CN107758685B - Nano aggregated sheet mordenite - Google Patents
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- CN107758685B CN107758685B CN201610707697.5A CN201610707697A CN107758685B CN 107758685 B CN107758685 B CN 107758685B CN 201610707697 A CN201610707697 A CN 201610707697A CN 107758685 B CN107758685 B CN 107758685B
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Abstract
The invention relates to synthesis of nano aggregated sheet mordenite, which mainly aims to overcome the defects of low diffusion speed and unsmooth diffusion channel in practical application due to high surface energy of a conventional nano molecular sieve in the synthesis process, which is easy for a plurality of nano crystal clusters to form spherical and other blocky aggregates, thereby seriously affecting the reaction performance of the nano molecular sieve and the stability of the nano molecular sieve. According to the method, a small amount of oxygen-containing organic solvent is added, and the structure guide effect of tetraethylammonium cation of an organic template agent is matched, so that the nano-aggregation sheet-shaped mordenite can be efficiently synthesized, and the composition and the dissociation balance of silicon-aluminum gel are controlled by the concentration of tetraethylammonium in a synthesis system.
Description
Technical Field
The invention relates to a nano aggregated sheet mordenite.
Background
Mordenite, one of the earliest zeolites recognized by human beings, is a crystalline aluminosilicate with special acid distribution and regular mass transfer pore channels, and has important industrial application value in the petrochemical fields of adsorption separation, catalytic cracking, disproportionated transalkylation, isomerization and the like as an efficient solid acid catalyst. The mordenite crystals have strong c-axis growth potential energy, so that the pore channels of the mordenite crystals are too long along the 12MR direction, and the mass transfer diffusion efficiency of the mordenite crystals is seriously influenced. Reducing the size of the molecular sieve to nanoscale is a method for effectively improving the external specific surface area of the molecular sieve and improving the mass transfer rate, and the advantages of the nanoscale molecular sieve compared with the micron-sized molecular sieve are as follows: (1) the specific surface area is large, the number of active centers is large, the surface energy is high, unsaturated bonds on the outer surface are active, molecules are easy to adsorb, and meanwhile, the composition has high component dispersibility and loading capacity on loaded metals; (2) has short and regular pore channels and more uniform space distribution of skeleton constituent elements, and accelerates mass transfer of reactant and product molecules. The method is very beneficial to the reaction limited by diffusion, and the service life of the catalyst is prolonged; (3) the significant increase in the amount of acid on the external surface resulting from nanocrystallization may alter the selectivity of the molecular sieve, being present on the external surface in the form of "half" supercages (half cages).
The composition of a dispersion medium is one of key factors influencing the synthesis of the nano zeolite, and researches of Sun Winner and the like find that alkoxy of alcohol can replace non-framework bridge hydroxyl on the surface of a micelle, the electrostatic repulsive force between polar surfaces of particles is increased due to higher dielectric constant, so that the agglomeration tendency is reduced, the dispersibility is improved, the solubility of silicon-aluminum gel is improved due to the alcoholic hydroxyl, the crystallization kinetic process is further influenced, crystals preferentially grow along a certain axial direction, the potential plane is narrowed, and defects are generated on the corresponding potential plane, isopropanol or ethanol is added, mordenite crystals form columns, and regular hexagonal prism crystals are changed into long column crystals accompanied by cluster small crystals due to the addition of methanol; the action principle of the surfactant is that the surfactant has considerable hydrophilicity, and the strong hydrophilic group enables the surfactant to easily react with the silica-alumina sol to promote the crystallinity to be increased (master academic thesis of Harbin university, 2011). Iwasaki and other researches find that a non-hydrated synthesis medium is beneficial to introducing and highly dispersing silicon in a framework and forming more acid sites, the framework stability and the crystallinity of crystals are higher, and higher toluene alkylation activity is shown; the alcohol solvent has stronger capability of forming hydrogen bonds, not only can shorten the nucleation and crystallization processes of the microporous zeolite and promote the uniform and high dispersion of the nanocrystalline, but also can promote the silicon content and the acidity of the product (Micropor meso pore Mater,2003,64(l-3): 145-.
The invention relates to synthesis of nano aggregated sheet mordenite, which mainly aims to overcome the phenomenon that conventional nano zeolite crystals are easy to agglomerate into spheres due to high surface energy, seriously reduce the mass transfer rate in the catalytic reaction process and be not beneficial to better exertion of catalytic activity. According to the invention, by adding the organic ammonium template and matching with the oxygen-containing organic matter, the mordenite nanocrystals are beneficial to rapid and large-scale nucleation, crystal face growth and regulation and control of the surface energy of the corresponding crystal face are inhibited, the adsorption of alkoxy groups on the crystal face inhibits the rapid growth of the crystal face along the c-axis direction, and through the crystallization process of dissolution-recrystallization, uniform disc-shaped particles are formed by orderly linking the relatively strong surface energy of the crystal face of the b-axis, and meanwhile, the sheet-shaped faces are all 12MR main pore channels along the c-axis. The research discovers that the synthesis rule of the initial structural unit guiding metastable state to stable state three-dimensional nano mordenite is controlled, the integrated synthesis of the nano aggregated sheet-shaped mordenite is optimized, the highly regular nano aggregated sheet-shaped mordenite is synthesized, and the operation purpose is stronger.
Disclosure of Invention
One of the technical problems to be solved by the invention is to synthesize the nano aggregated sheet-shaped mordenite in order to overcome the phenomenon that nano zeolite crystals are easy to agglomerate into spheres due to high surface energy.
The second technical problem to be solved by the present invention is to provide a method for preparing nano aggregated sheet-shaped mordenite which corresponds to the first technical problem.
In order to solve one of the above technical problems, the technical scheme adopted by the invention is as follows:
the sample morphology of the spontaneous aggregation of the nano mordenite crystals in the crystallization process is a sheet shape; the crystallized product is mordenite with MOR configuration, wherein a single nano mordenite is a short columnar crystal, and the three-dimensional size is between 5 and 1000 nm.
In the technical scheme, the nano mordenite crystal with the shape of a sheet of the sample is in a disc shape.
In the technical scheme, the thickness of the sheet-shaped mordenite aggregate is the growth length of a single nano mordenite crystal along the c axisThe degree and the size are 10-500 nm, and the specific surface area of the sheet-shaped mordenite is 300-800 m2/g。
In the technical scheme, the thickness of the sheet-shaped mordenite aggregate is 50-500 nm, and the specific surface area of the sheet-shaped mordenite is 380-600 m2/g。
To solve the second technical problem, the invention adopts the following technical scheme: a method for synthesizing nano aggregated sheet mordenite, which is prepared by the following steps:
(a) preparing a mother solution: the crystallization liquid consists of a silicon source, an aluminum source, an organic template agent T, an organic solvent O and deionized water, wherein the molar SiO is2/Al2O3＝5～50，T/SiO2＝0.01～0.8，O/SiO2＝0.001～1，H2O/SiO2Adjusting the pH value of the mother liquor before crystallization to 9-14 by strong acid or strong base; wherein the concentration of the strong acid is 5-98 wt%, and the concentration of the strong base is 5-80 wt%;
(b) and (3) uniformly stirring the crystallization mother liquor at normal temperature, then putting the crystallization mother liquor into a stainless steel crystallization kettle with a tetrafluoroethylene lining, crystallizing the crystallization mother liquor at the temperature of 80-230 ℃ for 0.5-200 hours, filtering and washing the crystallization mother liquor until the pH value is 7, drying the crystallization mother liquor, and roasting the crystallization mother liquor at the temperature of 450-650 ℃ to obtain the molecular sieve.
In the technical scheme, the silicon source is at least one of water glass, ethyl orthosilicate, white carbon black, silica sol, silicon oxide, activated clay and N- [3- (trimethoxysilyl) propyl ] -N' - (4-vinyl benzyl) ethylenediamine hydrochloride solution; the aluminum source is at least one of aluminum oxide, sodium metaaluminate, aluminum isopropoxide, aluminum nitrate, aluminum sulfate, aluminum chloride and aluminum dihydrogen phosphate; the organic template agent T is at least one selected from tetraethyl ammonium hydroxide and tetraethyl ammonium bromide.
In the technical scheme, the organic solvent O is at least one selected from C1-C6 monoalcohol and isomers thereof, propylene glycol isomers, polyvinyl alcohol PVA, acetone, methyl ether, methyl tert-butyl ether MTBE and anisole. The strong acid is sulfuric acid; the strong base is sodium hydroxide.
In the technical scheme, the organic solvent O is preferably mixed alcohol of methanol and propanol, and the volume ratio of the methanol to the propanol is 0.1-10;
in the technical scheme, the organic solvent O is preferably a mixture of 1, 2-propylene glycol and methyl ether, and the volume ratio of the 1, 2-propylene glycol to the methyl ether is 0.1-10;
in the technical scheme, the organic solvent O is preferably a mixture of acetone, polyvinyl alcohol and isobutanol, and the volume ratio of the acetone to the polyvinyl alcohol to the isobutanol is 0.05-1: 0.05-1;
in the above technical scheme, SiO is preferred2/Al2O3＝20～40，T/SiO2＝0.03～0.2，O/SiO2＝0.005～0.3，H2O/SiO2＝8～20，。
In the technical scheme, the silicon source is preferably water glass or silica sol; the aluminum source is preferably sodium metaaluminate or aluminum sulfate.
According to the method, the oxygen-containing organic auxiliary agent is added to change the chemical environment of a crystallization system, the adsorption of alkoxy groups on the surface of crystal nuclei inhibits the rapid growth of crystal faces along the c-axis direction while a proper amount of organic ammonium template agent induces the rapid nucleation of mordenite, and the crystallization process of dissolution-recrystallization is performed to obtain the nano-crystal aggregated sheet-shaped mordenite. The innovation point of the technology is that the 12MR regularity and the smoothness of the synthesized nano mordenite are improved to a great extent, and the mass transfer diffusion performance is improved due to the aggregation state of the nano mordenite sheets. The method for synthesizing the nano mordenite has controllable technology and cost, the microporous and mesoporous composite pore channel structure is more orderly and regular, and the material can be applied to the industrial production of catalysis and adsorption separation.
Drawings
FIG. 1 is an FE-SEM image of a sample of the molecular sieve prepared in example 1.
FIG. 2 is an FE-SEM photograph of a sample of the molecular sieve prepared in comparative example 1.
FIG. 3 is an FE-SEM image of a sample of the molecular sieve prepared in comparative example 2.
FIG. 4 is an FE-SEM image of a sample of the molecular sieve prepared in comparative example 3.
FIG. 5 is an FE-SEM image of a sample of the molecular sieve prepared in comparative example 4.
The invention is further illustrated by the following examples.
Detailed Description
[ example 1 ]
Dissolving 360 g of silica sol (Ludox-40) in 500 g of water to prepare a solution A; dissolving 60 g of aluminum sulfate in 250 g of water to prepare solution B; 125 grams of tetraethylammonium bromide was dissolved in 150 grams of water to make solution C. Slowly dripping the solution B into the solution A, fully stirring, adding the solution C, then adding 30 ml of methanol (AR), adjusting the pH value of a glue solution to be 13 by adding 20 wt% of sodium hydroxide aqueous solution, fully and uniformly stirring at room temperature, crystallizing the formed gel at 195 ℃ for 30 hours, filtering and drying to obtain a molecular sieve sample.
The SEM morphology of the synthesized sample is shown in figure 1, and the synthesized sample is a disk-shaped sheet molecular sieve formed by connecting uniform columnar mordenite nanocrystals with the three-dimensional size of about 100nm, the thickness of the disk-shaped sheet molecular sieve is about 100nm, and the diameter of the disk-shaped sheet molecular sieve is about 800-1000 nm.
[ example 2 ]
Dissolving 175 g of activated clay in 350 g of water to prepare solution A; dissolving 20 g of alumina in 300 g of water to prepare a solution B; slowly dripping the solution B into the solution A, fully stirring, adding 180 g of tetraethylammonium hydroxide (40%) solution, then adding 26 ml of 1, 2-propylene glycol and 4 ml of methyl ether, adjusting the pH value of a glue solution to be 11 by adding 50 wt% of sodium hydroxide aqueous solution, fully and uniformly stirring at room temperature, crystallizing the formed gel at 180 ℃ for 60 hours, filtering and drying to obtain a molecular sieve sample.
[ example 3 ]
Dissolving 600 g of tetraethoxysilane in 350 g of water to prepare a solution A; dissolving 65 g of aluminum chloride in 300 g of water to prepare a solution B; solution C was prepared by dissolving 136 grams of tetraethylammonium bromide in 150 grams of water. Slowly dropwise adding the solution B into the solution A, fully stirring, adding the solution C, then adding 32 ml of ethanol, adjusting the pH value of the solution to 14 by adding 10 wt% of sodium hydroxide aqueous solution, and carrying out room temperatureStirring thoroughly until a gel is formed at 180 deg.CoCrystallizing at 18 deg.C for 18 hr, filtering, and oven drying to obtain molecular sieve sample.
[ example 4 ]
160 g of white carbon black is dissolved in 350 g of water to prepare solution A; dissolving 80 g of aluminum isopropoxide in 300 g of water to prepare solution B; slowly dripping the solution B into the solution A, fully stirring, adding 180 g of tetraethylammonium hydroxide (40%) solution, then adding 5 ml of methanol and 25 ml of propanol, adjusting the pH value of a glue solution to be 12 by adding 40 wt% of sodium hydroxide aqueous solution, fully and uniformly stirring at room temperature, crystallizing the formed gel at 230 ℃ for 2 hours, filtering and drying to obtain a molecular sieve sample.
[ example 5 ]
160 g of silicon oxide is dissolved in 350 g of water to prepare a solution A; dissolving 30 g of sodium metaaluminate in 300 g of water to prepare a solution B; slowly dripping the solution B into the solution A, fully stirring, adding 180 g of tetraethylammonium hydroxide (40%) solution, then adding 24 ml of isopropanol, adjusting the pH value of a glue solution to be 13.5 by adding 5 wt% of sodium hydroxide aqueous solution, fully and uniformly stirring at room temperature, crystallizing the formed gel at 80 ℃ for 160 hours, filtering and drying to obtain a molecular sieve sample.
[ example 6 ]
Dissolving 175 g of activated clay in 350 g of water to prepare solution A; dissolving 20 g of alumina in 300 g of water to prepare a solution B; slowly dripping the solution B into the solution A, fully stirring, adding 180 g of tetraethylammonium hydroxide (40%) solution, then adding 24 ml of isobutanol, adjusting the pH value of a glue solution to be 13.5 by adding 50 wt% of sodium hydroxide aqueous solution, fully and uniformly stirring at room temperature, crystallizing the formed gel at 180 ℃ for 60 hours, filtering and drying to obtain a molecular sieve sample.
[ example 7 ]
Dissolving 360 g of silica sol (Ludox-40) in 500 g of water to prepare a solution A; dissolving 60 g of aluminum sulfate in 250 g of water to prepare solution B; 125 grams of tetraethylammonium bromide was dissolved in 150 grams of water to make solution C. Slowly dripping the solution B into the solution A, fully stirring, adding the solution C, then adding 30 ml of tert-butyl alcohol, adjusting the pH value of a glue solution to 10.5 by adding 25 wt% of sodium hydroxide aqueous solution, fully and uniformly stirring at room temperature, crystallizing the formed gel at 95 ℃ for 200 hours, filtering and drying to obtain a molecular sieve sample.
[ example 8 ]
Dissolving 360 g of silica sol (Ludox-40) in 500 g of water to prepare a solution A; dissolving 60 g of aluminum sulfate in 250 g of water to prepare solution B; 125 grams of tetraethylammonium bromide was dissolved in 150 grams of water to make solution C. Slowly dripping the solution B into the solution A, fully stirring, adding the solution C, then adding 30 ml of isoamylol, adjusting the pH value of a glue solution to 10 by adding 30 wt% of sodium hydroxide aqueous solution, fully and uniformly stirring at room temperature, crystallizing the formed gel at 195 ℃ for 30 hours, filtering and drying to obtain the molecular sieve sample.
[ example 9 ]
Dissolving 175 g of activated clay in 350 g of water to prepare solution A; dissolving 20 g of alumina in 300 g of water to prepare a solution B; slowly dripping the solution B into the solution A, fully stirring, adding 180 g tetraethylammonium hydroxide (40%) solution, then adding 26 ml of n-amyl alcohol, adjusting the pH value of a glue solution to be 13 by adding 80 wt% of sodium hydroxide aqueous solution, fully and uniformly stirring at room temperature, crystallizing the formed gel at 180 ℃ for 60 hours, filtering and drying to obtain a molecular sieve sample.
[ example 10 ]
160 g of white carbon black is dissolved in 350 g of water to prepare solution A; dissolving 80 g of aluminum isopropoxide in 300 g of water to prepare solution B; slowly dripping the solution B into the solution A, fully stirring, adding 180 g of tetraethylammonium hydroxide (40%) solution, then adding 29 ml of hexanol, adjusting the pH value of a glue solution to be 9 by adding 8 wt% of sodium hydroxide aqueous solution, fully and uniformly stirring at room temperature, crystallizing the formed gel at 180 ℃ for 60 hours, filtering and drying to obtain a molecular sieve sample.
[ example 11 ]
Dissolving 175 g of activated clay in 350 g of water to prepare solution A; dissolving 20 g of alumina in 300 g of water to prepare a solution B; and slowly dripping the solution B into the solution A, fully stirring, adding 180 g of tetraethylammonium hydroxide (40%) solution, then adding 16 ml of acetone, 7 ml of ethylene glycol and 7 ml of isobutanol, adjusting the pH value of a glue solution by adding 10 wt% of sodium hydroxide aqueous solution, fully and uniformly stirring at room temperature, crystallizing the formed gel at 180 ℃ for 60 hours, filtering and drying to obtain a molecular sieve sample.
[ example 12 ]
Dissolving 360 g of silica sol (Ludox-40) in 500 g of water to prepare a solution A; dissolving 60 g of aluminum sulfate in 250 g of water to prepare solution B; 125 grams of tetraethylammonium bromide was dissolved in 150 grams of water to make solution C. Slowly dripping the solution B into the solution A, fully stirring, adding the solution C, then adding 30 ml of anisole, adjusting the pH value of a glue solution to 9.5 by adding a 5 wt% sodium hydroxide aqueous solution, fully and uniformly stirring at room temperature, crystallizing the formed gel at 195 ℃ for 30 hours, filtering and drying to obtain a molecular sieve sample.
[ example 13 ]
375 g of N- [3- (trimethoxysilyl) propyl ] -N' - (4-vinylbenzyl) ethylenediamine hydrochloride solution is dissolved in water to prepare a solution A; dissolving 20 g of alumina in 300 g of water to prepare a solution B; slowly dripping the solution B into the solution A, fully stirring, adding 180 g of tetraethylammonium hydroxide (40%) solution, then adding 26 ml of methyl tert-butyl ether MTBE, adjusting the pH value of a glue solution to be 11 by adding 18 wt% of sodium hydroxide aqueous solution, fully and uniformly stirring at room temperature, crystallizing the formed gel at 180 ℃ for 60 hours, filtering and drying to obtain a molecular sieve sample.
[ example 14 ]
Dissolving 600 g of water glass in 350 g of water to prepare solution A; dissolving 65 g of aluminum nitrate in 300 g of water to prepare a solution B; slowly dripping the solution B into the solution A, fully stirring, adding 180 g of tetraethylammonium hydroxide (40%) solution, then adding 26 ml of 1, 3-propylene glycol, adjusting the pH value of a glue solution to be 12 by using 96.5 wt% of concentrated sulfuric acid, fully and uniformly stirring at room temperature, crystallizing the formed gel at 180 ℃ for 9 hours, filtering and drying to obtain a molecular sieve sample.
[ example 15 ]
Dissolving 360 g of silica sol (Ludox-40) in 500 g of water to prepare a solution A; dissolving 60 g of aluminum sulfate in 250 g of water to prepare solution B; 125 grams of tetraethylammonium bromide was dissolved in 150 grams of water to make solution C. Slowly dripping the solution B into the solution A, fully stirring, adding the solution C, then adding 15 ml of polyvinyl alcohol PVA, adjusting the pH value of a glue solution to be 13.5 by adding 40 wt% of sodium hydroxide aqueous solution, fully and uniformly stirring at room temperature, crystallizing the formed gel at 195 ℃ for 30 hours, filtering and drying to obtain a molecular sieve sample.
[ example 16 ]
160 g of white carbon black is dissolved in 350 g of water to prepare solution A; dissolving 80 g of aluminum dihydrogen phosphate in 300 g of water to prepare a solution B; slowly dripping the solution B into the solution A, fully stirring, adding 180 g of tetraethylammonium hydroxide (40%) solution, then adding 29 ml of acetone, adjusting the pH value of the glue solution to be 13 by adding 35 wt% of sodium hydroxide aqueous solution, fully and uniformly stirring at room temperature, crystallizing the formed gel at 180 ℃ for 60 hours, filtering and drying to obtain the molecular sieve sample.
[ example 17 ]
Dissolving 175 g of activated clay in 350 g of water to prepare solution A; dissolving 60 g of aluminum perchlorate in 300 g of water to prepare solution B; slowly dripping the solution B into the solution A, fully stirring, adding 180 g of tetraethylammonium hydroxide (40%) solution, then adding 26 ml of methyl ether, adjusting the pH value of the glue solution to 10 by adding 20 wt% of sodium hydroxide aqueous solution, fully and uniformly stirring at room temperature, crystallizing the formed gel at 180 ℃ for 60 hours, filtering and drying to obtain the molecular sieve sample.
[ COMPARATIVE EXAMPLE 1 ]
Gel was formed as in example 1, without adding 30 ml of methanol (AR), the homogeneous stirred gel was crystallized at room temperature for 30 hours according to the crystallization procedure of example 1, filtered and dried to obtain a molecular sieve sample.
The SEM morphology of the synthesized sample is shown in FIG. 2, the size distribution of the crystal grains is not uniform, shuttle-shaped large crystal grains with the length of about 1 μm exist, irregular blocks are formed by agglomeration of the large and small crystal grains, and the disc-shaped plate-shaped molecular sieve cannot be obtained.
[ COMPARATIVE EXAMPLE 2 ]
Forming gel according to the example 2, adding no organic ammonium template agent, and performing hydrothermal crystallization at 180 ℃, wherein the crystallinity of the product is still low after 30 hours, and the amorphous form accounts for a large proportion of the solid content; and after crystallization for 50 hours, filtering and drying to obtain a molecular sieve sample.
The SEM morphology of the synthesized sample is shown in FIG. 3, and the obtained non-uniform fusiform large grains with the length of about 3 μm are micron-sized mordenite, and the large grains are distributed disorderly, so that the disc-shaped plate-shaped molecular sieve cannot be obtained.
[ COMPARATIVE EXAMPLE 3 ]
Gel is formed according to the embodiment 1, tetraethylammonium bromide is increased to 500 g, the gel which is stirred uniformly under the condition of room temperature is crystallized for 30 hours according to the crystallization procedure of the embodiment 1, and a molecular sieve sample is obtained after filtration and drying.
The SEM morphology of the synthesized sample is shown in FIG. 4, the grain size distribution is relatively uniform, the mordenite nanocrystals with the length of about 500nm and the width of about 200nm are obtained, the grains are basically agglomerated into a spherical shape, and the disc-shaped sheet molecular sieve cannot be obtained.
[ COMPARATIVE EXAMPLE 4 ]
The gel is formed according to the example 1, the adding amount of the methanol is increased to 300 ml, the gel which is stirred uniformly under the condition of room temperature is crystallized for 30 hours according to the crystallization procedure of the example 1, and a molecular sieve sample is obtained after filtration and drying.
The SEM appearance of the synthesized sample is shown in FIG. 5, the appearance is relatively disordered, and irregular blocks are formed by agglomeration of blocky or long-strip nanocrystals, so that the disc-shaped sheet molecular sieve cannot be obtained. The presence of ZSM-5 heterocrystals was found by XRD phase characterization.
TABLE 1
Claims (9)
1. A method for preparing nano-aggregated sheet-shaped mordenite is characterized in that the sample morphology of the spontaneous aggregation of nano-mordenite crystals in the crystallization process is sheet-shaped; the crystallized product is mordenite with MOR configuration, wherein a single nano mordenite is a short columnar crystal, and the three-dimensional size of the single nano mordenite is between 5 and 1000 nm;
the preparation method of the nano aggregated sheet-shaped mordenite comprises the following steps:
(a) preparing a mother solution: the crystallization liquid consists of a silicon source, an aluminum source, an organic template agent T, an organic solvent O and deionized water according to a molar ratio of SiO2/Al2O3＝5～50，T/SiO2＝0.01～0.8，O/SiO2＝0.001～1，H2O/SiO2Adjusting the pH value of the mother liquor before crystallization to 9-14 by strong acid or strong base; wherein the concentration of the strong acid is 5-98 wt%, and the concentration of the strong base is 5-80 wt%;
(b) uniformly stirring the crystallization mother liquor at normal temperature, then putting the crystallization mother liquor into a stainless steel crystallization kettle with a tetrafluoroethylene lining, crystallizing the crystallization mother liquor at the temperature of 80-230 ℃ for 0.5-200 hours, filtering and washing the crystallization mother liquor until the pH value is 7, drying the crystallization mother liquor, and roasting the crystallization mother liquor at the temperature of 450-650 ℃ to obtain a molecular sieve;
wherein the organic solvent O used in the step (a) is at least one selected from C1-C6 monoalcohol and isomer thereof, propylene glycol isomer, polyvinyl alcohol PVA, acetone, methyl ether, methyl tert-butyl ether MTBE and anisole.
2. A process for the preparation of nano-aggregated platelet-shaped mordenite according to claim 1, wherein the silicon source used in step (a) is at least one of water glass, ethyl orthosilicate, silica fume, silica sol, silica oxide, activated clay, N- [3- (trimethoxysilyl) propyl ] -N' - (4-vinylbenzyl) ethylenediamine hydrochloride solution; the aluminum source is at least one of aluminum oxide, sodium metaaluminate, aluminum isopropoxide, aluminum nitrate, aluminum sulfate, aluminum chloride and aluminum dihydrogen phosphate; the organic template agent T is at least one selected from tetraethyl ammonium hydroxide and tetraethyl ammonium bromide.
3. A process for the preparation of nano-aggregated platelet-shaped mordenite according to claim 1, characterized in that the strong acid used in step (a) is sulfuric acid; the strong base is sodium hydroxide.
4. A process for the preparation of a nano-aggregated sheet-shaped mordenite according to claim 1, wherein in step (a), SiO is applied2/Al2O3＝20～40，T/SiO2＝0.03～0.2，O/SiO2＝0.005～0.3，H2O/SiO2＝8～20。
5. A process for the preparation of nano-aggregated sheet-shaped mordenite as claimed in claim 2, characterized in that the source of silicon is selected from the group consisting of water glass or silica sol; the aluminum source is selected from sodium metaaluminate or aluminum sulfate.
6. A nano-aggregated sheet-shaped mordenite which is characterized by being prepared by the preparation method of any one of claims 1 to 5.
7. The nano-aggregated platelet-shaped mordenite of claim 6, wherein the nano-mordenite crystals having a sample morphology in the form of platelets have a disk shape.
8. A nano-aggregated platelet-shaped mordenite according to claim 6, wherein the thickness of said platelet-shaped mordenite aggregate is the growth length of a single nano-mordenite crystal along the c-axis, and the size is 10 to 800nm, and the specific surface area of said platelet-shaped mordenite is 300 to 800m2/g。
9. A nano-aggregated platelet-shaped mordenite according to claim 6, wherein the thickness of said platelet-shaped mordenite aggregate is 50 to 500nm, and the specific surface area of said platelet-shaped mordenite is in the range of 380 to 600m2/g。
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1243100A (en) * | 1998-07-29 | 2000-02-02 | 中国科学院大连化学物理研究所 | Synthesizing method for high-silicon mordenite |
| CN1666956A (en) * | 2005-02-04 | 2005-09-14 | 华东理工大学 | Method for synthesizing nanometer size mordenite |
| CN1843915A (en) * | 2006-05-08 | 2006-10-11 | 浙江大学 | Method for synthesizing high-silicon mordenite in the absence of amine |
| CN102190316A (en) * | 2010-03-03 | 2011-09-21 | 中国石油化工股份有限公司 | Method for synthesizing mesoporous mordenite |
| CN102605957A (en) * | 2012-03-09 | 2012-07-25 | 三一重工股份有限公司 | Prestress reinforced boom, prestress reinforced support leg and pump truck |
| CN103482645A (en) * | 2013-09-22 | 2014-01-01 | 华东师范大学 | Preparation method for nanometer mordenite molecular sieve with multi-stage holes |
| CN103601213A (en) * | 2013-12-06 | 2014-02-26 | 天津大学 | Preparation method for low silicon-aluminum ratio nanosheet flower cluster-like mordenite molecular sieve |
| CN104276586A (en) * | 2013-07-03 | 2015-01-14 | 中国石油大学(北京) | Preparation method of mordenite |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101600575B1 (en) * | 2014-01-24 | 2016-03-08 | 인하대학교 산학협력단 | Method for manufacturing of meso-microporous mordenite in form of plate and meso-microporous mordenite in form of plate thereby |
-
2016
- 2016-08-23 CN CN201610707697.5A patent/CN107758685B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1243100A (en) * | 1998-07-29 | 2000-02-02 | 中国科学院大连化学物理研究所 | Synthesizing method for high-silicon mordenite |
| CN1666956A (en) * | 2005-02-04 | 2005-09-14 | 华东理工大学 | Method for synthesizing nanometer size mordenite |
| CN1843915A (en) * | 2006-05-08 | 2006-10-11 | 浙江大学 | Method for synthesizing high-silicon mordenite in the absence of amine |
| CN102190316A (en) * | 2010-03-03 | 2011-09-21 | 中国石油化工股份有限公司 | Method for synthesizing mesoporous mordenite |
| CN102605957A (en) * | 2012-03-09 | 2012-07-25 | 三一重工股份有限公司 | Prestress reinforced boom, prestress reinforced support leg and pump truck |
| CN104276586A (en) * | 2013-07-03 | 2015-01-14 | 中国石油大学(北京) | Preparation method of mordenite |
| CN103482645A (en) * | 2013-09-22 | 2014-01-01 | 华东师范大学 | Preparation method for nanometer mordenite molecular sieve with multi-stage holes |
| CN103601213A (en) * | 2013-12-06 | 2014-02-26 | 天津大学 | Preparation method for low silicon-aluminum ratio nanosheet flower cluster-like mordenite molecular sieve |
Non-Patent Citations (2)
| Title |
|---|
| Catalytic Properties of Hierarchical Mordenite Nanosheets Synthesized by Self-Assembly Between Subnanocrystals and Organic Templates;Min Liu et al;《Catal Lett》;20150928;实验部分 * |
| 不同形貌丝光沸石的合成与表征;孔鹊;《中国优秀硕士学位论文全文数据库·工程科技I辑》;20130915;全文 * |
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