Preparation method of scm-52 molecular sieve precursor, scm-52 molecular sieve precursor and application thereof

Abstract

The application relates to a preparation method of an SCM-52 molecular sieve precursor, the SCM-52 molecular sieve precursor and application thereof. The SCM-52 molecular sieve precursor provided by the application comprises silicon dioxide, di-aluminum trioxide, an organic structure directing agent and a silylating agent, wherein the organic structure directing agent comprises a compound shown in formula I (each group is defined in the description). The SCM-52 molecular sieve precursor has a new skeleton structure and / or chemical composition, and has very important application value.

Description

Technical Field

[0001] This invention relates to the field of molecular sieves, specifically to a method for preparing an SCM-52 molecular sieve precursor, the SCM-52 molecular sieve precursor, and its applications. Background Technology

[0002] Molecular sieves are crystalline aluminosilicates with a uniform porous structure. Their spatial network structure consists of alternating silicon-oxygen tetrahedral units [SiO4] and aluminum-oxygen tetrahedral units [AlO4]. The molecular sieve structure contains a large amount of water of crystallization. During heating, the loss of this water creates numerous cavities of varying sizes, interconnected by micropores of the same diameter, forming uniform channels with a diameter equivalent to that of a molecule. This allows them to repel molecules larger than the pore size, thus achieving the function of sieving molecules, hence the name "molecular sieve." This structural characteristic endows molecular sieves with three main properties: selective adsorption, catalysis, and ion exchange. Therefore, they are widely used in industries such as petroleum, chemicals, and metallurgy.

[0003] The specific structure of molecular sieve materials is determined by X-ray diffraction (XRD). The position, relative intensity, and width of peaks in an XRD pattern are related to the chemical composition, grain size, and shape of the material. XRD patterns of different samples may vary slightly due to variations in unit cell parameters. Different zeolite molecular sieves exhibit different XRD pattern characteristics. Furthermore, molecular sieves with the same topology generally have the same XRD pattern characteristics, but different framework elements indicate different molecular sieves. For example, ZSM-5 and TS-1, zeolite molecular sieves with the same CHA topology, have the same XRD spectroscopic properties but different framework elements; they are two different molecular sieve materials. ZSM-5 molecular sieve material has a framework composed of Si and Al and is mainly used in acid catalysis, while TS-1 molecular sieve material has a framework composed of Si and Ti and is mainly used in catalytic oxidation processes.

[0004] Since different pore structures and elemental compositions determine the unique physicochemical and catalytic properties of molecular sieves, the development of molecular sieves with special structures is particularly important. Summary of the Invention

[0005] This invention provides a novel molecular sieve precursor, SCM-52, which is a germanium-free, high-silicon molecular sieve precursor material with significant application value.

[0006] In a first aspect, the SCM-52 molecular sieve precursor provided by the present invention comprises silica, alumina, an organic structure directing agent OSDA, and a silanizing agent SIL, wherein the organic structure directing agent comprises a compound represented by Formula I.

[0007]

[0008] In Equation I, R1, R2, R3, and R4 may be the same or different, and each is independently selected from C. 1-8 Alkyl, X - Selected from OH - Halogen anions, nitrate ions, or monovalent organic acid anions; R5 and R6 may be the same or different, and each is independently selected from hydrogen, halogens, and carbon. 1-4 alkyl.

[0009] In some implementations, in Formula I, R1, R2, R3, and R4 may be the same or different, and each is independently selected from C. 1-4 Alkyl groups, such as methyl, ethyl, or propyl. In some embodiments, R1 and R3 are the same, and R2 and R4 are the same in Formula I.

[0010] In some implementations, X - Selected from OH - Bromine ions, chloride ions, iodide ions, nitrate ions, or acetate ions.

[0011] In some embodiments, R5 and R6 may be the same or different, and each is independently selected from hydrogen, fluorine, chlorine, bromine, methyl, ethyl or propyl.

[0012] In some embodiments, at least one of R5 and R6 is hydrogen. In some embodiments, both R5 and R6 are hydrogen.

[0013] In some embodiments, the organic structure directing agent is selected from one or more of 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide, 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium bromide, and 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium chloride.

[0014] In some embodiments, the silanizing agent comprises a compound represented by Formula II.

[0015]

[0016] In Equation II, R7, R8, R9 and R 10 Whether the elements are the same or different, they are each independently selected from hydrogen, halogens, and carbon. 1-6 Alkyl, C 1-6 Alkyl group.

[0017] In some implementations, R7, R8, R9 and R 10They may be the same or different, each independently selected from hydrogen, fluorine, chlorine, bromine, methyl, ethyl, propyl, methoxy, ethoxy, and propoxy.

[0018] In some implementations, R7, R8, R9 and R 10 They are the same, both selected from C. 1-4 Alkyl group.

[0019] In some embodiments, the silanizing agent is selected from one or more of tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, monomethylchlorosilane, dimethylchlorosilane, monomethylmethoxysilane, dimethylmethoxysilane, monomethylethoxysilane, and dimethylethoxysilane.

[0020] In some embodiments, the molar ratio (i.e., silicon-to-alumina ratio) of silicon dioxide to aluminum oxide in the SCM-52 molecular sieve precursor is 10-500, for example, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 1 80, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 410, 420, 430, 440, 450, 460, 470, 480, 490, or any value between them. In some embodiments, the molar ratio of silicon dioxide to aluminum oxide is 20-200.

[0021] In some embodiments, the molar ratio of silica to the organic structure-directing agent OSDA in the SCM-52 molecular sieve precursor is 5-40. In some embodiments, the molar ratio of silica to the organic structure-directing agent in the SCM-52 molecular sieve precursor is 5, 6, 7, 8, 9, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20, 20.5, 21, 21.5, 22. The values ​​are 22.5, 23, 23.5, 24, 24.5, 25, 25.5, 26, 26.5, 27, 27.5, 28, 28.5, 29, 29.5, 30, 30.5, 31, 31.5, 32, 32.5, 33, 33.5, 34, 34.5, 35, 35.5, 36, 36.5, 37, 37.5, 38, 38.5, 39, 39.5, or any value between them. In some embodiments, the molar ratio of silica to the organic structure-directing agent OSDA is 20-40.

[0022] In some embodiments, the molar ratio of silica to silanizing agent in the SCM-52 molecular sieve precursor is 200-800. In some embodiments, the molar ratio of silica to silanizing agent in the SCM-52 molecular sieve precursor is 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 410, or 42. 0, 430, 440, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570, 580, 590, 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, 700, 710, 720, 730, 740, 750, 760, 770, 780, 790, or any value between them. In some embodiments, the molar ratio of silica to the silanizing agent SIL is 300-600.

[0023] In some embodiments, the SCM-52 molecular sieve precursor has a chemical composition with the following molar ratio: mSiO2·nAl2O3·qOSDA·ySIL, wherein 10≤m / n≤500, 5≤m / q≤40, and 200≤m / y≤800.

[0024] In some implementations, m / n is 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205. 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 410, 420, 430, 440, 450, 460, 470, 480, 490, or any value between them. In some implementations, 20 ≤ m / n ≤ 200.

[0025] In some implementations, m / q is 5, 6, 7, 8, 9, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20, 20.5, 21, 21.5, 22, 22.5, 23, 23.5, 2 4, 24.5, 25, 25.5, 26, 26.5, 27, 27.5, 28, 28.5, 29, 29.5, 30, 30.5, 31, 31.5, 32, 32.5, 33, 33.5, 34, 34.5, 35, 35.5, 36, 36.5, 37, 37.5, 38, 38.5, 39, 39.5, or any value between them. In some implementations, 20 ≤ m / q ≤ 40.

[0026] In some implementations, m / y is 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 410, 420, 430, 440, 450. 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570, 580, 590, 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, 700, 710, 720, 730, 740, 750, 760, 770, 780, 790, or any value between them. In some implementations, 300 ≤ m / y ≤ 600.

[0027] In some embodiments, in the illustrative chemical composition shown by the formula “mSiO2·nAl2O3·qOSDA”, the molar ratio of water to the silicon source is 8-100, preferably 15-100, and more preferably 15-50.

[0028] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes one or more diffraction peaks with 2θ of 3.985°±0.30°, 8.306°±0.30°, 12.081°±0.30°, and 25.921°±0.50°.

[0029] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes diffraction peaks with 2θ values ​​of 3.985°±0.03°, 3.985°±0.05°, 3.985°±0.07°, 3.985°±0.1°, 3.985°±0.13°, 3.985°±0.15°, 3.985°±0.17°, 3.985°±0.2°, 3.985°±0.23°, 3.985°±0.25°, or 3.985°±0.27°.

[0030] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes diffraction peaks with 2θ values ​​of 8.306°±0.03°, 8.306°±0.05°, 8.306°±0.07°, 8.306°±0.1°, 8.306°±0.13°, 8.306°±0.15°, 8.306°±0.17°, 8.306°±0.2°, 8.306°±0.23°, 8.306°±0.25°, or 8.306°±0.27°.

[0031] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes diffraction peaks with 2θ values ​​of 12.081°±0.03°, 12.081°±0.05°, 12.081°±0.07°, 12.081°±0.1°, 12.081°±0.13°, 12.081°±0.15°, 12.081°±0.17°, 12.081°±0.2°, 12.081°±0.23°, 12.081°±0.25°, or 12.081°±0.27°.

[0032] In some embodiments, the X-ray diffraction patterns of the SCM-52 molecular sieve precursor include 2θ values ​​of 25.921°±0.03°, 25.921°±0.05°, 25.921°±0.07°, 25.921°±0.1°, 25.921°±0.13°, 25.921°±0.15°, 25.921°±0.17°, 25.921°±0.2°, and 25.92°±0.2°. Diffraction peaks at 1°±0.23°, 25.921°±0.25°, 25.921°±0.27°, 25.921°±0.3°, 25.921°±0.33°, 25.921°±0.35°, 25.921°±0.37°, 25.921°±0.4°, 25.921°±0.43°, 25.921°±0.45°, or 25.921°±0.47°.

[0033] In some embodiments, the strongest diffraction peak in the X-ray diffraction pattern of the SCM-52 molecular sieve precursor is the one with 2θ of 3.985°±0.30°.

[0034] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor further includes one or more diffraction peaks with 2θ values ​​of 13.941°±0.30°, 17.88°±0.50°, 22.146°±0.50°, and 24.225°±0.30°.

[0035] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor also includes diffraction peaks with 2θ values ​​of 13.941°±0.03°, 13.941°±0.05°, 13.941°±0.07°, 13.941°±0.1°, 13.941°±0.13°, 13.941°±0.15°, 13.941°±0.17°, 13.941°±0.2°, 13.941°±0.23°, 13.941°±0.25°, or 13.941°±0.27°.

[0036] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor further includes 2θ values ​​of 17.88°±0.03°, 17.88°±0.05°, 17.88°±0.07°, 17.88°±0.1°, 17.88°±0.13°, 17.88°±0.15°, 17.88°±0.17°, 17.88°±0.2°, and 17... Diffraction peaks at 0.88°±0.23°, 17.88°±0.25°, 17.88°±0.27°, 17.88°±0.3°, 17.88°±0.33°, 17.88°±0.35°, 17.88°±0.37°, 17.88°±0.4°, 17.88°±0.43°, 17.88°±0.45°, or 17.88°±0.47°.

[0037] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor further includes 2θ values ​​of 22.146°±0.03°, 22.146°±0.05°, 22.146°±0.07°, 22.146°±0.1°, 22.146°±0.13°, 22.146°±0.15°, 22.146°±0.17°, 22.146°±0.2°, and 22.1°±0.17°. Diffraction peaks at 46°±0.23°, 22.146°±0.25°, 22.146°±0.27°, 22.146°±0.3°, 22.146°±0.33°, 22.146°±0.35°, 22.146°±0.37°, 22.146°±0.4°, 22.146°±0.43°, 22.146°±0.45°, or 22.146°±0.47°.

[0038] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor also includes diffraction peaks with 2θ values ​​of 24.225°±0.03°, 24.225°±0.05°, 24.225°±0.07°, 24.225°±0.1°, 24.225°±0.13°, 24.225°±0.15°, 24.225°±0.17°, 24.225°±0.2°, 24.225°±0.23°, 24.225°±0.25°, or 24.225°±0.27°.

[0039] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table A:

[0040] Table A

[0041] 3.985°±0.30° vs 8.306°±0.30° ms 12.081°±0.30° ms 25.921°±0.50° s-vs .

[0042] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table A-1:

[0043] Table A-1

[0044]

[0045]

[0046] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table B:

[0047] Table B

[0048] 3.985°±0.30° vs 8.306°±0.30° ms 12.081°±0.30° ms 13.941°±0.30° wm 17.88°±0.50° wm 22.146°±0.50° wm 24.225°±0.30° wm 25.921°±0.50° s-vs .

[0049] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table B-1:

[0050] Table B-1

[0051] 3.985°±0.30° 100 8.306°±0.30° 20-45 12.081°±0.30° 20-40 13.941°±0.30° 10-30 17.88°±0.50° 10-25 22.146°±0.50° 10-25 24.225°±0.30° 10-30 25.921°±0.50° 50-70 .

[0052] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table C:

[0053] Table C

[0054]

[0055] Where b: varies with 2θ.

[0056] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table C-1:

[0057] Table C-1

[0058]

[0059] Where b: varies with 2θ.

[0060] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table D:

[0061] Table D

[0062]

[0063] Where b: varies with 2θ.

[0064] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table D-1:

[0065] Table D-1

[0066]

[0067] Where b: varies with 2θ.

[0068] In some embodiments, the SCM-52 molecular sieve precursor crystals have a nanosheet morphology. In some embodiments, the average thickness of the crystals is less than or equal to 30 nm.

[0069] In some embodiments, the average thickness of the crystal is 2nm-27nm, for example, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, 10nm, 11nm, 12nm, 13nm, 14nm, 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, 21nm, 22nm, 23nm, 24nm, 25nm, 26nm, or any value between them. In some embodiments, the average thickness of the crystal is 5nm-25nm.

[0070] In some embodiments, the SCM-52 molecular sieve precursor comprises silicon, aluminum, oxygen, and nitrogen.

[0071] In some embodiments, the SCM-52 molecular sieve precursor further includes non-silicon and non-aluminum elements, preferably selected from one or more of sodium, potassium, germanium, titanium, boron, zirconium, tin and iron.

[0072] In some embodiments, the SCM-52 molecular sieve precursor further includes one or more elements selected from sodium, potassium, germanium, titanium, boron, zirconium, tin, and iron.

[0073] Secondly, the present invention provides an X-ray diffraction pattern of the SCM-52 molecular sieve precursor including one or more diffraction peaks with 2θ of 3.985°±0.30°, 8.306°±0.30°, 12.081°±0.30° and 25.921°±0.50°.

[0074] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes diffraction peaks with 2θ values ​​of 3.985°±0.03°, 3.985°±0.05°, 3.985°±0.07°, 3.985°±0.1°, 3.985°±0.13°, 3.985°±0.15°, 3.985°±0.17°, 3.985°±0.2°, 3.985°±0.23°, 3.985°±0.25°, or 3.985°±0.27°.

[0075] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes diffraction peaks with 2θ values ​​of 8.306°±0.03°, 8.306°±0.05°, 8.306°±0.07°, 8.306°±0.1°, 8.306°±0.13°, 8.306°±0.15°, 8.306°±0.17°, 8.306°±0.2°, 8.306°±0.23°, 8.306°±0.25°, or 8.306°±0.27°.

[0076] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes diffraction peaks with 2θ values ​​of 12.081°±0.03°, 12.081°±0.05°, 12.081°±0.07°, 12.081°±0.1°, 12.081°±0.13°, 12.081°±0.15°, 12.081°±0.17°, 12.081°±0.2°, 12.081°±0.23°, 12.081°±0.25°, or 12.081°±0.27°.

[0077] In some embodiments, the X-ray diffraction patterns of the SCM-52 molecular sieve precursor include 2θ values ​​of 25.921°±0.03°, 25.921°±0.05°, 25.921°±0.07°, 25.921°±0.1°, 25.921°±0.13°, 25.921°±0.15°, 25.921°±0.17°, 25.921°±0.2°, and 25.92°±0.2°. Diffraction peaks at 1°±0.23°, 25.921°±0.25°, 25.921°±0.27°, 25.921°±0.3°, 25.921°±0.33°, 25.921°±0.35°, 25.921°±0.37°, 25.921°±0.4°, 25.921°±0.43°, 25.921°±0.45°, or 25.921°±0.47°.

[0078] In some embodiments, the strongest diffraction peak in the X-ray diffraction pattern of the SCM-52 molecular sieve precursor is the one with 2θ of 3.985°±0.30°.

[0079] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor further includes one or more diffraction peaks with 2θ values ​​of 13.941°±0.30°, 17.88°±0.50°, 22.146°±0.50°, and 24.225°±0.30°.

[0080] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor also includes diffraction peaks with 2θ values ​​of 13.941°±0.03°, 13.941°±0.05°, 13.941°±0.07°, 13.941°±0.1°, 13.941°±0.13°, 13.941°±0.15°, 13.941°±0.17°, 13.941°±0.2°, 13.941°±0.23°, 13.941°±0.25°, or 13.941°±0.27°.

[0081] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor further includes 2θ values ​​of 17.88°±0.03°, 17.88°±0.05°, 17.88°±0.07°, 17.88°±0.1°, 17.88°±0.13°, 17.88°±0.15°, 17.88°±0.17°, 17.88°±0.2°, and 17... Diffraction peaks at 0.88°±0.23°, 17.88°±0.25°, 17.88°±0.27°, 17.88°±0.3°, 17.88°±0.33°, 17.88°±0.35°, 17.88°±0.37°, 17.88°±0.4°, 17.88°±0.43°, 17.88°±0.45°, or 17.88°±0.47°.

[0082] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor further includes 2θ values ​​of 22.146°±0.03°, 22.146°±0.05°, 22.146°±0.07°, 22.146°±0.1°, 22.146°±0.13°, 22.146°±0.15°, 22.146°±0.17°, 22.146°±0.2°, and 22.1°±0.17°. Diffraction peaks at 46°±0.23°, 22.146°±0.25°, 22.146°±0.27°, 22.146°±0.3°, 22.146°±0.33°, 22.146°±0.35°, 22.146°±0.37°, 22.146°±0.4°, 22.146°±0.43°, 22.146°±0.45°, or 22.146°±0.47°.

[0083] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor also includes diffraction peaks with 2θ values ​​of 24.225°±0.03°, 24.225°±0.05°, 24.225°±0.07°, 24.225°±0.1°, 24.225°±0.13°, 24.225°±0.15°, 24.225°±0.17°, 24.225°±0.2°, 24.225°±0.23°, 24.225°±0.25°, or 24.225°±0.27°.

[0084] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table A:

[0085] Table A

[0086] 3.985°±0.30° vs 8.306°±0.30° ms 12.081°±0.30° ms 25.921°±0.50° s-vs .

[0087] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table A-1:

[0088] Table A-1

[0089] 3.985°±0.30° 100 8.306°±0.30° 20-45 12.081°±0.30° 20-40 25.921°±0.50° 50-70 .

[0090] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table B:

[0091] Table B

[0092]

[0093]

[0094] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table B-1:

[0095] Table B-1

[0096] 3.985°±0.30° 100 8.306°±0.30° 20-45 12.081°±0.30° 20-40 13.941°±0.30° 10-30 17.88°±0.50° 10-25 22.146°±0.50° 10-25 24.225°±0.30° 10-30 25.921°±0.50° 50-70 .

[0097] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table C:

[0098] Table C

[0099]

[0100] Where b: varies with 2θ.

[0101] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table C-1:

[0102] Table C-1

[0103]

[0104] Where b: varies with 2θ.

[0105] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table D:

[0106] Table D

[0107]

[0108]

[0109] Where b: varies with 2θ.

[0110] In some embodiments, the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table D-1:

[0111] Table D-1

[0112]

[0113] Where b: varies with 2θ.

[0114] In some embodiments, the SCM-52 molecular sieve precursor comprises silicon, aluminum, oxygen, and nitrogen.

[0115] In some embodiments, the SCM-52 molecular sieve precursor comprises silica, alumina, an organic structure directing agent, and a silanizing agent, wherein the organic structure directing agent comprises a compound represented by Formula I.

[0116]

[0117] In Equation I, R1, R2, R3, and R4 may be the same or different, and each is independently selected from C. 1-8 Alkyl, X - Selected from OH - Halogen anions, nitrate ions, or monovalent organic acid anions; R5 and R6 may be the same or different, and each is independently selected from hydrogen, halogens, and carbon. 1-4 alkyl.

[0118] In some implementations, in Formula I, R1, R2, R3, and R4 may be the same or different, and each is independently selected from C. 1-4 Alkyl groups, such as methyl, ethyl, or propyl. In some embodiments, R1 and R3 are the same, and R2 and R4 are the same in Formula I.

[0119] In some implementations, X - Selected from OH - Bromine ions, chloride ions, iodide ions, nitrate ions, or acetate ions.

[0120] In some embodiments, R5 and R6 may be the same or different, and each is independently selected from hydrogen, fluorine, chlorine, bromine, methyl, ethyl or propyl.

[0121] In some embodiments, at least one of R5 and R6 is hydrogen. In some embodiments, both R5 and R6 are hydrogen.

[0122] In some embodiments, the organic structure directing agent is selected from one or more of 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide, 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium bromide, and 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium chloride.

[0123] In some embodiments, the silanizing agent comprises a compound represented by Formula II.

[0124]

[0125] In Equation II, R7, R8, R9 and R 10 Whether the elements are the same or different, they are each independently selected from hydrogen, halogens, and carbon. 1-6 Alkyl, C 1-6 Alkyl group.

[0126] In some implementations, R7, R8, R9 and R 10 They may be the same or different, each independently selected from hydrogen, fluorine, chlorine, bromine, methyl, ethyl, propyl, methoxy, ethoxy, and propoxy.

[0127] In some implementations, R7, R8, R9 and R 10 They are the same, both selected from C. 1-4 Alkyl group.

[0128] In some embodiments, the silanizing agent is selected from one or more of tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, monomethylchlorosilane, dimethylchlorosilane, monomethylmethoxysilane, dimethylmethoxysilane, monomethylethoxysilane, and dimethylethoxysilane.

[0129] In some embodiments, the molar ratio (i.e., silicon-to-alumina ratio) of silicon dioxide to aluminum oxide in the SCM-52 molecular sieve precursor is 10-500, for example, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 1 80, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 410, 420, 430, 440, 450, 460, 470, 480, 490, or any value between them. In some embodiments, the molar ratio of silicon dioxide to aluminum oxide is 20-200.

[0130] In some embodiments, the molar ratio of silica to the organic structure-directing agent OSDA in the SCM-52 molecular sieve precursor is 5-40. In some embodiments, the molar ratio of silica to the organic structure-directing agent in the SCM-52 molecular sieve precursor is 5, 6, 7, 8, 9, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20, 20.5, 21, 21.5, 22. The values ​​are 22.5, 23, 23.5, 24, 24.5, 25, 25.5, 26, 26.5, 27, 27.5, 28, 28.5, 29, 29.5, 30, 30.5, 31, 31.5, 32, 32.5, 33, 33.5, 34, 34.5, 35, 35.5, 36, 36.5, 37, 37.5, 38, 38.5, 39, 39.5, or any value between them. In some embodiments, the molar ratio of silica to the organic structure-directing agent OSDA is 20-40.

[0131] In some embodiments, the molar ratio of silica to silanizing agent in the SCM-52 molecular sieve precursor is 200-800. In some embodiments, the molar ratio of silica to silanizing agent SIL in the SCM-52 molecular sieve precursor is 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 410, 4... 20, 430, 440, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570, 580, 590, 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, 700, 710, 720, 730, 740, 750, 760, 770, 780, 790, or any value between them. In some embodiments, the molar ratio of silica to the silanizing agent SIL is 300-600.

[0132] In some embodiments, the SCM-52 molecular sieve precursor has a chemical composition with the following molar ratio: mSiO2·nAl2O3·qOSDA·ySIL, where OSDA represents an organic structure directing agent, SIL represents a silanizing agent, 10≤m / n≤500, 5≤m / q≤40, and 200≤m / y≤800.

[0133] In some implementations, m / n is 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205. 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 410, 420, 430, 440, 450, 460, 470, 480, 490, or any value between them. In some implementations, 20 ≤ m / n ≤ 200.

[0134] In some implementations, m / q is 5, 6, 7, 8, 9, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20, 20.5, 21, 21.5, 22, 22.5, 23, 23.5, 2 4, 24.5, 25, 25.5, 26, 26.5, 27, 27.5, 28, 28.5, 29, 29.5, 30, 30.5, 31, 31.5, 32, 32.5, 33, 33.5, 34, 34.5, 35, 35.5, 36, 36.5, 37, 37.5, 38, 38.5, 39, 39.5, or any value between them. In some implementations, 20 ≤ m / q ≤ 40.

[0135] In some implementations, m / y is 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 410, 420, 430, 440, 450. 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570, 580, 590, 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, 700, 710, 720, 730, 740, 750, 760, 770, 780, 790, or any value between them. In some implementations, 300 ≤ m / y ≤ 600.

[0136] In some embodiments, in the illustrative chemical composition shown by the formula “mSiO2·nAl2O3·qOSDA”, the molar ratio of water to the silicon source is 8-100, preferably 15-100, and more preferably 15-50.

[0137] In this invention, OSDA represents Organic Structure-Directing Agent, and SIL represents silylation.

[0138] In some embodiments, the SCM-52 molecular sieve precursor crystals have a nanosheet morphology. In some embodiments, the average thickness of the crystals is less than or equal to 30 nm.

[0139] In some embodiments, the average thickness of the crystal is 2nm-27nm, for example, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, 10nm, 11nm, 12nm, 13nm, 14nm, 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, 21nm, 22nm, 23nm, 24nm, 25nm, 26nm, or any value between them. In some embodiments, the average thickness of the crystal is 5nm-25nm.

[0140] In some embodiments, the SCM-52 molecular sieve precursor further includes non-silicon and non-aluminum elements, preferably selected from one or more of sodium, potassium, germanium, titanium, boron, zirconium, tin and iron.

[0141] In some embodiments, the SCM-52 molecular sieve precursor further includes one or more elements selected from sodium, potassium, germanium, titanium, boron, zirconium, tin, and iron.

[0142] Thirdly, the present invention provides a method for preparing an SCM-52 molecular sieve precursor, which includes the following steps:

[0143] S1: A mixture containing a silicon source, an aluminum source, an organic structure directing agent, and a solvent is subjected to crystallization treatment to obtain a crystallized product;

[0144] S2: Under acidic conditions, the crystallized product is mixed with a silanizing agent and then subjected to hydrothermal treatment; preferably, the organic structure directing agent comprises a compound represented by Formula I.

[0145]

[0146] In Equation I, R1, R2, R3, and R4 may be the same or different, and each is independently selected from C. 1-8 Alkyl, X -Selected from OH - Halogen anions, nitrates, or monovalent organic acid anions; R5 and R6 may be the same or different, and are independently selected from hydrogen, halogens, and carbon. 1-4 alkyl.

[0147] In some implementations, in Formula I, R1, R2, R3, and R4 may be the same or different, and each is independently selected from C. 1-4 Alkyl groups, such as methyl, ethyl, or propyl. In some embodiments, R1 and R3 are the same, and R2 and R4 are the same in Formula I.

[0148] In some implementations, X - Selected from OH - Bromine ions, chloride ions, iodide ions, nitrate ions, or acetate ions.

[0149] In some embodiments, R5 and R6 may be the same or different, and each is independently selected from hydrogen, fluorine, chlorine, bromine, methyl, ethyl or propyl.

[0150] In some embodiments, at least one of R5 and R6 is hydrogen. In some embodiments, both R5 and R6 are hydrogen.

[0151] In some embodiments, the organic structure directing agent is selected from one or more of 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide, 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium bromide, and 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium chloride.

[0152] In some embodiments, the silicon source is SiO2 and the aluminum source is Al2O3, and the molar ratio of the silicon source to the aluminum source is 1:(0.0025-0.25), for example 1:0.003, 1:0.0035, 1:0.004, 1:0.0045, 1:0.005, 1:0.0055, 1:0.006, or 1:0.006. 5, 1:0.007, 1:0.0075, 1:0.008, 1:0.0085, 1:0.009, 1:0.0095, 1:0.01, 1:0.015, 1:0.02, 1:0.025, 1:0.03, 1:0.035, 1:0.04, 1:0.045, 1:0.05, 1:0.055, 1: 0.06, 1:0.065, 1:0.07, 1:0.075, 1:0.08, 1:0.085, 1:0.09, 1:0.095, 1:0.1, 1:0.105, 1:0.12, 1:0.125, 1:0.13, 1:0.135, 1:0.14, 1:0.145, 1:0.15, 1:0.15 5, 1:0.16, 1:0.165, 1:0.17, 1:0.175, 1:0.18, 1:0.185, 1:0.19, 1:0.195, 1:0.1, 1:0.205, 1:0.22, 1:0.225, 1:0.23, 1:0.235, 1:0.24, 1:0.245, or any value between them.

[0153] In some embodiments, the molar ratio of the silicon source to the aluminum source is 1:(0.025-0.2). In some embodiments, the molar ratio of the silicon source to the aluminum source is 1:(0.0025-0.15).

[0154] In some embodiments, the silicon source is SiO2, and the molar ratio of the silicon source to the organic structure directing agent is 1:(0.050-0.50), for example, 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09, 1:0.1, 1:0.11, 1:0.12, 1:0.13, 1:0.14, 1:0.15, 1:0.17, 1:0.20, 1:0.23, 1:0.25, 1:0.27, 1:0.30, 1:0.33, 1:0.35, 1:0.37, 1:0.40, 1:0.43, 1:0.45, 1:0.47 or any value between them.

[0155] In some embodiments, the molar ratio of the silicon source to the organic structure directing agent is 1:(0.1-0.50). In some embodiments, the molar ratio of the silicon source to the organic structure directing agent is 1:(0.30-0.50).

[0156] In some embodiments, the silicon source is SiO2, and the molar ratio of the silicon source to the solvent is 1:(8-100), for example, 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, 1:55, 1:60, 1:65, 1:70, 1:75, 1:80, 1:85, 1:90, 1:95, or any value between them.

[0157] In some embodiments, the molar ratio of the silicon source to the solvent is 1:(15-100). In some embodiments, the molar ratio of the silicon source to the solvent is 1:(15-50).

[0158] In some embodiments, the acidic conditions are provided by an acid solution. In some embodiments, the concentration of the acid solution is 0.5 mol / L to 6 mol / L, for example, 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, 3 mol / L, 3.5 mol / L, 4 mol / L, 4.5 mol / L, 5 mol / L, 5.5 mol / L, or any value between them. In some embodiments, the concentration of the acid solution is 1 mol / L to 5 mol / L. In some embodiments, the concentration of the acid solution is 1.5 mol / L to 4.5 mol / L.

[0159] In some embodiments, the liquid-to-solid ratio of the acid solution to the crystallized product is (10-100) mL:1g, for example, 20 mL:1g, 30 mL:1g, 40 mL:1g, 50 mL:1g, 60 mL:1g, 70 mL:1g, 80 mL:1g, or 90 mL:1g. In some embodiments, the liquid-to-solid ratio of the acid solution to the crystallized product is (20-80) mL:1g. In some embodiments, the liquid-to-solid ratio of the acid solution to the crystallized product is (40-60) mL:1g.

[0160] In some embodiments, the mass ratio of the silanizing agent to the crystallized product is (0.1-4):1, for example, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1.0:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2.0:1, 2.3:1, 2.5:1, 2.7:1, 3.0:1, 3.3:1, 3.5:1, or 3.7:1. In some embodiments, the mass ratio of the silanizing agent to the crystallized product is (0.2-2):1. In some embodiments, the mass ratio of the silanizing agent to the crystallized product is (0.2-2.5):1.

[0161] In some embodiments, the acid solution is selected from aqueous hydrochloric acid solution, aqueous acetic acid solution, aqueous nitric acid solution, hydrochloric acid ethanol solution, acetic acid ethanol solution, or nitric acid ethanol solution.

[0162] In some embodiments, the silanizing agent comprises a compound represented by Formula II.

[0163]

[0164] In Equation II, R7, R8, R9 and R 10 Whether the elements are the same or different, they are each independently selected from hydrogen, halogens, and carbon. 1-6 Alkyl, C 1-6 Alkyl group.

[0165] In some implementations, R7, R8, R9 and R 10 They may be the same or different, each independently selected from hydrogen, fluorine, chlorine, bromine, methyl, ethyl, propyl, methoxy, ethoxy, and propoxy.

[0166] In some implementations, R7, R8, R9 and R 10 They are the same, both selected from C. 1-4 Alkyl group.

[0167] In some embodiments, the silanizing agent is selected from one or more of tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, monomethylchlorosilane, dimethylchlorosilane, monomethylmethoxysilane, dimethylmethoxysilane, monomethylethoxysilane, and dimethylethoxysilane.

[0168] In this invention, silanizing agents are used to directionally modify the pore walls of molecular sieve precursors under acidic conditions.

[0169] In some embodiments, the silicon source is selected from one or more of silica sol, silica gel, tetraethyl orthosilicate, silica fume, and silicic acid.

[0170] In some embodiments, the aluminum source is selected from one or more of aluminum hydroxide, aluminum isopropoxide, aluminum nitrate, and aluminum oxide.

[0171] In some embodiments, the solvent is selected from water.

[0172] In some embodiments, the mixture does not contain alkali metals or alkaline earth metals.

[0173] According to one embodiment of the present invention, in the method for synthesizing the molecular sieve precursor, from the perspective of more advantageously obtaining the SCM-52 molecular sieve precursor of the present invention, the mixture does not contain an alkaline source. Examples of alkaline sources include, for example, alkaline substances other than silicon sources, aluminum sources, and organic structure directing agents; specifically, any alkaline source conventionally used in the art for the purpose of making the system alkaline; more specifically, inorganic bases with alkali metal or alkaline earth metal cations, particularly sodium hydroxide and potassium hydroxide, etc. Here, "does not contain an alkaline source" means that no alkaline source is intentionally or actively introduced into the mixture.

[0174] In some embodiments, the crystallization process of the mixture is a rotating dynamic crystallization. In some embodiments, the rotation speed is 10 rpm to 60 rpm, for example, 20 rpm, 30 rpm, or 40 rpm.

[0175] In some embodiments, the crystallization process of the mixture is dynamic crystallization with stirring. In some embodiments, the stirring speed is 30 rpm to 400 rpm, for example, 50 rpm, 100 rpm, 150 rpm, 200 rpm, 250 rpm, 300 rpm, or 350 rpm.

[0176] In some embodiments, the crystallization conditions of the mixture are 130°C-180°C, for example, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, 165°C, 170°C, or 175°C, for 1-12 days, for example, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, or 11 days. In some embodiments, the crystallization conditions of the mixture are 135°C-175°C, for 2-11 days. In some embodiments, the crystallization conditions of the mixture are 140°C-170°C, for 3-10 days.

[0177] In some embodiments, the temperature of the hydrothermal treatment is 80°C-190°C, for example, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C or 180°C.

[0178] In some embodiments, the hydrothermal treatment time is 5h-48h, for example 8h, 10h, 12h, 15h, 20h, 24h, 28h, 30h, 32h, 36h, 40h, 44h or 46h.

[0179] According to the present invention, the various SCM-52 molecular sieve precursors obtained above can be used in any physical form, such as powder, granules, or molded products (e.g., strips, cloverleaf shapes, etc.). These physical forms can be obtained in any manner conventionally known in the art, without particular limitation.

[0180] Fourthly, the present invention provides a molecular sieve precursor composition comprising the SCM-52 molecular sieve precursor described in the first or second aspect or the SCM-52 molecular sieve precursor prepared by the preparation method described in the third aspect, and optionally a binder.

[0181] According to the present invention, the SCM-52 molecular sieve precursor can be used in combination with other materials to obtain an SCM-52 molecular sieve precursor composition. Examples of these other materials include active and inactive materials. Examples of active materials include synthetic zeolites, natural zeolites, or other types of molecular sieves, while examples of inactive materials (generally referred to as binders) include clay, kaolin, silica gel, and alumina. These other materials can be used individually or in combination in any proportion. The amount of these other materials used can be directly referenced from conventional amounts used in the art and is not particularly limited.

[0182] Fifthly, the present invention provides the use of the SCM-52 molecular sieve precursor described in the first or second aspect, or the SCM-52 molecular sieve precursor prepared by the preparation method described in the third aspect, or the molecular sieve composition described in the fourth aspect, as an adsorbent or a catalyst for the conversion of organic compounds or for the preparation of molecular sieves.

[0183] In some embodiments, the SCM-52 molecular sieve precursor can be used to prepare molecular sieves, for example, by calcination to prepare SCM-53 molecular sieves.

[0184] In some embodiments, the SCM-52 molecular sieve precursor or molecular sieve precursor composition is used to separate at least one component from a mixture of multiple components in a gas or 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-52 molecular sieve precursor or the molecular sieve precursor composition to selectively adsorb the component.

[0185] The SCM-52 molecular sieve precursor involved in this invention has a novel framework structure and / or chemical composition, and has very important application value. Attached Figure Description

[0186] Figure 1 The X-ray diffraction (XRD) pattern of the sample in Example 1;

[0187] Figure 2 The image shown is a scanning electron microscope (SEM) image of the sample in Example 1.

[0188] Figure 3 The sample in Example 1 27 Al NMR;

[0189] Figure 4 The sample in Example 1 29 Si NMR spectrum;

[0190] Figure 5 The X-ray diffraction (XRD) pattern of the sample in Example 2;

[0191] Figure 6 The image shown is a scanning electron microscope (SEM) image of the sample in Example 2.

[0192] Figure 7 The X-ray diffraction (XRD) pattern of the sample in Example 3;

[0193] Figure 8 This is a scanning electron microscope (SEM) image of the sample in Example 3. Detailed Implementation

[0194] The specific embodiments of the present invention will be described in detail below. However, it should be noted that the scope of protection of the present invention is not limited to these specific embodiments, but is determined by the claims in the appendix.

[0195] 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 in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0196] When this specification uses the prefixes “known to those skilled in the art,” “prior art,” or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0197] In the context of this specification, except where expressly stated, any matters or issues not mentioned herein shall apply directly to those known in the art without any modification. Furthermore, any implementation described herein may be freely combined with one or more other implementations described herein, and any resulting technical solutions or concepts shall be considered part of the original disclosure or original record of this invention, and should not be regarded as new content not disclosed or anticipated herein, unless those skilled in the art consider such combination to be clearly unreasonable.

[0198] In the context of this specification, in XRD data of molecular sieve precursors, w, m, s, and vs represent diffraction peak intensities, where w is weak, m is moderate, s is strong, and vs is very strong, as is well known to those skilled in the art. Generally, w is less than 20, for example, 5, 7, 10, 11, 12, 13, 14, 15, 16, 17, 18, or 19; m is 20–40, for example, 21, 23, 25, 27, 29, 30, 31, 33, 35, 37, or 39; s is 40–70, for example, 41, 43, 45, 47, 49, 50, 51, 53, 55, 57, 59, 60, 61, 63, 65, 67, or 69; and vs is greater than 70, for example, 75, 80, 85, 90, 95, or 100.

[0199] In the context of this specification, the structure of the molecular sieve precursor is determined by X-ray diffraction (XRD), which is measured using an X-ray powder diffractometer with a Cu-Kα ray source and a nickel filter. Before sample testing, the crystallinity of the molecular sieve precursor sample is observed using a scanning electron microscope (SEM) to confirm that the sample contains only one type of crystal, i.e., the molecular sieve precursor sample is a pure phase. XRD testing is then performed to ensure that there are no interfering peaks from other crystals in the diffraction pattern.

[0200] In some embodiments, the SCM-50 molecular sieve precursor of the present invention has Figure 1 , Figure 5 or Figure 7 The X-ray diffraction pattern shown.

[0201] In the context of this specification, including in the following examples and comparative examples, the X-ray powder diffractometer used for the molecular sieve precursor is a Panalytical X-RPERPRO type X-ray powder diffractometer, used to analyze the phase composition of the samples, and a CuKα ray source. Nickel filter, 2θ scanning range 2°-50°, operating voltage 40KV, current 40mA, scanning rate 10° / min.

[0202] In the context of this specification, including in the following examples and comparative examples, the scanning electron microscope (SEM) used to observe the molecular sieve precursor was a Model S-4800II field emission scanning electron microscope. The molecular sieve precursor was observed using this SEM at a magnification of 40,000x. A randomly selected field of view was used, and the average sum of the thicknesses of all crystals within that field of view was calculated. This operation was repeated a total of 10 times. The average sum of the 10 measurements was taken as the crystal thickness, and the size of all aggregates within that field of view was measured using the same method.

[0203] In the context of this specification, including in the following examples and comparative examples, the molecular sieve precursor was analyzed using an inductively coupled plasma atomic emission spectrometer (ICP) model Varian 725-ES, and the elemental content, in molar terms, was determined by dissolving the analytical sample in hydrofluoric acid.

[0204] In the context of this specification, including in the following examples and comparative examples, the solid-state nuclear magnetic resonance (NMR) instrument used for the molecular sieve precursor is a Bruker 600M, which will analyze the elemental coordination environment in the sample.

[0205] In the context of this specification, including in the following examples and comparative examples, the organic content in the molecular sieve precursor was determined by thermogravimetric analysis using an SDT Q600 V20.9Build 20 thermogravimetric analyzer. The sample was heated from 50°C to 800°C at a rate of 10°C / min in air or oxygen atmosphere to detect weight loss. The percentage of weight loss of the sample in the range of 200°C-700°C was taken as the organic content of the sample.

[0206] The technical solution of the present invention will be further described in detail below through embodiments, but the scope of protection of the present invention is not limited to these embodiments.

[0207] The preparation of 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide in this invention is carried out by the following method:

[0208] Preparation Example 1 Preparation

[0209] Mix 0.01 mol (98 wt%, 4.59 g) of 1,2,4,5-tetra(bromomethyl)benzene (CAS: 15442-91-8) and 300 mL of N,N-dimethylformamide (DMF) solvent, add 0.02 mol (98 wt%, 4.59 g) of anhydrous potassium carbonate as an acid-binding agent, and stir at 1000-1500 rpm until homogeneous. Under reflux, heat to 60-65 °C while stirring, then add 0.02 mol (10 mL) of dimethylamine (tetrahydrofuran solution of dimethylamine, 2 M) dropwise to the system at a constant pressure, controlling the dropping rate at 3-4 seconds / drop. After the addition is complete, continue reflux for 6-8 hours, and allow to stand to room temperature to obtain the reaction mixture. Cool the reaction mixture at 0 °C, then filter and separate, and distill the filtrate under reduced pressure. Recrystallize the concentrated solution with acetone, filter, and dry to obtain the target product, a nitrogen-containing heterocyclic quaternary ammonium salt:

[0210] Yield: 67.7%.

[0211] Preparation Example 2 Preparation

[0212] The nitrogen-containing heterocyclic quaternary ammonium salt (0.1 mol) obtained according to Preparation Example 1, water (125 g), and anion exchange resin (200 g) were stirred at room temperature for 12 h, and filtered to obtain 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide. Solution.

[0213] Example 1

[0214] 26.815 g of deionized water, 10.08 g of 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide solution (containing 20 wt% OSDA 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide), 15.023 g of silica sol (containing 40 wt% SiO2), and 2.637 g of aluminum hydroxide were mixed evenly and stirred at room temperature for 8 hours to obtain a mixture. The final material ratio (molar ratio) was: Al2O3 / SiO2 = 0.15, OSDA / SiO2 = 0.08, H2O / SiO2 = 25.

[0215] The mixture prepared above was placed in a stainless steel reactor and crystallized for 7 days at 150°C and 30 rpm. After crystallization, the mixture was centrifuged and washed until the pH value was near neutral (pH = 7-8), and then dried in an oven at 110°C to obtain aluminosilicates.

[0216] The aluminosilicate prepared above was subjected to silanization treatment. 10 g of aluminosilicate, 500 mL of 2 mol / L nitric acid solution, and 6 g of tetramethoxysilane (silanizing reagent SIL) were mixed and stirred at room temperature for 1.0 h. The mixture was then hydrothermally treated at 160 °C for 32 h. After treatment, the mixture was centrifuged and washed until the pH value was near neutral (pH = 7-8), and then dried in an oven at 110 °C to obtain 6.1 g of sample.

[0217] The XRD pattern of the sample is as follows Figure 1 As shown in Table 1, the precursor for SCM-52 molecular sieves was obtained in a yield of 61 wt%.

[0218] SEM images of the samples are as follows Figure 2 As shown, it has a nanosheet-like morphology.

[0219] The sample 27 Al NMR spectrum as shown Figure 3 As shown, 29 Si NMR spectrum as shown Figure 4 As shown, where, Figure 4 The peaks with chemical shifts of -14 ppm and -65 ppm correspond to the condensation between adjacent silanizing reagents attached to the outer surface, indicating that the silane group was successfully inserted into the molecular sieve precursor.

[0220] The molar ratio of silicon, aluminum, organic structure directing agent and silanizing agent in the sample was determined by inductively coupled plasma atomic emission spectrometry (ICP) and thermogravimetric analysis to be 1SiO2·0.02Al2O3·0.035OSDA·0.0018SIL.

[0221] Table 1

[0222]

[0223] Example 2

[0224] 33.80 g of deionized water, 2.637 g of 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide solution (containing 20 wt% OSDA 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide), 15.023 g of silica sol (containing 40 wt% SiO2), and 2.637 g of aluminum hydroxide were mixed evenly and stirred at room temperature for 7 hours to obtain a mixture. The final material ratio (molar ratio) was: Al2O3 / SiO2 = 0.15, OSDA / SiO2 = 0.1, H2O / SiO2 = 30.

[0225] The mixture prepared above was placed in a stainless steel reactor and crystallized for 5 days at 145°C and 30 rpm. After crystallization, the mixture was centrifuged and washed until the pH value was near neutral (pH = 7-8), and then dried in an oven at 110°C to obtain aluminosilicate.

[0226] The prepared aluminosilicate was subjected to silanization treatment. 10 g of aluminosilicate, 500 mL of 1.5 mol / L nitric acid solution, and 7.5 g of tetramethoxysilane (silanizing agent SIL) were mixed and stirred at room temperature for 1 h. The mixture was then hydrothermally treated at 165 °C for 24 h. After treatment, the mixture was centrifuged and washed until the pH was near neutral (pH = 7-8), and then dried in an oven at 120 °C to obtain 6.5 g of sample.

[0227] The XRD pattern of the sample is as follows Figure 5 As shown in Table 2, the precursor for SCM-52 molecular sieves was obtained in a yield of 65 wt%.

[0228] SEM images of the samples are as follows Figure 6 As shown, it has a nanosheet-like morphology.

[0229] Table 2

[0230]

[0231] The molar ratio of silicon, aluminum, organic structure directing agent and silanizing agent in the sample was determined by inductively coupled plasma atomic emission spectrometry (ICP) and thermogravimetric analysis to be 1SiO2·0.018Al2O3·0.037OSDA·0.0020SIL.

[0232] Example 3

[0233] 37.76 g of deionized water, 18.9 g of 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide solution (containing 20 wt% OSDA 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide), 15.023 g of silica sol (containing 40 wt% SiO2), and 1.758 g of aluminum hydroxide were mixed evenly and stirred at room temperature for 10 hours to obtain a mixture. The final material ratio (molar ratio) was: Al2O3 / SiO2 = 0.15, OSDA / SiO2 = 0.15, H2O / SiO2 = 35.

[0234] The mixture prepared above was placed in a stainless steel reactor and crystallized for 5 days at 150°C and 30 rpm. After crystallization, the mixture was centrifuged and washed until the pH value was near neutral (pH = 7-8), and then dried in an oven at 110°C to obtain aluminosilicates.

[0235] The prepared aluminosilicate was subjected to silanization treatment. 10 g of aluminosilicate, 400 mL of 2.5 mol / L nitric acid solution, and 4.5 g of tetramethoxysilane (silanizing reagent SIL) were mixed and stirred at room temperature for 1.0 h. The mixture was then hydrothermally treated at 150 °C for 24 h. After treatment, the mixture was centrifuged and washed until the pH was near neutral (pH = 7-8), and then dried in an oven at 110 °C to obtain 7.1 g of sample.

[0236] The XRD pattern of the sample is as follows Figure 7 As shown in Table 3, the precursor for SCM-52 molecular sieves was obtained in a yield of 71 wt%.

[0237] SEM images of the samples are as follows Figure 8 As shown, it has a nanosheet-like morphology.

[0238] Table 3

[0239]

[0240] The molar ratio of silicon, aluminum, organic structure directing agent and silanizing agent in the sample was determined by inductively coupled plasma atomic emission spectrometry (ICP) and thermogravimetric analysis to be 1SiO2·0.017Al2O3·0.042OSDA·0.0017SIL.

[0241] Example 4

[0242] 27.18 g of deionized water, 10.08 g of 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide solution (containing 20 wt% OSDA 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide), 15.03 g of silica sol (containing 40 wt% SiO2), and 1.758 g of aluminum hydroxide were mixed thoroughly and stirred at room temperature for 7 hours to obtain a mixture. The final material ratio (molar ratio) was: Al2O3 / SiO2 = 0.1, OSDA / SiO2 = 0.08, H2O / SiO2 = 25.

[0243] The mixture prepared above was placed in a stainless steel reactor and crystallized for 6 days at 160°C and 35 rpm. After crystallization, the mixture was centrifuged and washed until the pH value was near neutral (pH = 7-8), and then dried in an oven at 120°C to obtain prealuminosilicate.

[0244] The prepared aluminosilicate was subjected to silanization treatment. 10 g of aluminosilicate, 400 mL of 3 mol / L nitric acid solution, and 6 g of tetramethoxysilane (silanizing reagent SIL) were mixed and stirred at room temperature for 1.0 h. The mixture was then hydrothermally treated at 170 °C for 24 h. After treatment, the mixture was centrifuged and washed until the pH value was near neutral (pH = 7-8), and then dried in an oven at 110 °C to obtain 6.8 g of sample.

[0245] The XRD patterns of the samples are shown in Table 4. The samples are SCM-52 molecular sieve precursors, and the yield of the molecular sieve precursors is 68 wt%.

[0246] SEM images of the samples and Figure 2 Similarly, it has a nanosheet-like morphology.

[0247] Table 4

[0248]

[0249] The molar ratio of silicon, aluminum, organic structure directing agent and silanizing agent in the sample was determined by inductively coupled plasma atomic emission spectrometry (ICP) and thermogravimetric analysis to be 1SiO2·0.009Al2O3·0.028OSDA·0.0019SIL.

[0250] Example 5

[0251] 46.782 g of deionized water, 12.6 g of 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide solution (containing 20 wt% OSDA 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide), 20.833 g of tetraethyl orthosilicate (containing 28.8 wt% SiO2), and 1.758 g of aluminum isopropoxide were mixed evenly and stirred at room temperature for 7 hours to obtain a mixture. The final material ratio (molar ratio) was: Al2O3 / SiO2 = 0.1, OSDA / SiO2 = 0.1, H2O / SiO2 = 30.

[0252] The mixture prepared above was placed in a stainless steel reactor and crystallized for 7 days at 150°C and 30 rpm. After crystallization, the mixture was centrifuged and washed until the pH value was near neutral (pH = 7-8), and then dried in an oven at 110°C to obtain aluminosilicates.

[0253] The aluminosilicate was subjected to silanization treatment by mixing 10 g of aluminosilicate, 400 mL of 2 mol / L nitric acid solution, and 4.9 g of tetramethoxysilane (silanizing reagent SIL) at room temperature and stirring for 0.5 h. The mixture was then hydrothermally treated at 175 °C for 24 h. After treatment, the mixture was centrifuged and washed until the pH was near neutral (pH = 7–8), and then dried in an oven at 110 °C to obtain 7.2 g of sample.

[0254] The XRD patterns of the samples are shown in Table 5. The samples are SCM-52 molecular sieve precursors, and the yield of the molecular sieve precursors is 72 wt%.

[0255] SEM images of the samples and Figure 6 Similarly, it has a nanosheet-like morphology.

[0256] Table 5

[0257]

[0258] The molar ratio of silicon, aluminum, organic structure directing agent and silanizing agent in the sample was determined by inductively coupled plasma atomic emission spectrometry (ICP) and thermogravimetric analysis to be 1SiO2·0.0095Al2O3·0.029OSDA·0.0018SIL.

[0259] Example 6

[0260] 31.333 g of deionized water, 18.9 g of 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide solution (containing 20 wt% OSDA 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide), 6.009 g of silica (containing 100 wt% SiO2), and 1.367 g of alumina were mixed evenly and stirred at room temperature for 6 hours to obtain a mixture. The final material ratio (molar ratio) was: Al2O3 / SiO2 = 0.1, OSDA / SiO2 = 0.15, H2O / SiO2 = 35.

[0261] The mixture prepared above was placed in a stainless steel reactor and crystallized for 10 days at 135°C and 30 rpm. After crystallization, the mixture was centrifuged and washed until the pH value was near neutral (pH = 7-8), and then dried in an oven at 100°C to obtain aluminosilicates.

[0262] The prepared aluminosilicate was subjected to silanization treatment. 10 g of aluminosilicate, 500 mL of 2 mol / L nitric acid solution, and 8 g of tetramethoxysilane (silanizing reagent SIL) were mixed and stirred at room temperature for 1.0 h. The mixture was then hydrothermally treated at 165 °C for 24 h. After treatment, the mixture was centrifuged and washed until the pH was near neutral (pH = 7-8), and then dried in an oven at 110 °C to obtain 6.9 g of sample.

[0263] The XRD patterns of the samples are shown in Table 6. The samples are SCM-52 molecular sieve precursors, and the yield of the molecular sieve precursors is 69 wt%.

[0264] SEM images of the samples and Figure 6 Similarly, it has a nanosheet-like morphology.

[0265] Table 6

[0266]

[0267] The molar ratio of silicon, aluminum, organic structure directing agent and silanizing agent in the sample was determined by inductively coupled plasma atomic emission spectrometry (ICP) and thermogravimetric analysis to be 1SiO2·0.0093Al2O3·0.032OSDA·0.0025SIL.

[0268] Application examples

[0269] The SCM-52 molecular sieve precursor prepared in Example 1 was calcined at 550°C in an oxygen-containing atmosphere for 6 hours to obtain the sample. The XRD pattern of the sample is shown in Table 7, indicating that it is an SCM-53 molecular sieve.

[0270] Table 7

[0271]

[0272] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An SCM-52 molecular sieve precursor, comprising silica, alumina, an organic structure directing agent, and a silanizing agent, wherein the organic structure directing agent comprises a compound represented by Formula I. Equation I In Equation I, R1, R2, R3, and R4 may be the same or different, and each is independently selected from C. 1-8 Alkyl, X - Selected from OH - R5 and R6 may be the same or different, and each is independently selected from hydrogen, halogen, or carbon. 1-4 Alkyl groups; the X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes diffraction peaks at 2θ of 3.985°±0.30°, 8.306°±0.30°, 12.081°±0.30° and 25.921°±0.50°.

2. The SCM-52 molecular sieve precursor according to claim 1, characterized in that, R1, R2, R3, and R4 are each independently selected from C. 1-4 alkyl.

3. The SCM-52 molecular sieve precursor according to claim 2, characterized in that, R1, R2, R3 and R4 are each independently selected from methyl, ethyl or propyl.

4. The SCM-52 molecular sieve precursor according to claim 1, characterized in that, R5 and R6 are each independently hydrogen, fluorine, chlorine, bromine, methyl, ethyl, or propyl.

5. The SCM-52 molecular sieve precursor according to claim 1, characterized in that, The organic structure directing agent is selected from 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide.

6. The SCM-52 molecular sieve precursor according to claim 1, characterized in that, The strongest diffraction peak is the one with a 2θ of 3.985° ± 0.30°.

7. The SCM-52 molecular sieve precursor according to claim 1, characterized in that, The X-ray diffraction pattern of the SCM-52 molecular sieve precursor also includes one or more diffraction peaks with 2θ values ​​of 13.941°±0.30°, 17.88°±0.50°, 22.146°±0.50°, and 24.225°±0.30°.

8. The SCM-52 molecular sieve precursor according to claim 1, characterized in that, The X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table A: Table A 。 9. The SCM-52 molecular sieve precursor according to claim 8, characterized in that, The X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table B: Table B 。 10. The SCM-52 molecular sieve precursor according to claim 1, characterized in that, The X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table C: Table C b: varies with 2θ.

11. The SCM-52 molecular sieve precursor according to claim 10, characterized in that, The X-ray diffraction pattern of the SCM-52 molecular sieve precursor includes the diffraction peaks shown in Table D: Table D Where b: varies with 2θ.

12. The SCM-52 molecular sieve precursor according to claim 1, characterized in that, The SCM-52 molecular sieve precursor includes silicon, aluminum, oxygen, and nitrogen, and / or The silanizing agent includes compounds represented by Formula II. Formula II In Equation II, R7, R8, R9 and R 10 Whether the elements are the same or different, they are each independently selected from hydrogen, halogens, and carbon. 1-6 Alkyl, C 1-6 alkoxy; and / or In the SCM-52 molecular sieve precursor, the molar ratio of silicon dioxide to aluminum oxide is 10-500, the molar ratio of silicon dioxide to organic structure directing agent is 5-40, and the molar ratio of silicon dioxide to silanizing agent is 200-800.

13. The SCM-52 molecular sieve precursor according to claim 12, characterized in that, In Equation II, R7, R8, R9 and R 10 Each is independently selected from hydrogen, fluorine, chlorine, bromine, methyl, ethyl, propyl, methoxy, ethoxy, and propoxy.

14. The SCM-52 molecular sieve precursor according to claim 12, characterized in that, R7, R8, R9 and R 10 They are the same, both selected from C. 1-4 Alkyl group.

15. The SCM-52 molecular sieve precursor according to claim 12, characterized in that, The silanizing agent is selected from one or more of tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, monomethylchlorosilane, dimethylchlorosilane, monomethylmethoxysilane, dimethylmethoxysilane, monomethylethoxysilane, and dimethylethoxysilane.

16. The SCM-52 molecular sieve precursor according to claim 12, characterized in that, In the SCM-52 molecular sieve precursor, the molar ratio of silicon dioxide to aluminum oxide is 20-200, the molar ratio of silicon dioxide to organic structure directing agent is 20-40, and the molar ratio of silicon dioxide to silanizing agent is 300-600.

17. The SCM-52 molecular sieve precursor according to claim 12, characterized in that, The SCM-52 molecular sieve precursor has the following chemical composition in the following molar ratio: mSiO2•nAl2O3•qOSDA•ySIL, where OSDA represents an organic structure directing agent, SIL represents a silanizing agent, 10≤m / n≤500, 5≤m / q≤40, 200≤m / y≤800; and / or The SCM-52 molecular sieve precursor crystals have a nanosheet morphology, and the average thickness of the crystals is less than or equal to 30 nm; and / or The SCM-52 molecular sieve precursor also includes one or more elements selected from sodium, potassium, germanium, titanium, boron, zirconium, tin, and iron.

18. The SCM-52 molecular sieve precursor according to claim 17, characterized in that, The SCM-52 molecular sieve precursor has the following chemical composition in the following molar ratio: mSiO2•nAl2O3•qOSDA•ySIL, where OSDA represents an organic structure directing agent, SIL represents a silanizing agent, 20≤m / n≤200, 20≤m / q≤40, and 300≤m / y≤600.

19. The SCM-52 molecular sieve precursor according to claim 17, characterized in that, The average thickness of the SCM-52 molecular sieve precursor crystals is 2nm-27nm.

20. The SCM-52 molecular sieve precursor according to claim 17, characterized in that, The average thickness of the SCM-52 molecular sieve precursor crystals is 5nm-25nm.

21. A method for preparing the SCM-52 molecular sieve precursor according to any one of claims 1 to 20, comprising the following steps: S1: A mixture containing a silicon source, an aluminum source, an organic structure directing agent, and a solvent is subjected to crystallization treatment to obtain a crystallized product; S2: Under acidic conditions, the crystallized product is mixed with a silanizing agent and then subjected to hydrothermal treatment; the organic structure directing agent includes compounds represented by Formula I. Equation I In Equation I, R1, R2, R3, and R4 may be the same or different, and each is independently selected from C. 1-8 Alkyl; X - Selected from OH - R5 and R6 may be the same or different, and each is independently selected from hydrogen, halogen, or carbon. 1-4 alkyl.

22. The preparation method according to claim 21, characterized in that, R1, R2, R3, and R4 are each independently selected from C. 1-4 alkyl.

23. The preparation method according to claim 22, characterized in that, R1, R2, R3 and R4 are each independently selected from methyl, ethyl or propyl.

24. The preparation method according to claim 21, characterized in that, R5 and R6 are each independently hydrogen, fluorine, chlorine, bromine, methyl, ethyl, or propyl.

25. The preparation method according to claim 21, characterized in that, The organic structure directing agent is selected from 2,2,6,6-tetramethyl-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole ammonium hydroxide.

26. The preparation method according to claim 21, characterized in that, The silicon source is calculated as SiO2 and the aluminum source is calculated as Al2O3, and the molar ratio of the silicon source to the aluminum source is 1:(0.0025-0.25). The molar ratio of the silicon source to the organic structure directing agent is 1:(0.050-0.50); The molar ratio of the silicon source to the solvent is 1:(8-100); and / or The acidic conditions are provided by an acidic solution.

27. The preparation method according to claim 26, characterized in that, The silicon source is calculated as SiO2 and the aluminum source is calculated as Al2O3, and the molar ratio of the silicon source to the aluminum source is 1:(0.025-0.2). The molar ratio of the silicon source to the organic structure directing agent is 1:(0.10-0.50); The molar ratio of the silicon source to the solvent is 1:(15-100).

28. The preparation method according to claim 27, characterized in that, The silicon source is calculated as SiO2 and the aluminum source is calculated as Al2O3, and the molar ratio of the silicon source to the aluminum source is 1:(0.0025-0.15). The molar ratio of the silicon source to the organic structure directing agent is 1:(0.30-0.50); The molar ratio of the silicon source to the solvent is 1:(15-50).

29. The preparation method according to claim 26, characterized in that, The concentration of the acid solution is 0.5 mol / L to 6 mol / L.

30. The preparation method according to claim 29, characterized in that, The concentration of the acid solution is 1 mol / L to 5 mol / L.

31. The preparation method according to claim 30, characterized in that, The concentration of the acid solution is 1.5 mol / L to 4.5 mol / L.

32. The preparation method according to claim 26, characterized in that, The liquid-to-solid ratio of the acid solution to the crystallized product is (10-100) mL:1 g.

33. The preparation method according to claim 32, characterized in that, The liquid-to-solid ratio of the acid solution to the crystallized product is (20-80) mL:1 g.

34. The preparation method according to claim 33, characterized in that, The liquid-to-solid ratio of the acid solution to the crystallized product is (40-60) mL:1 g.

35. The preparation method according to claim 26, characterized in that, The mass ratio of the silanizing agent to the crystallized product is (0.1-4):

1.

36. The preparation method according to claim 35, characterized in that, The mass ratio of the silanizing agent to the crystallized product is (0.2-2.5):

1.

37. The preparation method according to claim 26, characterized in that, The acid solution is selected from hydrochloric acid, acetic acid, or an aqueous or ethanolic solution of nitric acid; and / or The silanizing agent includes compounds represented by Formula II. Formula II In Equation II, R7, R8, R9 and R 10 Whether the elements are the same or different, they are each independently selected from hydrogen, halogens, and carbon. 1-6 Alkyl, C 1-6 alkoxy; and / or The silicon source is selected from one or more of silica sol, silica gel, tetraethyl orthosilicate, silica fume, and silicic acid; and / or The aluminum source is selected from one or more of aluminum hydroxide, aluminum isopropoxide, aluminum nitrate, and aluminum oxide; and / or The solvent is selected from water; and / or The mixture does not contain alkali metals or alkaline earth metals.

38. The preparation method according to claim 37, characterized in that, In Equation II, R7, R8, R9 and R 10 Each is independently selected from hydrogen, fluorine, chlorine, bromine, methyl, ethyl, propyl, methoxy, ethoxy, and propoxy.

39. The preparation method according to claim 37, characterized in that, R7, R8, R9 and R 10 They are the same, both selected from C. 1-4 Alkyl group.

40. The preparation method according to claim 37, characterized in that, The silanizing agent is selected from one or more of tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, monomethylchlorosilane, dimethylchlorosilane, monomethylmethoxysilane, dimethylmethoxysilane, monomethylethoxysilane, and dimethylethoxysilane.

41. The preparation method according to claim 21, characterized in that, The crystallization process of the mixture is dynamic crystallization by rotation or stirring, with a rotation speed of 10 rpm-60 rpm and a stirring speed of 30 rpm-400 rpm; the crystallization conditions of the mixture are crystallization at 130℃-180℃ for 1-12 days; and / or The hydrothermal treatment temperature is 80℃-190℃; and / or The hydrothermal treatment time is 5h-48h.

42. The preparation method according to claim 41, characterized in that, The mixture is crystallized at 135℃-175℃ for 2-11 days.

43. The preparation method according to claim 42, characterized in that, The crystallization conditions for the mixture are 140℃-170℃ for 3-10 days.

44. A molecular sieve precursor composition comprising the SCM-52 molecular sieve precursor according to any one of claims 1-20 or the SCM-52 molecular sieve precursor prepared by the preparation method according to any one of claims 21-43, and optionally a binder.

45. The SCM-52 molecular sieve precursor according to any one of claims 1-20, or the SCM-52 molecular sieve precursor prepared by the preparation method according to any one of claims 21-43, or the molecular sieve precursor composition according to claim 44, as an adsorbent or catalyst for the conversion of organic compounds or for the preparation of molecular sieves.

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