KR102498427B1 - Catalyst for Treating Hazardous Gas Generated in Semiconductor Manufacturing Process Using Metal Foam and Preparation Methods Thereof - Google Patents

Abstract

The present invention relates to a catalyst for removing harmful gases in a semiconductor manufacturing process and a method for manufacturing the same, and more particularly, has excellent thermal conductivity and thermal dissipation, and provides contact with the catalyst by securing various movement paths for harmful gases in a semiconductor manufacturing process. By using a metal foam structure in the form of a corrugate that can increase the area and prevent the occurrence of differential pressure between the upper and lower parts of the catalyst structure, and at the same time thinly coating the catalyst slurry containing the catalyst in a minimum amount on the inner and outer surfaces of the metal foam structure It relates to a catalyst for removing harmful gases in a semiconductor manufacturing process and a method for manufacturing the same, which can maximize the removal efficiency of harmful gases even in a harmful gas treatment process in a harsh environment due to excellent heat transfer and mass transfer even when a small amount of expensive active metal is used. .

Description

Catalyst for Treating Hazardous Gas Generated in Semiconductor Manufacturing Process Using Metal Foam and Preparation Methods Thereof}

The present invention relates to a catalyst for removing harmful gases in a semiconductor manufacturing process using metal foam and a method for manufacturing the same, and more particularly, to preventing damage to the catalyst due to catalyst poisoning or clogging of the catalyst in a process of removing harmful gases using a catalyst It relates to a catalyst for removing harmful gases in a semiconductor manufacturing process using metal foam, which enables stable continuous operation, and a manufacturing method thereof.

Semiconductor, which is also called the rice of industry, is the basis of recent industrial development, and the production of semiconductors is increasing every year along with the advancement of the industry. However, the semiconductor manufacturing process uses a wide variety of organic solvents and chemical gases due to the nature of the process. Many of these used materials are not consumed by the reaction and are discharged to the outside in the form of waste gases, and most of these waste gases are highly volatile. It is composed of components that are harmful to the human body or have a high global warming potential, and therefore, their removal is required.

Methods for removing the harmful waste gas developed so far include chemical cleaning, adsorption removal, direct combustion, catalytic combustion, and the like.

Chemical liquid cleaning uses an oxidizing agent to scrub harmful waste gas, and is suitable for low-concentration bulk gas treatment, but has the disadvantage of low deodorization efficiency and secondary pollutant emission. It is unsuitable for hazardous waste gas and has a disadvantage in that secondary contamination occurs when the used adsorbent is disposed of.

Direct combustion is a method of thermally oxidizing and decomposing harmful waste gases at a high temperature of 850 ℃ or higher. There is a disadvantage in that odor-causing substances or _NOx components generated as by-products due to operation at high temperatures may be discharged.

Catalyst The catalytic combustion method is advantageous for gas treatment with a medium concentration or less, and has the advantage of using a catalyst to oxidatively decompose harmful waste gases even at a lower operating temperature than direct combustion, but is weak against catalyst poisoning substances, and the components of harmful gases There is a disadvantage that the resolution may be lowered when there is a variety.

In order to compensate for such disadvantages, energy consumption has recently been minimized by using a thermal regenerative combustion method as a direct combustion method, and silane-based, halogen-based, There is a tendency to use a complex process in which sulfur compound-based and amine-based exhaust gases are oxidatively decomposed by catalyst combustion again.

In the catalytic combustion of the complex process, active metals in the form of oxides are supported on a ceramic carrier to prepare a catalyst, and the prepared catalyst is mixed with various additives such as a binder and coated on a monolith-type metal structure for use. . The metal structure in the form of a monolith is a method of converting harmful waste gases discharged from the rear end of the thermal storage combustion process into harmless substances by oxidizing and decomposing them.

However, the general monolithic catalyst structure as described above has a cell density of about 200 cpi to 1000 cpi and a channel length-to-diameter ratio (L/D) of about 70 to 120. A boundary layer is formed, which reduces heat and mass transfer, and it is difficult to uniformly coat the catalyst in the channel due to the capillary phenomenon, as well as frequent clogging and catalyst poisoning by unremoved harmful gases generated at the rear of the thermal storage combustion process. there was

Therefore, in the case of using a metal material as a catalyst structure in terms of heat and mass transfer, the catalyst or the ceramic support supporting the catalyst is separated from the metal structure at high temperature due to the physical bond between the metal structure and the ceramic support and the difference in thermal expansion coefficient, resulting in durability of the catalyst. And there was a problem that the activity is lowered.

In order to secure thermal shock stability and improve adhesion of the catalyst attached to the surface of the monolithic catalyst structure, Korean Patent Registration No. 0576737 coats the surface of the metal structure with first metal particles and heat-treats to form a first metal anti-corrosion protective layer, After coating the second metal particles on the surface of the protective layer and heat-treating to form a second metal catalyst carrier layer, as a final step, a catalyst is attached to the metal oxide layer by a wash coating method to obtain a monolithic catalyst module including a metal structure. manufactured.

However, as described above, when preparing a catalyst for removing harmful gases in a semiconductor manufacturing process using a metal structure, the prepared metal structure is subjected to heat treatment or surface treatment to have roughness, or modification on the surface of the metal structure It was prepared through a complicated process of repeating the steps of forming a pre-treated oxide layer and then additionally performing a heat treatment process to form a primer oxide layer.

Research and development has not yet been actively conducted on a method for maximizing production efficiency, such as the time required for these repeated various steps and additional cost issues.

Korean Patent Publication No. 2003-0025777 (published date: 2003.03.29) Korean Registered Patent No. 0654922 (Announcement date: 2006.12.06) Korean Patent Registration No. 0576737 (Announcement date: 2006.05.03)

The main object of the present invention is to solve the above-mentioned problems, and it is manufactured by a simplified manufacturing process without a pretreatment process, so that not only has excellent economic feasibility, but also has improved catalytic performance, a catalyst for removing harmful gases in a semiconductor manufacturing process using metal foam. It is to provide a manufacturing method of.

In addition, an object of the present invention is to treat unremoved harmful gases generated at the end of the thermal storage combustion process with high efficiency in treating harmful gases during the semiconductor manufacturing process, and to prevent blockage of the structure or damage to the catalyst due to poisoning. It is to provide a catalyst for removing harmful gases in a semiconductor manufacturing process using metal foam.

In order to achieve the above object, one embodiment of the present invention is (a) manufacturing a corrugated metal foam structure in which a flat plate of metal foam material and a corrugated plate of metal foam material are sequentially stacked; (b) a catalyst slurry containing an active material precursor, ceramic powder, a binder, and a solvent, including 20 to 70 parts by weight of an active material precursor, ceramic powder, and a binder based on 100 parts by weight of the solvent, and having a pH of 3.5 to 4.5; obtaining; and (c) coating the obtained catalyst slurry on the surface of the metal foam structure, drying and calcining to form a catalyst layer.

In a preferred embodiment of the present invention, the metal foam structure may be characterized in that it is selected from the group consisting of stainless steel, aluminum, iron, titanium and alloys thereof.

In a preferred embodiment of the present invention, the metal foam structure may have an average diameter of 400 μm to 5,000 μm and a porosity of 10 vol% to 55 vol%.

In a preferred embodiment of the present invention, the active material precursor may be characterized in that it includes one or more selected from the group consisting of platinum, palladium, rhodium and iridium.

In a preferred embodiment of the present invention, the ceramic powder may be at least one powder selected from the group consisting of alumina, titania, zirconia, mullite, cordierite and silica.

In a preferred embodiment of the present invention, the binder is an acrylate-based, polyvinyl alcohol-based, polyvinyl acetate-based, polyvinyl butral-based, polyvinylpyrrolidone-based, ethylcellulose-based, methylcellulose-based, nitrocellulose-based, At least one organic binder selected from the group consisting of carboxy methyl cellulose, hydroxy propyl methyl cellulose, methyl hydroxyethyl cellulose and epoxy; or at least one inorganic binder selected from the group consisting of silicate-based sol, alumina-based sol, titania-based sol, zirconia-based sol, ceramic wool, and bentonite.

In a preferred embodiment of the present invention, the catalyst layer may have a thickness of 5 μm to 60 μm.

In a preferred embodiment of the present invention, the catalyst slurry may include 0.1 to 20% by weight of the active material precursor, 55 to 90% by weight of the ceramic powder, and 5 to 30% by weight of the binder.

In a preferred embodiment of the present invention, the firing may be performed at 450 °C to 700 °C for 1 to 6 hours.

In a preferred embodiment of the present invention, the metal foam structure may be characterized in that it forms a polyhedron by stacking a plurality of layers.

In a preferred embodiment of the present invention, the interior angle (α) between the corrugated plate and one side of the plate may be characterized in that 40 ° ~ 80 °.

Another embodiment of the present invention is a corrugated metal foam structure in which a metal foam flat plate and a metal foam corrugated plate are sequentially stacked so as to penetrate harmful gases in a semiconductor manufacturing process in multiple directions; And a catalyst for removing harmful gases in a semiconductor manufacturing process comprising a catalyst layer containing an active material is provided by coating the catalyst slurry on the surface of the metal foam structure, drying and firing it.

The catalyst for removing harmful gases in the semiconductor manufacturing process according to the present invention has excellent thermal conductivity and thermal dissipation, increases the contact area with the catalyst by securing various movement paths for harmful gases in the semiconductor manufacturing process, and increases the differential pressure between the upper and lower parts of the catalyst structure. By using a metal foam structure in the form of a corgate that can prevent occurrence, and at the same time thinly coating the inner and outer surfaces of the metal foam structure with a minimal amount of catalyst slurry containing a catalyst, even though a small amount of expensive active metal is used, It has excellent heat transfer and mass transfer, so it can maximize the removal efficiency of harmful waste gas even in a hazardous waste gas treatment process in a harsh environment.

In addition, the method for manufacturing a catalyst for removing harmful gases in a semiconductor manufacturing process according to the present invention is an active metal precursor, ceramic powder, and binder included in the catalyst slurry through only one application of the catalyst slurry on a corrugated metal foam structure. Since it can be attached and coated on the metal foam structure without a pretreatment process, etc., excellent catalytic activity and durability can be exhibited without detaching of slurry particles containing a catalyst.

1 is a schematic manufacturing process diagram of a catalyst for treating harmful gases in a semiconductor manufacturing process using metal foam according to an embodiment of the present invention.
2 is a cross-sectional view of a metal foam structure according to an embodiment of the present invention.
3 is a cross-sectional view of a metal foam structure according to another embodiment of the present invention.

The catalyst for removing harmful gases in the semiconductor manufacturing process according to the present invention and the method for manufacturing the same are detailed below, but unless otherwise defined in the technical and scientific terms used at this time, those skilled in the art in the technical field to which this invention belongs Descriptions of well-known functions and configurations that have meanings commonly understood by the self and may unnecessarily obscure the subject matter of the present invention will be omitted in the following description.

Terms such as 'include', 'include' or 'has' described in this specification refer to the presence of features, values, steps, operations, components, parts, or combinations thereof described in the specification. It does not rule out the possibility that other features, figures, steps, operations, components, parts, or combinations thereof may exist or be added that have not been described.

In one aspect of the present invention, (a) manufacturing a corrugated metal foam structure in which a flat plate of metal foam material and a corrugated plate of metal foam material are sequentially stacked; (b) a catalyst slurry containing an active material precursor, ceramic powder, a binder, and a solvent, including 20 to 70 parts by weight of an active material precursor, ceramic powder, and a binder based on 100 parts by weight of the solvent, and having a pH of 3.5 to 4.5; obtaining; and (c) coating the obtained catalyst slurry on the surface of the metal foam structure, drying and calcining to form a catalyst layer.

In another aspect, the present invention includes a corrugated metal foam structure in which a metal foam flat plate and a metal foam corrugated plate are sequentially stacked so as to penetrate harmful gases in a semiconductor manufacturing process in multiple directions; And it relates to a catalyst for removing harmful gases in a semiconductor manufacturing process comprising a catalyst layer containing an active material by coating the catalyst slurry on the surface of the metal foam structure, drying and firing it.

The present invention relates to a catalyst for oxidatively decomposing harmful waste gases generated in a semiconductor manufacturing process, converting them into harmless substances, and removing them, and a method for manufacturing the same. It contains various volatile compounds such as chemical compounds and phosphorus compounds, and is sometimes treated using a high-temperature direct combustion method to convert them into harmless gases.

Recently, a thermal storage combustion method is used to reduce the energy required for the process by preparing a thermal storage body and storing the combustion heat in the thermal storage body to heat the introduced harmful gas. Secondary pollutants such as NO _x and hydrogen sulfide generated and odorous gas not removed and decomposition of silane generate fine silica powder particles and other fine particles. The undecomposed odor gas is removed again through a catalyst combustion process using a catalyst. At this time, fine particles such as silica powder cause fouling of the conventional monolithic catalyst structure and act as catalyst poisoning substances. .

Accordingly, the present invention provides a catalyst that does not significantly decrease in activity over time even in the presence of catalyst poisoning substances, and at the same time, provides a catalyst manufacturing method that maximizes production efficiency through a simplified catalyst manufacturing process without a pretreatment process.

Unlike the prior art, the present invention is a single process of directly coating a catalyst slurry containing an active material precursor, ceramic powder, and binder on the surface of a porous corgate-shaped metal foam structure that has not undergone a pretreatment process, followed by drying and firing It is to provide a catalyst for removing harmful gases in a semiconductor manufacturing process with excellent productivity and economy through simplification of the manufacturing process and a method for manufacturing the same.

In addition, a method of coating a catalyst slurry containing an active material precursor, ceramic powder, and a binder on the metal foam structure to apply the catalyst slurry to the inner and outer surfaces of the metal foam structure in a highly dispersed manner is also characterized.

Hereinafter, a preferred embodiment of a method for manufacturing a catalyst for removing harmful gases in a semiconductor manufacturing process according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic process diagram of a method for manufacturing a catalyst for removing harmful gases in a semiconductor manufacturing process according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a metal foam structure according to an embodiment of the present invention, and FIG. A cross-sectional view of a metal foam structure according to another embodiment of the invention.

1 to 3, the metal foam structure 10 according to the present invention is a corrugate-shaped metal foam structure, and uses a conventional powder catalyst and additives to perform multi-step processes such as kneading, injection, and molding. Compared to catalysts manufactured in the form of honeycomb, plate, etc. through a process, it can be manufactured through a simplified process, so production is easy, and installation or maintenance work is easy.

The metal foam structure is manufactured in a structure in which a plurality of metal foam flat plates 20 and metal foam corrugated plates 30 are sequentially stacked, and the flat plate 20 is formed in a flat shape of a metal foam material, and the corrugated plate ( 30) is formed in a corrugated or concave shape of a metal foam material. In this case, the flat plate and the corrugated plate of the metal foam structure may each have an average diameter of 400 μm to 5,000 μm and a porosity to area of 10 vol% to 55 vol%.

If the pore size and porosity of the flat and corrugated plates are out of the above ranges, clogging by fine silica powder particles and other fine particles may occur due to the characteristics of harmful gases in the semiconductor manufacturing process, or there may be problems with the flow of harmful gases. Since it can cause serious phenomena such as pressure drop as the occurrence occurs, it is necessary to have a certain or more pore size and porosity.

In addition, the pores of the flat plate and the corrugated plate are formed with pores of a smaller size along the flow direction of the harmful gas, so that the spatial utilization of the metal form can be maximized, and the pressure loss generated in the metal form can be minimized to remove harmful gases. efficiency can be improved.

The inner angle α between the corrugated plate and one surface of the flat plate formed by contacting the corrugated plate and the flat plate may be each independently 40 ° to 80 °, and preferably, the corrugated plate may be formed to be 40 ° to 60 °. If the interior angle (α) between the corrugated plate 30 and one surface of the flat plate 20 is less than 40 °, the cross-sectional area of the catalyst in contact with the toxic gas flow may increase, causing a problem that the back pressure increases, and exceeds 80 ° In this case, the cross-sectional area in contact with the flow of harmful gas becomes parallel, which may cause a problem in that the efficiency of removing harmful gas is lowered.

In the metal foam structure 10 according to the present invention, for example, a flat plate 20 is disposed between the corrugated plates, and the corrugated plates 34 and 44 and other corrugated plates stacked adjacent to the corrugated plates 34 and 44 Vertices A and B of (32 and 42) may be arranged to coincide with each other. Since the vertices of the corrugated plates are assembled to match each other in this way, the bearing capacity between the corrugated plates is improved to minimize deformation of the corrugated plates and flat plates due to external shock or vibration, pressure through which harmful gases pass, and thermal expansion due to temperature change. can

The number of corrugated plates and flat plates is not particularly limited and may vary greatly depending on the toxic gas treatment capacity, the thicknesses of the corrugated plates and flat plates may be independently different or the same, and there is an empty space between the plurality of corrugated plates and flat plates. It may be formed as a space (50). The cross-sectional area of the space 50 may also be the same or different independently, and the ratio of the open area not closed by the corrugated plate and flat plate to the total cross-sectional area of the metal foam structure is important when considering back pressure and harmful gas conversion efficiency.

The ratio of the open area (V) to the total cross-sectional area (A) of the metal foam structure can be expressed by Equation 1 below, and is 30% to 80%, preferably 40% to 70%, more preferably 40% It can be ~55%. The total cross-sectional area (A) may be the product of the height (H) and the width (W), and the open area (V) may be expressed by Equation 2.

[Equation 1]

Ratio (%) of open area (V) to total cross-sectional area (A) = V/A × 100

[Equation 2]

V = V1 + V2 + V3 + V4 + V5 + V6 + V7 + V8 + V9 + V10 … Vn

If the ratio of the open area (V) to the total cross-sectional area (A) of the metal foam structure is less than 30%, clogging by fine silica powder particles and other fine particles may occur due to the nature of harmful gases in the semiconductor manufacturing process, or harmful gases As problems occur in the flow, serious phenomena such as pressure drop may occur, and if it exceeds 80%, there is a problem in that the removal efficiency of harmful gases decreases. It should be possible to have an area ratio.

The corrugated plate and flat plate of the metal foam structure may be formed of various metals such as nickel, chromium, copper, stainless steel, aluminum, iron, titanium, etc. or their alloys, which have good heat transfer and heat dissipation, and the metal foam structure The manufacturing method can be produced by a conventional method used in the art.

The physical shape of the metal foam structure, such as length and high width, can be changed into various shapes such as circular and rectangular, and can be stacked in multiple layers to form a polyhedron.

The metal foam structure 10 is a corrugated structure in which a plurality of pores communicating with each other are formed so that harmful gases or gases penetrate in multiple directions, and the active catalyst is contained on the entire surface of the metal foam structure Catalyst slurry can be directly coated.

The catalyst slurry is composed of a mixture of an active material precursor, ceramic powder, a binder and a solvent in distilled water, and the active material precursor, ceramic powder and binder may be contained in an amount of 20 to 70 parts by weight based on 100 parts by weight of the solvent. .

If the active material precursor, ceramic powder, and binder are contained in an amount of less than 20 parts by weight based on 100 parts by weight of the solvent, the viscosity of the catalyst slurry is lowered so that the coating does not adhere to the metal foam structure and easily flows down during coating In addition, the content of the coated active catalyst is small, and the problem of lowering the efficiency of treating harmful gases may occur, and when the active material precursor, ceramic powder, and binder exceed 70 parts by weight based on 100 parts by weight of the solvent In this case, the catalyst slurry has a high viscosity, so a large amount of catalyst slurry is coated on the surface of the metal foam structure, resulting in a thick catalyst layer, and after drying and firing, the slurry is coated in a cracked form on the oxide catalyst surface, causing problems that it is easily broken. can

In the present invention, the active material precursor is composed of a main active material and an auxiliary active material, and any compound capable of removing harmful gases generated in the semiconductor manufacturing process can be used without limitation. For example, the main active material may be an oxide, chloride, nitride, hydrate, etc. including platinum, palladium, rhodium, iridium, etc., and the auxiliary active material may be an oxide, chloride, or nitride of tungsten, manganese, copper, or zinc. , hydrates, and the like.

The active material precursor may be included in an amount of 0.1% to 20% by weight based on the total weight of the active material precursor, ceramic powder, and binder, and the content of the active material precursor is less than 0.1% by weight based on the total weight of the catalyst slurry. In the case where the harmful gas treatment efficiency is lowered and exceeds 20% by weight, a problem in that manufacturing cost is increased compared to the harmful gas treatment effect may occur.

In addition, the ceramic powder serves as a carrier for supporting the active material precursor, and may be at least one powder selected from the group consisting of alumina, titania, zirconia, mullite, cordierite, and silica.

The ceramic powder may be included in an amount of 55% to 90% by weight based on the total weight of the active material precursor, the ceramic powder, and the binder. When the ceramic powder is included in an amount of less than 55% by weight, the slurry easily flows down on the metal foam structure due to the low viscosity of the catalyst slurry and is not coated, or even if a small amount is coated, several repetitions to coat a certain amount having catalytic activity A phosphorus process is required, and when it is contained in excess of 90% by weight, a large amount of catalyst slurry is coated on the surface of the metal foam structure, resulting in a thick catalyst layer, and after drying and firing, the slurry is coated in a cracked form on the surface of the oxide catalyst This can cause it to break easily.

Also, in the present invention, the average particle size of the ceramic powder may be 12 μm or less, preferably 0.01 μm to 5 μm. If the average particle size of the ceramic powder exceeds 12 μm, during coating of the catalyst slurry, it is not firmly adhered to the surface of the metal foam structure and easily flows down and is not coated, and even if some catalyst slurry is attached, it is easily affected by external impact after drying. Falling problems may occur.

Meanwhile, the binder serves to fix the above-described metal foam structure and ceramic powder to each other or to fix the ceramic powder to each other, and organic and/or inorganic binders may be used alone or in combination.

The organic binder is an acrylate-based, polyvinyl alcohol-based, polyvinyl acetate-based, polyvinyl butral-based, polyvinylpyrrolidone-based, ethyl cellulose-based, methyl cellulose-based, nitrocellulose-based, carboxy methyl cellulose-based, hydroxy propyl At least one selected from the group consisting of methyl cellulose, methyl hydroxy ethyl cellulose and epoxy may be used. Of these, it is preferable to use an acrylic modified epoxy.

In addition, as the inorganic binder, at least one selected from the group consisting of silicate-based sol, alumina-based sol, titania-based sol, zirconia-based sol, ceramic wool, and bentonite may be used. Among them, it is preferable to use silicaite-based sol.

The binder may be included in 5% to 30% by weight based on the total weight of the active material precursor, ceramic powder, and binder, and if the binder is included in less than 5% by weight based on the total weight of the catalyst slurry, the viscosity of the catalyst slurry And due to poor wettability, problems such as not being highly adhered to the surface of the metal foam structure and easily flowing down and not being coated may occur during coating. problems may arise.

The catalyst slurry according to the present invention may include additional additives such as a viscosity agent and a pH adjuster in addition to the above-mentioned components.

As the viscosity agent, at least one selected from the group consisting of polyethylene glycol, diethylene glycol, glycerol, ethylene glycol, dimethyl sulfoxide, formamide and N-methylformamide may be used. The viscosity agent may be included in an amount of 0.5 to 10% by weight based on the total weight% of the catalyst slurry.

As the pH adjusting agent, at least one selected from the group consisting of oxalic acid, citric acid, hydrochloric acid, nitric acid, sulfuric acid and phosphoric acid may be used. The pH adjuster may be included in an amount of 0.5 to 10% by weight based on the total weight of the catalyst slurry.

In addition, organic solvents such as methanol, ethanol, and acetone may be added and used as solvents added in addition to the distilled water.

The viscosity of the catalyst slurry according to the present invention can be adjusted according to the solid content, pH, and particle size of the pulverized solids. may be 200 cps to 500 cps, and in this case, the pH of the catalyst slurry may be 3.5 to 4.5.

In one embodiment of the present invention, a catalyst for removing harmful gases in a semiconductor manufacturing process can be prepared in a single process through coating the catalyst slurry on the metal foam structure, drying and heat treatment.

The coating method of the catalyst slurry can apply various methods such as applying, spraying, or supporting the catalyst slurry on the surface of the metal foam structure, and in terms of work efficiency, the catalyst slurry on each of the flat plate and corrugated plate of the metal foam structure After coating, it can be used by assembling into a structure.

The metal foam structure on which the catalyst slurry coating is completed is dried at room temperature ~ 50 ℃ for 1 hour to 3 hours at a heating rate of 0.1 ℃ / min ~ 1 ℃ / min, and then completely dried at 80 ℃ ~ 120 ℃ for 1 to 5 hours characterized by drying.

The metal foam structure after drying of the coated catalyst slurry may be calcined at 450 ° C to 700 ° C for 1 to 6 hours. At this time, the ceramic powder and active material components have specific crystals through a firing process, and the active material has a metal oxide form. By the firing process, the ceramic powder not only improves thermal stability and active metal dispersion by having a crystalline phase, but also serves to reduce poisoning of the catalyst included in the harmful gas. In addition, by converting the active material into a metal oxide form, it reacts with pollutants in harmful gases.

As described above, the catalyst slurry coated on the surface of the metal foam structure may form a thin catalyst layer having a thickness of 5 μm to 60 μm on the surface of the metal foam structure through drying and firing. If the thickness of the catalyst layer formed on the surface of the metal foam structure is less than 5 μm, it is difficult to form a uniform catalyst layer and the problem of reducing the efficiency of processing harmful gases may occur. If the thickness of the catalyst layer exceeds 60 μm, the thickness of the catalyst layer becomes thick Catalyst adhesion is reduced, and expensive active metals are used in large quantities, which may cause problems in that manufacturing costs increase.

Hereinafter, the present invention will be described in more detail by examples. These examples are only for explaining the present invention, it is apparent to those skilled in the art that the scope of the present invention is not limited to these examples.

<Example 1>

As an active material precursor, 0.8 g of hexachloroplatinic acid and 1.5 g of tungsten nitrate were mixed in 80 ml of distilled water (S), and 30 g of alumina (average particle size: 4 μm) powder and 6.9 g of silicaite-based sol were added thereto, respectively. Next, 3.5 g of oxalic acid was added to adjust the pH of the mixture to prepare a catalyst slurry (pH 4). Thereafter, the prepared catalyst slurry was wash-coated on the metal foam structure (α = 45 °, nickel-based) of FIG. 2 having an open area ratio of 50% to the total cross-sectional area. The catalyst structure coated with the catalyst slurry was dried at room temperature for 2 hours, and then calcined at 500° C. for 4 hours to prepare a catalyst having a catalyst layer thickness of 37 μm.

<Examples 2 and 3>

A catalyst was prepared in the same manner as in Example 1, but under the conditions shown in Table 1.

<Comparative Examples 1 to 4>

A catalyst was prepared in the same manner as in Example 1, but under the conditions shown in Table 1.

division catalyst slurry Catalyst layer thickness (㎛) metal foam structure menstruum
(parts by weight) Total content of active material precursor, ceramic powder and binder (parts by weight) Open Area Percentage (%) Example 1 100 49 37 50 Example 2 100 24 12 50 Example 3 100 65 58 50 Comparative Example 1 100 10 6 50 Comparative Example 2 100 85 84 50 Comparative Example 3 100 49 37 20 Comparative Example 4 100 49 37 90

<Experimental Example 1: Thermal shock measurement>

A thermal shock test was performed to compare the degree of peeling of the catalyst layer of the catalysts prepared in Examples and Comparative Examples. The catalysts prepared in Examples and Comparative Examples were heated with hot air at 500 ° C. for 1 minute and then cooled at room temperature for 30 seconds. The process was repeated 20 times to measure the weight change, and the results are shown in Table 2.

[Equation 3]

Coating Weight Loss Rate (%) = (W1-W2)/(W1-W) × 100

W: weight of metal foam structure before coating

W1: Weight of coated metal foam structure catalyst before test

W2: Weight of coated metal foam structure catalyst after test

division Coating weight weight loss rate (%) according to thermal shock test 10 thermal shock tests 15 thermal shock tests 20 thermal shock tests Example 1 0 0 0.2 Example 2 0 0 0.1 Example 3 0 0.2 0.3 Comparative Example 1 0 0.1 0.3 Comparative Example 2 5.7 8.1 10.9 Comparative Example 3 4.9 7.6 8.4 Comparative Example 4 0 0 0.1

As shown in Table 2, during the thermal shock test, the weight loss rate of the coating amount of Comparative Examples 2 and 3 continuously increased, while the weight loss of the coating amount in the case of the catalysts of Examples 1 to 3 and Comparative Examples 1 and 4 was There were few.

<Experimental Example 2: Evaluating Harmful Gas Removal Performance in Semiconductor Manufacturing Process>

In order to measure the activity of removing harmful wastes and odors of each catalyst, air mixed with 10 ppm of dichloromethane, 100 ppm of sulfur dioxide, 10 ppm of trimethylamine, and 10 ppm of ethylene was used as a standard test gas. The reaction conditions were carried out under the conditions of 400 ℃ and space velocity of 15,000 / hr, and the gas before and after the reaction was sampled and analyzed by TDU-GC-MS. Table 3 below shows the activity (conversion rate) according to the reaction time at 400 ° C for the standard sample gas of each Example and Comparative Example. Activity was calculated in terms of total hydrocarbons (THC).

division Conversion rate according to reaction time (%) 1 hour 15 hours 30 hours Example 1 94 91 89 Example 2 93 90 87 Example 3 93 91 89 Comparative Example 1 68 55 47 Comparative Example 2 88 69 40 Comparative Example 3 97 76 45 Comparative Example 4 71 64 49

As shown in Table 3, it was found that the catalysts of Examples 1 to 3 did not show significant decrease in activity over time as well as initial activity compared to the catalysts of Comparative Examples 1 to 4. In particular, in the case of the catalyst of Comparative Example 3, the initial activity was relatively high, but the activity decreased significantly with time, and in the case of Comparative Examples 2 and 3, it was confirmed that the catalyst layer was desorbed during the reaction process. Therefore, the catalyst according to the present invention exhibits high initial activity, high blood poisoning resistance, and high durability, so that it can be suitably used for treating harmful gases in a semiconductor manufacturing process.

<Experimental Example 3: Pressure loss and conversion rate performance evaluation according to cabinet>

The conversion rate after 1 hour was measured in the same manner as in Experimental Example 2, and the pressure loss of the catalyst structure was measured, and the results are shown in Table 4.

division Interior angle of metal foam structure (°) Conversion rate (%) Pressure loss (mmH ₂ O) Example 1 45 94 28 Comparative Example 5 25 90 53 Comparative Example 6 90 74 21

As shown in Table 4, it can be seen that Example 1 has excellent toxic gas removal efficiency while minimizing pressure loss compared to Comparative Examples 5 and 6, and the pressure loss and Conversion rates showed opposite trends. Comparative Example 6, in which the noxious gas flow and the cross sections of the corrugated plate and flat plate were arranged in parallel, had the lowest pressure loss and conversion rate, whereas the pressure loss and conversion rate were the highest in Comparative Example 5, in which the inner angle was arranged the smallest. I was able to confirm.

As above, specific parts of the present invention have been described in detail, but are not limited to those exemplified by examples, and for those skilled in the art, these specific descriptions are only preferred embodiments, and thereby the present invention It will be clear that the scope of is not limited. Accordingly, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

10: metal foam structure
20 : Reputation
32, 34, 42, 44: corrugated plate

Claims (12)

(a) manufacturing a metal foam structure having a corrugated shape in which a flat plate of metal foam material and a corrugated plate of metal foam material are sequentially stacked, and the ratio of the open area to the total cross-sectional area is 30% to 80%;
(b) a catalyst slurry containing an active material precursor, ceramic powder, a binder, and a solvent, including 20 to 70 parts by weight of an active material precursor, ceramic powder, and a binder based on 100 parts by weight of the solvent, and having a pH of 3.5 to 4.5; obtaining; and
(c) coating the obtained catalyst slurry on the surface of the metal foam structure, drying and firing to form a catalyst layer having a thickness of 5 μm to 60 μm A catalyst for removing harmful gases in a semiconductor manufacturing process, characterized in that it comprises the step of forming a catalyst layer Manufacturing method of.
According to claim 1,
The metal foam structure is a method for producing a catalyst for removing harmful gases in a semiconductor manufacturing process, characterized in that selected from the group consisting of nickel, stainless steel, aluminum, iron, titanium and alloys thereof.
According to claim 1,
The metal foam structure is a method for producing a catalyst for removing harmful gases in a semiconductor manufacturing process, characterized in that the average diameter of the pores is 400 ㎛ to 5,000 ㎛, and the porosity is 10 vol% to 55 vol%.
According to claim 1,
The active material precursor is a method for producing a catalyst for removing harmful gases in a semiconductor manufacturing process, characterized in that it comprises at least one selected from the group consisting of platinum, palladium, rhodium and iridium.
According to claim 1,
The method of manufacturing a catalyst for removing harmful gases in a semiconductor manufacturing process, characterized in that the ceramic powder is at least one powder selected from the group consisting of alumina, titania, zirconia, mullite, cordierite and silica.
According to claim 1,
The binder is acrylate-based, polyvinyl alcohol-based, polyvinyl acetate-based, polyvinyl butral-based, polyvinylpyrrolidone-based, ethyl cellulose-based, methyl cellulose-based, nitrocellulose-based, carboxy methyl cellulose-based, hydroxy propylmethyl At least one organic binder selected from the group consisting of cellulose-based, methylhydroxyethyl cellulose-based, and epoxy-based; or silicate-based sol, alumina-based sol, titania-based sol, zirconia-based sol, ceramic wool, and at least one inorganic binder selected from the group consisting of bentonite.
delete According to claim 1,
The catalyst slurry comprises 0.1 to 20% by weight of the active material precursor, 55 to 90% by weight of the ceramic powder, and 5 to 30% by weight of the binder, based on the total weight of the active material precursor, ceramic powder and binder Semiconductor manufacturing process, characterized in that A method for producing a catalyst for removing harmful gases.
According to claim 1,
The calcination is a method for producing a catalyst for removing harmful gases in a semiconductor manufacturing process, characterized in that carried out at 450 ℃ to 700 ℃ for 1 to 6 hours.
According to claim 1,
The method of manufacturing a catalyst for removing harmful gases in a semiconductor manufacturing process, characterized in that the metal foam structure is stacked in a plurality of layers to form a polyhedron.
According to claim 1,
Method for producing a catalyst for removing harmful gases in a semiconductor manufacturing process, characterized in that the interior angle (α) between the corrugated plate and one side of the flat plate is 40 ° to 80 °.
A corrugated metal foam structure in which a metal foam flat plate and a metal foam corrugated plate are sequentially stacked to penetrate harmful gases in a semiconductor manufacturing process in multiple directions; and
A catalyst for removing harmful gases in a semiconductor manufacturing process comprising a catalyst layer containing an active material by coating the catalyst slurry of claim 1 on the surface of the metal foam structure, drying and firing.

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