KR20210144574A - Gas separation membrane containing heterogeneous zeolites and preparation method thereof - Google Patents

Abstract

The present invention relates to a gas separator in which heterogeneous zeolite epitaxially and alternately grows and a method for manufacturing the same, wherein MWW-based zeolite epitaxially grows to DDR-based zeolite or the DDR-based zeolite epitaxially grows to the MWW-based zeolite to form the gas separator, an MWW/DDR-based gas separator can be synthesized by using the structural continuity of the MWW-based zeolite and the DDR-based zeolite, and the gas separator manufactured thereby can have excellent separation efficiency.

Description

Gas separation membrane containing heterogeneous zeolites and preparation method thereof

The present invention relates to a gas separation membrane comprising MWW-based zeolite and DDR-based zeolite, and a method for manufacturing the same, and more particularly, to a gas separation membrane comprising DDR-based zeolite epitaxially grown on MWW-based zeolite.

Zeolite is a catalyst for the conversion of methanol to gasoline or denitrification of soot, and is a crystalline molecular sieve of alumina-silica having a regular three-dimensional framework structure by geometrically combining tetrahedra of _{SiO 4} and AlO ₄ ^-. They are connected by sharing oxygen, and the skeleton has a channel and a cavity connected to each other. Due to these characteristics, zeolite has excellent ion exchange properties and is therefore used in various applications such as catalysts, adsorbents, molecular sieves, ion exchangers, and separation membranes.

In the case of a conventional zeolite separator, the separation performance is greatly reduced due to defects larger than the inherent pore size of zeolite, which are inevitably generated when manufacturing the separator, and thus it is difficult to manufacture a high-performance separator.

Therefore, the development of a separation membrane with excellent separation performance by filling defects larger than the pore size of zeolite is required.

prior literature

Republic of Korea Patent Registration 10-0861012

An object of the present invention is to provide a gas separation membrane in which heterogeneous zeolites are epitaxially grown alternately with each other and a method for manufacturing the same. Specifically, the present invention provides a gas separation membrane in which DDR-based zeolite is epitaxially grown from MWW-based zeolite or MWW-based zeolite is epitaxially grown from DDR-based zeolite.

The present invention includes at least one MWW series zeolite and at least one DDR series zeolite, wherein the MWW series zeolite and the DDR series zeolite are provided alternately with each other, at least one of the MWW series zeolite and the DDR series zeolite is epi To provide a MWW/DDR-based gas separation membrane, which includes epitaxial growth.

In addition, the present invention provides a first zeolite for forming a first zeolite by providing a plurality of first zeolite particles prepared by a hydrothermal synthesis method on a support using a first zeolite precursor solution including a first structure directing agent and a first raw material formation step; and

A second zeolite forming step of growing a second zeolite on the first zeolite by hydrothermal synthesis using a second zeolite precursor solution containing a second structure directing agent and a second raw material;

The first or second raw material includes at least any one or more of Si and Al, respectively,

The first zeolite is provided in the form of a plurality of particles on the support, and the second zeolite is epitaxially grown on the first zeolite.

The gas separation membrane according to the present invention uses the structural continuity of the MWW-based zeolite and the DDR-based zeolite, and the gas separation membrane in which heterogeneous zeolites are epitaxially grown with each other can have excellent separation efficiency.

1 is a schematic diagram showing a cross-sectional view of a gas separation membrane according to an embodiment of the present invention.
2 is a flowchart illustrating a method for manufacturing a gas separation membrane according to an embodiment of the present invention.
3 is a schematic diagram showing a method for manufacturing a gas separation membrane according to an embodiment of the present invention.
4 is an image (ae) taken with a scanning electron microscope (SEM) and a graph (f) obtained by X-ray diffraction analysis of the gas separation membrane according to an embodiment of the present invention.
5 is an image showing a schematic structural model capable of epitaxial growth of DDR-based zeolite from MWW-based zeolite at the interface of the gas separation membrane according to an embodiment of the present invention.
6 is an image taken with a scanning electron microscope (SEM) of a gas separation membrane according to another embodiment of the present invention.
7 is a graph of X-ray diffraction analysis of a gas separation membrane according to another embodiment of the present invention.
8 is a graph of X-ray diffraction analysis of a gas separation membrane according to an embodiment of the present invention (a), a transmission electron microscope (TEM) image (b), a high-resolution transmission electron microscope (HR-TEM) image (c), and a high-speed An image of a Fourier transform (FFT) pattern (d).
9 is an image taken with a scanning electron microscope (SEM) of a gas separation membrane according to another embodiment of the present invention.
10 is a graph of X-ray diffraction analysis of a gas separation membrane according to another embodiment of the present invention.
11 is an image taken with a scanning electron microscope (SEM) of a gas separation membrane according to a comparative example of the present invention.
12 is a graph confirming the carbon dioxide separation capability of the gas separation membrane according to an embodiment of the present invention.
13 is a graph confirming the carbon dioxide separation capability of the gas separation membrane according to another embodiment of the present invention.
14 is a graph confirming the carbon dioxide separation capability of the gas separation membrane according to an embodiment of the present invention under dry and wet conditions.
15 is an image confirming the hydrophobicity of the gas separation membrane according to an embodiment of the present invention.
16 is a scanning electron microscope (SEM) and a fluorescence confocal optical microscope (FCOM) image of a gas separation membrane according to an embodiment of the present invention, (a) lines and (c) lines are cross-sectional images, (b) lines and (d) Lines are top-view images.
17 is an image of analyzing the characteristics of a fluorescence confocal optical microscope (FCOM) of a gas separation membrane according to an embodiment of the present invention.
18 is an image of analyzing the characteristics of a fluorescence confocal optical microscope (FCOM) of a gas separation membrane according to another embodiment of the present invention.
19 is an image schematically showing a defect structure of a gas separation membrane according to an embodiment of the present invention.
20 is an image obtained by analyzing fluorescence confocal optical microscopy (FCOM) characteristics of gas separation membranes according to other examples and comparative examples of the present invention.

Hereinafter, preferred embodiments according to the present invention will be described in more detail with reference to the accompanying drawings in order to describe the present invention in more detail. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms.

The zeolite separation membrane may function as a molecular sieve because the micropore size is constant. When the zeolite separation membrane is applied to the separation process, it is expected that the energy used in the existing separation process can be reduced. To date, 253 zeolite structures have been proposed. Nevertheless, a small number of zeolite structures (eg, MFI, FAU, CHA, DDR, MOR, LTA) have been synthesized as membranes.

When synthesizing a separation membrane, a method of synthesizing a separation membrane through secondary growth after forming a uniform seed layer is mainly used, and most of the seed layer and the separation membrane grown by secondary growth have the same structure.

DDR-based zeolite has a pore size of about 0.36 x 0.44 nm ² and _{can selectively separate CO 2} (0.33 nm) through a molecular sieve role. However, DDR-based zeolite is difficult to synthesize seed particles and has low reproducibility, making it difficult to form the seed layer of the separator.

In addition, MWW-based zeolites have been proposed as hydrogen-selective membranes because they have to pass vertically through 6-membered ring (MR) pores (0.28 nm) when oriented in the c-direction as plate-shaped particles. However, since it is difficult to form a separator oriented in the 6 MR pore direction, continuous separator formation and separation performance have not been reported.

The present invention comprises at least one MWW series zeolite and at least one DDR series zeolite,

The MWW series zeolite and the DDR series zeolite are alternately provided with each other, and at least one of the MWW series zeolite and the DDR series zeolite is epitaxially grown. to provide.

The MWW/DDR structure is a mutual growth of MWW series zeolite and DDR series zeolite, and one or more DDR series zeolites are epitaxially grown on one or more MWW series zeolites, but one or more MWW series zeolites are epitaxially grown on one or more DDR series zeolites. It means that you have grown up.

As an example, in the gas separation membrane of the present invention, the MWW-based zeolite and DDR-based zeolite independently form a layer, and may be alternately and repeatedly provided, and the thickness of the gas separation membrane is 0.1 to 50 μm, 0.1 to 30 μm, 0.5 to 10 μm, or 0.5 to 3 μm.

As an example, a DDR-based zeolite is epitaxially grown on the MWW-based zeolite by a hydrothermal synthesis method as a first condition, or an MWW-based zeolite is epitaxially grown on the DDR-based zeolite by a hydrothermal synthesis method as a second condition. It can be grown and equipped.

The first condition is a hydrothermal sequence for 0.5 days to 15 days, 1 day to 15 days, or 1 day to 10 days at a temperature of 100 °C to 200 °C, 100 °C to 180 °C, 120 °C to 160 °C or 130 °C to 160 °C. Including synthesizing, the second condition is 0.5 days to 15 days, 1 day to 15 days or 1 at a temperature of 100°C to 200°C, 100°C to 180°C, 120°C to 160°C or 130°C to 150°C It may include hydrothermal synthesis for 1 to 11 days.

The MWW series zeolite may have a Si:Al molar ratio of 100:0 to 10 or 100:1 to 10.

The DDR-based zeolite may have a Si:Al molar ratio of 100:0 to 10 or 100:0 to 1.

Since the gas separation membrane according to the present invention has a structure in which heterogeneous zeolites are alternately grown with each other as described above, and the heterogeneous zeolites are epitaxially grown with each other, carbon dioxide gas (CO ₂ ) is separated from the gas mixture. Gas separation efficiency can be further improved compared to the conventional separation membrane.

In addition, in the gas separation membrane of the present invention, when the DDR-based zeolite is provided on the MWW-based zeolite in the first direction (X) as shown in FIG. The MWW series zeolite particles have an average length (T1) parallel to each other in the first direction of 10 nm to 1 μm, 100 nm to 1 μm, 10 nm to 800 nm, 20 nm to 500 nm, 10 nm to 100 nm, or 50 nm to 100 nm .

In addition, when the MWW series zeolite is provided in the first direction (X) on the DDR series zeolite as shown in FIG. The DDR series zeolite particles have an average length (T2) parallel to the first direction of 0.1 μm to 10 μm, 0.1 μm to 5 μm, 0.5 μm to 5 μm, 1 μm to 5 μm, 0.5 μm to 3 μm or 0.1 μm to 1 μm.

In addition, as shown in FIG. 1(c), the plurality of MWW-based zeolite particles may be stacked in a multi-layer to form a first zeolite, and as shown in FIG. 1(d), the plurality of The DDR-based zeolite particles may be stacked in a multi-layer to form a first zeolite.

The MWW-based zeolite particles or the DDR-based zeolite particles may serve as a seed for forming the second zeolite as the first zeolite particles.

In addition, as shown in FIG. 2, the present invention provides a plurality of first zeolite particles prepared by hydrothermal synthesis using a first zeolite precursor solution including a first structure directing agent and a first raw material on a support to provide a first zeolite A first zeolite forming step to form a; and a second zeolite forming step of growing a second zeolite on the first zeolite by hydrothermal synthesis using a second zeolite precursor solution containing a second structure directing agent and a second raw material; 2 The raw materials each include at least one of Si and Al, the first zeolite is provided in the form of a plurality of particles on the support, and the second zeolite is epitaxially grown on the first zeolite. growth) provides a method for manufacturing a gas separation membrane comprising that.

Additionally, in the method for manufacturing a gas separation membrane according to the present invention, as shown in FIG. 3 , at least a portion of a plurality of first zeolite particles in the first zeolite forming step between the first zeolite forming step and the second zeolite forming step It may further include a buffer unit forming step of forming a buffer unit covering the.

In the buffer part forming step, a second zeolite may be grown on a plurality of particles of the first zeolite by hydrothermal synthesis using the first zeolite and the buffer part precursor solution.

The step of forming the buffer unit may be omitted. Structural stability can be further improved by making the interface between the first and second zeolites having different structures grow epitaxially by the buffer unit forming step.

The first or second raw material includes at least one of Si and Al, respectively.

The raw material containing Si may include _{any one or more of silica (SiO 2} ), monomeric silica, fumed silica, and colloidal silica.

The raw material containing Al may include an aluminum oxide salt, and specifically, the raw material containing Al may be _{NaAl 2} O _{3 .}

Specifically, when the first or second zeolite precursor solution is a solution for growing MWW-based zeolite, the first or second raw material includes Si and Al, and the molar concentration of the first or second zeolite precursor solution The ratio of Si: Al: structure directing agent: solvent = 100: 0 ~ 10: 10 ~ 500: 500 ~ 20000 or 100: 1 ~ 10: 10 ~ 500: 500 to 20000 may include.

In addition, when the first or second zeolite precursor solution is a solution for growing DDR-based zeolite, the first or second raw material contains Si, and the ratio of the molar concentration of the first or second zeolite precursor solution is Si:Al: structure directing agent: solvent = 100: 0 ~ 10:1 ~ 200: 500 ~ 20000 or 100: 0 ~ 1:1 ~ 200: 500 ~ 20000 may be.

The solvent may include distilled water, deionized water or ethanol.

The first and second structure-directing agents are independently hexamethyleneimine (Hexamethyleneimine, HMI), piperidine (Piperidine), adamantylamine (1-adamantylamine), ethylenediamine (ethylenediamine), methyltropinium salt, 1-TMAdaOH ( N,N,N-trimethyl-1-adamantylammonium hydroxide), TMAdaBr (N,N,N-trimethyl-1-adamantylammonium bromide), TMAdaF (N,N,N-trimethyl-1-adamantylammonium fluoride), TMAdaCl (N, N,N-trimethyl-1-adamantylammonium chloride), TMAdaI (N,N,N-trimethyl-1-adamantylammonium iodide), TEAOH (tetraethylammonium hydroxide), TEABr (tetraethylammonium bromide), TEAF (tetraethylammonium fluoride), TEACl (tetraethylammonium chloride) ), TEAI (tetraethylammonium iodide), dipropylamine (dipropylamine), and cyclohexylamine (cyclohexylamine), including any one or more.

The methyltropinium salt is methyltropinium iodide, methyltropinium fluoride, methyltropinium chloride, methyltropinium bromide, and methyltropinium hydroxide. (methyltropinium hydroxide) includes at least one selected from the group consisting of.

Specifically, among the first and second structure inducers, structure inducers for growing MWW-based zeolite include hexamethyleneimine (HMI), piperidine, TMAdaOH (N,N,N-trimethyl-1-adamantylammonium) hydroxide), TMAdaBr (N,N,N-trimethyl-1-adamantylammonium bromide), TMAdaF (N,N,N-trimethyl-1-adamantylammonium fluoride), TMAdaCl (N,N,N-trimethyl-1-adamantylammonium chloride) , and TMAdaI (N,N,N-trimethyl-1-adamantylammonium iodide) may be any one or more.

In addition, among the first and second structure inducers, the structure inducer for growing the DDR-based zeolite may be any one or more of methyltropinium salt, adamantylamine (1-adamantylamine), and ethylenediamine.

The support is α-alumina, γ-alumina, polypropylene, polyethylene, polytetrafluoroethylene, polysulfone, polyimide, silica, glass, mullite, zirconia, titania, yttria (yttria), ceria (ceria), vanadia (vanadia), silicon, stainless steel, carbon, includes any one or more of calcium oxide and phosphorus oxide.

In the first zeolite forming step, a plurality of first zeolite particles prepared by hydrothermal synthesis using a first zeolite precursor solution including a first structure directing agent and a first raw material are provided on the support to form a first zeolite is a step

The first zeolite forming step may consist of two steps as follows:

(1) a first zeolite particle forming step of forming a plurality of first zeolite particles by a hydrothermal synthesis method under a first condition or a second condition using the first zeolite precursor solution; and

(2) it may include a first zeolite forming step of depositing the first zeolite particles on a support using the suspension including the formed plurality of first zeolite particles.

When the first zeolite precursor solution is a solution for forming MWW-based zeolite particles, the first raw material includes Si and Al, and the molar concentration ratio of the first zeolite precursor solution is Si:Al: structure directing agent: solvent=100:0-10:10-500:500-20000 or 100:1-10:10-500:500-20000. Specifically, the first zeolite precursor solution for forming MWW-based zeolite particles is Si:Na:Al:Structure inducing agent:Solvent=100:10-100:0-10:10-500:500-20000 or 100:10- It may be a mixed solution in a ratio of 100:1 to 10:10 to 500:500 to 20000.

In addition, when the first zeolite precursor solution is a solution for forming DDR-based zeolite particles, the first raw material includes Si, and the molar concentration ratio of the first zeolite precursor solution is Si:Al: structure inducer: solvent=100:0-10:1-200:500-20000 or 100:0-1:1-200:500-20000. Specifically, the first zeolite precursor solution for forming DDR-based zeolite particles is SiO ₂ :Na:Al:Structure inducing agent:Solvent=100:10~100:0~10:1~200:500~20000 or 100:10 It may be included in a ratio of ~100:0~1:1~200:500~20,000.

The first condition is a condition for forming particles of DDR-based zeolite, at a temperature of 100°C to 200°C, 100°C to 180°C, 120°C to 160°C or 130°C to 160°C for 0.5 days to 15 days, 1 day It includes hydrothermal synthesis for 15 days or 1 day to 10 days, and the second condition is a condition for forming particles of MWW-based zeolite at 100° C. to 200° C., 100° C. to 180° C., 120° C. to 160° C. or It includes hydrothermal synthesis at a temperature of 130° C. to 150° C. for 0.5 days to 15 days, 1 day to 15 days, or 1 day to 11 days.

The first zeolite particle forming step may be further performed by heating and calcining at a temperature of 450 to 550° C. at a rising rate of 0.5 to 1.5° C./min for 12 to 40 hours after hydrothermal synthesis for 12 to 40 hours after hydrothermal synthesis. can

In addition, in the first zeolite forming step, the plurality of first zeolite particles prepared above and a plurality of first zeolite particles are formed on a support by using a suspension in which a solvent containing at least one of anhydrous toluene, ethanol, and distilled water is mixed. One or more layers may be deposited to form the first zeolite.

When forming the first zeolite under the conditions as described above, the average length T1 parallel to the first direction on the support (S) is 10 nm to 1 µm, 100 nm to 1 µm, 10 nm as shown in FIG. to 800 nm, 20 nm to 500 nm, 10 nm to 100 nm, or 50 nm to 100 nm may form a first zeolite by forming a plurality of first zeolite particles 100, wherein the first zeolite particles 100 are MWW-based zeolite particles can In addition, as shown in FIG. 1C , the plurality of first zeolite particles 100 may be stacked in a multi-layer on the support S to form a first zeolite.

Alternatively, as shown in (b) of FIG. 1 , the average length T2 parallel to the first direction (X) on the support S is 0.1 μm to 10 μm, 0.1 μm to 5 μm, 0.5 μm to 5 μm, 1 The first zeolite may be formed by forming the first zeolite particles 100 of μm to 5 μm, 0.5 μm to 3 μm, or 0.1 μm to 1 μm, and the first zeolite particles 100 are DDR-based zeolite particles. can In addition, as shown in FIG. 1D , the plurality of first zeolite particles 100 may be stacked in a multi-layer on the support S to form a first zeolite.

The first zeolite particles may serve as seeds for forming the second zeolite.

The thickness of the first zeolite may be 0.1 to 10 μm, 0.5 to 10 μm, 0.1 to 1 μm, or 1 to 10 μm, and when the first zeolite is a MWW series zeolite, the thickness of the first zeolite is 0.1 to 1 μm, and , When the first zeolite is a DDR-based zeolite, the thickness of the first zeolite may be 1 to 10 μm.

When the first zeolite is formed to have the same thickness as described above, the second zeolite may be grown to form a continuous crystal phase with the first zeolite particles.

The first zeolite forming step may further include heating and calcining at a temperature of 400 to 500° C. at a rising rate of 0.2 to 1.0° C./min for 12 to 40 hours after hydrothermal synthesis.

Through the calcination process as described above, the binding force of the first zeolite with the porous support layer may be increased, and a stable first zeolite may be formed.

In the buffer unit forming step, the second zeolite is epitaxially grown to form a continuous crystal phase with the plurality of first zeolite particles of the first zeolite, and serves as a precursor for three-dimensional growth of the second zeolite.

In the buffer unit forming step, the first and second zeolites may be formed of different types of zeolite, and the zeolite structure formed by the buffer unit precursor solution may be formed in the same manner as the second zeolite structure.

Specifically, the buffer part forming step is a buffer part precursor solution in which adamantylamine: ethyl rediamine: fumed silica: solvent is mixed at a molar concentration of 1-20:100-200:100:1000-20000. A buffer unit can be provided by hydrothermal synthesis using More specifically, using the buffer precursor solution on the first zeolite at a temperature of 100°C to 200°C, 100°C to 180°C, 120°C to 160°C, or 130°C to 160°C for 1 day to 5 days or 1 The buffer part may be formed on the first zeolite by hydrothermal synthesis for one to three days.

In the step of forming the buffer part, the second zeolite particles may be epitaxially formed from the first zeolite particles by forming the buffer part by the hydrothermal synthesis method under the conditions as described above.

The step of forming the buffer unit may further include heating and calcining at a temperature of 450 to 550° C. at a rate of 0.2 to 0.5° C./min for 12 to 40 hours after hydrothermal synthesis.

The second zeolite particles prepared through the calcination process as described above may be thermally activated, and the second zeolite particles may stably have a strong bonding force with the first zeolite.

The step of forming the second zeolite is a step of growing a second zeolite on the first zeolite by a hydrothermal synthesis method under a first condition or a second condition using a second zeolite precursor solution containing a second structure directing agent and a second raw material. am.

When the second zeolite precursor solution is a solution for forming a MWW-based zeolite, the second raw material includes Si and Al, and the molar concentration ratio of the second zeolite precursor solution is Si:Al:structure directing agent:solvent =100:0-10:10-500:500-20000 or 100:1-10:10-500:500-20000. Specifically, the second zeolite precursor solution for forming the MWW-based zeolite is Si:Na:Al:Structure inducing agent:Solvent=100:10-100:0-10:10-500:500-20000 or 100:10-100 It may be a mixed solution in a ratio of :1 to 10:10 to 500:500 to 20000.

In addition, when the second zeolite precursor solution is a solution for forming a DDR-based zeolite, the second raw material contains Si, and the molar concentration ratio of the second zeolite precursor solution is Si:Al: structure directing agent: solvent = 100:0 to 10:1 to 200:500 to 20000 or 100:0 to 1:1 to 200:500 to 20000. Specifically, the second zeolite precursor solution for forming the DDR-based zeolite is Si:Na:Al:Structure inducing agent:Solvent=100:10-100:0-10:1-200:500-20000 or 100:10-100 It can be included in a ratio of :0~1:1~200:500~20,000.

In the second zeolite precursor solution, the structure-inducing agent may be the methyltropinium salt, and as described above, the second zeolite is prepared by hydrothermal synthesis using the second zeolite precursor solution containing the methyltropinium salt to have the directionality of the continuous plane. can grow

Specifically, as the second zeolite grows from the plurality of first zeolite particles 100 formed on the support S as shown in FIG. 1 , one surface is formed to form the second zeolite layer 200 . 1 (a), when the plurality of first zeolite particles 100 are MWW-based zeolite particles, the second zeolite layer 200 may be formed of DDR-based zeolite, and in FIG. 1 (c) As described above, the second zeolite layer 200 may be formed on the first zeolite in which the plurality of first zeolite particles 100 are stacked in a multi-layered manner.

Alternatively, when the plurality of first zeolite particles 100 are DDR-based zeolite particles, as shown in (b) of FIG. 1, the second zeolite layer 200 may be formed of MWW-based zeolite. As described above, the second zeolite layer 200 may be formed on the first zeolite in which the plurality of first zeolite particles 100 are stacked in a multi-layered manner.

The first condition is a hydrothermal sequence for 0.5 days to 15 days, 1 day to 15 days, or 1 day to 10 days at a temperature of 100 °C to 200 °C, 100 °C to 180 °C, 120 °C to 160 °C or 130 °C to 160 °C. Including synthesizing, the second condition is 0.5 days to 15 days, 1 day to 15 days or 1 at a temperature of 100°C to 200°C, 100°C to 180°C, 120°C to 160°C or 130°C to 150°C Including hydrothermal synthesis for 1 to 11 days.

After the second zeolite forming step, the method may further include a rapid heat treatment at a temperature of 700 to 1200° C. for 10 seconds to 5 minutes.

Through the rapid heat treatment as described above, the width of cracks in the zeolite is reduced while the zeolite is reduced and the support is expanded, thereby improving gas permeation selectivity.

Examples of the present invention will be described below. However, the following examples are only preferred examples of the present invention, and the scope of the present invention is not limited by the following examples.

[Example]

The zeolites of Examples 1-2 and Comparative Examples 1-11 of the present invention were synthesized as follows, and the results are summarized in Table 1 below.

Synthesis of MWW series zeolite particles

First, NaOH (98% pellet, Sigma-Aldrich) and sodium aluminate (45 wt% Na ₂ O and 55 wt% Al ₂ O ₃ , Sigma-Aldrich) were added to deionized water (DI) in a plastic bottle. Then hexamethyleneimine (HMI, 97% Sigma-Aldrich) was added to the mixture. Fumed silica (CAB-O-SIL ^® M-5, Cabot Corporation) was slowly added to the solution with stirring. The final mass composition of the mixture is 1 SiO ₂ :0.1 NaOH : 0.03 NaAlO ₂ :0.8 HMI : 13.1 H ₂ O. The mixture was vigorously mixed overnight using a shaker, transferred to a Teflon liner, and the liner placed in a stainless-steel autoclave. The autoclave was transferred to an oven preheated to 135° C. and rotated at 40 rpm for 11 days. After 11 days, the autoclave was quenched by cooling with tap water. Then, the produced MCM-22(P) was recovered by repeating centrifugation and washing 5 times. MCM-22 particles were prepared by calcining the recovered particles in a furnace at 550° C. for 12 hours at a temperature increase rate of 1° C./min under an airflow of 200 mL/min.

MCM-22 Seed Layer Formation

A seed suspension was prepared by adding about 0.05 g of calcined MCM-22 particles to 40 mL of anhydrous toluene. _{α-Al 2} O ₃ disks sandwiched between cover glasses and placed vertically using a Teflon holder were sequentially placed in a dried glass reactor. After that, the glass reactor was sealed with parafilm and sonication (UC-10P, JEIO Tech, South Korea) was performed for about 20 minutes. After sonication was performed, the α-Al ₂ O ₃ disk was recovered and briefly washed with fresh toluene. The resulting MCM-22 seed layer was calcined at 450° C. for 12 hours at a temperature increase rate of 0.5° C./min under an air flow of 200 mL/min. At this time, the prepared MCM-22 seed layer is called Layer M (Comparative Example 1).

Heterogeneous film formation through secondary and tertiary growth

The MCM-22 seed layer was further exposed to secondary hydrothermal growth. First, the molar composition of the final sol is 1-adamantylamine (1-adamantylamine, 97%, Sigma-Aldrich):ethylenediamine (ethylenediamine, 99%, Sigma-Aldrich):fumed silica (CAB-O_Sil, M5):H ₂ A synthetic solution in which O is 9:150:100:4000 was prepared. Then, the side coated with the MCM-22 seed layer was placed on the Teflon liner with the help of a Teflon holder facing downward at an inclined angle. The synthesis solution was poured into a Teflon liner in a stainless-steel autoclave. The autoclave was transferred to an oven preheated to 160° C. and the reaction was carried out for 1 day, 2 days or 3 days, and then quenched by cooling with tap water. The recovered MCM-22 seed layer was extensively washed with deionized water and calcined at 550° C. for 12 hours at a heating rate of 0.5° C./min under an airflow of 200 mL/min in a furnace. At this time, the recovered α-Al ₂ O ₃ disk is represented by MD_xd (Comparative Example 2-4), where M is an MCM-22 seed layer, D is a DDR zeolite, and x is a hydrothermal reaction time (1 day, 2 days or 3 days) work) means

The calcined MD layer was intergrown using a synthetic precursor that allowed the synthesis of ZSM-58 (DDR-based zeolite). The calcined MD layer was placed in a synthetic precursor solution containing methyltropinium iodide (MTI) and hydrothermal synthesis was performed to grow a hydrophobic DDR zeolite separator with continuous out-of-plane orientation in three dimensions. Specifically, LUDOX HS-40 (40wt% suspension in H ₂ O, Sigma-Aldrich) serving as a silica source and methyltropinium iodide were added to deionized water together. The precursor solution thus prepared was mixed for about 1 hour using a stirrer. After additional NaOH was added, it was mixed well using a stirrer overnight. The molar composition of the synthetic precursor solution thus prepared is 100 SiO ₂ : 25 MTI: 30 NaOH: 4000 H ₂ O. After putting the alpha-alumina disk on which the calcined MD layer was formed into the precursor solution prepared in this way, hydrothermal synthesis was performed in an oven preheated to 130° C. at varying times (5 days or 10 days), and when the reaction was completed, it was quenched with tap water. The obtained separation membrane was immersed in deionized water and dried overnight in an oven at 100°C. The resulting product, the separation membrane, is expressed as MDZ_xd (Comparative Example 5-6), where M is MCM-22, D is DDR, Z: ZSM-58, and x is time hydrothermal synthesis reaction time for tertiary growth (day) is indicated.

In order to control the defect structure, the prepared separators (MDZ_5d, MDZ_10d) were treated using a rapid thermal processing (RTP) process as reported in the literature. Specifically, the prepared separator was placed in a quartz tube under an argon gas flow of 200 mL/min, and a preheated furnace (nominal, about 1000° C.) was quickly moved toward the separator. After 1 minute the furnace was moved away from the separator. Both the RTP-treated separation membrane and the non-RTP-treated separation membrane were further calcined at 550° C. for 12 hours at a temperature increase rate of 0.5° C./min under an airflow of 200 mL/min. The RTP-treated MDZ separator is denoted by MDZ_xd_RC (Example 1-2), where R in RC stands for rapid heat treatment and C stands for subsequent conventional calcination. Conversely, the separation membrane not subjected to RTP treatment is indicated as MDZ_xd_C (Comparative Examples 7-8).

In addition, to evaluate the structural compatibility of DDR/MWW for heteroepitaxial growth, the MCM-22 seed layer was exposed to secondary hydrothermal growth of MFI-based zeolite. The molar composition of the MFI zeolite synthesis sol is 40 SiO ₂ (tetraethylorthosilicate, TEOS, Sigma-Aldrich):9 tetrapropyl ammonium hydroxide (1.0M in H ₂ O, Sigma-Aldrich):9500 deionized water:160 ethanol am. The synthetic sol was poured into a Teflon lined autoclave in which the MCM-22 seed layer was placed as mentioned above. The autoclave was placed in a preheated oven at 175° C. and the reaction was performed for 1 day, 3 days and 5 days. The recovered MCM-22 seed layer was washed with deionized water, and further calcined at 550° C. for 12 hours at a temperature increase rate of 0.5° C./min under an airflow of 200 mL/min. For convenience, the obtained layer is denoted by MM_xd (Comparative Examples 9-11), where M and M denote MCM-22 and MFI zeolite, respectively, and x denotes a hydrothermal reaction time (1 day, 3 days or 5 days, respectively).

Category 1 seed layer formation secondary growth tertiary growth rapid heat treatment Comparative Example 1 Layer M O X X X Comparative Example 2 MD_1d O 1 day (DDR) X X Comparative Example 3 MD_2d O 2 days (DDR) X X Comparative Example 4 MD_3d O 3 days (DDR) X X Comparative Example 5 MDZ_5d O 3 days (DDR) 5 days X Comparative Example 6 MDZ_10d O 3 days (DDR) 10 days X Comparative Example 7 MDZ_5d_C O 3 days (DDR) 5 days basic calcination Comparative Example 8 MDZ_10d_C O 3 days (DDR) 10 days basic calcination Comparative Example 9 MM_1d O 1 day (MFI) X X Comparative Example 10 MM_2d O 2 days (MFI) X X Comparative Example 11 MM_3d O 3 days (MFI) X X Example 1 MDZ_5d_RC O 3 days (DDR) 5 days O Example 2 MDZ_10d_RC O 3 days (DDR) 10 days O

[Experimental example]

Membrane Characteristics

Fig. 4(a) shows that disk-shaped MCM-22 particles with a large ab-basal plane were uniformly deposited on a porous support using the ultrasonic treatment support method to form a continuous and dense seed layer. In particular, when the number of MCM-22 particles with an ab plane parallel to the surface of the support increased significantly, it was suggested that they were first synthesized in an out-of-plane direction (in this case, the c-axis is aligned in a direction perpendicular to the membrane surface). This c-out of plane was confirmed by the corresponding X-ray diffraction (XRD) measurement of FIG. 4(f). Looking at (b) of Figure 4, the DDR particles slightly grew due to the subsequent growth of the seed layer together with the precursor allowing the synthesis of DDR zeolite. Accordingly, the round shape of the MCM-22 particles was changed to a sharp shape with hexagonal edges, which means that heteroepitaxial growth was performed along the unit cells of the MWW-type zeolite.

Although MWW zeolite and DDR zeolite have different crystal structures, the heteroepitaxial growth of DDR zeolite in the ab plane of MWW zeolite appears to be formed along the c-axis. Referring to FIG. 5 , the structural compatibility between MWW and DDR series zeolites was formed along the c-axis, which seems to have resulted in heterogeneous epitaxial growth. Looking at FIG. 6, it can be seen that the heterogeneous epitaxial growth was difficult because the degree of secondary growth was not clear despite the plausible heterogeneous epitaxial growth, and as the secondary growth time increased from 1 day to 3 days, a sharp hexagonal shape It was confirmed that monotonously increased. However, due to the additional growth of plates grown vertically on the hexagonal plane of MD_xd with increased secondary growth time, MD_2d hydrothermally synthesized for 2 days was selected as the optimal time to form the MD layer. The reason is that it is intermediate between the formed MD_1d and MD_3d. In addition, looking at FIG. 7 , no distinct morphological change was observed in the MD_2d layer, but the extended growth resulted in undesired growth of new crystals. These new crystals are known to grow competitively with DDR family zeolites, so they are likely SGT type zeolites.

Referring to FIG. 8 , as a result of investigating the structural characteristics of the MD_2d layer, the Le Bail structural analysis method was used to match the XRD pattern of the MD_2d layer based on a combination of MWW and DDR series zeolites. Looking at the results, it was confirmed that the MD_2d layer was mainly composed of DDR series zeolite. However, Le Bail structural analysis could not account for the additional XRD peaks occurring on the aforementioned SGT zeolite. In addition, as a result of separating the particles from the MD_2d layer through ultrasonication and analyzing it through a transmission electron microscope (TEM), as shown in Fig. 8(b), particles with sharp edges were clearly identified, which was 22 It was confirmed that it grew from the deposit. Fig. 8(c) is a high-resolution transmission electron microscope (HR-TEM) image in the sharp edge region observed in Fig. 8(b), and the data was performed by fast Fourier transformation (FFT). The results are shown in Fig. 8(d). An additional pattern was observed, occurring in the [001] region axis of the MWW series zeolites along with the FFT pattern, likely belonging to the DDR series zeolites (white arrow). This was provided by simulated FFT patterns for the [001] domain axes of MWW and DRR zeolites, as in the image inserted in Fig. 8(d).

Although the hexagonal growth of the disk-like MCM-22 deposits in FIGS. 4(b) and 6 can be inferred from the scanning electron microscope (SEM) image of the MD_2d layer, the corresponding DDR zeolite growth is shown in FIG. 4(f) It was observed in the XRD pattern shown in Fig. 8(d), and the transmission electron microscope (TEM) analysis also shows the heterogeneous epitaxial growth (DDR/MWW) for the formation of the MD_2d layer. 4(c) and 9(ab), the subsequent hydrothermal growth of the MD_2d layer using a precursor that allows for the synthesis of ZSM-58 zeolite (DDR-based zeolite) clearly shows that MDZ_5d (Z is used for tertiary growth) (showing the ZSM-58 zeolite), which led to some intergrown layers, and further led to a continuous separator in MDZ_10d, as shown in FIGS. 4(de) and 9(cd). However, it is easy to find non-intergrowth parts in MDZ_5d as indicated by the white arrows. In addition, the proportion of ZSM-58 zeolite was supported by the increase of the XRD peak intensity as shown in Fig. 4(f) and Fig. 10 and increased as the growth period increased from 5 days to 10 days.

9 and 10 , the particles and crystalline phases of the high-speed thermal treatment process (RTP) rough separation membrane (MDZ_10d_RC) were indistinguishable from those of the comparative example (MDZ_10d_C), which was slowly calcined. Interestingly, the intensity of the XRD peak corresponding to the (003) plane of MDZ_10D was greatly increased, indicating that some c-out-of-plane orientation was formed. 4(f) and 7 clearly show that this c-out-of-plane direction was already present in the MD layer, and the amount steadily increased with increasing secondary growth time in the MCM-22 seed layer (layer_M). Referring to FIG. 5, it can be expected that this c-out-of-plane direction occurs from the disk-shaped MCM-22 particles constituting the MCM-22 seed layer and growth into hexagonal plates with sharp edges.

Figure 10 shows that the further hydrothermal growth from days 5 to 10 of the MD_2d layer favored the growth in the c-out-of-plane direction while maintaining the c-out-of-plane direction in MD_2d. This directional growth represents epitaxial growth from hexagonal plates in the presence of precursors that allow the synthesis of ZSM-58 zeolite. In particular, the crystallographic preferred orientation (CPO) index for MDZ_10d is estimated to be as high as 7.6±3.9, indicating a clear alignment of the c-axis in the out-of-plane direction.

To confirm the heterogeneous epitaxial growth, secondary growth was performed on the MCM-22 seed layer using a synthetic precursor that induces silicalite-1 (i.e., an MFI-type zeolite composed only of silica). Although it is known that MFI zeolite is easily formed in the presence of tetrapropyl ammonium (TPA) cations, it can be seen from Fig. 11 that the resulting layer is not continuous, making it difficult to close the gaps between the deposited MCM-22 particles. . Through this, it can be seen that structural similarity or compatibility between the two types of zeolites is required to form a heterogeneous epitaxial growth-based separator. Referring to FIG. 5, the hexagonal ring structure (6-MR) of the DDR series zeolite is located in a plane perpendicular to the c-axis in the heterogeneous separator of MDZ_10d. Therefore, preferentially, the c-out-of-plane oriented heterogeneous membrane (ie, MDZ_10d) had a significant number of 6-MR pore pores in the out-of-plane direction. In the separation membrane is a good platform for use in assessing the ability of the molecular sieve-6 MR hole to separate the H ₂ from the CO _2.

Separation performance of gas separation membrane

As expected from the discontinuity observed through scanning electron microscopy (SEM) shown in FIGS. 4(c) and 9(ab), looking at FIG. 12, neither MDZ_5d_C nor MDZ_5d_RC exhibited molecular sieve capability. Although the high-speed annealing process (RTP) helped, the degree of intergrowth of MDZ_5d, which achieved a slight increase in the separation performance, was not sufficient to secure the molecular sieve capability. 13 (a1-c1) shows that the previously calcined MDZ_10d_C showed _{poor separation performance for all three pairs of gases (H 2} /CO ₂ , CO ₂ /N ₂ , CO ₂ /CH ₄ ), which is a distinct defect. indicates that it exists. Despite the apparent film continuity in scanning electron microscopy (SEM) resolution in Fig. 9(d), MDZ_10d_C showed very poor permeation selection ability, indicating the importance of the method of calcination of the synthesized film or layer. In contrast, the membrane subjected to high-speed annealing process (RTP) (ie, MDZ_10d_RC) showed _{significantly improved permeation selectivity for CO 2} especially in all three cases, indicating that RTP contributed to the reduction of the degree of defects. In addition, although the 6-MR pore pores of MDZ_10d_RC are expected to contribute significantly to _{H 2 permeation, the corresponding H 2} /CO ₂ separation coefficient (SF) is about 0.37 (less than 1) at 30°C, and at 125°C. It was about 0.97. Also, the maximum H ₂ /CO ₂ SF was still very low at about 1.7 at 200°C. This means that the 6-MR pore aperture (maximum size 0.28 nm) was not suitable for _{maximal H 2} /CO _{2 - separation.} Because the structural properties of MDZ_10d_RC are similar to those of the homogeneous DDR separator, the H ₂ /CO ₂ , CO ₂ /N ₂ , CO ₂ /CH ₄ separation performance of MDZ_10d_RC was similar to that of the DDR separator, but much better throughout MDZ_10d_RC. It showed low CO ₂ permeability. For better comparison, looking at the middle and right columns of FIG. 13 , H ₂ /CO ₂ , CO ₂ /N ₂ , CO ₂ /CH ₄ separation performance of MDZ_10d_RC and the same kind of DDR separator is displayed together. Obviously, the CO ₂ transmittance of MDZ_10d_RC was reduced to a similar level when compared to the homogeneous DDR separator with more 8-MR channels in the direction perpendicular to the membrane surface. Thus 6-MR pore holes of the DDR zeolite is H ₂ / CO andago ₂ not suitable for the separation can be inferred, but the molecules of the H ₂ / CO ₂ separation using a 6-MR pores of different types of zeolite (no sodalite) You need to check your filtering capabilities. _{In particular, H 2} /CO ₂ separation under harsh conditions (high pressure and high temperature) is important for realizing a water-gas conversion membrane reactor, so it is essential to experiment with a zeolite membrane that can serve as a wall in the membrane reactor configuration. The above separation capability results can be seen to show that it is reasonable to achieve _{excellent H 2} /CO ₂ separation performance through post-treatment-based pore size reduction of zeolite having 8-MR or 10-MR. In actual literature, an MFI zeolite membrane with reduced pore size was used in the membrane reactor, and significant H ₂ recovery and CO ₂ conversion were obtained _{due to the high H 2} /CO _{2 separation coefficient through the membrane reactor.} In addition, referring to a1-a2 of FIG. 14 , when water vapor was added to the feed of the two-component mixture, _{the permeability of H 2} and CO ₂ was reduced at a temperature below 100° C., which is a temperature at which the degree of water adsorption of DDR zeolite is evident. In contrast, _{the permeability of H 2} and CO ₂ did not change due to the presence of water vapor at temperatures above 100° C. Interestingly, the degree of transmittance reduction was similar up to 200° C. for both _{H 2} and CO _{2 . Therefore, the corresponding H 2} /CO ₂ separation coefficient in the wet condition of a2 of FIG. 14 was similar to _{the H 2} /CO ₂ separation coefficient under the dry condition of a1 of FIG. 14 . In addition, reducing the CO ₂ permeability from less than b1-b2 When the water vapor feed is in particular 100 ℃ of 14 increased the CO ₂ / N ₂ separation factor (SF). In contrast to FIG. C1-c2 to look at a reduced transmittance of 14 CO ₂ / CH was ₄ release was higher for CO ₂ than CH ₄ in the equivalent CO ₂ / CH ₄ separation factor (SF) to about 50 in a wet condition in accordance with decreased to °C. In particular, the water vapor-induced CO ₂ /N ₂ and CO ₂ /CH ₄ separation trends were very similar to those of the reported homogeneous DDR membranes. The main difference is that the CO ₂ transmittance is lowered in the aforementioned MDZ_10d_RC, which occurs in a significant proportion of DDR zeolites with clearly c-out-of-plane orientation. Referring to FIG. 15 , the higher CO ₂ /N ₂ separation factor (SF) in wet conditions may be due to the hydrophobicity of the siliceous DDR zeolite in MDZ_10d_RC (see the inset image of FIG. 4 (e)). In contrast, in the measurement of the contact angle of MDZ_10d_C, the water droplets disappeared quickly, confirming that MDZ_10d_C had many defects.

16 is a fluorescence confocal optical microscopy (FCOM) image of MDZ_10d_C and MDZ_10d_RC. Referring to FIG. 13, respectively, it can be seen that MDZ_10d_C is low and MDZ_10d_RC is good in _{CO 2 transmission selectivity.} Accordingly, it can be seen that the corresponding defect degree is high in MDZ_10d_C and low in MDZ_10d_RC. The contribution of defects, particularly cracks, to the actual measured transmittance is a combined function of the size (width) and number (density) of the defects, so these factors must be considered together to understand the final apparent performance. In addition, staining the separator for various periods of time provides additional information about the defect structure. Defects (mainly cracks) in MDZ_10d_C were more and more progressively penetrated by dye molecules with increasing staining time. In particular, some cracks reaching the interface between the zeolite membrane and the porous support were only visualized after 12 h of dye contact (indicated by yellow arrows in Fig. 16 a2). Conversely, looking at c2-d2 of FIG. 16 , as indicated by a yellow dotted line in c2 of FIG. 16 , MDZ_10d_RC had a high density or a large number of cracks, but did not completely propagate to the interface. Referring to a3-b3 of FIG. 16, more cracks propagating to the interface were visualized through long-term staining of MDZ_10d_C (24 h). In contrast, the number of cracks in MDZ_10d_RC detected after 12 h staining remained the same, but more dye molecules could access the region closer to the interface, but only existed in the middle of the separator (indicated by the yellow dotted line in Fig. 16 c3). Finally, additional cracks in MDZ_10d_C propagated to the interface were observed after 60 h of staining, and the higher number or density of cracks present in MDZ_10d_RC were completely approached by dye molecules.

Referring to FIGS. 17 and 18 , it was confirmed that the number and size of cracks present in MDZ_10d_C were smaller and larger than the number and size of cracks present in MDZ_10d_RC through the dyeing process at different times. Image processing of fluorescence confocal optical microscopy images provided further confirmation of the number of defects. Referring to Table 2, the pixel-based area fraction was 0.020 for MDZ_10d_C and 0.035 for MDZ_10d_RC. After the image processing was completed, the crack characteristics were well reconstructed as shown in FIG. 19 . Despite the difference in crack density, the torsion of cracks according to the thickness of the separator was about 1.6 for both MDZ_10d_C and MDZ_10d_RC, as shown in Table 2, which means that molecules penetrating the separator should follow a similarly slightly inclined path. Referring to FIG. 20 , the cracking characteristics of MDZ_10d_C were similar to those of the same type of DDR separator, but the number of cracks in MDZ_10d_RC was higher. Considering that the homogeneous DDR separator showed high CO ₂ permeation selectivity, the crack size of MDZ_10d_C was clearly too large to obtain molecular sieve capability. Currently, the rapid annealing process (RTP) is known to effectively reduce the defect size by condensing particles in the polycrystalline zeolite separator, but FIG. 16 shows a larger number of small cracks when the rapid annealing process (RTP) is performed before the conventional slow calcination It shows that it is possible to reduce the stress generated during the removal of the structural directing agent (SDA). In summary, MDZ_10d_RC, which had a higher number of defects but showed better isolation performance than MDZ_10d_C, shows that reducing the size of defects is a more important factor to ensure good isolation performance.

Membrane sample Tortuosity in the z-direction;
along the membrane thickness Defect area fraction MDZ_10d_C 1.57 0.020 MDZ_10d_RC 1.59 0.035

Claims (17)

at least one MWW series zeolite and at least one DDR series zeolite;
The MWW-based zeolite and the DDR-based zeolite are alternately provided with each other, and at least one of the MWW-based zeolite and the DDR-based zeolite is epitaxially grown. According to claim 1,
The MWW-based zeolite and the DDR-based zeolite independently form a layer, but alternately and repeatedly provided with a gas separation membrane. According to claim 1,
The MWW series zeolite is a gas separation membrane having a Si:Al molar ratio of 100:0 to 10. According to claim 1,
The DDR series zeolite is a gas separation membrane having a Si:Al molar ratio of 100:0 to 10. According to claim 1,
DDR-based zeolite is epitaxially grown by hydrothermal synthesis under the first condition on the MWW-based zeolite, or
A gas separation membrane provided by epitaxially growing MWW-based zeolite on the DDR-based zeolite by hydrothermal synthesis under the second condition. 6. The method of claim 5,
When the DDR series zeolite is provided on the MWW series zeolite in the first direction, the MWW series zeolite consists of a group of a plurality of MWW series zeolite particles, and the MWW series zeolite particles have an average length parallel to the MWW series direction. 10 nm to 1 μm,
When the MWW series zeolite is provided on the DDR series zeolite in the first direction, the DDR series zeolite is composed of a plurality of DDR series zeolite particles, and the DDR series zeolite particles have an average length side by side in the first direction Gas separation membrane comprising a 0.1㎛ to 10㎛. 7. The method of claim 6,
The first and second conditions are independently hydrothermal synthesis at a temperature of 100°C to 200°C for 0.5 to 15 days. According to claim 1,
The gas separation membrane is a gas separation membrane that separates _{carbon dioxide gas (CO 2 ) from the gas mixture.} A first zeolite forming step of forming a first zeolite by providing a plurality of first zeolite particles prepared by a hydrothermal synthesis method on a support using a first zeolite precursor solution including a first structure directing agent and a first raw material; and
A second zeolite forming step of growing a second zeolite on the first zeolite by hydrothermal synthesis using a second zeolite precursor solution containing a second structure directing agent and a second raw material;
The first or second raw material includes at least any one or more of Si and Al, respectively,
wherein the first zeolite is provided in the form of a plurality of particles on the support, and the second zeolite is epitaxially grown on the first zeolite. 10. The method of claim 9,
The first zeolite has an average length of particles of 10 nm to 1 μm,
The ratio of the molar concentration of the first zeolite precursor solution is Si: Al: structure directing agent: solvent = 100: 0 ~ 10: 10 ~ 500: 500 ~ 20000,
The ratio of the molar concentration of the second zeolite precursor solution is Si: Al: structure directing agent: solvent = 100: 0 ~ 10:1 ~ 200: 500 ~ 20000 method of manufacturing a gas separation membrane. 10. The method of claim 9,
The first zeolite has an average length of particles of 0.1 μm to 10 μm,
The ratio of the molar concentration of the first zeolite precursor solution is Si: Al: structure directing agent: solvent = 100: 0 ~ 10:1 ~ 200: 500 ~ 20000,
The ratio of the molar concentration of the second zeolite precursor solution is Si: Al: structure directing agent: solvent = 100: 0 ~ 10: 10 ~ 500: 500 ~ 20000 method of manufacturing a gas separation membrane. 10. The method of claim 9,
The first and second structure-directing agents are independently hexamethyleneimine (Hexamethyleneimine, HMI), piperidine (Piperidine), adamantylamine (1-adamantylamine), ethylenediamine (ethylenediamine), methyltropinium salt, 1-TMAdaOH ( N,N,N-trimethyl-1-adamantylammonium hydroxide), TMAdaBr (N,N,N-trimethyl-1-adamantylammonium bromide), TMAdaF (N,N,N-trimethyl-1-adamantylammonium fluoride), TMAdaCl (N, N,N-trimethyl-1-adamantylammonium chloride), TMAdaI (N,N,N-trimethyl-1-adamantylammonium iodide), TEAOH (tetraethylammonium hydroxide), TEABr (tetraethylammonium bromide), TEAF (tetraethylammonium fluoride), TEACl (tetraethylammonium chloride) ), TEAI (tetraethylammonium iodide), dipropylamine (dipropylamine), and cyclohexylamine (cyclohexylamine) manufacturing method of a gas separation membrane comprising any one or more. 10. The method of claim 9,
The support is α-alumina, γ-alumina, polypropylene, polyethylene, polytetrafluoroethylene, polysulfone, polyimide, silica, glass, mullite, zirconia, titania, yttria (yttria), ceria (ceria), vanadia (vanadia), silicon, stainless steel, carbon, a method of manufacturing a gas separation membrane comprising any one or more of calcium oxide and phosphorus oxide. 10. The method of claim 9,
Between the first zeolite forming step and the second zeolite forming step,
Further comprising a buffer portion forming step of forming a buffer portion covering at least a portion of the plurality of first zeolite particles in the first zeolite forming step,
The buffer part forming step is performed using a buffer part precursor solution in which adamantylamine: ethyl rediamine: fumed silica: solvent is mixed at a molar concentration of 1-20:100-200:100:1000-20000. A method for producing a gas separation membrane by providing a buffer portion on the first zeolite by hydrothermal synthesis. 15. The method of claim 14,
In the buffer unit forming step,
The first and second zeolites are made of different types of zeolite, and the zeolite structure formed by the buffer part precursor solution is the same as the second zeolite structure. 10. The method of claim 9,
The first zeolite forming step and the second zeolite forming step are independently heated and calcined at a temperature of 450 to 550° C. at a rising rate of 0.2 to 0.5° C./min for 12 to 40 hours after hydrothermal synthesis. Gas A method for manufacturing a separation membrane. 10. The method of claim 9,
The method of manufacturing a gas separation membrane further comprising the step of rapid heat treatment for 10 seconds to 5 minutes at a temperature of 700 ~ 1200 ℃ after the second zeolite forming step.

Images