Silicate materials ZEO-2 and silicate molecular sieves ZEO-3, as well as methods for their synthesis and their use

Abstract

The present invention relates to a one-dimensional silicate material ZEO-2 with a novel structure, and a three-dimensional silicate molecular sieve ZEO-3 obtained by roasting ZEO-2, as well as their synthesis methods and uses. The powder X-ray diffraction characteristics and crystal structures of the two silicate materials are presented. The one-dimensional silicate ZEO-2 can be synthesized by a simple method. The molecular sieve ZEO-3 can be obtained by calcining the one-dimensional silicate ZEO-2 to cause topological condensation. ZEO-2 can be used as a silicon source or precursor in the synthesis of new molecular sieves. The molecular sieve ZEO-3 has good thermal stability and can be used as an adsorbent or catalyst.

Description

[Technical field]

[0001] The present invention relates to the technical field of inorganic synthesis and its chemical applications, in particular to a one-dimensional silicate material ZEO-2 having a novel structure, and a three-dimensional silicate molecular sieve ZEO-3 obtained by calcining the same, as well as to a method for synthesizing and using them. [Background technology]

[0002] In industry, microporous silicate materials are widely used in the fields of catalysis, adsorption separation, etc. Microporous silicate materials have a large specific surface area, no blockage in the channel structure, and excellent thermal stability, making them excellent catalyst materials, catalyst supports, or adsorption separation materials.

[0003] Crystalline microporous silicate materials are also called zeolite molecular sieves. Their basic framework structure is composed of TO4 (SiO4, AlO4, etc.) units. TO4 has a tetrahedral structure in which oxygen atoms are shared. The charge balance of framework tetrahedra such as AlO4 is achieved by the H in the channels. + , Na + , and K +The zeolite molecular sieve structure is rich in channel systems with specific channel diameters. These channels cross each other and can form various three-dimensional network structures. According to the channel size, micropore zeolite molecular sieves can be divided into small pore, medium pore, large pore, and ultra-large pore molecular sieves, corresponding to the number of TO4 at the pore entrance being 8-membered rings or less, 10-membered rings or less, 12-membered rings or less, and more than 12-membered rings. On the one hand, precisely because of the above channel structure, zeolite molecular sieves have good catalytic activity, good shape selectivity, and good selective adsorption performance for various organic reactions; on the other hand, due to the difference in structure, zeolite molecular sieve materials with different channel structures have significantly different properties such as catalysis and adsorption separation, as well as basic physical parameters used to characterize materials, such as morphology, specific surface area, pore size distribution, and pore volume.

[0004] Currently, the molecular sieve materials successfully used in industry have channel diameters that are usually less than 1 nm, which greatly limits the size and shape of substrate molecules in adsorption, separation, and catalytic processes. The development and availability of stable ultra-large pore molecular sieves with channel diameters of 1-2 nm and channel rings of more than 12 rings would be of great application value in the fields of petrochemistry, fine chemicals, and life sciences.

[0005] Zeolite molecular sieves with specific structures need to be further differentiated by powder X-ray diffraction: due to their different crystal structures, different molecular sieves have different channel structures and give completely different diffraction patterns in powder X-ray diffraction tests. Existing molecular sieves, such as A-type zeolite molecular sieve (see U.S. Pat. No. 2,882,243), Y-type zeolite molecular sieve (see U.S. Pat. No. 3,130,007), ZSM-11 zeolite molecular sieve (see U.S. Pat. No. 3,709,979), ZSM-12 zeolite molecular sieve (see U.S. Pat. No. 3,832,449), ZSM-23 zeolite molecular sieve (see U.S. Pat. No. 4,076,842), ZSM-35 zeolite molecular sieve (see U.S. Pat. No. 4,016,245), and MCM-42 zeolite molecular sieve (see U.S. Pat. No. 4,954,325), each exhibit a unique, characteristic powder X-ray diffraction pattern.

[0006] In addition, the uniqueness of molecular sieve materials with different structures may also be reflected in their unique topological properties. According to the definition and interpretation by the International Zeolite Association's Structure Committee, in the topological framework of a particular molecular sieve, the combination of coordination sequence and vertex symbols is unique, that is, it can be used to clearly distinguish different molecular sieve framework structures (see the official website of the International Zeolite Association: https: / / europe.iza-structure.org / IZA-SC / DatabaseHelp_Structures.html#CS).

[0007] The typical preparation method of silicate zeolite molecular sieve is to mix silicon source, heteroatom (Al, B, Ti, Sn, Ge, etc.), organic template, water, and mineralizer for high temperature crystallization, and then calcinate at high temperature to remove the organic template. With the development of zeolite molecular sieve synthesis technology, using known silicate materials as precursors and obtaining microporous silicate zeolite molecular sieves through post-treatment has also become another important method to develop molecular sieve materials with novel structures (see Chem. Soc. Rev., 2015, 44, 7177-7206, China Patent Publication No. 105728034).

[0008] Currently, all precursors available for the synthesis of novel microporous silicate zeolite molecular sieves have two-dimensional layered structures characterized by hydrogen bonds or van der Waals interactions between layers, which means that the bonds are not strong, and they exhibit structural diversity and processability, allowing for structural post-treatments and modifications such as expansion, pillaring, exfoliation, or silicon insertion for pore enlargement (see Chem. Rev., 2014, 114, 4807-4837). The layered silicate precursors can be prepared by direct synthesis via hydrothermal methods or by post-treatment of three-dimensional silicate zeolite materials (mainly silicogermanium zeolites).

[0009] There are two ways to obtain microporous silicate zeolite molecular sieves from layered silicate precursors. One is to calcinate the layered precursors to remove the organic template and dehydrate and condense the interlayer terminal silanol groups to form zeolite molecular sieve materials with three-dimensional structure. For example, MWW and FER zeolites can be directly synthesized by calcining the layered precursors MCM-22P and PREFER, respectively (see U.S. Pat. No. 4,954,325; Micro. Mater. 1 996, 6, 259-271). The other method is pore enlargement by silicon insertion. This uses an organosilane reagent as a bridging group to be inserted into the layers of the layered silicate precursors in an ordered and controllable manner, thereby expanding the interlayer spacing of the original layers and bonding the layers together, and the organic components can be removed by subsequent calcination. This method converts the 2D layered structure into a 3D microporous structure and improves the stability and crystallinity of the molecular sieve framework. Furthermore, the availability of multiple organosilane reagents allows for tuning and control of the channel size, shape, openness, and functionality of the zeolite molecular sieve products, which greatly expands the structural chemistry of zeolite molecular sieves and their potential applications in heterogeneous catalysis involving polymers (see J. Am. Chem. Soc., 2008, 130, 8178-8187; Angew.Chem.Int.Ed., 2018, 130, 9659-9663).

[0010] It is clear that we can design the structure and function starting from silicate precursors. This is a very important and unique method for synthesizing microporous silicate zeolite molecular sieves. However, at present, the silicate precursors available for such a method are limited to a small number of layered structures, and there is no precedent for synthesizing silicate zeolite molecular sieves from one-dimensional chain precursors.

[0011] Therefore, the development of novel silicate precursor materials, especially precursors with one-dimensional chain structures, and their application in the development of novel zeolite molecular sieves is of great theoretical significance and important application value for the synthesis, structure, and application in the field of zeolite molecular sieves. Summary of the Invention

[0012] In the first aspect, the present invention provides a novel silicate material ZEO-2 with one-dimensional chain structure, and a three-dimensional silicate molecular sieve ZEO-3 obtained by calcining ZEO-2. These are two novel silicate materials that are pure silicon without germanium and have ultra-high thermal stability and hydrothermal stability. They are not only of great practical value, but also of great theoretical significance for the expansion of the molecular sieve structure family.

[0013] The chains of the one-dimensional chain silicate material ZEO-2 are separated by a template with a positive charge. There is no chemical bond between the template and the silicate chain. The chain structure has only silicon hydroxyl groups and silicon-oxygen-silicon bonds that extend infinitely. Organic matter exists in the ZEO-2 material, but does not form bonds or have strong interactions with the main body of the ZEO-2 material, i.e., the one-dimensional chain silicate. The molecular sieve ZEO-3 obtained after calcination is a three-dimensional ultra-large pore silicate molecular sieve material. All organic matter is removed during the calcination process. The one-dimensional chain silicate structure is topologically condensed to form a three-dimensional molecular sieve, and the small amount of inorganic matter in it can be removed by washing with water. The skeleton of ZEO-3 has only silicon-oxygen-silicon bonds that extend infinitely. The silicate material ZEO-2 having a one-dimensional chain structure of the present invention has the powder X-ray diffraction characteristics shown in Table 1.

[0014] [Table 1]

[0015] In the above data, w, mw, m, s, and vs represent diffraction peak intensities, where w is weak, mw is slightly weak, m is moderate, s is strong, and vs is very strong, as known to those skilled in the art. Typically, w is less than 10, mw is 10-20, m is 20-40, s is 40-70, and vs is greater than 70.

[0016] The silicate molecular sieve ZEO-3 having a three-dimensional ultra-large pore structure of the present invention has the powder X-ray diffraction characteristics shown in Table 2.

[0017] [Table 2]

[0018] In the above data, w, mw, m, s, and vs represent diffraction peak intensities, where w is weak, mw is slightly weak, m is moderate, s is strong, and vs is very strong, as known to those skilled in the art. Typically, w is less than 10, mw is 10-20, m is 20-40, s is 40-70, and vs is greater than 70.

[0019] In a second aspect, the present invention further provides a method for preparing the above one-dimensional silicate material ZEO-2 and the three-dimensional ultra-large pore molecular sieve ZEO-3.

[0020] The method for synthesizing the silicate material ZEO-2 is as follows: (1) mixing a silicon source, an organic template, and water to obtain a mixture; (2) crystallizing the mixture to obtain the one-dimensional silicate material ZEO-2; wherein the organic template has a tetrahedral topology represented by the general formula:

[0021] [ka] In the formula, R1 is cyclohexyl, R2 and R3 are phenyl or cyclohexyl, and R4 is C 1-8 Alkyl, preferably C 1-4Alkyl, more preferably C 1-2 alkyl, n has a value of 3 to 8, preferably 5 to 7, more preferably 6, and X is phosphorus or nitrogen, preferably phosphorus.

[0022] The method for synthesizing the molecular sieve ZEO-3 includes calcining the silicate material ZEO-2 of the present invention to remove the template and cause topological condensation of the framework structure, thereby obtaining the three-dimensional ultra-large pore zeolite molecular sieve ZEO-3 of the present invention.

[0023] In a third aspect, the present invention further provides a molecular sieve composition comprising the three-dimensional extra-large pore silicate molecular sieve ZEO-3 of the present invention and a binder.

[0024] In a fourth embodiment, the one-dimensional silicate material ZEO-2 of the present invention can be used as a silicon source or precursor in molecular sieve synthesis, and the three-dimensional extra-large silicate molecular sieve ZEO-3 can be used as a catalyst or adsorbent. [Brief description of the drawings]

[0025] [Figure 1] 1 shows a powder X-ray diffraction pattern of the silicate material ZEO-2 of the present invention (light source: Cu target Kα ray). [Diagram 2] 1 is a powder X-ray diffraction pattern of the silicate molecular sieve ZEO-3 of the present invention (light source is Cu target Kα radiation). [Diagram 3] 1 is a comparison of the relative intensities of powder X-ray diffraction patterns of the silicate material ZEO-2 of the present invention and the silicate molecular sieve ZEO-3. [Figure 4] 1 is a scanning electron microscope (SEM) image of the silicate material ZEO-2 of the present invention. [Diagram 5] 1 is a scanning electron microscope (SEM) image of the silicate molecular sieve ZEO-3 of the present invention. [Figure 6] FIG. 1 is a diagram of the framework structure of the silicate material ZEO-2 after removal of the organic template. [Figure 7] FIG. 1 is a diagram of the channel structure of the ultra-large pore molecular sieve ZEO-3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] The crystal structure of the inorganic framework of the silicate material ZEO-2 of the present invention is shown in Figure 6. The crystal structure of the silicate material ZEO-2 has a regular long-range ordered one-dimensional silica chain structure that extends infinitely in the c-axis direction.

[0027] The crystal structure of the molecular sieve ZEO-3 of the present invention is shown in Figure 7. As can be seen from Figure 7, there are 14-ring channels penetrating the ZEO-3 crystal structure in both the (a+b) and (ab) axis directions. In addition, there are 16-ring channels in the c-axis direction of the ZEO-3 crystal structure. Therefore, this structure is referred to as a three-dimensional intersecting channel system of 16 x 14 x 14 rings.

[0028] The molecular sieve ZEO-3 of the present invention was subjected to structural and topological analysis. The molecular sieve framework structure has 11 topologically independent T atoms, 20 topologically different edges (lines formed by adjacent T atoms and T atoms), 16 topologically different faces (faces formed by T atoms), and 8 topologically different components formed by T atoms. Among these, the topological properties (such as the coordination sequence and vertex symbols) of the 11 topologically independent T atoms in the framework structure of the molecular sieve ZEO-3 are shown in Table 3.

[0029] [Table 3]

[0030] In the table, T1 to T11 represent 11 topologically distinct T atoms in the framework structure of the ultra-large pore molecular sieve ZEO-3 of the present invention, and N1 to N12 represent the coordination arrangement of these T atoms from the 1st layer to the 12th layer. Because the naming order of the T atoms is different, the topologically independent 11 T atoms named in different orders may not correspond one-to-one to the coordination arrangement and vertex symbols of the T atoms in the order of this table. However, all and only those structures belonging to the ZEO-3 topology contain the coordination arrangement and vertex symbols of the topologically independent 11 T atoms in this table, and the coordination arrangement and vertex symbols correspond one-to-one.

[0031] The silicate ZEO-2 of the present invention has the chemical composition SiO 2.2 H 0.4 (OSDA) y where OSDA is an organic template and y=0.075-0.125.

[0032] The extra-large pore silicate molecular sieve ZEO-3 of the present invention has a chemical composition of SiO2.

[0033] In the method for synthesizing the silicate material ZEO-2 of the present invention, specific examples of the organic template include, but are not limited to, any one or more of those shown in Table 4.

[0034] [Table 4]

[0035] The organic template is preferably any one or more selected from the group consisting of template 1, template 6, template 8, and template 10, more preferably any one or more selected from the group consisting of template 6 and template 10.

[0036] In the method for synthesizing the silicate material ZEO-2 of the present invention, step (1) specifically includes mixing a silicon source, an organic template, and water in a certain ratio to be homogeneous while statically or dynamically stirring, and using the resulting mixture to produce a compound represented by the formula: rROH:SiO2:wH2O The method may further include forming a reaction gel having a chemical composition represented by the formula: In the above formula, R represents a positively charged group of the organic template, and the corresponding value ranges of r and w are r=0.05-5.0 and w=1-100. Step (2) may specifically include placing the reaction gel under an infrared lamp or in an oven, removing excess solvent, and then transferring the reaction gel to a stainless steel reaction kettle, and reacting in a sealed state at a temperature of 80-240°C, preferably 120-220°C, for 1-60 days, preferably 2-45 days, to crystallize. The method may further include (2) washing, centrifuging and drying the crystallized product to obtain a silicate material ZEO-2 product.

[0037] In step (1), in the chemical composition of the reaction gel rROH:SiO2:wH2O, the corresponding value ranges of r and w are preferably r=0.1-2.0 and w=1-30.

[0038] The silicon source may be at least one selected from the group consisting of silicic acid, silica gel, silica sol, tetraalkyl silicate, and water glass, and may be preferably water glass, silica sol, or tetraethyl orthosilicate.

[0039] The preparation method of the present invention does not use germanium or germanium-containing compounds.

[0040] Prior to preparation of the reaction gel, all organic cation templates can be exchanged into the hydroxide form via ion exchange resins and their concentrations calibrated with 0.1 M hydrochloric acid solution for later use, or they can be directly introduced in the form of chloride, bromide, or iodide salts.

[0041] The crystallization conditions in step (2) may be, for example, a crystallization temperature of 80 to 240°C, preferably 120 to 220°C, and more preferably 140 to 210°C, and a crystallization time of 1 to 60 days, preferably 2 to 50 days, and more preferably 3 to 45 days.

[0042] In step (3), washing, centrifugation, and drying may be performed by any method conventionally known in the art, for example, washing may be performed multiple times with water or ethanol, and drying may be performed by oven drying.

[0043] In the method for synthesizing the extra-large pore zeolite molecular sieve ZEO-3 of the present invention, the calcination temperature is 300 to 1000°C.

[0044] The binder in the molecular sieve composition of the present invention may be any binder known in the art that can be used as a catalyst or adsorbent, so long as it does not adversely affect the molecular sieve ZEO-3 of the present invention. EXAMPLES

[0045] In order to more clearly illustrate the present invention, the following examples are provided, which are not intended to limit the scope of protection of the present invention in any way.

[0046] Example 1 Preparation of templates The general synthesis process of the template is described using template 6 as an example. 28.04g of tricyclohexylphosphine and 150mL of acetonitrile were mixed in a 250mL round-bottom flask. 21.29g of methyl iodide was added dropwise to the mixture at room temperature. The system was reacted for 2 days with stirring at room temperature, and the solvent was removed from the reaction mixture using a rotary evaporator to obtain a crude product, which was then recrystallized from ethanol to obtain 40.55g of product with a yield of 96%. The product was characterized by liquid NMR (CDCl3) and electrospray mass spectrometry, and was confirmed to be the target compound.

[0047] The resulting product was dispersed in 400 mL of deionized water, and the pretreated 717 strong base anion exchange resin (Sinopharm Group, China) was used for column exchange to exchange the resulting aqueous solution of template 6. An appropriate amount of this solution was weighed and calibrated with 0.1 mol / L hydrochloric acid solution using phenolphthalein as an indicator. The calibrated structure was confirmed to have an exchange efficiency from iodide salt to hydroxyl radical of up to 97%.

[0048] Example 2 Preparation of templates The general synthesis process of the template is described by taking template 10 as an example. 28.04g of tricyclohexylphosphine and 150mL of acetonitrile were mixed in a 250mL round-bottom flask. 12.20g of 1,6-dibromohexane was added dropwise to the mixture. The system was reacted under reflux with stirring for 2 days, and the solvent was removed from the reaction mixture by rotary evaporator to obtain the crude product, which was then recrystallized from ethanol to obtain 38.23g of product in 95% yield. The product was characterized by liquid NMR (D2O) and electrospray mass spectrometry and confirmed to be the target compound.

[0049] The resulting product was dispersed in 400 mL of deionized water, and the pretreated 717 strong base anion exchange resin (Sinopharm Group, China) was used for column exchange to exchange the resulting aqueous solution of template 10. An appropriate amount of this solution was weighed and calibrated with 0.1 mol / L hydrochloric acid solution using phenolphthalein as an indicator. The calibrated structure was confirmed to have an exchange efficiency from iodide salt to hydroxyl radical of up to 96%.

[0050] Example 3 Preparation of ZEO-2 and ZEO-3 According to the molar ratio of 0.5ROH:SiO2:10H2O, the gel for synthesis of molecular sieves was prepared by the following general procedure. An appropriate amount of the template solution of Example 1 after exchange was weighed, 4 mmol (0.833 g) of tetraethyl orthosilicate was added thereto, and the mixture was stirred at room temperature for about 2 hours to completely dissolve the tetraethyl orthosilicate, and then the mixed gel was placed under an infrared lamp or in an oven at 80 ° C to remove excess solvent. The final reaction gel was transferred to a 5 mL stainless steel reaction kettle with an inner shell of polytetrafluoroethylene, and reacted at 175 ° C for 28 days in a sealed state, and the product was washed twice with water and twice with ethanol, dried in an oven, and used. The product was directly phase identified by powder X-ray diffraction and confirmed to be ZEO-2.

[0051] A suitable amount of sample was calcined in a muffle furnace under air atmosphere at 600℃ for 2 hours. After removing the template, the product was washed with water, centrifuged and dried. The product was phase identified by powder X-ray diffraction and confirmed to be ZEO-3. EDS elemental analysis showed that it had silicon and oxygen elements, with the molecular formula of SiO2.

[0052] Example 4 Preparation of ZEO-2 and ZEO-3 According to the molar ratio of 0.3ROH:SiO2:5H2O, the gel for synthesis of molecular sieves was prepared by the following general procedure. An appropriate amount of the template solution of Example 2 after exchange was weighed, 2 mmol (0.417 g) of tetraethyl orthosilicate was added thereto, and the mixture was stirred at room temperature for about 2 hours to completely dissolve the tetraethyl orthosilicate, and then the mixed gel was placed under an infrared lamp or in an oven at 80 ° C to remove excess solvent. The final reaction gel was transferred to a 5 mL stainless steel reaction kettle with an inner shell of polytetrafluoroethylene, and reacted at 175 ° C for 30 days in a sealed state, and the product was washed twice with water and twice with ethanol, dried in an oven, and used. The product was directly phase identified by powder X-ray diffraction and confirmed to be ZEO-2.

[0053] A suitable amount of sample was calcined in a muffle furnace under air atmosphere at 600℃ for 2 hours. After removing the template, the product was washed with water, centrifuged and dried. The product was phase identified by powder X-ray diffraction and confirmed to be ZEO-3. EDS elemental analysis showed that it had silicon and oxygen elements, with the molecular formula of SiO2.

[0054] Example 5 Preparation of ZEO-2 and ZEO-3 According to the molar ratio of 0.5ROH:SiO2:10H2O, the gel for the synthesis of molecular sieves was prepared by the following general procedure. An appropriate amount of template 8 solution in Table 6 after exchange was weighed out, 1 mmol (0.208 g) of tetraethyl orthosilicate was added thereto, and the mixture was stirred at room temperature for about 2 hours to completely dissolve tetraethyl orthosilicate, and then the mixed gel was placed under an infrared lamp or in an oven at 80 ° C to remove excess solvent. The final reaction gel was transferred to a 5 mL stainless steel reaction kettle with an inner shell of polytetrafluoroethylene, and reacted at 175 ° C for 38 days in a sealed state. The product was washed twice with water and twice with ethanol, and dried in an oven for use. The product was directly phase identified by powder X-ray diffraction and confirmed to be ZEO-2.

[0055] A suitable amount of sample was calcined in a muffle furnace under air atmosphere at 600℃ for 2 hours. After removing the template, the product was washed with water, centrifuged and dried. The product was phase identified by powder X-ray diffraction and confirmed to be ZEO-3. EDS elemental analysis showed that it had silicon and oxygen elements, with the molecular formula of SiO2.

[0056] Example 6 Preparation of ZEO-2 and ZEO-3 According to the molar ratio of 0.5ROH:SiO2:10H2O, the gel for synthesis of molecular sieves was prepared by the following general procedure. 6 mmol of the template solution of Example 1 after exchange was weighed, 12 mmol (2.500 g) of tetraethyl orthosilicate was added thereto, and the mixture was stirred at room temperature overnight to completely hydrolyze tetraethyl orthosilicate, and the ethanol of the hydrolysis product was volatilized, and the mixed gel was placed under an infrared lamp or in an oven at 85 ° C to remove excess solvent. The final reaction gel was transferred to a 30 mL stainless steel reaction kettle with an inner shell of polytetrafluoroethylene, and reacted at 190 ° C for 30 days in a sealed state, and the product was washed twice with water and twice with ethanol, and dried in an oven for use. The product was directly phase identified by powder X-ray diffraction and confirmed to be ZEO-2. EDS elemental analysis showed that it had silicon, phosphorus, oxygen, and carbon elements. The Fourier transform infrared spectrum data showed that there was a strong peak of Si-OH bond stretching vibration, indicating that ZEO-2 was a type of silicate material with silanol groups and had a high content of silanol groups.

[0057] A suitable amount of sample was calcined in a muffle furnace under air atmosphere at 600℃ for 2 hours. After removing the template, the product was washed with water, centrifuged and dried. The product was phase identified by powder X-ray diffraction and confirmed to be ZEO-3. EDS elemental analysis showed that it only had silicon and oxygen elements, and the molecular formula was SiO2. Fourier transform infrared spectrum data showed that there was no Si-OH bond stretching vibration, only Si-O bond stretching vibration, indicating that ZEO-3 is a kind of silicate material without silanol groups and without defects.

[0058] Example 7 Structural analysis Continuous rotation electron diffraction (cRED) studies were performed on the molecular sieves ZEO-2 of Examples 3 to 6. The structural analysis results showed that the ZEO-2 molecular sieve structure has monoclinic symmetry with the C2 / c space group, and the unit cell parameters (Figure 1) obtained after powder X-ray refinement using a copper target (Kα) as a source are a = 23.539(9) Å, b = 24.744(9) Å, c = 14.398(9) Å, β = 115.19(9)°.

[0059] Continuous rotation electron diffraction (cRED) studies were performed on the molecular sieves ZEO-3 of Examples 3 to 6. The structural analysis results showed that the ZEO-3 molecular sieve structure has monoclinic symmetry with a C2 / c space group, and the unit cell parameters (Figure 2) obtained after powder X-ray refinement using a copper target (Kα) as a source were a = 21.505(9) Å, b = 21.274(9) Å, c = 14.463(9) Å, β = 108.72(9)°.

[0060] Topology analysis was performed using the crystallographic information file (CIF file) obtained after the cRED test. The topology analysis software used was ToposPro5.3.0.2, and the analysis procedures and methods were in accordance with the operation manual posted on the official website of the software (see ToposPro official website: https: / / topospro.com / software / ).

[0061] The analysis of the crystal structure of ZEO-3 showed that the framework structure of the molecular sieve had 11 topologically independent T atoms, 20 topologically different edges, 16 topologically different faces, and 8 topologically different building blocks composed of T atoms. More specific topological features of the framework structure of the ZEO-3 molecular sieve are shown in Table 3 above.

Claims

1. A silicate material having the powder X-ray diffraction characteristics shown in the table below. 【Table 1】

2. 2. The silicate material of claim 1, wherein the crystal structure of the silicate material has a regular long-range ordered one-dimensional silica chain structure.

3. The silicate material has the chemical composition SiO ２．２ H ０．４ ・(OSDA) ｙ and the OSDA has the following general formula: 【Chemistry 1】 (In the formula, R １ is cyclohexyl, R ２ and R ３ is phenyl or cyclohexyl; R ４ is C １－８ alkyl, n=3-8, and X is phosphorus or nitrogen. is an organic template having a tetrahedral spatial arrangement represented by y=0.075 to 0.125; 3. The silicate material according to claim 1 or 2.

4. A silicate molecular sieve having the powder X-ray diffraction characteristics shown in the table below. 【Table 2】

5. 5. The molecular sieve of claim 4, having a three-dimensional intersecting channel system of 16x14x14 rings in its crystal structure.

6. The T atoms in the framework of the molecular sieve are as shown in the following table: 【Table 3】 and T=Si.

6. The molecular sieve of claim 4 or 5.

7. SiO ２ 6. The molecular sieve of claim 4 or 5, having a chemical composition:

8. A method for synthesizing the silicate material of claim 1 or 2, comprising: (1) mixing a silicon source, an organic template, and water to obtain a mixture; (2) crystallizing the mixture to obtain the silicate material product; Including, The organic template has the following general formula: 【Chemistry 2】 (In the formula, R １ is cyclohexyl, R ２ and R ３ is phenyl or cyclohexyl; R ４ is C 1-8 alkyl, n=3-8, and X is phosphorus or nitrogen. The method has a tetrahedral spatial arrangement represented by:

9. The organic template has the following structure: 【Chemistry 3】 Any one or more selected from The method according to claim 8.

10. The step (1) comprises mixing a silicon source, an organic template, and water in a certain ratio under stirring until homogeneous, and obtaining a mixture of the formula: rROH:SiO ２ :wH ２ O wherein R represents a positively charged group of the organic template, and the corresponding ranges of values ​​for r and w are r=0.05-5.0 and w=1-100; The step (2) includes placing the reaction gel under an infrared lamp or in an oven to remove excess solvent, and then transferring the reaction gel to a stainless steel reaction kettle and reacting and crystallizing the reaction gel at a temperature of 80-240° C. for 1-60 days in a sealed state; 9. The method of claim 8, wherein the method further comprises the step of: (3) washing and drying the crystallized product.

11. The chemical composition of the reaction gel is represented by the formula: rROH:SiO ２ :wH ２ O The method of claim 10, wherein the corresponding value ranges of r and w are r=0.1-2.0 and w=1-30.

12. 9. The method according to claim 8, wherein the silicon source is at least one selected from the group consisting of silicic acid, silica gel, silica sol, tetraalkyl silicate, and water glass.

13. 11. The method of claim 10, wherein the crystallization conditions in step (2) comprise a crystallization temperature of 120 to 220° C. and a crystallization time of 2 to 50 days.

14. A method for synthesizing the molecular sieve of claim 4 or 5, comprising calcining the silicate material of claim 1 or 2 to remove templates in the silicate material and cause topological condensation of the framework structure, thereby obtaining a molecular sieve product.

15. The method according to claim 14, wherein the firing temperature is from 300 to 1000°C.

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