CN111547735B - Controllable synthesis method of pure silicon and high-silicon CHA molecular sieve - Google Patents
Controllable synthesis method of pure silicon and high-silicon CHA molecular sieve Download PDFInfo
- Publication number
- CN111547735B CN111547735B CN202010361283.8A CN202010361283A CN111547735B CN 111547735 B CN111547735 B CN 111547735B CN 202010361283 A CN202010361283 A CN 202010361283A CN 111547735 B CN111547735 B CN 111547735B
- Authority
- CN
- China
- Prior art keywords
- silicon
- molecular sieve
- cha molecular
- cha
- mother liquor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B39/00—Compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites; Their preparation; After-treatment, e.g. ion-exchange or dealumination
- C01B39/02—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof; Direct preparation thereof; Preparation thereof starting from a reaction mixture containing a crystalline zeolite of another type, or from preformed reactants; After-treatment thereof
- C01B39/04—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof; Direct preparation thereof; Preparation thereof starting from a reaction mixture containing a crystalline zeolite of another type, or from preformed reactants; After-treatment thereof using at least one organic template directing agent, e.g. an ionic quaternary ammonium compound or an aminated compound
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/01—Particle morphology depicted by an image
- C01P2004/03—Particle morphology depicted by an image obtained by SEM
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P30/00—Technologies relating to oil refining and petrochemical industry
- Y02P30/40—Ethylene production
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
- Inorganic Chemistry (AREA)
- Silicates, Zeolites, And Molecular Sieves (AREA)
Abstract
The invention relates to a controllable synthesis method of pure silicon and high-silicon CHA molecular sieves, which takes N, N, N-trimethyl-1-adamantyl ammonium hydroxide (TMADAOH) as a template agent, ammonium hexafluorosilicate as a silicon source or a mixture of a common silicon source and fluoride as a silicon source, and adopts the method that H, N, N-trimethyl-1-adamantyl ammonium hydroxide (TMADAOH) is subjected to ion exchange with a silicon source 2 O/SiO 2 The method has the advantages that the pure silicon and high-silicon CHA molecular sieves are efficiently and quickly synthesized in a dilute solution of about 30, the effective regulation and control of the crystal size are realized, the using amount of a template agent is reduced, the cost is reduced, and the pure silicon and high-silicon CHA molecular sieves can be efficiently and quickly synthesized at low temperature. Compared with the prior art, the CHA molecular sieve has the advantages of simple synthesis steps, good mother liquor uniformity, good molecular sieve preparation repeatability, simple particle size and distribution control, and contribution to industrial application.
Description
Technical Field
The invention relates to the field of molecular sieve synthesis, in particular to a controllable synthesis method of pure silicon and high-silicon CHA molecular sieves.
Background
Molecular sieves are a class of aluminosilicate crystalline materials having molecular scale micropores. The molecular sieve has high specific surface area and porosity, uniform micropores, adjustable acidity, unique adsorption performance, excellent stability and the like, and is widely applied to catalysis, adsorption and ion exchange processes. The small pore molecular sieves with eight membered rings mainly comprise CHA, SSZ-13, SAPO-34, DDR and LTA molecular sieves, and have wide application in the fields of catalysis, adsorption and separation. The CHA molecular sieve has a three-dimensional pore structure and lower framework density, and is superior to other molecular sieves in the aspects of adsorption and membrane separation. Although CHA molecular sieves have great potential for use in separation and catalysis, it is not straightforward to synthesize pure silicon and high silicon CHA molecular sieves.
Literature search indicates that for the synthesis of pure silicon and high silicon CHA molecular sieves (silicon to aluminum ratio greater than 100), the molecular sieves must be in H 2 O/SiO 2 A fluoride mother liquor of 3, close to dry, even H 2 O/SiO 2 At 6.5, F - /SiO 2 Ratio sum F - The/templating agent ratio is typically controlled between 1.4 and 1, respectively.
This leads to a series of problems, such as complicated mother liquor preparation process and poor uniformity, resulting in poor reproducibility of molecular sieve preparation, difficulty in controlling particle size and distribution, and the like. In the application of adsorption, membrane separation, catalysis and the like, the fine control of the size, the particle size distribution and the morphology of the molecular sieve crystal is very important.
Disclosure of Invention
The purpose of the present invention is to overcome the defects of the prior art and provide a controllable synthesis method of pure silicon and high silicon CHA molecular sieves, which has the advantages of simplified process, controllable size and shape of crystals and convenient industrialization.
The purpose of the invention can be realized by the following technical scheme:
thus, the present invention is in a conventional solution-like mother liquor (H) 2 O/SiO 2 About 30) to realize the synthesis of pure silicon and high silicon CHA molecular sieves, not only can simplify the synthesis process, but also can control the size and the morphology of CHA crystals, which is particularly important for the industrial application of the CHA molecular sieves.
Aiming at the problem, the traditional N, N, N-trimethyl-1-adamantyl ammonium hydroxide (TMADAOH) is used as a template agent, ammonium hexafluorosilicate is used as a silicon source, and H is added 2 O/SiO 2 The method has the advantages that pure silicon and high-silicon CHA molecular sieves are efficiently and rapidly synthesized in a dilute solution of about 30, the effective regulation and control of the crystal size are realized, and the dosage of a template agent is reduced.
A process for the controlled synthesis of pure silicon and high silicon CHA molecular sieves, comprising the steps of:
(1) mixing a silicon source, a template agent, alkali, water and an aluminum source, and preparing to obtain a mother solution;
(2) adding CHA molecular sieve seed crystals into the mother liquor, and aging and crystallizing to obtain the CHA molecular sieve;
(3) and roasting the CHA molecular sieve at high temperature to remove the template agent to obtain the activated CHA molecular sieve.
Further, the template agent comprises N, N-trimethyl-1-adamantyl ammonium hydroxide (TMAdaOH), the base comprises one or more of Ethylenediamine (EDA), triethylamine, dipropylamine, cyclohexylamine, or an inorganic base such as sodium hydroxide, potassium hydroxide, or ammonia, and the aluminum source comprises one or more of aluminum isopropoxide, aluminum hydroxide, or sodium metaaluminate.
Further, the silicon source comprises ammonium hexafluorosilicate, or a mixture of silica sol, silica aerosol or tetraethoxysilane with ammonium fluoride, hydrofluoric acid or other fluorides.
When ammonium hexafluorosilicate is replaced with an equimolar amount of silica sol, silica aerosol or ethyl orthosilicate, ammonium fluoride, hydrofluoric acid or other fluoride must be added to maintain the fluoride ion concentration in the mother liquor consistent with that when ammonium hexafluorosilicate is added.
Further, the silicon source comprises ammonium hexafluorosilicate, NH in mother liquor 4 SiF 6 、TMAdaOH、EDA、H 2 O and Al 2 O 3 The molar ratio of (1), (0-2), (0-8), (10-100), (0-0.01).
Preferably, NH is contained in the mother liquor 4 SiF 6 、TMAdaOH、EDA、H 2 O and Al 2 O 3 The molar ratio of (1), (0.1-0.3), (4-8), (20-30), (0-0.01).
Further, the silicon source is a mixture of silica sol, silica aerosol or tetraethoxysilane and ammonium fluoride or hydrofluoric acid, and SiO in the mother solution 2 、F - 、TMAdaOH、EDA、H 2 O and Al 2 O 3 The molar ratio of (1), (3-9), (0-2), (0-8), (10-100), (0-0.01).
Preferably, SiO in the mother liquor 2 、F - 、TMAdaOH、EDA、H 2 O and Al 2 O 3 The molar ratio of (1: 6), (0.1-0.3), (4-8), (20-30), (0-0.01).
Further, the CHA molecular sieve crystal seed is pure silicon CHA molecular sieve crystal seed with the average particle size of less than 100nm after ball milling, and the pure silicon CHA molecular sieve crystal seed after ball milling is a mixture of fragmented CHA crystals and amorphous nanoparticles.
Further, the CHA molecular sieve crystal seeds are not ball-milled and have particle sizes smaller than 300 nm.
Further, the adding amount of the CHA molecular sieve seed crystals is 0-10% of the mass of the silicon dioxide in the mother liquor.
Further, the aging time is 0.5-72 h.
Furthermore, the crystallization temperature is 348-473K, the time is 6h-15d, and the crystallization rate is fast at low temperature.
Further, the temperature of the high-temperature roasting is 370-700 ℃, and the time is 2-8 h.
Compared with the prior art, the invention has the following advantages:
(1) in the prior art, H of the synthesis mother liquor of CHA 2 O/SiO 2 Usually not more than 5, which is very low, the mother liquor is close to solid state, which brings many problems to the synthesis of molecular sieve powder, such as non-uniformity of the mother liquor, large crystal particles, wide particle size distribution, poor synthesis repeatability and other problems; in the invention, ammonium hexafluorosilicate is used as a silicon source or a common silicon source is added with corresponding fluoride, so that the solution phase synthesis of pure silicon CHA and high silicon CHA in a dilute solution is realized for the first time, small crystal grains can be obtained, and H is 2 O/SiO 2 The optimal ratio of (A) to (B) is about 30, and the excessive high and the insufficient low can form a heterogeneous phase, which is not tried by synthesizing the molecular sieve by the mother liquor close to the solid state in the prior art, thereby overcoming the technical bias existing in the prior art;
(2) in the synthesis of molecular sieve, the template agent is almost an essential component, but the price is high, which causes high cost, and a step of removing the template agent at high temperature is necessary at the later stage 2 The molar ratio of the molecular sieve is reduced to about 0.3 from 0.5-1 of the traditional concentrated solution formula, so that the molecular sieve has a great positive effect on later-stage removal and is favorable for reducing the raw material cost of the molecular sieve;
(3) in the synthesis of high silicon and all-silicon CHA molecular sieves, F - /SiO 2 Ratio sum F - The/templating agent ratio is usually controlled between 0.5-1.4 and 0.5-1, respectively, in order to avoid F - In the invention, when the common silicon source is used to replace ammonium hexafluorosilicate, fluoride is added to maintain the concentration of fluorine ions in mother liquor, F - /SiO 2 The optimal ratio is 6, which is the ratio that the synthesized molecular sieve in the prior art is not suitable for trying, and the technical bias existing in the prior art is overcome;
(4) the synthesis temperature of the high-silicon or pure-silicon CHA molecular sieve is generally higher, ammonium hexafluorosilicate is adopted as an active silicon source, the crystallization temperature is reduced to 373K, the pure-silicon CHA molecular sieve can be quickly synthesized, the crystallization rate is improved, the safety is high, and the energy consumption can be reduced to a certain degree;
(5) the seed crystal is a mixture of fragmented CHA crystals and amorphous nanoparticles, can shorten the induction period of molecular sieve synthesis, has great promotion effect on the crystallization speed of the molecular sieve, can also guide the crystallization route of the molecular sieve to obtain the same crystal phase, and is also favorable for obtaining small crystals;
(6) in conclusion, the technical scheme disclosed by the invention realizes the efficient and rapid synthesis of the all-silicon and high-silicon CHA molecular sieves in a dilute solution, realizes the effective regulation and control of the crystal size, and simultaneously reduces the dosage of the template agent and the crystallization temperature; solves a series of technical problems of complex synthesis steps of pure silicon and high-silicon CHA molecular sieves, poor mother liquor uniformity, poor repeatability of molecular sieve preparation, difficult control of particle size and distribution and the like in the prior art.
Drawings
FIG. 1 is an XRD pattern of the CHA molecular sieve prepared in comparative example 1 of the present invention;
FIG. 2 is an SEM image of the CHA molecular sieve prepared in comparative example 2 of the present invention;
FIG. 3 is an XRD pattern of CHA molecular sieves prepared in examples 1-4 of the present invention;
FIG. 4 is an SEM image of CHA molecular sieves prepared in examples 1-4 of the present invention;
FIG. 5 is an XRD pattern of the CHA molecular sieves prepared in examples 4, 6-8 of the present invention;
FIG. 6 is an SEM image of the CHA molecular sieves prepared in examples 4, 6-8 of the present invention;
FIG. 7 is an XRD pattern of the CHA molecular sieves prepared in examples 4, 9, 11-14 of the present invention;
FIG. 8 is an SEM image of CHA molecular sieves prepared in examples 4, 9, 11-14 of the present invention;
FIG. 9 is an XRD pattern of the CHA molecular sieves prepared in examples 4, 15-18 of the present invention;
FIG. 10 is an SEM image of the CHA molecular sieves prepared in examples 4, 15-18 of the present invention;
FIG. 11 is an XRD pattern of the CHA molecular sieves prepared in examples 1, 20, 21, 23 of the present invention;
FIG. 12 is an SEM image of CHA molecular sieves made according to examples 1, 20, 21, 23 of the present invention;
FIG. 13 is an XRD pattern of the CHA molecular sieve prepared in example 24 of the present invention;
FIG. 14 is an SEM image of the CHA molecular sieve prepared in example 24 of the present invention;
FIG. 15 is an XRD pattern of the CHA molecular sieve prepared in example 27 of the present invention;
FIG. 16 is an SEM image of the CHA molecular sieve prepared in example 27 of the present invention;
FIG. 17 is an XRD pattern of the CHA molecular sieve prepared in example 28 of the present invention;
FIG. 18 is an SEM image of the CHA molecular sieve prepared in example 28 of the present invention;
FIG. 19 is an XRD pattern of the CHA molecular sieves prepared in examples 4, 30 and 31 of the present invention;
FIG. 20 is an SEM image of CHA molecular sieves prepared in examples 4, 30 and 31 of the present invention;
FIG. 21 is an XRD pattern of the CHA molecular sieves prepared in examples 33-36 of the present invention;
FIG. 22 is an SEM image of CHA molecular sieves prepared in examples 33-36 of the present invention;
FIG. 23 is an XRD pattern of the CHA molecular sieves prepared in examples 37, 39 of the present invention;
FIG. 24 is an SEM image of CHA molecular sieves made in examples 37 and 39 of the present invention.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.
Various embodiments relate to a method for the controlled synthesis of pure silicon and high silicon CHA molecular sieves. Taking traditional N, N, N-trimethyl-1-adamantyl ammonium hydroxide (TMADAOH) as a template agent, ammonium hexafluorosilicate or a mixture of a common silicon source and a fluoride as a silicon source, and adding a silicon dioxide solution into the template agent 2 O/SiO 2 The method has the advantages that pure silicon and high-silicon CHA molecular sieves are efficiently and rapidly synthesized in a dilute solution of about 30, the effective regulation and control of the crystal size are realized, and the dosage of a template agent is reduced. The method specifically comprises the following steps:
(1) carrying out ball milling treatment on pure silicon CHA molecular sieve crystal seeds, and carrying out deep fragmentation and amorphization on molecular sieve crystals of CHA nano crystal seeds obtained after ball milling to obtain fine CHA molecular sieve crystals and amorphous particles, wherein the size of each of the fine CHA molecular sieve crystals and the amorphous particles is smaller than 100 nanometers and even smaller;
(2) uniformly mixing TMADAOH, EDA and deionized water, adding ammonium hexafluorosilicate, stirring for 3 hours, then adding an aluminum source (or not), and stirring overnight to obtain CHA molecular sieve mother liquor; SiO in mother liquor 2 、F - 、TMAdaOH、EDA、H 2 O and Al 2 O 3 The molar ratio of (1), (3-9), (0.01-4), (0.1-12), (10-100), (0-0.2);
(3) adding a proper amount of CHA seed crystal (0.1-50 wt%), carrying out aging treatment for 0.5-72h, and carrying out hydrothermal crystallization for 6h-15d at 348 and 473K to obtain the CHA molecular sieve;
(4) roasting at 370-700 deg.c for 2-8 hr to eliminate template agent and obtain the activated CHA molecular sieve.
The following are more detailed embodiments, and the technical solutions and the technical effects obtained by the present invention will be further described by the following embodiments.
Comparative example 1
The all-silicon CHA molecular sieve is synthesized by adopting a traditional formula, the traditional TEOS is used as a silicon source, and the formula of mother liquor is 1SiO 2 :(3-10)H 2 O0.5 TMADAOH 0.5HF, at 433K for 4 d. The XRD pattern of the prepared CHA molecular sieve is shown in figure 1. It can be seen that when H 2 O/SiO 2 When the molecular weight is less than or equal to 5, the CHA molecular sieve with pure phase can be obtained. With H 2 O/SiO 2 The improvement of (a) is that,when H is present 2 O/SiO 2 When 7, the STT phase appears. With H 2 O/SiO 2 Further improvement, the STT phase is dominant and cannot meet the requirements of the invention.
Comparative example 2
TEOS is used as silicon source, SiO in mother liquid 2 HF, trimethylamantadine hydroxide (TMADAOH) and H 2 The molar ratio of O is 1.0:0.75:0.75 (2.3-10). Crystallized at 423K for 7 days. The XRD pattern of CHA molecular sieve prepared in literature is shown in figure 2. When H is present 2 O/SiO 2 At 6, there is an STT phase present and the STT phase increases with increasing water content. The pure silicon or high-silicon CHA molecular sieve is prepared in a fluorine medium, and an STT phase appears at high temperature or high water-silicon ratio, so that the requirements of the invention cannot be met.
Example 1 this example is directed to the synthesis of an all-silicon CHA molecular sieve
A controllable synthesis method of a pure silicon CHA molecular sieve comprises the following specific steps:
step 1: mixing tetraethoxysilane and N, N, N-trimethyl-1-adamantyl ammonium hydroxide, stirring for 4 hours, then placing in an oven at 80 ℃ to remove redundant water and ethanol, then adding hydrofluoric acid, stirring to obtain seed crystal synthesis mother liquor, wherein SiO is contained in the mother liquor 2 HF, trimethylamantadine ammonium hydroxide (TMADAOH) and H 2 The molar ratio of O is 1.0:0.5:0.5: 3. Crystallizing at 453K for 48 hours to obtain pure silicon CHA molecular sieve seed crystal. The molecular sieve seed crystals were large, about 8 microns. Ball milling in a ball mill, and crushing the crystal to below 500 nm;
step 2: uniformly mixing Ethylenediamine (EDA), organic template agent N, N, N-trimethyl-1-adamantyl ammonium hydroxide (TMADAOH) and water, slowly adding silicon source ammonium hexafluorosilicate, and stirring for 3 hours to obtain the synthetic mother liquor. NH in mother liquor 4 SiF 6 TMADAOH, EDA and H 2 The molar ratio of O is 1:0.5:4: 30.
Note that: because we use two silicon sources, when the silicon source is ammonium hexafluorosilicate, the formulation needs to use NH 4 SiF 6 This chemical formula does not use SiO 2 Later, the silicon source is replaced by silica sol and fluorine ions are supplementedWhen this is the case, SiO is used in the formulation 2 。
And step 3: and (2) adding the pure silicon CHA molecular sieve seed crystal prepared in the step (1) into mother liquor, wherein the seed crystal amount is 0.5 wt% of silicon dioxide in the mother liquor, and stirring for 30 minutes.
And 4, after aging for 24 hours, putting the mother liquor into a crystallization kettle, putting the crystallization kettle in an oven for crystallization at 433K for 48 hours, cooling the crystallization kettle, filtering, washing, drying, and roasting at high temperature to obtain the CHA molecular sieve.
Example 2
The difference from example 1 is that: in step 4, crystallization was carried out at 433K for 6 hours.
Example 3
The difference from example 1 is that: in step 4, crystallization was carried out at 433K for 12 hours.
Example 4
The difference from example 1 is that: in step 4, crystallization was carried out at 433K for 24 hours.
The XRD patterns and scanning electron micrographs of the CHA molecular sieves prepared in examples 1-4 are shown in FIGS. 3-4, and Table 1 shows the effect of crystallization time. Crystallizing at 433K for 24-48h, wherein the XRD pattern is consistent with the standard CHA pattern, which shows that the invention obtains the CHA molecular sieve without impurity phase. As seen in the SEM image, crystallization at 433K for 24h gave-1.7 micron cubic CHA crystals. The crystal size can be effectively reduced in the dilute solution synthesis, the crystal size is reduced from 10-micron to 1.7 micron, and the particle size distribution is very uniform; CHA crystals appear at the beginning of crystallization for 6h under 433K, and the CHA molecular sieve with complete appearance and uniform particle size distribution is obtained as the time is prolonged to 48 h:
TABLE 1
Example 5
The difference from the embodiment 1 is that: in step 2, H of mother liquor 2 O/SiO 2 Ratio of 10, NH 4 SiF 6 TMADAOH, EDA and H 2 The molar ratio of O is 1:0.5:4: 10; in step 4, crystallization is carried out at 433K for 24 hoursThen (c) is performed.
Example 6
The difference from the embodiment 1 is that: in step 2, H of mother liquor 2 O/SiO 2 Ratio of 20, NH 4 SiF 6 TMADAOH, EDA and H 2 The molar ratio of O is 1:0.5:4: 20; in step 4, crystallization was carried out at 433K for 24 hours.
Example 7
The difference from the embodiment 1 is that: in step 2, H of mother liquor 2 O/SiO 2 Ratio of 50, NH 4 SiF 6 TMADAOH, EDA and H 2 The molar ratio of O is 1:0.5:4: 50; in step 4, crystallization was carried out at 433K for 24 hours.
Example 8
The difference from the embodiment 1 is that: in step 2, H of mother liquor 2 O/SiO 2 Ratio of 100, NH 4 SiF 6 TMADAOH, EDA and H 2 The molar ratio of O is 1:0.5:4: 100; in step 4, crystallization was carried out at 433K for 24 hours.
The XRD patterns and scanning electron micrographs of the CHA molecular sieves obtained in examples 4, 6-8 are shown in FIGS. 5-6, H 2 O/SiO 2 The effect of (c) is shown in table 2. H 2 O/SiO 2 At a ratio of 20-30, the XRD pattern was consistent with the standard CHA pattern, indicating that we obtained a heterogeneous phase-free CHA molecular sieve, which, as seen in the SEM image, yielded-1.7 micron cubic CHA crystals. The crystal size can be effectively reduced in the dilute solution synthesis, the crystal size is reduced from 10-micron to 1.7 micron, and the particle size distribution is very uniform; therefore, at H 2 O/SiO 2 The ratio is 20-30, and the CHA molecular sieve can be synthesized without impurity phase.
TABLE 2
Example 9
The difference from embodiment 1The method comprises the following steps: in step 2, the concentration of the template agent in the mother liquor is 0, NH 4 SiF 6 TMADAOH, EDA and H 2 The molar ratio of O is 1:0:4: 30; in step 4, crystallization was carried out at 433K for 24 hours.
Example 10
The difference from example 1 is that: in step 2, the concentration of the template agent in the mother liquor is 0.1, NH 4 SiF 6 TMADAOH, EDA and H 2 The molar ratio of O is 1:0.1:4: 30; in step 4, crystallization was carried out at 433K for 24 hours.
Example 11
The difference from example 1 is that: in step 2, the concentration of the template agent in the mother liquor is 0.1, NH 4 SiF 6 TMADAOH, EDA and H 2 The molar ratio of O is 1:0.1:4: 30.
Example 12
The difference from example 1 is that: in step 2, the concentration of the template agent in the mother liquor is 0.3, NH 4 SiF 6 TMADAOH, EDA and H 2 The molar ratio of O is 1:0.3:4: 30; in step 4, crystallization was carried out at 433K for 24 hours.
Example 13
The difference from example 1 is that: in step 2, the concentration of the template agent in the mother liquor is 1.0, NH 4 SiF 6 TMADAOH, EDA and H 2 The molar ratio of O is 1:1.0:4: 30; in step 4, crystallization was carried out at 433K for 24 hours.
Example 14
The difference from example 1 is that: in step 2, the concentration of the template agent in the mother liquor is 2.0, NH 4 SiF 6 TMADAOH, EDA and H 2 The molar ratio of O is 1:2.0:4: 30; in step 4, crystallization was carried out at 433K for 24 hours.
The XRD patterns and scanning electron micrographs of the CHA molecular sieves obtained in examples 4, 9, 11-14 are shown in FIGS. 7-8, TMADAOH/SiO 2 The effect of (c) is shown in table 3. When the concentration of the template agent is 0.1-2.0, the XRD pattern is consistent with the standard CHA pattern, which shows that we obtain the CHA molecular sieve without impurity phase, and when the concentration of the template agent is 0.3, the cubic CHA crystal with 0.8 micron is obtained from the SEM picture. Energy synthesis in dilute solutionThe crystal size is effectively reduced from 10-0.8 micron, and the particle size distribution is very uniform; the all-silicon CHA molecular sieve is synthesized under the condition of low template agent, so that the cost is reduced; therefore, in TMADAOH/SiO 2 The ratio is 0.1-2, and the CHA molecular sieve without impurity phase can be synthesized.
TABLE 3
Example 15
The difference from example 1 is that: in step 2, the content of ethylenediamine in the mother liquor is 0, NH 4 SiF 6 TMADAOH, EDA and H 2 The molar ratio of O is 1:0.5:0: 30. In step 4, crystallization was carried out at 433K for 24 hours.
Example 16
The difference from example 1 is that: in step 2, the content of ethylenediamine in the mother liquor is 1.2, NH 4 SiF 6 TMADAOH, EDA and H 2 The molar ratio of O is 1:0.5:1.2: 30. In step 4, crystallization was carried out at 433K for 24 hours.
Example 17
The difference from example 1 is that: in step 2, the content of ethylenediamine in the mother liquor is 2.4, NH 4 SiF 6 TMADAOH, EDA and H 2 The molar ratio of O is 1:0.5:2.4: 30. In step 4, crystallization was carried out at 433K for 24 hours.
Example 18
The difference from example 1 is that: in step 2, the content of ethylenediamine in the mother liquor is 8.0, NH 4 SiF 6 TMADAOH, EDA and H 2 The molar ratio of O is 1:0.5:8.0: 30. In step 4, crystallization was carried out at 433K for 24 hours.
The XRD patterns and scanning electron micrographs of the CHA molecular sieves obtained in examples 4, 15-18 are shown in FIGS. 9-10, EDA/SiO 2 The effect of (a) is shown in table 4. When the content of the ethylenediamine is 4.0-8.0, the XRD pattern is consistent with the standard CHA pattern, which shows that the CHA molecular sieve without impurity phase is obtained. As can be seen from the SEM image, at an ethylenediamine content of 8, a cubic shape of 1.3 μm was obtainedCHA crystals. Compared with literature data, the crystal size can be effectively reduced in the dilute solution synthesis, the crystal size is reduced from 10-micron to 1.3 micron, and the particle size distribution is very uniform; as can be seen from Table 4, when the EDA content is less than 2.4, STT hetero-phase appears, indicating insufficient basicity. Therefore, when the EDA/SiO2 ratio is 4-8, the CHA molecular sieve without impurity phase can be synthesized.
TABLE 4
Example 19
The difference from example 1 is that: in step 4, the resultant was hydrothermally synthesized at 473K for 0.25 d.
Example 20
The difference from example 1 is that: in step 4, 2d was hydrothermally synthesized at 393K, respectively.
Example 21
The difference from example 1 is that: in step 4, 2d was hydrothermally synthesized at 373K, respectively.
Example 22
The difference from example 1 is that: in step 4, the hydrothermal synthesis of 7d was carried out at 348K, respectively.
Example 23
The difference from example 1 is that: in step 4, 15d was hydrothermally synthesized at 348K, respectively.
The XRD patterns and scanning electron micrographs of the CHA molecular sieves obtained in examples 1, 20, 21 and 23 are shown in FIGS. 11-12, and the effects of crystallization temperature and time are shown in Table 5. When 2d is crystallized at 433K, 393K and 373K and 15d is crystallized at 348K, the XRD pattern is consistent with the standard CHA pattern, which shows that the invention obtains the CHA molecular sieve without impurity phase. As seen from the SEM image, the cubic CHA crystal of 1.6 microns is obtained by hydrothermal synthesis for 2d at 373K, and the size and the morphology of the obtained CHA molecular sieve crystal are not much different from those of the CHA molecular sieve crystal obtained by hydrothermal synthesis for 2d at 433K, which shows that the low-temperature crystallization rate is also very fast, and the synthesis efficiency is improved for preparing the all-silicon CHA molecular sieve. The crystal size can be effectively reduced in the dilute solution synthesis, the crystal size is reduced from 10-micron to 1.6 micron, and the particle size distribution is very uniform; therefore, the CHA molecular sieve without impurity phase can be synthesized at the hydrothermal synthesis temperature of 348K-433K.
TABLE 5
Example 24
The difference from example 1 is that: in step 2, the original ammonium hexafluorosilicate is replaced by silica sol, and then the corresponding NH is added 4 F, keeping the fluoride ion concentration in the mother liquor unchanged. SiO of mother liquor 2 、NH 4 F. TMADAOH, EDA and H 2 The molar ratio of O is 1:6:0.5:4: 30.
Example 25
The difference from example 1 is that: in step 2, the original ammonium hexafluorosilicate is replaced by silica sol, and then corresponding HF is added to maintain the concentration of fluorine ions in the mother liquor unchanged. SiO of mother liquor 2 HF, TMADAOH, EDA and H 2 The molar ratio of O is 1:6:0.5:4: 30.
Example 26
The difference from example 1 is that: in step 2, the original ammonium hexafluorosilicate is replaced by silica sol, and then corresponding KF is added to maintain the concentration of fluorine ions in the mother liquor unchanged. SiO of mother liquor 2 KF, TMADAOH, EDA and H 2 The molar ratio of O is 1:6:0.5:4: 30.
The XRD pattern and scanning electron micrograph of the CHA molecular sieve prepared in example 24 are shown in FIGS. 13-14, and the effect of the fluorine source is shown in Table 6. Addition of NH 4 At F, the XRD pattern is consistent with the standard CHA pattern, which shows that we obtain the CHA molecular sieve without impurity phase. As can be seen from the SEM image, cubic CHA crystals of 0.49 microns were obtained. The crystal size can be effectively reduced in the dilute solution synthesis, the crystal size is reduced from 10-micron to 0.49 micron, and the particle size distribution is very uniform; therefore, the mixture of the common silicon source and the fluoride with equal mol can replace ammonium hexafluorosilicate, and the pure silicon CHA molecular sieve can be obtained under the condition of high water-silicon ratio, thereby not only reducing the cost of raw materials, but also reducing the crystal size and being beneficial to application.
TABLE 6
Example 27
The difference from example 24 is that: in step 2, the original ammonium hexafluorosilicate is replaced by silica sol, and then NH with different amount is added 4 F, so as to maintain the concentration of the fluoride ions in the mother liquor. SiO of mother liquor 2 、NH 4 F. TMADAOH, EDA and H 2 The molar ratio of O is 1:3:0.5:4: 30.
Example 28
The difference from example 24 is that: in step 2, the original ammonium hexafluorosilicate is replaced by silica sol, and then NH with different amount is added 4 F, so as to maintain the concentration of the fluoride ions in the mother liquor. SiO of mother liquor 2 、NH 4 F. TMADAOH, EDA and H 2 The molar ratio of O is 1:9:0.5:4: 30.
XRD patterns and scanning electron micrographs of the CHA molecular sieves prepared in examples 27 and 28 are shown in FIGS. 15-18, NH 4 F/SiO 2 The effects of (a) are shown in Table 7. Addition of NH 4 F/SiO 2 At ratios of 3 and 9, the XRD pattern was consistent with the standard CHA pattern, indicating that we obtained a CHA molecular sieve free of impurity phases. From the SEM image, NH 4 F/SiO 2 At a ratio of 9, cubic CHA crystals of 0.62 microns were obtained. The crystal size can be effectively reduced in the dilute solution synthesis, the crystal size is reduced from 10-0.62 micron, and the particle size distribution is very uniform; therefore, the concentration of fluorine ion, NH, in the mother liquor is changed 4 F/SiO 2 When the ratio is 3-9, the pure silicon CHA molecular sieve can be obtained under the condition of high water-silicon ratio.
TABLE 7
Comparative example 3
TEOS is used as silicon source, SiO in mother liquid 2 HF, trimethylamantadine ammonium hydroxide (TMADAOH) and H 2 The molar ratio of O is 1.0 (0.5-4) to 1.4:6.5, and the hydrothermal synthesis is carried out for 7 days at 423K. When TMADAOH/SiO 2 When the content of the template agent is 0.5-0.8, STT phase appears and increases along with the decrease of the content of the template agent; TMADAOH/F is considered by those skilled in the art to be - Generally, the concentration of fluoride ions in the system is controlled to be too high to facilitate the formation of the CHA molecular sieve, but our results demonstrate that dilute solutions with high fluorine content can form the CHA molecular sieve.
Example 29
The difference from example 1 is that: step 3, adding the prepared pure silicon CHA molecular sieve seed crystal into mother liquor, wherein the seed crystal amount is 0% of the mass of silicon dioxide contained in a silicon source added into the mother liquor; in step 4, crystallization is carried out at 433K for 8 d.
Example 30
The difference from example 1 is that: step 3, adding the prepared pure silicon CHA molecular sieve seed crystal into mother liquor, wherein the seed crystal amount is 0.01 percent of the mass of silicon dioxide contained in a silicon source added into the mother liquor; in step 4, crystallization is carried out at 433K for 4 d.
Example 31
The difference from example 1 is that: step 3, adding the prepared pure silicon CHA molecular sieve seed crystal into mother liquor, wherein the seed crystal amount is 5% of the mass of silicon dioxide contained in a silicon source added into the mother liquor; in step 4, crystallization was carried out at 433K for 0.5 d.
Example 32
The difference from example 1 is that: step 3, adding the prepared pure silicon CHA molecular sieve seed crystal into mother liquor, wherein the seed crystal amount is 10% of the mass of silicon dioxide contained in a silicon source added into the mother liquor; in step 4, crystallization was carried out at 433K for 0.25 d.
The XRD patterns and scanning electron micrographs of the CHA molecular sieves prepared in examples 4, 30 and 31 are shown in FIGS. 19-20, and the effect of the seed crystals is shown in Table 8. When the amount of the crystal is 0.5 or 5 wt%, the XRD pattern is consistent with the standard CHA pattern, which indicates that we obtain the CHA molecular sieve without impurity phase. As can be seen from the SEM image, when the amount of crystal seed was 5 wt%, cubic CHA crystals of 0.8 μm were obtained. The crystal size can be effectively reduced from 10-0.8 micron by adding a large amount of crystal seeds in the dilute solution synthesis, and the particle size distribution is very uniform.
TABLE 8
Example 33
The difference from example 1 is that: in the step 3, the aging time is 0.5 h; in step 4, crystallization was carried out at 373K for 24 hours.
Example 34
The difference from example 1 is that: in the step 3, the aging time is 24 hours; in step 4, crystallization was carried out at 373K for 24 hours.
Example 35
The difference from example 1 is that: in the step 3, the aging time is 48 hours; in step 4, crystallization was carried out at 373K for 24 hours.
Example 36
The difference from example 1 is that: in the step 3, the aging time is 72 h; in step 4, crystallization was carried out at 373K for 24 hours.
The XRD patterns and scanning electron micrographs of the CHA molecular sieves prepared in examples 33-36 are shown in FIGS. 21-22, and the effect of aging time is shown in Table 9. When the aging time is 0.5-72h, the XRD pattern is consistent with the standard CHA pattern, which shows that the CHA molecular sieve without impurity phase is obtained. As can be seen from the SEM image, cubic CHA crystals of 0.9 microns were obtained at 72h aging time. The aging time can be prolonged in the dilute solution synthesis, the crystal size can be effectively reduced from 10-0.9 micron, and the particle size distribution is very uniform.
TABLE 9
Example 37 this example is directed to the synthesis of a high silicon CHA molecular sieve
The difference from example 1 is that: in step 2, adding aluminum source aluminum hydroxide into the mother liquor, and adding NH into the mother liquor 4 SiF 6 、TMAdaOH、EDA、H 2 O and Al 2 O 3 The molar ratio of (1: 0.5:4:30: 0.01); in step 4, crystallization was carried out at 433K for 24 hours.
Example 38
The difference from example 1 is that: in step 2, adding aluminum source aluminum hydroxide into the mother liquor, and adding NH into the mother liquor 4 SiF 6 、TMAdaOH、EDA、H 2 O and Al 2 O 3 The molar ratio of (1: 0.5:4:30: 0.005); in step 4, crystallization was carried out at 433K for 24 hours.
Example 39
The difference from example 1 is that: in step 2, adding aluminum source aluminum hydroxide into the mother liquor, and adding NH into the mother liquor 4 SiF 6 、TMAdaOH、EDA、H 2 O and Al 2 O 3 The molar ratio of (1: 0.5:4:30: 0.0025); in step 4, crystallization was carried out at 433K for 24 hours.
The XRD patterns and scanning electron micrographs of the CHA molecular sieves prepared in examples 37 and 39 are shown in FIGS. 23-24, and the effect of the silica to alumina ratio is shown in Table 10. SiO2 2 :Al 2 O 3 When the ratio is 1:0.01 (i.e. Si/Al is 50), the XRD pattern is consistent with the standard CHA pattern, which shows that we can obtain the CHA molecular sieve without impurity phase. As seen from the SEM image, SiO 2 :Al 2 O 3 When 1:0.01 (i.e., Si/Al of 50) and 1:0.0025 (i.e., Si/Al of 200), cubic CHA crystals of 1.4 and 1.7 μm were obtained, respectively, and Si/Al of the final product was measured by ICP-AES (inductively coupled plasma atomic emission spectroscopy) to be 48 and 189, respectively. Compared with literature data, the crystal size can be effectively reduced by adding an aluminum source in the dilute solution synthesis, the crystal size is reduced from 10-micron to 1.4 micron, and the particle size distribution is uniform; also, as can be seen from Table 9, in this system, SiO 2 :Al 2 O 3 When the molecular weight is 1 (0.01-0) (i.e., Si/Al is 50 to infinity), a high-silicon CHA molecular sieve free from a heterogeneous phase can be obtained.
In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The embodiments described above are intended to facilitate the understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.
Claims (6)
1. A process for the controlled synthesis of pure silicon and high silicon CHA molecular sieves, comprising the steps of:
(1) mixing a silicon source, a template agent, alkali, water and an aluminum source, and preparing to obtain a mother solution; the silicon source comprises ammonium hexafluorosilicate (NH) 4 ) 2 SiF 6 、TMAdaOH、EDA、H 2 O and Al 2 O 3 The molar ratio of (1) to (0.1-2) to (4-8) to (20-30) to (0-0.005);
(2) adding CHA molecular sieve seed crystals into the mother liquor, and aging and crystallizing to obtain the CHA molecular sieve; the aging time is 24-72 h; the crystallization temperature is 373-433K, and the crystallization time is 24-48 h;
(3) and roasting the CHA molecular sieve at high temperature to remove the template agent to obtain the activated CHA molecular sieve.
2. The controllable synthesis method of pure silicon and high silicon CHA molecular sieve according to claim 1, characterized in that the template agent comprises N, N, N-trimethyl-1-adamantyl ammonium hydroxide, the base comprises one or more of ethylenediamine, triethylamine, dipropylamine, cyclohexylamine, sodium hydroxide, potassium hydroxide or ammonia; the aluminum source comprises one or more of aluminum isopropoxide, aluminum hydroxide or sodium metaaluminate.
3. The controllable synthesis method of pure silicon and high-silicon CHA molecular sieve as claimed in claim 1 or 2, wherein the silicon source is silica sol, silica aerosol or mixture of tetraethoxysilane and ammonium fluoride or hydrofluoric acid, SiO in mother liquor 2 、F - 、TMAdaOH、EDA、H 2 O and Al 2 O 3 The molar ratio of (1), (3-9), (0.1-2), (4-8), (20-30), (0-0.005).
4. The controllable synthesis method of pure silicon and high-silicon CHA molecular sieve as claimed in claim 1, wherein the CHA molecular sieve seed crystal is pure silicon CHA molecular sieve seed crystal with average particle size less than 100nm after ball milling, or CHA molecular sieve seed crystal with particle size less than 300nm without ball milling.
5. The process of claim 1, wherein the amount of CHA molecular sieve seed crystals added is 0.5-10% of the mass of silica in the mother liquor.
6. The controllable synthesis method of pure silicon and high-silicon CHA molecular sieve as claimed in claim 1, wherein the high temperature calcination temperature is 370-700 ℃ for 2-8 h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010361283.8A CN111547735B (en) | 2020-04-30 | 2020-04-30 | Controllable synthesis method of pure silicon and high-silicon CHA molecular sieve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010361283.8A CN111547735B (en) | 2020-04-30 | 2020-04-30 | Controllable synthesis method of pure silicon and high-silicon CHA molecular sieve |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111547735A CN111547735A (en) | 2020-08-18 |
| CN111547735B true CN111547735B (en) | 2022-08-09 |
Family
ID=72002627
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010361283.8A Active CN111547735B (en) | 2020-04-30 | 2020-04-30 | Controllable synthesis method of pure silicon and high-silicon CHA molecular sieve |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111547735B (en) |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0795517A1 (en) * | 1996-03-13 | 1997-09-17 | Shell Internationale Researchmaatschappij B.V. | Process for the preparation of mesoporous molecular sieves and porous crystalline materials |
| JP4508654B2 (en) * | 2002-03-15 | 2010-07-21 | エクソンモービル・ケミカル・パテンツ・インク | High silica shabasite, its synthesis and its use in the conversion of oxygenates to olefins |
| US20060115398A1 (en) * | 2004-11-29 | 2006-06-01 | Chevron U.S.A. Inc. | Synthesis of amines using high-silica molecular sieve CHA |
| CN104163434B (en) * | 2014-07-18 | 2016-06-15 | 天津众智科技有限公司 | The method of crystal seed method synthesizing high-silicon aluminum ratio Chabazite-type molecular sieve and the application of molecular sieve |
| CN104925825A (en) * | 2015-06-26 | 2015-09-23 | 中国科学院上海高等研究院 | Manufacturing method of all-silicon CHA molecular sieve |
| WO2017205112A1 (en) * | 2016-05-25 | 2017-11-30 | Uop Llc | HIGH CHARGE DENSITY METALLOALUMINOPHOSPHOSILICATE MOLECULAR SIEVES MeAPSO-83 |
| CN106145138B (en) * | 2016-06-27 | 2018-05-08 | 杨晓波 | A kind of method for synthesizing the zeolite molecular sieve with chabazite structure |
| CN106629761B (en) * | 2016-12-20 | 2017-11-24 | 上海卓悦化工科技有限公司 | A kind of synthetic method of the molecular sieves of SSZ 13 |
| CN107758691B (en) * | 2017-12-12 | 2018-08-31 | 太原理工大学 | The preparation method of high silicon CHA types SSZ-13 molecular sieves |
| CN108579449B (en) * | 2018-05-14 | 2019-12-17 | 南京工业大学 | Method for rapidly synthesizing high-silicon SSZ-13 molecular sieve membrane |
| CN110407221B (en) * | 2019-06-21 | 2020-12-04 | 合肥派森新材料技术有限公司 | Preparation method of chabazite molecular sieve and preparation method of SCR catalyst |
| CN110240175A (en) * | 2019-07-16 | 2019-09-17 | 吉林大学 | A kind of method of hydro-thermal free-floride synthesis pure silicon CHA molecular sieve |
| CN111056560B (en) * | 2019-11-26 | 2023-03-31 | 上海工程技术大学 | Economic synthesis method of ultrathin SSZ-13 molecular sieve membrane |
-
2020
- 2020-04-30 CN CN202010361283.8A patent/CN111547735B/en active Active
Non-Patent Citations (3)
| Title |
|---|
| HERREROS, B等.ISOMORPHOUS REPLACEMENT OF AL BY SI IN THE FRAMEWORK OF ALPO4-5 USING (NH4)(2)SIF6.《JOURNAL OF PHYSICAL CHEMISTRY》.1995,第99卷(第23期),9514-9518. * |
| Koji Kida等.Preparation and gas permeation properties on pure silica CHA-type zeolite membranes.《Journal of Membrane Science》.2017,第522卷363-370. * |
| ZebastianBohström等.Preparation of high silica chabazite with controllable particle size.《Microporous and Mesoporous Materials》.2014,第195卷294-302. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111547735A (en) | 2020-08-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Guangyu et al. | Synthesis of SAPO-34 molecular sieves templated with diethylamine and their properties compared with other templates | |
| CN108579449B (en) | Method for rapidly synthesizing high-silicon SSZ-13 molecular sieve membrane | |
| EP2837596B1 (en) | Beta zeolite and method for producing same | |
| JP5689890B2 (en) | Method for producing ZSM-5 zeolite using nanocrystalline ZSM-5 core | |
| EP2589573B1 (en) | Zeolite production method | |
| US7824657B2 (en) | Fabrication of hierarchical zeolites | |
| US9932240B2 (en) | Method for producing zeolite crystals and/or zeolite-like crystals | |
| CN109850906B (en) | Method for preparing hierarchical pore molecular sieve with nanoparticle close-packed structure by adopting silicon dioxide nano colloidal crystal solid phase conversion method | |
| JP6418611B2 (en) | Method for producing boron-containing zeolitic material having MWW framework structure | |
| CN104986783B (en) | A method of preparing total silicon DD3R molecular sieves | |
| CN114229868B (en) | MWW molecular sieve, preparation method thereof and application of alkaloid in preparation of MWW molecular sieve | |
| CN108059170A (en) | A kind of controllable method for preparing of the ZSM-5 molecular sieve grown along c-axis | |
| CN111547735B (en) | Controllable synthesis method of pure silicon and high-silicon CHA molecular sieve | |
| CN103771451A (en) | Synthesis method for preparing pure-phase DD3R (deca-dodecasil 3rhombohedral) zeolite molecular sieve under induction of ultrafine silicon dioxide | |
| CN110407220B (en) | Rapid preparation method of SAPO-34 molecular sieve with large specific surface area | |
| EP3838843A1 (en) | Hierarchical zeolites and preparation method therefor | |
| JP2018062450A (en) | Kfi zeolite and method for producing the same | |
| Larlus et al. | Synthesis of all-silica BEA-type material in basic media | |
| CN112573536A (en) | Nano P-type zeolite, preparation method and application thereof | |
| CN111747426B (en) | Cheap synthesis method of pure silicon and high-silicon CHA molecular sieve | |
| CN112125318B (en) | Method for preparing MFI zeolite based on imidazolyl ionic liquid | |
| TW202012311A (en) | Rho zeolites and method of making the same | |
| KR20120001122A (en) | Manufacturing method of crystalline zeolite with high si-ai ratio and crystalline zeolite with high si-ai ratio prepared by using the method | |
| CN111992244A (en) | Novel methanol-to-propylene hierarchical pore ZSM-5 molecular sieve catalyst and preparation method thereof | |
| CN110980764A (en) | Modified M-SAPO-RHO type zeolite molecular sieve, and preparation method and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |