KR20080104097A - Metal-supported porous inorganic material and its manufacturing method - Google Patents

Abstract

The present invention relates to a porous material prepared by crosslinking nanoparticles of a metal, metal oxide alone or a metal-metal oxide composite form between layers of swellable clay lattice, and a method of manufacturing the same. It is high, the metal and metal oxide catalyst in the pupil is uniformly distributed, and the aggregation of the catalyst is effectively prevented to provide a novel porous material that can be effectively applied to the separation of harmful gases, volatile organic matter, toxic gas, adsorption, decomposition.

Description

Metal-loaded porous inorganic materials and the preparation the same}

FIG. 1 shows X-ray diffractogram measurement results of room temperature drying and 2-hour heat treatment samples of SiO ₂ -Fe ₂ O ₃ crosslinked clay prepared in Example 1 at room temperature.

FIG. 2 is a microcavity distribution curve of a sample obtained by heat-treating SiO ₂ -Fe ₂ O ₃ crosslinked clay prepared in Example 1 at 400 ° C. for 2 hours. This curve is the result of calculation using the MP (micropore) method using nitrogen desorption isotherm. The square curve is the result calculated using the adsorption isotherm.

3 is a result of measuring the susceptibility change according to the change of the magnetic field at each measurement temperature of the sample synthesized in Example 1 heat-treated at 400 ℃ for 2 hours using a superconducting quantum interference device (SQUID).

4 is a nitrogen adsorption-desorption isotherm of a sample obtained by heat-treating SiO ₂ -Fe ₂ O ₃ crosslinked clay prepared using the synthetic mica of Example 4 at each temperature for 2 hours.

5 is a nitrogen adsorption-desorption isotherm of SiO ₂ -Fe ₂ O ₃ crosslinked clay synthesized while varying the type of organic template.

FIG. 6 is an X-ray diffraction pattern of porous crosslinked clay subjected to reduction treatment for 2 hours at each temperature by Example 8. FIG.

7 is an ultraviolet-visible absorption spectrum of the samples synthesized in Examples 1 and 8. FIG.

8 is a graph showing adsorption-desorption isotherms of toluene, which is a volatile organic matter of the samples synthesized in Examples 1 and 8. FIG.

9 is a result of measuring the carbon monoxide (CO) adsorption rate with time of the sample (SFM-H ₂ -400) synthesized in Example 8 by infrared spectroscopy.

10 is a result of measuring the ammonia removal rate over time of the sample synthesized in Example 8 (SFM-H ₂ -400).

The present invention relates to a porous material used for separating, adsorption removal and decomposition removal of harmful gases causing air pollution, and more particularly, to specific hazardous gases such as ammonia, sulfur compounds, carbon monoxide, boilers, etc. Dioxins, carbon monoxide, volatile organics from power plants, incinerators, etc.Hazardous exhaust gases such as NO _x , CO _x and SO _{x from} automobiles and ships, Acid and basic gases in semiconductor process clean rooms, Toxic suffocating gases from fire sites, The present invention relates to a porous material used to remove various harmful gases such as toxic gases during terrorism or war, and a method of manufacturing the same.

In the past, various materials and technologies have been developed to separate, adsorb, and decompose harmful gases. For example, in order to remove nitrogen oxides in exhaust gas, catalysts prepared by reacting precious metals such as Pt, Pd and Rh or transition metals such as V, Fe, Co and Cu with titanium dioxide, vanadium oxide, alumina and zeolite are durable. It has been used in combination with a substrate such as honeycomb cordierite, which is strong and breathable, or made into a particulate and filled in a catalyst tower. However, in this prior art, the cost of preheating equipment (250 to 350 ^o C) and additional energy costs for the activation of the catalyst, the storage and management burden of general reducing ammonia gas, the installation cost of ammonia monitoring released into the atmosphere, and excess ammonia It has been pointed out that a separate equipment cost for removing the catalyst, a large pressure loss when using a particulate catalyst, lack of economics due to the use of precious metals, deterioration of efficiency due to agglomeration of the catalyst during use, performance degradation during recycling. For example, Korean Patent Publication No. 1998-015401 discloses the preparation of a denitration catalyst using a zeolite containing cobalt metal and alkaline earth metal, and US Pat. The material is disclosed as a catalyst for removing nitrogen oxides. Iwamoto et al. Also reported on selective reduction catalysts using hydrocarbons using Cu ²⁺ -ZSM-5 materials (Iwamoto M, Mizuno N, Yahiro H, Sekiyu Gakkashi, 1991, 34, 375). Decreased activity in the atmosphere and poor high temperature heat resistance are known problems. In addition, Korean Unexamined Patent Application Publication No. 2002-0051885 discloses a method for removing nitrogen oxide using a material made by supporting natural manganese and metal ions on a honeycomb or a sheet metal support, and in US Pat. No. 5,827,489, V, Mo on titania, alumina, silica, and zirconia carriers. A selective catalytic reduction method (SCR) carrying active metal oxides such as Ni, W, Fe, and Cu is disclosed. In addition, Korean Unexamined Patent Application Publication No. 2003-0096062 discloses an exhaust gas purification filter catalyst in which a catalyst is supported on a ceramic honeycomb, and Korean Unexamined Patent Application Publication No. 2005-009807 discloses a diesel oxidation catalyst device in which a ceramic carrier and a metal carrier are combined. It is starting. Korean Patent Application Laid-Open No. 2006-0056530 discloses a method for preparing a catalyst filter for automobile exhaust gas purification by coating a noble metal and catalyst oxide on a ceramic honeycomb carrier. The removal catalyst is disclosed, and Korean Unexamined Patent Publication No. 2005-0030223 discloses an exhaust gas purification filter using metal fibers.

On the other hand, chemical filters or ion exchange fibers made of impregnated activated carbon are generally used to purify acidic gases such as HF, SOx, and NOx, and basic gases such as ammonia and amines in places requiring high cleanness, such as in clean rooms of semiconductor factories. Has been. However, these chemical filters have problems such as volatilization of gaseous organic substances from binders, adhesives, and seal materials used to process filter units, gas generation problems when using urethane foam, limitations in removal performance, and pressure loss. It has been pointed out. In order to overcome the problem of the chemical filter, Korean Laid-Open Patent Publication 2001-0021830 discloses the purification using a porous inorganic adsorbent. In another method of purifying ammonia, Korean Unexamined Patent Publication No. 200-0004660 uses Co., V, Mo, W, Cu, Ni, Fe and other transition metals using ceramic honeycomb, ceramic foam, metal foam, silica, alumina, and zeolite-supported adsorbent. A method is disclosed. As another method, U.S. Patent 4,179,407 proposes a method of converting nitrogen and water by oxidatively decomposing ammonia with a metal catalyst below 300 ^° C.

On the other hand, there are techniques for removing aromatic halogen compounds such as dioxins using high pressure discharge facilities, plasmas, oxidation catalyst towers, etc., but all have problems of expensive installation cost, maintenance cost, and operation technology. Most used. In Korean Patent Application Laid-Open No. 2002-0009353, a porous organic-inorganic composite is prepared by treating activated carbon or activated carbon fibers with silica or alumina, followed by coating a metal salt or metal oxide, and aromatics such as nitrogen oxides and dioxins using a composite catalyst obtained by complexing a reducing agent. Disclosed is compound removal. In addition, Korean Unexamined Patent Application Publication No. 2006-0123680 discloses a catalyst for dioxin removal by coating a metal-based porous foam or ceramic filter with a Ti-A-B composite catalyst composed of a Ti-Pt group metal and a lanthanide-based metal.

In addition, porous inorganic materials have been used to adsorb and remove volatile organic compounds. Korean Patent No. 2007-0686371 discloses a mixture of natural jade, ganban stone, zeolite and titanium dioxide to reduce volatile organic compounds and formaldehyde, and Korean Patent No. 2007-0704128 including volatility using noble metals and transition metals. A nanocatalyst for removing organic compounds is disclosed, and US Patent 5,506,188 discloses a VOC removal mainly composed of activated carbon and zeolite.

In addition, activated carbon or impregnated activated carbon is generally used as an adsorption material for harmful and odorous substances, such as an emergency evacuation fume mask for military evacuation and a poison gas purification for military gas masks. In most cases, powder activated carbon is attached to a thin nonwoven fabric or applied between nonwoven fabrics to form a layer of activated carbon that is too thin, so that the adsorption efficiency decreases and organic compounds or adhesive components are used in the process of applying activated carbon to the nonwoven fabric. As the substance adheres, the adsorption function of the original activated carbon is reduced. In addition, in order to improve the adsorption efficiency, the method of filling activated carbon or potassium permanganate into the attached cylindrical purifier can be used. In this case, it is effective at relatively low concentration. However, the problem of low efficiency at high concentration and deterioration of adsorption performance at long term storage is pointed out as a problem. It is becoming. For example, Korean Unexamined Patent Publication No. 95-14813 is prepared in the form of a cartridge or a block using deodorizing material of activated carbon containing at least one metal oxide such as iron, chromium, nickel, cobalt, manganese, copper, copper, and magnesium. One deodorant is disclosed. However, the deodorant of such a formulation is weak in strength due to its weak strength, and the deodorant component is likely to fall off due to friction or physical impact. Therefore, the deodorant has been compounded as a deodorant formulation. Has been pointed out.

 As described above, it is known that a catalyst-supported porous material can be effectively used for separation, adsorption, and decomposition of harmful gaseous materials, and development of materials for achieving improved porosity and catalytic performance has been actively developed. For example, Korean Patent Laid-Open Publication No. 2002-0079398 and JP 2001-00104282 provide a metal catalyst in which a metal component is supported with high dispersion by reducing liquid phase of a metal halide compound using an organic base and a reducing agent. In addition, Japanese Patent Application Laid-Open No. 56-155634 and Japanese Patent Application Laid-Open No. 3-60534 disclose methods for preparing metal colloids first and immobilizing colloidal particles on a carrier. In this case, the manufacturing process is long, and extra polymer for colloid stabilization is disclosed. Problems have been pointed out such as the use of compounds, surfactants, and metal loading limits. As another method, a method of obtaining a metal supported catalyst by substituting and reducing metal ions in an ion exchange capacity carrier (PETROTECH Vol. 17, 1994, 441) has been proposed. However, in this case, too, the amount of supported metal is limited to the amount of ion exchange, and there is a limit of the supported amount, and there is also a problem that sintering of metal particles occurs during reduction. Meanwhile, Korean Unexamined Patent Application Publication No. 2004-0001372 discloses a method for preparing a porous adsorption filter material provided by mixing acrylic fibers with inorganic powders such as activated carbon, zeolite, clay and clay. In addition, Korean Unexamined Patent Publication Nos. 2004-0049278 and 2004-0049279 disclose a method for manufacturing a gas filter ceramic filter using ceramics such as silicon carbide, alumina, silimite, kaolin, silica, titania, and diatomaceous earth. -0089702 and JP 2001-00072354 disclose a method for producing a porous ceramic filter using hollow polymer particles.

The purpose of the present invention is to solve the problems of various conventional adsorbents and catalysts used to separate, adsorb and decompose harmful gases as described above. It is to provide a porous inorganic material cross-linked oxide nanoparticles and a method of manufacturing the same.

It is also an object of the present invention to provide porous adsorbents and catalysts in which the crosslinked metal and metal oxide catalysts are highly dispersed at the nanometer level. That is, the metal-supported porous crosslinked clay of the present invention immobilizes the metal or metal oxide particles having a size of 1 to 200 nm in the layered silicate lattice to form micropores between the silicate lattice and the metal or metal oxide crosslinked particles, thereby having a very high porosity. At the same time, a porous material capable of maintaining high dispersibility of the catalyst by preventing agglomeration of the nano-sized catalyst material in the material synthesis process, the component manufacturing process of the material, the adsorption and decomposition of harmful gas, and the regeneration process of the catalyst. It is to provide a manufacturing method.

Still another object of the present invention is to deposit metal nanoparticles on the surface of oxide nanoparticles such as silica, titania, and zirconia to maintain high dispersibility of catalytically active metal nanoparticles and to improve thermal stability of porous structure. And to provide a method for producing the same. It is also an object of the present invention to provide a pupil structure modification technology capable of arbitrarily controlling the size and structure of micropores between clay layers formed through crosslinking of metal or metal oxide nanoparticles.

It is also an object of the present invention to provide a sol and gel-like porous materials that can be effectively applied to carriers such as ceramic honeycombs, nonwoven fabrics, as well as powdery porous materials.

In addition, an object of the present invention is to provide a filter material that can efficiently separate, adsorb, and decompose harmful exhaust gases, acidic and basic gases, odors, toxic gases, and volatile organic compounds by using the metal-supported porous materials. .

The metal-supported porous material of the present invention is composed of a metal or metal oxide alone or a metal-metal oxide composite particle capable of exhibiting adsorption and catalytic activity, and a swellable clay material serving as a carrier to fix the same.

The metal or metal hydroxide which can exhibit adsorption and catalytic activity used in the present invention is not particularly limited, but the metal which can be inserted between the layers of clay is preferably alkali metal, alkaline earth metal, Ti, V, Cr, Mn , Fe, Co, Ni, Cu, Zn, Al, Ga, Si, Mo, W, Nb, Sn, Sb, Ir, Ag, Cd, Ru, Pt, Rh, Pd, Au, lanthanum metal and oxides thereof Included.

In addition, in the present invention, the metal and the metal oxide to another metal in order to improve the dispersibility of the metal and metal oxide catalyst, improve the thermal stability, inhibit the coagulation by sintering, improve the selectivity of the catalyst, specific surface area, pupil size and porosity Oxide (catalyst supported oxide) A complex catalyst complexed by depositing on the surface of nanoparticles can be used. At this time, the catalyst supported oxides include silica (SiO ₂ ), alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ), titania (TiO ₂ ), ceria (CeO ₂ ), chromium oxide (Cr ₂ O ₃ ), and iron oxides. (Fe ₂ O ₃ ) light, vanadium oxide (V ₂ O ₅ / V ₂ O ₃ ) light, manganese oxide (MnO ₂ / Mn ₂ O ₃ ) light, cobalt oxide (Co ₂ O ₃ , CoO) light, etc. Can be used.

As the clay material capable of immobilizing metal and metal oxide catalyst particles in the present invention, any clay having swelling property can be used without particular limitation. Therefore, in the present invention, swellable clay may be effectively used regardless of physical or chemical properties such as natural or synthetic, clay particle size, composition, and cation exchange capacity (CEC), but typically montmorillonite and hectorite. smectite clay, vermicullite, synthetic mica, kanemite, margotite, including hectorite, beidelite, saponite, etc. (magadiite), kenyanite and the like can be preferably used.

In the present invention, a method for preparing a metal-supported porous crosslinked clay includes the steps of preparing a crosslinked material, dispersing clay in a solvent, inducing an ion exchange reaction by mixing the crosslinked material and a clay dispersion, and then terminating the liquid. It consists of separation and repetitive washing steps, drying steps, and oxidation or reduction reactions through heat treatment.

First, the preparation of a crosslinking agent (pillaring agent) is used as an alkoxide compound or water-soluble salt of the metal or metal oxide of interest as a starting material, dissolved in water or a solvent and then used in the ion exchange reaction. At this time, if necessary, by adjusting the pH of the solution by adding a base or an acid to the metal ion solution, the metal ion species may be hydrolyzed to be suitable for intercalation and then an intercalation reaction may be performed. Known techniques can be used for the hydrolysis of metal ion species through pH adjustment of solutions (Pillared Clays, edited by R. Burch, Special Publication of Catalysis Today, 1988, 2, Elsevier Sci. Publ. BV, Amsterdam; Han YS, Journal of Solid State Chemistry 144, 45 (1999), Han YS, Chem. Mater. 9, 2013 (1997)). The crosslinking solution is preferably a clear solution or a colloidal dispersion.

Preparation of the clay dispersion can be easily obtained by weighing the required amount of clay into water, an organic solvent such as alcohol, or, if necessary, into a mixed solvent of water-organic solvent. At this time, the concentration of clay is preferably 1 to 10% by weight. If the concentration is less than 1% by weight, the solvent ratio is too high, and the process time in the subsequent separation and washing process is long, and the amount of waste liquid is increased, which is undesirable. If the concentration is more than 10% by weight, the process is effective due to the increase of viscosity due to swelling of clay. No progress is made.

The ion exchange reaction by mixing the prepared metal ion crosslinked material and the clay dispersion can be easily achieved using a known general process. The mixing ratio of the metal crosslinked material and the clay may be arbitrarily adjusted according to the amount of metal to be impregnated, but the ratio of 1 to 100 metal ion equivalents to the cation exchange capacity (CEC) of the clay is preferable. When the equivalent ratio is 1 or less, the metal ion concentration to be mixed is too low compared to the cation exchange capacity, so that an effective ion exchange reaction may not proceed, and as many metal particles as desired may not be intercalated, and when the equivalent ratio is 100 or more, Economical problems due to the use of crosslinking materials, large amounts of waste liquid, long washing processes are undesirable. In addition, the ion exchange reaction is preferably a temperature of 20 ~ 100 ^℃ , the reaction time is about 5 minutes ~ 24 hours. If the reaction temperature is 20 ^o C or less or the reaction time is 5 minutes or less, an effective ion exchange reaction cannot be achieved. On the contrary, if the reaction temperature is 100 ^o C or more or the reaction time is 24 hours or longer, Sedimentation may occur and there is a problem of inferior economics due to additional energy consumption and long process time.

Ion exchange of metal or metal oxide crosslinked material between clay layers or if necessary, organic template is used to induce the lamination of crosslinked material between layers by using organic template. It can be used as a method for arbitrarily adjusting the volume. When used during the ion exchange process, the organic template may be added to the solution together with the crosslinking material, and when added after the ion exchange, a separate organic matter treatment process may be added after the washing step is completed. At this time, the organic template that can be used is not particularly limited as long as it is an organic material that can be intercalated between the layers of clay to change the laminated structure of the cross-linking material, but cationic or neutral surfactants, natural or synthetic polymer materials are preferably used. Can be. Typically, amine-type surfactants such as hexadecyltrimethylammonium salt, octadecyltrimethylammonium salt, neutral surfactants such as polyoxyethylene glycol, natural polymer materials such as chitosan, and synthetic polymer materials such as polyvinyl alcohol are preferable. The amount of the organic template added to the reaction is preferably 5 to 100% by weight based on the total solids. If the content is less than 5% by weight, the interlayer structure deformation by the organic template cannot be effectively achieved. If the content is more than 100%, the substitution of the metal or the metal oxide crosslinking material is caused by the excessive intercalation of the organic material, so that the desired porous structure is removed after the template is removed. It is not possible to obtain it, and additional process generation and additional energy consumption for thermal decomposition of excess organic matter are problematic.

After the ion exchange reaction is completed, the next step involves separating and washing the product from the reaction solution. Separation of the product from the reaction solution can be used in any conventional manner without particular limitation, centrifugation method or membrane filter method may be preferably used. Washing is a step to remove excess acid, base, and crosslinking material used during the reaction. As a washing solvent, water, an organic solvent or a mixed solvent of water-organic solvent may be appropriately used depending on the characteristics of the system. Repeat until the impurities are 1% by weight or less.

The drying step of the reaction product may be used without particular limitation to the conventional drying method. Preferably oven heating drying, vacuum drying, spray drying may be used.

When the drying step is completed, the step of oxidizing the cross-linking material inserted between the layers through the heat treatment step to obtain an oxide or reduce to obtain a metal. First, an oxide corresponding to each metal ion may be formed through a heat treatment under an oxidation reaction atmosphere. In this case, the heat treatment condition during the oxidation reaction is preferably within 1 to 24 hours in a temperature range of 100 to 1000 ^o C. And the heat treatment temperature is formed of 100 ^o C or less in the case where the decomposition of the organic materials contained in the layers can be removable or crosslinked substances to be incorporated in the course of the reaction can not not enough metal oxide may not be smooth, if more than 1000 ^o C Clay Sintering of the lattice and interlayer crosslinking material occurs and the desired porous material cannot be obtained. In addition, when the heat treatment time is also within 1 hour, the intercalation or residual organic matters may not be sufficiently decomposed, and when the heat treatment time is 24 hours or more, agglomeration may occur due to sintering of the nano-sized metal or metal oxide particles formed between the layers. It is also undesirable from the viewpoint.

Similarly, when the crosslinked material is reduced by heat treatment to induce a metal corresponding to the crosslinked material, heat treatment is preferably performed in a reducing atmosphere such as hydrogen, nitrogen, carbon monoxide, helium, and vacuum. At this time, the heat treatment condition during the reduction reaction is preferably within 1 ~ 24 hours in the temperature range of 100 ~ 1000 ^o C. If the heat treatment temperature is less than 100 ^o C, the desorption of intercalated water mixed in the reaction process or the decomposition of organic materials contained in the crosslinking material are not sufficient, and the adequate activation energy required for reduction to the metal oxide metal cannot be supplied. Formation of the metal particles is not smooth, and in the case of more than 1000 ^o C sintering of the lattice lattice and interlayer crosslinking material occurs, the desired porous material can not be obtained. In addition, if the heat treatment time is less than 1 hour, the interlaminar water or residual organic matters may not be sufficiently decomposed, and reduction to metal may occur. If the heat treatment time is 24 hours or more, agglomeration may occur due to sintering of the nano-sized metal particles formed between the layers. It is not desirable economically. On the other hand, in order to achieve the formation of metal particles effectively, the above-described oxidation process and reduction process may be carried out continuously. That is, a method of first oxidizing the crosslinked material sufficiently by heat treatment in an oxidizing atmosphere and then heat treating in a reducing atmosphere may convert the metal oxide into a metal.

After completion of the heat treatment process may include the addition of a conventional grinding process to prepare a fine powdery porous material. At this time, the pulverization can be used without any known fine particle pulverization technology, ball-mill, jet-mill and the like can be preferably used. In addition, the manufacturing process of the granules using a fine powdery porous material may be additionally included. The manufacturing process of granules can also be used without a well-known method. In addition, a process of supporting the fine powdery porous material on a desired carrier may be additionally included and there is no particular limitation.

On the other hand, the process of supporting the porous material on the carrier includes a step of directly supporting or coating a porous precursor (sol) or gel (precursor) on the desired carrier obtained after the end of the washing process. That is, the sol or gel-like porous precursor obtained after the end of washing is ceramic honeycomb, metal honeycomb, ceramic foam, metal foam, ceramic film, metal film, polymer film, porous polymer, porous glass, porous ceramic granules or balls, ceramic fiber, After direct immersion, coating, and spraying techniques on glass substrates, metal fibers, activated carbon, carbon fibers, and non-woven foams, which are commonly used in the past, porous materials are formed through subsequent drying and heat treatment processes. A process for producing a supported carrier is included. The application of the carrier using a sol or gel-like porous precursor can shorten the process than the process of applying the fine powder to the porous material, and can avoid the use of additional chemicals, which is very economical. .

The metal-supported porous material obtained through the above manufacturing process first shows excellent porosity characteristics with a specific surface area in the range of 50 to 1000 m ² / g, and micropores or mesopores having a pore size in the range of 5 to 100Å. It contains micropores of the area and can arbitrarily control the type of catalyst, oxidation state, porosity, specific surface area and pupil size by changing the type of clay, type of crosslinking material, type or concentration of organic template, and reaction conditions. Characteristic, shape selectivity of the material can be imparted by controlling the size of the pupil, adsorption and catalytically active material is stabilized by the two-dimensional silicate lattice layer to achieve high dispersion of the catalyst, heating or hydrothermal method In the regeneration of materials by minimizing the agglomeration of catalyst particles can minimize the performance degradation, and metal and metal oxide nanoparticles Site is stabilized by a lattice structure or a supported metal oxide it has excellent thermal stability, it does not have a special device, such as a random number sequence has a synthesizer is required to manufacture a simple feature.

The metal-supported porous material obtained through the present invention includes ammonia and amine compounds, sulfur compounds, carbon monoxide, dioxins, volatile organic substances, nitrogen oxides, and sulfur oxides, which are harmful gases generated in industrial sites, automobiles, power plants, incinerators, boilers, fires and general households. It has a feature that can be effectively applied to the purpose of the adsorption removal and decomposition removal for the.

Hereinafter, specific examples of the present invention will be presented through examples. However, the following examples are only intended to show specific examples of the present invention, it should not be understood that the scope of the present invention is limited by the examples.

Example 1

Using montmorillonite (Kuntia G, Kunimine) as a natural clay, 5 g of clay is added to 500 mL of distilled water and dispersed by stirring for 2 hours. Meanwhile, in order to prepare silica nano sol-particles, 42.6 g of tetraethoxy orthosilicate (TEOS), 10 mL of 2N hydrochloric acid, and 12 mL of ethanol were mixed and vigorously stirred at room temperature for 2 hours to prepare silica nano sol particles. In the silica nanosol solution thus prepared Fe (NO ₃ ) ₃ ^. An aqueous solution of Fe ³⁺ prepared by dissolving 10.2 g of 9H ₂ O in 50 mL of distilled water is added while stirring. In this case, Fe ³⁺ ions are mainly deposited on the surface of the silica nanoparticles by the electrostatic attraction. The mixture was slowly titrated with 0.4N-NaOH aqueous solution while stirring to bring the pH of the solution to 2.7. At this time, Fe ³⁺ ions deposited on the surface form an oligomer of Fe _x (OH) _y ^{z +} form by hydrolysis. Thus prepared Fe _x (OH) _y ^{z +} -SiO ₂ type crosslinking material (pillaring species) is added to the aqueous clay solution previously dispersed with vigorous stirring. The ion exchange reaction between the crosslinked material and clay is carried out at 60 ° C. for 3 hours. After the ion exchange reaction is completed, the solid-liquid is separated using a centrifuge, and the remaining solid on the gel is washed three times using a mixed solvent in which water and ethanol are mixed in a 1: 1 volume ratio. Once the washing step is complete, the porous precursor on the gel may be obtained primarily. After washing, the gelled product was dried in an electric oven at 100 ° C. for 12 hours, pulverized and heat-treated at 200 to 900 ° C. in an air atmosphere for 2 hours to prepare a reddish brown SiO ₂ -Fe ₂ O ₃ crosslinked clay. 1 is an X-ray diffractogram after drying at room temperature and by heat treatment at different temperatures. Table 1 shows the specific surface area and pore volume of the porous crosslinked material heat-treated at a temperature range of 200 to 800 ° C. The results are shown. In addition, the pupil size distribution curve calculated by the MP method using the adsorption-desorption isotherm of nitrogen is shown in FIG. It can be seen that the SiO ₂ -Fe ₂ O ₃ crosslinked clay synthesized through the present examples from FIGS. 1 and 2 and Table 1 has excellent porosity and thermal stability. This large specific surface area and pore volume of the SiO ₂ -Fe ₂ O ₃ crosslinked clay synthesized through the present embodiment is such that nanooxide particles form a multi-layered lamination structure between silicate layers, and micropores of about 10Å are crosslinked. It was confirmed that the results are represented by the formation. In addition, the contribution of specific surface area (S _micro- ) and pore volume (V _micro- ) by micropores is predominant, and the porosity of crosslinked clay is mainly due to the development of micropores due to the insertion of nanoparticles between clay lattice layers. You can see what you did.

Table 1 Interlayer distance, specific surface area and pore volume of SiO ₂ -Fe ₂ O ₃ crosslinked clay

Calcination temp. (℃ / 2h) Basal spacing Surface area (㎡ / g) Pore volume (mL / g) BET S _micro- ^a S _meso- ^a Total V _micro- ^a 200 62.2 634 429 206 0.45 0.24 300 58.6 690 468 222 0.49 0.26 400 58.2 767 482 240 0.50 0.27 500 58.1 622 397 225 0.45 0.23 600 54.5 553 296 257 0.40 0.20 700 51.3 480 269 210 0.35 0.15 800 49.6 390 134 191 0.26 0.08

^a estimated by t-plot method.

Example 2

In the same manner as in Example 1, but the sol solution is prepared by changing the content of Fe to be added, and the crosslinking by using this as a crosslinking material for the effect of Fe content on the crosslinking reaction and the properties of the crosslinked clay Investigate. In this example, the Fe content was changed to 1.0, 5.0, and 15 in a Fe / Si molar ratio to prepare a sample. Table 2 shows the pore volume calculated from the nitrogen adsorption-desorption isotherm measurements for samples heat-treated at 400 ° C. for 2 hours. It can be seen from Table 2 that the specific surface area and the pore volume change according to the ratio of Fe addition, and the molar ratio of 5 shows excellent porosity characteristics. In addition, the results of elemental analysis for the same sample are shown in Table 3. It can be seen from Table 3 that the Fe content increases proportionally as the addition ratio of Fe increases.

[Table 2] Specific surface area and pore volume according to Fe / Si molar ratio in SiO ₂ -Fe ₂ O ₃ crosslinked clay

Mole ratio Surface area (㎡ / g) Pore volume (ml / g) [Fe] / [Si] S _BET V _total 1.0 638 0.43 5.0 767 0.50 15 438 0.33

[Table 3] of SiO ₂ -Fe ₂ O ₃ Crosslinked Clays with Various Fe / Si Molar Ratios Using ICP

Elemental analysis

Mole ratio Analytical results (mol%) Pillar composition a [Fe] / [Si] SiO ₂ Fe ₂ O ₃ Al ₂ O ₃ (SiO ₂ ) _x (Fe ₂ O ₃ ) _y x + y 1.0 77.1 6.5 13.7 5.74 0.37 6.11 5.0 74.6 9.5 12.9 5.99 0.62 6.61 15 71.0 13.8 12.7 5.65 0.89 6.54

^{a The} composition of the crosslinking material is calculated by assuming the basic formula of montmorillonite. [(SiO ₂ ) _x (Fe ₂ O ₃ ) _y ] [(Si _3.89 Al _0.11 ) (Al _1.69 Mg _0.32 Fe _0.08 )] O ₁₀ (OH) ₂ .

Example 3

The susceptibility of the sample synthesized in Example 1 heat-treated at 400 ° C. for 2 hours was measured using a superconducting quantum interference device (SQUID). 3 is a graph showing the change of susceptibility according to the change of magnetic field at each measurement temperature. It can be seen from FIG. 3 that the Fe ₂ O ₃ particles in the SiO ₂ —Fe ₂ O ₃ crosslinked clay have paramagentic properties, and the result shows that the Fe ₂ O ₃ particles in the crosslinked clay are nanometer in size. The results prove that the distribution is highly uniform.

Example 4

A porous material was prepared in the same manner as in Example 1 using a swellable synthetic mica (S1ME, COOP Chem.) As clay. Figure 4 shows the nitrogen adsorption-desorption isotherm for the sample heat-treated at 400, 600, and 800 ℃ dried sample for 2 hours. It was found that the sample heat-treated at 400 ° C showed the maximum porosity, and the shape of the isotherm showed the Type I curve in the IUPAC classification, which developed micropores as the nanoparticles cross-linked between layers. This proves that they have a form of porous structure. Information on specific surface area and pore volume calculated from nitrogen adsorption-desorption isotherm analysis is summarized in Table 4. The specific surface area of 550m ² / g, pupil volume up to 0.56mL / g was confirmed that the material with excellent porosity was synthesized. In addition, it can be seen that most of the specific surface area is derived from the micropores, which can be interpreted as that the particles of the nano-sized oxide form a multi-layered lamination structure between layers.

[Table 4] Synthesis of SiO ₂ -Fe ₂ O ₃ Crosslinked Clay (SFM) Using Synthetic Mica and Synthetic Mica

Specific surface area and pore volume by heat treatment temperature

Sample Surface area, ㎡ / g Pore volume, ml / g BET Lang. S _micro- ¹⁾ Total V _micro- ¹⁾ Mica-400 9.2 15.0 0 0.116 0 SFM1-400 388.7 598.0 346.7 0.289 0.182 SFM1-600 322.1 496.0 276.4 0.296 0.145 SFM1-800 55.4 90.7 22.2 0.133 0.012

¹⁾ Value calculated through t-plot analysis of adsorption isotherm.

Example 5

This example was carried out to verify the effect on the change of porosity when the organic template is processed during the ion exchange process. To this end, in the same manner as in Example 4, in the crosslinking process using the swellable synthetic mica, the crosslinking material (Fe _x (OH) _y ^{z +} -SiO ₂ ) is mixed with the mica dispersion to ion exchange reaction, and the gelled reaction product obtained after washing Each 1 g is dispersed again in a mixed solvent of 50 mL of distilled water and 50 mL of ethanol. Here n- octadecylamine _{(n-CH 3 (CH 2} ) 17 NH 2, NS), a quaternary ammonium salt, dodecyl trimethyl ammonium chloride ^{_{((CH 3) 3 N +}} (CH 2) 11 CH 3 Cl -, Q12) tetradecyl trimethyl ammonium chloride ^{_{((CH 3) 3 N +}} (CH 2) 13 CH 3 Cl -, Q14), hexadecyl trimethyl ammonium chloride ^{_{((CH 3) 3 N +}} (CH 2) 15 CH 3 Cl - , Q16), octadecyl trimethyl ammonium chloride ^{_{((CH 3) 3 N +}} (CH 2) 17 CH 3 Cl -, Q18) , and dimethyl distearyl ammonium chloride ^{_{((CH 3) 2 N +}} ((CH 2) 11 0.2 g of CH ₃ ) ₂ Cl ⁻ and DS) were added to dissolve each. It reacted at 60 degreeC for 12 hours, stirring strongly. After completion of the reaction, the reaction product was separated by centrifugation, washed three times using water and ethanol mixed solvent (1: 1 by volume), and dried in a vacuum oven at 100 ° C. for 12 hours to obtain a powdery substance. To get This was subjected to heat treatment for 4 hours while flowing oxygen in a 550 ° C. electric furnace to combust and decompose an organic material to prepare a porous crosslinked clay having a modified porous structure.

Example 6

The nitrogen adsorption-desorption isotherm of the porous crosslinked clay synthesized through Example 5 was measured at liquid nitrogen temperature (77K). Figure 5 shows the nitrogen adsorption-desorption isotherm according to the type of organic template, Table 5 shows the information on the specific surface area and the pore volume calculated from this nitrogen adsorption-desorption isotherm. Compared with the organic template-treated material, it is common to show that the nitrogen adsorption in the meso-cavity region increases rapidly when the organic material is reformed into organic material. Accompanying this means that the structure of the pupil is modified. In addition, it can be seen that the specific surface area and the pore volume increase in proportion to the molecular weight of the organic template used.

[Table 5] of SiO ₂ -Fe ₂ O ₃ Crosslinked Clay Synthesized Using Organic Template

Specific surface area and pore volume

Sample Surface area, ㎡ / g Pore volume, ml / g I.D. S _BET S _Lang. V _total SFM-Pristine 577 906 0.418 SFM-Q12 547 871 0.505 SFM-Q14 570 894 0.557 SFM-Q16 622 1005 0.615 SFM-Q18 624 1018 0.629 SFM-DS 658 1051 0.760 SFM-N18 411 653 0.684

Example 7

Porous crosslinked clay using Ni instead of Fe in Example 1 was prepared. Montmorillonite (Kunipia G, Kunimine Ind.) Was used as the starting material of clay, and NiCl ₂ ^. 6H ₂ O was used. The mixing amount of Ni made the molar ratio of Ni / Si / CEC (clay) 5/50/1. Processes other than this were performed in the same manner as in Example 1. However, when preparing a crosslinking sol-solution, the pH of the solution was adjusted to 4.3 to polymerize Ni ions. X- ray of the NiO-SiO ₂ crosslinked clay in the diffraction pattern of 2θ = 2 also NiO-SiO ₂ composite nanoparticles from the diffraction peak observed ^o very broad at the was able to confirm that the crosslinked interlayer, at 400 ^o C The specific surface area (S _BET ) of the heat-treated sample was 482 m ₂ / g to confirm that a material having excellent porosity was prepared. Elemental analysis through ICP (Table 6) confirmed that the content of NiO intercalated between the layers is 0.22 by molar ratio.

[Table 6] SiO ₂ -NiO using ICP Elemental Analysis of Crosslinked Clay

Sample Analytical results (mol%) Pillar composition a SiO ₂ NiO Al ₂ O ₃ (SiO ₂ ) _x (NiO) _y x + y SNM-400 ℃ 76.1 0.8 6.5 19.83 0.22 20.05

^{a The} composition of the crosslinking material is calculated by assuming the basic formula of montmorillonite. [(SiO ₂ ) _x (NiO) _y ] [(Si _3.89 Al _0.11 ) (Al _1.69 Mg _0.32 Fe _0.08 )] O ₁₀ (OH) ₂ .

Example 8

Porous crosslinked clay using Co instead of Fe in Example 1 was prepared. The starting material of clay is montmorillonite (Kunipia G, Kunimine Ind.), And the starting material of Co is CoCl ₂ ^. 6H ₂ O was used. The mixing amount of Co made the molar ratio of Co / Si / CEC (clay) 5/50/1. Processes other than this were performed in the same manner as in Example 1. However, when preparing a crosslinking sol-solution, the pH of the solution was adjusted to 4.3 to polymerize Ni ions. In the X-ray diffraction pattern of CoO-SiO ₂ crosslinked clays, the observation of very broad diffraction peaks near 2θ <2 ^o shows that the regularity of the crosslinked particle arrangements between layers is not high, but the starting clay inherent peak is not observed. It can be confirmed that the composite nanoparticles of CoO-SiO ₂ type were crosslinked between layers, and the specific surface area (S _BET ) of the sample heat-treated at 400 ^° C. was 540 m ² / g, and a material having excellent porosity was produced. It was confirmed. As a result of elemental analysis through ICP (Table 7), the content of CoO intercalated between layers was 0.21 in the case of NiO and lower molar ratio.

[Table 7] SiO ₂ -CoO using ICP Elemental Analysis of Crosslinked Clay

Sample Analytical results (mol%) Pillar composition a SiO ₂ CoO Al ₂ O ₃ (SiO ₂ ) _x (CoO) _y x + y SCM-400 ℃ 76.7 0.7 6.4 20.52 0.21 20.73

^{a The} composition of the crosslinking material is calculated by assuming the basic formula of montmorillonite. [(SiO ₂ ) _x (CoO) _y ] [(Si _3.89 Al _0.11 ) (Al _1.69 Mg _0.32 Fe _0.08 )] O ₁₀ (OH) ₂ .

Example 8

The SiO ₂ -Fe ₂ O ₃ crosslinked clay synthesized in Example 1 was heat treated in a reducing gas atmosphere to reduce Fe ₂ O ₃ particles intercalated into Fe metal. That is, the sample (SFM-Air-400) heat-treated under the air atmosphere at 400 ℃ for 2 hours was put into a tube-type electric furnace and heat-treated at 300 ~ 600 ℃ range for 2 hours while supplying hydrogen gas constantly. After the heat treatment, the color of the sample was changed from the initial reddish brown to silver gray, and it was also confirmed that Fe ₂ O ₃ was reduced to the metal Fe between layers. 6 is an X-ray diffraction diagram of a sample reduced at each temperature. From the figure, it can be seen that the lamination structure of the crosslinked nanoparticles is maintained even after reduction, and that the feature diffraction peaks due to the metal Fe are not clearly observed. And highly distributed. That is, it was confirmed that the Fe silica layer of silica silicate layer is fixed or supported by the SiO ₂ particles to prevent the aggregation of metal particles during the heat treatment process. Figure 7 compared the results of UV-Vis spectroscopy before and after the reduction treatment with hydrogen. In the pre-hydro treatment sample (SFM-Air-400), a unique absorption spectrum of Fe ₂ O ₃ nanoparticle size was observed over a wide frequency range, and the hydrogen reduction sample (SFM-H ₂ -400) was used for Fe metal particles. Characteristic absorption spectra by formation were observed. From this, it was confirmed that the Fe ₂ O ₃ particles present in the interlayer were reduced to Fe metal particles by hydrogen reduction treatment.

Example 9

Nitrogen adsorption-desorption isotherm analysis of the reduced SiO ₂ -Fe crosslinked clay (SFM-H ₂ -400) synthesized in Example 8 was carried out, and the specific surface area and pore volume calculated from this isotherm analysis are shown in Table 8. Indicated. It was confirmed that high specific surface area and pore volume were maintained even after reduction treatment with hydrogen.

TABLE 8 Reduced SiO ₂ -Fe Specific Surface Area and Porous Volume of Crosslinked Clay

Sample Surface area (㎡ / g) Pore volume (ml / g) S _BET V _total SFM-H ₂ -400 680 0.48

Example 10

Reduction was carried out in the same manner as in Example 9 except that nitrogen was used as a gas for reduction. Through the X-ray diffraction analysis after the reduction treatment, similar to Example 9, it was confirmed that the lamination and the porous structure were maintained from the observation of the unique diffraction pattern due to the lamination structure of the crosslinked material even after the reduction treatment. No diffraction pattern of the metal Fe due to aggregation of the particles was observed. From this, Fe metal particles also formed between the layers can be confirmed that the nanometer size and maintain a high dispersibility. From the nitrogen adsorption-desorption isotherm analysis, the specific surface area (S _BET ) was 687m ² / g and the pore volume was 0.49mL / g, and it was confirmed that high specific surface area and porous volume were maintained even when heat treatment was carried out using nitrogen as the reducing gas. .

Example 11

SiO ₂ -Fe ₂ O ₃ crosslinked clay (SFM-Air-400) which is a sample synthesized in Example 1 and SiO ₂ -Fe crosslinked clay (SFM-), which is a sample obtained by reducing the crosslinked clay in Example 8 Adsorption-desorption isotherms for toluene, one of the volatile organics for H ₂ -400), were measured using gravimetric analysis at room temperature and isotherms are shown in FIG. 8. As a result, the adsorption amount of toluene was 0.48 mL / g (SFM-Air-400) and 0.47 mL / g (SFM-H ₂ -400), respectively, and both types of porous crosslinking materials were adsorbed to volatile organic compound toluene. It was confirmed that the characteristics are very excellent.

Example 12

The adsorption rate of carbon monoxide (CO) of the SiO ₂ -Fe crosslinked clay (SFM-H ₂ -400), which was a sample synthesized in Example 8, was evaluated using an infrared spectroscopy. The evaluation was carried out by mounting 0.2 g of the sample in an IR cell with a total volume of 500 mL, vacuuming the cell, injecting 5,000 ppm of carbon monoxide therein, and measuring the permeability at a specific absorption peak of 2170 cm ^-1 over time. The removal rate was measured. 9 is a graph showing the removal rate of CO measured using infrared spectroscopy. From Figure 9 it can be confirmed that the porous crosslinked clay is very excellent adsorption removal rate of carbon monoxide.

Example 13

The ammonia removal rate of the SiO ₂ -Fe crosslinked clay (SFM-H ₂ -400) which is a sample synthesized in Example 8 was measured. The evaluation was performed by coating 0.2 g of the sample on a ceramic honeycomb carrier, mounting it in a reaction cell of 5.5 cm in diameter, and then measuring the concentration of ammonia that passed through the sample cell while constantly flowing ammonia at a concentration of 4 ppm. Was calculated. 10 is a graph showing the removal rate of ammonia over time, it was confirmed that the ammonia removal rate of 90% or more even up to 60 hours.

The metal-supported porous material provided through the present invention has a low manufacturing cost by using natural or synthetic clay as a carrier, and secondly, does not require expensive equipment in the manufacturing process and is simple in manufacturing process. Metals and metal oxides are stabilized in a highly dispersed state among the lattice layers of clay, so that the catalyst and adsorption performance are excellent, and the porosity of the particles is reduced and the structure is effectively modified by the aggregation of particles in the catalyst or adsorption process or regeneration process. Fourth, through easy control of process variables, pupil size, specific surface area, and porosity can be easily controlled.Fifth, it is possible to manufacture various types of materials such as sol, gel, and powder. It is possible to easily change the kinds of metals, supported metals and metal oxides, which shows the excellent application expandability of the material.

Therefore, the metal-supported porous material obtained through the present invention is ammonia and amine compounds, sulfur compounds, carbon monoxide, dioxin, volatile organic matter, nitrogen oxide, It has a feature that can be effectively applied to the purpose of adsorption removal and decomposition removal of sulfur oxides and the like.

Claims (13)

A method for producing a porous material and a method in which nanoparticles of a metal alone, a metal oxide alone, or a metal-metal oxide complex are crosslinked between layers of swellable clay. The metal of claim 1 is an alkali metal, alkaline earth metal, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Ga, Si, Mo, W, Nb, Sn, Sb, Ir, Ag, Cd , Ru, Pt, Rh, Pd, Au, characterized in that it comprises one or more selected from the lanthanum metal. The metal oxide of claim 1 is represented by M _x O _y and the metal ion (M) is at least one selected from Si, Zr, Ce, Fe, Cr, Mn, Nb, Ni, Cu, Co, and V = 1 ~ 3, y = 1 to 5 characterized in that it has an integer value. Swellable clay of claim 1 is characterized in that the synthetic or natural montmorillonite, hectorite, Weidelite, smectite-based clay including saponite, vermiculite, swellable mica, canneite, margotite, kenyanite To do. The metal, metal oxide, or metal-metal oxide composite nanoparticles of claim 1 are inserted into a single layer or multiple layers between layers of clay to form a crosslinked porous structure. The size of the nanoparticles of claim 1 is characterized in that 0.5 nm ~ 200 nm. Characterized in that the specific surface area of the porous material of claim 1 is 50 ~ 1000m ² / g. The method of claim 1 comprises the steps of dispersing the swellable clay in water or an organic solvent, preparing a crosslinking material, mixing and reacting the crosslinking material and the swellable clay, separating the reactant and the solvent, water or Washing with an organic solvent, drying, heating, and reducing the metal oxide to metal. The method of claim 8, wherein in the step of reacting the crosslinking material and the swellable clay, additionally, at least one organic material selected from a surfactant and a polymer material is added to the reaction. Reducing the metal oxide of claim 8 to the metal is characterized in that the treatment with a reducing gas selected from hydrogen, nitrogen, helium, carbon monoxide within a range of 1 hour to 24 hours in the range of 100 ~ 800 ^o C . The method of claim 8 characterized in that the product obtained in the sol or gel state obtained after the washing step is directly supported on a carrier, followed by heat treatment and reduction. The method of claim 11, wherein the carrier is selected from ceramic honeycomb, ceramic fiber, carbon fiber, ceramic foam filter, porous polymer, porous inorganic particles, nonwoven fabric. Claim 1 characterized in that the porous material has adsorption or decomposition properties for ammonia compounds, sulfur compounds, aldehydes, dioxins, volatile organics, carbon monoxide, nitrogen oxides, fluorine compounds, toxic gases, acidic gases, basic gases.

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