Oxidation catalyst comprising gold particles

Abstract

A pollutant oxidation catalyst according to an embodiment of the present invention comprises: a titanium oxide containing manganese; and gold (Au) in the form of particles supported on the titanium oxide containing manganese. The pollutant oxidation catalyst according to an embodiment of the present invention can effectively remove one or more air pollutants selected from the group consisting of volatile organic compounds (VOC) and carbon monoxide.

Description

Oxidation catalyst containing gold particles

[0001] The present invention relates to an oxidation catalyst comprising gold particles that remove contaminants by an oxidation reaction.

[0002] Pollutants emitted from various industrial processes are becoming a serious social problem, causing environmental pollution and various diseases. These pollutants are also the source of numerous public complaints, necessitating effective treatment methods. Meanwhile, pollutants entering enclosed spaces, such as residential spaces like homes, hotels, and restaurants, or transportation systems like cars and subways, can directly harm the human body and cause discomfort. Furthermore, these pollutants can contaminate various items within these enclosed spaces, leading to secondary problems. Therefore, technologies are needed to consistently remove pollutants from these enclosed spaces to an appropriate level.

[0003] However, chemical equipment for pollutant removal poses safety concerns. In particular, it is difficult to install chemical equipment for pollutant removal in enclosed spaces, so adsorbents are used to remove pollutants. However, adsorbents have limited adsorption capacity, requiring regeneration or periodic replacement. However, in practice, it is difficult for consumers to regenerate adsorbents, requiring periodic replacement. Furthermore, in enclosed environments where pollutant emissions are variable, the lifespan of adsorbents is inconsistent, easily contaminating nearby items and causing inconvenience during use.

[0004] While catalyst-based contaminant removal technologies offer the advantage of not requiring periodic replacement, they suffer from a significant decline in catalytic activity under conditions such as low temperatures or humid environments, resulting in a very short catalyst lifespan. Consequently, there is a growing need for oxidation catalysts capable of maintaining consistent catalytic activity under a variety of harsh conditions, enabling reliable, long-term contaminant removal.

[0005] According to one embodiment of the present invention, an oxidation catalyst capable of effectively removing pollutants can be provided.

[0006] According to another embodiment of the present invention, an oxidation catalyst having improved activity against pollutants under harsh conditions including a humid environment or a low-temperature environment can be provided.

[0007] According to another embodiment of the present invention, a long-life oxidation catalyst capable of reliably removing pollutants for a long period of time can be provided.

[0008] The objectives of the present invention are not limited to the above-described scope. Those skilled in the art will have no difficulty understanding the additional objectives of the present invention from the overall content of this specification.

[0009] A pollutant oxidation catalyst according to one embodiment of the present invention comprises a titanium oxide containing manganese and particulate gold (Au) supported on the titanium oxide containing manganese.

[0010] In one specific example, the manganese-containing titanium oxide may be a manganese-doped titanium oxide.

[0011] In one specific example, the gold particles may have a diameter of 1 to 5 nm.

[0012] In one specific example, in the transmission electron microscope image of the oxidation catalyst, the gold density, which is the number of gold nanoparticles per unit area, is 1000 to 5000 / ㎛. 2 It could be.

[0013] In one specific example, the pollutant oxidation catalyst may contain 0.1 to 1.5 wt% of gold based on the total weight of the pollutant oxidation catalyst.

[0014] In one specific example, the manganese content of the manganese-doped titanium oxide may be 1 to 15 wt%.

[0015] In one specific example, the absorbance (A) at a wavelength of 500 nm in the UV-Vis spectral spectrum of the oxidation catalyst 500 ) at a wavelength of 300 nm, the absorbance (A 300 ) divided by the ratio (A) 500 / A 300 ) can be greater than 0.85.

[0016] In one specific example, in the O 1s X-ray photoelectron spectroscopy spectrum (XPS) of the oxidation catalyst, the oxidation catalyst has a lattice oxygen peak derived from lattice oxygen, an adsorbed oxygen peak derived from surface-adsorbed oxygen, and a hydroxy peak derived from hydroxy radicals, and the ratio of the sum of the area of ​​the hydroxy peak (O3) and the area of ​​the adsorbed oxygen peak (O2) divided by the area of ​​the lattice oxygen peak (O1) ([O2+ O3] / O1×100, %) may be 10 to 50%.

[0017] In one specific example, in the hydrogen temperature reduction profile of the oxidation catalyst, a peak may be located in a temperature range of 240 to 280°C.

[0018] In one specific example, in the X-ray diffraction pattern of the oxidation catalyst, a diffraction peak due to the athanase phase and a diffraction peak due to the rutile phase may exist.

[0019] In one specific example, the maximum intensity I of the (101) plane diffraction peak of the anatase phase 101 The maximum intensity of the diffraction peak I on the Athanase (200) plane 200 Intensity ratio divided by (I 101 / I 200 ) may be less than or equal to 4.15.

[0020] In one specific example, the pollutant may include an air pollutant selected from the group consisting of volatile organic compounds and carbon monoxide.

[0021] A method for removing a pollutant according to another embodiment of the present invention comprises the step of contacting a gaseous phase containing a pollutant with the aforementioned pollutant oxidation catalyst.

[0022] In one specific example, the gas containing the pollutant may contain moisture.

[0023] In one specific example, upon contact with the pollutant oxidation catalyst, the oxidation catalyst may be irradiated with visible light or ultraviolet light.

[0024] In one specific example, the pollutant may include an air pollutant selected from the group consisting of volatile organic compounds and carbon monoxide.

[0025] An oxidation catalyst according to one embodiment can effectively remove pollutants under harsh conditions such as low temperature or humid environment.

[0026] According to another embodiment, an oxidation catalyst can maintain constant catalytic activity under harsh conditions and remove pollutants for a long period of time.

[0027] Figure 1 is a transmission electron microscope image of the manganese-doped titanium oxide (support) manufactured in Example 1.

[0028] Figure 2 is a transmission electron microscope image of the oxidation catalyst 1 manufactured in Example 1.

[0029] Figure 3 is an EDS Au mapping image observing the oxidation catalyst 5 manufactured in Example 5.

[0030] Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings. However, the embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

[0031] In addition, the embodiments of the present invention are provided to more completely explain the present invention to a person having average knowledge in the relevant technical field.

[0032] The shape and size of elements in the drawing may be exaggerated for clearer explanation.

[0033] In describing the embodiments of the present invention, if a detailed description of a known technology related to the present invention is judged to unnecessarily obscure the gist of the present invention, such detailed description will be omitted. In addition, the terms described below are terms defined in consideration of their functions in the present invention, and these may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout this specification. The terminology used in the detailed description is only for the purpose of describing the embodiments of the present invention and should in no way be limiting. Unless clearly defined otherwise, expressions in the singular form include plural meanings.

[0034] In this description, expressions such as "including" or "having" are intended to indicate certain features, numbers, steps, operations, elements, portions or combinations thereof, and should not be construed to exclude the presence or possibility of one or more other features, numbers, steps, operations, elements, portions or combinations thereof other than those described.

[0035] Unless otherwise specified in the specification of the present invention, the % unit means weight %.

[0036] Throughout the specification, when we say that a part is 'connected' to another part, this includes not only cases where it is 'directly connected', but also cases where it is 'indirectly connected' with other elements in between.

[0037] Below, the present invention will be described in detail through each embodiment or example of the present invention. It should be noted that each embodiment or example described in this specification is not limited to a single embodiment or example, but may be combined with other embodiments or examples. Therefore, the citation of a claim in the patent claims is only an example of an embodiment, and the technical concept of the present invention should not be interpreted solely as a combination with the cited claim, and combinations with various claims also fall within the scope of the technical concept of the present invention.

[0038] In this specification, the pollutant is not particularly limited as long as it is known to cause an unpleasant odor or pollute the air, soil or water, but a more advantageous effect can be obtained for gaseous pollutants. Specifically, the gaseous pollutant may be one or more substances selected from the group of volatile organic compounds (VOCs) and carbon monoxide. As the VOCs, representative VOCs that cause unpleasant odors, such as aldehyde compounds, aromatic hydrocarbon compounds, aliphatic hydrocarbon compounds, ammonia compounds or mercaptan compounds, may be mentioned, and specific examples of VOCs may include, but are not limited to, ethylene, formaldehyde, toluene, benzene, xylene, styrene, ethylbenzene, acetaldehyde, trimethylamine or methyl mercaptan.

[0039] In this specification, titanium oxide may mean titanium dioxide, and may be expressed by the chemical formula TiO2, but does not necessarily mean a material in which Ti and O have a mathematically strict integer ratio of 1:2. As is well known, the ratio of Ti and O may deviate from 1:2 to some extent due to the inclusion of unavoidable impurities, doping of metal elements, unavoidable defects, and / or adsorbed oxygen species or radicals. As a non-limiting example, titanium oxide is TiO 2-x, and x can be from 0 to 0.5, from 0 to 0.4, from 0 to 0.3, from 0 to 0.2, or from 0 to 0.1.

[0040] In the present specification, the titanium oxide containing manganese is not limited to being interpreted as containing only manganese, but rather as containing manganese. The titanium oxide containing manganese may be a titanium oxide containing a transition metal containing manganese. As a specific example, the titanium oxide may further contain, together with manganese (Mn), at least one metal selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), and zinc (Zn). As an advantageous example, the titanium oxide containing manganese may include a titanium oxide doped with a transition metal containing manganese. As a practical example, the oxidation catalyst may include a manganese-doped titanium oxide, or may include a titanium oxide co-doped with manganese and at least one metal selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), and zinc (Zn). In describing the present invention, manganese-containing titanium oxide can serve as a support for particulate gold (Au), and thus, manganese-containing titanium oxide is also referred to as a support. However, this is only a support for gold, and the dark-doped titanium oxide contained in the oxidation catalyst can be a catalytic material possessing catalytic activity together with gold.

[0041] Oxidation catalyst

[0042] An oxidation catalyst according to one aspect is a pollutant oxidation catalyst, and includes a titanium oxide containing manganese and particulate gold (Au) supported on the titanium oxide containing manganese. Specifically, the oxidation catalyst is a pollutant oxidation catalyst that promotes an oxidation reaction of a pollutant to remove the pollutant, and may include a support of a titanium oxide containing manganese and particulate gold (Au) supported on the support.

[0043] The titanium oxide containing manganese as a support may be a composite in which titanium oxide and manganese or manganese oxide are mixed, a composite in which a film of manganese or manganese oxide is formed covering at least a portion of the surface of the titanium oxide, a composite in which particulate manganese or particulate manganese oxide is positioned on the surface of the titanium oxide, or a titanium oxide doped with a transition metal containing manganese.

[0044] In an advantageous example, the manganese-containing titanium oxide may be a manganese-containing transition metal-doped titanium oxide (hereinafter, manganese-doped titanium oxide). In other words, the manganese-containing transition metal may occupy a substitutional site, an interstitial site, or both a substitutional site and an interstitial site of the titanium oxide, and may be located within the lattice of the titanium oxide.

[0045] When the support is manganese-doped titanium oxide, particulate gold (Au) is loaded onto the manganese-doped titanium oxide, and thus, the oxidation catalyst can exhibit enhanced catalytic activity due to the synergistic effect between the manganese-doped titanium oxide as the support and the particulate gold, and excellent catalytic activity can be stably maintained even in the presence of a large amount of moisture. On the other hand, when the support is in the form of the aforementioned composite, not only is the oxidation catalytic activity of the support itself low, but even when particulate gold is loaded, it may be difficult to generate synergy.

[0046] In a favorable example, the absorbance at 500 nm wavelength in the UV-Vis spectral spectrum of the oxidation catalyst (A 500 ) at a wavelength of 300 nm (A 300 ) divided by the ratio (A) 500 / A 300 ) can be greater than 0.85.

[0047] In detail, the oxidation catalyst is characterized by the absorbance (A) at a wavelength of 500 nm in the UV-Vis spectral spectrum of the oxidation catalyst. 500 ) at a wavelength of 300 nm (A 300 ) divided by the ratio (A)500 / A 300 ) may be 0.87 or greater, 0.88 or greater, or 0.89 or greater, and may be 0.97 or less, 0.95 or less, or 0.93 or less. As a practical example, A 500 / A 300 The value may be from 0.85 to 0.97, more specifically from 0.88 to 0.96, and even more specifically from 0.89 to 0.95.

[0048] A 500 / A 300 is a property that can indicate the degree of electrochemical change due to defects (including oxygen vacancies) and manganese doping in an oxidation catalyst, specifically manganese-doped titanium oxide. A high absorbance of 0.85 or more at 500 nm compared to the absorbance at a wavelength of 300 nm indicates that a large amount of electrochemical change occurs, and may be a property that indicates that the catalytic activity is improved and different from that of titanium oxide.

[0049] Advantageously, the oxidation catalyst is A as mentioned above. 500 / A 300 At the same time, the absorbance at 700 nm wavelength in the UV-Vis spectral spectrum of the oxidation catalyst (A 700 ) at a wavelength of 300 nm (A 300 ) divided by the ratio (A) 700 / A 300 ) may be 0.80 to 0.95, specifically 0.83 to 0.94, more specifically 0.85 to 0.93. A high A ranging from 0.80 to 0.95 700 / A 300 It is an oxidation catalyst, specifically manganese-doped titanium oxide, in which a large amount of electrochemical changes occurred at the deep level due to defects (including oxygen vacancies) and manganese doping. A 500 / A 300 , which may be a property indicating that the catalytic activity is different from and improved by titanium oxide.

[0050] The manganese-doped titanium oxide or oxidation catalyst may contain titanium oxide crystallographically in the anatase phase, and advantageously, may contain both titanium oxides in the anatase phase and the rutile phase. By having the anatase phase and the rutile phase coexist in the manganese-doped titanium oxide or oxidation catalyst, the catalytic performance of the oxidation catalyst can be further improved. The anatase crystal phase and the rutile crystal phase can be confirmed through X-ray diffraction analysis, and when there is one or more diffraction peaks corresponding to the diffraction peak positions(s) of the anatase-phase titanium dioxide and the rutile-phase titanium dioxide defined in the JCPDS, the manganese-doped titanium oxide or oxidation catalyst can be defined as containing the anatase crystal phase and the rutile crystal phase. The crystal size (crystal size of the titanium oxide) based on the X-ray diffraction pattern in the manganese-doped titanium oxide or oxidation catalyst may be, but is not limited to, on the order of 10 to 40 nm.

[0051] The relative contents of the anatase phase and the rutile phase contained in the oxidation catalyst are determined by the maximum intensity I of the (101) plane diffraction peak of the anatase phase titanium dioxide in the X-ray diffraction pattern of the oxidation catalyst. 101 The maximum intensity of the (110) plane diffraction peak of rutile titanium dioxide I 110 Intensity ratio I 101 / I 110 can be directed to. In a specific example, I 101 / I 110 may be 3 to 8, specifically 3 to 7. Titanium oxide in a composite phase in which anatase and rutile phases coexist is advantageous because it can further improve catalytic activity due to the synergistic effect of the two phases. However, it should not be interpreted that the titanium oxide is composed of anatase and rutile phases. The manganese-doped titanium oxide or oxidation catalyst may further include a brookite phase and / or an amorphous phase of titanium oxide.

[0052] X-ray diffraction patterns can indicate macroscopic properties of the crystallinity of oxidation catalysts. The degree of crystallographic deformation / distortion of titanium oxide caused by manganese doping on the parent titanium oxide and by particulate gold, etc., forming an interface on the surface of the manganese-doped titanium oxide, is expressed by the maximum intensity I of the (101) plane diffraction peak (2θ 25.3º) of the anatase phase in the X-ray diffraction pattern of the oxidation catalyst. 101 The maximum intensity of the diffraction peak I on the Athanase (200) plane 200 Intensity ratio divided by (I 101 / I 200 ) can be measured. In one specific example, I 101 / I 200 may be 4.15 or less, specifically 3.00 to 4.15, more specifically 3.50 to 4.10, even more specifically 3.50 to 4.00, even more specifically 3.50 to 3.95, and even more specifically 3.50 to 3.90.

[0053] In an advantageous example, the manganese-doped titanium oxide or oxidation catalyst may contain on its surface one or more active oxygen species selected from the group consisting of surface-adsorbed oxygen and hydroxyl radicals.

[0054] In an advantageous example, the oxidation catalyst has, in an O 1s X-ray photoelectron spectroscopy (XPS) spectrum of the oxidation catalyst, a lattice oxygen peak derived from lattice oxygen, an adsorbed oxygen peak derived from surface-adsorbed oxygen, and a hydroxy peak derived from hydroxy radicals, and an area ratio ([O2+ O3] / O1×100, %) of the sum of the area of ​​the hydroxy peak (O3) and the area of ​​the adsorbed oxygen peak (O2) divided by the area of ​​the lattice oxygen peak (O1) may be 10 to 50%, specifically 20 to 50%, and more specifically 30 to 50%.

[0055] When the oxidation catalyst satisfies an area ratio ([O2+ O3] / O1×100, %) of 10 to 50%, specifically 20 to 50%, and more specifically 30 to 50% in the XPS O 1s spectrum of the oxidation catalyst, the oxidation catalyst can exhibit uniformly high oxidation activity for various VOCs such as aldehyde compounds, aromatic hydrocarbon compounds, aliphatic hydrocarbon compounds, ammonia compounds, or mercaptan compounds, can exhibit more enhanced carbon monoxide oxidation activity, and can maintain oxidation catalytic activity stably for a long period of time even under harsh conditions such as low temperature or humid environments.

[0056] Although not necessarily limited to this interpretation, the area ratio ([O2+ O3] / O1×100, %) in the XPS O 1s spectrum of the oxidation catalyst indicates the oxidation ability (activity as an oxidation catalyst) of the oxidation catalyst for pollutants, and it can be interpreted that the oxidation ability of the oxidation catalyst is enhanced by the synergistic effect between the manganese-doped titanium oxide itself, the gold nanoparticles themselves, the manganese-doped titanium oxide and ultrafine gold nanoparticles, and also by surface-adsorbed oxygen and hydroxyl radicals.

[0057] Furthermore, in the O 1s X-ray photoelectron spectroscopy (XPS) spectrum of the oxidation catalyst, the ratio (O3 / O2×100, %) of the area of ​​the hydroxy peak (O3) divided by the area of ​​the adsorbed oxygen peak (O2) may be 15 to 80%, specifically 15 to 40%.

[0058] An oxidation catalyst satisfying the above-described XPS O1s spectral characteristics exhibits high oxidation activity for various VOCs and excellent moisture resistance, and can exhibit enhanced carbon monoxide removal performance due to a synergistic effect with gold (Au) in the form of ultrafine nanoparticles loaded on manganese-doped titanium oxide, and in particular, can exhibit significantly enhanced photocatalytic activity. At this time, the photocatalytic activity may be visible light to ultraviolet catalytic activity, and the light irradiated to the oxidation catalyst may be light belonging to the visible light to ultraviolet ray. The wavelength band of the visible light may be 400 to 780 nm, the wavelength band of the ultraviolet ray may be 100 to 400 nm, and the ultraviolet ray may include UV-A (315 to 400 nm), UV-B (280 to 315 nm), UV-C (100 to 280 nm), or a combination thereof.

[0059] In one specific example, the oxidation catalyst may have a peak located in a temperature range of 240 to 280°C in the hydrogen temperature-promoted reduction profile of the oxidation catalyst. In the hydrogen temperature-promoted reduction (H2-TPR) profile of the oxidation catalyst, a peak due to the reduction of gold and a peak due to the reduction of a transition metal, specifically manganese, contained in the oxidation catalyst may be located. Specifically, in the H2-TPR profile, the peak due to the reduction of gold may be located at the lowest temperature, and a peak due to the reduction of manganese may be located following the peak due to the reduction of gold. In the oxidation catalyst according to one specific example, the peak due to the reduction of manganese may be located in a temperature range of 240 to 280°C in the hydrogen temperature-promoted reduction profile of the oxidation catalyst. The peak due to reduction of manganese located in the low temperature region of 240 to 280°C, specifically 250 to 270°C, and more specifically 255 to 270°C may be a property determined by the degree of activity of manganese located in the lattice of titanium oxide. In the H2-TPR profile of the oxidation catalyst, since the peak is located in the low temperature region of 240 to 280°C, specifically 250 to 270°C, and more specifically 255 to 270°C, the oxidation catalyst may have high oxidation activity.

[0060] Manganese-doped titanium oxide can have the shape of particles, and the average particle diameter of the particles is the median diameter D by volume. 50 can be defined as, and the average particle diameter is not limited to a specific range. Volume criterion D 50 It means the particle diameter at the point where the cumulative volume % is 50% in the cumulative distribution curve (cumulative distribution curve) accumulated in order of particle diameter. Experimentally, D 50 The cumulative distribution curve including can be obtained by a conventional particle size analyzer using a laser diffraction method or a dynamic light scattering method.

[0061] As a specific example, D of manganese-doped titanium oxide in particle shape 50 The value can be 0.01 μm or more, 0.05 μm or more, 0.1 μm or more, 0.2 μm or more, 0.3 μm or more, 0.4 μm or more, 0.5 μm or more, 0.7 μm or more, 0.8 μm or more, or 1 μm or more, or 1000 μm or less, 800 μm or less, 700 μm or less, 500 μm or less, 100 μm or less, 50 μm or less, 1 μm or less, 0.5 μm or less, or 0.1 μm or less. For example, it can be 0.01 μm to 1000 μm, 0.05 μm to 0.5 μm, 1 μm to 500 μm, 0.01 μm to 0.1 μm, or 0.01 μm to 1 μm. At this time, the particle size (D) of manganese-doped titanium oxide 50 ) is practically the particle size (D) of the oxidation catalyst. 50 ) can correspond to.

[0062] Based on the total weight of the manganese-doped titanium oxide, the manganese-doped titanium oxide may contain 1 to 15 wt%, specifically 3 to 13 wt%, and more specifically 4 to 9 wt% of manganese.

[0063] As described above, the oxidation catalyst may comprise particulate gold supported on a support which is a manganese-containing titanium oxide, advantageously a manganese-doped titanium oxide.

[0064] The particulate gold may include gold nanoparticles. The diameter of the gold nanoparticles may be 1 to 20 nm, specifically 1 to 15 nm, more specifically 1 to 10 nm, and even more specifically 1 to 5 nm, and may be substantially 1 to 4 nm. When gold nanoparticles having a diameter of 1 to 5 nm, specifically ultrafine gold nanoparticles having a diameter of 1 to 4 nm, are loaded onto a support of manganese-doped titanium oxide, the catalytic activity of the oxidation catalyst may be significantly improved due to the interaction between the manganese-doped titanium oxide and the gold nanoparticles, which is advantageous, and the photocatalytic activity of the oxidation catalyst may also be significantly improved, which is advantageous. Experimentally, the diameter of the gold nanoparticles may be calculated from a transmission electron microscope (TEM) or scanning transmission electron microscope (STEM) observation image of the oxidation catalyst, and may be calculated as the diameter of a circle having the same area as the area of ​​the particulate gold in the observation image. Of course, if necessary, particulate gold can be identified from the observation image using an elemental analysis device such as an energy dispersive spectrometer (EDS) equipped on a transmission electron microscope or scanning transmission electron microscope.

[0065] In the transmission electron microscope image of the oxidation catalyst, the gold density, which is the number of gold nanoparticles per unit area, is 1000 to 5000 / ㎛. 2 , specifically 1500 to 5000 / ㎛ 2 , more specifically 2000 to 5000 / ㎛ 2 , more specifically 2500 to 5000 / ㎛ 2 , More specifically, 3000 to 4500 / ㎛ 2 It can be 1000 to 5000 / ㎛ of ultrafine gold nanoparticles with a diameter of 1 to 5 nm, specifically 1 to 4 nm. 2The oxidation catalyst supported on a high density dispersion can be advantageous because the interaction between gold nanoparticles and manganese-doped titanium oxide can occur actively and smoothly, and can exhibit uniform activity over the entire surface of the oxidation catalyst. Experimentally, the gold density can be calculated through a transmission electron microscope (TEM) observation image of the oxidation catalyst. Specifically, the number of gold nanoparticles located in an area of ​​50 nm x 50 nm to 100 nm x 100 nm in an observation image with a magnification of 1 million to 2 million times is calculated, and the number of gold nanoparticles in at least 5 areas, specifically 5 to 10 random areas, is calculated and then averaged to obtain nm 2 Obtain the number of gold nanoparticles and measure them in ㎛ 2 This may be calculated by converting it into the number of gold nanoparticles. When calculating gold density, it is also possible to identify particulate gold from observation images using elemental analysis equipment, such as an energy dispersive spectroscopy (EDAX) equipped on a transmission electron microscope or scanning transmission electron microscope, if necessary.

[0066] Based on the total weight of the pollutant oxidation catalyst, the pollutant oxidation catalyst may contain 0.1 to 1.5 wt%, specifically 0.3 to 1.5 wt%, more specifically 0.5 to 1.3 wt%, and even more specifically 0.7 to 1.3 wt% of gold. The content of gold in the oxidation catalyst is 5 nm or less, advantageously ultrafine gold nanoparticles of 1000 to 5000 / ㎛. 2 This is a content that is advantageous for gold nanoparticles to be dispersed and spaced apart from each other at a high density and supported on a support.

[0067] Gold nanoparticles may be bound (attached) to the surface of a support. In this case, "bound" may refer to a state in which the gold nanoparticles form an interface with the support and are physically integrated. In terms of manufacturing methods, gold nanoparticles may be formed by nucleating and growing on the support (support surface), thereby binding to the support surface. Specifically, the oxidation catalyst may include gold nanoparticles that are positioned on the support surface together with the support, are spaced apart from each other, and are bound to the support.

[0068] The BET surface area of ​​the oxidation catalyst is 30 to 100 m 2 / g, specifically 40 to 60 m 2 / g, but is not limited to this.

[0069] <Method for manufacturing oxidation catalyst>

[0070] One aspect of the present invention relates to a method for producing an oxidation catalyst comprising a titanium oxide containing manganese and particulate gold (Au) supported on the titanium oxide containing manganese, and relates to a method for producing an oxidation catalyst according to the aforementioned embodiment. Accordingly, the method for producing an oxidation catalyst includes all of the contents described above for the oxidation catalyst.

[0071] A method for manufacturing an oxidation catalyst according to one aspect includes a manufacturing step of manufacturing a titanium oxide containing manganese, advantageously a titanium oxide doped with manganese; and a supporting step of supporting particulate gold (Au) on the manganese-doped titanium oxide.

[0072] According to an advantageous example, the steps for producing manganese-doped titanium oxide may include: 1) preparing a dispersion in which titanium oxide particles are dispersed; 2) preparing a precursor solution in which a transition metal precursor including a manganese precursor is dissolved; 3) preparing a mixture by mixing the dispersion and the precursor solution; 4) adjusting the pH of the mixture to a strongly basic range of 10.5 to 12.5; 5) vacuum filtering the mixture in which the pH is adjusted to a strongly basic range to recover a solid; and 6) drying the recovered solid and calcining it at a temperature of 250 to 400°C for 2 to 4 hours.

[0073] Step 1) is a step of preparing a dispersion by dispersing titanium oxide particles in a solvent, and step 2) is a step of preparing a precursor solution by dissolving a transition metal precursor including a manganese precursor in a solvent. The solvent of step S1) and the solvent of step 2) may independently be polar solvents, specifically polar protic solvents. For example, the solvent of step 1) and the solvent of step 2) may independently be (C1-C7) alcohol, water, or a cosolvent thereof, specifically (C1-C4) alcohol, water (including deionized water), or a cosolvent thereof, and more specifically water.

[0074] 1) The titanium oxide particles of the step may be titanium oxide particles in which anatase phase and rutile phase are advantageously mixed. D of the titanium oxide particles 50The particle size may be 0.01 ㎛ or more, 0.05 ㎛ or more, 0.1 ㎛ or more, 0.2 ㎛ or more, 0.3 ㎛ or more, 0.4 ㎛ or more, 0.5 ㎛ or more, 0.7 ㎛ or more, 0.8 ㎛ or more, or 1 ㎛ or more, and may be 1000 ㎛ or less, 800 ㎛ or less, 700 ㎛ or less, 500 ㎛ or less, 100 ㎛ or less, 50 ㎛ or less, 1 ㎛ or less, 0.5 ㎛ or less, or 0.1 ㎛ or less. For example, it may be 0.01 ㎛ to 1000 ㎛, 0.05 ㎛ to 0.5 ㎛, 1 ㎛ to 500 ㎛, 0.01 ㎛ to 0.1 ㎛, or 0.01 ㎛ to 1 ㎛, but is not limited thereto. Titanium oxide particles can be commercially produced in a mixture of anatase and rutile phases. A representative example of such commercial products is P25 (Evonik).

[0075] 2) The transition metal precursor comprising the manganese precursor of step 2 may be a transition metal compound that is soluble in a polar solvent, specifically, a polar protic solvent. As an example based on manganese, the precursor may be one or a combination of two or more selected from the group consisting of manganese acetate (Mn(Ac)2), manganese nitrate (Mn(NO3)2), manganese chloride (MnCl2), manganese acetylacetonate (Mn(acac)2) and hydrates thereof. Advantageously, the manganese precursor may be one or more selected from the organic-based precursors manganese acetate and manganese acetylacetonate.

[0076] 1) The dispersion of step may contain 0.1 to 5 wt%, specifically 0.5 to 4 wt%, of titanium oxide particles, and 2) the precursor solution of step may contain 0.1 to 5 wt%, specifically 0.3 to 3 wt%, of a transition metal precursor, but is not necessarily limited thereto.

[0077] A transition metal precursor including a manganese precursor can be mixed with a titanium oxide dispersed in a solvent while being dissolved in a solvent. In step 3), the mixing between the dispersion and the precursor solution can be performed in consideration of the mass of the titanium oxide contained in the precursor solution and the mass of the transition metal including manganese contained in the precursor solution, and the mixture can be performed such that the transition metal satisfies a range of 1 to 15 wt%, advantageously a range of 1 to 10 wt%, and more advantageously a range of 4 to 9 wt%, based on the total weight of the titanium oxide and the transition metal.

[0078] 4) In step 4), the mixed solution can be adjusted to a pH of 11.0 to 12.5, advantageously a strongly basic range of 11.0 to 12.0, using a pH adjuster. The pH adjuster can be introduced into the mixed solution in a state dissolved in a polar protic solvent, for example, water. The pH adjuster can be a base such as ammonia, an amine compound, a quaternary ammonium compound, an alkali metal hydroxide, or an alkaline earth metal hydroxide, and is preferably an alkali metal hydroxide, more preferably NaOH or KOH, and even more preferably NaOH. The mixed solution whose pH is adjusted to a strongly basic range can be stirred for 10 to 60 minutes, specifically, for 20 to 50 minutes, but is not limited thereto.

[0079] Step 5) is a step for separating and recovering the solid from the mixed solution in which the reaction has been completed. To separate and recover the solid, any separation means known in the art, such as filtration or centrifugation, can be selected without limitation.

[0080] The recovered solid may be dried and calcined in step 6), so that a manganese-doped titanium oxide may be produced. The drying in step 6) may be performed at a temperature of 100 to 200°C, specifically 100 to 150°C. The drying time may be 2 to 24 hours, but is not limited thereto. The calcination in step 6) may be performed at a temperature of 250 to 400°C, advantageously 300 to 350°C, for 2 to 4 hours. The calcination of the dried solid may be performed in air, and the temperature increase rate during drying or calcination may be 1 to 10°C / min, but is not necessarily limited thereto.

[0081] The solid recovered from the mixed solution can be dried in a state in which it is washed with water before drying or in a state in which it is not washed, and advantageously, it can be dried in a state in which it is recovered by solid-liquid separation such as filtration without being washed.

[0082] The step of supporting particulate gold on the manganese-doped titanium oxide, which is a support manufactured in the manufacturing step, may include: 7) preparing a gold precursor solution in which a gold (Au) precursor is dissolved and adjusting the pH of the gold precursor solution to neutral using a pH adjuster; 8) adding and stirring the manganese-doped titanium oxide manufactured into the gold precursor solution, the pH of which has been adjusted to neutral, to prepare a support-precursor mixture; 9) vacuum filtering the support-precursor mixture to recover and dry a solid; 10) dispersing the dried solid in an alcoholic solvent, and then adding and stirring a reducing agent to the dispersion; and 11) recovering and drying the solid from the dispersion in which the reducing agent has been added, and then calcining the solid at a temperature of 250 to 350°C for 1 to 3 hours.

[0083] Step 7) is a step of preparing a gold precursor solution by dissolving a gold precursor in a solvent and adjusting the pH. The gold precursor of step 7) can be any gold compound that dissolves in a polar solvent, specifically a polar protic solvent. Practical examples of gold precursors include, but are not limited to, chloroauric acid, gold chloride, gold bromide, gold iodide, gold thiosulfate, potassium cyanoaurate, or hydrates thereof.

[0084] 7) The solvent of step 7) may be a polar solvent, specifically a polar protic solvent. For example, the solvent of step 7) may be (C1-C7) alcohol, water or a cosolvent thereof, specifically (C1-C4) alcohol, water (including deionized water) or a cosolvent thereof, and more specifically water. The pH adjusting agent used to adjust the pH of the gold precursor solution to neutrality (pH 6.5 to 7.5) may be a base such as ammonia, an amine compound, a quaternary ammonium compound, an alkali metal hydroxide or an alkaline earth metal hydroxide, and preferably an alkali metal hydroxide, more preferably NaOH or KOH, and even more preferably NaOH.

[0085] 7) The gold precursor solution of step 7 may contain 0.1 to 10 wt%, specifically 0.1 to 5 wt%, of the gold precursor, but is not necessarily limited thereto.

[0086] 8) The amount of the support added to the gold precursor solution in step 8 may be mixed so that the gold content is 0.1 to 1.5 wt%, specifically 0.3 to 1.5 wt%, and more specifically 0.5 to 1.3 wt%, based on the total weight of the manganese-doped titanium oxide and gold, taking into account the mass of gold contained in the gold precursor solution. If necessary, after adding and mixing the support to the gold precursor solution, the pH may be adjusted back to neutral (pH 6.5 to 7.5) using a pH adjuster.

[0087] 9) In step 9, the support-precursor mixture is vacuum filtered to recover the solid content, and the solid content can be dried at a temperature of room temperature to 50°C in an unwashed state.

[0088] The dried solid obtained in step 9) can be dispersed in an alcoholic solvent and mixed with a reducing agent in step 10). In step 10), the solid can be dispersed in an alcoholic solvent at a level of 5 to 30 wt%, but is not limited thereto.

[0089] 10) In step 10, the alcohol solvent may be a (C1-C7) alcohol, more specifically a (C1-C3) alcohol, and for practical examples, may be methanol, ethanol, propanol, n-propanol, isopropanol, or a mixture thereof. An alcohol solvent is advantageous because it can further enhance the reducing power of the reducing agent.

[0090] In step 10), the reducing agent may be a strong reducing agent having a strong reducing power. Specific examples of the strong reducing agent include NaBH₄, LiAlH₄, N₂H₄, or a mixture thereof. The reducing agent may be added to the dispersion (a dispersion in which solids are dispersed in an alcohol-based solvent) such that the molar ratio of gold: reducing agent is 1:1.5 to 5, specifically 1:2 to 4, based on the number of moles of gold contained in the gold precursor solution in step 7). After the reducing agent is added to the dispersion, the dispersion may be stirred for 10 to 60 minutes, specifically 20 to 50 minutes, but is not limited thereto.

[0091] Thereafter, in step 11), the solid content may be recovered from the dispersion liquid into which the reducing agent has been added through a conventional solid-liquid separation means such as vacuum filtration, and the recovered solid content may be washed with water and alcohol, and then the washed solid content may be dried. The drying may be performed at a temperature of 50 to 90°C, but is not limited thereto. The calcination in step 11) may be performed at a temperature of 250 to 350°C, advantageously 280 to 320°C, for 1 to 2 hours. The calcination of the dried solid content may be performed in the air, and the temperature increase rate during the calcination may be 1 to 10°C / min, but is not necessarily limited thereto.

[0092] Through the steps 1) to 11) described above, ultra-fine gold nanoparticles of 5 nm or less, and substantially 1 to 4 nm in size, can be formed at a high density on a support of manganese-doped titanium oxide.

[0093] <Contaminant remover>

[0094] Another aspect of the present invention relates to a contaminant removal agent comprising a manganese-containing titanium oxide and particulate gold (Au) supported on the manganese-containing titanium oxide. The contaminant removal agent may include the oxidation catalyst of the aforementioned embodiment. Accordingly, the contaminant removal agent includes all of the properties described above for the oxidation catalyst.

[0095] In one specific example, the pollutant removal agent may be an oxidation catalyst. The pollutant removal agent may include oxidation catalyst particles (powder), aggregates of particulate oxidation catalysts, or molded articles of oxidation catalysts formed into a desired shape. In this case, the shape of the molded article of the oxidation catalyst may be any shape commonly used in the field of removing pollutants using catalysts. Practical examples of the molded article include, but are not limited to, bulk forms, spherical particle forms, cylindrical or ring-shaped pellet forms, honeycomb forms, and fiber forms.

[0096] In one specific example, the pollutant remover may be a coating product in which the above-described oxidation catalyst is coated on a support. The support may be a ceramic support such as alumina, silicon nitride, silica, zeolite, etc.; a metal support such as stainless steel, etc.; a carbon-based support such as activated carbon, etc.; or an organic support such as a synthetic resin, a natural polymer, a biocompatible polymer, a thermosetting resin, a thermoplastic resin, or a mixed resin thereof, etc. The shape of the support is not particularly limited, but may include a honeycomb shape, a spherical, cylindrical or ring-shaped pellet shape, a plate shape, a porous mesh or porous foam shape, a woven or non-woven fiber shape, etc. In a more practical example, the pollutant remover may include a fabric, filter, film or fiber, etc. in which the above-described oxidation catalyst is contained on the surface or inside. In this case, the filter may be a gas treatment filter, and the gas may include air (atmosphere), etc.

[0097] The contaminant remover can be manufactured by a method commonly used for coating a catalyst material on a support, such as immersion, spraying, or slurry coating, and the contaminant remover can contain 5 to 50 wt% of an oxidation catalyst based on the total weight of the support and the oxidation catalyst, but is not limited thereto. At this time, it goes without saying that a binder component can be used to stably fix the oxidation catalyst to the support, if necessary.

[0098] <Method of removing contaminants>

[0099] One aspect of the present invention relates to a method for removing a pollutant, comprising the step of contacting a gaseous phase containing the pollutant with a pollutant oxidation catalyst comprising a titanium oxide containing manganese and particulate gold (Au) supported on the titanium oxide containing manganese. The pollutant removal method may utilize the oxidation catalyst of the aforementioned embodiment. Accordingly, the pollutant removal method includes all of the features described above regarding the oxidation catalyst.

[0100] A method for removing a pollutant according to one specific example may include: S1) a step of supplying a first gas containing a pollutant to a reaction space in which an oxidation catalyst containing a titanium oxide containing manganese and particulate gold (Au) supported on the titanium oxide containing manganese is positioned; S2) a step of causing the pollutant in the first gas to come into contact with the oxidation catalyst so that the pollutant is decomposed by an oxidation reaction; and S3) a step of discharging a second gas generated by the decomposition of the pollutant from the reaction space.

[0101] The oxidation catalyst within the reaction space may be a fluidized bed or a fixed bed, and as a practical example, a predetermined region of the reaction space may be filled with the oxidation catalyst or an oxidation catalyst in the form of the aforementioned pollutant remover.

[0102] The primary gas may be, but is not limited to, air (atmosphere) containing pollutants or exhaust gases from industrial facilities containing pollutants.

[0103] The reaction space may be an open space into which a first gas may be introduced and a second gas may be discharged. The open space may be implemented through, but is not limited to, opening(s) that connect the inside and the outside of the reactor that defines the reaction space. An oxidation catalyst may be positioned inside the reactor, and a first gas may be introduced into the reactor. Contaminants in the introduced first gas may come into contact with the oxidation catalyst inside the reactor, thereby decomposing and removing the contaminants, and generating a second gas from which the contaminants have been removed. The generated second gas may be discharged outside the reactor. Examples of the generated second gas include, but are not limited to, air (atmosphere) from which volatile organic compounds and / or carbon monoxide have been removed, or exhaust gases from industrial facilities.

[0104] The first and second gases can be introduced and discharged into the reaction space by spontaneous flow, such as convection, without the assistance of external devices. Alternatively, the first and second gases can be introduced and discharged into the reaction space by devices that induce conventional gas flow, such as pumps, blowers, or fans that can forcibly introduce and discharge external fluids.

[0105] The primary gas may be, but is not limited to, the air within a sealed device. Non-limiting examples include air (atmosphere) to which a large number of people are exposed, air (atmosphere) that requires forced ventilation, or air (atmosphere) to which vulnerable populations, such as the elderly, are exposed for long periods or repeatedly. More specific examples include air (atmosphere) within buildings such as hospitals, government offices, schools, commercial facilities, and residential facilities, and air (atmosphere) within transportation facilities such as subways, buses, and vehicles.

[0106] Due to the high moisture resistance of the aforementioned oxidation catalyst, the first gas does not require pretreatment to remove moisture. Accordingly, the first gas may contain moisture. For example, the first gas may have a relative humidity of greater than 0 and less than 100%, more typically a relative humidity of 10 to 90%, or even 50 to 90%. This moisture-containing first gas may be supplied to the reaction space.

[0107] Due to the excellent photocatalytic activity of the oxidation catalyst described above, the oxidation catalyst in contact with the first gas can be irradiated with light. The light irradiated to the oxidation catalyst may be light belonging to visible light or ultraviolet light. Specifically, the light irradiated to the oxidation catalyst may include visible light belonging to a wavelength band of 400 to 780 nm. In addition or independently of this, the light irradiated to the oxidation catalyst may include ultraviolet (UV) belonging to a wavelength band of 100 to 400 nm. Specifically, the UV may include UV-A (315 to 400 nm), UV-B (280 to 315 nm), UV-C (100 to 280 nm), or a combination thereof. The intensity of the irradiated light is 1 to 10 mW / cm. 2 The level may be, but is not necessarily limited to, this. The light source of ultraviolet or visible light irradiated to the oxidation catalyst may include a UV lamp, UV LED (Light Emitting Diode), UV laser, mercury discharge lamp, xenon arc lamp, etc., but is not necessarily limited to these artificial light sources. For example, the oxidation catalyst may be supplied with ultraviolet and / or visible light from natural light (sunlight).

[0108] Hereinafter, embodiments of the present invention will be described in detail. However, these are presented as examples and the present invention is not limited thereto, and the present invention is defined solely by the scope of the claims set forth below.

[0109] <Analysis and Evaluation Method>

[0110] X-ray diffraction analysis

[0111] The X-ray diffraction patterns of the target materials were measured using an X-ray diffraction analyzer (SmartLab, Rigaku). XRD analysis was performed using Cu-Kα (wavelength = 0.15406 nm) as an X-ray source by the θ-2θ method, and was performed under the conditions of 40 kV, 20 mA, and 5° / min scan rate. The maximum intensity value of the corresponding diffraction peak was used as the intensity of a single diffraction peak.

[0112] Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS)

[0113] UV-Vis DRS was performed using a UV-Vis diffuse reflectance spectrometer (V-770, JASCO) equipped with an integrating sphere. Spectralon was used for baseline correction. ® A baseline was established using a standard sample, and the absorbance of the analyte was measured by collecting the light reflected from the analyte. The sample (analyte) was 0.5 mm thick when measuring absorbance.

[0114] X-ray photoelectron spectroscopy (XPS)

[0115] XPS spectra were measured for the target material using an X-ray photoelectron spectroscopy analyzer (K-Alpha+, Thermo scientific). Monochromatic X-rays of Al-Kα (1486.6 eV) were used as a light source, and analysis was performed under the conditions of a beam diameter of 200 μm, 12 kV, and 10 mA.

[0116] Hydrogen Temperature Programmed Reduction (H2-TPR)

[0117] H2-TPR analysis was performed on the target substance. For H2-TPR analysis, AutoChem II 2920 (Micromeritics) was used, and 0.1 g of the target substance was charged into a fixed-bed glass reactor with a diameter of 9 mm, and argon gas was flowed at 30 ml / min, and the reactor was pretreated at 100°C for 1 h. Afterwards, a hydrogen / argon mixture gas with a hydrogen concentration of 10% by volume was flowed at 30 ml / min into the glass reactor, and the reactor was heated from 100°C to 800°C at a rate of 10°C / min using an electric furnace. The amount of unreacted hydrogen was measured using a thermal conductivity detector (TCD, Micromeritics). The H2-TPR profile is the profile of the TCD signal according to temperature (°C). The peaks located in the measured H2-TPR profile were sequentially defined as the first peak and the second peak in the direction from the low temperature side to the high temperature side, and the highest point of the peak in the H2-TPR profile was defined as the position of the corresponding peak.

[0118] Cumulative volume-based median diameter analysis (D 50 )

[0119] 0.1 g of the target substance was suspended in water, and the prepared suspension was sonicated for 2 minutes. Then, the cumulative volume diameter distribution was measured using a laser diffraction particle size distribution measuring device (Mastersizer 2000, Malvern Instruments). The median diameter D of the target substance was 50 In the cumulative volume diameter distribution, it refers to the diameter at the location where the cumulative volume is 50%.

[0120] Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES)

[0121] The composition of the target substance (manganese content in manganese-doped titanium oxide, gold content in the oxidation catalyst, etc.) was analyzed using an Avio 220 Max ICP-OES. The target substance was added to a mixture of nitric acid, hydrochloric acid, and hydrofluoric acid in equal volume ratios, completely dissolved at 180°C, cooled to room temperature, and homogenized (diluted) by mixing with deionized water. The homogenized solution was then used for ICP-OES measurement.

[0122] specific surface area

[0123] After degassing the target material at 473 K to 20 μTorr for 12 h, nitrogen (N2) adsorption-desorption tests were performed at 77 K using a 3Flex adsorption analyzer (Micromeritics). The nitrogen adsorption isotherm and the Brunauer-Emmett-Teller (BET) equation were used to obtain the BET specific surface area of ​​the target material.

[0124] Contaminant removal properties

[0125] Characteristics of VOC removal causing odor: 0.05 g of the catalysts manufactured in the examples and comparative examples were charged into a 1 / 4 inch fixed bed quartz reaction tube, and 300 sccm of air gas containing 50 ppm of methyl mercaptoethanol, 50 sccm of air gas containing 10 ppm of acetaldehyde, 50 sccm of air gas containing 10 ppm of trimethylamine, or 30 sccm of air gas containing 5 ppm of toluene were supplied to one end of the reaction tube, and the other end of the reaction tube was connected to GC-MS (Gas Chromatography-Mass Spectroscopy, Agilent), and the concentration of odor gas discharged from the other end of the reaction tube was measured after 3 hours. In the gas removal characteristic experiment, moisture supply (relative humidity, RH) was supplied (RH~70%) by passing the carrier air gas through a water-filled tube, and the fixed-bed glass reaction tube equipped with a catalyst was maintained at 25°C, and UV-A (365 nm) lamp was used to irradiate UV-A at 30 mW / cm 2 The effect of UV was confirmed by irradiating the catalyst with a century, and the removal rate (conversion) of each gas was calculated according to the following equation 1.

[0126] Equation 1: Conversion (%) = (1-C out / C in ) x 100

[0127] C in Equation 1 in is the concentration of pollutants in the incoming gas (ppm), and C out It is the concentration of pollutants in the exhaust gas at the 3-hour point of the reaction, and is specifically the concentration (ppm) of pollutants in the exhaust gas that passed through the reaction tube after pollutant-containing air was continuously supplied to the reaction tube for 3 hours.

[0128] Carbon monoxide removal characteristics: 0.1 g of the catalysts manufactured in the examples and comparative examples were charged into a 1 / 4 inch fixed-bed quartz reaction tube, and 250 sccm of air gas containing 40,000 ppm of carbon monoxide (CO) was supplied as a gas composition to one end of the reaction tube, and the other end of the reaction tube was connected to a GC-TCD (Gas Chromatography-Thermal Conductivity Detector, DS Science) to measure the concentration of carbon monoxide discharged from the other end of the reaction tube. In the carbon monoxide removal characteristics experiment, moisture supply (relative humidity, RH) was supplied (RH~70%) by passing the carrier air gas through a tube filled with water, and the fixed-bed glass reaction tube equipped with the catalyst was maintained at 0℃ using an ice jacket, and the removal rate (Conversion) of carbon monoxide was calculated according to the following equation 2.

[0129] Equation 2: Conversion (%) = (1-C out / C in ) x 100

[0130] C in Equation 2 in is the concentration of carbon monoxide inflow (ppm), C out is the concentration of carbon monoxide (ppm) after passing through the reaction tube.

[0131] (Example 1)

[0132] 900 g of TiO2 (P25, Evonik) was added to 50 L of distilled water and stirred for 15 minutes to prepare a TiO2 dispersion, and 300 g of manganese acetate (MnAc₂·4H₂O, Deoksan) was added to 25 L of distilled water and stirred for 15 minutes to prepare a manganese precursor aqueous solution. Then, the prepared manganese precursor aqueous solution was added to the TiO2 dispersion and stirred for 1 hour to prepare a mixed solution. NaOH aqueous solution was added to the prepared mixed solution to adjust the pH to 11.5 and stirred for 30 minutes. After that, the mixed solution with the adjusted pH was vacuum filtered to recover the solid content, and the recovered solid content was dried at 120°C for 12 hours by increasing the temperature at a rate of 5°C / min. The dried solid powder was heated to 300°C at a rate of 1.5°C / min and calcined in air at 300°C for 3 hours to produce manganese-doped titanium oxide.

[0133] English: 26 g of chloroauric acid (HAuCl4·3H2O, Sigma-Aldrich) was dissolved in 5 L of distilled water, and the pH was adjusted to 7 with an aqueous NaOH solution. 1000 g of the prepared manganese-doped titanium oxide was added and stirred for 1 hour to prepare a support-precursor mixture. The support-precursor mixture was then vacuum-filtered to recover the solid and dried at 40°C for 12 hours. The dried solid was suspended in 5 L of ethanol, and 400 ml of a reducing agent solution containing 0.5 M NaBH4 dissolved in ethanol was added, followed by stirring for 30 minutes. The solid after the reaction was completed was recovered, washed with water and ethanol, and dried (80°C). The dried powder was heated to 300°C at a rate of 1.5°C / min and calcined in air at 300°C for 2 hours to prepare an oxidation catalyst 1.

[0134] The BET surface area of ​​oxidation catalyst 1 is 50.9 m 2 / g and D 50 The thickness was 59 nm, and the manganese content of the manganese-doped titanium oxide as a support was 6.7 wt%. The gold content of the oxidation catalyst 1 was 0.9 wt%.

[0135] (Example 2)

[0136] In the above Example 1, 13 g of chloroauric acid (HAuCl4·3H2O, Sigma-Aldrich) was dissolved in 5 L of distilled water, and 200 mL of a 0.5 M concentration NaBH4 ethanol solution was added to the suspension, and an oxidation catalyst 2 was prepared in the same manner as in Example 1. The gold content of the oxidation catalyst 2 was 0.5 wt%.

[0137] (Example 3)

[0138] In Example 1, an oxidation catalyst 3 was prepared in the same manner as in Example 1, except that the pH was adjusted to 12.0 using an aqueous NaOH solution for pH adjustment for preparing a support, and the support was prepared by calcining at 350°C for 2 hours.

[0139] (Example 4)

[0140] In Example 1, 26 g of chloroauric acid (HAuCl4·3H2O, Sigma-Aldrich) was dissolved in 5 L of distilled water, the pH was adjusted to 7 using an aqueous NaOH solution, 1000 g of the manufactured manganese-doped titanium oxide was added and mixed, the pH was adjusted to 7 again using an aqueous NaOH solution, and the mixture was stirred for 1 hour to prepare a support-precursor mixture, except that an oxidation catalyst 4 was prepared in the same manner as in Example 1.

[0141] (Example 5)

[0142] In Example 1, 26 g of chloroauric acid (HAuCl4·3H2O, Sigma-Aldrich) was dissolved in 5 L of distilled water, the pH was adjusted to 8 using an aqueous NaOH solution, 1000 g of the prepared manganese-doped titanium oxide was added, stirred for 1 hour, and the pH was adjusted to 8 again using an aqueous NaOH solution to prepare a support-precursor mixture. Thereafter, the prepared support-precursor mixture was heated to 70°C and stirred for 3 hours, and the solid content was recovered. The recovered solid content was washed with water and dried (80°C), and the dried powder was heated to 300°C at a rate of 1.5°C / min and calcined in air at 300°C for 2 hours, except that an oxidation catalyst 5 was prepared in the same manner as in Example 1.

[0143] (Comparative Example 1)

[0144] In Example 1, the manganese-doped titanium oxide was not loaded with gold (Au), and the manganese-doped titanium oxide produced in Example 1 itself was used as an oxidation catalyst. Hereinafter, the catalyst of Comparative Example 1 is collectively referred to as Comparative Catalyst 1.

[0145] (Comparative Example 2)

[0146] TiO2(P25, Evonik, D 50 62 nm) was used as an oxidation catalyst. Hereinafter, the catalyst of Comparative Example 2 is collectively referred to as Comparative Catalyst 2.

[0147] (Comparative Example 3)

[0148] Dissolve 26 g of chloroauric acid (HAuCl4·3H2O, Sigma-Aldrich) in 5 L of distilled water and adjust the pH to 8 using an aqueous NaOH solution, then add TiO2 (P25, Evonik, D 5062 nm) was added as a support, 1000 g of TiO2 was stirred for 1 hour, and then the pH was adjusted to 8 using NaOH aqueous solution to prepare a support-precursor mixture. The prepared support-precursor mixture was heated to 70°C and stirred for 3 hours, and then the solid content was recovered. The recovered solid content was washed with water and dried (80°C), and the dried powder was heated to 300°C at a rate of 1.5°C / min and calcined at 300°C for 2 hours to prepare Comparative Catalyst 3.

[0149] Fig. 1 is a transmission electron microscope image (scale bar 50 nm) observing the manganese-doped titanium oxide (support) manufactured in Example 1. As shown in the transmission electron microscope observation results of Fig. 1, no significant difference was found in the shape or primary particle size distribution of the titanium oxide between the titanium oxide (P25) used as a raw material and the support, and no heterogeneous particles or coatings adhered to the surface of the titanium oxide primary particles were substantially observed.

[0150] Fig. 2 is a transmission electron microscope image of the manufactured oxidation catalyst 1. As shown in an example in Fig. 2, it was confirmed that ultrafine gold nanoparticles with an average size of 2.8 nm in the oxidation catalyst 1 were dispersed and bound to the surface of the manganese-doped titanium oxide particles. Similarly to the oxidation catalyst 1, it was also confirmed that ultrafine gold nanoparticles with a size range of 1 to 4 nm were dispersed and bound to the surface of the support in the case of the oxidation catalysts 2 to 4 manufactured in Examples 2 to 4. On the other hand, in the case of the oxidation catalyst 5 manufactured in Example 5, relatively coarse gold nanoparticles of about 100 nm were formed (see the Au EDS mapping image in Fig. 3).

[0151] The gold density was calculated by measuring the number of gold nanoparticles in five areas of 80 nm x 80 nm in transmission electron microscope images of oxidation catalysts 1 to 4 at the same magnification as in Fig. 2. The gold density of oxidation catalyst 1 was 3820 / ㎛. 2and the gold density of oxidation catalyst 2 was 1650 / ㎛. 2 The gold density of oxidation catalyst 3 was 3560 / ㎛. 2 and the gold density of oxidation catalyst 4 was 3290 / ㎛. 2 It was.

[0152] Absorbance (A) at a wavelength of 500 nm in the UV-Vis spectral spectra of the oxidation catalysts manufactured in the examples and comparative examples 500 ) at a wavelength of 300 nm, the absorbance (A 300 ) divided by the ratio (A) 500 / A 300 ) and absorbance at a wavelength of 700 nm (A 700 ) at a wavelength of 300 nm, the absorbance (A 300 ) divided by the ratio (A) 700 / A 300 ) are summarized in Table 1.

[0153] A 500 / A 300 A 700 / A 300 A 500 / A 300 A 700 / A 300 Oxidation catalyst 10.900.88 Oxidation catalyst 50.930.92 Oxidation catalyst 20.900.86 Comparative catalyst 10.970.94 Oxidation catalyst 30.920.88 Comparative catalyst 20.230.25 Oxidation catalyst 40.900.88 Comparative catalyst 30.800.72

[0154] In the O 1s XPS spectra of the oxidation catalysts manufactured in the examples and comparative examples, the ratio of the sum of the area of ​​the hydroxy peak (O3) and the area of ​​the adsorbed oxygen peak (O2) divided by the area of ​​the lattice oxygen peak (O1) ([O2+ O3] / O1×100, %) is 45 to 85%, and the ratio of the area of ​​the hydroxy peak (O3) divided by the area of ​​the adsorbed oxygen peak (O2) (O3 / O2×100, %) is summarized in Table 2. The O 1s XPS spectrum was deconvoluted into a lattice oxygen peak (529.2–529.9 eV) derived from lattice oxygen, an adsorbed oxygen peak (531.2–532.7 eV) derived from surface-adsorbed oxygen, and a hydroxy peak (532.9–533.5 eV) derived from hydroxy radicals, and then fitted with a Gaussian function for deconvolution.

[0155] [O2+O3] / O1×100O3 / O2×100[O2+O3] / O1×100O3 / O2×100Oxidation catalyst 144%19%Oxidation catalyst 527%80%Oxidation catalyst 238%25%Comparative catalyst 178%11%Oxidation catalyst 330%17%Comparative catalyst 218%0%Oxidation catalyst 448%33%Comparative catalyst 319%0%

[0156] As a result of X-ray diffraction analysis of the oxidation catalysts manufactured in Examples and Comparative Examples, peaks due to the anatase phase and peaks due to the rutile phase were detected in all manufactured catalysts, and peaks due to manganese or manganese oxides were not detected. In the X-ray diffraction patterns of the oxidation catalysts 1 to 5 manufactured in Examples, the maximum intensity I of the (101) plane diffraction peak of the anatase phase 101 The maximum intensity of the (110) plane diffraction peak I on rutile 110 Intensity ratio I 101 / I 110 was in the range of 3.41 to 4.01. The maximum intensity I of the (101) plane diffraction peak of the anatase phase in the X-ray diffraction pattern of the titanium oxide (comparative catalyst 2) used as an oxidation catalyst and raw material 101 The maximum intensity of the diffraction peak I on the Athanase (200) plane 200 Intensity ratio divided by (I101 / I 200 ) are summarized in Table 3 below.

[0157] I 101 / I 200 I 101 / I 200 Oxidation catalyst 13.87 Oxidation catalyst 43.76 Oxidation catalyst 23.81 Oxidation catalyst 54.14 Oxidation catalyst 33.57 Comparative catalyst 24.18

[0158] In the H2-TPR profiles of the oxidation catalysts manufactured in the examples and comparative examples, the peaks sequentially positioned in the direction of increasing temperature are designated as the first peak and the second peak, and the peak position (℃) of the first peak, which is the peak positioned at the lowest temperature, and the peak position (℃) of the second peak, which is the peak positioned at the second lowest temperature, are summarized in Table 4 below. In Table 4, the first peak in oxidation catalysts 1 to 5 and comparative catalyst 3 is a peak due to the reduction of gold, and the first peak in comparative catalyst 1 and the second peak in oxidation catalysts 1 to 5 are peaks due to the reduction of manganese contained in the oxidation catalyst.

[0159] First peak position (℃)Second peak position (℃)Oxidation catalyst 1150.1Oxidation catalyst 1259.7Oxidation catalyst 2158.4Oxidation catalyst 2262.5Oxidation catalyst 3148.4Oxidation catalyst 3268.4Oxidation catalyst 4161.6Oxidation catalyst 4266.1Oxidation catalyst 5159.7Oxidation catalyst 5261.9Comparative catalyst 1263.3Comparative catalyst 1369.9Comparative catalyst 2-Comparative catalyst 2-Comparative catalyst 3155.9Comparative catalyst 3-

[0160] The acetaldehyde removal performance, methyl mercaptan removal performance, trimethylamine removal performance, toluene removal performance, and carbon monoxide removal performance of the oxidation catalysts manufactured in the examples and comparative examples are summarized in Tables 5 and 6. All hazardous substance removal experiments were performed under conditions of approximately 70% relative humidity. In the table, when the catalyst was not irradiated with UV-A, it was indicated as UV-off, and when UV-A was irradiated, it was indicated as UV-on.

[0161] PollutantAcetaldehydeAcetaldehydeMethylmercaptanTrimethylamineUVUV-offUV-onUV-offUV-offOxidation catalyst 188%100%100%100%Oxidation catalyst 281%100%100%100%Oxidation catalyst 382%100%100%100%Oxidation catalyst 484%100%100%100%Oxidation catalyst 557%91%100%83%Comparative catalyst 155%94%100%81%Comparative catalyst 20%56%0%0%Comparative catalyst 38%55%12%6%

[0162] PollutantTolueneTolueneCarbon MonoxideUVUV-offUV-onUV-offOxidation Catalyst 1100%100%100%Oxidation Catalyst 2100%100%82%Oxidation Catalyst 395%100%88%Oxidation Catalyst 497%100%87%Oxidation Catalyst 589%99%55%Comparative Catalyst 195%100%0%Comparative Catalyst 20%21%0%Comparative Catalyst 33%37%51%

[0163] As described above, the present invention has been described through specific matters and limited embodiments and drawings, but these are provided only to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains can make various modifications and variations from this description. Therefore, the spirit of the present invention should not be limited to the described embodiments, and all things that are equivalent or equivalent to the following claims as well as the claims are considered to fall within the scope of the spirit of the present invention.

Claims

1. A pollutant oxidation catalyst comprising a titanium oxide containing manganese and particulate gold (Au) supported on the titanium oxide containing manganese.

2. In paragraph 1, The above manganese-containing titanium oxide is a pollutant oxidation catalyst that is manganese-doped titanium oxide.

3. In paragraph 2, A pollutant oxidation catalyst comprising gold nanoparticles having a diameter of 1 to 5 nm.

4. In paragraph 3, In the transmission electron microscope image of the above oxidation catalyst, the gold density, which is the number of gold nanoparticles per unit area, is 1000 to 5000 / ㎛. 2 In, pollutant oxidation catalyst.

5. In paragraph 2, A pollutant oxidation catalyst, wherein the pollutant oxidation catalyst contains 0.1 to 1.5 wt% of gold based on the total weight of the pollutant oxidation catalyst.

6. In paragraph 2, A pollutant oxidation catalyst, wherein the manganese content of the manganese-doped titanium oxide is 1 to 15 wt%.

7. In paragraph 2, Absorbance (A) at a wavelength of 500 nm in the UV-Vis spectral spectrum of the above oxidation catalyst 500 ) at a wavelength of 300 nm, the absorbance (A 300 ) divided by the ratio (A) 500 / A 300 ) is a pollutant oxidation catalyst with an oxidation coefficient of 0.85 or higher.

8. In paragraph 2, In the O 1s X-ray photoelectron spectroscopy spectrum (XPS) of the above oxidation catalyst, it has a lattice oxygen peak derived from lattice oxygen, an adsorbed oxygen peak derived from surface-adsorbed oxygen, and a hydroxy peak derived from hydroxy radicals. A pollutant oxidation catalyst, wherein the ratio of the sum of the area of the hydroxy peak (O3) and the area of the adsorbed oxygen peak (O2) divided by the area of the lattice oxygen peak (O1) ([O2+ O3] / O1×100, %) is 10 to 50%.

9. In paragraph 2, A pollutant oxidation catalyst having a peak located in the temperature range of 240 to 280°C in the hydrogen temperature reduction profile of the above oxidation catalyst.

10. In paragraph 2, A pollutant oxidation catalyst, wherein in the X-ray diffraction pattern of the above oxidation catalyst, a diffraction peak due to an athanase phase and a diffraction peak due to a rutile phase exist.

11. In paragraph 10, The maximum intensity I of the (101) plane diffraction peak of the above anatase phase 101 The maximum intensity of the diffraction peak I on the Athanase (200) plane 200 Intensity ratio divided by (I 101 / I 200 ) is a pollutant oxidation catalyst having an oxidation value of 4.15 or less.

12. In paragraph 1, A pollutant oxidation catalyst, wherein the pollutant comprises an air pollutant selected from the group consisting of volatile organic compounds and carbon monoxide.

13. A method for removing pollutants, comprising the step of contacting a gaseous phase containing pollutants with a pollutant oxidation catalyst according to claim 1.

14. In paragraph 13, A method for removing air pollutants, wherein the gas containing the above pollutants contains moisture.

15. In paragraph 13, A method for removing air pollutants, wherein when the pollutant comes into contact with the oxidation catalyst, visible light or ultraviolet light is irradiated to the oxidation catalyst.

16. In paragraph 13, A method for removing air pollutants, wherein the pollutants include at least one air pollutant selected from the group consisting of volatile organic compounds and carbon monoxide.

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