KR101616669B1 - Nitrogen oxide reduction catalyst and method of manufacturing the same - Google Patents

Abstract

The present invention relates to a nitrogen oxide reduction catalyst and a preparation method thereof. The nitrogen oxide reduction catalyst of the present invention comprises vanadium, a support metal, and a titania support body. The vanadium is supported to the titania support body before the support metal, or the vanadium and the support metal are supported to the titania support body together. The preparation method of the nitrogen oxide reduction catalyst comprises the steps of: preparing a vanadium precursor solution, a support metal precursor solution, and a titania support body; and supporting the vanadium in the vanadium precursor solution and the support metal in the support metal precursor solution to the titania support body. The nitrogen oxide reduction catalyst of the present invention has excellent activity as well as at low temperatures, and can reduce generation of N_2O.

Description

TECHNICAL FIELD [0001] The present invention relates to a nitrogen oxide reduction catalyst and a method for producing the same. BACKGROUND ART [0002]

The present invention relates to a nitrogen oxide reduction catalyst and a production method thereof.

Nitrogen oxides (NO _x ), a compound of nitrogen and oxygen, are produced by the oxidation of nitrogen (N ₂ ) present in the air at very high temperatures. There are many kinds of nitrogen oxides, but there are nitrogen monoxide (NO) and nitrogen dioxide (NO ₂ ) which are the main causes of pollution. Nitrogen oxides present in the atmosphere stimulate human eyes and respiratory tracts and can cause various diseases. In addition, nitrogen oxides cause acid rain, and they react with sunlight to generate ozone, which causes photochemical smog and can cause environmental pollution. For this reason, Europe and other countries are implementing policies to regulate nitrogen oxides in the atmosphere.

Nitrogen oxides are mainly generated in combustion facilities such as power plants, industrial boilers, and incinerators, and the amount of nitrogen oxides generated in vehicles such as automobiles and ships is also increasing. A post-treatment system that may be used in the source of nitrogen oxides may include an oxidation catalyst (DOC), a soot filter (DPF), and a selective catalytic reduction (SCR).

In particular, Selective Catalytic Reduction (SCR) is a selective reduction of nitrogen oxides using ammonia (NH ₃ ) as a reducing agent under an excessive oxygen condition. The selective catalytic reduction reactor is located at the end of the aftertreatment system and is prone to exposure to relatively low temperatures. The catalyst of the conventional selective catalytic reduction reaction has a high activity at a high temperature range of 300 to 400 ° C., but has a very low activity at a lower temperature. Further, when the SCR reaction is performed at a low temperature such as the post-treatment system, there is a problem that the conventional catalyst causes N ₂ O, which is a major greenhouse gas of global warming.

In order to solve the above problems, the present invention provides a nitrogen oxide reduction catalyst having excellent activity even at a low temperature.

The present invention provides a nitrogen oxide reduction catalyst capable of reducing the generation of N ₂ O.

The present invention provides a method for producing the nitrogen oxide reduction catalyst.

Other objects of the present invention will become apparent from the following detailed description and the accompanying drawings.

The nitrogen oxide reduction catalyst according to embodiments of the present invention includes vanadium, an auxiliary metal, and a titania support, wherein the vanadium is first supported on the titania support rather than the auxiliary metal, or the vanadium and the subsidy together with the titania Supported on a support.

The auxiliary metal may include at least one selected from tungsten and cerium.

The weight ratio of the titania support to the vanadium may be 1: 0.01-0.1.

The weight ratio of the titania support to the subsidy may be 1: 0.01-0.5.

The weight ratio of the auxiliary metal to the vanadium may be 3 to 20: 1.

The method for preparing a nitrogen oxide reduction catalyst according to embodiments of the present invention includes the steps of preparing a vanadium precursor solution, an auxiliary metal precursor solution, and a titania support, and a step of mixing the vanadium and the auxiliary metal precursor solution contained in the vanadium precursor solution And supporting the auxiliary metal contained on the titania support.

The weight ratio of the titania support and the vanadium is 1: 0.01-0.1, the auxiliary metal includes at least one selected from tungsten and cerium, and the weight ratio of the titania support and the subsidy may be 1: 0.01-0.5 .

The auxiliary metal may include at least one selected from tungsten and cerium, and the weight ratio of the titania support and the subsidy may be 1: 0.01-0.5.

The weight ratio of the auxiliary metal to the vanadium may be 3 to 20: 1.

The supporting step may include supporting the vanadium on the titania support, and supporting the auxiliary metal on the vanadium-supported titania support.

The step of supporting the vanadium on the titania support comprises: mixing the vanadium precursor solution with the titania support to form a first mixed solution; controlling the first mixed solution to a pressure of 100 to 300 mbar; 1 mixed solution is evaporated at a temperature of 40 to 160 ° C to form a vanadium / titania support on which the vanadium is supported by the titania; and drying the vanadium / titania support at a temperature of 80 to 200 ° C Lt; / RTI >

The step of supporting the auxiliary metal on the titania support may comprise: mixing the auxiliary metal precursor solution with the vanadium / titania support to form a second mixed solution; controlling the second mixed solution to a pressure of 100 to 300 mbar; Vanadium / titania support supported on the titania by evaporating the solvent contained in the second mixed solution at a temperature of 40 to 160 ° C to form an auxiliary metal / vanadium / titania support; Followed by drying at a temperature of 80 to 200 캜.

The nitrogen oxide reduction catalyst according to the embodiments of the present invention can reduce the nitrogen oxide at a high efficiency even at a low temperature. The nitrogen oxide reduction catalyst can reduce N ₂ O generation. The nitrogen oxide reduction catalyst can be mass-produced in a simple process and at a low cost.

1 shows a method for producing a nitrogen oxide reduction catalyst according to embodiments of the present invention.
Figs. 2 to 4 show the NO _x conversion of the nitrogen oxide reduction catalyst according to an experimental example of the present invention.
5 to 7 show the amount of N ₂ O generated in the nitrogen oxide reduction catalyst according to an experimental example of the present invention.
8 shows the conversion of NO _x and the amount of N ₂ O generated in the tungsten-supported nitrogen oxide reduction catalyst according to an experimental example.
9 shows the NO _x conversion and the amount of N ₂ O generated in the cerium-supported nitrogen oxide reduction catalyst according to one experimental example.
FIG. 10 shows the conversion of NO _x by the supported ratio of the nitrogen oxide reduction catalyst according to one experimental example of the present invention.
FIG. 11 shows the amount of N ₂ O generated per supported ratio of the nitrogen oxide reduction catalyst according to one experimental example of the present invention.
FIG. 12 shows the conversion ratio of NO _x by the supported ratio of the nitrogen oxide reduction catalyst according to one experimental example of the present invention.
13 shows the amount of N ₂ O generated by the supported ratio of the nitrogen oxide reduction catalyst according to an experimental example of the present invention.
FIG. 14 shows the conversion ratio of NO _x by the supported ratio of the nitrogen oxide reduction catalyst according to one experimental example of the present invention.
FIG. 15 shows the amount of N ₂ O generated per supported ratio of the nitrogen oxide reduction catalyst according to an experimental example of the present invention. FIG.

Hereinafter, the present invention will be described in detail with reference to examples. The objects, features and advantages of the present invention will be easily understood by the following embodiments. The present invention is not limited to the embodiments described herein, but may be embodied in other forms. The embodiments disclosed herein are provided so that the disclosure may be thorough and complete, and that those skilled in the art will be able to convey the spirit of the invention to those skilled in the art. Therefore, the present invention should not be limited by the following examples.

In this specification, the name of the catalyst may be denoted according to the order in which the metal is supported on the support. For example, when A metal and B metal are successively deposited on S, they can be represented by B / A / S or B / A / S catalysts. S or AB / S, or may be labeled BA / S catalyst or AB / S catalyst. Further, the intermediate product in which A is supported on S may be referred to as an A / S support before forming the catalyst, and the intermediate product in which A metal and B metal are successively supported on S B / A / S < / RTI > support.

The Selective Catalytic Reduction (SCR) reaction (hereinafter referred to as SCR reaction) is a selective reduction reaction of NO _x by using ammonia (NH ₃ ) as a reducing agent under oxygen conditions. Can exist.

4NO + 4NH ₃ + O ₂ ? 4N ₂ + 6H ₂ O

_{2NO 2 + 4NH 3 + O 2} → 3N 2 + 6H 2 O

_{NO + NO 2 + 2NH 3 →} 2N 2 + 3H 2 O

Although the nitrogen oxide reduction catalyst according to the embodiments of the present invention has been described as capable of selectively reducing the nitrogen oxide, it can be used to reduce other substances depending on reaction conditions, reactants, and the like.

The nitrogen oxide reduction catalyst according to embodiments of the present invention includes vanadium (V), an auxiliary metal, and a Titania support.

The Titania support may be titanium dioxide (TiO ₂ ).

The vanadium may be supported on the titania support in the form of V ₂ O ₃ , V ₂ O ₄ , and / or V ₂ O ₅ . In order to carry the vanadium on the titania support, the vanadium precursor solution may be used. The vanadium precursor solution may include ammonium metavanadate and oxalic acid.

The auxiliary metal may be at least one selected from cerium, Ce, tungsten, W, Zinc, Zn, and manganese. Preferably, it may be at least one selected from the group consisting of cerium and tungsten. The cerium and / or the tungsten-supported nitrogen oxide reduction catalyst may be more active than the zinc oxide and / or the manganese-supported nitrogen oxide reduction catalyst. However, the nitrogen oxide reduction catalyst supporting the zinc and / or manganese may exhibit excellent activity depending on the reaction conditions, the composition of the catalyst, and the order of carrying the catalyst. If two or more subsidies are loaded, the SCR reaction may be more likely to occur due to synergy.

In order to support the auxiliary metal on the titania support, the precursor solution in the subsystem may be used. For example, if the subsidy is tungsten, the precursor solution of tungsten may include ammonium tungstate, and if the subsidy is cerium, the precursor solution of cerium may be cerium (Cerium III) nitrate hexahydrate).

The weight ratio of the titania support to the vanadium may be 1: 0.01 to 1. Preferably, the weight ratio of the titania support to the vanadium may be 1: 0.01 to 0.1. More preferably, the weight ratio of the titania support to the vanadium may range from 1: 0.01 to 0.03. The higher the weight ratio of vanadium is, the weaker the effect of the subsidy can be. The weight ratio between the titania support and the vanadium can be adjusted depending on the target substance to be reduced and the environmental condition. For example, the weight ratio of the titania support to the vanadium may be different between a low temperature condition of about 200 ° C and a high temperature condition of about 400 ° C.

The weight ratio of the titania support to the subsidy may be 1: 0.01 to 1. Preferably, the weight ratio of the titania support to the subsidy may be 1: 0.01-0.5. More preferably, the weight ratio of the titania support to the subsidy may be 1: 0.09 to 0.15. As the weight ratio of the subsidy increases, the effect due to the type of the subsidy can be increased. The weight ratio between the titania support and the subsidy can be adjusted according to the target substance to be reduced and the environmental condition. For example, the weight ratio of the titania support to the subsidy may be different when the temperature is in a low temperature condition of about 200 ° C or more and in a high temperature condition of about 400 ° C or so.

If there are two or more subsidies, the ratio between the auxiliary metals can be adjusted. When the subsidy is the tungsten and the cerium, the weight ratio of the tungsten and the cerium may be 1: 0.01 to 100.

The weight ratio of the auxiliary metal to the vanadium may be 3 to 20: 1. Preferably, the weight ratio of the auxiliary metal to the vanadium may be 9 to 15: 1. The weight ratio of the auxiliary metal to the vanadium may be adjusted depending on the target material to be reduced and the environmental condition. For example, the weight ratio of the auxiliary metal to the vanadium may be different between a low-temperature condition of about 200 ° C and a high-temperature condition of about 400 ° C.

1 is a method for producing a nitrogen oxide reduction catalyst according to embodiments of the present invention.

Referring to FIG. 1, the nitrogen oxide reduction catalyst manufacturing method includes a vanadium precursor solution, an auxiliary metal precursor solution, and a titania support preparation step (S10) and a step (S20) of supporting vanadium and an auxiliary metal on a titania support.

The vanadium precursor solution, the auxiliary metal precursor solution, and the titania support are prepared (S10). The vanadium precursor solution may include ammonium metavanadate and oxalic acid solution. For example, the vanadium precursor solution may be prepared by adding the ammonium metavanadate to the third purified water, and then mixing the oxalic acid solution with 0.5M of the solution.

The auxiliary metal precursor solution may comprise at least one precursor selected from a tungsten precursor, a cerium precursor, a zinc precursor, and a manganese precursor. For example, when the subsidy is tungsten, the precursor of tungsten may include the ammonium tungstate. If the subsidy is cerium, the precursor of cerium may comprise the cerium (III) nitrate hexahydrate.

The vanadium and the subsidy are supported on the titania support (S20). The vanadium and the subsidy may be carried on the titania support, or the vanadium may be supported on the titania support before the auxiliary metal.

For example, when the vanadium is supported on the titania support before the auxiliary metal, the vanadium precursor solution and the titania support are mixed to form a first mixed solution. The pressure of the first mixed solution is adjusted. The pressure can be adjusted to 100 to 300 mbar. The solvent contained in the first mixed solution may be evaporated to form a vanadium / titania support. The solvent may be evaporated at a temperature of 40 to 160 ° C. The vanadium / titania support may be dried at a temperature of 80 to 200 ° C. The vanadium / titania support and the auxiliary metal precursor solution may be mixed to form a second mixed solution. The second mixed solution can be adjusted to a pressure of 100 to 300 mbar. The solvent contained in the second mixed solution may be evaporated at a temperature of 40 to 160 ° C to form an auxiliary metal / vanadium / titania support. The auxiliary metal / vanadium / titania support may be dried at a temperature of 80 to 200 ° C. As a result, an auxiliary metal / vanadium / titania catalyst which is a nitrogen oxide reduction catalyst according to embodiments of the present invention can be formed. If there are two or more subsidy entities, the above steps may be repeated in the order to be carried.

In another example, when the vanadium and the auxiliary metal are supported together on the titania support, the vanadium precursor solution and the auxiliary metal precursor solution are mixed to form a third mixed solution. The third mixed solution and the titania support are mixed to form a fourth mixed solution. And the pressure of the fourth mixed solution is adjusted. The pressure can be adjusted to 100 to 300 mbar. The solvent contained in the fourth mixed solution may be evaporated at a temperature of 40 to 160 ° C to form an auxiliary metal-vanadium / titania support. The auxiliary metal-vanadium / titania support may be dried at a temperature of 80 to 200 ° C. As a result, an auxiliary metal-vanadium / titania catalyst which is a nitrogen oxide reduction catalyst according to embodiments of the present invention can be formed.

The weight ratio of the titania support to the vanadium may be 1: 0.01 to 1. Preferably, the weight ratio of the titania support to the vanadium may be 1: 0.01 to 0.1. More preferably, the weight ratio of the titania support to the vanadium may range from 1: 0.01 to 0.03. The higher the weight ratio of vanadium is, the weaker the effect of the subsidy can be. The weight ratio between the titania support and the vanadium can be adjusted depending on the target substance to be reduced and the environmental condition. For example, the weight ratio of the titania support to the vanadium may be different between a low temperature condition of about 200 ° C and a high temperature condition of about 400 ° C.

The weight ratio of the titania support to the subsidy may be 1: 0.01 to 1. Preferably, the weight ratio of the titania support to the subsidy may be 1: 0.01-0.5. More preferably, the weight ratio of the titania support to the subsidy may be 1: 0.09 to 0.15. As the weight ratio of the subsidy increases, the effect due to the type of the subsidy can be increased.

If the subsidy content is more than two, the weight ratio between the auxiliary metals can be adjusted. When the subsidy is the tungsten and the cerium, the weight ratio of the tungsten and the cerium may be 1: 0.01 to 100.

The weight ratio of the subsidy can be adjusted according to the target substance to be reduced and environmental conditions. For example, the weight ratio in the subsidy may be different when the temperature is low at about 200 ° C and when the temperature is high at about 400 ° C.

The weight ratio of the auxiliary metal to the vanadium may be 3 to 20: 1. Preferably, the weight ratio of the auxiliary metal to the vanadium may be 9 to 15: 1 to 5. The weight ratio between the auxiliary metal and the vanadium may be adjusted depending on the target material to be reduced and the environmental condition. For example, the weight ratio of the auxiliary metal to the vanadium may be different between a low-temperature condition of about 200 ° C and a high-temperature condition of about 400 ° C.

The nitrogen oxide reduction catalyst may be calcined at 300 to 800 ° C. Preferably, it can be fired at 400 DEG C for 4 to 10 hours. The firing can improve the stability of the nitrogen oxide reduction catalyst.

The nitrogen oxide reduction catalyst according to embodiments of the present invention may be formed to have a diameter of 100-1000 mu m after being fired. In one embodiment, the nitrogen oxide reduction catalyst may be formed to a diameter of 300-500 탆.

The nitrogen oxide reduction catalyst according to embodiments of the present invention may be manufactured in a pellet, monolith, and / or particle form.

[Experimental Example 1]

The SCR reactivity of the nitrogen oxide reduction catalyst including the vanadium, the auxiliary metal, and the titania support according to the production conditions can be determined through the present experimental example.

Ammonium metavanadate is dissolved in oxalic acid solution to form the vanadium precursor. In this experimental example, the vanadium precursor solution was prepared by adding 1.345 g of ammonium metavanadate to 100 ml of tertiary purified water, and then adding and dissolving 70 ml of 0.5 M oxalic acid solution.

A precursor in the subsidy is prepared. The auxiliary metal may be at least one selected from the group consisting of cerium, zinc, and manganese. In this experimental example, ammonium tungstate was used as the precursor of tungsten, and cerium (III) nitrate hexahydrate was used as the precursor of cerium in the tertiary purified water.

TiO ₂ powder in the anatase phase was used as the titania support.

The order of carrying the vanadium and / or the auxiliary metal was set in the following three groups.

A catalyst: auxiliary metal / vanadium / titania

B catalyst: vanadium / auxiliary metal / titania

C catalyst: auxiliary metal - vanadium / titania

In this experiment, the catalyst A was prepared by first supporting the vanadium on the titania support, and then supporting the auxiliary metal. The B catalyst is a catalyst prepared by first supporting the auxiliary metal on the titania support, and then supporting the vanadium. The C catalyst is a catalyst prepared by mixing the vanadium and the auxiliary metal and supporting the vanadium and the auxiliary metal together on the titania support.

In this experiment, the catalyst A was prepared in the following manner. The vanadium precursor solution and the titania support were mixed in a rotary evaporator to form a first mixed solution. The pressure of the first mixed solution was adjusted to 200 mbar. The solvent contained in the first mixed solution was evaporated at a temperature of 80 ° C to form a vanadium / titania support. The vanadium / titania support was dried at a temperature of 105 DEG C for 12 hours. The vanadium / titania support and the auxiliary metal precursor solution are mixed to form a second mixed solution. The pressure of the second mixed solution was adjusted to 200 mbar. The solvent contained in the second mixed solution was evaporated at a temperature of 80 ° C to form an auxiliary metal / vanadium / titania support. The auxiliary metal / vanadium / titania support was dried at a temperature of 105 DEG C for 12 hours. Whereby the catalyst A was formed.

In this experiment, the catalyst B was prepared in the following manner. The auxiliary metal precursor solution and the titania support were mixed in a rotary evaporator to form a fifth mixed solution. The pressure of the fifth mixed solution was adjusted to 200 mbar. The solvent contained in the fifth mixed solution was evaporated at 80 ° C. to form an auxiliary metal / titania support. The auxiliary metal / titania support was dried at a temperature of 105 DEG C for 12 hours. The auxiliary metal / titania support and the vanadium precursor solution were mixed to form a sixth mixed solution. The pressure of the sixth mixed solution was adjusted to 200 mbar. The solvent contained in the sixth mixed solution was evaporated at a temperature of 80 ° C to form a vanadium / auxiliary metal / titania support. The vanadium / auxiliary metal / titania support was dried at a temperature of 105 ° C for 12 hours. Whereby the B catalyst was formed.

In this experiment, the catalyst C was prepared in the following manner. The vanadium precursor solution and the auxiliary metal precursor solution were mixed in a rotary evaporator to form a third mixed solution. The third mixed solution and the titania support were mixed to form a fourth mixed solution. The pressure of the fourth mixed solution was adjusted to 200 mbar. The solvent contained in the fourth mixed solution was evaporated at a temperature of 80 ° C to form an auxiliary metal-vanadium / titania support. The auxiliary metal-vanadium / titania support was dried at a temperature of 105 ° C for 12 hours. Through this, the C catalyst was formed.

In this experiment, the catalysts A to C were calcined at 400 DEG C for 4 hours. The temperature and / or the time of the firing may vary depending on experimental conditions, the amount of the support, and / or the amount of production. The firing temperature may be 300 to 800 ° C.

The SCR reactivity test of the catalyst A to the catalyst C according to this Experimental Example was performed. The SCR reactivity was compared through nitrogen oxide (NO _x ) conversion (Conversion,%) and N ₂ O emissions. In this experimental example, the above SCR reactivity test conditions are as follows.

- 500 ppm NO, 500 ppm NH ₃ , 2% O ₂ , N ₂ balance

- Space velocity (SV): 40,000h ^-1

- Temperature: 150 ~ 400 ℃

- Temperature change condition: The temperature was increased at a rate of 5 ° C / min. After a stabilization time of 40 minutes at 50 ° C intervals, the amount of NO, NO ₂ , and N ₂ O was measured

Figs. 2 to 4 show the NO _x conversion of the nitrogen oxide reduction catalyst according to an experimental example of the present invention.

Referring to FIG. 2, the NO _x conversion of the catalyst A can be determined. In the A catalyst, when the subsidy is tungsten or cerium, it exhibits the highest NO _x conversion. Particularly, in the vicinity of 200 캜 which is a low temperature region, the tungsten or the cerium-supported catalyst A exhibits the NO _x conversion rate as high as about 80%. In the case of the catalyst A carrying the zinc and the manganese, the conversion was 50% or less.

Referring to FIG. 3, the NO _x conversion ratio of the catalyst B can be determined. The B catalyst supported with tungsten, cerium, or zinc exhibits a similar NO _x conversion rate in the temperature range of 150 to 400 ° C. At around 200 ° C, which is a low temperature region, the NO _x conversion was 70% or less. The B catalyst on which tungsten or cerium was supported exhibited a lower NO _x conversion than the A catalyst.

Referring to FIG. 4, the NO _x conversion of the C catalyst can be determined. At a low temperature 200 ℃, the catalyst C is shown the NO _X conversion rate similar to that of the A catalyst. Further, in the case of the C catalyst carrying the zinc at a low temperature of 200 캜, the NO _x conversion was higher than that of the A catalyst.

From the above results, it can be seen that the catalyst A or the catalyst C supported with tungsten or cerium exhibits excellent NO _x conversion.

5 to 7 show the amount of N ₂ O generated in the nitrogen oxide reduction catalyst according to an experimental example of the present invention.

Referring to FIG. 5, the amount of N ₂ O generated in the catalyst A can be determined. The amount of N ₂ O generated in the A catalyst starts to gradually increase from 250 ° C., and is about 10 to 30 ppm at 350 ° C.

Referring to FIG. 6, the amount of N ₂ O generated in the catalyst B can be determined. The amount of N ₂ O generated in the B catalyst begins to gradually increase from 250 ° C., and represents an amount of about 20 to 50 ppm at 350 ° C.

Referring to FIG. 7, the N ₂ O generation amount of the C catalyst can be known. The N ₂ O generation amount of the C catalyst starts to gradually increase from 250 ° C., and shows an amount of about 20 to 40 ppm at 350 ° C.

From the above results, it can be seen that the amount of N ₂ O is relatively low in the A catalyst or the C catalyst.

8 shows the conversion of NO _x and the amount of N ₂ O generated in the tungsten-supported nitrogen oxide reduction catalyst according to an experimental example. Referring to FIG. 8, the catalyst carrying the vanadium first and supporting the tungsten exhibited a high NO _x conversion and a low amount of N ₂ O. When the tungsten and vanadium were carried together, a high NO _x conversion was obtained, and the amount of N ₂ O was also low.

9 shows the NO _x conversion and the amount of N ₂ O generated in the cerium-supported nitrogen oxide reduction catalyst according to one experimental example. Referring to FIG. 9, the catalyst carrying the vanadium first and supporting the cerium exhibited a high NO _x conversion and a low amount of N ₂ O. When the cerium and vanadium were carried together, a high NO _x conversion was obtained, and the amount of N ₂ O was also low.

From the above results, it can be seen that when the tungsten or cerium is supported by the auxiliary metal, when the vanadium is first supported or when the vanadium and the auxiliary metal are supported together, the excellent SCR reactivity is exhibited.

[Experimental Example 2]

The difference in SCR reactivity according to the loading amount of tungsten and / or cerium can be determined through this experimental example. The difference in the SCR reactivity according to the loading ratio of the tungsten and / or the cerium and the vanadium can be seen.

The nitrogen oxide reduction catalyst according to this experimental example was prepared by the following method.

The ammonium metavanadate is dissolved in the oxalic acid solution to form a precursor of the vanadium. In this experimental example, the vanadium precursor solution was prepared by adding 1.345 g of ammonium metavanadate to 100 ml of tertiary purified water, and then adding and dissolving 70 ml of 0.5 M oxalic acid solution.

In this Experimental Example, the tungsten precursor was the ammonium tungstate, and the cerium precursor was the cerium (III) nitrate hexahydrate, dissolved in the tertiary purified water.

TiO ₂ powder of the anatase phase was used as the titania.

The vanadium precursor solution and the titania support were put into a rotary evaporator to form the first mixed solution. The first mixed solution was adjusted to a pressure of 200 mbar. The solvent contained in the first mixed solution was evaporated at 80 ° C to form a vanadium / titania support. The vanadium / titania support was dried at 105 DEG C for 12 hours. Then, the auxiliary metal precursor solution and the vanadium / titania support were mixed in the rotary concentrator to form a second mixed solution. The second mixed solution was adjusted to a pressure of 200 mbar. The solvent contained in the second mixed solution was evaporated at 80 캜 to form an auxiliary metal / vanadium / titania support. The auxiliary metal / vanadium / titania support was dried at 105 DEG C for 12 hours. The auxiliary metal / vanadium / titania support was calcined at 400 ° C. for 4 hours to form the nitrogen oxide reduction catalyst according to this experimental example.

In the present Experimental Example, in the case of the tungsten / vanadium / titania catalyst in which the tungsten and vanadium were supported in a weight ratio of 9: 3, it was expressed as W / V / Ti (9: 3).

In the case of the cerium / vanadium / titania catalyst supported at the weight ratio of 9: 3 of cerium and vanadium, it was expressed as Ce / V / Ti (9: 3).

Ce / V / Ti (9: 9) in the case of the tungsten / cerium / vanadium / titania catalyst in which the tungsten, cerium and vanadium are supported in a weight ratio of 9: 9: : 3).

Tungsten / vanadium / titania catalyst in which the tungsten, cerium, and vanadium are supported in a weight ratio of 9: 9: 3, and Ce / W / V / Ti (9: : 3).

Under the following conditions, the SCR reactivity test of the nitrogen oxide reduction catalyst according to this Experimental Example was carried out.

- 500 ppm NO, 500 ppm NH ₃ , 2% O ₂ , N ₂ balance

- Space velocity (SV): 40,000h ^-1

- Temperature: 150 ~ 400 ℃

- Temperature change condition: The temperature was increased at a rate of 5 ° C / min. After a stabilization time of 40 minutes at 50 ° C intervals, the amount of NO, NO ₂ , and N ₂ O was measured

FIG. 10 shows the conversion of NO _x by the supported ratio of the nitrogen oxide reduction catalyst according to one experimental example of the present invention. Referring to Figure 10, when the titania support of 100 parts by weight, part of the vanadium is 3 parts by weight, and it can be seen that NO _X conversion rate of the trick-grant denied 9 parts by weight of the nitrogen oxide reduction catalyst. In Figure 10, referring to 200 ℃ low temperature range, W / V / Ti (9 : 3): NO X conversion rate is a solid catalyst into NO _X conversion rate is highest, and the catalyst and then Ce / V / Ti (3 9 ) .

FIG. 11 shows the amount of N ₂ O generated per supported ratio of the nitrogen oxide reduction catalyst according to one experimental example of the present invention. Referring to FIG. 11, when the titania support is 100 parts by weight, the amount of N ₂ O in the nitrogen oxide reduction catalyst is 3 parts by weight of the vanadium and 9 parts by weight of the support. In the case of the Ce / V / Ti (9: 3) catalyst, the amount of N ₂ O is the lowest in both the low temperature region at 200 ° C and the high temperature region at 400 ° C. It can be seen that the amount of N ₂ O generated in the catalyst containing cerium (Ce) such as Ce / W / V / Ti (9: 9: 3)

Referring to FIG. 10 and FIG. 11, the N ₂ O generation amount was compared with the NO _X conversion rate, and the SCR reactivity was examined. The nitrogen oxide reduction catalyst Ce / V / Ti (9: ), Ce / W / V / Ti (9: 9: 3), and W / Ce / V / Ti (9: 9: 3) catalyst exhibit comparatively excellent SCR reactivity.

FIG. 12 shows the conversion ratio of NO _x by the supported ratio of the nitrogen oxide reduction catalyst according to one experimental example of the present invention. Referring to Figure 12, when the titania support of 100 parts by weight, the vanadium is 1 part by weight, and it can be seen that NO _X conversion rate of the trick-grant denied 9 parts by weight of the nitrogen oxide reduction catalyst. The NO _x conversion of the Ce / V / Ti (9: 1) catalyst was the highest. The NO _x conversion of the W / V / Ti (9: 1), W / Ce / V / Ti (9: 9: 1) and Ce / W / V / Ti Area.

13 shows the amount of N ₂ O generated by the supported ratio of the nitrogen oxide reduction catalyst according to an experimental example of the present invention. Referring to FIG. 13, when the titania support is 100 parts by weight, the amount of generated N ₂ O of the nitrogen oxide reduction catalyst, which is 1 part by weight of vanadium and 9 parts by weight of the subsidium, can be known. W / V / Ti (9: 9: 1), Ce / V / Ti (9: 1), W / 1) the catalyst both showed a lower N ₂ O emissions.

FIG. 14 shows the conversion ratio of NO _x by the supported ratio of the nitrogen oxide reduction catalyst according to an experimental example of the present invention. Referring to Figure 14, wherein the titania support, it can be seen that NO _X conversion rate of 100 parts by weight when the vanadium is 1 part by weight and the grant hollow 15 parts by weight, the NOx reducing catalyst. W / Ce / V / Ti (15: 15: 1) exhibited high NO _x conversion in both the low temperature region of 200 ° C and the high temperature region of 400 ° C. Next, the NO _x conversion rate was increased in the order of Ce / W / V / Ti (15: 15: 1), Ce / V / Ti (15: 1) and W / V / Ti appear.

FIG. 15 shows the amount of N ₂ O generated per supported ratio of the nitrogen oxide reduction catalyst according to one experimental example of the present invention. Referring to FIG. 15, when the titania support is 100 parts by weight, the amount of vanadium is 1 part by weight and the amount of N ₂ O in the nitrogen oxide reduction catalyst is 15 parts by weight. W / V / Ti 15: 1, Ce / V / Ti 15: 1, W / Ce / V / Ti 15: 1) the catalyst both showed a lower N ₂ O emissions.

14 and 15, when the weight ratio of the auxiliary metal to the vanadium is 15: 1, the synergistic effect of the two subsidies is shown, and Ce / W / V / Ti and W / Ce / V / Ti It can be seen that the above-mentioned SCR reactivity can be relatively good.

Hereinafter, specific embodiments of the present invention have been described. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

Claims (10)

delete delete delete delete delete Preparing a vanadium precursor solution, an auxiliary metal precursor solution, and a titania support;
Supporting the vanadium contained in the vanadium precursor solution on the titania support; And
And supporting the auxiliary metal contained in the auxiliary metal precursor solution on the vanadium-supported titania support,
The step of supporting the vanadium on the titania support comprises:
Mixing the vanadium precursor solution with the titania support to form a first mixed solution;
Adjusting the pressure of the first mixed solution to 100 to 300 mbar;
Evaporating the solvent contained in the first mixed solution at 40 to 160 ° C to form a vanadium / titania support on the titania; And
And drying the vanadium / titania support at a temperature of 80 to 200 DEG C,
The step of supporting the auxiliary metal on the titania support comprises:
Mixing the auxiliary metal precursor solution with the titania support to form a second mixed solution;
Adjusting the second mixed solution to a pressure of 100 to 300 mbar;
Evaporating the solvent contained in the second mixed solution at a temperature of 40 to 160 ° C to form an auxiliary metal / vanadium / titania support on the titania; And
And drying the auxiliary metal / vanadium / titania support at a temperature of 80 to 200 ° C,
Wherein the auxiliary metal comprises at least one selected from tungsten and cerium. The method according to claim 6,
The weight ratio of the titania support to the vanadium is 1: 0.01 to 0.1,
Wherein the weight ratio of the titania support to the subsidy is 1: 0.01 to 0.5. The method according to claim 6,
Wherein the weight ratio of the auxiliary metal to the vanadium is 3 to 20: 1.
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