KR101679793B1 - Porous zeolite contained iron manufacturing method and porous zeolite manufactured by the same - Google Patents

Abstract

According to the present invention, a preparation method of porous zeolite containing an iron component is a hydrothermal synthesis method via a sol-gel method. The preparation method comprises a step of synthesizing an iron component to a zeolite framework using ammonium iron citrate which is a type of organic iron complex compound and is an iron-component raw material substance. As an organic support to secure porosity of zeolite, tertbutyl alcohol, an ammonia-based organic synthetic substance, and an amine-based organic synthetic substance, or the like, is used.

Description

TECHNICAL FIELD [0001] The present invention relates to a porous zeolite containing iron component and a porous zeolite produced by the same,

The present invention relates to a process for producing an iron-containing porous zeolite and a porous zeolite produced by the process, and more particularly to a zeolite having an iron-containing raw material which is synthesized on the skeleton of a zeolite by using an organic iron complex, The present invention relates to a method for producing an iron-containing porous zeolite which forms porosity using an ammonia-based organic synthesis material or an amine-based organic synthesis material, and a porous zeolite produced thereby.

Zeolites, which are porous crystals with micropores smaller than nanometer size, are aluminosilicate silicates and are representative nanostructures widely used in a wide range of applications such as adsorbents, desiccants, ion exchangers, separating agents and catalysts.

The chemical composition of zeolite is a generic term for hydrous aluminosilicates containing metal oxides such as sodium (Na), potassium (K) and calcium (Ca), and the general formula is MeO (metal oxide) · Al ₂ O ₃ · xSiO ₂ · yH ₂ O represents a.

A common feature is that a part of the Si of the silicate (SiO ₄ -4) structure is replaced by Al to form the framework of the aluminosilicate condensed silicate and the water in the crystal structure is desorbed to form a void channel So that it has a porous structure of microscopic pores that can be made in all directions.

Recently, in order to use a porous micropore as a chemical reactor, a so-called nanoreactor, an iron compound such as FeCl ₃ , FeSO ₄ or Zero Iron as an iron salt in the process of synthesizing a zeolite using a Sol-Gel hydrothermal method Or by adding a dipping iron component to the iron salt solution after synthesizing zeolite.

In order to stably maintain the skeleton of aluminosilicate and secure porosity, ammonium ion is contained as a cation organic template in order to perform an electrical neutralization reaction with a negative silicate (SiO ₄ -4) Trialkylamines including tetra-propyl ammonium hydroxide (TPAOH), tetra-butyl ammonium hydroxide (TBAOH), tetra-ethyl ammonium hydroxide (TEAOH), tetramethyl ammonium hydroxide (TMAOH) Dialkylamines, and monoalkylamines are used.

However, when hydrothermally synthesizing zeolite by the sol-gel method, it is necessary to maintain the pH of the mixed solution at 10 or more in a high alkaline condition. In the high alkali condition, iron ions (Fe ++, Fe +++ ) And a hydroxyl group (OH-) form an insoluble iron oxyfluoride (floc) such as Fe (OH) ₂ or Fe (OH) ₃ .

Due to the formation of flocs, it is not only difficult to synthesize iron ions to the zeolite skeleton, but also lowers the formation of porosity, resulting in a decrease in specific surface area (m ² / g).

In addition, when the zeolite is dipped in the iron salt solution of the acid salt to coat the iron component with the zeolite prepared by the sol-gel method, the chemical structure of the zeolite, which is the crystal of the aluminosilicate, is impaired due to the low pH.

In the case of a cationic organic support containing an ammonium or amine group for securing the porosity of aluminosilicate and maintaining the skeleton, the price per unit g is not only high but also maintains a stable crystalline structure due to a competitive reaction with iron ions There is a difficult problem.

Korean Patent No. 10-0857352

It is an object of the present invention to provide a process for hydrothermal synthesis of a zeolite by sol-gel process, which comprises reacting zeolite with an iron ingredient material which does not form flocs by iron ion under high alkali conditions .

Another object of the present invention is to provide a method for producing zeolite which is low in cost and excellent in porosity as an organic support for directly reacting iron ions with the skeleton of aluminosilicate as a cationic agent and ensuring porosity.

According to another aspect of the present invention, there is provided a method of preparing zeolite by hydrothermal synthesis by a sol-gel method, comprising the steps of: preparing an organic iron complex compound It is preferable to prepare a zeolite.

The organic iron complex compound of the present invention is preferably ammonium iron citrate (C ₆ H ₈ O ₇ FeNH ₃ , hereinafter referred to as "AIC").

The method for producing an iron component-containing porous zeolite of the present invention is preferably an organic support for securing the porosity of zeolite using any one of tertiary butyl alcohol, ammonia organic synthesis material and amine organic synthesis material.

(S100) a raw material mixture preparation step of mixing the raw material of the zeolite of the present invention and the ammonia iron citrate (AIC) at a predetermined ratio; Aging a mixed solution for aging the raw material mixture with a mixed solution in a gel state (S200); A hydrothermal synthesis step (S300) of hydrothermally synthesizing the aged mixed solution at a certain temperature in an autoclave (S300), and a finishing step (S400) in which the hydrothermally synthesized sample is washed and filtered and dried at a predetermined temperature .

Raw material mixture of the present invention manufacturing step (S100) is the molar ratio in the raw material mixture Al ₂ O _3: SiO ₂ : Fe in the AIC = 1: 1 to 50: 0.1 to 1.

In the mixing solution aging step (S200) of the present invention, it is preferable that the raw material mixture is aged for 20 to 30 hours while stirring at a temperature of 45 ° C to 55 ° C to form a gel state.

In the hydrothermal synthesis step (S300) of the present invention, the aged mixture is preferably hydrothermally synthesized in an autoclave at 100 ° C to 180 ° C for 40 to 50 hours.

The finishing step (S400) of the present invention is preferably carried out at a temperature of 100 캜.

In the method for producing an iron component-containing porous zeolite of the present invention, the raw material of zeolite, the ammonium iron cationate and the organic support are mixed at a predetermined ratio, and the molar ratio in the raw material mixture is Al ₂ O ₃ : SiO ₂ (S100) for mixing Fe: organic support in AIC = 1: 1 to 50: 0.1 to 1: 1.5; Aging the raw material mixture solution to aging the raw material mixture solution at a temperature of 45 ° C to 55 ° C for 20 to 30 hours so as to agitate the raw material mixture solution in a gel state; A hydrothermal synthesis step (S300) of hydrothermally synthesizing the aged mixed solution in an autoclave at 100 ° C. to 180 ° C. for 40 to 50 hours; and a hydrothermal synthesis step (S300) of subjecting the hydrothermally synthesized sample to washing and filtering at a constant temperature And a finishing step (S400).

The organic support of the present invention is preferably TBA (tertiary buthyl alcohol), and is preferably dried at a temperature of 100 ° C in the finishing step.

The organic support of the present invention is preferably tetra-propyl ammonium hydroxide (TPAOH), and is preferably dried at 550 ° C in the finishing step.

The iron component-containing porous zeolite of the present invention is preferably produced by the above-described method for producing an iron component-containing porous zeolite.

According to the process for producing an iron-containing porous zeolite according to the present invention and the porous zeolite produced by the method, the iron ion can be directly reacted with the skeleton of the aluminosilicate using ammonium iron cationate as an organic iron complex, So that even when the iron content is high, there is an advantage that it can be reused repeatedly without reducing ion exchange and adsorption ability.

In addition, it is possible to have higher porosity characteristics than conventional ones by containing iron ions in the skeleton of aluminosilicate and forming a porosity in the zeolite by using low-cost TBA, And an advantage of being able to reduce manufacturing cost by using an inexpensive organic support is of course advantageous.

FIG. 1 is an electron microscope (SEM) image and an EDX mapping image of a zeolite surface prepared by the present invention.
FIG. 2 is a graph showing the binding energy of the zeolite prepared according to the present invention by analyzing binding energy using conventional zeolite, iron salt, and XPS.
3 is a graph comparing the specific surface area and pore volume of zeolite prepared using TPAOH and TBM as an organic support in the present invention.
FIGS. 4A to 4C are graphs showing the removal efficiencies of BTEX volatile materials for the conventional zeolite, the zeolite using the iron salt, and the zeolite prepared according to the present invention, respectively.

The description of the present invention is merely an example for structural or functional explanation, and the scope of the present invention should not be construed as being limited by the embodiments described in the text. That is, the embodiments are to be construed as being variously embodied and having various forms, so that the scope of the present invention should be understood to include equivalents capable of realizing technical ideas. Also, the purpose or effect of the present invention should not be construed as limiting the scope of the present invention, since it does not mean that a specific embodiment should include all or only such effect.

Meanwhile, the meaning of the terms described in the present application should be understood as follows.

The terms "first "," second ", and the like are intended to distinguish one element from another, and the scope of the right should not be limited by these terms. For example, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

It is to be understood that when an element is referred to as being "connected" to another element, it may be directly connected to the other element, but there may be other elements in between. On the other hand, when an element is referred to as being "directly connected" to another element, it should be understood that there are no other elements in between. On the other hand, other expressions that describe the relationship between components, such as "between" and "between" or "neighboring to" and "directly adjacent to" should be interpreted as well.

It is to be understood that the singular " include " or "have" are to be construed as including the stated feature, number, step, operation, It is to be understood that the combination is intended to specify that it does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

In each step, the identification code (e.g., a, b, c, etc.) is used for convenience of explanation, the identification code does not describe the order of each step, Unless otherwise stated, it may occur differently from the stated order. That is, each step may occur in the same order as described, may be performed substantially concurrently, or may be performed in reverse order.

All terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used predefined terms should be interpreted to be consistent with the meanings in the context of the related art and can not be interpreted as having ideal or overly formal meaning unless explicitly defined in the present application.

The zeolite produced according to the present invention is widely used as an ion exchanger and a catalyst, and is manufactured to bind an iron component to a skeleton of a zeolite and ensure high porosity by using a volatile organic support having a high volatility.

Components of conventional zeolite is prepared by _{NaO · Al 2 O 3 · xSiO} 2 · yH composed of chemical substances, such as ₂ or more O and 100 ℃ high temperature atmosphere at a high alkaline pH 10 or more, hydrothermal synthesis at high pressure.

In the conventional method of synthesizing zeolite, when an iron component is contained, if an iron ion-exchange method or an iron salt is directly used as a raw material, a conventional iron salt (Fe ₂ (SO ₄ ) ₃ , FeCl ₃ , Fe (NO ₃ ) ₂ ) reacts first with hydroxyl groups to form an insoluble iron-oxide precipitate, which makes it difficult for the iron component to bond to the skeleton of the zeolite, and the reaction with the aluminosilicate skeleton due to preferential reaction with hydroxyl groups Therefore, it is inevitable to reduce the ion exchange capacity and adsorption ability in the water treatment and to use it as a disposable one.

Therefore, in the present invention, by using an organic iron complex, which is a kind of chelate compound, as an iron ingredient material, it is synthesized on the skeleton of a zeolite so that the iron content can be reused repeatedly without decreasing ion exchange and adsorption ability. The organic iron complex is used to contain iron in the skeleton and the tertiary butyl alcohol to form a high porosity. Thus, in the air pollution, the adsorbing ability of volatile substances and the oxidizing function by Fenton's oxidation can be obtained.

The process for producing an iron-containing porous zeolite according to the present invention uses ammonium iron citrate (C ₆ H ₈ O ₇ FeNH ₃ , hereinafter referred to as "AIC"), which is an organic iron complex, as an iron ingredient material Butanol (TBA), which is highly soluble in water and has excellent volatility, as an organic support, and ammonia-based organic synthesis (hereinafter referred to as "TBA"), Materials, or amine-based organic synthetic materials.

Conventional zeolite synthesis is produced by a hydrothermal synthesis method under high temperature and high pressure conditions by sol-gel. In the present invention, Na ₂ SiO ₃ , NaAl ₂ O ₃ , or NaOH is used as the main raw material for synthesis of aluminosilicate Respectively.

In the present invention, in order to synthesize a zeolite containing an iron component, AIC, which is an organic iron complex, is used as an iron component raw material. In general, the organic iron complex containing iron is rich in ammonium iron citrate (AIC), iron citrate, and iron acetylacetonate. However, only AIC dissolves in water to form OH groups and iron oxides in alkaline solutions forming the Fe ⁺⁺⁺ in the positive charge to combine chemically with the (SiO ₄₎ ^-4 a negative charge to form the backbone of the aluminosilicate.

TBA for forming and maintaining porosity in zeolite is dissolved in 100% water at room temperature, and the volatilization temperature is as low as about 80 ° C. In the alkaline condition, TBA reacts with Na ⁺ to form metal alkoxide (t-BuONa, sodium tertialry butoxide.

Hereinafter, a method for producing an iron component-containing porous zeolite according to the present invention will be described in detail.

A manufacturing method according to the first embodiment of the present invention relates to a method of manufacturing a zeolite containing an iron component.

First, in order to synthesize a zeolite whose chemical components are SiO ₂ , Al ₂ O ₃ , Na ₂ O and H ₂ O, Al ₂ O ₃ and SiO ₂ , which are main raw materials, are mixed at a predetermined mixing ratio, AIC are mixed at a predetermined mixing ratio to prepare a raw material mixture liquid (S100).

At this time, SiO ₂ is in a range of 2 to 50 mol based on 1 mol of Al ₂ O ₃ in the raw material mixture, and the molar ratio of the iron component is in the range of 0.1 mol to 1 mol as the molar ratio of SiO ₂ increases (However, based on 1 mole of Al ₂ O ₃ as the main raw material, 1.5 to 3 moles of Na ₂ O and 400 to 1000 moles of H ₂ O are blended, but since they are not main raw materials, Omitted).

To summarize, the molar ratio in the raw material mixture solution is Al ₂ O ₃ : SiO ₂ : Fe in the AIC = 1: 1 to 50: 0.1 to 1 (where Fe in the AIC is defined as the molar ratio of Fe remaining in the AIC since the Fe concentrations in the AIC are different depending on the solubility and other conditions).

When the raw material mixture preparation step (S100) is completed, a mixed solution aging step (S200) is performed for aging the raw material mixture solution in a sol state into a gel mixture solution. The aging of the mixed solution is performed in a gel state by stirring the raw material mixture in a sol state at a temperature of 45 ° C to 55 ° C, preferably 50 ° C, for 20 hours to 30 hours, preferably aging for 24 hours.

The aged mixture is subjected to a hydrothermal synthesis step (S300) in an autoclave at about 100 ° C to 180 ° C for 40 to 50 hours, preferably 48 hours for hydrothermal synthesis.

The hydrothermally synthesized sample may be made into a final zeolite by a cleaning step (S400) in which the sample is washed and filtered and then dried at about 100 ° C.

A method of manufacturing a porous zeolite containing an iron component according to a second embodiment of the present invention.

The production method according to the second embodiment is for preparing a porous zeolite containing an iron component by a hydrothermal synthesis method by a sol-gel method. The organic zeolite is a tertiary buthyl alcohol (TBA), an ammonia or an amine organic Synthetic materials used include trialkylamines containing tetra-propyl ammonium hydroxide (TPAOH), tetra-butyl ammonium hydroxide (TBAOH), tetra-ethyl ammonium hydroxide (TEAOH), tetra- trialkylamine, dialkylamine, or monoalkylamine may be used. In the present invention, the case of using TBA and TPAOH will be described.

First, when TBA is used, Al ₂ O ₃ and SiO ₂ , which are raw materials, are mixed at a predetermined blending ratio, and AIC, which is an iron raw material, and TBA, which is an organic support raw material, are mixed at a predetermined blending ratio to form a raw material mixture A mixed solution production step (S100) is carried out.

At this time, the range of the Al ₂ O ₃ in the raw material mixture based on 1 mol (mole) SiO ₂ 2 mol to 50 mol, TBA is 1.5 mol, and the molar ratio of the iron in accordance with the molar ratio of increase in the SiO ₂ is 0.1 mol To 1 mol, to prepare a raw material mixture.

To summarize, the molar ratio in the raw material mixture solution is Al ₂ O ₃ : SiO ₂ : Fe in the AIC: TBA = 1: 1 to 50: 0.1 to 1: 1.5 (where Fe in the AIC is defined as the molar ratio of Fe remaining in the AIC because the Fe concentration in AIC differs according to the solubility and other conditions) to be.

When the raw material mixture preparation step (S100) is completed, a mixed solution aging step (S200) is performed for aging the raw material mixture solution in a sol state into a gel mixture solution. The aging of the mixed solution is performed in a gel state by stirring the raw material mixture in a sol state at a temperature of 45 ° C to 55 ° C, preferably 50 ° C, for 20 hours to 30 hours, preferably aging for 24 hours.

The aged mixture is subjected to a hydrothermal synthesis step (S300) in an autoclave at about 100 ° C to 180 ° C for 40 to 50 hours, preferably 48 hours for hydrothermal synthesis.

The hydrothermally synthesized sample may be made into a final zeolite by a cleaning step (S400) in which the sample is washed and filtered and then dried at about 100 ° C.

If TPAOH is used as a substitute for TBA, the TPAOH may be replaced with an equimolar TPAOH. However, the TPAOH may be calcined at about 550 ° C to remove organic components in the TPAOH in the finishing step (S400).

As described above, the present invention relates to a zeolite synthesis method using a sol-gel method in which AIC, which is a chelate compound, is used as an iron component, and AIC and TPAOH or AIC and TBA are used to synthesize a porous zeolite containing an iron component do. However, it is much more economical to use TBA as an organic support because the TBA of the organic support is relatively lower than that of TPAOH.

Hereinafter, the experimental results of the method for producing the iron-containing porous zeolite according to the present invention will be described.

NaAl ₂ O ₃ was used as raw material for silica (SiO ₂ ) and Na ₂ SiO ₃ and aluminum (Al ₂ O ₃ ) as main raw materials for the production of aluminosilicate constituting the zeolite.

With a synthetic zeolite is Al ₂ O ₃ with a low molar ratio of SiO ₂ A type zeolite _{(Zeolite-A, Al 2 O} 3: SiO 2 = 1: 1) from Al ₂ O ₃ with a high molar ratio of SiO ₂ ZSM- 5 (Al ₂ O ₃ : SiO ₂ = 1: 50).

The iron components were compared with iron salts (FeCl ₃ ) and organic iron complexes (AIC: (NH ₄ ) ₅ Fe (C ₆ H ₄ O ₇ ) ₂ ). Materials for porosity were compared using tetra-propyl ammonium hydroxide (TPAOH) and tertiary butyl alcohol (TBA). Zeolite synthesis was carried out by hydrothermal synthesis by sol - gel method.

Zeolite 10 minutes after the reaction of ammonia-nitrogen (NH ₃ -N) Residual Concentration (mg / L) Zeolite-A 20 → 7.7 ^* AIC Zeolite-A
(Invention) Fe of AIC: 0.1 mole 20 → 7.5 Fe of AIC: 0.3 mole 20 → 6.3 Fe of AIC: 0.5 mole 20 → 6.0 ^** Fe Zeolite-A FeCl ₃ Fe: 0.1 mole 20 → 14.5 FeCl ₃ Fe: 0.3 mole 20 → 18.3 FeCl ₃ Fe: 0.5 mole 20 → 20

* AIC (ammonium iron citrate): (NH 4) 5 Fe (C 6 H 4 O 7) 2

** Fe: FeCl ₃

Table 1 compares the ion exchange and adsorption capacities of ammonia nitrogen with Zeolite-A containing no iron components, AIC Zeolite-A prepared with organic iron complexes, and Fe Zeolite-A prepared with iron salts. .

 In the case of Zeolite-A without iron component, the residual ammonia nitrogen concentration was about 8 mg / L. In the case of the organic iron complex AIC Zeolite-A of the present invention, the iron component was synthesized in the skeleton of the zeolite, Ion exchange capacity was similar. However, in the case of Fe Zeolite-A using iron salts, it was judged that the iron content was applied to the zeolite surface and the ion exchange capacity was lost as the iron salt concentration was increased.

Zeolite Specific surface area
(BET: m ² / g) pore volume
(cc / g) Iron content
(%) ZSM-5 400 0.13 - AIC ZSM-5
(Invention) 357 0.14 1.4 Fe ZSM-5 160 0.06 1.5

Table 2 compares the characteristics of the zeolites prepared by using iron salts and organic iron complexes to contain iron in the zeolite. In each case, the iron content was similar, but in the case of the iron salt, the reaction between the iron ion and the hydroxyl group The pore volume is reduced due to the formation of the iron oxide by the pore volume reduction and the pore volume is decreased.

On the other hand, when the organic iron chelate compound is used in the present invention, the specific surface area and the pore volume are maintained even if the iron content is high by reacting with the skeleton of the aluminosilicate without iron hydroxide formation.

1 shows an electron microscope (SEM) image and EDX mapping of the synthesized zeolite surface (A: zeolite in FIG. 1, B in FIG. 1: iron-containing zeolite prepared in AIC, (C) showed that the iron component was mainly distributed on the surface and distributed in a relatively large amount, whereas the organic iron complex compound (B) was relatively less distributed on the surface. This is because the organic iron complex is contained in the skeleton or channel rather than the zeolite surface.

2 shows the binding energy by photographing the synthesized zeolite surface using X-ray photoelectron spectroscopy (A: zeolite in FIG. 2, B in FIG. 2: iron-containing zeolite prepared by AIC, C in Fig. 2: iron-containing zeolite prepared from iron salts). In FIG. 2A, zeolite did not contain a bound iron component and did not show a peak. However, in the case of using iron salt in FIG. 2C, two peaks appeared, some of which reacted with the skeleton, . In the case of using AIC in FIG. 2B, it is shown that the peak is reacted with the whole skeleton.

FIG. 3 shows the results obtained by comparing TBA with zeolite prepared using TPAOH as an organic support in the present invention (A: porous zeolite prepared by TPAOH and B: porous zeolite prepared by TBA in FIG. 3) ). The results of this experiment show that TBA and TPAOH are similar to each other and can be replaced with TBA as a TPAOH substitute. TBA has a relatively low cost compared to TPAOH.

Organic support Specific surface area
(BET: m ² / g) pore volume
(cc / g) TPAOH 350 0.18 TBA (tertiary buthyl alcohol): The present invention 540 0.25

Table 3 compares the physical properties of the specific surface area and the pore volume with respect to TPAOH and TBA used as an organic support in the present invention. It can be seen that the use of TBA has a relatively high specific surface area.

On the other hand, FIGS. 4A to 4C show the removal efficiencies of BTEX (benzene, toluene, ethylbenzene, xylene) volatile materials for zeolite, iron salt, and zeolite using AIC as a ferrous material and TBA as a porous material, respectively Respectively.

4A shows that the removal efficiency of volatile materials is very low in the case of conventional zeolites and is slightly higher in the case of using iron salts according to FIG. 4B. According to FIG. 4C, the case of using AIC as the organic iron complex and TBA for the porous composition is It shows that the removal efficiency is higher than the case of using the iron salt. It is believed that this is due to the enhancement of adsorption capacity due to the formation of high porosity by TBA and the Fenton oxidation by AIC.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the present invention as defined by the following claims It can be understood that

Claims (12)

The ammonium iron citrate (C ₆ H ₈ O ₇ FeNH ₃ , hereinafter referred to as "AIC"), which is an organic iron complex, was used as a raw material for iron components by the hydrothermal synthesis method by the sol-gel method, (Tertiary buthyl alcohol) as an organic support for securing zeolite,
The raw material of the zeolite and the ammonia iron citrate (AIC) are mixed at a certain ratio so that the molar ratio in the raw material mixture is 1: 1 to 50: 0.1 to 1 in Al ₂ O ₃ : SiO ₂ : AIC (S100);
Aging a mixed solution for aging the raw material mixture with a mixed solution in a gel state (S200);
A hydrothermal synthesis step (S300) of hydrothermally synthesizing the aged mixed solution at a predetermined temperature in an autoclave; and
And a finishing step (S400) of drying the sample subjected to the hydrothermal synthesis by washing and filtering and drying at a predetermined temperature
A method for producing a porous zeolite containing an iron component.
delete delete delete delete The method according to claim 1,
In the mixed solution aging step (S200)
Agitating the raw material mixture solution for 20 hours to 30 hours while stirring at a temperature of 45 ° C to 55 ° C to form a gel state
A method for producing a porous zeolite containing an iron component.
The method according to claim 1,
The hydrothermal synthesis (S300)
The aged mixed solution is hydrothermally synthesized in an autoclave at 100 ° C to 180 ° C for 40 to 50 hours
A method for producing a porous zeolite containing an iron component.
The method according to claim 1,
The finishing step (S400)
Dried at a temperature of 100 ° C
A method for producing a porous zeolite containing an iron component. delete delete delete delete

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