A coexistent molecular sieve of cha and mor and its preparation method and application

Abstract

The application discloses a kind of symbiotic molecular sieve of CHA and MOR and its preparation method and application.The symbiotic molecular sieve has the schematic chemical composition as shown in formula "mSiO2·nAl2O3·pR", wherein 8≤m / n≤22,100≤m / p≤500, and R is N,N,N-trimethyladamantylammonium. The preparation method of the symbiotic molecular sieve of CHA and MOR of the application is simple, and the cost is relatively low. It can be used as adsorbent or catalyst for organic compound conversion.

Description

Technical Field

[0001] This invention belongs to the field of molecular sieve technology, specifically relating to a symbiotic molecular sieve of CHA and MOR, its preparation method, and its application. Background Technology

[0002] CHA-type molecular sieves are small-pore molecular sieves consisting of AlO4 and SiO4 tetrahedra connected end-to-end by oxygen atoms, arranged in an orderly manner to form an ellipsoidal cage (0.73nm × 1.2nm) with an eight-membered ring structure and a three-dimensional intersecting pore structure with a pore size of 0.38nm × 0.38nm. Typical materials include SSZ-13 molecular sieve composed of silicon and aluminum and SAPO-34 molecular sieve composed of silicon-phosphorus-aluminum, which have the characteristics of small pore size (0.38nm), high specific surface area, good hydrothermal stability, adjustable acid center and excellent ion exchange capacity, and are used in the removal of NO from automobile exhaust. x MOR molecular sieves exhibit excellent performance in fields such as NH3-SCR, methanol conversion (MTH), and CO2 adsorption and separation, and have been widely used in numerous industrial catalytic processes in recent years. MOR-type molecular sieves possess straight channels of eight-membered and twelve-membered rings (0.67 nm × 0.70 nm) along the

[001] direction, and eight-membered rings (0.26 nm × 0.57 nm) also exist between the eight-membered and twelve-membered rings along the

[010] direction. The main channel of MOR molecular sieves is a twelve-membered ring structure, exhibiting good catalytic stability. Currently, it is widely used in processes such as hydrocracking, isomerization, alkylation, and reforming, and also for separating gas or liquid mixtures. MOR molecular sieves also show great promise for industrial applications in dimethyl ether carbonylation reactions.

[0003] Both types of molecular sieve materials suffer from problems such as uniform and uniform pore size, weak acidity, low activity, and poor selectivity, making it difficult to process complex components alone. Furthermore, their catalytic performance differs for the same reactants. Porous symbiotic molecular sieves containing two or more components, with hierarchical pore structures and a wide distribution of strong and weak acids, can process complex components with varying molecular diameters. In catalytic reactions, each component can leverage its own advantages to synergistically catalyze the processing of complex components with diverse molecular sizes.

[0004] Patent CN101514010B discloses a porous symbiotic material of mordenite / β-zeolite / aragonite and its preparation method. This method achieves the synthesis by controlling the nucleation and growth process of the molecular sieve. However, this synthesis method requires the addition of a large amount of organic structure-directing agents suitable for the growth of two or more phases, and strict control of parameters such as pH, silica-alumina ratio, and crystallization temperature of the synthesis system, making the synthesis method relatively complex. CN101279743B discloses a symbiotic molecular sieve and its synthesis method. By adding seed crystals containing β-zeolite precursors during the synthesis process, and controlling the nucleation and growth process of the molecular sieve, a symbiotic molecular sieve material of ZSM-5 / mordenite / β-zeolite is prepared. Patent CN100586858 discloses a porous symbiotic material and its synthesis method. By controlling the nucleation and growth process of molecular sieves during the synthesis of porous materials, a porous symbiotic material with an adjustable symbiotic phase ratio is prepared. This material is a ZSM-5 / mordenite / β symbiotic molecular sieve material, which can be used in the industrial production of ethylene and propylene from naphtha catalytic cracking. Patent CN104556137B discloses a MOR / ANA type porous zeolite symbiotic material and its preparation method. During the seed crystal preparation process, a quaternary ammonium salt is added, and a seed-induced overall crystallization method is used to prepare the symbiotic molecular sieve material. Patent CN106672993B discloses a MOR and ANA symbiotic zeolite and its preparation method. A bifunctional organic template agent is used as the reaction raw material, and hydrothermal crystallization yields a well-dispersed MOR and ANA symbiotic molecular sieve with a large specific surface area and pore volume, which is beneficial for applications in petrochemicals, catalysis, ion adsorption, and purification. Patents CN1296275C and CN1296276C disclose the synthesis of mixed crystal materials of β-zeolite and β-zeolite by using ZSM-5 or mordenite molecular sieve as seed crystals and adding them to the synthesis solution of mordenite zeolite or β-zeolite, respectively.

[0005] The aforementioned symbiotic zeolite molecular sieves and their preparation methods typically synthesize common symbiotic molecular sieve combinations such as MOR molecular sieves and MFI molecular sieves, or MOR molecular sieves and β molecular sieves. Currently, there are no reports of porous symbiotic molecular sieves formed from CHA and MOR type molecular sieves. Using simple methods and lower costs to prepare CHA and MOR symbiotic molecular sieves will help expand their application scenarios. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a novel eutectic molecular sieve and its preparation method not covered in the prior art, as well as its beneficial properties.

[0007] The first aspect of the present invention provides a symbiotic molecular sieve of CHA and MOR, the symbiotic molecular sieve having an illustrative chemical composition as shown in the formula "mSiO2·nAl2O3·pR", wherein 8≤m / n≤22, 100≤m / p≤500, and R is N,N,N-trimethyladamantaneammonium.

[0008] Further, the symbiotic molecular sieve includes X-ray diffraction patterns as shown in the table below, where X-ray diffraction peaks (characteristic peaks of CHA molecular sieve) appear at 2θ of 9.65±0.30°, 15.95±0.30°, 20.65±0.30°, 24.97±0.30°, and 30.86±0.30°, and characteristic peaks of MOR molecular sieve appear at 2θ of 6.31±0.30°, 9.65±0.30°, 19.41±0.30°, 25.44±0.30°, and 26.06±0.30°.

[0009]

[0010] a: ±0.30°, b: varies with 2θ.

[0011] Further, the symbiotic molecular sieve may optionally include X-ray diffraction patterns as shown in the table below, wherein X-ray diffraction peaks appear at 2θ of 12.86±0.30°, 17.75±0.30°, 22.02±0.30°, and 27.63±0.30°, which are characteristic peaks of CHA molecular sieve, and at 2θ of 8.49±0.30°, 13.62±0.30°, 15.09±0.30°, 23.45±0.30°, and 35.37±0.30°, which are characteristic peaks of MOR molecular sieve.

[0012]

[0013] a: ±0.30°, b: varies with 2θ.

[0014] A second aspect of this invention provides a method for preparing a symbiotic molecular sieve of CHA and MOR, comprising the following steps:

[0015] The symbiotic molecular sieve is prepared by mixing silicon source, aluminum source, sodium hydroxide, organic structure directing agent R and water, and crystallizing the mixture.

[0016] The silicon source is calculated as SiO2, the aluminum source as Al2O3, sodium hydroxide, the organic structure directing agent R as N,N,N-trimethyladamantane ammonium, and water, with a molar ratio of SiO2:Al2O3:NaOH:R:H2O = 1:0.04~0.13:0.18~0.32:0.002~0.025:10~50.

[0017] Furthermore, the added silicon source (SiO2), aluminum source (Al2O3), sodium hydroxide, organic structure directing agent R (N,N,N-trimethyladamantane ammonium), and water are in a molar ratio of SiO2:Al2O3:NaOH:R:H2O = 1:0.05~0.12:0.20~0.30:0.003~0.020:12~45.

[0018] Furthermore, the silicon source is silica sol; the aluminum source is sodium aluminate.

[0019] Furthermore, the sodium aluminate contains 38% to 43% Al2O3 by weight and 30% to 33% Na2O by weight.

[0020] Furthermore, the crystallization conditions of the reaction mixture are crystallization at 150–180°C for 0.5–8.0 days, preferably at 155–175°C for 1.0–7.5 days.

[0021] Furthermore, the crystallization process of the reaction mixture is a dynamic crystallization by rotation or stirring, with a rotation or stirring speed of 10 to 60 rpm.

[0022] Furthermore, the yield of the molecular sieve product exceeds 80%.

[0023] Furthermore, the crystallization can be carried out in any manner conventionally known in the art, such as by mixing the silicon source, aluminum source, sodium hydroxide, organic structure directing agent R, and water in a predetermined ratio, and then heating the resulting mixture under crystallization conditions.

[0024] Furthermore, after the crystallization step, the obtained mixture can be processed to obtain the product by any conventionally known separation method. Examples of such separation methods include filtering, washing, and drying the obtained mixture. Here, the filtration, washing, and drying can be performed in any manner conventionally known in the art. Specifically, for example, the filtration can be performed by simply vacuum filtering the obtained product mixture. For example, washing can be performed using deionized water and / or ethanol. For example, the drying temperature can be 40–250°C, preferably 60–150°C, and the drying time can be 8–30 hours, preferably 10–20 hours. This drying can be carried out under normal pressure or under reduced pressure.

[0025] Furthermore, the symbiotic molecular sieve obtained after the crystallization step can be further processed by calcination to obtain a sodium-type symbiotic molecular sieve. The calcination can be carried out in any manner conventionally known in the art, for example, the calcination temperature is generally 300–800°C, preferably 400–650°C, and the calcination time is generally 1–10 hours, preferably 3–6 hours. In addition, the calcination is generally carried out in an oxygen-containing atmosphere, such as air or an oxygen atmosphere.

[0026] Furthermore, the total specific surface area of ​​the sodium-type symbiotic molecular sieve is not less than 450 m². 2 / gram, preferably 450-800 meters 2 / gram; external specific surface area not less than 20 m² 2 / gram, preferably 20-80 meters 2 / gram; total pore volume not less than 0.30 cm³ 3 / gram, preferably 0.30 to 0.60 cm 3 / gram; and micropore volume not less than 0.18 cm³. 3 / gram, preferably 0.18 to 0.30 cm 3 / gram.

[0027] Further, the sodium-type symbiotic molecular sieve and the ammonium salt solution are ion-exchanged at a solid-liquid mass ratio of 1:5 to 1:20 at 30 to 80°C for 1 to 8 hours. After separating the solid, the ion exchange is repeated 0 to 2 times to obtain the ammonium-type symbiotic molecular sieve. Then, the ammonium-type symbiotic molecular sieve is calcined at 400 to 650°C for 1 to 10 hours to obtain the hydrogen-type symbiotic molecular sieve. The ammonium salt used for the ion exchange is selected from at least one of ammonium chloride, ammonium nitrate, ammonium carbonate, and ammonium sulfate; the concentration of ammonium ions in the ammonium salt solution is 0.1 to 1 mol / L.

[0028] Furthermore, the total acid content of the hydrogen-type symbiotic molecular sieve is not less than 1200 μmol / g, preferably 1200–2000 μmol / g; the strong acid content is not less than 400 μmol / g, preferably 400–800 μmol / g.

[0029] A third aspect of the present invention also provides a symbiotic molecular sieve composition of CHA and MOR, comprising a symbiotic molecular sieve of CHA and MOR prepared according to any of the methods described in the first aspect or according to any of the methods described in the second aspect, and a binder.

[0030] The fourth aspect of the present invention also provides the use of the symbiotic molecular sieve of CHA and MOR prepared according to any of the methods described in the first aspect, or the symbiotic molecular sieve of CHA and MOR prepared according to any of the methods described in the second aspect, or the symbiotic molecular sieve composition of CHA and MOR described in the third aspect as an adsorbent or a catalyst for the conversion of organic compounds.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] The symbiotic molecular sieve provided by this invention is a novel type of symbiotic molecular sieve, specifically a symbiotic molecular sieve with CHA and MOR structures, which has unique pore structure and physicochemical properties, enriching the types and synthesis methods of eutectic molecular sieves.

[0033] This invention uses a special aluminum source and a one-step crystallization scheme by adding a very small amount of organic structure directing agent to synthesize CHA and MOR symbiotic molecular sieves with high crystallization degree, high yield and high acid content. Attached Figure Description

[0034] Figure 1 The X-ray diffraction (XRD) pattern of the sample in Example 1;

[0035] Figure 2 The X-ray diffraction (XRD) pattern of the sample in Example 2;

[0036] Figure 3 The X-ray diffraction (XRD) pattern of the sample in Example 3;

[0037] Figure 4 The X-ray diffraction (XRD) pattern of the sample in Example 4;

[0038] Figure 5 The X-ray diffraction (XRD) pattern of the sample in Example 5;

[0039] Figure 6 The X-ray diffraction (XRD) pattern of the sample in Example 6;

[0040] Figure 7 The X-ray diffraction (XRD) pattern of the sample in Example 7;

[0041] Figure 8 The X-ray diffraction (XRD) pattern of the sample in Example 8;

[0042] Figure 9 The X-ray diffraction (XRD) pattern of the sample in Example 9;

[0043] Figure 10 The X-ray diffraction (XRD) pattern of the sample in Example 10;

[0044] Figure 11 The X-ray diffraction (XRD) pattern of the sample in Comparative Example 1 is shown.

[0045] Figure 12 The image shows the X-ray diffraction (XRD) pattern of the sample in Comparative Example 2. Detailed Implementation

[0046] In the context of this specification, the structures of CHA and MOR molecular sieves are 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 samples is observed using a scanning electron microscope (SEM) to confirm that the samples contain only one type of crystal, i.e., the molecular sieve samples are pure phases. XRD testing is then performed to ensure that there are no interfering peaks from other crystals in the diffraction patterns of the XRD patterns.

[0047] In the context of this specification, in the XRD data of molecular sieves, w, m, s, and vs represent diffraction peak intensities, with w being weak, m being moderate, s being strong, and vs being very strong, as is well known to those skilled in the art. Generally, w is less than 20; m is 20–40; s is 40–70; and vs is greater than 70.

[0048] In the context of this specification, including in the following examples and comparative examples, the X-ray powder diffractometer used for the molecular sieves is a Panalytical X-PERPRO 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.

[0049] In the context of this specification, including in the following examples and comparative examples, the micropore size, pore volume, specific surface area, and external specific surface area of ​​the molecular sieve were measured by the nitrogen physical adsorption-desorption method (BET method): the nitrogen physical adsorption-desorption isotherm of the molecular sieve was measured using a Micromeretic ASAP2020M physical adsorption instrument, and then calculated using the BET equation and t-plot equation. The experimental conditions for this molecular sieve were: measurement temperature -196℃, and before measurement, the molecular sieve was heat-treated at 550℃ in air for 6 hours, followed by pretreatment in vacuum at 350℃ for 4 hours.

[0050] In the context of this specification, including in the following examples and comparative examples, the content of each element in the molecular sieve was determined by inductively coupled plasma atomic emission spectrometry (ICP) using a Varian 725-ES instrument. The analytical sample was dissolved in hydrofluoric acid before testing, and the content was expressed in moles.

[0051] In the context of this specification, including the following examples and comparative examples, the acid content of the molecular sieves was determined using an Altamira AMI-3300 instrument with NH3-TPD chemisorption-desorption curves. Before testing, the samples were activated at 550°C for 1 hour, ammonia was adsorbed at 100°C for 20 minutes, and then desorbed and detected at 100–600°C. By analyzing the Gaussian peak distribution, the acid content corresponding to desorption temperatures above 300°C was considered the acid content of strong acids.

[0052] In the context of this specification, including in the following examples and comparative examples, the yield of molecular sieves refers to the percentage of the mass of the calcined sample relative to the sum of the masses of SiO2 and Al2O3 contained in the raw material.

[0053] In the context of this specification, including in the following examples and comparative examples, the organic content in the molecular sieves was determined by thermogravimetric analysis (TGA) using an SDT Q600 V20.9 Build 20 instrument. 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 within the range of 200–700°C was taken as the organic content of the sample.

[0054] The present invention will be further described in detail below with reference to the embodiments, but the present invention is not limited to these embodiments.

[0055] Example 1

[0056] A mixture was prepared by stirring 19.68 g of deionized water, 2.145 g of sodium aluminate (containing 40.5 wt% Al₂O₃ and 30.6 wt% Na₂O), 0.020 g of sodium hydroxide, 0.36 g of N,N,N-trimethyladamantane ammonium solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium) (organic structure directing agent R), and 12.80 g of silica sol (containing 40.0 wt% SiO₂) at room temperature for 2 hours. The final material ratio (molar ratio) was:

[0057] SiO2 / Al2O3 = 10;

[0058] NaOH / SiO2 = 0.24;

[0059] N,N,N-Trimethyladamantaneammonium / SiO2 = 0.005;

[0060] H2O / SiO2 = 18.

[0061] The mixture was placed in a stainless steel reactor and heated to crystallize at 160°C with a stirring speed of 20 rpm for 3 days. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product is shown below. Figure 1 As shown in Table 1, these are molecular sieves with CHA and MOR structures coexisting.

[0062] Table 1

[0063]

[0064]

[0065] The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 10.2 using inductively coupled plasma atomic emission spectrometry (ICP). The chemical composition of the sample was "1SiO2·0.098Al2O3·0.003R". After calcining the sample in air at 550℃ for 6 hours, the yield of the molecular sieve was 87 wt%, and the specific surface area of ​​the molecular sieve was 688 m². 2 / gram, with an external specific surface area of ​​45 m² measured by the BET method. 2 / g; Total pore volume 0.45cm 3 / gram, micropore volume is 0.20 cm³ 3 / g. Sodium-type molecular sieves were subjected to ammonium ion exchange with 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 65℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain hydrogen-type symbiotic molecular sieve samples. NH3-TPD analysis showed that the total acid content of the molecular sieve was 1867 μmol / g, and the strong acid content was 578 μmol / g.

[0066] Example 2

[0067] A mixture was prepared by stirring 33.59 g of deionized water, 1.733 g of sodium aluminate (containing 42.5 wt% Al2O3 and 30.6 wt% Na2O), 0.263 g of sodium hydroxide, 0.76 g of N,N,N-trimethyladamantane ammonium solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium) (organic structure directing agent R), and 13.56 g of silica sol (containing 40.0 wt% SiO2) at room temperature for 2 hours. The final material ratio (molar ratio) was:

[0068] SiO2 / Al2O3 = 12.5;

[0069] NaOH / SiO2 = 0.26;

[0070] N,N,N-trimethyladamantane ammonium / SiO2 = 0.010;

[0071] H2O / SiO2 = 26.

[0072] The mixture was placed in a stainless steel reactor and heated to crystallize at 155°C with a stirring speed of 30 rpm for 7 days. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product is shown below. Figure 2 As shown in Table 2, these are molecular sieves with CHA and MOR structures coexisting.

[0073] Table 2

[0074]

[0075]

[0076] The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 12.3 using inductively coupled plasma atomic emission spectrometry (ICP). The chemical composition of the sample was "1SiO2·0.081Al2O3·0.005R". After calcining the sample in air at 550℃ for 6 hours, the yield of the molecular sieve was 86 wt%, and the specific surface area of ​​the molecular sieve was 674 m². 2 / gram, with an external specific surface area of ​​36 m² measured by the BET method. 2 / g; Total pore volume 0.45cm 3 / gram, micropore volume is 0.19 cm³ 3 / g. Sodium-type molecular sieves were subjected to ammonium ion exchange with 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 65℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain hydrogen-type symbiotic molecular sieve samples. NH3-TPD analysis showed that the total acid content of the molecular sieve was 1752 μmol / g, and the strong acid content was 551 μmol / g.

[0077] Example 3

[0078] A mixture was prepared by stirring 46.65 g of deionized water, 1.653 g of sodium aluminate (containing 40.5 wt% Al₂O₃ and 33 wt% Na₂O), 0.204 g of sodium hydroxide, 1.66 g of N,N,N-trimethyladamantane ammonium solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium) (organic structure directing agent R), and 14.79 g of silica sol (containing 40.0 wt% SiO₂) at room temperature for 2 hours. The final material ratio (molar ratio) was:

[0079] SiO2 / Al2O3 = 15;

[0080] NaOH / SiO2 = 0.22;

[0081] N,N,N-Trimethyladamantaneammonium / SiO2 = 0.020;

[0082] H2O / SiO2 = 32.

[0083] The mixture was placed in a stainless steel reactor and heated to crystallize at 165°C with a stirring speed of 40 rpm for 5.5 days. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product is shown below. Figure 3 As shown in Table 3, these are molecular sieves with CHA and MOR structures coexisting.

[0084] Table 3

[0085]

[0086] The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 15.2 using inductively coupled plasma atomic emission spectrometry (ICP). The chemical composition of the sample was "1SiO2·0.066Al2O3·0.010R". After calcining the sample in air at 550℃ for 6 hours, the yield of the molecular sieve was 90 wt%, and the specific surface area of ​​the molecular sieve was 656 m². 2 / gram, with an external specific surface area of ​​59 m² measured by the BET method. 2 / g; Total pore volume 0.39cm 3 / gram, micropore volume is 0.21 cm³ 3 / g. Sodium-type molecular sieves were subjected to ammonium ion exchange with 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 65℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain hydrogen-type symbiotic molecular sieve samples. NH3-TPD analysis showed that the total acid content of the molecular sieve was 1640 μmol / g, and the strong acid content was 506 μmol / g.

[0087] Example 4

[0088] A mixture was prepared by stirring 53.62 g of deionized water, 1.154 g of sodium aluminate (containing 40.5 wt% Al2O3 and 30.6 wt% Na2O), 0.304 g of sodium hydroxide, 1.16 g of N,N,N-trimethyladamantane ammonium solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium) (organic structure directing agent R), and 13.77 g of silica sol (containing 40.0 wt% SiO2) at room temperature for 2 hours. The final material ratio (molar ratio) was:

[0089] SiO2 / Al2O3 = 20;

[0090] NaOH / SiO2 = 0.20;

[0091] N,N,N-trimethyladamantane ammonium / SiO2 = 0.015;

[0092] H2O / SiO2 = 38.

[0093] The mixture was placed in a stainless steel reactor and heated to crystallize at 170°C with a stirring speed of 10 rpm for 3 days. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product is shown below. Figure 4 As shown in Table 4, these are molecular sieves with CHA and MOR structures coexisting.

[0094] Table 4

[0095]

[0096]

[0097] The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 19.8 using inductively coupled plasma atomic emission spectrometry (ICP). The chemical composition of the sample was "1SiO2·0.050Al2O3·0.008R". After calcining the sample in air at 550℃ for 6 hours, the yield of the molecular sieve was 88 wt%, and the specific surface area of ​​the molecular sieve was 702 m². 2 / gram, with an external specific surface area of ​​49 m² measured by the BET method. 2 / g; Total pore volume 0.45cm 3 / gram, micropore volume is 0.24 cm³ 3 / g. Sodium-type molecular sieves were subjected to ammonium ion exchange with 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 65℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain hydrogen-type symbiotic molecular sieve samples. NH3-TPD analysis showed that the total acid content of the molecular sieve was 1254 μmol / g, and the strong acid content was 458 μmol / g.

[0098] Example 5

[0099] A mixture was prepared by stirring 10.95 g of deionized water, 2.399 g of sodium aluminate (containing 38.5 wt% Al2O3 and 30.6 wt% Na2O), 0.014 g of sodium hydroxide, 0.19 g of N,N,N-trimethyladamantane ammonium solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium) (organic structure directing agent R), and 11.56 g of silica sol (containing 40.0 wt% SiO2) at room temperature for 2 hours. The final material ratio (molar ratio) was:

[0100] SiO2 / Al2O3 = 8.5;

[0101] NaOH / SiO2 = 0.28;

[0102] N,N,N-trimethyladamantane ammonium / SiO2 = 0.003;

[0103] H2O / SiO2 = 13.

[0104] The mixture was placed in a stainless steel reactor and heated to crystallize at 175°C with a stirring speed of 60 rpm for 2 days. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product is shown below. Figure 5 As shown in Table 5, these are molecular sieves with CHA and MOR structures coexisting.

[0105] Table 5

[0106]

[0107]

[0108] The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 8.7 using inductively coupled plasma atomic emission spectrometry (ICP). The chemical composition of the sample was "1SiO2·0.115Al2O3·0.002R". After calcining the sample in air at 550℃ for 6 hours, the yield of the molecular sieve was 86 wt%, and the specific surface area of ​​the molecular sieve was 643 m². 2 / gram, with an external specific surface area of ​​53 m² measured by the BET method. 2 / g; Total pore volume 0.52cm 3 / gram, micropore volume is 0.22 cm³ 3 / g. Sodium-type molecular sieves were subjected to ammonium ion exchange with 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 65℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain hydrogen-type symbiotic molecular sieve samples. NH3-TPD analysis showed that the total acid content of the molecular sieve was 1958 μmol / g, and the strong acid content was 569 μmol / g.

[0109] Example 6

[0110] A mixture was prepared by stirring 15.41 g of deionized water, 2.010 g of sodium aluminate (containing 40.5 wt% Al2O3 and 30.6 wt% Na2O), 0.051 g of sodium hydroxide, 0.54 g of N,N,N-trimethyladamantane ammonium solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium) (organic structure directing agent R), and 11.99 g of silica sol (containing 40.0 wt% SiO2) at room temperature for 2 hours. The final material ratio (molar ratio) was:

[0111] SiO2 / Al2O3 = 10;

[0112] NaOH / SiO2 = 0.25;

[0113] N,N,N-Trimethyladamantaneammonium / SiO2 = 0.008;

[0114] H2O / SiO2 = 16.

[0115] The mixture was placed in a stainless steel reactor and heated to crystallize at 165°C with a stirring speed of 30 rpm for 3.5 days. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product is shown below. Figure 6 As shown in Table 6, these are molecular sieves with CHA and MOR structures coexisting.

[0116] Table 6

[0117]

[0118] The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 10.3 using inductively coupled plasma atomic emission spectrometry (ICP). The chemical composition of the sample was "1SiO2·0.097Al2O3·0.004R". After calcining the sample in air at 550℃ for 6 hours, the yield of the molecular sieve was 89 wt%, and the specific surface area of ​​the molecular sieve was 629 m². 2 / gram, with an external specific surface area of ​​39 m² measured by the BET method. 2 / g; Total pore volume 0.35cm 3 / gram, micropore volume is 0.19 cm³ 3 / g. Sodium-type molecular sieves were subjected to ammonium ion exchange with 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 65℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain hydrogen-type symbiotic molecular sieve samples. NH3-TPD analysis showed that the total acid content of the molecular sieve was 1849 μmol / g, and the strong acid content was 554 μmol / g.

[0119] Example 7

[0120] A mixture was prepared by stirring 25.01 g of deionized water, 1.318 g of sodium aluminate (containing 40.5 wt% Al2O3 and 30.6 wt% Na2O), 0.247 g of sodium hydroxide, 0.85 g of N,N,N-trimethyladamantane ammonium solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium) (organic structure directing agent R), and 12.58 g of silica sol (containing 40.0 wt% SiO2) at room temperature for 2 hours. The final material ratio (molar ratio) was:

[0121] SiO2 / Al2O3 = 16;

[0122] NaOH / SiO2 = 0.22;

[0123] N,N,N-trimethyladamantane ammonium / SiO2 = 0.012;

[0124] H2O / SiO2 = 22.

[0125] The mixture was placed in a stainless steel reactor and heated at 160°C with a stirring speed of 10 rpm for 5 days to crystallize. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product is shown below. Figure 7 As shown in Table 7, these are molecular sieves with CHA and MOR structures coexisting.

[0126] Table 7

[0127]

[0128] The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 16.2 using inductively coupled plasma atomic emission spectrometry (ICP). The chemical composition of the sample was "1SiO2·0.061Al2O3·0.005R". After calcining the sample in air at 550℃ for 6 hours, the yield of the molecular sieve was 90 wt%, and the specific surface area of ​​the molecular sieve was 608 m². 2 / gram, with an external specific surface area of ​​66 m² measured by the BET method. 2 / g; Total pore volume 0.52cm 3 / gram, micropore volume is 0.20 cm³ 3 / g. Sodium-type molecular sieves were subjected to ammonium ion exchange with 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 65℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain hydrogen-type symbiotic molecular sieve samples. NH3-TPD analysis showed that the total acid content of the molecular sieve was 1494 μmol / g, and the strong acid content was 482 μmol / g.

[0129] Example 8

[0130] A mixture was prepared by stirring 46.10 g of deionized water, 1.465 g of sodium aluminate (containing 40.5 wt% Al₂O₃ and 30.6 wt% Na₂O), 0.293 g of sodium hydroxide, 1.41 g of N,N,N-trimethyladamantane ammonium solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium) (organic structure directing agent R), and 15.73 g of silica sol (containing 40.0 wt% SiO₂) at room temperature for 2 hours. The final material ratio (molar ratio) was:

[0131] SiO2 / Al2O3 = 18;

[0132] NaOH / SiO2 = 0.20;

[0133] N,N,N-trimethyladamantane ammonium / SiO2 = 0.016;

[0134] H2O / SiO2 = 30.

[0135] The mixture was placed in a stainless steel reactor and heated to crystallize at 170°C with a stirring speed of 20 rpm for 4 days. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product is shown below. Figure 8 As shown in Table 8, these are molecular sieves with CHA and MOR structures coexisting.

[0136] Table 8

[0137]

[0138]

[0139] The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 18.1 using inductively coupled plasma atomic emission spectrometry (ICP). The chemical composition of the sample was "1SiO2·0.055Al2O3·0.006R". After calcining the sample in air at 550℃ for 6 hours, the yield of the molecular sieve was 88 wt%, and the specific surface area of ​​the molecular sieve was 587 m². 2 / gram, with an external specific surface area of ​​58 m² measured by the BET method. 2 / g; Total pore volume 0.56cm 3 / gram, micropore volume is 0.21 cm³ 3 / g. Sodium-type molecular sieves were subjected to ammonium ion exchange with 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 65℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain hydrogen-type symbiotic molecular sieve samples. NH3-TPD analysis showed that the total acid content of the molecular sieve was 1379 μmol / g, and the strong acid content was 476 μmol / g.

[0140] Example 9

[0141] A mixture was prepared by stirring 41.09 g of deionized water, 1.711 g of sodium aluminate (containing 40.5 wt% Al₂O₃ and 30.6 wt% Na₂O), 0.342 g of sodium hydroxide, 1.54 g of N,N,N-trimethyladamantane ammonium solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium) (organic structure directing agent R), and 15.31 g of silica sol (containing 40.0 wt% SiO₂) at room temperature for 2 hours. The final material ratio (molar ratio) was:

[0142] SiO2 / Al2O3 = 15;

[0143] NaOH / SiO2 = 0.24;

[0144] N,N,N-trimethyladamantane ammonium / SiO2 = 0.018;

[0145] H2O / SiO2 = 28.

[0146] The mixture was placed in a stainless steel reactor and heated to crystallize at 155°C with a stirring speed of 15 rpm for 6.5 days. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product is shown below. Figure 9 As shown in Table 9, these are molecular sieves with CHA and MOR structures coexisting.

[0147] Table 9

[0148]

[0149]

[0150] The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 14.9 using inductively coupled plasma atomic emission spectrometry (ICP). The chemical composition of the sample was "1SiO2·0.067Al2O3·0.008R". After calcining the sample in air at 550℃ for 6 hours, the yield of the molecular sieve was 87 wt%, and the specific surface area of ​​the molecular sieve was 649 m². 2 / gram, with an external specific surface area of ​​32 m² measured by the BET method. 2 / g; Total pore volume 0.46cm 3 / gram, micropore volume is 0.19 cm³ 3 / g. Sodium-type molecular sieves were subjected to ammonium ion exchange with 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 65℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain hydrogen-type symbiotic molecular sieve samples. NH3-TPD analysis showed that the total acid content of the molecular sieve was 1663 μmol / g, and the strong acid content was 522 μmol / g.

[0151] Example 10

[0152] A mixture was prepared by stirring 9.55 g of deionized water, 0.718 g of sodium aluminate (containing 40.5 wt% Al₂O₃ and 30.6 wt% Na₂O), 0.212 g of sodium hydroxide, 0.96 g of N,N,N-trimethyladamantane ammonium solution (containing 25.12 wt% N,N,N-trimethyladamantane ammonium) (organic structure directing agent R), and 8.56 g of silica sol (containing 40.0 wt% SiO₂) at room temperature for 2 hours. The final material ratio (molar ratio) was:

[0153] SiO2 / Al2O3 = 20;

[0154] NaOH / SiO2 = 0.21;

[0155] N,N,N-Trimethyladamantaneammonium / SiO2 = 0.02;

[0156] H2O / SiO2 = 15.

[0157] The mixture was placed in a stainless steel reactor and heated to crystallize at 170°C with a stirring speed of 50 rpm for 1.5 days. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product is shown below. Figure 10 As shown in Table 10, these are molecular sieves with CHA and MOR structures coexisting.

[0158] Table 10

[0159]

[0160] The SiO2 / Al2O3 molar ratio of the molecular sieve was determined to be 19.8 using inductively coupled plasma atomic emission spectrometry (ICP). The chemical composition of the sample was "1SiO2·0.051Al2O3·0.009R". After calcining the sample in air at 550℃ for 6 hours, the yield of the molecular sieve was 86 wt%, and the specific surface area of ​​the molecular sieve was 693 m². 2 / gram, with an external specific surface area of ​​36 m² measured by the BET method. 2 / g; Total pore volume 0.41cm 3 / gram, micropore volume is 0.23 cm³ 3 / g. Sodium-type molecular sieves were subjected to ammonium ion exchange with 0.2 mol / L NH4NO3 solution (mass ratio 1:20) at 65℃ for 2 hours, followed by centrifugation and washing. The ammonium ion exchange was repeated twice. The resulting sample was dried overnight at 100℃ and calcined in air at 550℃ for 6 hours to obtain hydrogen-type symbiotic molecular sieve samples. NH3-TPD analysis showed that the total acid content of the molecular sieve was 1226 μmol / g, and the strong acid content was 469 μmol / g.

[0161] Comparative Example 1

[0162] The material ratio is the same as in Example 1, except that less aluminum source is added. The final material ratio (molar ratio) is:

[0163] SiO2 / Al2O3 = 45;

[0164] NaOH / SiO2 = 0.24;

[0165] N,N,N-Trimethyladamantaneammonium / SiO2 = 0.005;

[0166] H2O / SiO2 = 18.

[0167] The mixture was placed in a stainless steel reactor and heated to crystallize at 160°C with a stirring speed of 20 rpm for 3 days. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product is shown below. Figure 11 As shown, the sample is uncrystallized, is amorphous, and is not a molecular sieve with a symbiotic structure of CHA and MOR.

[0168] Comparative Example 2

[0169] The material ratio is the same as in Example 1, except that the added sodium aluminate contains different contents of Al2O3 and Na2O (containing 50.6% by weight of Al2O3 and 45.2% by weight of Na2O). The raw materials are prepared according to the same amount of substances.

[0170] The mixture was placed in a stainless steel reactor and heated to crystallize at 160°C with a stirring speed of 20 rpm for 3 days. After crystallization, the mixture was filtered, washed, and dried overnight in an oven at 100°C. The XRD pattern of the obtained product is shown below. Figure 12 As shown, the sample has a pure-phase MOR structure, does not contain a CHA structure, and is not a symbiotic molecular sieve of CHA and MOR.

[0171] The specific 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 combining the 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. A symbiotic molecular sieve of CHA and MOR, having a schematic chemical composition as shown in formula "mSiO 2 •nAl 2 O 3 •pR", wherein 8≤m / n≤22, 100≤m / p≤500, and R is N, N, N-trimethyladamantammonium.

2. The intergrown molecular sieve of claim 1, wherein The symbiotic molecular sieve comprises an X-ray diffraction pattern as shown in the following table, wherein X-ray diffraction peaks appear at 2θ of 9.65±0.30°, 15.95±0.30°, 20.65±0.30°, 24.97±0.30°, 30.86±0.30°, which are characteristic peaks of CHA molecular sieve, and X-ray diffraction peaks appear at 2θ of 6.31±0.30°, 9.65±0.30°, 19.41±0.30°, 25.44±0.30°, 26.06±0.30°, which are characteristic peaks of MOR molecular sieve: a: ±0.30°, b: varies with 2θ.

3. The intergrown molecular sieve of claim 1, wherein The symbiotic molecular sieve optionally comprises an X-ray diffraction pattern as shown in the following table, wherein X-ray diffraction peaks appear at 2θ of 12.86±0.30°, 17.75±0.30°, 22.02±0.30° and 27.63±0.30°, which are characteristic peaks of CHA molecular sieve, and X-ray diffraction peaks appear at 2θ of 8.49±0.30°, 13.62±0.30°, 15.09±0.30°, 23.45±0.30° and 35.37±0.30°, which are characteristic peaks of MOR molecular sieve: a: ±0.30°, b: varies with 2θ. 4.A method for preparing a symbiotic molecular sieve of CHA and MOR, comprising the following steps: mixing a silicon source, an aluminum source, sodium hydroxide, an organic structure directing agent R and water, and crystallizing to obtain the symbiotic molecular sieve; wherein The silicon source in terms of SiO 2, the aluminum source in terms of Al 2 O 3, sodium hydroxide, the organic structure directing agent R in terms of N, N, N-trimethyladamantammonium and water are mixed in a molar ratio of SiO 2 :Al 2 O 3 :NaOH:R:H 2 O=1:0.04~0.13:0.18~0.32:0.002~0.025:10~50.

5. The method for preparing a symbiotic molecular sieve according to claim 4, characterized by, The silicon source in terms of SiO 2, the aluminum source in terms of Al 2 O 3, sodium hydroxide, the organic structure directing agent R in terms of N, N, N-trimethyladamantammonium and water are mixed in a molar ratio of SiO 2 :Al 2 O 3 :NaOH:R:H 2 O=1:0.05~0.12:0.20~0.30:0.003~0.020:12~45.

6. The method for preparing a symbiotic molecular sieve according to claim 4, characterized by, The silicon source is silica sol; and the aluminum source is sodium aluminate.

7. The method for preparing a symbiotic molecular sieve according to claim 6, characterized by, The content of Al 2 O 3 in the sodium aluminate is 38%~43% by weight, and the content of Na 2 O is 30%~33% by weight.

8. The method for preparing a symbiotic molecular sieve according to claim 4, characterized by, The crystallization condition of the reaction mixture is 150~180℃ for 0.5~8.0 days.

9. The method for preparing a symbiotic molecular sieve according to claim 8, characterized by, The crystallization condition of the reaction mixture is 155~175℃ for 1.0~7.5 days.

10. The method for preparing a symbiotic molecular sieve according to claim 4, characterized by, The crystallization process of the reaction mixture is dynamic crystallization by rotation or stirring, and the rotation or stirring speed is 10~60rpm.

11. The intergrown molecular sieve of any one of claims 1 to 3 or prepared by the method of any one of claims 4 to 10, wherein, calcining at 300-800℃ for 1-10 hours to obtain the sodium-type intergrowth molecular sieve: The total specific surface area of the sodium-type paragenetic molecular sieve is not less than 450 meters 2 / gram; and / or, The sodium-type paragenetic molecular sieve has an external specific surface area of not less than 20 m2 / g 2 / gram; and / or, The total pore volume of the sodium-type paragenetic molecular sieve is not less than 0.30 cm3 / g 3 / gram; and / or, The micropore volume of the sodium-type paragenetic molecular sieve is not less than 0.18 cm3 / g 3 / gram.

12. The symbiotic molecular sieve of claim 11 wherein, calcining at 400-650℃ for 3-6 hours to obtain the sodium-type intergrowth molecular sieve: The total specific surface area of the sodium-type paragenetic molecular sieve is 450-800 m2 / g 2 / gram; and / or, The sodium-type paragenetic molecular sieve has an external specific surface area of 20-80 m2 / g 2 / gram; and / or, The sodium-type coexisting molecular sieve has a total pore volume of 0.30-0.60 cm3 / g 3 / gram; and / or, The micropore volume of the sodium-type paragenetic molecular sieve is 0.18-0.30 cm3 / g 3 / gram.

13. The symbiotic molecular sieve of claim 12 wherein, after being treated by ammonium ion exchange to be hydrogen type: the total acid amount of the hydrogen-type intergrowth molecular sieve is not less than 1200μmol / g; and / or, the strong acid amount of the hydrogen-type intergrowth molecular sieve is not less than 400μmol / g.

14. The symbiotic molecular sieve of claim 13 wherein, after being treated by ammonium ion exchange to be hydrogen type: the total acid amount of the hydrogen-type intergrowth molecular sieve is 1200-2000μmol / g; and / or, the strong acid amount of the hydrogen-type intergrowth molecular sieve is 400-800μmol / g.

15. A CHA and MOR intergrowth molecular sieve composition comprising the CHA and MOR intergrowth molecular sieve according to any one of claims 1-3 or prepared according to any one of claims 4-10, and a binder.

16. Use of the intergrowth molecular sieve according to any one of claims 1-3 or prepared according to any one of claims 4-10 as an adsorbent or a catalyst for organic compound conversion.

17. Use of the intergrowth molecular sieve composition according to claim 15 as an adsorbent or a catalyst for organic compound conversion.

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