CN110550641B - Structure directing agent for synthesizing germanium-containing L-type molecular sieve and application - Google Patents

Structure directing agent for synthesizing germanium-containing L-type molecular sieve and application Download PDF

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CN110550641B
CN110550641B CN201810565496.5A CN201810565496A CN110550641B CN 110550641 B CN110550641 B CN 110550641B CN 201810565496 A CN201810565496 A CN 201810565496A CN 110550641 B CN110550641 B CN 110550641B
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molecular sieve
directing agent
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germanium
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杨尚
王嘉欣
丁璟
臧高山
张玉红
于宁
王涛
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Sinopec Research Institute of Petroleum Processing
China Petroleum and Chemical Corp
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    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
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    • 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
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Abstract

The invention relates to a structure directing agent for synthesizing a germanium-containing L-type molecular sieve and application thereof, wherein the structure directing agent comprises the following components in mole: (6-20) M: al (Al)2O3：(0.1‑1.8)GeO2：(8‑25)SiO2：(150‑500)H2O, where M is K2O or is K2O and Na2A combination of O. The L-shaped molecular sieve prepared by the structure directing agent provided by the invention is used for preparing an aromatization catalyst, has higher reaction activity and aromatic selectivity, and has obviously improved activity stability compared with a catalyst prepared by a silicon-aluminum L-shaped molecular sieve.

Description

Structure directing agent for synthesizing germanium-containing L-type molecular sieve and application
Technical Field
The invention relates to a germanium-containing molecular sieve synthesis guiding agent and application thereof, in particular to a structure guiding agent for synthesizing a germanium-containing L-shaped molecular sieve and application thereof.
Background
L-type molecular sieves (International molecular Sieve Association code: LTL) are artificially synthesized molecular sieves developed by Union Carbide in 1965, and no equivalent has been found in nature so far. The L-type molecular sieve is an alkaline large-pore molecular sieve, the crystal of the L-type molecular sieve is cylindrical, the L-type molecular sieve has a one-dimensional pore channel structure which is parallel to the axial direction of the cylinder, the L-type molecular sieve is formed by stacking alternating hexagonal cylinder cages and cancrinite cages in the C-axis direction, and the L-type molecular sieve rotates according to a six-fold axis to generate a twelve-membered ring pore channel, wherein the pore diameter of the twelve-membered ring channel is 0.71nm, and the kinetic diameter of. The typical chemical composition formula of the L-type molecular sieve is as follows:
(0.9～1.3)M2/nO：Al2O3：xSiO2：yH2O，
wherein M is a metal ion, the most predominant metal ion is K+Or by other alkali or alkaline earth metal ions, but generally more than 90% of K in the L zeolite+Are not easily exchanged. n is the valence of M, x is 5-7, and y is 0-9.
Since Bernard (proc.5th int.conf.on Zeolites, Wiley, New York,1980,68) found that PtKL has much higher activity and selectivity for aromatization of n-hexane than conventional bifunctional catalysts, platinum-supported L-type molecular sieves have gained widespread interest as n-alkane dehydrocyclization catalysts. Subsequently, Chevron and EXXON applied for a number of patents on PtKL type molecular sieve catalysts for dehydrogenation and reforming reactions and achieved commercial application of the catalysts.
The zeolite synthesized by using the directing agent is widely applied to the processes of synthesizing ZSM-5, Beta, A type molecular sieves, faujasite and the like. The structure-directing agent is added in the synthesis process, which is helpful for the nucleation and growth of zeolite and can reduce mixed crystals to a certain extent.
CN103936025A discloses a synthesis method of a metal heteroatom-containing LTL structure molecular sieve, wherein an organic template is adopted in the synthesis method to synthesize an L-type molecular sieve containing heteroatoms such as iron, nickel and the like.
CN104271242A discloses catalysts prepared from various germanium-containing materials, wherein the germanium content of the catalyst is 0.1 wt% to 10 wt%, but the influence of L-type molecular sieve containing trace germanium on alkane aromatization performance of PtKL catalyst system has not been reported so far.
Disclosure of Invention
The invention aims to provide a structure directing agent for synthesizing a germanium-containing L-shaped molecular sieve and a method for synthesizing the germanium-containing L-shaped molecular sieve by using the structure directing agent.
The invention provides a structure directing agent for synthesizing a germanium-containing L-type molecular sieve, which comprises the following components in mole: (6-20) M: al (Al)2O3：(0.1-1.8)GeO2：(8-25)SiO2：(150-500)H2O, where M is K2O or is K2O and Na2A combination of O.
Preferably, the structure directing agent has a molar composition of: (6-12) M: al (Al)2O3：(0.2-1.2)GeO2：(8-20)SiO2：(200-400)H2O。
The invention also provides a preparation method of the provided structure directing agent, which comprises the steps of mixing, stirring and aging the inorganic alkali, the germanium source, the aluminum source, the silicon source and the water according to the molar composition of the structure directing agent.
The invention also provides a synthesis method of the germanium-containing L-type molecular sieve, which comprises the following steps:
mixing the structure directing agent, inorganic base, aluminum source, silicon source and water to obtain reaction gel; wherein the molar composition of the reaction gel is as follows: (6-20) SiO2：Al2O3：(0.01-0.09)GeO2：(1-6)M：(80-300)H2O; preferably (10-15) SiO2：Al2O3：(0.02-0.06)GeO2：(2-6)M：(140-300)H2O；
Carrying out hydrothermal crystallization on the obtained reaction gel, washing and drying a solid product obtained after crystallization to obtain the L-shaped molecular sieve; wherein the L-type molecular sieve has the chemical composition as follows: (0.8-1.3) M (0.001-0.007) GeO2·Al2O3·(4-7)SiO2Preferably (1.0-1.3) M (0.001-0.006) GeO2·Al2O3·(4-7)SiO2。
The structure directing agent contains germanium, and when the structure directing agent is used for preparing the L-shaped molecular sieve containing trace germanium in the framework, the prepared molecular sieve has smaller height-diameter, is used for preparing an aromatization catalyst, and has good aromatization activity, selectivity and activity stability.
Drawings
FIG. 1 is an XRD spectrum of raw Ge-containing L-type molecular sieve powders GL-1, GL-2 and GL-3 prepared in examples 4, 5 and 6 of the present invention.
FIG. 2 is an SEM picture of raw Ge-containing L-type molecular sieve GL-2 prepared in example 5 of the present invention.
FIG. 3 is an SEM picture of raw Ge-containing L-type molecular sieve GL-3 prepared in example 6 of the present invention.
FIG. 4 is an SEM photograph of raw Ge-free L-type molecular sieve powder L-1 prepared in comparative example 1 of the present invention.
FIG. 5 is an SEM image of DGL-2 of Ge-containing L-type molecular sieve raw powder prepared in comparative example 3 of the present invention.
FIG. 6 is an SEM image of DGL-3 of Ge-containing L-type molecular sieve raw powder prepared in comparative example 4 of the present invention.
Detailed Description
The structure directing agent for synthesizing the germanium-containing L-shaped molecular sieve contains germanium, and the germanium-containing L-shaped molecular sieve synthesized by the structure directing agent can increase the regularity of the crystal grain shape of the molecular sieve, reduce the height-diameter ratio and reduce the generation of small crystal grains. When the catalyst is used for aromatization reaction, the mass transfer effect can be increased, and the reaction activity, the aromatic selectivity and the stability are improved.
The preparation method of the structure directing agent comprises the steps of mixing, stirring and aging the inorganic base, the germanium source, the aluminum source, the silicon source and the water according to the molar composition of the structure directing agent, wherein the aging temperature can be 20-60 ℃, preferably 25-35 ℃, and the aging time can be 10-120 hours, preferably 24-72 hours. The structure directing agent has high silicon-aluminum ratio and alkali-silicon ratio, can induce crystallization reaction, makes the reaction easy to nucleate and shortens crystallization time.
In the synthesis method of the invention, the temperature of the hydrothermal crystallization can be 100-.
In the preparation method and the synthesis method of the present invention, the raw materials for preparing the structure directing agent and the reaction gel may be the same or different, for example, the inorganic base may be potassium hydroxide or a mixture of potassium hydroxide and sodium hydroxide, the germanium source may be at least one selected from germanium dioxide, germanium chloride and germanium hydroxide, preferably germanium dioxide, the silicon source may be silica sol, the silica content in the silica sol may be 20 to 45 mass%, preferably 25 to 40 mass%, the aluminum source may be hydrated alumina and/or metaaluminate, and the metaaluminate may be potassium metaaluminate and/or sodium metaaluminate. Al in the structure directing agent2O3Accounting for Al in the reaction gel2O3The molar ratio of (B) may be 1 to 5%, preferably 2 to 5%.
The L-shaped molecular sieve containing germanium synthesized by the method is suitable for paraffin aromatization reaction after loading platinum, and the content of the loaded platinum can be 0.5-1.5 percent by mass. The platinum in the molecular sieve can be loaded by adopting an impregnation method, and then drying and roasting are carried out, wherein the liquid/solid volume ratio in the impregnation can be (2-6): 1. the platinum-containing compound used for impregnation is preferably tetraamineplatinum dichloride, hexachloroplatinic acid or hexahydroxyplatinic acid.
The method for aromatization by the L-shaped molecular sieve synthesized by the invention comprises the following steps: the aromatization raw material is contacted with the L-shaped molecular sieve loaded with platinum provided by the invention and aromatization reaction is carried out under the hydrogen condition. The aromatization feedstock may be C6-C7Alkane of (2), preferably C6-C7The temperature of aromatization reaction of the straight-chain alkane can be 450-550 ℃, the pressure can be 0.5-2 MPa, and the hourly space velocity of the feeding liquid can be 1-5h-1The hydrogen/hydrocarbon volume ratio may be (500-: 1.
the invention is further illustrated, but not limited, by the following examples.
In the examples and comparative examples of the present invention, the prepared molecular sieve was analyzed by X-ray powder diffraction under the following conditions: cu target, Ka radiation, Ni filter, tube voltage of 45kV, tube current of 250mA, scanning range of 0.5-50 degrees and step width of 0.02 degrees.
The relative crystallinity calculation method comprises the following steps: summarizing data obtained by a diffractometer into a text document format, drawing a phase atlas by JADE5.0 software, searching peaks and performing integral calculation to obtain peak areas of characteristic peaks with 2 theta angles of 14.7, 19.3, 22.6, 24.3, 25.5, 28.0, 29.0 and 30.6 respectively, summing the peak areas of the characteristic peaks at 8 positions, and obtaining the ratio of the sum of the peak areas of the characteristic peaks at 8 positions obtained by a standard sample under the same analysis condition, namely the relative crystallinity of the characteristic peaks. The standard sample is L-type molecular sieve crystal produced by Changling catalyst factory.
The chemical composition of the molecular sieve is determined by X-ray fluorescence spectrometry, and the types of the adopted instruments are as follows: model 3013X-ray fluorescence analyzer from japan physical and electronic products corporation.
The scanning electron microscope was used as a Scanning Electron Microscope (SEM) model number Hitachi S-4800.
Examples 1-3 the structure directing agents of the present invention were prepared.
Example 1
According to the molar composition of the feeding mixture of 8K2O·Al2O3·GeO2·14SiO2·320H2Formulation of O, 4.31g GeO2And 6g of hydrated alumina (alumina content: 70% by mass, the same applies hereinafter) were added to 168.51g of a solution containing 36.89g of KOH, and the mixture was dissolved by heating to obtain a mixed solution. 138.35g of silica sol (containing 25% by mass of SiO) were stirred2pH 9, the same applies below) was added to the mixture preheated to 50 ℃ and stirred for 0.5 hour to form a reaction gel, which was aged at 34 ℃ for 72 hours to obtain a translucent sol as a structure directing agent.
Example 2
A structure directing agent was prepared according to the method of example 1 except that the aging temperature was 40 ℃ and the aging time was 24 hours.
Example 3
According to the molar composition of the feeding mixture of 8K2O·Al2O3·0.6GeO2·14SiO2·320H2Formulation of O, 2.58g GeO2And 6g of hydrated alumina were added to 168.51g of a solution containing 36.89g of KOH, and the mixture was dissolved by heating. The mixed solution was added to 138.35g of silica sol preheated to 50 ℃ with stirring to form a reaction gel with stirring for 0.5 hour, and the reaction gel was aged at 34 ℃ for 72 hours to obtain a translucent sol as a structure directing agent.
Examples 4-6 were used to prepare the L-type molecular sieves of the present invention.
Example 4
The structure directing agent prepared in example 1 was used to synthesize the L-type molecular sieve.
5.01g of hydrated alumina was added to 43.31g of a solution containing 9.97g of KOH, and the mixture was dissolved by heating to obtain a mixed solution, and the mixed solution was added to 81.52g of silica sol with stirring, and 8.19g of the structure directing agent prepared in example 1 was added thereto, and stirred for 0.5 hour to form a reaction gel having a molar composition: 10SiO 22·Al2O3·0.03GeO2·2.75K2O·160H2O, Al in the structure directing agent2O3Accounting for Al in the reaction gel2O3The molar ratio of (B) was 3.0%.
And (2) transferring the reaction gel into a reaction kettle, crystallizing at 170 ℃ for 48 hours, then quickly cooling to 40 ℃, centrifugally separating and washing a product until the pH value of a liquid phase is 10-11, drying the obtained solid at 120 ℃ for 10 hours to obtain germanium-containing L-type molecular sieve raw powder GL-1, wherein an X-ray powder diffraction analysis spectrogram of the molecular sieve raw powder is shown in figure 1, the relative crystallinity is 98%, and the chemical composition of the molecular sieve is as follows: 1.02K2O·0.003GeO2·Al2O3·5.28SiO2。
Example 5
The structure directing agent prepared in example 2 was used to synthesize the L-type molecular sieve.
2.95g of hydrated alumina was added to 24.25g of a solution containing 5.60g of KOH, and the mixture was dissolved by heating to obtain a mixed solution, and the mixed solution was added to 47.48g of silica sol with stirring, and 8.19g of the structure directing agent prepared in example 2 was added thereto, and stirred for 0.5 hour to form a reaction gel having a molar composition: 10SiO 22·Al2O3·0.05GeO2·2.75K2O·160H2O, Al in the structure directing agent2O3Accounting for Al in the reaction gel2O3The molar ratio of (B) was 5.0%.
And (2) transferring the reaction gel into a reaction kettle, crystallizing at 170 ℃ for 48 hours, then rapidly cooling to 40 ℃, centrifugally separating and washing a product until the pH value of a liquid phase is 10-11, drying the obtained solid at 120 ℃ for 10 hours to obtain the germanium-containing L-type molecular sieve raw powder GL-2, wherein an X-ray powder diffraction analysis spectrogram is shown in figure 1, a Scanning Electron Microscope (SEM) diagram is shown in figure 2, the relative crystallinity is 97%, and the chemical composition of the molecular sieve is as follows: 0.98K2O·0.004GeO2·Al2O3·5.01SiO2。
Example 6
The structure directing agent prepared in example 3 was used to synthesize the L-type molecular sieve.
3.72g of hydrated alumina was added to 31.40g of a solution containing 7.24g of KOH, and the mixture was dissolved by heating to obtain a mixed solution, and the mixed solution was added to 60.25g of silica sol with stirring, and 8.15g of the structure directing agent prepared in example 3 was added thereto, and stirred for 0.5 hour to form a reaction gel having a molar composition: 10SiO 22·Al2O3·0.024GeO2·2.75K2O·160H2O, Al in the structure directing agent2O3Accounting for Al in the reaction gel2O3The molar ratio of (B) was 4.0%.
And (2) transferring the reaction gel into a reaction kettle, crystallizing at 170 ℃ for 48 hours, then quickly cooling to 40 ℃, centrifugally separating and washing a product until the pH value of a liquid phase is 10-11, drying the obtained solid at 120 ℃ for 10 hours to obtain the germanium-containing L-type molecular sieve raw powder GL-3, wherein an X-ray powder diffraction analysis spectrogram is shown in figure 1, an SEM is shown in figure 3, the relative crystallinity is 98%, and the chemical composition of the molecular sieve is as follows: 1.05K2O·0.002GeO2·Al2O3·5.75SiO2。
Comparative example 1
Preparing the germanium-free L-type molecular sieve.
According to the molar composition of the feeding mixture of 8K2O·Al2O3·14SiO2·320H2Formulation of O, mixing 6g of waterAlumina was added to 132g of a solution containing 36.89g of KOH, and the mixture was dissolved by heating. Adding the mixed solution into 138g of silica sol preheated to 50 ℃ under stirring, stirring for 0.5 hour to form reaction gel, and aging the reaction gel at 34 ℃ for 72 hours to obtain semitransparent sol serving as a guiding agent.
Adding 5.01g of hydrated alumina into 43.31g of a solution containing 9.97g of KOH, heating and dissolving to obtain a mixed solution, adding the mixed solution into 81.52mL of silica sol under stirring, adding 8.08g of the directing agent, and stirring for 0.5 hour to form a reaction gel, wherein the molar composition of the reaction gel is as follows: 10SiO 22·Al2O3·2.75K2O·160H2And O. Al in the directing agent2O3Accounting for Al in the reaction gel2O3The molar ratio of (B) was 3.0%.
And (3) transferring the reaction gel into a reaction kettle, crystallizing for 72 hours at 170 ℃, then quickly cooling to 40 ℃, centrifugally separating and washing a product until the pH value of a liquid phase is 10-11, drying the obtained solid for 10 hours at 120 ℃ to obtain L-type molecular sieve raw powder L-1, wherein the SEM picture is shown in figure 4, the relative crystallinity is 99%, and the chemical composition of the molecular sieve is as follows: 1.16K2O·Al2O3·6.44SiO2。
Comparative example 2
According to the molar composition of the feeding mixture of 8K2O·Al2O3·2GeO2·14SiO2·320H2Formulation of O, 8.61g GeO2And 6g of hydrated alumina were added to 168.51g of a solution containing 36.89g of KOH, and the mixture was dissolved by heating. Adding the mixed solution into 138.35g of silica sol preheated to 50 ℃ under stirring, stirring for 0.5 hour to form reaction gel, and aging the reaction gel at 34 ℃ for 72 hours to obtain translucent sol and obtain the high-germanium structure directing agent.
Adding 2.95g of hydrated alumina into 24.25g of solution containing 5.60g of KOH, heating and dissolving to obtain a mixed solution, adding the mixed solution into 47.48g of silica sol under stirring, adding 8.30g of the high germanium structure directing agent prepared in the comparative example and Al in the directing agent2O3Accounting for Al in the reaction gel2O3Is 5.0 percent, stirringA reaction gel was formed in 0.5 hours, having a molar composition of: 10SiO 22·Al2O3·0.1GeO2·2.75K2O·160H2O。
And (2) transferring the reaction gel into a reaction kettle, crystallizing at 170 ℃ for 48 hours, then quickly cooling to 40 ℃, centrifugally separating and washing a product until the pH value of a liquid phase is 10-11, drying the obtained solid at 120 ℃ for 10 hours to obtain germanium-containing L-type molecular sieve raw powder DGL-1, wherein the relative crystallinity is 67%, and the chemical composition of the molecular sieve is as follows: 1.18K2O·0.008GeO2·Al2O3·6.05SiO2。
Comparative example 3
Using the structure directing agent prepared in comparative example 1, the synthetic formulation 10SiO in example 6 was followed2·Al2O3·0.024GeO2·2.75K2O·160H2And O, adding germanium dioxide into a KOH solution to synthesize the germanium-containing L-type molecular sieve DGL-2, wherein the relative crystallinity is 108 percent, and the chemical composition of the molecular sieve is as follows: 1.2K2O·0.001GeO2·Al2O3·5.21SiO2The SEM image is shown in FIG. 5.
Comparative example 4
Using the structure directing agent prepared in comparative example 1, the synthetic formulation 10SiO in example 5 was followed2·Al2O3·0.05GeO2·2.75K2O·160H2O, 5.01g of hydrated alumina was added to 43.50g of a solution containing 9.97g of KOH and 0.19g of GeO2Heating and dissolving to obtain a mixed solution, adding the mixed solution to 81.52g of silica sol under stirring, adding 8.08g of the directing agent prepared in comparative example 1 and Al in the structure directing agent2O3Accounting for Al in the reaction gel2O3The molar ratio of the germanium-containing L-type molecular sieve DGL-3 is 3.0%, stirring is carried out for 0.5 hour to form reaction gel, the reaction gel is transferred into a reaction kettle and crystallized for 72 hours at the temperature of 170 ℃, then the reaction gel is rapidly cooled to 40 ℃, a product is subjected to centrifugal separation and washing until the pH value of a liquid phase is 10-11, the obtained solid is dried for 10 hours at the temperature of 120 ℃, the germanium-containing L-type molecular sieve DGL-3 is synthesized, the relative crystallinity is 116%, and the chemical composition of the molecular sieve is as follows: 1.10K2O·0.002GeO2·Al2O3·5.95SiO2The SEM image is shown in FIG. 6.
Examples 7 to 9
Examples 7-9 the aromatization performance of each of the germanium-containing L-type molecular sieves of examples 4-6 was evaluated.
Taking 5g of the germanium-containing L-shaped molecular sieve prepared by the invention as a carrier, and respectively taking Pt (NH) with the concentration of 16mg/mL3)2Cl2And (3) supersaturating and dipping the solution, wherein the liquid/solid volume ratio during dipping is 4: 1, drying the impregnated solid at 120 ℃ for 12 hours, and calcining the solid at 350 ℃ for 4 hours to prepare a catalyst having a Pt content of 1.0 mass%, wherein the catalyst numbers of the respective examples and the platinum and germanium contents of the molecular sieve support and the catalyst used are shown in Table 1.
2.5mL of catalyst is filled on a high-pressure micro-reactor, and n-hexane is used as a raw material to carry out aromatization reaction, wherein the reaction temperature is 500 ℃, the pressure is 1.0MPa, and the hourly space velocity of a feeding liquid is 3h-1Hydrogen/hydrocarbon volume ratio 1200: 1, the results are shown in table 1.
Comparative examples 5 to 8
Comparative examples 5 to 8 the aromatization reaction performance of each of the L-type molecular sieves of comparative examples 1 to 4 was evaluated in the same manner as in examples 7 to 9, and the results are shown in Table 1.
Comparative example 9
5g of the raw powder L-1 of the L-type molecular sieve synthesized in comparative example 1 was used as a carrier, and Pt (NH) was added at a concentration of 16mg/mL3)2Cl2Solution and containing GeO2The alkaline solution of (2), the liquid/solid volume ratio at impregnation being 4: 1, drying the impregnated solid at 120 ℃ for 12 hours, and roasting the solid at 350 ℃ for 4 hours to prepare the catalyst DC-5 with the Pt content of 1.0 mass% and the Ge content of 0.05 mass%.
2.5mL of catalyst is filled on a high-pressure micro-reactor, and n-hexane is used as a raw material to carry out aromatization reaction, wherein the reaction temperature is 500 ℃, the pressure is 1.0MPa, and the hourly space velocity of a feeding liquid is 3h-1Hydrogen/hydrocarbon volume ratio 1200: 1, the results are shown in table 1.
TABLE 1
Figure BDA0001684304580000101

Claims (10)

1. A structure directing agent for synthesizing a germanium-containing L-type molecular sieve, which comprises the following components in molar composition: (6-20) M: al (Al)2O3：(0.1-1.8)GeO2：(8-25)SiO2：(150-500)H2O, where M is K2O or is K2O and Na2A combination of O.
2. The structure directing agent of claim 1, wherein the structure directing agent has a molar composition of: (6-12) M: al (Al)2O3：(0.2-1.2)GeO2：(8-20)SiO2：(200-400)H2O。
3. A process for preparing a structure directing agent as defined in claim 1 or 2, comprising mixing, stirring and aging the inorganic base, germanium source, aluminum source, silicon source and water according to the molar composition of the structure directing agent at a temperature of 20 to 60 ℃ for a time of 10 to 120 hours.
4. The preparation method according to claim 3, wherein the inorganic base is potassium hydroxide or a mixture of sodium hydroxide and potassium hydroxide, the silicon source is silica sol, the aluminum source is hydrated alumina and/or metaaluminate, and the germanium source is at least one selected from germanium dioxide, germanium chloride and germanium hydroxide.
5. A method for synthesizing a germanium-containing L-type molecular sieve comprises the following steps:
mixing the structure directing agent of claim 1 or 2, an inorganic base, an aluminum source, a silicon source, and water to obtain a reaction gel; wherein the molar composition of the reaction gel is as follows: (6-20) SiO2：Al2O3：(0.01-0.09)GeO2：(1-6)M：(80-300)H2O；
Carrying out hydrothermal crystallization on the obtained reaction gel, washing and drying a solid product obtained after crystallization to obtain the L-shaped molecular sieve; wherein the L-type molecular sieve has the chemical composition as follows: (0.8-1.3) M (0.001-0.007) GeO2·Al2O3·(4-7)SiO2Wherein M is K2O or is K2O and Na2A combination of O.
6. The synthesis method according to claim 5, wherein the reaction gel has a molar composition of: (10-15) SiO2：Al2O3：(0.02-0.06)GeO2：(2-6)M：(140-300)H2O。
7. The synthesis method of claim 5, wherein the L-type molecular sieve has a chemical composition of: (1.0-1.3) M (0.001-0.006) GeO2·Al2O3·(4-7)SiO2。
8. The synthetic method of claim 5, wherein the temperature of the hydrothermal crystallization is 100-200 ℃ and the time is 10-200 hours.
9. The synthesis method according to claim 5, wherein the inorganic base is potassium hydroxide or a mixture of potassium hydroxide and sodium hydroxide, the silicon source is silica sol, and the aluminum source is hydrated alumina and/or metaaluminate.
10. The method of synthesis of claim 5, wherein the Al in the structure directing agent2O3Accounting for Al in the reaction gel2O3The molar ratio of (B) is 1-5%.
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CN1055344A (en) * 1991-04-13 1991-10-16 南京大学 The prescription of L-zeolite molecular sieve guiding agent and compound method
US6607705B2 (en) * 2000-04-13 2003-08-19 Board Of Trustees Of Michigan State University Process for the preparation of molecular sieve silicas
CN101090863A (en) * 2004-12-27 2007-12-19 沙特基础工业公司 Process for making a germanium-zeolite
CN101434398A (en) * 2008-12-18 2009-05-20 南开大学 Method for synthesizing fine grain L zeolite
CN105668585A (en) * 2016-01-04 2016-06-15 北京科技大学 Methods for preparing L-type zeolite guiding agent and zeolite

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1055344A (en) * 1991-04-13 1991-10-16 南京大学 The prescription of L-zeolite molecular sieve guiding agent and compound method
US6607705B2 (en) * 2000-04-13 2003-08-19 Board Of Trustees Of Michigan State University Process for the preparation of molecular sieve silicas
CN101090863A (en) * 2004-12-27 2007-12-19 沙特基础工业公司 Process for making a germanium-zeolite
CN101434398A (en) * 2008-12-18 2009-05-20 南开大学 Method for synthesizing fine grain L zeolite
CN105668585A (en) * 2016-01-04 2016-06-15 北京科技大学 Methods for preparing L-type zeolite guiding agent and zeolite

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