CN110550641A - 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 PDFInfo
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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 molar composition of the structure directing agent is (6-20) M, Al 2 O 3, (0.1-1.8) GeO 2, (8-25) SiO 2, (150-500) H 2 O, and M in the formula is K 2 O or the combination of K 2 O and Na 2 O.
Description
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，
In the formula, M is a metal ion, the most main metal ion is K +, and can be replaced by other alkali or alkaline earth metal ions, but in general, more than 90% of K + in L zeolite is not easy to be exchanged, n is the valence number 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 (6-20) M, Al 2 O 3, (0.1-1.8) GeO 2, (8-25) SiO 2, (150-500) H 2 O, wherein M is K 2 O or the combination of K 2 O and Na 2 O.
Preferably, the molar composition of the structure-directing agent is (6-12) M, Al 2 O 3, (0.2-1.2) GeO 2, (8-20) SiO 2, (200-400) H 2 O.
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, the inorganic base, the aluminum source, the silicon source and water to obtain reaction gel, wherein the molar composition of the reaction gel is (6-20) SiO 2, (0.01-0.09) GeO 2, (1-6) M, (80-300) H 2 O, (10-15) SiO 2, (0.02-0.06) Al 2 O 3, (2-6) M, (140-300) H 2 O;
And (3) carrying out hydrothermal crystallization on the obtained reaction gel, washing and drying a solid product obtained after crystallization to obtain the L-type molecular sieve, wherein the chemical composition of the L-type molecular sieve is (0.8-1.3) M (0.001-0.007) GeO 2 Al 2 O 3 (4-7) SiO 2, preferably (1.0-1.3) M (0.001-0.006) GeO 2 Al 2 O 3 (4-7) SiO 2.
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% by mass, preferably 25 to 40% by mass, the aluminum source may be hydrated alumina and/or metaaluminate, and the metaaluminate may be potassium metaaluminate and/or sodium metaaluminate, the molar ratio of Al 2 O 3 in the structure directing agent to Al 2 O 3 in the reaction gel 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 steps of contacting an aromatization raw material with the L-shaped molecular sieve loaded with platinum provided by the invention and carrying out aromatization reaction under the hydrogen condition, wherein the aromatization raw material can be alkane of C 6 -C 7, preferably straight-chain alkane of C 6 -C 7, the temperature of the aromatization reaction can be 550 ℃, the pressure can be 0.5-2 MPa, the volume space velocity of a feeding liquid can be 1-5h -1, and the volume ratio of hydrogen to hydrocarbon can be (500-.
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 formula of the molar composition of a feed mixture of 8K 2 O.Al 2 O 3. GeO 2.14 SiO 2.320H 2 O, 4.31g of GeO 2 and 6g of hydrated alumina (the content of alumina is 70 mass percent, the same applies below) are added into 168.51g of solution containing 36.89g of KOH, the mixture is heated and dissolved to obtain a mixed solution, 138.35g of silica sol (containing 25 mass percent of SiO 2 and having the pH value of 9 and the same applies below) is added into the mixed solution preheated to 50 ℃ under stirring, the mixture is stirred for 0.5 hour to form a reaction gel, and the reaction gel is aged at 34 ℃ for 72 hours to obtain a translucent sol serving 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 formula of the molar composition of a feeding mixture of 8K 2 O.Al 2 O 3.0.6 GeO 2.14 SiO 2.320H 2 O, 2.58g GeO 2 and 6g hydrated alumina are added into 168.51g solution containing 36.89g KOH, heated and dissolved to obtain mixed solution, the mixed solution is added into 138.35g silica sol preheated to 50 ℃ under stirring to form reaction gel after 0.5 hour of stirring, and the reaction gel is aged at 34 ℃ for 72 hours to obtain semitransparent sol serving 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 is added into 43.31g of a solution containing 9.97g of KOH, the mixture is heated and dissolved to obtain a mixed solution, the mixed solution is added into 81.52g of silica sol under stirring, 8.19g of the structure directing agent prepared in example 1 is added, and the reaction gel is formed by stirring for 0.5 hour, wherein the molar composition of the reaction gel is 10SiO 2. Al 2 O 3.0.03 GeO 2.2.75K 2 O.160H 2 O, and the molar ratio of Al 2 O 3 in the structure directing agent to Al 2 O 3 in the reaction gel is 3.0 percent.
And transferring the reaction gel into a reaction kettle, crystallizing at 170 ℃ for 48 hours, rapidly cooling to 40 ℃, centrifugally separating and washing the 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-1, wherein the 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 1.02K 2 O.0.003 GeO 2. Al 2 O 3.5.28 SiO 2.
Example 5
The structure directing agent prepared in example 2 was used to synthesize the L-type molecular sieve.
2.95g of hydrated alumina is added into 24.25g of a solution containing 5.60g of KOH, the mixture is heated and dissolved to obtain a mixed solution, the mixed solution is added into 47.48g of silica sol under stirring, 8.19g of the structure directing agent prepared in example 2 is added, and the reaction gel is formed by stirring for 0.5 hour, wherein the molar composition of the reaction gel is 10SiO 2. Al 2 O 3.0.05 GeO 2.2.75K 2 O.160H 2 O, and the molar ratio of Al 2 O 3 in the structure directing agent to Al 2 O 3 in the reaction gel is 5.0 percent.
And transferring the reaction gel into a reaction kettle, crystallizing at 170 ℃ for 48 hours, 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 0.98K 2 O.0.004 GeO 2. Al 2 O 3.5.01 SiO 2.
Example 6
The structure directing agent prepared in example 3 was used to synthesize the L-type molecular sieve.
3.72g of hydrated alumina is added into 31.40g of a solution containing 7.24g of KOH, the mixture is heated and dissolved to obtain a mixed solution, the mixed solution is added into 60.25g of silica sol under stirring, 8.15g of the structure directing agent prepared in example 3 is added, and the reaction gel is formed by stirring for 0.5 hour, wherein the molar composition of the reaction gel is 10SiO 2. Al 2 O 3. 0.024GeO 2. 2.75K 2 O.160H 2 O, and the molar ratio of Al 2 O 3 in the structure directing agent to Al 2 O 3 in the reaction gel is 4.0 percent.
And transferring the reaction gel into a reaction kettle, crystallizing at 170 ℃ for 48 hours, 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-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 1.05K 2 O.0.002 GeO 2. Al 2 O 3.5.75 SiO 2.
Comparative example 1
Preparing the germanium-free L-type molecular sieve.
According to the formula of the molar composition of a feeding mixture of 8K 2 O.Al 2 O 3.14 SiO 2.320H 2 O, 6g of hydrated alumina is added into 132g of solution containing 36.89g of KOH, the solution is heated and dissolved to obtain a mixed solution, the mixed solution is added into 138g of silica sol preheated to 50 ℃ under stirring to form a reaction gel after 0.5 hour of stirring, and the reaction gel is aged at 34 ℃ for 72 hours to obtain a translucent sol serving as a guiding agent.
Adding 5.01g of hydrated alumina into 43.31g of solution containing 9.97g of KOH, heating and dissolving to obtain a mixed solution, adding the mixed solution into 81.52mL of silica sol while stirring, adding 8.08g of the guiding agent, and stirring for 0.5 hour to form a reaction gel, wherein the molar composition of the reaction gel is 10SiO 2. Al 2 O 3.2.75K 2 O160H 2 O, and the molar ratio of Al 2 O 3 in the guiding agent to Al 2 O 3 in the reaction gel is 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 1.16K 2 O.Al 2 O 3.6.44 SiO 2.
Comparative example 2
According to the formula that the molar composition of a feeding mixture is 8K 2 O.Al 2 O 3.2 GeO 2.14 SiO 2.320H 2 O, 8.61g GeO 2 and 6g hydrated alumina are added into 168.51g solution containing 36.89g KOH, heated and dissolved to obtain mixed solution, the mixed solution is added into 138.35g silica sol preheated to 50 ℃ under stirring, reaction gel is formed after stirring for 0.5 hour, the reaction gel is aged at 34 ℃ for 72 hours to obtain translucent sol, and the high-germanium structure directing agent is obtained.
Adding 2.95g of hydrated alumina into 24.25g of a solution containing 5.60g of KOH, heating and dissolving to obtain a mixed solution, adding the mixed solution into 47.48g of silica sol while stirring, adding 8.30g of the high germanium structure directing agent prepared in the comparative example, wherein the molar ratio of Al 2 O 3 in the directing agent to Al 2 O 3 in the reaction gel is 5.0%, and stirring for 0.5 hour to form the reaction gel, wherein the molar composition of the reaction gel is 10SiO 2. Al 2 O 3. 0.1GeO 2. 2.75K 2 O.160H 2 O.
and (3) transferring the reaction gel into a reaction kettle, crystallizing at 170 ℃ for 48 hours, then quickly cooling to 40 ℃, centrifugally separating and washing the product until the pH value of a liquid phase is 10-11, and drying the obtained solid at 120 ℃ for 10 hours to obtain the germanium-containing L-type molecular sieve raw powder DGL-1 with the relative crystallinity of 67 percent, wherein the chemical composition of the molecular sieve is 1.18K 2 O0.008 GeO 2 Al 2 O 3.6.05 SiO 2.
Comparative example 3
Using the structure directing agent prepared in comparative example 1, the germanium-containing L-type molecular sieve DGL-2 was synthesized according to the synthesis recipe 10SiO 2. Al 2 O 3. 0.024GeO 2. 2.75K 2. O160H 2 O in example 6, and germanium dioxide was added to the KOH solution, the relative crystallinity was 108%, the chemical composition of the molecular sieve was 1.2K 2 O. 0.001GeO 2. Al 2 O 3. 5.21SiO 2, and the SEM picture thereof is shown in FIG. 5.
Comparative example 4
Using the structure directing agent prepared in comparative example 1, according to the synthesis formula 10SiO 2 · Al 2 O 3 · 0.05GeO 2 · 2.75K 2 O · 160H 2 O in example 5, 5.01g of hydrated alumina is added to 43.50g of a solution containing 9.97g koh and 0.19g GeO 2, heated and dissolved to obtain a mixed solution, the mixed solution is added to 81.52g of silica sol with stirring, 8.08g of the directing agent prepared in comparative example 1 is added, the molar ratio of Al 2 O 3 in the structure directing agent to Al 2 O 3 in the reaction gel is 3.0%, the reaction gel is formed with stirring for 0.5 hour, the reaction gel is transferred to a reaction kettle to crystallize at 170 ℃ for 72 hours, then rapidly cooled to 40 ℃, the product is centrifuged and washed to a liquid phase pH value of 10-11, the obtained solid is dried at 120 ℃ for 10 hours, the germanium-containing L-type molecular sieve L-3 is synthesized, the relative crystallinity is 002%, the chemical dgo group of the molecular sieve is shown in fig. 7 · 896, 7.7, 7.
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.
5g of the germanium-containing L-type molecular sieve prepared by the invention is taken as a carrier, and is respectively supersaturated and impregnated with 16mg/mL Pt (NH 3) 2 Cl 2 solution, the liquid/solid volume ratio is 4: 1 during impregnation, the impregnated solid is dried for 12 hours at 120 ℃, and is roasted for 4 hours at 350 ℃, so that a catalyst with the Pt content of 1.0 mass percent is prepared, and the serial number of the catalyst in each example, the platinum and germanium contents of the molecular sieve carrier and the catalyst are shown in Table 1.
2.5mL of catalyst is filled in 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, the hourly space velocity of a feeding liquid is 3h -1, and the volume ratio of hydrogen to hydrocarbon is 1200: 1, and 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 L-type molecular sieve raw powder L-1 synthesized in comparative example 1 was used as a carrier, and impregnated with a Pt (NH 3) 2 Cl 2 solution at a concentration of 16mg/mL and an alkaline solution containing GeO 2 at a liquid/solid volume ratio of 4: 1, and the impregnated solid was dried at 120 ℃ for 12 hours and calcined at 350 ℃ for 4 hours to prepare a catalyst DC-5 having a Pt content of 1.0 mass% and a Ge content of 0.05 mass%.
2.5mL of catalyst is filled in 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, the hourly space velocity of a feeding liquid is 3h -1, and the volume ratio of hydrogen to hydrocarbon is 1200: 1, and the results are shown in Table 1.
TABLE 1
Claims (10)
1. A structure-directing agent for synthesizing the L-type molecular sieve containing Ge has the mole composition of (6-20) M Al 2 O 3, (0.1-1.8) GeO 2, (8-25) SiO 2, (150-500) H 2 O, where M is K 2 O or the combination of K 2 O and Na 2 O.
2. The structure-directing agent as claimed in claim 1, wherein the molar composition of the structure-directing agent is (6-12) M: Al 2 O 3 (0.2-1.2) GeO 2 (8-20) SiO 2 (200-400) H 2 O.
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, the inorganic base, the aluminum source, the silicon source and the water according to claim 1 or 2 to obtain reaction gel, wherein the molar composition of the reaction gel is (6-20) SiO 2: Al 2 O 3 (0.01-0.09) GeO 2 (1-6) M (80-300) H 2 O;
And carrying out hydrothermal crystallization on the obtained reaction gel, washing and drying a solid product obtained after crystallization to obtain the L-type molecular sieve, wherein the chemical composition of the L-type molecular sieve is (0.8-1.3) M (0.001-0.007) GeO 2 Al 2 O 3 (4-7) SiO 2, wherein M is K 2 O or the combination of K 2 O and Na 2 O.
6. The synthesis method of claim 5, wherein the molar composition of the reaction gel is (10-15) SiO 2: Al 2 O 3, (0.02-0.06) GeO 2, (2-6) M (140) -300) H 2 O.
7. The synthesis method of claim 5, wherein the chemical composition of the L-type molecular sieve is (1.0-1.3) M (0.001-0.006) GeO 2 -Al 2 O 3 - (4-7) SiO 2.
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 synthesis method of claim 5, wherein the molar ratio of Al 2 O 3 in the structure directing agent to Al 2 O 3 in the reaction gel is 1-5%.
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Citations (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 |
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Patent Citations (5)
| 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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