KR102446719B1 - Surfur compound purification photocatalyst - Google Patents

Abstract

platinum particles; It is a sulfur compound purification catalyst including the composite particles including tungsten oxide particles, wherein the tungsten oxide particles support the platinum particles, and 0.5 g of the sulfur compound purification catalyst is put into a 3L container, sealed and degassed, After injecting a gas containing 1.6 ppm hydrogen sulfide, a sulfur compound purification catalyst having a hydrogen sulfide removal rate of 30 to 99.9% obtained by measuring the concentration 30 minutes after the hydrogen sulfide injection is provided in the absence of light.

Description

Sulfur compound purification catalyst {SURFUR COMPOUND PURIFICATION PHOTOCATALYST}

It relates to a sulfur compound purification catalyst.

As a catalyst material capable of decomposing harmful gases for air purification, there is typically TiO ₂ . TiO ₂ has the advantages of excellent durability and abrasion resistance, a safe and non-toxic material, and low price. On the other hand, since TiO ₂ is activated by light and catalyzed, there is a problem in that it is difficult to utilize it as a catalyst in the absence of light. In addition, under the condition that light is irradiated, the bandgap energy is large, so it can absorb only light below ultraviolet light, so it can be used with a separate ultraviolet supply device or used outdoors where ultraviolet rays are abundant, and used indoors or under LEDs. There are limits.

Recently, the number of companion animal households is on the rise, and accordingly, there is a growing need to solve the odor problem caused by companion animals. Bad odors from companion animals are known to be caused by sulfur compounds. However, TiO ₂ is difficult to expect purification catalysis for these sulfur compounds.

One embodiment of the present invention provides a sulfur compound purification catalyst capable of purifying sulfur compounds in the absence of light.

Another embodiment of the present invention provides a sulfur compound purification catalyst having excellent purification action on sulfur compounds in both conditions with and without light.

In one embodiment of the present invention, platinum particles; It is a sulfur compound purification catalyst including the composite particles including tungsten oxide particles, wherein the tungsten oxide particles support the platinum particles, and 0.5 g of the sulfur compound purification catalyst is put into a 3L container, sealed and degassed, Provided is a sulfur compound purification catalyst having a hydrogen sulfide removal rate of 30 to 99.9% obtained by injecting a gas containing 1.6 ppm hydrogen sulfide and measuring the concentration 30 minutes after injection of the hydrogen sulfide in the absence of light.

In one embodiment of the present invention, the sulfur compound purifying catalyst is, after sealing and degassing by putting 0.5 g of the sulfur compound purifying catalyst in a 3L container, and injecting a gas containing 1.6 ppm hydrogen sulfide, a wavelength of 400 nm to 700 nm Under the condition of irradiating the light of 25,000 lux, the hydrogen sulfide removal rate obtained by measuring the concentration 30 minutes after the hydrogen sulfide injection is 60 to 99.9%.

The sulfur compound purifying catalyst is capable of purifying sulfur compounds in the absence of light.

The sulfur compound purifying catalyst has excellent purifying action on sulfur compounds in both conditions with and without light.

1 is a schematic diagram of particles of a sulfur compound purification catalyst according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail. However, this is presented as an example, and the present invention is not limited thereto, and the present invention is only defined by the scope of the claims to be described later.

In one embodiment of the present invention, platinum particles; It provides a sulfur compound purification catalyst including the composite particles including; tungsten oxide particles.

The sulfur compound purifying catalyst may perform an air purifying action by removing sulfur compounds by adsorption, decomposition or photolysis.

The composite particles may adsorb sulfur compounds.

In addition, the composite particles may decompose the adsorbed sulfur compound. The composite particles can decompose sulfur compounds to a predetermined level even in the absence of light. When the composite particles are irradiated with light, the sulfur compound may be more effectively decomposed by photoactivity.

The sulfur compound purification catalyst has excellent surface adsorption performance for sulfur compounds, so it shows superior removal performance for sulfur compounds than conventional photocatalysts activated by light even in the absence of light, and better removal performance than in the presence of light indicates

In households with companion animals, sulfur compounds produced by companion animals are the cause of bad odors. Since the sulfur compound purification catalyst is effective in removing such sulfur compounds, it may be usefully used as a purification catalyst for removing sulfur compounds in households raising companion animals.

The sulfur compound means a compound containing sulfur, and may include hydrogen sulfide, methyl mercaptan, dimethyl sulfide, dimethyl disulfide, and the like.

The sulfur compound removal performance of the sulfur compound purification catalyst can be known by performance evaluation of hydrogen sulfide, which is a type of representative sulfur compound. Although the sulfur compound purification catalyst shows an evaluation value for the hydrogen sulfide removal rate, this does not mean that only hydrogen sulfide can be removed. In addition to hydrogen sulfide, the sulfur compound purification catalyst has the ability to remove sulfur-containing compounds from the air by adsorption and decomposition, for example, for compounds such as methyl mercaptan, dimethyl sulfide, and dimethyl disulfide. Removal performance can be exhibited.

The "removal" performance includes not only decomposition, but also removal from air by adsorption to the sulfur compound purification catalyst.

In one embodiment, 0.5 g of the sulfur compound purification catalyst is put into a 3L container, sealed and degassed, and then a gas containing 1.6 ppm hydrogen sulfide is injected, and the concentration is adjusted 30 minutes after injection of the hydrogen sulfide in the absence of light. The hydrogen sulfide removal rate obtained by measurement may be about 30 to about 99.9%, specifically about 35 to about 99.9%, and more specifically about 40 to about 99.9%.

The sulfur compound purification catalyst not only achieves an excellent removal rate in the above numerical range in the absence of light, but also when irradiated with light, it is activated by light to more effectively remove sulfide water, so a higher hydrogen sulfide removal rate in a numerical range indicates.

In one embodiment, 0.5 g of the sulfur compound purification catalyst is put into a 3L container, sealed and degassed, a gas containing 1.6 ppm hydrogen sulfide is injected, and then light of a wavelength of 400 nm to 700 nm is irradiated at 25,000 lux. , The hydrogen sulfide removal rate obtained by measuring the concentration 30 minutes after injection of the hydrogen sulfide may be about 60 to about 99.9%, specifically about 65 to about 99.9%, more specifically about 70 to about 99.9%.

The gas containing the hydrogen sulfide input to the 3L container is specifically a gas in which hydrogen sulfide is mixed to a concentration of 1.6 ppm in the atmosphere (total volume of hydrogen sulfide and the atmosphere including the same: volume of hydrogen sulfide = 1,000,000: 1.6). .

The ppm concentration is measured as a volume ratio.

The removal rate refers to the percentage ratio (ppm basis) of hydrogen sulfide removed by setting the input ppm concentration, ie, 1.6 ppm concentration, to 100%.

For example, after the gas containing the hydrogen sulfide is introduced, the container may be at room temperature and atmospheric pressure (25° C., 1 atm).

The composite particles are formed in a form in which nano-sized platinum particles are supported on the surface of the tungsten oxide particles.

The platinum particles are formed by reducing the platinum precursor according to the manufacturing method to be described later. For example, when the platinum precursor is H ₂ PtCl ₆ , the oxidation number of Pt is +4, and these Pt ⁴⁺ ions are reduced to form platinum particles among the composite particles. Among the composite particles, platinum particles must be reduced to have an oxidation number of 0 to effectively decompose, and can also be effectively activated by visible light. Platinum particles having an oxidation number of 0 mean that they are supported in a metallic state, not as an ion.

However, some platinum particles among the composite particles may also have an oxidation number of +2. In the manufacturing process, platinum particles in an ionic state such as Pt ²⁺ produced by incomplete reduction of platinum do not function properly as a co-catalyst during the photocatalytic reaction of the composite particles, but rather interfere with photocatalytic reactions such as harmful gas removal reactions. lowers the overall efficiency. That is, the platinum particles supported in an ionic state may cause deterioration in performance because they interfere with the photocatalytic reaction of the composite particles as a catalyst for purifying sulfur compounds. In addition, if the content of the platinum particles supported in the ionic state increases, it can be seen that the expensive platinum precursor is wasted.

The composite particles have a high content of platinum particles having an oxidation number of 0, and thus have excellent removal performance of sulfur compounds.

1 is a cross-sectional view schematically showing a composite particle 10 according to an embodiment of the present invention.

In FIG. 1 , the composite particle 10 includes a tungsten oxide particle 1 and a platinum particle 2 .

The composite particle 10 is a material capable of air cleaning, deodorization, and antibacterial action by generating surface active oxygen such as superoxide anions or hydroxy radicals by electrons and holes generated from energy obtained by absorbing light. For example, the superoxide anion or hydroxy radical generated by the photoactive action of the composite particles can decompose harmful substances such as acetaldehyde, ammonia, formaldehyde, acetic acid, TVOC, etc., and Antibacterial action against bacteria is possible.

Since the composite particles 10 can be activated not only by ultraviolet light but also by visible light, they can exhibit excellent efficiency even in an indoor light source, and thus a separate ultraviolet light supply device may not be required.

The tungsten oxide particles 1 may be formed into spherical, plate-shaped, or needle-shaped particles by, for example, a sol-gel method or a hydrothermal method as a carrier, but there is no limitation in the shape thereof.

The tungsten oxide particles 1 can adsorb and decompose sulfur compounds even in the absence of visible light, and exhibit better active performance when irradiated with visible light.

The platinum particles 2 may be supported on the porous metal oxide by a photo-deposition method, but is not limited thereto.

The platinum particles 2 may facilitate separation of electrons and holes from energy obtained by absorbing light.

The average diameter of the tungsten oxide particles 1 used in the manufacture of the composite particles 10 can be calculated by electron microscopy measurement such as SEM image analysis, for example, the average diameter is about 30 nm to about 500 nm that can be used If the average diameter of the tungsten oxide particles 1 is too large beyond the above range, it is difficult to form a stable coating solution when the powder of the sulfur compound purification catalyst is dispersed in a solvent, so that a filter using the sulfur compound purification catalyst is manufactured In this case, it may not be suitable for the process of coating the sulfur compound purification catalyst. If the diameter of the tungsten oxide particles 1 is too small to be less than the above range, it may be difficult to stably support the platinum particles 2 .

The average particle diameter of the composite particles 10 is about 1 μm or less, and specifically, may be about 0.2 μm to about 1 μm, for example, about 0.4 μm to about 0.5 μm. The average particle diameter of the composite particles 10 may be obtained by measuring about 4 wt% aqueous dispersion of the sulfur compound purification catalyst with a particle size analyzer (Beckman, LS 13 320). In addition, the maximum particle diameter of the composite particle 10 is set to be about 10 μm or less.
The platinum particles may have a diameter of 1 nm to 10 nm.

The composite particle 10 may include 100 parts by weight of the tungsten oxide particle 1 and about 0.01 to about 5 parts by weight of the platinum particle 2 . By controlling their content in a weight ratio within the above range, the tungsten oxide particles 1 sufficiently generate electrons and holes by visible light, while the platinum particles 2 sufficiently prevent recombination of generated electrons and holes to activate photocatalytic activity. efficiency can be effectively improved. In addition, by adjusting their content to a weight ratio within the above range, the sulfur compound removal efficiency can be effectively improved even in the absence of light because the sulfur compound adsorption property of the composite particle 10 is not impaired.

When the content of the tungsten oxide particles (1) exceeds the content range, electrons and holes generated by visible light can easily recombine, and it is difficult to separate them, so that sufficient photocatalytic activity is not exhibited, and when the content is less than the content range Since the number of electrons transferred from the tungsten oxide particles 1 is not sufficiently secured, there is a risk that the photocatalytic activity may be reduced, and the photocatalytic performance may be reduced because the exposure area of the tungsten oxide particles 1 to light is reduced. .

The specific surface area of the tungsten oxide particles 1 may be about 50 m 2 /g to about 500 m 2 /g. By having a high level of specific surface area within the above range, the platinum particles 2 can be sufficiently supported by forming a porosity at an appropriate level while being effectively exposed to a light source such as visible light.

Hereinafter, a method for preparing a sulfur compound purification catalyst according to an embodiment of the present invention will be described in detail.

The method for preparing the sulfur compound purification catalyst proceeds by sequentially performing the following steps (a) to (c).

(a) A primary slurry solution is prepared by mixing tungsten oxide powder with a platinum precursor solution, and then the slurry solution is irradiated with light to conduct a primary photoreaction.

(b) centrifuging the primary slurry solution to collect the powder.

(c) Prepare a secondary slurry solution by mixing the powder of step (b) with water and an alcohol solution, and then irradiate with light to conduct a secondary photoreaction.

In step (a), the tungsten oxide powder is prepared by pulverizing it to a level of micro unit or less in order to maximize the reaction area.

As the platinum precursor compound for preparing the platinum precursor solution, a material that can be reduced to platinum by electrons excited by light irradiation may be used, and a salt compound dissolved in an aqueous solution may be used without limitation, specifically, PtCl ₂ , PtCl ₄ , PtBr ₂ , H ₂ PtCl ₆ , K ₂ (PtCl ₄ ), Pt(NH ₃ ) ₄ Cl ₂ , Pt(NH ₃ ) ₄ (OH) ₂ , Pt(NH ₃ ) ₄ (NO ₃ ) ₂ , Pt(NH ₃ ) ₂ (NO ₂ ) ₂ , H ₂ Pt(OH) ₆ , Na ₂ Pt(OH) ₆ , K ₂ Pt(OH) ₆ , and the like.

In one embodiment, the concentration of the platinum precursor solution may be adjusted as a relative content to the tungsten oxide powder such that the content of platinum is about 0.01 parts by weight to about 5 parts by weight based on 100 parts by weight of the tungsten oxide particles.

Platinum ions separated from the platinum precursor during the first photoreaction in step (a) are attached to the surface of the tungsten oxide particles, and the remaining platinum ions that are not attached are removed in step (b). It is understood that a reaction in which platinum ions attached to the surface of the tungsten oxide particles are reduced mainly occurs during the secondary photoreaction of step (c).

In one embodiment, the centrifugation of step (b) may separate the centrifugal force to about 5,000 G to about 15,000 G.

The finally obtained sulfur compound purification catalyst must be formed in such a way that the proportion of platinum particles completely reduced to zero oxidation number is higher. To this end, it is possible to obtain the above-described sulfur compound purification catalyst of the present invention by controlling various process conditions. Hereinafter, specific process conditions for synthesizing the sulfur compound purification catalyst of the present invention described above will be exemplarily described.

First, the ratio of the time for the first photoreaction (first photoreaction time) to the time for the second photoreaction (second photoreaction time) can be adjusted.

It is understood that the secondary photoreaction does not significantly affect the final formation rate of platinum particles having an oxidation number of 0 because the second photoreaction proceeds at a very fast rate. Good adhesion will affect the final rate of formation of 0-oxidized platinum particles.

Therefore, it is important to proceed the first photoreaction for a sufficient time so that the reaction can proceed sufficiently.

For example, the first photoreaction may be performed for 4 hours to 24 hours.

For example, the secondary photoreaction may be performed for 2 to 6 hours.

In one embodiment, the first photoreaction time is longer than the second photoreaction time, and specifically, the ratio of the first photoreaction time to the second photoreaction time may be 2:1 to 12:1.

In addition, when performing each photoreaction in steps (a) and (c) by light irradiation, it is important to sufficiently stir the first and second slurry solutions.

For example, an inert gas such as nitrogen may be injected into the first slurry solution or the second slurry solution to allow the slurry solution to be stirred while the photoreaction proceeds.

Depending on the injection flow rate and injection method and location of the inert gas, it may help the photoreaction to proceed well. For example, the flow rate of the inert gas injected into the first slurry solution or the second slurry solution may be 5 L/min to 30 L/min.

In one embodiment, nitrogen may be used as the inert gas. When the slurry solution is stirred using nitrogen gas, the stirring efficiency is excellent compared to mechanical stirring, and there is an advantage in that it is possible to obtain a secondary effect of removing oxygen in the first slurry solution or the second slurry solution.

In step (a), when preparing the first slurry solution, the concentration of the tungsten oxide powder may be 1 to 10 wt%.

In step (c), the ratio of alcohol in the water and alcohol mixed solution may be 1 to 30 wt% of the secondary slurry solution.

Illustratively, the viscosity of the first slurry solution or the second slurry solution may be about 5.0 cP to about 8.0 cP at 25°C. The viscosity of the first slurry solution or the second slurry solution may be measured using a Brookfield viscometer (Spindle No.: No. 61, speed: 200 rpm, measurement time: 30 seconds).

For example, in the first photoreaction, the intensity of light irradiation may be about 5,000 lux to about 100,000 lux, and in the second photoreaction, the intensity of light irradiation may be higher than the light irradiation intensity of the first photoreaction. . Specifically, the intensity of the secondary light irradiation may be 1 to 10 times, specifically 3 to 5 times higher than the intensity of the primary light irradiation.

After the secondary light irradiation, the catalyst recovery and drying steps are optionally performed by centrifugation or the like.

Hereinafter, Examples and Comparative Examples of the present invention will be described. The following examples are only examples of the present invention, and the present invention is not limited to the following examples.

(Example)

Example 1

A solution in which 5 wt% of tungsten oxide powder was dispersed in 95 wt% of water was prepared. An average particle diameter of 0.5 μm tungsten oxide powder dispersion solution was mixed with a 10 wt% aqueous solution of chloroplatinic acid (H ₂ PtCl ₆ ) to prepare a slurry solution such that the platinum content was 1 part by weight relative to 100 parts by weight of the tungsten oxide powder.

With respect to the slurry solution, the viscosity measured using a Brookfield viscometer (Spindle No.: No. 61, speed: 200 rpm, measurement time: 30 seconds) was 7.0 cP at 25°C.

Then, the slurry solution is introduced into the photoreactor, a gas generator is installed to be connected to the photoreactor, and then, during the subsequent primary and secondary light irradiation, nitrogen generated from the gas generator is converted into the slurry solution. The slurry solution was stirred by nitrogen by injecting it directly into the inside of the The purity of the input nitrogen was 98.00%, and the flow rate was 10 L/min.

Visible light energy of 400 nm to 700 nm was irradiated to the slurry solution in the photoreactor using a visible light irradiation device, and the first photoreaction was performed for 4 hours. The slurry was centrifuged to collect powder, and then dispersed in a solution in which water and methanol were mixed in a ratio of 95:5, and then, using the same irradiation device as in the first photoreaction, visible light energy was applied to the light. By irradiating the slurry solution in the reactor for 4 hours to perform a secondary photoreaction, platinum particles were supported on tungsten oxide particles to prepare a powder of a sulfur compound purification catalyst.

Comparative Example 1

A commercially available titanium oxide (TiO ₂ ) product (Ishihara, ST-01) was purchased and used.

Comparative Example 2

A commercially available titanium oxide (TiO ₂ ) product (Tayca, AMT-100) was purchased and used.

evaluation

Experimental Example 1

The performance evaluation of the sulfur compound purification catalyst prepared in Example 1 and Comparative Example 1-2 was performed by the gas bag evaluation described below.

A container containing 0.5 g of powder of the sulfur compound purification catalyst was placed in a gas bag, sealed, the remaining gas was drained, and 3 L of 1.6 ppm hydrogen sulfide gas was injected. The gas before injection and the gas 30 minutes after injection were analyzed for hydrogen sulfide concentration using a Gastec 4LT detector tube. The hydrogen sulfide removal rate was calculated as the percentage removed (ppm basis) with the initial ppm concentration being 100%. As such, the hydrogen sulfide removal performance of the sample was calculated and the evaluation results are shown in Table 1 below.

Experimental Example 2

The performance evaluation of the sulfur compound purification catalyst prepared in Example 1 and Comparative Example 1-2 was performed by the gas bag evaluation described below.

A container containing 0.5 g of powder of the sulfur compound purification catalyst was placed in a gas bag, sealed, the remaining gas was drained, and 3 L of 1.6 ppm hydrogen sulfide gas was injected. As for the illuminance condition, visible light having a wavelength of 400 nm to 700 nm was irradiated at 25,000 lux. The gas before injection and the gas 30 minutes after injection were analyzed for hydrogen sulfide concentration using a Gastec 4LT detector tube. The hydrogen sulfide removal rate was calculated as the percentage removed (ppm basis) with the initial ppm concentration being 100%. As such, the hydrogen sulfide removal performance of the sample was calculated and the evaluation results are shown in Table 1 below.

division Hydrogen sulfide removal rate (%) Experimental Example 1 Experimental Example 2 Illumination condition 0 lux 25,000 lux Example 1 48 77 Comparative Example 1 8 25 Comparative Example 2 0 15

In Table 1, in the case of Comparative Example 1 and Comparative Example 2, the hydrogen sulfide removal rate in the absence of light is very low. On the other hand, in Example 1, the removal rate of hydrogen sulfide is relatively high even in the absence of light, and in the condition in which there is light, Example 1 shows a significantly superior removal rate compared to Comparative Examples 1 and 2.

Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention defined in the following claims are also present. It belongs to the scope of the right of the invention.

1: Tungsten oxide particles
2: Platinum particles
10: composite particles

Claims (10)

platinum particles; It is a sulfur compound purification catalyst comprising composite particles comprising; tungsten oxide particles,
The tungsten oxide particles support the platinum particles,
After 0.5 g of the sulfur compound purification catalyst is put into a 3L container, sealed and degassed, a gas containing 1.6 ppm hydrogen sulfide is injected, and the hydrogen sulfide removal rate obtained by measuring the concentration 30 minutes after the hydrogen sulfide injection in the absence of light 40 to 99.9% of this
Sulfur Compound Purification Catalyst.
delete According to claim 1,
When the diameter of the composite particle is 1 μm or less
Sulfur Compound Purification Catalyst.
According to claim 1,
The platinum particles having a diameter of 1 nm to 10 nm
Sulfur Compound Purification Catalyst.
According to claim 1,
The content of the platinum particles relative to 100 parts by weight of the tungsten oxide particles is 0.01 parts by weight to 5 parts by weight
Sulfur Compound Purification Catalyst.
delete delete delete delete delete

Images