KR20050029362A - Mesoporous ceramic structure, and preparation method for the same - Google Patents

Abstract

Provided is a method for preparing mesoporous ceramic structures having a new crystal structure different from the crystal structure of silica template by using mesoporous silica as a template. A cubic mesoporous ceramic structure having a new crystal structure is prepared by using mesoporous silica as a template. The silica template has 2-3mm of diameter, a pair of mesopore channel(not interconnected) in a mirror-image relation and strong XRD peak at 2theta=2.35deg, and a new structured mesoporous ceramic structure has 4-4.5mm of diameter, homogeneous mesopore channel(interconnected), and strong XRD peak at 2theta=1.64deg and weak XRD peak at 2theta=2.74deg corresponding to the peak of the silica template. The mesoporous ceramic structure is prepared by the following steps of: (i) preparing a mesoporous silica template(M48T) from organic surfactant and silica-source; (ii) preparing a silica-carbon template composite(M48T-carbon composite) by pouring a carbon precursor into mesopore of the silica template(M48T) and carbonizing, wherein the carbon precursor is an addition polymer obtained by polymerizing divinyl benzene with azobisisobutyro nitrile(AIBN) or a condensation polymer obtained by polymerizing phenol and formaldehyde under AlCl3 catalyst; (iii) preparing a mesoporous carbon structure(M48T-C) by etching the silica-carbon template composite with HF or NaOH to remove silica used as a template; (iv) preparing a mesoporous carbon structure(HUM-1) by pouring ceramic precursor, such as silica precursor(tetraethoxy silane(TEOS)), into the mesopore of mesoporous carbon structure and sintering.

Description

Mesoporous ceramic structure, and preparation method for the same

The present invention relates to a mesoporous ceramic structure, a mesoporous carbon structure that can be used as a template for the production of the mesoporous ceramic structure, and a method of manufacturing the same.

Conventional mesoporous silica materials, such as M41S or SBA-1, can be prepared using basic template solutions such as cetyltrimethylammonium bromide (CTMABr), cetyltrimethylammonium chloride (CTMACl), or basic aqueous solution conditions. It is reported to be prepared under acidic aqueous solution conditions [CT Kresge, ME Leonowicz, WJ Roth, JC Vartuli and JS Beck, Nature , 1992 , 359 , 710; JS Beck, JC Vartuli, WJ Roth, ME Leonowicz, CT Kresge, KD Schmitt, CT-W. Chu, DH Olson, EW Sheppard, SB McCullen, JB Higgns and JL Schlenker, J. Am. Chem. Soc ., 1992 , 114 , 10834; Q. Huo, DI Margolese, U. Ciesla, DG Demuth, P. Feng, TE Gier, P. Sieger, A. Firouzi, BF Chmelka, F. Schuth and GD Stucky, Chem. Mater ., 1994 , 6 , 1176; Q. Huo, R. Leon, PM Petroff and GD Stucky, Science , 1995 , 268 , 1324.]. Although many studies have been conducted after the method of preparing mesoporous materials using organic template, research on the preparation of mesoporous materials having a new structure in addition to the initially reported crystal structure is weak. Recently, a new mesoporous silica structure, a structure similar to the hexagonal MCM-41 structure with honeycomb pores, one of the M41S structures, is a P123 (EO ₂₀ PO ₇₀ EO ₂₀ , M _av = 5800) using a polymer template [D. Zhao, J. Feng, Q. Huo, N. Melosh, GH Fredrickson, BF Chmelka and GD Stucky, Science , 1998 , 279 , 548.].

Recently, a technique for synthesizing mesoporous silica materials using a new template has been reported as in the present invention. After carbohydrate is injected into mesoporous SBA-15 silica mold and carbonized, the mold is removed to prepare CMK-3, a new macroporous carbon material having a regular and constant size, and the prepared CMK-3 carbon mold. After preparing a tetraethylorthosilicate (TEOS, 98%) or sodium metasilicate (Na ₂ SiO ₃ ) aqueous solution of silica precursor, the silica precursor was sintered and the carbon template was removed to prepare mesoporous silica material. An-Hui Lu, Wolfgang Schmidt, Akira Taguchi, Bernd Spliethoff, Bernd Tesche and Ferdi Schueth, Angew. Chem. Int. Ed., 2002 , 41 (18) , 3489; Min Kang, Seung Hwan Yi, Hyung Ik Lee, Jae Eui Yie and Ji Man Kim, Chem. Commun., 2002 , 1944.]. The silica precursor TEOS (98%) was injected into a hollow, double-porous nanocapsule carbon structure mold having a uniform sized mesoporous shell and containing metal nanoparticles with specific activities and functions. After the precursor is treated, the carbon used as a template is removed to have a mesoporous shell, and a hollow biporous nanocapsule silica structure manufacturing method containing metal nanoparticles therein has been reported by the inventors [Jeong Yeon Kim, Suk Bon Yoon, and Jong-Sung Yu, Chem. Commun ., 2003 , 790; See Korean Patent Application No. 10-2003-0056377].

However, in the above-described conventional technique, the mesoporous silica using the CMK-3 template has the SBA-15 structure, which is the initial template used for the preparation of the CMK-3, and thus it is impossible to produce the mesoporous silica material and the ceramic material of the new structure. Do.

It is a first object of the present invention to provide a mesoporous ceramic structure having a new crystal structure.

A second object of the present invention is to provide a method for producing a mesoporous ceramic structure having the new crystal structure.

The mesoporous ceramic structure having a novel crystal structure according to the first object of the present invention is a cubic mesoporous structure, having uniform mesoporous channels interconnected three-dimensionally in part of periodically aligned nanostructures, and interconnected. It is made from a mesoporous silica mold having a pair of mesoporous channels of non-mirror relationship, and has a crystal structure different from that of the silica template. For example, using a silica mold having a diameter of about 2-3 nm and having a pair of mesoporous channels of non-interconnected mirror image and exhibiting a strong XRD peak at 2θ = 2.35 °, The mesoporous ceramic structure having a new crystal structure according to the first object of the present invention, which is manufactured through the present invention, has a diameter of about 4-4.5 nm and is three-dimensionally partially interconnected uniformly mesoporous of highly periodically aligned nanostructures. Weak at one position that did not exist in the channel and in the original silica template, for example one strong XRD peak at 2θ = 1.64 ° and a peak present in the original silica template, for example 2θ = 2.74 ° It has a new crystal structure and particle structure showing XRD peaks.

The method for producing the mesoporous ceramic structure of the new crystal structure according to the second object of the present invention includes the following steps, as shown in FIG.

a) preparing a mesoporous silica template (M48T);

b) preparing a silica-carbon template composite (M48T-carbon composite);

c) preparing a mesoporous carbon structure (M48T-C); And

d) preparing a mesoporous ceramic structure (HUM-1).

The method of manufacturing a mesoporous ceramic structure of the new crystal structure may further include e) repeating the steps b) to d) using the mesoporous ceramic structure (HUM-1) as a template to form a mesoporous ceramic structure of a new material. It may comprise the step of manufacturing.

Hereinafter, the present invention will be described in more detail.

The mesoporous silica template synthesized in the first step in the two manufacturing methods of the present invention, prepared by the molecular size of the surfactant used as the organic template and various synthetic conditions, the pore size is adjustable in the range of 1.5 to 30 nm Because of the large surface area, there are various applications. In addition, by adding metal ions such as aluminum (Al) and titanium (Ti) to the silica manufacturing process having mesopores, it is possible to produce mesoporous metal silica in which a metal other than silicon (Si) is supported in the silica structure. Catalysis by metals and ion exchange of transition metals have the potential for application as various catalysts. In addition, when the mesoporous silica structure is used as a mold, there is an advantage in that a new mesoporous carbon having a controlled pore size and a wall thickness can be easily manufactured, and the manufactured carbon material also has a wide surface area with various sizes of mesoporous. do. Although a mesoporous silica material having various crystal structures can be synthesized using a surfactant as a template, it is difficult to prepare various mesoporous metal oxide structures. In addition, when preparing a metal oxide with a mesoporous silica, it is difficult to remove only silica. In order to overcome this problem, a study has been reported to use a mesoporous carbon structure prepared through a mesoporous silica mold as a template. In particular, a carbon structure prepared by using mesoporous MCM-48 silica having a cubic crystal structure has a phase change in the process of removing the silica template, thereby producing a carbon structure having a new crystal structure.

According to the present invention, a mesoporous MCM-48 silica structure is prepared using a surfactant, the prepared MCM-48 silica is calcined to remove a surfactant, and various polymer precursors are injected into empty mesopores, followed by a polymer precursor. When the polymer is molded through a polymerization reaction of the polymer precursor, the polymer is polymerized to obtain a polymer-silica template composite, and the formed polymer-silica composite is obtained by carbonizing the carbon-silica composite at a temperature of 900 ° C. to 1000 ° C. under an inert gas. . The carbon-silica complex is treated with hydrofluoric acid (HF) solution, sodium hydroxide (NaOH) or potassium hydroxide (KOH) solution to remove the silica used as the template, and the mesoporous MCM-48 silica structure used as the template and other mesoporous carbon The structure can be manufactured. The mesopore of the prepared mesoporous carbon structure is larger than the pore wall thickness of the mesoporous MCM-48 silica used as a template, and the carbon wall thickness is smaller than the size of the silica mesoporous used as the template. In the process, the crystal of the silica template shrinks and the process of removing the silica template is caused by the phase change of the mesoporous carbon wall. The mesoporous carbon materials produced also have a large surface area and uniform sized mesopores. The PXRD (powder X-ray diffraction) pattern of FIG. 2, the transmission electron microscope (TEM) photograph of FIG. 3, and the BET surface area results by the nitrogen (N ₂ ) adsorption-desorption analysis of FIG. 4 can be confirmed. .

The present invention provides a method for producing a mesoporous carbon structure prepared using a calcined mesoporous MCM-48 silica template, and a mesoporous ceramic structure having a new crystal structure using the prepared carbon structure as a template. The mesoporous ceramic structure thus prepared may be applied as a catalyst, an adsorbent, a separation and purification process, a catalyst support, a template.

Hereinafter, the steps included in the method of manufacturing the mesoporous ceramic structure of the new crystal structure and the mesoporous carbon structure of the new crystal structure according to the present invention will be described in detail.

First step: preparation of mesoporous silica template (M48T)

The mesoporous silica structure to be used as a template in the present invention is prepared based on the method described in the known art. For example, Ryoo, R., Joo. SH, Kim, JH J. Phys. Chem. Although the mesoporous silica structure can be prepared according to the method disclosed in B 1999, 103, 7435, in one preferred embodiment of the present invention, the mesoporous silica structure is prepared to use the mesoporous silica structure prepared as a template. Each can be handled differently. Namely, AM48T, which contains only a surfactant, is dried at 100 ° C .; A portion of the surfactant was washed, filtered and washed with 0.1M HCl / EtOH solution and WM48T dried at 100 ° C .; Then, three molds of CM48T calcined at 540 ° C. are prepared (hereinafter, three are collectively referred to as M48T).

The unit structure of the M48T mesoporous silica template prepared above is shown schematically in FIG. 6. Referring to FIG. 6, in the M48T template, mesopores A and B which are not interconnected like two mirror images having a constant diameter of about 3 nm are distributed in the silica structure in three dimensions. And these two mesopores are blocked by the silica wall C. The mesopores of such a complicated structure are represented by a straight line in FIG. In the next step below, a carbon precursor such as a polymer monomer and polymerization initiator mixture is introduced into mesopores A and B. In the process of chemically etching and removing the silica wall, two mesopores are partially bonded to each other.

Second Step: Preparation of Silica-Carbon Template Composite (M48T-Carbon Composite)

After injecting a polymer precursor into the mesopores of the three templates prepared in the first step, the mesoporous silica structures (AM48T, WM48T and CM48T), the polymer precursor is polymerized to prepare a polymer-silica mold composite, and the prepared composite is Carbon-silica template composites are prepared via carbonization under inert gas. According to the three templates presented above, three carbon-silica template composites are obtained.

The carbon precursor is divinylbenzene, acrylonitrile, vinyl chloride, vinyl acetate, styrene, methacrylate, methyl methacrylate, ethylene glycol dimethacrylate, urea, melamine or CH ₂ = CRR ' Monomers such as azobisisobutyronitrile (AIBN), t-butyl peracetate, benzoyl peroxide (BPO), and acetyl peroxide (acetyl peroxide) or polymers prepared by addition polymerization using a lauryl peroxide initiator, phenol-formaldehyde, phenol, furfuryl alcohol, resorcinol-formaldehyde (RF) Selected from polymers or mesophase pitches prepared by condensation polymerization of monomers such as aldehydes, sucrose, glucose or xylose using an acid catalyst such as sulfuric acid or hydrochloric acid Or by the carbonization reaction it includes other carbon precursor to form a non-graphitizing carbon (graphitic carbon). The addition polymerizable monomers may be used alone or in a mixture of two or more monomers. At this time, the molar ratio of the monomer and the initiator is 15: 1 to 35: 1. The condensation polymerizable monomer may also be used alone or as a mixture of two or more monomers, wherein the molar ratio of the monomer and acid catalyst is about 5: 1 to 15: 1.

The monomer and the initiator or monomer and acid catalyst mixture is injected in an amount of 20 to 30% by volume based on the prepared mesoporous silica template, and the injection of the mixture may be in a liquid phase or a gaseous phase. More specifically, the mixture may be added to the silica mold in the liquid phase, or the solid material in vacuo may be heated and injected into the mesopores of the mold in the gas phase.

The mesoporous silica template infused with a mixture of the addition-polymerizable monomer and the required initiator is polymerized under different known optimum conditions depending on the polymerizable compound used, but preferably for 3 to 30 hours at a temperature of 60 to 90 ° C. Polymerize. In the case of the condensation polymerizable monomer and the acid catalyst mixture, the polymerization may be carried out under other known optimum conditions depending on the condensation polymerizable compound used. In both cases, upon completion of the polymerization, a polymer-silica template complex is obtained. The acid, which is a catalyst during the condensation polymerization, may form an acid site on the surface of silica so that the mold exhibits its own acid catalyst characteristics, or an acid catalyst (hydrochloric acid, sulfuric acid, etc.) may be added from the outside to act as a catalyst during the condensation reaction of the polymer monomer. .

The polymer-silica composite is subjected to high temperature heat treatment at a temperature of 800 to 1500 ° C. under an inert gas for 5 to 15 hours to carbonize the polymer to obtain a silica-carbon composite (M48T-carbon composite). At this time, the temperature increase rate is in the range of 1 ° C / min to 100 ° C / min.

This step is described in detail in Korean Patent Application No. 10-2002-0008376 to which the inventor has applied for a patent, the contents of which are incorporated by reference in the present specification as a whole.

Third Step: Fabrication of Mesoporous Carbon Structure (M48T-C Structure)

The three carbon-silica template complexes prepared in the second step were treated with hydrofluoric acid (HF) solution, sodium hydroxide (NaOH) or potassium hydroxide (KOH) solution to remove silica used as a template, filtered and washed. After drying in a drying oven (70 ~ 100 ℃). This step is described in detail in Korean Patent Application No. 10-2002-0008376 to which the inventor has applied for a patent, the contents of which are incorporated by reference in the present specification as a whole.

The mesoporous carbon structure thus prepared is a new cubic phase structure different from the mold (AM48T, WM48T, CM48T) structure used as a template, which is an inverse replica of AM48T-C and WM48T-C. And CM48T-C. The three carbon replicas thus obtained show the same structure irrespective of the silica template and are thus designated CM48T-C without particular distinction.

Fourth Step: Fabrication of Mesoporous Ceramic Structure (HUM-1)

Ceramic-M @ carbon composites are synthesized by injecting a ceramic precursor into the mesopores of the mold using each of the three mesoporous carbon structures prepared in the third step, and converting the ceramic precursor into a ceramic. Types of ceramics that can be manufactured may include TiO ₂ , SnO ₂ , ZnO ₂ , ZrO _2, and Al ₂ O ₃ , but are not limited thereto.

A ceramic precursor which can be used in the step, in the case of ceramic, silica, for example, there are such as TEOS (tetraethoxysilane), TBOS (tetrabutyl orthosilicate), TMOS (teramethoxysilane), SiCl 4 (tetrchlorosilane), the ceramic is TiO ₂ Titanium (IV) butoxide, titanium (IV) isopropoxide, titanium (IV) chloride, and the like If the SnO ₂ may include tin chloride (IV) (tin (IV) chloride), tin (IV) tert- butoxide (tin (IV) tert -butoxide) , when the ceramic is ZnO ₂ is acetic acid zinc (zinc acetate), (and the like, zinc chloride), if ZrO ₂ is zirconium (IV) tert- butoxide (zirconium (IV) chloride, zinc tert -butoxide), zirconium (IV) chloride (zirconium (IV) chloride), zirconium (IV) ethoxide (zirconium (IV) ethoxide), zirconium (IV) propoxide (zirconium (IV) propoxide).

When using a ceramic precursor, for example, TEOS (tetraethyl orthosilicate, 98%), which is a silica precursor, the mesoporous carbon structure template into which TEOS is injected is either HCl / H ₂ O vapor or NH ₄ OH / H ₂ O vapor. The TEOS is converted to silica by hydrolysis through the reaction with 50 to 100 ° C. or by exposing the sample to air at room temperature. As the ceramic precursor, precursors such as titanium (IV) alkoxide, tin (IV) alkoxide or zirconium (IV) alkoxide are converted to ceramic under the above conditions. When SiCl ₄ and TiCl ₄ are used as ceramic precursors, the ceramic precursors are deposited in a vapor phase and then reacted with moisture in the air to be converted into ceramics. Precursors, such as zinc acetate or zinc chloride, are dissolved in a solvent and injected into the mesoporous of the mesoporous carbon structure mold, and the temperature is raised to 5,500 / min in an inert gas (nitrogen) atmosphere in a tube furnace, and the temperature is increased to 550, In this condition, it is maintained for 3-4 hours to convert to ceramic.

In the process of injecting the ceramic precursor into the mesopores of the mesoporous carbon structure mold, the mixture of the mesoporous carbon structure mold and the ceramic precursor mixture is placed in a vacuum reaction vessel and maintained in a vacuum state for 2 to 3 hours to maintain the air in the mesopores of the carbon mold. At the same time, the ceramic precursor solution is injected into the pores of the mold, and dried inert gas (N ₂ or Ar) is injected into the vacuum reactor to prevent the conversion of the ceramic precursor into the ceramic by the moisture in the air. The carbon template and the ceramic precursor mixture are centrifuged to remove excess silica precursor.

For example, when the ceramic is silica, the carbon template-silica composite is heated to 550 ° C. in 1 ° C./min in a tube furnace under an air atmosphere, and heated at 550 ° C. for 6 hours to remove the carbon molds and thus the meso Porous silica (HUM-1: Hannam University Mesostructrue-1) is prepared. At this time, when the carbon template is removed, a small amount of the composite should be heat-treated to enable uniform heating to prevent the formation of fumed silica due to local overheating by the oxidation of carbon. That is, the thickness of the composite to be heat-treated should be as thin as possible, but if the pipe is rotatable, even more heat treatment may be possible to more uniform heating.

Step 5: Fabrication of a new mesoporous carbon structure based on a mesoporous ceramic structure (HUM-1)

As described above, a mesoporous ceramic structure composed of various ceramics may be manufactured using various ceramic precursors, but HUM-1, which is ceramic, is used as the mold of the second and third steps, and another ceramic precursor is used. It is also possible to obtain HUM-1 having the same structure made of different ceramic materials by repeating the second to fourth steps using in the third step.

Hereinafter, the configuration and effects of the present invention will be described in more detail with reference to specific examples, but these examples are only intended to more clearly understand the present invention and are not intended to limit the scope of the present invention.

Example 1 Preparation of Mesoporous Carbon Structure with New Crystal Structure

1) Preparation of mesoporous silica template

The mesoporous silica mold (M48T) required for the preparation of the mesoporous carbon mold is manufactured by Ryoo, R., Joo. SH, Kim, JH J. Phys. Chem. The method disclosed in B 1999, 103, 7435 was used. Cetyltrimethylammonium bromide (C ₁₆ H ₃₃ N (CH ₃ ) ₃ Br; CTMABr) and Brij ^™ (C ₁₂ H ₂₅ (OCH ₂ CH ₂ ) _n OH, n ≒ 4) were used as template and as silica source Ludox HS40, a colloidal silica, was used. The synthetic solution was made basic using sodium hydroxide (NaOH). The molar ratio of the template, silica source, sodium hydroxide and water was 5.0 SiO ₂ : 0.85 CTMABr: 0.15 Brij ^TM : 2.5 NaOH: 400 H ₂ O, stirred at room temperature for 30 minutes, and reacted at 100 ° C. for 48 hours. Cooled down. The pH of the cooled reactant was adjusted to pH 10 using an aqueous 30 wt% acetic acid solution, followed by further stirring at room temperature for 20 minutes and then reacting at 100 ° C. for 48 hours. After completion of the reaction, the precipitate was cooled to room temperature, the precipitate was filtered, washed with distilled water, and dried at 100 ° C. for 12 hours to obtain mesoporous MCM-48 silica. The MCM-48 containing the surfactant was dried at only 100 ° C., AM48T, and then 100 ml of 0.1 M HCl / EtOH solution per 1 g of dried MCM-48 silica was stirred at room temperature for 6 hours, followed by filtration, After washing with EtOH (95%) solution, WM48T was dried at 100 ° C. for 12 hours. The dried MCM-48 silica was calcined at 540 ° C. for 6 hours to obtain a mesoporous CM48T template. In this way, all three different pretreated mesoporous silica templates were prepared.

Curve a of FIG. 2 shows PXRD pattern (powder X-ray diffraction pattern) of CM48T among the three mesoporous silica templates (M48T) prepared in Example 1-1), and the results shown in the reported manufacturing method Is consistent with

2) Preparation of Mesoporous Carbon Structure Using Divinylbenzene as Precursor

When divinylbenzene is used as the carbon precursor, azobisisobutyronitrile (2,2'-azobisisobutyronitrile), which is a divinylbenzene and a radical initiator, is used in the mesoporous silica template (M48T) mesoporous prepared in Example 1-1; AIBN, 98%) The mixture (molar ratio; 25 divinylbenzene: 1 AIBN) is injected as follows. AIBN solid as a radical initiator was dissolved in divinylbenzene solution (80%) to prepare a clear liquid, and solid mesoporous silica was added to the solution. The mixture was placed in a vacuum vessel, depressurized to 0.2 mmHg, filled with nitrogen gas into a vacuum vessel under reduced pressure, and centrifuged for 30 minutes in a 1500 rpm centrifuge to remove excess divinylbenzene and AIBN, followed by gel mesoporous silica. The mold, divinylbenzene and AIBN mixtures were reduced to 0.2 mm Hg. The divinylbenzene polymer-M48T composite was prepared by polymerization at 70 ° C. for 12 hours under reduced pressure. The prepared composite was heated in a tube furnace at a temperature of 5 ° C./min in a nitrogen atmosphere for 7 hours in a temperature range of 900˜1000 ° C. to carbonize the divinylbenzene polymer to obtain a carbon-M48T composite. 1 g of the prepared carbon-M48T composite was dispersed in 40 ml of distilled water, and then 10 ml of 50 wt% HF solution was added thereto, and stirred at 25 ° C. for 12 hours to remove the silica mold portion, and the mesoporous carbon structure (M48T-C ) Was obtained by filtration, washing and drying.

Curve b of Figure 2 shows the PXRD pattern of the mesoporous carbon template (M48T-C) prepared by using the divinylbenzene polymer as a carbon precursor in Example 1-2), the results shown in the reported manufacturing method Is consistent with

3A is a transmission electron microscope (TEM) photograph of the mesoporous carbon template (M48T-C) prepared above.

The mesoporous carbon structure (M48T-C) prepared using mesoporous silica template (M48T) has a different structure from the mesoporous silica template (MCM-48) used as a template, and the results are consistent with the reported results. Suk Bon Yoon, Jeong Yeon Kim and Jong-Sung Yu, Chem. commun. , 2002 , 1536.]

3) Preparation of mesoporous carbon structure using phenol resin as precursor

When phenol resin is used as the carbon precursor, an acid catalyst is required for the polymerization of monomers. To this end, the prepared CM48T mold was first dried at 150 ° C. for 12 hours, and then dried. 1 g was added to an aqueous solution of AlCl ₃ (0.34 g) dissolved in 10 ml of ethanol (95%), stirred for 30 minutes, filtered, and dried in an oven at 150 ° C. When the dried CM48T silica mold was calcined at 500 ° C. for 4 hours in the air, aluminum (Al) ions were implanted on the silica surface and added to the silica surface, and the added aluminum (Al) gave the silica surface. Acidic sites are formed in the. After forming the acid site on the surface of the CM48T aluminosilicate thus formed, 99 wt% phenol was added, and the mixture was put in a vacuum glass reaction vessel, reduced to 0.3 mmHg, heated at 140 ° C. for 12 hours, and 95 wt% of formaldehyde was added. It heated at 120 degreeC for about 6 hours. Phenol and formaldehyde used above were 0.20 g and 0.16 g for 1 g of CM48T template, respectively. Phenol resin-CM48T aluminosilicate template complex was polymerized by polymerizing a polymer precursor by raising the temperature to 160 ° C. by raising the temperature by 1 ° C./min in a nitrogen atmosphere in a tube furnace in a tube furnace. The composite was prepared in a tube furnace under an inert gas (nitrogen) atmosphere by raising the temperature by 5 ° C./min in order to raise the temperature to 900-1000 ° C., and maintaining the above conditions for 7 hours to obtain carbon-CM48T aluminosilicate. A template complex was obtained. After dissolving 1 g of the carbon-CM48T aluminosilicate template complex in 40 ml of distilled water, 10 ml of 50 wt% HF solution was added thereto, and stirred at 25 ° C. for 12 hours to remove the silica mold portion, and the mesoporous carbon template was removed. Obtained by filtration, washing and drying.

Example 2 Preparation of Mesoporous Carbon Template and Silica Composite

The composite was prepared by injecting a silica precursor into the mesopores of the mesoporous carbon template prepared in Examples 1-2) and 1-3) and sintering. The mesoporous carbon template (M48T-C) prepared in the above example was dried in a vacuum oven at 12 ° C. for 12 hours, and then injected with a silica precursor tetraethoxysilane (TEOS; 98%) solution. Specifically, the mixture of 1 g of M48T-C and 5 ml of TEOS is placed in a vacuum reactor and kept at a reduced pressure of 0.2 mmHg for 2 hours to remove air present in the carbon template (M48T-C) mesoporous and at the same time TEOS ( 98%) and the solution is injected into the pores of the mold. The dried inert gas (N ₂ ) was injected into the vacuum reaction vessel, and the TEOS mixture was removed by centrifugation of the carbon template (M48T-C) and the TEOS mixture. The mesoporous carbon-silica composite was prepared by hydrolyzing the silica precursor using a method in which the TEOS-infused carbon template was reacted with HCl / H ₂ O steam at 100 ° C. for 24 hours.

Example 3 Preparation of Mesoporous Silica Structure (HUM-1) with New Structure

5 g of the mesoporous carbon-silica composite prepared in Example 2 was heated to 550 ° C. at 1 ° C./min in a tube furnace under an air atmosphere, and heated at 550 ° C. for 6 hours to remove the carbon template, thereby reducing mesoporousness. A silica structure (HUM-1) was prepared. At this time, when the carbon template was removed, a small amount of the composite was heat-treated to prevent the formation of fumed silica due to local overheating by oxidation of carbon.

Curve c of Figure 2 shows the PXRD pattern of the silica structure (HUM-1) prepared above, it can be seen that the new structure different from the mesoporous silica template structure (M48T), there will be a very regular mesopore It can be predicted.

3B is a transmission electron microscope (TEM) photograph of the silica structure HUM-1 prepared above, and it can be seen that mesopores are regularly arranged.

FIG. 4 shows nitrogen adsorption isotherms and corresponding pore size distribution curves of mesoporous CM48T, CM48T-C and mesoporous HUM-1 structures having a novel structure prepared in Examples 1-3. FIG. curves). Silica structure prepared in Example 3 can be seen that the material having a structure different from the CM48T, CM48T-C used as a template through the nitrogen (N ₂ ) adsorption-desorption curve. On the other hand, the adsorption isotherm of the M48T-C-silica composite of Figure 4 is flat even without the adsorption of nitrogen even if the pressure of nitrogen increases, it can be confirmed that the silica filled in the mesopores of M48T-C.

Example 4 Preparation of Mesoporous Carbon Structures Based on Mesoporous Silica Structures (HUM-1)

A second generation mesoporous carbon was prepared in the same manner as in Examples 1-2) and 1-3) using the mesoporous silica structure (HUM-1) prepared in Example 3 as a template.

5 is a transmission electron microscope (TEM) photograph of the mesoporous carbon structure prepared above, and it can be seen that mesopores are regularly arranged.

Applicability of the mesoporous silica structure (HUM-1) having a new structure as in Example 4, as well as use as a template, it is possible to introduce a metal such as Al, Ti, etc. into the adsorbent, the structure itself, and the structure The structure in which the metal is introduced can be utilized as a new catalyst because it can be exchanged with various transition metals.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. Referring first to FIG. A mesoporous silica mold (M48T) is prepared by using an organic template (surfactant) and silica, and the M48T-carbon is obtained by polymerizing and carbonizing a carbon precursor in an in-situ manner. A composite was prepared, and the silica portion was removed by etching to prepare a mesoporous M48T-carbon structure, which was then used as a template to inject a ceramic precursor into the mesopores, converted to ceramic, and then removed carbon to remove the mesoporous ceramic structure ( HUM-1) is prepared.

Figure 2 shows the PXRD pattern of the mesoporous silica template (a), mesoporous M48T-carbon structure (b) and mesoporous silica structure (HUM-1) (c) prepared through the above process. Referring to FIG. 2, first, the mesoporous silica template (M48T) shows a strong peak 211 at 2θ = 2.35 ° (see curve a), while the mesoporous M48T-carbon structure has 2θ = 1.62 ° and 2θ = 2.35. The two strong peaks 110 and 211 of approximately the same intensity are shown at degrees (see curve b), and the mesoporous silica structure (HUM-1) shows one strong peak 110 at 2θ = 1.64 ° and 2θ = 2.74. One weak peak 211 is shown at ° (see curve c). This makes it possible to know that the phase transition of the structure occurred during the preparation of the mesoporous silica structure (HUM-1) from the mesoporous silica template (M48T). Specifically, the crystal structure of the cubic M48T template with Ia3d space group was transferred to the new cubic mesoporous silica structure with I41 / a space group. This phase transition is believed to be due to a change in the relative position of the non-interconnected mesoporous channels of the two mirror image relationships. This change is believed to minimize energy in the process of removing the silica backbone. In addition, it can be seen from the curve c of FIG. 2 that the HUM-1 is an alignment structure having mesopores periodically well aligned. The intensity of the peak was obtained by integrating the area under the curve (AUC) from 2θ = 1.2 ° to 2θ = 7.0 °, where the AUC of HUM-1 is over 90% of the AUC of M48T, which is sequential. Despite the copying process, the integrity of the template is maintained.

3A and 3B show TEM images of the M48T-carbon structure and HUM-1, respectively, and FIG. 3B shows very well aligned periodically, with uniform pore and wall distribution, similar to HUM-1 with M48T-Taso structure. Shows that it has a structure. This is also consistent with the interpretation via the XRD pattern of FIG. 2.

4 shows nitrogen gas adsorption isotherms of M48T silica templates (■), mesoporous carbon structures (M48T-C) (●), and corresponding carbon-silica composites (▲) and HUM-1 (◆) and corresponding Pore size distribution curves of carbon (M48T) -silica template (■), mesoporous carbon structure (M48T-C) (●), and HUM-1 (◆). The black filled line represents the adsorption line and the unfilled line represents the desorption line. Adsorption tests were measured using a Micrometritics ASAP 2000 gas adsorption analyzer at 77 K after each sample was degassed at 4 μL for 6-6 hours at 20 μTorr at 423 K. The corresponding pore size distribution is calculated from the adsorption isotherm using the Barrett-Joyner-Halenda method.

Except for the carbon-silica complex, the measured isothermal curves can be classified as type-IV, according to the IUPAC nomenclature, which characterizes mesoporous solids. The carbon-silica composite shows a nearly flat adsorption isotherm curve, which shows that the pore volume and surface area are relatively very low. The composite was also found to consist of 58-63 wt% silica and 37-42 wt% carbon. This indicates that about 75 to 83% of the mesopores in the carbon structure is filled with silica as compared to the amount of silica calculated based on the pore volume of the mesoporous carbon structure and the amorphous silica density of 2.2 g / cm ³ . This is consistent with about 20% observed in CM48T-carbon. On the other hand, it can be seen that the adsorption isotherm curve of HUM-1 is significantly different from that of other structures.

The BET surface area of HUM-1 was 472m ² / g, which was found to be about half of the other structures. The pore volume of HUM-1 was 1.25 mL / g, which was confirmed to be almost the same as that of M48T. On the other hand, the average pore size of HUM-1 is 4.2 nm, which is much larger than the 2.8 nm and 1.9 nm of other structures.

The above results are summarized in the table below.

Sample d-spaced (nm) Unit cell parameter (a ₀ ) (nm) BET surface area (m ² / g) Total Pore Volume (mL / g) Pore size (nm) M48T 3.76 9.21 1082 1.21 2.78 M48T-C 5.46 7.72 1100 0.94 1.88 HUM-1 5.38 7.61 472 1.25 4.21

After pretreatment of various cubic crystalline MCM-48 structures that show the structural characteristics of mesopores that are three-dimensionally developed without being connected to each other like two enantiomers, a mesoporous carbon structure having a new structure as a template Was prepared, using a synthesized mesoporous carbon structure (M48T-C) as a mold again, injecting a ceramic precursor into the mold mesoporous, converting the precursor into a ceramic, and then removing the mold, a mesoporous ceramic having a new crystal structure. The construct (HUM-1) was prepared. The mesoporous ceramic structure having the new crystal structure prepared in the present invention can be applied to various applications such as a catalyst, a separator, a desorbent, a water purifier, an adsorbent, a membrane material, a sensor, a storage agent, as well as an application to a mold. have.

1 is a carbon template (M48T-C, mesoporous carbon structure) was prepared using a mesoporous silica template (M48T-carbon composite) obtained from a mesoporous silica template (M48T), and this carbon template was used in the present invention. According to the new crystal structure of the mesoporous ceramic (silica) structure (HUM-1) is shown schematically.

Figure 2 is a (c) a CM48T silica template, (b) a CM48T-C carbon template and a new structure prepared using the carbon template among the mesoporous material (M48T) synthesized for use as a template in the present invention (c) PXRD patterns (powder X-ray diffraction patterns) of the HUM-1 mesoporous silica structure.

3 is a transmission electron microscope (TEM) photograph of (a) mesoporous carbon structure and (b) HUM-1 mesoporous silica structure of novel crystal structure used as a template in the present invention.

4 is nitrogen (N ₂ ) of mesoporous silica template (M48T), mesoporous carbon-silica composite, mesoporous carbon structure (M48T-C) and mesoporous HUM-1 structure having a novel structure synthesized according to the present invention. Adsorption isotherms and corresponding pore size distribution curves are shown.

FIG. 5 is a transmission electron microscope (TEM) photograph of a second generation mesoporous carbon structure prepared using a mesoporous HUM-1 silica having a new structure synthesized according to the present invention.

6 is a diagram schematically showing a unit structure of a mesoporous silica template used in the practice of the present invention.

Claims (8)

It is made from mesoporous silica molds that have uniformly mesoporous channels of three-dimensionally partially interconnected nanostructures that are periodically aligned, and have a pair of mesoporous channels in an uninterconnected mirror image relationship. The mesoporous ceramic structure of the cubic structure having a new crystal structure, characterized by having a different crystal structure. The method of claim 1, wherein the silica template has a diameter of about 2-3 nm and has a pair of mesoporous channels of non-interconnected mirror images, exhibiting a strong XRD peak at 2θ = 2.35 °, and forming the new crystal structure. The mesoporous ceramic structure having a diameter of about 4-4.5 nm has a highly periodically aligned three-dimensional, partially interconnected, uniform mesoporous channel of nanostructures and 2θ = 1.64 °, which was not present in the original silica template. A mesoporous ceramic structure with a cubic structure having a new crystal structure, characterized in that it exhibits a weak XRD peak at 2θ = 2.74 °, which is a position corresponding to one strong XRD peak and a peak present in the original silica template. a) preparing a mesoporous silica template (M48T); b) preparing a silica-carbon template composite (M48T-carbon composite); c) preparing a mesoporous carbon structure (M48T-C); And d) A method for producing a cubic mesoporous ceramic structure having a new crystal structure according to claim 1, comprising the step of producing a mesoporous ceramic structure (HUM-1). The method of claim 3, a) preparing a mesoporous silica template (M48T) from an organic surfactant and a silica source; b) injecting a carbon precursor into the mesopores of the mesoporous silica template of step a) and carbonizing to produce a silica-carbon template composite (M48T-carbon composite); c) preparing a mesoporous carbon structure (M48T-C) by etching the silica-carbon template composite to remove silica; And d) preparing a mesoporous ceramic structure (HUM-1) by injecting a ceramic precursor into mesopores of the mesoporous carbon structure, converting the ceramic precursor into a ceramic, and calcining and removing carbon. To produce a cubic mesoporous ceramic structure having a new crystal structure according to claim 1. The method of claim 4, wherein the carbon precursor is divinylbenzene, acrylonitrile, vinyl chloride, vinyl acetate, styrene, methacrylate, methyl methacrylate, ethylene glycol dimethacrylate, urea, melamine Or a monomer such as CH ₂ = CRR ′ (where R and R ′ represent an alkyl group or an aryl group) to azobisisobutyronitrile (AIBN), t-butyl peracetate, benzoyl peroxide ( BPO), acetyl peroxide, or polymers prepared by addition polymerization using lauryl peroxide initiators, phenol-formaldehyde, phenol, furfuryl alcohol, resorcinol Polymer or mesophase pitch prepared by condensation polymerization of monomers such as formaldehyde (RF), aldehyde, sucrose, glucose or xylose with an acid catalyst such as sulfuric acid or hydrochloric acid pitch), and Ceramic precursors include tetraethoxysilane (TEOS), tetrabutyl orthosilicate (TBOS), silica precursors of teramethoxysilane (TMOS) or tetrachlorosilane (SiCl ₄ ), titanium (IV) butoxide, titanium (IV) isopropoxide (Titanium (IV) isopropoxide) and TiO ₂ precursors, titanium (IV) chloride, tin (IV) chloride and tin (IV) tert-butoxide (tin (IV) ) tert -butoxide) of SnO ₂ precursor, zinc acetate (zinc acetate) and zinc chloride (zinc chloride) of ZnO ₂ precursor, zirconium (IV) t- butoxide (zirconium (IV) t -butoxide), zirconium (IV) ZrO ₂ precursors, which are selected from zirconium (IV) chloride, zirconium (IV) ethoxide and zirconium (IV) propoxide, A cubic mesoporous ceramic structure having a new crystal structure according to claim 2 or 2 is prepared. How to. The carbon precursor is a polymer obtained by addition polymerization of divinylbenzene with an azobisisobutyronitrile (AIBN) initiator or a polymer obtained by condensation polymerization of phenol and formaldehyde with AlCl ₃ as an acid catalyst, and the ceramic precursor is silica. Method for producing a cubic mesoporous ceramic structure having a new crystal structure according to claim 1, characterized in that the precursor is TEOS. The silica-carbon template complex of step b) is etched with hydrofluoric acid (HF) solution, sodium hydroxide (NaOH) or potassium hydroxide (KOH) solution to remove silica used as a template, and the TEOS Is a cubic structure mesoporous ceramic having a new crystal structure according to claim 1 or 2, characterized in that the silica precursor is hydrolyzed and converted to silica by reacting with HCl / H ₂ O steam for 24 hours. A method of making a structure. The method according to any one of claims 3 to 7, wherein e) the mesoporous ceramic structure (HUM-1) is used as a mold and a ceramic precursor different from the ceramic precursor used in any one of claims 3 to 7 is used. The method of manufacturing a cubic mesoporous ceramic structure having a new crystal structure according to claim 1, further comprising repeating steps b) to d).