted until the reaction mixture reached the following molar composition:

[0099] 1.0(1,1,3,5-TMPOH):0.941SiO2:0.059GeO2:0.018Al2O3:1.2NH4F:20H2O

[0100] The above mixture was placed in a crystallization kettle with a polytetrafluoroethylene liner and placed in a 165°C oven for crystallization for 264 hours. The solid after the reaction was filtered, washed, dried, and calcined to obtain the final SCM-44 molecular sieve product. The XRD spectrum data is shown in Table 4, and the raw material composition for synthesizing the molecular sieve is shown in Table 6.

[0101] Table 4

[0102]

[0103]

[0104] Example 5

[0105] Dissolve 0.93g of germanium oxide and 0.74g of aluminum sulfate 18hydrate in 25.31g of 1,1,3,5-TMPOH aqueous solution (20wt%), slowly add 1.965g of white carbon black (containing 95wt% SiO2), stir at room temperature, leave the container open and stir overnight to evaporate part of the water, add 3g of hydrofluoric acid (40wt%), stir evenly and adjust the amount of water until the reaction mixture reaches the following molar composition:

[0106] 0.8(1,1,3,5-TMPOH):0.778SiO2:0.222GeO2:0.028Al2O3:1.5HF:18.5H2O

[0107] Finally, 0.056 g of the SCM-44 molecular sieve prepared in Example 1 was added as a seed crystal, and the mixture was placed in a crystallization kettle with a polytetrafluoroethylene liner and placed in a 175°C oven for crystallization for 312 hours. The solid after the reaction was filtered, washed, dried, and calcined to obtain the final SCM-44 molecular sieve product. The XRD spectrum was consistent with Figure 1 Similarly, the composition of the raw materials for synthesizing the molecular sieve is shown in Table 6.

[0108] Example 6

[0109] 0.38g of germanium oxide, 0.204g of aluminum isopropoxide, and 0.088g of pseudo-boehmite (containing 70wt% Al2O3) were dissolved in 38g of 1,1,3,5-TMPOH aqueous solution (20wt%), 4.16g of tetraethyl orthosilicate (TEOS) and 1.033g of white carbon black (containing 95wt% SiO2) were slowly added, and stirred at room temperature. After the hydrolysis was complete, the container was opened and stirred overnight to volatilize ethanol, isopropanol and part of the water, and 2.4g of hydrofluoric acid (40wt%) and 4.8g of ammonium fluoride solution (37wt%) were added. After stirring evenly, the amount of water was adjusted until the reaction mixture reached the following molar composition:

[0110] 1.2(1,1,3,5-TMPOH):0.909SiO2:0.091GeO2:0.028Al2O3:1.2HF:1.2NH4F:15H2O

[0111] The above mixture was placed in a crystallization kettle with a polytetrafluoroethylene liner and placed in a 160°C oven for crystallization for 336 hours. The solid after the reaction was filtered, washed, dried, and calcined to obtain the final SCM-44 molecular sieve product. The XRD spectrum was consistent with Figure 1 Similarly, the composition of the raw materials for synthesizing the molecular sieve is shown in Table 6.

[0112] Example 7

[0113] 0.698g of germanium oxide and 0.408g of aluminum isopropoxide were dissolved in 15.82g of 1,1,3,5-TMPOH aqueous solution (20wt%), 6.761g of tetraethyl orthosilicate (TEOS) and 0.277g of tetrabutyl titanate (TBOT) were slowly added, and the mixture was stirred at room temperature. After the hydrolysis was complete, the container was opened and stirred overnight to evaporate ethanol, isopropanol, butanol and part of the water, and 1g of hydrofluoric acid (40wt%) was added. After stirring evenly, the amount of water was adjusted until the reaction mixture reached the following molar composition:

[0114] 0.5(1,1,3,5-TMPOH):0.8125SiO2:0.167GeO2:0.0208TiO2:0.025Al2O3:0.5HF:16H2O

[0115] The above mixture was placed in a crystallization kettle with a polytetrafluoroethylene liner and placed in a 175°C oven for crystallization for 288 hours. The solid after the reaction was filtered, washed, dried, and calcined to obtain the final SCM-44 molecular sieve product. The XRD spectrum data is shown in Table 5, and the raw material composition for synthesizing the molecular sieve is shown in Table 6.

[0116] Table 5

[0117]

[0118] Example 8

[0119] 0.698g germanium oxide, 0.367g aluminum isopropoxide, and 0.012g boric acid were dissolved in 15.82g 1,1,3,5-TMPOH aqueous solution (20wt%), 6.934g tetraethyl orthosilicate (TEOS) were slowly added, and stirred at room temperature. After the hydrolysis was complete, the container was opened and stirred overnight to evaporate ethanol, isopropanol and part of the water, and 1g hydrofluoric acid (40wt%) was added. After stirring evenly, the amount of water was adjusted until the reaction mixture reached the following molar composition:

[0120] 0.5(1,1,3,5-TMPOH):0.833SiO2:0.167GeO2:0.0225Al2O3:0.0025B2O3:0.5HF:16H2O

[0121] The above mixture was placed in a crystallization kettle with a polytetrafluoroethylene liner and placed in a 175°C oven for crystallization for 300 hours. The solid after the reaction was filtered, washed, dried, and calcined to obtain the final SCM-44 molecular sieve product. The XRD spectrum was consistent with Figure 1 Similarly, the composition of the raw materials for synthesizing the molecular sieve is shown in Table 6.

[0122] Example 9

[0123] Dissolve 0.698g germanium oxide, 0.306g aluminum isopropoxide, and 0.031g boric acid in 15.82g 1,1,3,5-TMPOH aqueous solution (20wt%), slowly add 6.934g tetraethyl orthosilicate (TEOS), stir at room temperature, and after complete hydrolysis, open the container and stir overnight to volatilize ethanol, isopropanol and part of the water, add 1g hydrofluoric acid (40wt%), stir evenly, and adjust the amount of water until the reaction mixture reaches the following molar composition:

[0124] 0.5(1,1,3,5-TMPOH):0.833SiO2:0.167GeO2:0.01875Al2O3:0.00625B2O3:0.5HF:16H2O

[0125] The above mixture was placed in a crystallization kettle with a polytetrafluoroethylene liner and placed in a 175°C oven for crystallization for 312 hours. The solid after the reaction was filtered, washed, dried, and calcined to obtain the final SCM-44 molecular sieve product. The XRD spectrum was consistent with Figure 1 Similarly, the composition of the raw materials for synthesizing the molecular sieve is shown in Table 6.

[0126] Example 10

[0127] 0.698g germanium oxide, 0.367g aluminum isopropoxide, 0.012g boric acid were dissolved in 15.82g 1,1,3,5-TMPOH aqueous solution (20wt%), 6.761g tetraethyl orthosilicate (TEOS) and 0.277g tetrabutyl titanate (TBOT) were slowly added, and stirred at room temperature. After the hydrolysis was complete, the container was opened and stirred overnight to volatilize ethanol, isopropanol, butanol and part of the water, and 1g hydrofluoric acid (40wt%) was added. After stirring evenly, the amount of water was adjusted until the reaction mixture reached the following molar composition:

[0128] 0.5(1,1,3,5-TMPOH):0.8125SiO2:0.167GeO2:0.0208TiO2:0.0225Al2O3:0.0025B2O3:0.5HF:16H2O

[0129] The above mixture was placed in a crystallization kettle with a polytetrafluoroethylene liner and placed in an oven at 180°C for crystallization for 216 hours. The solid after the reaction was filtered, washed, dried and calcined to obtain the final SCM-44 molecular sieve product. The XRD spectrum was consistent with Figure 1 Similarly, the composition of the raw materials for synthesizing the molecular sieve is shown in Table 6.

[0130] Table 6 Composition of raw materials used in the preparation of molecular sieves in each embodiment (molar ratio)

[0131]

[0132]

[0133] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A sheet-like SCM-44 molecular sieve, whose chemical composition is mSiO2·nGeO2·xXO 1.5 ,in, X is a trivalent skeleton element, the molar ratio of SiO2 to GeO2 is m:n=(2-25):1, and the sum of the molar numbers of SiO2 and GeO2 is equal to XO 1.5 The molar ratio (m+n): x=(15-30):

1.

2. The molecular sieve according to claim 1, characterized in that m:n=(2.5-20):1; and / or, (m+n):x=(18-25):1; and / or, m+n=1; and / or, X is selected from at least one of Group IIIA elements, Group VIII elements, Group VIB elements or Group IIIB elements, preferably at least one of aluminum, boron, iron, gallium, indium and chromium, more preferably aluminum and / or boron; Optionally, Si in the SCM-44 molecular sieve is replaced by at least one non-silicon tetravalent framework element Y; preferably, the non-silicon tetravalent framework element Y is selected from at least one of tin, titanium, zirconium and hafnium; preferably, no more than 10wt% of the Si element in the molecular sieve is replaced by the non-silicon tetravalent framework element.

3. The molecular sieve according to claim 1 or 2, characterized in that: The thickness of the SCM-44 molecular sieve is 20 to 500 nm; and / or, The specific surface area of ​​the SCM-44 molecular sieve is greater than 500m 2 / g, and / or, The micropore volume of the SCM-44 molecular sieve is greater than 0.20 cm 3 / g, and / or, The X-ray diffraction spectrum of the SCM-44 molecular sieve includes the following characteristic peaks:

4. The method for preparing the sheet-like SCM-44 molecular sieve according to any one of claims 1 to 3, comprising the following steps: A mixed solution including a silicon source, a germanium source, an optional non-silicon tetravalent framework element Y source, a trivalent framework element X source, a fluorine source, a structure directing agent R and water is subjected to a crystallization reaction to obtain a flaky SCM-44 molecular sieve.

5. The preparation method according to claim 4, characterized in that: The silicon source is calculated as SiO2, the germanium source is calculated as GeO2, the non-silicon tetravalent skeleton element Y source is calculated as oxide YO2, the trivalent skeleton element X source is calculated as oxide X2O3, and the fluorine source is calculated as F. In the mixed solution, the molar ratio of SiO2 to GeO2 is (2-25):1, preferably (2.5-20):1; and / or, The molar ratio of YO2 to SiO2 is (0-0.1):1, preferably (0.01-0.09):1; and / or, The ratio of the sum of the molar numbers of SiO2 and GeO2 to the molar number of X2O3 is (30-60):1, preferably (36-50):1; and / or, The molar ratio of the sum of the moles of SiO2 and GeO2 to F is 1:(0.2-4), preferably 1:(0.35-2.5):1; and / or, The molar ratio of the sum of the moles of SiO2 and GeO2 to the structure directing agent R is 1:(0.15-4), preferably 1:(0.35-2); Preferably, in the mixed solution, the molar ratio of structure directing agent R, SiO2, GeO2, X2O3, F and water is (0.15-4):(0.667-0.962):(0.038-0.333):(0.0167-0.0333):(0.2-4):(8-35).

6. The preparation method according to claim 4 or 5, characterized in that: The silicon source is selected from at least one of water glass, silica sol, solid silica gel, fumed silica, amorphous silica, diatomaceous earth, zeolite molecular sieve and tetraalkoxysilane; and / or, The germanium source is selected from at least one of germanium oxide, germanium nitrate and tetraalkoxygermanium; and / or, The non-silicon tetravalent skeleton element Y source is selected from at least one of a tin source, a titanium source, a zirconium source and a hafnium source; preferably, the tin source is selected from at least one of tin tetrachloride, stannous chloride, alkyl tin, alkoxy tin and organic tin esters, the titanium source is selected from at least one of tetraalkyl titanates such as tetramethyl titanate, tetraethyl titanate, tetrapropyl titanate, tetra-n-butyl titanate, titanium tetrachloride, hexafluorotitanic acid, titanium sulfate and their hydrolyzates, the zirconium source is selected from at least one of zirconium nitrate, zirconium tetrachloride, zirconium oxide and alkoxy zirconium; the hafnium source is selected from at least one of hafnium oxide and hafnium sulfate; and / or, The trivalent skeleton element X source is selected from at least one of an aluminum source, a boron source, an iron source, a gallium source, an indium source and a chromium source. Preferably, the aluminum source is selected from at least one of aluminum sulfate, sodium aluminate, aluminum nitrate, aluminum chloride, pseudo-boehmite, aluminum oxide, aluminum hydroxide, silica-aluminum zeolite molecular sieve, aluminum carbonate, elemental aluminum, aluminum isopropoxide and aluminum acetate; the boron source is selected from at least one of boric acid, sodium tetraborate, amorphous boron oxide, potassium borate, sodium metaborate, ammonium tetraborate and organic boron esters; the iron source is selected from at least one of ferric sulfate, ferric nitrate, iron halide such as ferric chloride, ferrocene and ferric citrate; the gallium source is selected from at least one of gallium oxide and gallium nitrate; the indium source is selected from at least one of indium oxide and indium nitrate; the chromium source is selected from at least one of chromium oxide, chromium chloride and chromium nitrate; and / or, The fluorine source is selected from at least one of hydrofluoric acid, ammonium fluoride, sodium fluoride and potassium fluoride.

7. The preparation method according to any one of claims 4 to 6, wherein the structure directing agent R is selected from a compound containing a 1,1,3,5-tetraalkylpiperidinium ion or a structure shown in Formula I, In Formula I, R1 to R4 are each independently selected from H and C 1-6 alkyl, preferably hydrogen, methyl, ethyl, propyl, isopropyl, butyl, isobutyl and tert-butyl; Preferably, the anion X in the structure directing agent - Selected from halogen ions and hydroxide ions, preferably Cl - Br - ,I - and OH-, more preferably OH-; Preferably, the structure directing agent R is 1,1,3,5-tetramethylpiperidinium hydroxide.

8. The preparation method according to any one of claims 4 to 7, characterized in that: The temperature of the crystallization reaction is 100-200°C, preferably 155-175°C; And / or, the crystallization reaction time is 72-600 hours, preferably 120-360 hours; And / or, the method further comprises: performing post-treatment after the crystallization reaction, wherein the post-treatment comprises the steps of filtering, washing, drying and optional calcination.

9. A molecular sieve composition, comprising the SCM-44 molecular sieve according to any one of claims 1 to 3, and a binder; Preferably, the binder is selected from at least one of clay, clay, silica gel, alumina, silicon oxide and magnesium oxide.

10. Use of the SCM-44 molecular sieve according to any one of claims 1 to 3 or the molecular sieve composition according to claim 9 in catalytic reaction, adsorption or ion exchange.

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