KR100925851B1 - Preparation method of zeolites with high silica/alumina ratio - Google Patents

Abstract

The present invention is a zeolite precursor gel prepared by aging a solution containing a silica precursor, an alumina precursor, an organic amine template and water, and a zeolite synthetic gel in which a silica precursor insoluble in the synthetic gel is mixed in a range of 10 to 50 ℃ The present invention relates to a method for economically preparing zeolites having various Si / Al ratios, MFI or * BEA structures while significantly reducing the use of conventionally expensive organic amine templates and water.

Zeolite, Synthetic, Organoamine Template, Aging Gel

Description

Preparation method of zeolites with high silica / aluminum ratio

The present invention relates to a method for economically preparing a zeolite having an appropriate crystal size (0.05 to 5 μm) with various Si / Al ratios while minimizing the use of expensive organic amine templates and water used for the synthesis of zeolites. will be.

Zeolites with low silica content, such as zeolites A, X, Y, KL, chabazite and the like, are generally capable of synthesis without the use of organic amine templates in the synthesis. Generally, ZSM-5 or beta zeolites with high silica content can be synthesized by using organic amine templates, and organic amines under special synthesis conditions or some extremely limited Si / Al ratios. It is known that some synthesis is possible without the use of a template, but the synthesis of zeolite having a high Si / Al ratio is known to be possible only by using an organic amine template.

Organoamine templates are generally expensive and use tetrapropylammonium ions, which are expensive quaternary amines, especially in the synthesis of commercially important ZSM-5, and in the case of beta zeolites, Since the synthesis is performed using tetraethylammonium ions, the zeolite price becomes expensive.

Republic of Korea Patent Registration No. 0511638 is the activated silica by absorbing the aqueous sodium aluminate solution into the silica source that activated the inside of the pores of the porous silica carrier by treating the porous silica carrier with aqueous sodium hydroxide solution in the hydrothermal synthesis of ZSM-5 zeolite A method of synthesizing fine and uniform ZSM-5 crystal grains by allowing a circle and an alumina source to bind in pores and hydrogelize them is proposed. This suppresses the single crystal growth of ZSM-5 crystal grains trapped in the pores of the porous silica carrier and produces the ZSM-5 aggregates of the polycrystalline phase, thereby improving the yield of the ZSM-5 zeolite and improving the filtration efficiency after the preparation. The present invention describes a method for preparing an improved ZSM-5-based zeolite, but only ZSM-5 in a limited Si / Al range can be synthesized without using an organic amine template.

U.S. Patent No.7244409 describes a method for preparing zeolites having an Si / Al atomic ratio of 8 to 45 and very small primary microcrystals. The Al source and the organic template are reacted under hydrothermal conditions so that the Si / Al atomic ratio is 9-50. MFI, characterized in that the ratio between the major and minor axes of the primary microcrystals is 1.0 to 1.5: 1 and the reaction is carried out in the presence of seed crystals having an average particle size of 10 to 100 nm from the initial batch without separation from the mother liquor. A zeolite preparation having a structure is described. However, tetrapropylammonium bromide, an organic amine template, was likewise used in excess in conventional ZSM-5 preparation.

U.S. Patent No. 5783321 relates to the preparation of crystalline tetosilicate ZSM-5 zeolites comprising needle-like aggregates, using K ions to synthesize needle-type zeolites, and 1, 6-diaminohexane as organic amine template. I'm using

Republic of Korea Patent Registration No. 0173439 is 5-12 mol M2O (M is alkali metal ions or alkaline earth metal ions), 1-10 mol of tetrapropylammonium bromide (TPABr), H ₂ O 2,000- A method for synthesizing and preparing zeolites is described at a composition ratio of 5,000 mol, Al ₂ O ₃ and SiO ₂ (SiO ₂ / Al ₂ O ₃ = 25 to ∞).

Republic of Korea Patent Registration No. 0165014 relates to fibrous zeolite ZSM-5 and a method for manufacturing the same, and describes a method for producing a light-transmissive fibrous zeolite by synthesizing and drying nanometer-sized ZSM-5, Tetra of high content Propylammonium hydroxide was used as the organic amine template.

According to the present invention, when a large amount of conventional expensive organic amine template is used or the organic amine template is not used, the crystal size of the zeolite prepared by performing extremely limited synthetic conditions (Si / Al ratio, etc.) It is proposed to improve a problem that is too large to be used as a catalyst or the like. In other words, the present invention provides a method for economically preparing zeolites by minimizing the use of expensive organic amine templates for zeolites having various Si / Al ratios and suitable crystal sizes (0.05 to 5 μm).

The present invention is a step of preparing a zeolite precursor synthetic gel by aging a 1 mole of silica precursor, 0.05 to 0.5 molar ratio of organic amine template, and 5 to 200 molar ratio of water, the zeolite precursor synthetic gel prepared above, and in the first step There is a characteristic of the method for preparing zeolite comprising two steps of preparing a zeolite by hydrothermally synthesizing a zeolite synthetic gel mixed with an insoluble silica precursor in a range of 10 to 50 ℃ prepared synthetic gel.

The present invention is to prepare a zeolite by using a hydrothermal synthesis method of a zeolite precursor synthetic gel mixed with an organic amine template and water and a zeolite synthetic gel mixed with a specific silica, significantly reducing the amount of use of expensive organic amine compared to the conventional At the same time, it is possible to economically manufacture zeolites having MFI or * BEA structures with high Si / Al ratios.

In addition, since the specific silica is insoluble in the zeolite precursor synthetic gel prepared by aging, the water content of the zeolite synthesis mixture can be drastically reduced compared to the conventional method, thereby increasing the zeolite weight obtained per unit volume of the zeolite composite mixture. Therefore, high zeolite productivity can be obtained even when using a smaller reactor than the conventional zeolite synthesis reactor.

The present invention is a method for producing a zeolite using a zeolite precursor synthetic gel aged with an organic amine template and water and specific silica.

In more detail, a silica precursor is added to a basic aqueous solution containing an organic amine template and aged to form a fine zeolite precursor synthetic gel. Thereafter, a silica precursor having an insolubility in the range of 10 to 50 ° C. is added to the zeolite precursor synthetic gel to hydrothermally synthesize the gel. When the temperature is increased for the hydrothermal synthesis, zeolite crystallization occurs from the zeolite precursor synthetic gel, and at the same time, these insoluble sources start to melt and act as nutrients to the growth of the zeolite crystals. It is possible to manufacture zeolite even under the shape.

At this time, when using a silica precursor that is soluble at room temperature with respect to the aged zeolite precursor synthetic gel, the zeolite synthesis does not occur because the pH of the zeolite precursor synthetic gel is dropped while they are mixed. This is because when the silica precursor is dissolved in the basic solution, it becomes silicic ion and serves to lower the pH of the solution, which is not suitable for zeolite crystallization to occur. In other words, when the silicic ion is condensation or crystallization, the pH is increased, so that the zeolite crystallization proceeds simultaneously with the dissolution of the silica precursor having insolubility for the synthetic gel which is the silica precursor constituting the zeolite. Since the pH is almost constant during zeolite synthesis, the synthesis of zeolite is possible even in a small amount of organic amine template.

In addition, since the insoluble silica precursor is used, the synthesis is possible by using a small amount of water.

Below. Looking in more detail as a method for producing a zeolite according to the present invention.

First, a silica precursor, an organic amine template and water are mixed, and then aged to prepare a zeolite precursor synthetic gel.

The silica precursor and the organic amine template are generally used in the art and are not particularly limited. Specifically, the silica precursor may use tetraalkyl orthosilicate, silica sol, silica gel, sodium silicate, fumed silica, or mixtures thereof.

Tetraalkylammonium and tetraalkylammonium precursors may be used as the organic amine precursor. Preferably, tetraalkylammonium having an alkyl group of 1 to 6 carbon atoms may be used, using a halide of tetraalkylammonium or a hydroxide of tetraalkylammonium. It is good to use.

In general, halides of tetraalkylammonium, specifically chloride, bromide, and fluoride, are low acidity of the zeolite synthetic gel, which is not suitable for zeolite synthesis, and additionally, by adding a base such as sodium hydroxide (NaOH) or ammonia, It is desirable to control the.

The organic amine precursor is used in the range of 0.05 to 0.5 molar ratio, preferably 0.1 to 0.3 molar ratio with respect to 1 mole of the silica precursor (Si-based). If the amount is less than 0.05 molar ratio, the amount of the organic amine template is small and fine zeolite In the case where crystal formation is difficult and exceeds 0.5 molar ratio, it is preferable to maintain the above range because a problem of expensive production of zeolite due to overuse of an expensive organic amine template occurs.

In addition, water is used in a range of 5 to 200 molar ratios, preferably 10 to 100 molar ratios, per mole of the silica precursor. If the amount is less than 5 molar ratios, the silica precursor cannot be sufficiently dissolved. It is preferable to maintain the above range because a problem occurs in the formation of fine zeolite crystals due to the dilution effect of the base due to the use of excess water.

In addition, in order to introduce aluminum into the zeolite skeleton and to adjust the pH of the zeolite precursor synthetic gel to a range of 10 to 13, an aluminum precursor and an alkali metal precursor may be mixed. The aluminum precursor and the precursor of the alkali metal are generally used in the art, and are not particularly limited, and each of them may be used, or a compound containing them may be used. It is preferable to use the alkali metal precursor containing sodium ions. That is, aluminum alkoxide, sodium sulfate, sodium hydroxide, etc. may be used, respectively, or it may mix and use sodium aluminate.

The zeolite precursor synthetic gel as described above is different in type and component content of the organic amine template according to the structure of the zeolite to be prepared.

Specifically, in the case of a synthetic gel having an MFI structure, tetrapropylammonium and a precursor thereof are used as the organic amine precursor, and the component content of the synthetic gel has a Si / Al molar ratio of 10 to ∞ (consisting only of Si), preferably 30 to ∞ (consisting of Si only) range; Na / Si molar ratio is 0-0.3, Preferably it is 0-0.2; The organic amine template / Si molar ratio is 0.05 to 0.5, preferably 0.1 to 0.3; The H ₂ O / Si molar ratio is 5 to 200, preferably 15 to 100.

In case of having a beta structure, tetraethylammonium and a precursor thereof are used in the case of the synthetic gel, and the component content of the synthetic gel has a Si / Al molar ratio of 10 to ∞ (only of Si), preferably in the range of 30 to ∞. ; Na / Si molar ratio is 0-0.3, Preferably it is 0.05-0.2; The organic amine template / Si molar ratio is 0.05 to 0.5, preferably 0.1 to 0.4; The H ₂ O / Si molar ratio is 5 to 200, preferably 15 to 50.

The aging is carried out in the range of 20 to 120 ℃ to prepare a nano-sized zeolite precursor synthetic gel, when the temperature is less than 20 ℃ takes too long to form the nano zeolite, when the zeolite crystals are over 120 ℃ It is desirable to maintain this range because it grows so large that problems unsuitable for use as crystal nuclei arise.

The zeolite precursor synthetic gel prepared above maintains a molar ratio of SiO _{2 in} 1 mol: Al ₂ O ₃ 0-0.05 molar ratio: organic amine template 0.05-0.5 molar ratio: alkali metal oxide 0-0.3 molar ratio: H ₂ O 5-200 molar ratio. .

Next, a zeolite is prepared by hydrothermally synthesizing the prepared zeolite precursor synthetic gel and the zeolite synthetic gel mixed with an insoluble silica precursor in a range of 10 to 50 ° C. in the prepared zeolite precursor synthetic gel.

The hydrothermal synthesis using the insoluble silica precursor in the range of 10 to 50 ℃, preferably 10 to 30 ℃ in the zeolite precursor synthetic gel prepared by the aging is characterized in the technical configuration. That is, the silica precursor used in the zeolite precursor synthetic gel is generally used in the art and is not particularly limited, but the silica precursor mixed with the synthetic gel to perform hydrothermal synthesis is insoluble in the synthetic gel at the above temperature. Should be used only. Such insoluble silica precursors are also generally used in the art, but are not particularly limited, but silica sol, silica gel, and fumed silica or mixtures thereof may be used. In addition, although the silica precursor itself has solubility, what was converted into insoluble silica by the drying, baking, and grinding method may be used. Specifically, tetraalkyl orthosilicate cannot be used to have solubility by itself, but when it is hydrolyzed and then dried, calcined, and pulverized, it becomes insoluble silica, and thus it can be used.

In the preparation thereof, an aluminum precursor, an alkali metal precursor, and water may be mixed to additionally introduce aluminum to the zeolite or to adjust the basicity thereof. The aluminum precursor and the alkali metal precursor are the same as mentioned above. At this time, the aluminum precursor and the alkali metal precursor have a Si / Al molar ratio of 10 to ∞ (only of Si), preferably 20 to ∞; The Na / Si molar ratio is preferably 0 to 0.2, preferably used to maintain the range 0 to 0.1.

The mixing ratio of the zeolite precursor synthetic gel and the insoluble silica precursor is based on the silica content of the zeolite precursor synthetic gel relative to the insoluble silica precursor, that is, the molar ratio of the silica of the synthetic gel to 1 mol of insoluble silica is preferably in the range of 0.02 to 2 Below, it shows in the range of 0.03-1. If the molar ratio is less than 0.02 molar ratio, the relative amount of the organic amine template is too small to leave the zeolite unreacted material, and when the molar ratio exceeds 2 molar ratio, the organic amine template is drastically reduced, resulting in a problem in which the zeolite synthesis is not characteristic. Therefore, it is preferable to maintain the above range.

In this case, the zeolite synthetic gel mixed with the zeolite precursor synthetic gel and the insoluble silica precursor has a composition of 1 mol of SiO ₂ : Al ₂ O ₃ 0 to 0.05 mol ratio: Organic amine template 0.001 to 0.03 mol ratio: alkali metal oxide 0 to 0.2 The molar ratio and H ₂ O 2 to 7.4 molar ratio are maintained.

The hydrothermal reaction may be carried out under agitation or agitating conditions, and preferably, agitation is performed under agitation. The reactor is also run in a Teflon reactor or a Teflon-coated stainless steel autoclave. The reaction temperature is carried out for 1 hour to 7 days at 100 to 200 ℃, preferably 120 to 190 ℃ bar, if the temperature is less than 100 ℃ takes too long to synthesize the zeolite is produced when it exceeds 200 ℃ It is preferable to maintain the above range because a problem arises in that the size of the zeolite crystals becomes too large.

Thereafter, water washing such as filtration centrifugation and precipitation washing is performed. Specifically, the pH is neutralized with an acid to aggregate the zeolite and a small amount of unreacted particles, so that filtration or precipitation washing can be more easily washed. In addition, when the zeolite is synthesized using a small amount of water, the binder can be formed by mixing the zeolite suspension synthesized immediately without a separate washing process. The molding may then use methods commonly used in the art, such as pellets, extrusion, spray drying.

The size of the zeolite crystals prepared by the above process is maintained 0.03 ~ 10 ㎛ but there is a slight difference depending on the crystal structure. Specifically, in the case of MFI, it is in the range of 0.05 to 10 μm, preferably 0.1 to 5 μm, and the crystal has a plate or needle shape. * In the case of BEA, it represents 0.03-10 micrometers, Preferably it is 0.05-7 micrometers, and has a spherical crystal form.

Hereinafter, the present invention is described in detail in order to describe the present invention, but the present invention is not limited to the embodiments.

Example 1

To 31 g of water and 9.6 g of tetrapropylammonium hydroxide (TPAOH, 22.5% by weight), 14 g of tetraososilicate (TEOS) was mixed and stirred for 6 hours to hydrolyze TEOS and put in a closed plastic container at 90 ° C. Aging for 10 hours in an oven to prepare a zeolite synthetic gel.

Separately, 1.3 g of sodium aluminate (NaAlO ₂ , Na ₂ O = 31.0 to 35.0 wt%, Al ₂ O ₃ = 34.0 to 39.0 wt%) was dissolved in 43 g of water, and silica sol (Ludox AS-40, 40 wt%) 183 19 g of fumed silica was mixed with g, followed by stirring for 1 hour, thereby preparing a uniform silica alumina sol.

The zeolite synthetic gel and silica alumina sol were mixed and stirred for 30 minutes. At this time, the composition of the mixture was maintained in 1 mol of SiO ₂ : 0.00294 mol of Al ₂ O ₃ : 0.00333 mol of TPA ₂ O: 0.0044 mol of Na ₂ O: 6.7 mol of H ₂ O.

The mixture was transferred to an autoclave equipped with a Teflon vessel and reacted at 170 ° C. for 4 days, and the resulting product was centrifugally washed with distilled water and dried at 120 ° C.

X-ray diffraction analysis of the product obtained above is shown in (A) of FIG. The analysis was confirmed with ZSM-5 in single phase with typical MFI structure. Also, as shown in the scanning electron microscope (SEM) of FIG. 2 (A), a hexagonal plate-shaped zeolite having an average length of 0.35 μm was produced, and the BET specific surface area was 385 m ² / g.

Example 2

To 31 g of water and 9.6 g of tetrapropyl ammonium hydroxide (TPAOH, 22.5 wt%), 0.44 g of aluminum isopropoxide (IPA) was mixed and stirred until a clear solution was obtained. Thereafter, 14 g of TEOS was mixed and stirred to hydrolyze the TEOS, and then put in a sealed plastic container and aged in an oven at 90 ° C. for 10 hours to prepare a zeolite synthetic gel.

Separately, 38.4 g of water and 23.4 g of fumed silica were mixed with 94 g of silica sol (Ludox AS-40, 40 wt%), followed by stirring for 1 hour to prepare a uniform silica slurry.

The zeolite synthetic gel and the silica slurry were mixed and stirred for 30 minutes. At this time, the composition of the mixture is SiO ₂ 1 mol: Al ₂ O ₃ 0.0025 mol; 0.005 mol TPA ₂ O: 7.4 mol H ₂ O was maintained.

The mixture was transferred to an autoclave equipped with a Teflon container, and then the product obtained by reacting at 170 ° C. for 4 days was filtered washed with distilled water and dried at 120 ° C.

The obtained product was analyzed by X-ray diffraction and the results are shown in (B) of FIG. 1. The analysis identified ZSM-5 as a single phase with a typical MFI structure. Also, as shown in the scanning electron microscope (SEM) of FIG. 2 (B), a hexagonal plate-shaped zeolite having an average length of 0.35 μm was produced, and the BET specific surface area was 394 m ² / g.

Example 3

31 g of water and 9.6 g of tetrapropyl ammonium hydroxide (TPAOH, 22.5 wt%) were mixed with 9.9 g of silica sol (Ludox AS-40, 40 wt%), and then stirred in a sealed plastic container in an oven at 90 ° C. Aging for 10 hours to prepare a zeolite synthetic gel.

Separately, 2.9 g of sodium aluminate (NaAlO ₂ , Na ₂ O = 31.0 to 35.0 wt%, Al ₂ O ₃ = 34.0 to 39.0 wt%) was dissolved in 50.0 g of water, impregnated in 58.7 g of silica gel, and then dried in an oven at 120 ° C. I was. Thereafter, the dried alumina-silica was finely ground using a mortar and then mixed with 80 g of water to prepare a silica slurry.

The zeolite synthetic gel and the silica slurry were mixed and stirred for 30 minutes. At this time, the composition of the mixture is SiO ₂ 1 mol: Al ₂ O ₃ 0.02 mol; 0.005 mol TPA ₂ O: 0.03 mol Na ₂ O; 6.2 moles of H ₂ O were maintained.

The mixture was transferred to an autoclave equipped with a Teflon vessel and reacted at 170 ° C. for 4 days, and the product obtained by filtration and washing with distilled water was dried at 120 ° C.

The obtained product was analyzed by X-ray diffraction and the results are shown in (C) of FIG. 1. The analysis identified ZSM-5 as a single phase with a typical MFI structure. Also, as shown in the scanning electron microscope (SEM) of FIG. 2C, a hexagonal plate-shaped zeolite having an average length of 0.4 μm was produced, and the BET specific surface area was 405 m ² / g.

Example 4

To a solution of 31 g of water and 8 g of tetraethylammonium hydroxide (TEAOH, 35% by weight) and 9.5 g of silica sol (Ludox AS-40, 40% by weight) was mixed, 0.17 g of sodium aluminate was added to 5.7 g of water. After the solution dissolved in, was added to a sealed plastic container and aged in an oven at 90 ℃ for 10 hours to prepare a zeolite synthetic gel.

Separately, 2.2 g of sodium aluminate (NaAlO ₂ , Na ₂ O = 31.0 to 35.0 wt%, Al ₂ O ₃ = 34.0 to 39.0 wt%) was dissolved in 50.0 g of water, 1.27 g of caustic soda in 35 g of water, and then silica gel. It was impregnated to 49.9 g and then dried in an oven at 120 ° C. Thereafter, the dried alumina-silica was finely ground using a mortar and then mixed with 80 g of water to prepare a silica slurry.

The zeolite synthetic gel and the silica slurry were mixed and stirred for 30 minutes. At this time, the composition of the mixture is SiO ₂ 1 mol: Al ₂ O ₃ 0.01 mol: TEA ₂ O 0.011 mol: Na ₂ O 0.034 mol; H ₂ O 4 mol was maintained.

The mixture was transferred to an autoclave equipped with a Teflon vessel and reacted at 170 ° C. for 4 days, and the product obtained by filtration and washing with distilled water was dried at 120 ° C.

X-ray diffraction analysis of the product obtained above is shown in (D) of FIG. The analysis confirmed a beta phase of a single phase with a typical * BEA structure. In addition, as shown in the scanning electron microscope (SEM) of FIG. 2 (D), the microparticles having a length of about 0.05 μm were mixed with the particles having a size of about 5 μm, and the BET specific surface area was 485 m ² /. g.

Comparative Example 1

Zeolite was prepared without preparing a zeolite synthetic gel.

To a solution of 60 g of water and 9.6 g of tetrapropyl ammonium hydroxide (TPAOH, 22.5% by weight) was added 63.9 g of silica sol (Ludox AS-40, 40% by weight) with stirring, and fumed silica (fumed) 13.5 g of silica) was added thereto, followed by stirring for 1 hour to prepare a uniform zeolite synthetic gel having the following molar composition. At this time, the composition of the mixture maintained 1 mol of SiO ₂ : 0.0083 mol of TPA ₂ O: 5.9 mol of H ₂ O.

The mixture was transferred to an autoclave equipped with a Teflon vessel and reacted at 170 ° C. for 4 days, and the product obtained by filtration and washing with distilled water was dried at 120 ° C.

X-ray diffraction analysis of the product obtained above is shown in (E) of FIG. As a result of the analysis, a weak diffraction pattern of single-phase silicalite (silicalite) having an MFI structure was obtained, and it was confirmed that there was a wide peak corresponding to amorphous silica at around 2θ = 24 °. Also, as shown in the scanning electron microscope (SEM) of FIG. 2 (E), a long rod-shaped large crystal zeolite having an average length of 40 μm, an average width of 13 μm, and an average thickness of 10 μm was formed, and added as a reactant. It was confirmed that most of the silica was obtained as an unreacted material and covered the zeolite crystal surface, and the BET specific surface area of the sample was 235 m ² / g.

Comparative Example 2

Alumina-silica slurries were performed using silicic acid, which was soluble in zeolite synthetic precursors at room temperature.

Tetraosilicate was added to 31 g of water and 9.6 g of tetrapropyl ammonium hydroxide (TPAOH, 22.5% by weight), 0.44 g of aluminum isopropoxide (IPA), and stirred until a clear solution was obtained. (TEOS) 14 g of the mixture was stirred for 6 hours to hydrolyze TEOS, and then put in a sealed plastic container and aged for 10 hours in a 90 ℃ oven to prepare a zeolite synthetic gel.

Separately dissolve 15.4 g of sodium silicate (Na ₂ SiO ₃ , SiO ₂ 36.6 wt%, Na / Si = 0.9 molar ratio) in 52 g of water, and add 40 g of silica sol (Ludox AS-40, 40 wt%) to this solution. Was added and heated at 95 ° C. for 10 hours to prepare a solution in which the silica component of the silica sol was dissolved.

The zeolite synthetic gel and the solution in which the silica component was dissolved were mixed and stirred for 30 minutes. At this time, the composition of the mixture is SiO ₂ 1 mol: TPA ₂ O 0.0125 mol: Na ₂ O 0.105 mol; 15.9 mol of H ₂ O was maintained.

The mixture was transferred to an autoclave equipped with a Teflon vessel and reacted at 170 ° C. for 4 days, and the product obtained by filtration and washing with distilled water was dried at 120 ° C.

The obtained product was analyzed by X-ray diffraction and the results are shown in (F) of FIG. 1. As a result of the analysis, a very weak diffraction pattern of single-phase silicalite (silicalite) having an MFI structure was obtained, and it was confirmed that there was a wide peak corresponding to amorphous silica in the vicinity of 2θ = 24 °. In addition, as shown in the scanning electron microscope (SEM) of Figure 2 (F) consists of unreacted microparticles and the BET specific surface area was 198 m ² / g.

Figure 1 shows the X-ray diffraction pattern (XRD) of the zeolites prepared in Examples 1 to 4 and Comparative Examples 1 to 2 according to the present invention, Example 1 (A), Example 2 (B) , Example 3 (C), Example 4 (D), Comparative Example 1 (E), and Comparative Example 2 (F).

Figure 2 shows an electron microscope (SEM) photograph of the zeolite prepared in Examples 1 to 4 and Comparative Examples 1 to 2 according to the present invention, Example 1 (A), Example 2 (B), Examples 3 (C), Example 4 (D), Comparative Example 1 (E), and Comparative Example 2 (F).

Claims (9)

1 step of preparing a zeolite precursor synthetic gel by ripening 1 mole of silica precursor, 0.05 to 0.5 mole ratio of organic amine template, and 5 to 200 mole ratio of water; The zeolite precursor synthetic gel prepared above and the silica precursor insoluble in the range of 10 to 50 ° C. are mixed with the synthetic gel prepared in the first step, so that a SiO ₂ 1 mol: organic amine template 0.001 to 0.03 molar ratio: H ₂ O 2 to 7.4 Step 2 to prepare zeolite by hydrothermal synthesis of zeolite synthetic gel in the molar ratio range Method for producing a zeolite having an MFI or * BEA structure, characterized in that it comprises a crystal size of 0.03 ㎛ to 10 ㎛ range. The method according to claim 1, wherein an aluminum precursor and an alkali metal precursor are further contained in each of the silica precursors of the first and second steps. The method of claim 1, wherein the silica precursor of the second step is a single compound or a mixture of two or more selected from silica, silica sol, silica gel, and fumed silica. The method of claim 1, wherein the organic amine template is a tetraalkylammonium or a tetraalkyl ammonium precursor. The method of claim 1, wherein the one-step aging is carried out in the range of 20 to 120 ℃. The method of claim 1, wherein the two-stage hydrothermal synthesis is performed at 100 to 200 ° C. for 1 hour to 7 days. According to claim 2, wherein the aged zeolite synthetic gel of step 1 SiO ₂ 1 moles: Al ₂ O ₃ 0 ~ 0.05 molar ratio of organic amine primary clamping 0.05 to 0.5 mole ratio of alkali metal oxide, 0 to 0.3 mole ratio, the manufacturing method characterized by maintaining the molar ratio H ₂ O 5 ~ 200. The zeolite synthetic gel of claim 2, wherein the zeolite synthetic gel of step 2 comprises: SiO ₂ 1 mol: Al ₂ O ₃ 0-0.05 molar ratio: Organic amine template 0.001-0.03 molar ratio: Alkali metal oxide 0-0.2 molar ratio, H ₂ O 2- 7.4 A process characterized by maintaining the molar ratio. delete

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