KR20240072939A - Porous hybrid catalysts and a manufacturing method thereof - Google Patents

Abstract

The present disclosure relates to a porous hybrid catalyst and a method for manufacturing the same, comprising: a core containing porous organic polymer particles; and a composite catalyst particle layer located on the surface of the core and comprising a porous support including mesopores and nanoparticles containing metal incorporated in the pores of the porous support. It's about.

Description

Porous hybrid catalysts and a manufacturing method thereof}

The present disclosure relates to a porous hybrid catalyst and a method for producing the same.

Transition metal nanoparticles can exhibit catalytic activity due to their high specific surface area, but since transition metal nanoparticles are primary particles and typically have an average particle size of 20 nm or less, the pore size is 2 nm to 50 nm to support these nanoparticles. ㎚ mesoporous support is considered preferable. The mesoporous support can be made of a metal oxide material, commonly known as silica, aluminosilicate, or titania. Depending on the manufacturing method, mesopores of various sizes and shapes can be formed, and the metal or quasi-skeleton forming the skeleton can be used as a mesoporous support. By adjusting the metal content, the concentration of acid sites and ion exchange ability can also be adjusted. Accordingly, mesoporous supports are being used as carriers for transition metal nanoparticles, and due to the characteristics of mesopores, the diffusion resistance of the material is lower than that of microporous supports, so it can have the advantage of a faster reaction rate.

However, the mesoporous support on which transition metal nanoparticles are supported is manufactured from powder particles, and when such powder particles are used as a catalyst, a pressure differential problem occurs as the catalytic reaction progresses.　Therefore, in order to alleviate the differential pressure problem and apply it to a commercial catalytic reaction process, catalyst powder particles must be supported on a substrate of a certain size or larger. In other words, even if a highly active catalyst is developed, it is essential to scale it up to suit the application environment in order to finally commercialize it.

As an example to solve this problem, a method of using a honeycomb monolith structure as a base for catalyst powder has been proposed. However, the honeycomb monolith structure has a very small specific surface area of 1.0 m2/g or less, so there is a problem in that the amount of catalyst that can be supported is small, and accordingly, there is a limitation in reducing the catalytic reaction efficiency. In addition, the inorganic substrate on which the catalyst powder is supported has a high specific gravity due to the nature of the material, making it difficult to apply to fields that require ductile materials. Furthermore, in environments where various mechanical external forces such as vibration or compression are applied, inorganic substrates have durability limitations such as detachment of catalyst powder, damage to the substrate, and subsequent decrease in catalytic activity.

Therefore, there is a need for the development of a new type of catalyst that can be used in a wide range of fields and can solve the above-mentioned problems.

: KR 10-2157740 B1 (2020.09.14)

One object of the present disclosure is to provide a porous hybrid catalyst that has excellent durability and constant catalytic activity even in environments where various mechanical external forces are applied.

Another object of the present disclosure is to provide a porous hybrid catalyst that has excellent catalytic activity and low specific gravity, which can be applied to products in various application fields.

Another object of the present disclosure is to provide a porous hybrid catalyst that has significantly excellent catalytic activity at room temperature and at the same time can significantly improve the differential pressure problem that occurs at high flow rates when using existing powder catalysts.

Another object of the present disclosure is to support catalyst particles not only on the outer surface of the core but also on the inner surface of the core by using organic polymer particles containing mesopores and/or macropores as the core. Accordingly, a porous hybrid catalyst with a significantly improved amount of catalyst particles supported per unit weight is provided. Furthermore, the aim is to provide a porous hybrid catalyst that can carry not only catalyst particles but also functional materials inside the core to realize not only a catalytic oxidation reaction but also additional effects according to the functional materials.

Another object of the present disclosure is to provide a porous hybrid that can substantially remove all harmful gases that are not removed only by the oxidation reaction due to contact between the harmful gas and the catalyst, even at a high flow rate, by organically combining the adsorption and desorption reaction and the catalytic oxidation reaction. It provides a catalyst.

A porous hybrid catalyst according to an aspect of the present disclosure includes a core including porous organic polymer particles; and a composite catalyst particle layer located on the surface of the core and including a porous support including mesopores and nanoparticles containing a metal incorporated into the pores of the porous support.

According to one embodiment, the porous organic polymer particles may include macro pores.

According to one embodiment, the glass transition temperature of the porous organic polymer particles may have a value of 300K or less.

According to one embodiment, the average pore size of the porous organic polymer particles may be larger than the particle size of the composite catalyst particles.

According to one embodiment, the porous support may be a metal oxide or metalloid oxide porous support.

According to one embodiment, the metal of the nanoparticles is gold (Au), silver (Ag), nickel (Ni), copper (Cu), cobalt (Co), palladium (Pd), platinum (Pt), and rhodium (Rh). ), ruthenium (Ru), iridium (Ir), molybdenum (Mo), and oxides thereof.

According to one embodiment, the metal of the nanoparticles may be gold (Au).

According to one embodiment, the nanoparticles may be incorporated into some of the mesopores of the porous support, and the mesopores not incorporated into the nanoparticles may be connected to each other through open pores.

According to one embodiment, the composite catalyst particles may be physically incorporated into the surface of the core.

According to one embodiment, the composite catalyst particles may be chemically bonded to the surface of the core.

According to one embodiment, the diameter distribution function obtained by Fourier transforming the extended X-ray absorption fine structure (EXAFS) spectrum of the composite catalyst particle may satisfy Equation 1 below.

[Equation 1]

(DH2/DH1) < 0.3

In the above equation 1, DH1 is the height of the peak at the interatomic distance D1, DH2 is the peak height at the interatomic distance D2, and D1 and D2 satisfy the following equations 2 and 3, respectively:

[Equation 2]

0.8≤(D1/D3)≤0.95

[Equation 3]

0.6≤(D2/D3)≤0.7

In Equation 2 and Equation 3, D3 refers to the interatomic distance of the Au-Au bond in the bulk phase that exists at 2.8 to 3.0 Å.

According to one embodiment, the composite catalyst particle may satisfy Equation 4 below.

[Equation 4]

(DA2/DA1) < 0.25

In Equation 4, DA1 is the area of the peak at the interatomic distance D1, DA2 is the area of the peak at the interatomic distance D2, and D1 and D2 satisfy Equation 2 and Equation 3 above, respectively.

According to one embodiment, the diameter distribution function may have a bimodal peak in the interatomic distance range of 2.2 Å to 3.0 Å.

According to one embodiment, the porous hybrid catalyst may be used for the oxidation reaction of carbon monoxide, aldehyde-based compounds, or hydrocarbon-based compounds.

An air purification filter according to an aspect according to the present disclosure includes a reaction filter unit having an internal space and a plurality of porous hybrid catalysts are filled in the internal space; an inlet provided on one side of the reaction filter unit through which gas containing harmful gases flows; and an outlet provided on the other side of the reaction filter unit through which gas from which harmful gases have been removed is discharged. The porous hybrid catalyst is characterized as being the porous hybrid catalyst as described above.

According to one embodiment, a particle filter unit for removing fine particles may be further included between the reaction filter unit and the inlet.

A method for producing a porous hybrid catalyst according to an aspect of the present disclosure includes (S1) preparing porous organic polymer particles; (S2) preparing a dispersion containing composite catalyst particles including a porous support including mesopores and nanoparticles containing metal incorporated in the pores of the porous support; (S3) applying the dispersion to the surface of the porous organic polymer particles; and (S4) drying the dispersion.

The porous hybrid catalyst according to the present disclosure can maintain excellent durability and constant catalytic activity even in environments where various mechanical external forces are applied.

The porous hybrid catalyst according to the present disclosure has excellent catalytic activity and low specific gravity, so it can be applied to products in various application fields.

The porous hybrid catalyst according to the present disclosure has significantly excellent catalytic activity at room temperature and at the same time can significantly improve the “differential pressure” problem that occurs at high flow rates when using existing powder catalysts.

The porous hybrid catalyst according to the present disclosure uses organic polymer particles containing mesopores and/or macropores as a core, so that catalyst particles can be supported not only on the outer surface of the core but also on the inner surface of the core. Accordingly, the amount of catalyst particles supported per unit weight can be significantly improved. Furthermore, by carrying not only catalyst particles but also functional materials inside the core, not only the catalytic oxidation reaction but also the effects of the functional materials can be implemented additionally.

The porous hybrid catalyst according to the present disclosure organically combines adsorption and desorption reactions and catalytic oxidation reactions, so that it is possible to substantially remove all harmful gases that are not removed only by the oxidation reaction due to contact between the harmful gases and the catalyst, even at high flow rates.

Figure 1 is a schematic diagram of a porous hybrid catalyst and composite catalyst particles included therein according to an embodiment.
Figure 2 is a schematic diagram of an air purification filter including the porous hybrid catalyst according to one embodiment.
Figure 3 shows a diameter distribution function obtained by Fourier transforming the EXAFS spectrum of composite catalyst particles according to one embodiment.

Unless otherwise defined, the technical and scientific terms used in this specification have meanings commonly understood by those skilled in the art to which this invention pertains, and the gist of the present disclosure is summarized in the following description and accompanying drawings. Descriptions of known functions and configurations that may unnecessarily obscure are omitted.

Additionally, as used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly dictates otherwise.

In addition, units used without special mention in this specification are based on weight, and as an example, the unit of % or ratio means weight % or weight ratio, and weight % refers to the amount of any one component of the entire composition unless otherwise defined. It refers to the weight percent occupied in the composition.

In addition, the numerical range used in this specification includes the lower limit and upper limit and all values within the range, increments logically derived from the shape and width of the defined range, all double-defined values, and the upper limit of the numerical range defined in different forms. and all possible combinations of the lower bounds. Unless otherwise specified in the specification of the present disclosure, values outside the numerical range that may occur due to experimental error or rounding of values are also included in the defined numerical range.

The term 'comprise' in this specification is an open description with the same meaning as expressions such as 'comprising', 'contains', 'has' or 'characterized by', and includes elements that are not additionally listed, Does not exclude materials or processes.

The term ‘surface’ in this specification refers not only to the outer surface of the core particle but also to the inner surface formed by pores inside the particle.

Hereinafter, the porous hybrid catalyst according to the present disclosure will be described in detail with reference to the attached drawings. The attached drawings are provided as examples in order to sufficiently convey the technical idea of the present disclosure to technicians, and the present disclosure is not limited to the drawings presented below and may be embodied in many other forms.

Figure 1 is a schematic diagram of a porous hybrid catalyst and composite catalyst particles included therein according to an embodiment.

Referring to FIG. 1, the porous hybrid catalyst 100 according to the present disclosure includes a core 110 including porous organic polymer particles; and a composite catalyst particle layer 120 located on the surface of the core and including a porous support 121 containing mesopores and nanoparticles 122 containing metal incorporated in the pores of the porous support. It is characterized by:

The porous hybrid catalyst has the above-described structure and has excellent catalytic activity due to the composite catalyst particles located on the surface of the core, and the composite catalyst particles are supported on the core surface, thereby forming a catalyst bed of the air purification device. By increasing the size of the filled particles, the pressure drop that occurs at high flow rates can be significantly reduced.

On the other hand, when using an inorganic material such as zeolite as the core, the pore size is only a few nanometers due to the nature of the inorganic material, so catalyst particles cannot be supported inside the core, so the amount of catalyst supported is small and the diffusion rate of reactants and products is low. There is.

On the other hand, the porous hybrid catalyst according to one embodiment includes porous organic polymer particles as a core, and thus has not only the outer surface of the organic polymer particle core containing mesopores and/or macropores, but also the inner surface of the core ( Catalyst particles can also be supported on the inner surface. Accordingly, the amount of catalyst particles supported per unit weight can be significantly improved, thereby increasing the catalytic reaction efficiency.

In the porous hybrid catalyst according to a preferred embodiment, the porous organic polymer particles may include macro pores, and the macro pores may have a structure of open pores connected to each other from the outer surface to the interior of the porous organic polymer particles. there is. Accordingly, the composite catalyst particles can be located not only on the outer surface of the porous organic polymer particles to form a coating layer, but also on the inner wall of the pores located inside the porous organic polymer particles to form a coating layer. Accordingly, the composite catalyst particles are uniformly distributed from the outer surface to the inner surface of the porous organic polymer particles, thereby inducing a catalytic reaction throughout the core of the porous organic polymer particles.

The porous hybrid catalyst according to one embodiment can further support not only catalyst particles but also functional materials as additives inside the core, so that not only the catalytic oxidation reaction but also the effects of the functional materials as additives can be additionally implemented. The additive may be an adsorbent, deodorant, or antibacterial agent.

In addition, by including porous organic polymer particles as the core, the specific gravity of the core can be significantly reduced compared to inorganic carriers such as zeolite, alumina, and silica, and can be applied to various fields that require a catalyst with a small specific gravity.

According to one embodiment, the porous hybrid catalyst includes porous organic polymer particles as a core, so that it can remove substantially all harmful gases contained in the air even at a high flow rate. In detail, harmful gases may be oxidized by contacting the surface of the composite catalyst particle layer or passing from the outside to the inside of the catalyst particle layer. However, only the contact between such harmful gases and the catalyst may not oxidize all of the harmful gases in the air. . A large amount of harmful gases that are not removed through the oxidation reaction through contact are quickly adsorbed inside the core through the pores of the porous organic polymer particles, and the harmful gases adsorbed inside the core are desorbed again and pass from the inside to the outside of the composite catalyst particle layer again. However, since it can be oxidized by catalyst particles, virtually all harmful gases can be removed even at high flow rates. Furthermore, as described above, the composite catalyst particles are located on the outer surface of the porous organic polymer particles and the inner walls of the pores located inside to form a coating layer, thereby inducing a catalytic reaction throughout the porous organic polymer particles. In addition, harmful gases adsorbed in the pores of the porous organic polymer can be easily oxidized by contact with catalyst particles while passing through the pores after being desorbed, which can be very advantageous in removing substantially all harmful gases. On the other hand, if the organic polymer particles are non-porous, the adsorption/desorption of the above-mentioned harmful gases may be limited, and they are bound to be oxidized only by contact with the surface of the composite catalyst particle layer, making it difficult for all harmful gases to be removed at a high flow rate. It can be difficult.

In addition, when applied to an air purification filter that needs to be filled with a certain volume, the conventional powder-type catalyst must be filled with more catalyst than necessary, whereas the porous hybrid catalyst can be filled with as much catalyst as necessary for air purification. Therefore, it has the advantage of being economically advantageous by reducing the amount of catalyst used.

The weight average molecular weight of the polymer constituting the porous organic polymer particles may be 10,000 g/mol or more, but may be, without limitation, 5,000,000 g/mol or less. For example, the weight average molecular weight of the polymer may be 10,000 to 5,000,000 g/mol or 20,000 to 1,000,000 g/mol, but is not limited thereto. The polymer may be a non-crosslinked polymer that is soluble in a solvent or a crosslinked polymer that is insoluble in a solvent, but is not limited to a specific structure.

The glass transition temperature of the porous organic polymer particles may range from 173K to 580K (Kelvin). According to one embodiment, the glass transition temperature may range from 273K to 580K, 298K to 580K, 343K to 580K, 373K to 580K, 423K to 580K, 473K to 580K, 423K to 573K, or 473K to 573K.

According to another embodiment, the glass transition temperature of the porous organic polymer particles may be in the range of 373K or less, 353K or less, 323K or less, specifically 300K or less, and may have a non-limiting range of 173K or more. More specifically, it may be 273K or less, 263K or less, 253K or less, 243K or less, or 220K or less, and may have a range of 173K or more. For example, the glass transition temperature may range from 173K to 300K, 173K to 273K, 173K to 263K, or 173K to 253K. When the glass transition temperature of the porous organic polymer particles is in the range of room temperature or lower, it has a rubbery state at room temperature. These rubber-like porous organic polymer particles can dissipate mechanical external force applied to the particles, thereby minimizing damage to the porous hybrid catalyst and detachment of catalyst powder, resulting in excellent durability. In particular, in the case of air purification devices operated at low temperatures below room temperature, porous hybrid catalysts provide a significant technical advantage in that the support can be damaged by mechanical external forces such as repetitive shock or vibration and the composite catalyst particles can easily be detached. You can.

According to one embodiment, the porous organic polymer particles may include mesopores and/or macropores, and specifically include pores with a size of 0.1 ㎛ to 1000 ㎛, 0.5 ㎛ to 500 ㎛, or 1 ㎛ to 100 ㎛. can do. Additionally, the porosity of the core may be 10 to 90%, specifically 20 to 80%. The porous organic polymer particles have large pores and porosity of the above-mentioned size, so that the composite catalyst particles can be uniformly supported inside the core and harmful gases can be removed more effectively.

According to one embodiment, the average pore size of the porous organic polymer particles may be larger than the particle size of the composite catalyst particles. Accordingly, through a simple dry or wet coating process, the composite catalyst particles can effectively penetrate into the interior of the porous organic polymer particles and be located on the inner wall of the pores, thereby easily forming a coating layer.

According to one embodiment, the diameter of the core is not particularly limited, but may be, for example, 100 ㎜ to 50 mm, specifically 0.5 mm to 50 mm, more specifically 1 mm to 25 mm, As the core satisfies the above-mentioned range, the differential pressure problem can be improved by increasing the size of the porous hybrid catalyst. At the same time, unlike conventional powder-type catalysts, there is no need to fill more catalyst than necessary and the amount of catalyst needed can be filled in the air purification filter, so it is economically advantageous by reducing the amount of catalyst usage.

According to one embodiment, the porous organic polymer particles may support not only the composite catalyst particles but also additives within the core. The additive may be any material required depending on the application field of the porous hybrid catalyst without limitation. For example, an adsorbent with excellent physical adsorption capacity such as activated carbon or an adsorbent with an antibacterial or deodorizing function such as copper sulfide (CuS). It can be a substance.

According to one embodiment, the organic polymer of the porous organic polymer particle may include any one or a combination of two or more selected from the group consisting of thermoplastic resin, thermosetting resin, elastomer, and thermoplastic elastomer. Non-limiting examples of the organic polymers include polyamide-based polymers, polycarbonate-based polymers, polyester-based polymers, fluorine-based polymers, polyurethane-based polymers, polystyrene-based polymers, polyolefin-based polymers, polyacrylate-based polymers, and polyvinyl chloride-based polymers. It may include any one or a combination of two or more selected from the group consisting of polymers, but is not limited thereto. The organic polymer of the porous organic polymer particle may be a hydrophobic polymer for effective adsorption of harmful gases and structural stability of the core, and may also be a water-insoluble polymer.

The specific material of the organic polymer may be appropriately selected depending on the technical field to which the porous hybrid catalyst is applied, but the material may be selected from the viewpoint of allowing the porous organic polymer particles to act as an adsorbent for reactive gas, for example, harmful gas. there is. For example, polystyrene-based polymer may be selected as a polymer material as an adsorbent for VOCs such as dichloroethane and trihalomethane. As organic polymer particles act as an adsorbent for harmful gases, as will be described later, the porous organic polymer particles can adsorb and physically remove harmful gases that cannot be completely removed by the composite catalyst particles at high flow rates, and the adsorbed harmful gases can be removed physically. During desorption, it may be desirable because it comes into contact with the composite catalyst particles and can be chemically removed.

According to a preferred embodiment, the organic polymer of the porous organic polymer particle may be an elastomer or thermoplastic elastomer, and can be more effectively used in fields where mechanical external force is applied than when an organic polymer with elasticity is used. Meanwhile, the organic polymer of the porous organic polymer particles may be a biodegradable polymer. As organic polymer particles are biodegradable, the burden on the environment is very small even if landfilled or disposed of due to a decrease in the catalytic activity of the porous hybrid catalyst, and the active metal can be easily recovered through a simple hydrolysis process after recovering the catalyst. It may be desirable.

According to one embodiment, the porous organic polymer particles may be foamed organic polymer particles, and the foamed organic polymer particles refer to organic polymer particles manufactured by a generally known foaming process. For example, the foamed organic polymer particles may be manufactured by melting and mixing an organic polymer and a foaming agent to produce a melt and foaming the melt by increasing the temperature or reducing the pressure. The foaming agent may be an organic foaming agent or an inorganic foaming agent. Examples of organic blowing agents include aliphatic hydrocarbons such as propane, butane, hexane or heptane, cycloaliphatic hydrocarbons such as cyclobutane or cyclopentane, and chlorofluoromethane. (chlorofluoromethane), trifluoromethane, 1,1-difluoroethane, 1,2,2,2-tetrafluoroethane (1,2,2,2-tetrafluoroethane) ), one or more selected from halogenated hydrocarbons such as methyl chloride, ethyl chloride, or methylene chloride. Examples of inorganic blowing agents include nitrogen, carbon dioxide, argon, or air.

According to another embodiment, the porous organic polymer particles may be manufactured by a manufacturing method known in the art, such as a solvent extraction process, a salt dissolution process, or a polymer dissolution process, and are limited to particles manufactured by a specific process. It doesn't work. For a specific example, the porous organic polymer particles are solidified into particles by adding and stirring a mixture of polymer, organic solvent, and non-solvent or oil into a cooled oil bath or aqueous solution, and then extracting the non-solvent or oil. It can be manufactured through a solvent extraction process. As another example, porous organic polymer particles can be manufactured through a salt dissolution process in which a mixture of a polymer, a solvent, and a water-soluble salt is added to an aqueous solution and stirred to solidify it into particles while simultaneously dissolving the salt. As another example, porous organic polymer particles can be manufactured through a polymer dissolution process in which a molten mixture of an organic polymer and a water-soluble polymer is put into a sedimentation tank and stirred to solidify into particles, and then the water-soluble polymer is removed by dissolving in the aqueous solution.

According to one embodiment, the porous support of the composite catalyst particles may be a metal oxide or metalloid oxide porous support. The metal or metalloid of the metal oxide or metalloid oxide may be from Groups 2 to 5, Group 7 to 9, and Group 11 to 14, and is specifically selected from Groups 2 to 4, Group 13, and Group 14. It may be a metal or metalloid, and more specifically, it may be Al, Ti, Zr, or Si.

The porous support includes mesopores and may optionally further include micropores. In the present disclosure, micropore means that the average diameter of internal pores is less than 2 ㎚, and mesopore (Mesopore) means that the average diameter of internal pores is 2 ㎚ to 50 ㎚. The volume of mesopores of the porous support may be 50 vol% or more, 60 vol% or more, or 70 vol% or more, and the upper limit is not limited, but for example, 100 vol% or less, 95 vol% or less, or 90 vol% or less. It may be 50 to 100% by volume, specifically 60 to 90% by volume, but this is only an example and is not limited thereto.

According to one non-limiting example, the porous support may have a hierarchical porous structure, and may include a structure in which micropores are regularly present between mesopores and are interconnected. However, since micropores are only an optional element, the porous support is not limited to a hierarchical porous structure.

According to a non-limiting example, the porous support may further include macro pores, and the inclusion of macro pores above a certain volume fraction may significantly reduce gas diffusion resistance, which may be preferable.

According to one embodiment, the metal of the metal-containing nanoparticles is gold (Au), silver (Ag), nickel (Ni), copper (Cu), cobalt (Co), palladium (Pd), platinum (Pt), and rhodium. It may be any one selected from the group consisting of (Rh), ruthenium (Ru), iridium (Ir), molybdenum (Mo), and oxides thereof. The metal-containing nanoparticles may be nanoparticles composed of metal. Specifically, the metal of the metal-containing nanoparticle may be gold (Au), and may be a gold nanoparticle.

The metal-containing nanoparticles can be prepared from methods known in the art or commercially available materials can be used. Specifically, metal-containing nanoparticles can be produced by reducing a metal precursor present in a solution to a metal according to a known method (Natan et al., Anal. Chem. 67, 735 (1995)). Examples of metal precursors include, but are not limited to, metal halides, metal nitrates, metal acetates, metal acetylacetonates, or metal ammonium salts. Specifically, the metal precursor is HAuCl ₄ , HAuBr ₄ , AgNO ₃ , [Ag(NH ₃ ) ₂ ]NO ₃ , CuCl ₂ , CuBr ₂ , PtCl ₂ , K ₂ PtCl ₄ , PdCl ₂ , NiCl ₂ , Ni(NO ₃ ) It may be any one selected from the group consisting of ₂ and combinations thereof, and more specifically, it may be HAuCl ₄ or HAuBr ₄ .

The diameter of the metal-containing nanoparticles may be 1 nm to 20 nm, specifically 1 nm to 15 nm, and more specifically 1 nm to 12 nm. The diameter of the metal-containing nanoparticles is preferably 1 nm to 10 nm, more preferably 1 nm to 8 nm.

According to one embodiment, the average diameter of the nanoparticles may be larger than the average diameter of mesopores of the porous support. Accordingly, it is possible to create a deformation of the crystal lattice of the metal-containing nanoparticles embedded in the mesopores of the porous support, and to improve catalytic activity in the room temperature range.

According to one embodiment, the nanoparticles may be incorporated into all of the mesopores of the porous support or into a portion of the mesopores of the porous support, and specifically, may be incorporated into a portion of the mesopores of the porous support. there is. More specifically, the nanoparticles may be irregularly incorporated into some of the mesopores of the porous support. At this time, the structure embedded in all of the mesopores of the porous support refers to a superlattice structure, and specifically refers to a highly ordered superlattice structure with face-centered cubic (FCC) symmetry. do. A form in which nanoparticles are irregularly incorporated into a portion of the mesopores is preferable in that it has the advantage of enabling gas diffusion more effectively compared to the superlattice structure.

According to one embodiment, the nanoparticles may be incorporated into some of the mesopores of the porous support, and the mesopores not incorporated into the nanoparticles may be connected to each other through open pores. In the porous hybrid catalyst, nanoparticles are incorporated into only a portion of the pores of the porous support, so that harmful gases can be more effectively diffused through pores that are not incorporated by nanoparticles connected to each other through open pores. Accordingly, the catalytic reaction rate of harmful gases within the composite catalyst particle layer can be increased.

According to one embodiment, the pores of the composite catalyst particle may be connected to the pores of the core through open pores. In the porous hybrid catalyst, the pores of the core and the pores of the composite catalyst particles are connected to each other, so that harmful gases can diffuse into the core and be quickly adsorbed in large quantities due to an increase in the material diffusion rate. As the adsorbed gas is desorbed, the composite catalyst particles Since it can be oxidized while passing from the inside to the outside again, virtually all harmful gases can be removed even at higher flow rates.

According to one embodiment, the composite catalyst particles may have an average particle diameter of 0.01 ㎛ to 10 ㎛, specifically 0.05 ㎛ to 5 ㎛, more specifically 0.1 ㎛ to 5 ㎛, and by satisfying the above range, the core phase Durability may be improved by binding more closely to the surface, but it is not limited to the above numerical range.

According to one embodiment, the composite catalyst particle has a specific surface area of 100 ㎡/g or more, 300 ㎡/g or more, 400 ㎡/g or more, 500 ㎡/g or more, 600 ㎡/g or more, 2,000 ㎡/g or less, or 1,500 ㎡/g or more. It may be ㎡/g or less, for example, 100 ㎡/g to 2,000 ㎡/g, 400 ㎡/g to 2,000 ㎡/g or 600 ㎡/g to 1,500 ㎡/g.

According to one embodiment, the composite catalyst particles may have a total pore volume of 0.08 cm3/g to 2.0 cm3/g, 0.08 cm3/g to 1.5 cm3/g, or 0.1 cm3/g to 1.0 cm3/g.

The composite catalyst particle satisfies the specific surface area, pore volume, and pore diameter within the above-mentioned ranges, allowing harmful gases to diffuse more effectively through pores. Accordingly, the catalytic reaction rate of harmful gases within the composite catalyst particle layer can be increased.

According to one embodiment, the composite catalyst particle includes a porous support including mesopores and nanoparticles containing a metal incorporated in the pores of the porous support, and uses an extended X-ray absorption fine structure (EXAFS) spectrum to perform Fourier analysis. The radial distribution function obtained by conversion can satisfy Equation 1 below.

[Equation 1]

(DH2/DH1) < 0.3

In equation 1, DH1 is the height of the peak at the interatomic distance D1, DH2 is the height of the peak at the interatomic distance D2, and D1 and D2 are expressed in the following equations 2 and 3, respectively. Satisfies. Specifically, D1 and D2 are the interatomic distances of the maximum peak found in a range that satisfies the following Equations 2 and 3, respectively.

[Equation 2]

0.8≤(D1/D3)≤0.95

[Equation 3]

0.6≤(D2/D3)≤0.7

In Equations 2 and 3 above, D3 refers to the interatomic distance of the Au-Au bond in the bulk phase that exists at 2.8 to 3.0 Å, and may specifically exist at 2.88 to 2.98 Å, and more specifically, the standard of 2.90 Å. It may mean the distance between atoms. Specifically, D3 refers to the interatomic distance of the Au-Au bond in the bulk at 2.8 to 3.0 Å, obtained through peak deconvolution when the peak appears as a single peak with asymmetry or has a bimodal peak. can do. The asymmetry means that although the peak has the shape of a single peak (unimodal peak), the left and right sides have asymmetry based on the center of the peak as two peaks overlap.

Specifically, (D1/D3) in Equation 2 may be 0.85 to 0.92, and (D2/D3) in Equation 3 may be 0.63 to 0.66.

According to a specific embodiment, in Equation 1, DH1 is the height of the peak at an interatomic distance of 2.57 ± 0.2 Å, and DH2 is the height of the peak at an interatomic distance of 1.85 ± 0.2 Å. You can. Specifically, DH1 may refer to the peak height of an interatomic distance of 2.57 ± 0.1 Å, and DH2 may refer to the peak height of an interatomic distance of 1.85 ± 0.1 Å.

As the composite catalyst satisfies the height ratio of the peak at the interatomic distance D1 to the peak at the interatomic distance D2 of less than 0.3, the catalytic activity can be significantly improved.

EXAFS stands for extended X-ray absorption fine structure, and can analyze the diameter distribution or coordination number of metal-containing nanoparticles. For example, when high-energy X-rays are irradiated to metal atoms, the metal atoms contained in the metal-containing nanoparticles emit electrons. Accordingly, radial scattered waves are generated centered on the metal atom that absorbed the X-rays, and when the electrons emitted from the metal atom that absorbed the Electrons are emitted. At this time, radial scattered waves are generated centered on other adjacent atoms.

The scattered waves generated around the metal atom that absorbed the X-rays and the scattered waves generated around other adjacent atoms (metal or oxygen atoms) interfere. At this time, a standing wave is obtained depending on the distance between the metal atom that absorbed the X-rays and another atom (metal or oxygen atom) adjacent to the metal atom. When the standing wave is Fourier transformed, a radius distribution having a peak depending on the distance between a metal atom and another atom (metal or oxygen atom) adjacent to the metal atom is obtained. For example, in the case of gold (Au) as a metal atom, not only the peak according to the distance between the gold (Au) atom but also the Au-O bond is observed when the gold (Au) atom has a bond with an oxygen atom. It is possible to obtain a diameter distribution with a peak depending on the distance between the gold (Au) atom and the oxygen atom.

According to one embodiment, (DH2/DH1) in Equation 1 may be 0.25 or less, more specifically 0.24 or less, 0.2 or less, 0.15 or less, 0.1 or less, or 0.05 or less, and may be non-limitingly 0 or more. By having the above numerical range, the catalytic activity of the composite catalyst particles is significantly improved, which is desirable in that substantially all of the reactant gas contained in the gas stream can be converted to product gas remarkably quickly.

According to one embodiment, the composite catalyst particle may have a radial distribution function obtained by Fourier transforming an extended X-ray absorption fine structure (EXAFS) spectrum that satisfies Equation 4 below.

[Equation 4]

(DA2/DA1) < 0.25

In Equation 4, DA1 is the area of the peak at the interatomic distance D1, DA2 is the area of the peak at the interatomic distance D2, and D1 and D2 satisfy Equation 2 and Equation 3 above, respectively.

According to a specific embodiment, in Equation 4, DA1 is the area of the peak with an interatomic distance of 2.57 ± 0.2 Å, and DA2 means the area of the peak with an interatomic distance of 1.85 ± 0.2 Å. You can. Specifically, DA1 may refer to the area of the peak with an interatomic distance of 2.57 ± 0.1 Å, and DA2 may refer to the area of the peak with an interatomic distance of 1.85 ± 0.1 Å.

As the composite catalyst particle satisfies the area ratio between the peak at the interatomic distance D1 and the interatomic distance D2 of less than 0.25, the catalytic activity can be significantly improved.

According to one embodiment, (DA2/DA1) in Equation 2 may be 0.2 or less, specifically 0.18 or less or 0.15 or less, more specifically 0.1 or less or 0.05 or less, and is not limited to 0 or more. You can. By having the above numerical range, the catalytic activity of the composite catalyst particles is significantly improved, which is desirable in that substantially all of the reactant gas contained in the gas stream can be converted to product gas remarkably quickly.

The numerical ranges of Equations 1 and 4 obtained from the EXAFS (Extended Although it can be implemented through examples, the numerical ranges of Equations 1 and 4 above are not limited to one embodiment.

According to one embodiment, the diameter distribution function obtained by Fourier transforming the extended X-ray absorption fine structure (EXAFS) spectrum may have a bimodal peak in the interatomic distance range of 2.2 to 3.0 Å. For a specific example, the interatomic distance range of 2.2 to 3.0 Å may be a section where the distance between gold (Au) atoms is located, and refers to the distribution of the interatomic distance of Au-Au in the crystal lattice. do.

In the range of 2.2 to 3.0 Å between atoms, typical metal-containing nanoparticles can exhibit a single peak, and having a single peak means that the distance between metal-metal atoms is constant within the crystal lattice of the nanoparticle. do. However, having a bimodal peak may mean that different metal-metal interatomic distances exist within the crystal lattice, and although it has not been clearly identified, two different metals may be formed due to deformation of the crystal lattice due to compressive stress. -It is inferred that distance between metal atoms is created. As it has a positive peak in the interatomic distance range of 2.2 to 3.0 Å, it can exhibit very excellent catalytic activity even in low temperature regions, and can convert substantially all of the reactant gas contained in the gas stream at high flow rate into product gas very quickly. It is desirable in that it can be done.

According to one embodiment, the composite catalyst particle may be included in an amount of 50 to 1000 parts by weight, specifically 100 to 500 parts by weight, based on 100 parts by weight of the core containing the porous organic polymer particles, but is not limited thereto. Compared to inorganic carriers such as zeolite, alumina, and silica, the specific gravity of the core can be significantly reduced, so it can be applied to various fields that require a catalyst with a small specific gravity. In addition, the amount of catalyst particles supported per unit weight is significantly improved, making it possible to significantly reduce the specific gravity of the core. Reaction efficiency can be increased. In addition, the specific gravity of porous organic polymer particles is very low, so the amount of catalyst particles supported per unit weight or unit volume of the porous hybrid catalyst can be significantly improved compared to the inorganic support core, thereby increasing catalytic reaction efficiency.

Additionally, as the composite catalyst particles satisfy the content within the above-mentioned range, they can be coated on the surface of the core to uniformly form a surface coating layer.

According to one embodiment, the composite catalyst particles may be physically incorporated into the surface of the core. Since the organic polymer contained in the core has viscoelasticity and has a lower specific gravity than the composite catalyst particle, the composite catalyst particle can be easily physically incorporated into the surface of the core. As a portion of the total volume of the composite catalyst particles is absorbed into the surface of the core, the composite catalyst particles can be strongly bound. The volume of composite catalyst particles incorporated into the surface of the core may be, for example, less than 50%, less than 40%, less than 30%, less than 20%, less than 10% or less than 5%, and may also be more than 0.1%. The composite catalyst particles can be bound to the core without the need for an additional binder, detachment of the composite catalyst particles can be effectively suppressed, and the porous hybrid catalyst can have excellent durability.

The composite catalyst particles can be easily physically incorporated into the core surface by heat treatment under mild conditions after being coated on the core surface by applying powder or dispersion. The heat treatment conditions may be a temperature above the Vicat softening point and below the melting point of the organic polymer contained in the porous organic polymer particles. The Vicat softening point can be specified by ASTM D 1525.

According to another embodiment, the composite catalyst particles may be chemically bonded to the surface of the core. The surface of the core may include a functional group capable of binding to the composite catalyst particle, and the composite catalyst particle may be bound to the core surface as the functional group present on the surface of the core and the composite catalyst particle chemically bond to each other. there is. The functional group may be included chemically bonded to the organic polymer included in the core, or may be included physically mixed with the organic polymer with a coupling agent. For example, a physically mixed coupling agent is R ₁ -SiR ₂ R ₃ R ₄ (R ₁ is alkyl of C6-C20, R ₂ is halogen, hydroxy or alkoxy of C1-C4, R ₃ and R ₄ are Independently of each other, it may have a structure of C1-C4 alkyl, halogen, hydroxy, or C1-C4 alkoxy). The coupling agent is physically mixed with the organic polymer and is uniformly positioned on the surface of the porous organic polymer particles, and the hydroxyl group or alkoxy group of the coupling agent undergoes a condensation reaction with the composite catalyst particles to bind the composite catalyst particles to the core surface. You can.

According to one embodiment, the composite catalyst particles may exist forming a single layer on the surface of the core. By dry or wet coating the composite catalyst particles on the core, single particles may be physically embedded or chemically bonded to the surface of the core. The composite catalyst particles may have a stacked structure due to van der Waals forces, but forming a single layer on the surface of the core by physical impregnation or chemical bonding rather than existing in a stacked structure makes the composite catalyst particles more stable. It is desirable in that it can be supported. For example, the composite catalyst particles present in a single layer may be at least 40% by mass, at least 50% by mass, at least 60% by mass, at least 70% by mass, at least 80% by mass, or at least 90% by mass, relative to the total mass of the composite catalyst particles. and may be 100% by mass or less, but is not limited thereto.

According to one embodiment, the average thickness of the composite catalyst particle layer is not particularly limited thereto, but may be, for example, 1 ㎛ to 50 ㎛, specifically 2 ㎛ to 40 ㎛, 2 ㎛ to 30 ㎛, 2 ㎛ It may be ㎛ to 20 ㎛ or 2 ㎛ to 10 ㎛.

According to one embodiment, the porous hybrid catalyst may be used for the oxidation reaction of carbon monoxide, aldehyde-based compounds, or hydrocarbon-based compounds. Accordingly, the porous hybrid catalyst according to the present disclosure can be preferably used as a solid-phase oxidizing agent for carbon monoxide, aldehyde-based compounds, or hydrocarbon-based compounds. The aldehyde-based compound may be acetaldehyde or formaldehyde, but is not limited thereto. The hydrocarbon-based compound may be an aliphatic or aromatic compound or a volatile organic compound (VOC), and examples include, but are not limited to, methane, ethane, propane, butane, benzene, toluene, or xylene.

According to one embodiment, the porous hybrid catalyst converts a 4% concentration carbon monoxide-containing gas into carbon dioxide with a conversion efficiency of 80% or more, specifically 85% or more, and more specifically 90% or more at room temperature under a flow rate condition of 100 ml/min. can do. In addition, it can be converted to carbon dioxide with a conversion efficiency of 80% or more, specifically 85% or more, and more specifically 90% or more at room temperature under a flow rate condition of 140 mL/min. Carbon monoxide-containing gas may contain a certain amount of oxygen in order to be oxidized, for example, 2% or more, 4% or more, 10% or more, and without limitation, 30% or less. For example, the gas containing carbon monoxide may be air, but is not limited thereto as long as it is a gas containing oxygen above a certain content.

Figure 2 is a schematic diagram of an air purification filter including the porous hybrid catalyst according to one embodiment.

The air purification filter according to the present disclosure includes a reaction filter unit 200 having an internal space and a plurality of porous hybrid catalysts are filled in the internal space; an inlet 300 provided on one side of the reaction filter unit through which gas 10 containing harmful gases flows; and an outlet 400 provided on the other side of the reaction filter unit through which the gas 20 from which harmful gases have been removed is discharged. The porous hybrid catalyst is characterized in that it is the porous hybrid catalyst 100 described above.

According to one embodiment, the harmful gas may be one or a combination of two or more selected from the group consisting of carbon monoxide, aldehyde-based compounds, and hydrocarbon-based compounds. The aldehyde-based compound may be acetaldehyde or formaldehyde, but is not limited thereto. The hydrocarbon-based compound may be an aliphatic or aromatic compound, and examples include methane, ethane, propane, butane, benzene, toluene, or xylene, but are not limited thereto.

Referring to Figures 1 and 2, in addition to contact with the porous hybrid catalyst 100 filled in the reaction filter unit 200, the harmful gas introduced through the inlet 300 also undergoes adsorption and desorption reactions and catalytic oxidation reactions. Even at the flow rate, substantially all of it can be removed and discharged through the outlet 400.

More specifically, a large amount of harmful gases that are not removed through the oxidation reaction through contact are rapidly adsorbed inside the core through the pores of the porous organic polymer particles, and the harmful gases adsorbed inside the core are desorbed again from the inside to the outside of the composite catalyst particles. It can be oxidized as it passes again in this direction, allowing virtually all harmful gases to be removed even at high flow rates.

In addition, the air purification filter according to one embodiment includes a porous hybrid catalyst using the above-described porous organic polymer particles as a core, and thus, catalytic reaction occurs due to an increase in the amount of catalyst supported compared to the case of using an inorganic support such as zeolite, alumina, and silica. Efficiency can be improved and additional effects depending on functional materials can be realized. In addition, the air purification filter has high durability and can maintain continuous catalytic activity because the composite catalyst particles easily adhere to the surface and interior of the porous organic polymer particles and do not desorb.

In addition, as the particle size of the porous hybrid catalyst 100 filled in the reaction filter unit 200 increases and the volume of pores between particles increases, the differential pressure that occurs at a high flow rate when using a conventional powder catalyst This can significantly alleviate the problem. Moreover, when applied to an air purification filter that needs to be filled with a certain volume, the conventional powder-type catalyst must be filled with more catalyst than necessary, whereas the porous hybrid catalyst can be filled with as much catalyst as necessary for air purification. Therefore, it has the advantage of being economically advantageous by reducing the amount of catalyst used.

Although not shown in FIG. 2, the air purification filter may further include a particle filter unit for removing fine particles between the reaction filter unit 200 and the inlet 300. As a result, the air purification filter can remove some of the harmful gases contained in the gas before passing through the reaction filter unit 200, and thus can completely remove the harmful gases contained in the gas even at a higher flow rate.

The method for producing a porous hybrid catalyst according to the present disclosure includes the steps of (S1) preparing porous organic polymer particles; (S2) preparing a dispersion containing composite catalyst particles including a porous support including mesopores and nanoparticles containing metal incorporated in the pores of the porous support; (S3) applying the dispersion to the surface of the porous organic polymer particles; and (S4) drying the dispersion; It is characterized by including.

In the method for producing the porous hybrid catalyst, the order of steps S1 and S2 is not limited, and the above-described methods can be applied to the porous organic polymer particles, porous supports, and nanoparticles.

The porous hybrid catalyst manufactured by the above-described manufacturing method essentially uses a binder for binding to the catalyst particles in the case of a porous inorganic support, whereas the use of porous organic polymer particles allows the composite catalyst particles to be formed on the surface of the core and the surface of the core without a binder. It can be stored inside. However, the present disclosure does not exclude an embodiment in which a binder is included.

For example, in step S2, the dispersion may further include a binder, and the binder may include an inorganic binder, an organic binder, or a combination thereof. Specifically, an inorganic binder and an organic binder may be used interchangeably. there is. More preferably, the binder may include an inorganic sol binder and/or a water-soluble polymer binder, and the inorganic sol binder may be, for example, silica sol, but is not limited thereto, and the average particle diameter of the inorganic sol binder is 1 to 1. It may be 50 nm and may be included at 0.5 to 3% by weight in the dispersion. The water-soluble polymer binder may be any one or two or more selected from the group consisting of polyethylene glycol, polyvinyl alcohol, and poly(N-vinyl pyrrolidone). The water-soluble polymer binder may be included in an amount of 1 to 5% by weight in the dispersion. The weight average molecular weight of the water-soluble polymer binder may be 10,000 to 1,000,000 g/mol, but is not limited thereto. Specifically, the binder may be a combination of silica sol and polyvinyl alcohol, and through the combination, the composite catalyst particles can be firmly bound to the inorganic particles to exhibit excellent durability.

The dispersion may have a slightly acidic pH of 2 to 6 or pH 3 to 5. The solvent of the dispersion is not particularly limited, but may be, for example, water, alcohol, or a combination thereof.

According to one embodiment, in step S2, the dispersion may further include an additive, and the above-described provisions may apply to the additive. The porous hybrid catalyst further includes an additive that can act as a functional material, so that not only catalyst particles but also functional materials can be supported inside the core, so that not only the catalytic oxidation reaction but also the effects of the functional material can be additionally implemented.

In step S3, the dispersion may be applied to the surface of the porous organic polymer particles using a coating method known in the art, such as spray-coating or dip-coating.

According to one embodiment, a heat treatment step under mild conditions may be added after step S3 or step S4 to physically incorporate the composite catalyst particles into the surface of the porous organic polymer core. The heat treatment conditions may be a temperature above the Vicat softening point and below the melting point of the organic polymer contained in the porous organic polymer particles. The Vicat softening point can be specified by ASTM D 1525.

Hereinafter, examples and experimental examples will be described in detail below. However, the examples and experimental examples described below are only illustrative of some, and the technology described in this specification is not limited thereto.

<Preparation Example 1> Preparation of composite catalyst particles 1

[Step 1]: Preparation of gold nanoparticles functionalized with polymer

[Step 1-1]: Gold nanoparticles stabilized with oleylamine are synthesized according to the following procedure.

First, olein amine was selected as a stabilizer, and a solution consisting of 60 ml of toluene, 60 ml of oleylamine, and 0.6 g of HAuCl·3H ₂ O was prepared by stirring at room temperature for 10 minutes. 6 mmol of Tetrabutylamine borane complex, 6 mL of toluene, and 6 mL of oleylamine were mixed by ultrasonic pulverization and quickly added to the solution. Then, the solution was stirred at room temperature for another hour, ethanol was added, and then centrifuged to precipitate gold nanoparticles. The gold nanoparticle precipitate was redispersed with toluene, ethanol was added, and centrifuged. The produced gold nanoparticles had an average particle diameter of 4 nm, and the produced gold nanoparticles were dispersed as-formed in 100 ml of toluene.

[Step 1-2]: The surface of the gold nanoparticle is functionalized with thiolated PEG using the following method.

In step 1-1, the gold nanoparticles dispersed in toluene were diluted by adding an additional 100 ml of tetrahydrofuran, and a thiolated polymer was selected to functionalize the gold nanoparticles by binding the polymer to the surface, and 1 g of Monofunctional polyethylene glycol (aSH-PEG, weight average molecular weight: 1 kDa) whose terminal was substituted with a thiol group was added. After stirring, hexane was added and centrifuged to precipitate PEG-functionalized gold nanoparticles (Au-PEG). Au-PEG obtained by precipitation was dried and then dispersed in water.

[Step 2]: Preparation of porous silica containing PEG-functionalized gold nanoparticles

0.088 g of Au-PEG prepared in step 1-2 was mixed with 0.396 g of Pluronic F127 as an activator and uniformly dispersed in 10 ml of 1.6 M HCl aqueous solution, and then 1.49 g of tetraethylorthosilicate ( TEOS) was applied. Then, the dispersion of the mixture was stirred for 15 minutes and maintained without stirring at room temperature for 40 hours to prepare a red precipitate. The red precipitate corresponds to porous silica containing PEG-functionalized gold nanoparticles.

[Step 3]: Preparation of composite catalyst particles

The red precipitate prepared in the previous step was washed with water, dried, and then calcined in stages for 3 hours at 250°C, 2 hours at 400°C, and 2 hours at 500°C to remove PEG and Pluronic F127 polymers, thereby producing gold nanoparticles. Entrapped porous silica composite catalyst particles 1 were prepared.

<Preparation Example 2> Preparation of composite catalyst particles 2

The same steps were performed except that gold nanoparticles with an average particle diameter of 10 nm were prepared by adjusting the molar ratio of oleinamine and HAuCl·H ₂ O in step 1-1 of Preparation Example 1, thereby producing gold nanoparticles. A composite catalyst particle 2 containing porous silica was prepared.

<Preparation Example 3> Preparation of composite catalyst particles 3

The same steps 1 and 2 were performed except that gold nanoparticles with an average particle diameter of 12 nm were prepared by adjusting the molar ratio of oleinamine and HauCl·H ₂ O in step 1-1 of Preparation Example 1. In Step 3, the red precipitate prepared in the previous step was washed with water, dried, and then calcined at 450°C to remove PEG and Pluronic F127 polymer, thereby preparing porous silica composite catalyst particles 3 containing gold nanoparticles.

<Preparation Example 4> Preparation of composite catalyst particles 4

In step 2 of Preparation Example 1, the same steps were performed except that 0.396 g of Pluronic F127 was not used, thereby preparing porous silica composite catalyst particles 4 in which gold nanoparticles were captured in a superlattice structure.

<Preparation Example 5> Preparation of composite catalyst particles 5

Composite catalyst particles 5 were prepared by performing all other steps in the same manner, except that step 2 of Preparation Example 1 was performed as follows.

Specifically, in Step 2, to prepare porous alumina with gold nanoparticles trapped, 0.15 g of PEG-functionalized gold nanoparticles (Au-PEG) and Pluronic were added to a mixed solution of 0.8 ml of nitric acid (68%) and 40 ml of ethanol. A uniform dispersion was prepared by mixing 0.675 g of F127. 2.15 g of aluminum ethoxide was added to the dispersion. The dispersion of the mixture was stirred for 3 hours, maintained at room temperature for 24 hours without stirring, and then dried at 60°C for 3 hours to prepare a red solid.

<Preparation Example 6> Preparation of composite catalyst particles 6

Composite catalyst particles 6 were prepared by performing all other steps in the same manner, except that step 2 of Preparation Example 1 was performed as follows.

Specifically, in Step 2, to prepare porous titania with gold nanoparticles trapped, 0.15 g of PEG-functionalized gold nanoparticles (4-Au-PEG) were added to a mixed solution of 0.68 ml of 37% hydrochloric acid and 17.05 ml of ethanol. A uniform dispersion was prepared by mixing 0.56 g of Pluronic F127. A mixed dispersion was prepared by adding 2.28 g of titanium tetraisopropoxide to the dispersion. Then, the mixed dispersion was stirred for 3 hours, stirred at room temperature for 24 hours, and then dried at 60°C for 3 hours to prepare a dark red solid.

(Preparation Example 7) Preparation of composite catalyst particles 7

A TEOS solution was prepared by dissolving 10 g of tetraethyl orthosilicate (TEOS) in 12.0 g of ethanol, adding 5.4 g of 0.01 M hydrochloric acid, and stirring for 20 minutes at room temperature. After dissolving 2.8 g of Pluronic F127 in 6 g of ethanol, the solution was added to the TEOS solution, stirred at room temperature for 3 hours, and maintained at room temperature for 40 hours without stirring to prepare a precipitate. The precipitate was washed with water, dried, and calcined at 500°C for 7 hours to prepare mesoporous silica.

The mesoporous silica powder was immersed in HAuCl ₄ ·3H ₂ O aqueous solution, and the excess aqueous solution was removed through air blowing. After drying at 300°C for 3 hours, porous silica composite catalyst particles 7 containing gold nanoparticles were prepared by firing at 250°C for 1 hour in a reduction gas containing 10% hydrogen gas and 90% nitrogen gas.

<Preparation Example 8> Preparation of porous organic polymer particles 1

The equipment used in this example is a tandem extruder consisting of a 30 mm diameter twin screw primary extruder and a 40 mm diameter single screw secondary extruder. The primary extruder includes a feeding section, a melting section, and a mixing section, and the secondary extruder consists of a cooling section.

For 12kg/hr of propylene-ethylene random copolymer resin (Tm=140℃, melt index=0.25), 3kg/hr of iso-butane as a foaming agent is constantly supplied to the primary extruder to melt and melt the resin and foaming agent. mixed. Afterwards, the temperature of the melt was maintained at 100°C for 3 minutes in the secondary extruder, then maintained at 140°C for 10 minutes, and porous organic polymer particles were manufactured by passing through a die with a diameter of 10 mm at the end of the extruder. The average diameter of the prepared porous organic polymer particles was found to be about 7.23 mm, and the pore size was found to be distributed between 50 and 100 ㎛ when observed using scanning electron microscopy and appeared to have open pores.

<Preparation Example 9> Preparation of porous organic polymer particles 2

A polymer solution was prepared by dissolving 2 g of polycaprolactone (PCL, Sigma-Aldrich) with a number average molecular weight of 80,000 g/mol and 0.5 g of tetradecane in 40 g of methylene chloride. The polymer solution was added dropwise to an aqueous solution containing 2% by mass of polyvinyl alcohol and gently stirred to prepare polymer particles with an average diameter of about 370 ㎛.

The polymer particles were placed in an ethanol bath at 4°C and stirred to extract tetradecane. The polymer particles from which tetradecane was extracted were washed several times with distilled water and dried under vacuum to prepare porous organic polymer particles. When observed using scanning electron microscopy, the pore size ranged from 5 to 70㎛ and appeared to have open pores.

<Example 1> Preparation of porous hybrid catalyst 1

A dispersion was prepared by mixing the composite catalyst particles 1 prepared in Preparation Example 1 in an aqueous solution to 10% by weight and milling. The average particle diameter of the milled composite catalyst particles was 0.8 ㎛.

After the coating slurry was dip coated on the surface of the porous organic polymer particles prepared in Preparation Example 8 for 5 minutes, excess slurry was removed by blowing air and dried sufficiently. The immersion and drying process was repeated 10 times, and the coated porous organic polymer particles were charged into a high-temperature furnace and then heat-treated at 60°C for 4 hours to finally prepare porous hybrid catalyst 1.

<Example 2> Preparation of porous hybrid catalyst 2

A porous hybrid catalyst 2 was prepared in the same manner as in Example 1, except that composite catalyst particles 2 prepared in Preparation Example 2 were used instead of composite catalyst particles 1 prepared in Preparation Example 1.

<Example 3> Preparation of porous hybrid catalyst 3

Porous hybrid catalyst 3 was prepared in the same manner as in Example 1, except that composite catalyst particles 3 prepared in Preparation Example 3 were used instead of composite catalyst particles 1 prepared in Preparation Example 1.

<Example 4> Preparation of porous hybrid catalyst 4

A porous hybrid catalyst 4 was prepared in the same manner as in Example 1, except that composite catalyst particles 4 prepared in Preparation Example 4 were used instead of composite catalyst particles 1 prepared in Preparation Example 1.

<Example 5> Preparation of porous hybrid catalyst 5

Porous hybrid catalyst 5 was prepared in the same manner as in Example 1, except that composite catalyst particles 5 prepared in Preparation Example 5 were used instead of composite catalyst particles 1 prepared in Preparation Example 1.

<Example 6> Preparation of porous hybrid catalyst 6

Porous hybrid catalyst 6 was prepared in the same manner as in Example 1, except that composite catalyst particles 6 prepared in Preparation Example 6 were used instead of composite catalyst particles 1 prepared in Preparation Example 1.

<Example 7> Preparation of porous hybrid catalyst 7

Porous hybrid catalyst 7 was prepared in the same manner as in Example 1, except that porous organic polymer particles 2 prepared in Preparation Example 9 were used instead of porous organic polymer particles 1 prepared in Preparation Example 8.

<Example 8> Preparation of porous hybrid catalyst 8

A porous hybrid catalyst 8 was prepared in the same manner as in Example 1, except that composite catalyst particles 7 prepared in Preparation Example 7 were used instead of composite catalyst particles 1 prepared in Preparation Example 1.

<Comparative Example 1> Preparation of porous catalyst 1

In Example 1, porous catalyst 1 was prepared using a monolith honeycomb made of cordierite instead of the porous organic polymer particles 1 prepared in Preparation Example 1.

Specifically, a dispersion was prepared by mixing the composite catalyst particles 1 prepared in Preparation Example 1 in an aqueous solution to 10% by weight and milling. Acetic acid was added to the dispersion to adjust the pH to 4, and an inorganic binder silica sol with an average particle diameter of 32 nm was mixed to make up 1% by weight of the dispersion. Then, polyvinyl alcohol, an organic binder, was mixed with the dispersion to make 2% by weight of the dispersion to prepare a slurry for coating.

After the coating slurry was dip coated on the surface of the monolith honeycomb for 5 minutes, excess slurry was removed by blowing air and dried sufficiently. The immersion and drying process was repeated 10 times, and the coated monolith honeycomb was placed in a vacuum oven and dried at 150°C for 1 hour to finally prepare porous catalyst 1.

<Experimental Example 1> EXAFS (Extended X-ray absorption fine structure) analysis

EXAFS (Extended X-ray absorption fine structure) measurements were performed using the 4C and 10C beamlines of the Pohang Accelerator (PLS-II). The EXAFS spectrum was Fourier transformed to obtain a radial distribution function. Figure 3(a) shows composite catalyst particles carrying gold particles with an average particle diameter of 4 nm (Preparation Example 1), and Figure 3(b) shows composite catalyst particles carrying gold particles with an average particle diameter of 10 nm (Preparation Example 2). ), Figure 3(c) shows the diameter distribution function of composite catalyst particles (Preparation Example 3) carrying gold particles with an average particle diameter of 12 nm.

As a result of analyzing the diameter distribution function of the composite catalyst particles according to Preparation Examples 1 to 6, a peak due to Au-O bond was observed in the 1.4 to 1.7 Å range in all cases. On the other hand, no peak due to Au-O bond was observed in the composite catalyst particles according to Preparation Example 7. From this, it can be confirmed that the proximity between the surface of the gold nanoparticle and the porous silica that collects it provides conditions for forming a stable Au-O bond at the interface between the gold nanoparticle and the porous silica, forming Au-O-Si. there is.

Meanwhile, calculating the ratio of the height (DH1) and area (DA1) of the peak with an interatomic distance of 2.57 ± 0.2 Å and the height (DH2) and area (DA2) of the peak with an interatomic distance of 1.85 ± 0.2 Å are as shown in Table 1 below. It was found that

<Experimental Example 2> Analysis of pore characteristics

After degassing at 473 K to 20 μTorr for 12 hours, a nitrogen (N ₂ ) adsorption-desorption test was performed at 77 K using a 3Flex adsorption analyzer (Micromeritics). At this time, the specific surface area and pore characteristics of the composite catalyst particles according to Preparation Examples 1 to 6 were measured using the volume of adsorbed nitrogen gas molecules and the Brunauer-Emmett-Teller (BET) equation, and the results are shown in Table 2 below. Included. Referring to Table 2, the composite catalyst particles according to Preparation Examples 1 to 3 have larger specific surface area, pore volume, and pore diameter than the composite catalyst particles according to Preparation Example 4. This difference is that the composite catalyst particles of Preparation Examples 1 to 3 had gold nanoparticles embedded in a portion of the surface of the porous silica, whereas the composite catalyst particles of Preparation Example 4 had gold nanoparticles embedded in the entire surface of the porous silica. It appears to appear in something that has a structure.

<Experimental Example 3> Durability test

The catalysts of Examples and Comparative Examples were sufficiently submerged in water and 400 W of ultrasonic waves were applied for 60 minutes to perform an accelerated durability test to compare the catalyst residual rates before and after ultrasonic cleaning. In detail, the porous hybrid catalyst before ultrasonic cleaning is treated with an organic solvent to remove the polymer, and then the composite catalyst particles are quantified. The porous hybrid catalyst after ultrasonic cleaning is treated with an organic solvent to remove the polymer, and then the composite catalyst particles are quantified to determine the remaining catalyst. The rate was calculated.

Example 1 Example 5 Example 6 Example 7 Example 8 Comparative Example 1 Catalyst residual rate (%) 97.2% 96.5% 96.2% 98.2% 95.8% 76.2%

As a result of the accelerated durability test, the catalysts of the examples showed a residual rate of composite catalyst particles of 95% to 99%, but in the case of Comparative Example 1, the residual rate of the catalyst was about 76%. This excellent retention rate is due to the viscoelasticity of the porous organic polymer particles, and the viscoelastic organic polymer absorbs and dissipates mechanical external force, thereby preventing the composite catalyst particles from detaching from the surface of the porous organic polymer particles. On the other hand, in the case of Comparative Example 1, the monolith honeycomb was unable to dissipate mechanical external force, so the composite catalyst particles seemed to be easily separated from the monolith honeycomb. From this, it was shown that the porous hybrid catalyst of the example had excellent durability even under various mechanical external forces.

<Experimental Example 4> Carbon monoxide oxidation characteristics

Carbon monoxide (CO) oxidation was performed in a tubular reactor open on both sides. The porous hybrid catalyst and the porous catalyst according to the examples and comparative examples were airtightly filled in the middle of a tubular reactor, a carbon monoxide-containing gas was supplied to one side of the reactor, and the other side of the reactor was monitored with an infrared measurement continuous gas analyzer (Siemens, ULTRAMAT 23). was connected to measure the carbon monoxide concentration. The carbon monoxide-containing gas used was 0.1% or 1% CO, 10% O ₂ , and the remaining He, and the concentration of carbon monoxide discharged from the other side of the reactor was measured while adjusting the supply flow rate at room temperature (20°C). Table 4 shows the carbon monoxide removal rate according to the concentration and space velocity of the introduced carbon monoxide (=supplied flow rate per 1L of catalyst).

Referring to Table 4, Examples 1 to 3 and Examples 5 and 6 all showed a 100% removal rate under the conditions of a carbon monoxide concentration of 0.1% and a space velocity of 12,000 hr ^-1 , even though air was simply circulated through a pump at room temperature. However, carbon monoxide was completely removed.

Meanwhile, at a higher space velocity of 24,000 hr ^-1 , Examples 1, 5, and 6 showed very good removal rates, while Example 3 showed a somewhat lower removal rate. Example 8 showed that the removal rate through the carbon monoxide oxidation reaction at room temperature was low at all space velocities.

Through this, it can be seen that the porous composite structure catalyst according to one embodiment can effectively remove harmful gases contained in the air even when air containing harmful substances is supplied at a high flow rate at room temperature.

As described above, in this specification, the present disclosure has been described with specific details and limited examples, but these are provided only to facilitate a more general understanding of the present disclosure, and the present disclosure is not limited to the above embodiments. Anyone skilled in the art can make various modifications and variations from this description.

Therefore, the idea described in this specification should not be limited to the described embodiments, and all claims that are equivalent or equivalent to this claim as well as the later-described claims fall within the scope of the idea described in this specification. They will say they do it.

10: Gas containing harmful gases
20: Gas from which harmful gases have been removed
100: Porous hybrid catalyst
110: Core containing porous organic polymer particles
120: Composite catalyst particle layer
121: Porous support
122: Nanoparticles containing metal
200: reaction filter unit
300: inlet
400: outlet

Claims (17)

A core containing porous organic polymer particles; and
A composite catalyst particle layer located on the surface of the core and including a porous support including mesopores and nanoparticles containing a metal incorporated in the pores of the porous support;
A porous hybrid catalyst comprising.
According to paragraph 1,
A porous hybrid catalyst wherein the porous organic polymer particles include macro pores.
According to paragraph 1,
A porous hybrid catalyst wherein the glass transition temperature of the porous organic polymer particles has a value of 300K or less.
According to paragraph 1,
A porous hybrid catalyst, wherein the average pore size of the porous organic polymer particles is larger than the particle size of the composite catalyst particles.
According to paragraph 1,
The porous support is a porous hybrid catalyst that is a metal oxide or metalloid oxide porous support.
According to paragraph 1,
The metals of the nanoparticles include gold (Au), silver (Ag), nickel (Ni), copper (Cu), cobalt (Co), palladium (Pd), platinum (Pt), rhodium (Rh), and ruthenium (Ru). , a porous hybrid catalyst selected from the group consisting of iridium (Ir), molybdenum (Mo), and oxides thereof.
According to clause 6,
A porous hybrid catalyst in which the metal of the nanoparticles is gold (Au).
According to paragraph 1,
A porous hybrid catalyst in which the nanoparticles are incorporated into a portion of the mesopores of the porous support, and the mesopores in which the nanoparticles are not incorporated are connected to each other through open pores.
According to paragraph 1,
A porous hybrid catalyst wherein the composite catalyst particles are physically incorporated into the surface of the core.
According to paragraph 1,
A porous hybrid catalyst wherein the composite catalyst particles are chemically bonded to the surface of the core.
According to paragraph 1,
A porous hybrid catalyst in which the diameter distribution function obtained by Fourier transforming the extended X-ray absorption fine structure (EXAFS) spectrum of the composite catalyst particles satisfies the following equation 1.
[Equation 1]
(DH2/DH1) < 0.3
In the above equation 1, DH1 is the height of the peak at the interatomic distance D1, DH2 is the peak height at the interatomic distance D2, and D1 and D2 satisfy the following equations 2 and 3, respectively:
[Equation 2]
0.8≤(D1/D3)≤0.95
[Equation 3]
0.6≤(D2/D3)≤0.7
(D3 in Equations 2 and 3 above means the interatomic distance of the Au-Au bond in the bulk phase existing at 2.8 to 3.0 Å)
According to clause 11,
The composite catalyst particle is a porous hybrid catalyst that satisfies Equation 4 below.
[Equation 4]
(DA2/DA1) < 0.25
(In the above equation 4, DA1 is the area of the peak at the interatomic distance D1, DA2 is the area of the peak at the interatomic distance D2, and D1 and D2 satisfy the above equations 2 and 3, respectively)
According to clause 11,
A porous hybrid catalyst having a bimodal peak in the interatomic distance range of 2.2 Å to 3.0 Å of the diameter distribution function.
According to paragraph 1,
The porous hybrid catalyst is a porous hybrid catalyst for the oxidation reaction of carbon monoxide, aldehyde-based compounds, or hydrocarbon-based compounds.
A reaction filter unit having an internal space and filled with a plurality of porous hybrid catalysts in the internal space;
an inlet provided on one side of the reaction filter unit through which gas containing harmful gases flows; and
an outlet provided on the other side of the reaction filter unit through which gas from which harmful gases have been removed is discharged;
Includes,
The porous hybrid catalyst is an air purifying filter, characterized in that it is a porous hybrid catalyst according to any one of claims 1 to 14.
According to clause 15,
An air purification filter further comprising a particle filter unit for removing fine particles between the reaction filter unit and the inlet.
(S1) preparing porous organic polymer particles;
(S2) preparing a dispersion containing composite catalyst particles including a porous support including mesopores and nanoparticles containing metal incorporated in the pores of the porous support;
(S3) applying the dispersion to the surface of the porous organic polymer particles; and
(S4) drying the dispersion;
Method for producing a porous hybrid catalyst comprising.