KR20190053496A - Platinum colloid-based platinum/vanadium/titania catalyst for removal of gaseous ammonia and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a platinum/vanadium/titania catalyst for removing gaseous ammonia and a method for manufacturing the same. When manufacturing a binary catalytic metal catalyst of platinum/vanadium, by manufacturing a final platinum/vanadium/titania catalyst by using platinum colloid as a platinum precursor substance after manufacturing a vanadium/titania catalyst, an overall manufacturing process can be simplified since a heat treatment process for a catalyst can be performed by a simple firing process without difficult and complicated separate reduction process, and also, it is possible to provide the catalyst in which a conversion ratio to low-concentration gaseous ammonia is greatly improved.

Description

TECHNICAL FIELD [0001] The present invention relates to a platinum colloid-based platinum / vanadium / titania catalyst for removing gaseous ammonia and a method for producing the same. BACKGROUND ART [0002]

The present invention relates to a catalyst used for selective catalytic oxidation (SCO) in which gaseous ammonia emitted from various ammonia sources is selectively converted to nitrogen, and a method for producing the catalyst. More specifically, the present invention relates to a catalyst for platinum- .

Recently accompanying the industrial and living environment changes as one of the main cause of air pollutants is a tendency that the discharge amount of nitrogen oxides such as _{NO, NO 2, N 2 O} , NH 3 increases. The concentration of ammonia (NH ₃ ) is classified as a malodorous substance by detecting odor at a concentration of 10 ppm or less. However, at a concentration of 100 ppm or more, mucous membrane abnormalities start to appear. Concentrations of more than 400 ppm, It is known to be harmful not only to the human body but also to plants and animals, which causes death and causes severe.

This ammonia is mainly generated in stationary pollutants such as thermal power plants, petroleum refineries, livestock facilities and industrial wastewater treatment facilities, and selective catalytic oxidation (SCO) The device is installed. Selective catalytic oxidation is a method of converting ammonia (NH ₃ ) to non-toxic nitrogen (N ₂ ) and water (H ₂ O) using a catalyst. The main reaction formula of the selective catalytic oxidation takes place in process of being converted into ammonia (NH ₃₎ and oxygen (O ₂₎ is reacted with a nitrogen (N ₂₎ and water (H ₂ O), part scheme is ammonia (NH ₃₎ (NO), nitrogen dioxide (NO ₂ ), and dinitrogen monoxide (N ₂ O) are produced by reacting oxygen (O ₂ ) with oxygen (O ₂ ). Since the nitrogen compounds generated according to these reaction formulas are substances that cause fine dusts and cause global warming, it is important to selectively treat ammonia with nontoxic nitrogen.

An example of a conventional catalyst for selectively removing ammonia and a method for producing the same is disclosed in Korean Patent Publication No. 10-2016-0095929. A catalyst according to Korean Patent Laid-Open Publication No. 10-2016-0095929 is a platinum / vanadium / titania catalyst. The vanadium precursor is supported on titania first and then calcined at 400 ° C. for 4 hours in an air atmosphere to obtain vanadium / titania Subsequently, a platinum precursor aqueous solution was supported on a vanadium / titania catalyst and calcined in an air atmosphere at a temperature of 400 ° C. for 4 hours. Finally, the catalyst was reduced at 600 ° C. for 1 hour under a hydrogen atmosphere to obtain platinum / vanadium / Titania catalyst. However, such a catalyst production method has to be accompanied by two additional firing steps and a final additional reduction step, which adds a complicated process, which complicates the process and equipment and increases the manufacturing cost.

Korean Patent Laid-Open No. 10-2017-0049811 discloses another example of a catalyst for removing ammonia, which is a silver / titania catalyst showing a conversion rate at 250 to 350 ° C. This silver / titania catalyst is used in a tubular furnace to produce 300 Lt; 0 > C for 2 hours in an air atmosphere, and then further reduced in a hydrogen atmosphere at 600 < 0 > C for 1 hour. However, the method of preparing a catalyst according to Korean Patent Laid-open No. 10-2017-0049811 also involves a further complicated reduction process like the Korean Patent Publication No. 10-2016-0095929.

Korean Patent Publication No. 10-2016-0095929 Korean Patent Publication No. 10-2017-0049811

The present invention provides a platinum / vanadium / titania catalyst which is produced without a complicated and complicated reduction process unlike the prior art, and which is excellent in conversion from low-concentration gaseous ammonia to nitrogen and water harmless to the human body, and a method for producing the same.

The present inventors have studied and developed a method for producing an ammonia-removing catalyst using a binary active metal of platinum and vanadium and a titania carrier without any complicated and complicated reduction process as in Korean Patent Laid-Open No. 10-2016-0095929 of the development of the conventional platinum-based catalyst manufacturing process, the reduction process, the via in the form of metal platinum is oxidized a zero-valent Pt ⁰ the metallic state on each of the dispersion medium in place of a manner that excellent activity as a platinum precursor dispersion to make a Pt ⁰ And a method of preparing the platinum colloid by dispersing it. On the other hand, when the platinum content is very low, it is difficult to separate and observe the oxidation state by XPS analysis. As a result, the mobility of oxygen species was selected as an important factor for improving the activity and yield of the catalyst, It has been found that the platinum / vanadium / titania catalyst can contain more oxygen species that affect the catalytic activity and yield because it is not subjected to a separate reduction process unlike the platinum / vanadium / titania catalyst that has undergone the conventional reduction process . In addition, ammonia adsorbed on the surface of vanadium and NO _x oxidized on the platinum surface must be converted to N ₂ by the I-SCR reaction. When platinum is first supported on a carrier and vanadium is carried later, is (overlapping) is possible, this transition to the nO _x from the surface of platinum is suppressed by reducing the nO _x is required for the reaction to the I-SCR conversion reduces the reaction of the NH ₃ conversion rate may not be smooth. Therefore, it is possible to expose more platinum to the surface of the catalyst by supporting vanadium first and then supporting platinum, thereby exhibiting an excellent conversion ratio. Ultimately, the platinum colloid-based platinum / vanadium / tinatia catalyst according to the present invention can provide both an oxidation state and an oxygen species advantageous merely by drying and calcining, so that it can exhibit excellent reaction activity against gaseous ammonia without a separate reduction process And the present invention has been accomplished. The gist of the present invention based on recognition and knowledge of the above-mentioned problems is as follows.

(1) A platinum / vanadium / titania catalyst is prepared by carrying a vanadium precursor on a titania carrier, drying and firing the vanadium / titania catalyst to prepare a vanadium / titania catalyst, carrying the platinum precursor on the vanadium / titania catalyst, followed by drying and firing, Wherein the precursor is a platinum colloid.

(2) The process for producing platinum / vanadium / titania for removing ammonia according to (1) above, wherein the oxidation of platinum in the platinum colloid is present as Pt ⁰ .

(3) The method for producing platinum / vanadium / titania for removing ammonia according to (1), wherein the vanadium precursor is 2 to 5 parts by weight based on 100 parts by weight of the titania carrier.

(4) The method for producing platinum / vanadium / titania according to the above (1), wherein the platinum precursor is 0.1 to 0.5 parts by weight based on 100 parts by weight of the vanadium / titania catalyst.

(5) The method for producing platinum / vanadium / titania for removing ammonia according to (1), wherein the calcining step is performed at a temperature of 300 ° C to 500 ° C for 3 to 5 hours.

(6) platinum and vanadium as active metals; And a titania carrier on which the active metal is supported, wherein the platinum is derived from platinum colloid as a precursor.

(7) The platinum / vanadium / titania catalyst for removing ammonia as described in (6) above, wherein the ratio of the _Oa species as the surface adsorbed oxygen species is 30% or more.

(8) The platinum / vanadium / titania catalyst for removal of ammonia according to (6), wherein the catalyst has a reaction activity at a temperature of 180 to 250 ° C.

(9) A platinum / vanadium / titania catalyst for removing ammonia produced by any one of the above-mentioned methods (1) to (6).

According to the present invention, the preparation of the vanadium / titania catalyst in the preparation of the binary catalytic metal catalyst of platinum / vanadium, followed by the preparation of the final platinum / vanadium / titania catalyst using the platinum colloid as the platinum precursor material, can only complicated simple firing step without the need for a separate circle reduction process to the whole not only the manufacturing process can be simplified as well, and 30% through the vanadium and process controls the ratio of the O _α species species, surface adsorbed oxygen is favorable to the I-SCR reaction The conversion rate to gaseous ammonia is greatly improved. For example, an I-SCR reaction is NH ₃ is converted to N ₂ by re-reacting with the NO _x in the NO _x conversion is converted so the unreacted NH ₃ on the catalyst reaction and the selectivity to N ₂ increase. That is, it is possible to provide a catalyst in which the yield of the gaseous ammonia, which is important in the selective oxidation reaction, is greatly improved to the harmless N ₂ gas.

1 is a graph showing H ₂ -TPR (H ₂ Temperature Programmed Reduction) analysis results for confirming oxygen species and hydrogen consumption amount in a catalyst prepared according to Production Example 1 and Comparative Production Example 2 of the present invention.
2 is a graph showing X-ray photoelectron spectroscopy (XPS) analysis results for investigating the surface oxidation state of the catalysts prepared according to Production Example 1, Production Example 4 and Production Example 5 of the present invention.

The catalyst according to the present invention is a platinum / vanadium / titania catalyst in the form of a platinum / vanadium / titania catalyst containing an active metal of platinum and vanadium, and in this case, vanadium and platinum in the order of titania carrier. And exhibits excellent reaction activity against low-concentration gaseous ammonia of 200 ppm or less. In addition, the catalyst according to the present invention is not accompanied by a reduction process unlike the prior art, and thus the catalyst and the preparation method thereof will be described in detail.

In the catalyst according to the present invention, the platinum is characterized in that it is derived using platinum colloid as its precursor. Means that the presence in the platinum colloid of fine Pt ⁰ oxidation of platinum and, in the case of using platinum as a platinum colloid precursors can be given a sufficient reaction activity even without the reduction process while the platinum content in a relatively small amount.

Specifically, the catalyst according to the present invention has a very low platinum content, and it is difficult to separate and observe its oxidation state by XPS analysis. Therefore, the oxygen species mobility is selected as an important factor for improving the catalyst activity and yield, And the ratio of O _alpha species as adsorbed oxygen species is controlled to 30% or more. When separating oxygen species of the O 1s of a platinum / vanadium / titania catalyst according to the present invention, the oxygen species in such a catalyst may be identified as O _α species, surface chemisorbed species and O _β species, lattice oxygen species, of which The surface chemisorption species O _α enhances the oxygen mobility and plays a role of facilitating the reaction with oxygen during the reaction using the catalyst. The surface ratio of the adsorbed oxygen species O _α is defined as the percentage of _α O / (O + _α O _β), it is important in this connection the content of vanadium. That is, since the addition of vanadium is in the form of a metal oxide, it has an oxygen species and increases oxygen species. However, as the content of vanadium increases, a large amount of vanadium is exposed on the surface of the catalyst. This suppresses the reaction of converting platinum NH ₃ to NO x Therefore, proper vanadium content is required in consideration of this.

The catalyst according to the present invention can be produced by (1) carrying a vanadium precursor on a titania carrier, followed by drying and firing to prepare a vanadium / titania catalyst, (2) carrying a platinum precursor on the vanadium / titania catalyst, Platinum / vanadium / titania catalyst is prepared by using platinum colloid in a state where Pt ⁰ in the oxidation state of Pt ⁰ is dispersed in a metal state in the dispersion medium as the platinum precursor. Also, with respect to the carrying order of vanadium and platinum, which are active metals, it is characterized in that vanadium is first carried and then platinum is carried. That is, ammonia adsorbed on the surface of vanadium and NO _x oxidized on the platinum surface must be converted to N ₂ by I-SCR reaction. When platinum is first supported on a carrier and vanadium is carried later, The conversion of NO _x from the platinum surface is inhibited and the conversion of NO _x required for the reaction to the I-SCR is reduced, so that the conversion of NH ₃ is reduced and the reaction may not be smooth. Therefore, The platinum support can expose more platinum on the catalyst surface, and thus can exhibit an excellent conversion rate.

Specifically, the preparation of the vanadium / titania catalyst as the intermediate product in the step (1) is carried out in the following order. First, a vanadium precursor is quantitatively determined in an amount of 2 to 5 parts by weight based on 100 parts by weight of a titania carrier to prepare an aqueous solution, and then a titania carrier is mixed to prepare a slurry. In this case, if the content of the vanadium precursor is less than 2 parts by weight based on 100 parts by weight of the titanium carrier, it is difficult to exhibit activity. If the content of the vanadium precursor is more than 5 parts by weight based on 100 parts by weight of the titania carrier, Is undesirably reduced. The vanadium precursor is not particularly limited, and for example, ammonium metavanadate (NH ₄ VO ₃ ) may be used.

Subsequently, the produced vanadium / titania slurry was thoroughly dried at a temperature of approximately 103 ° C. for 24 hours or more using a drier to completely remove water from the micropores, and then the sample was dried at a temperature of approximately 300 ° C. to 500 ° C. in an air atmosphere, Followed by calcining for about 5 hours to complete the production of the vanadium / titania catalyst as an intermediate product. With respect to the sintering process conditions, the bond between the active metal and the support does not exhibit weak activity when the temperature is 300 ° C. or less for 3 hours, and when the sintering is performed at 500 ° C. or more for 5 hours or more, the active sites are reduced due to aggregation of vanadium And thus it is not preferable.

Next, the preparation of the platinum / vanadium / titania catalyst as the final product in the step (2) is carried out in the following order. First, 0.1 to 0.5 parts by weight of platinum colloid based on 100 parts by weight of the vanadium / titania catalyst prepared in the step (1) is quantitatively determined and thoroughly mixed to prepare a slurry. In this case, if the amount of the platinum colloid is less than 0.1 part by weight based on 100 parts by weight of the vanadium / titania catalyst, it is difficult to exhibit sufficient activity by the platinum. If the content of the platinum colloid exceeds 0.5 part by weight based on 100 parts by weight of the vanadium / titania catalyst, And thus the catalyst production cost rises.

Subsequently, the prepared platinum / vanadium / titania slurry was thoroughly dried at a temperature of approximately 103 ° C for 24 hours or more using a drier in the same manner as in the above step (1) to completely remove moisture from the micropores, At 300 DEG C to 500 DEG C for 3 to 5 hours to complete the production of the vanadium / titania catalyst as a final product. With respect to the firing process conditions, the bond between the active metal and the support does not exhibit weak activity when the temperature is 300 ° C. or less for 3 hours, and when the firing is performed at 500 ° C. for 5 hours or more, the active spot is formed by the aggregation of vanadium and platinum The activity may be lowered, which is undesirable.

Meanwhile, the shape of the furnace used in the firing process in the above steps (1) and (2) is not particularly limited, and various types of furnaces such as a tube type, a convection type, and a grate type furnace can be used.

The prepared catalyst may be extruded in particle or monolith form together with a small amount of binder, or may be prepared in various forms such as slate, plate, and pellet, or may be made of metal or ceramic material A plate, a fiber, a filter, or a surface of a honeycomb structure.

Hereinafter, the present invention will be described more specifically based on preferred manufacturing examples and experimental examples of the present invention. However, it should be understood that the technical spirit of the present invention is not limited thereto, and various modifications may be made by those skilled in the art.

How to measure

The conversion of the gaseous ammonia was calculated according to the following equation (1). In addition, the nitrogen yield was measured, the concentration of NO generated gaseous ammonia to be injected is oxidized to a non-dispersive infrared gas analyzer (ZKJ-2, Fuji Electric Co. ), when the N ₂ O is Ultramat6 (Siemens Co.) (3M, 3La, 3L, GASTEC Co.), and the concentration of ammonia was measured by a detector tube (3M, 3La, 3L, GASTEC Co.). The yield to nitrogen was calculated according to the following formula (2).

Manufacturing example  One

First, ammonium metavanadate (NH ₄ VO ₃ ) was quantified to be 2 parts by weight based on 100 parts by weight of titania carrier as a vanadium precursor, and then dissolved in distilled water heated to 60 ° C or higher to prepare a vanadium precursor aqueous solution. Then, oxalic acid was added at a ratio of 1: 1 mole to increase the solubility of vanadium to prepare a vanadium precursor aqueous solution. The prepared vanadium precursor aqueous solution and titania were mixed to form a slurry, and then the water was removed by using a vacuum rotary evaporator. To completely remove water contained in the micropores, And dried. And then calcined in a tube furnace at a temperature of 400 DEG C for 4 hours in an air atmosphere to prepare a vanadium / titania catalyst. Subsequently, 0.1 part by weight of platinum colloid (Pt colloid) as a platinum precursor was added to 100 parts by weight of the vanadium / titania catalyst prepared above, and the mixture was mixed with a vanadium / titania catalyst to prepare a slurry. After thoroughly removing the moisture contained in the micropores, the micropores were sufficiently dried for 24 hours or more in a dryer at 103 ° C. Finally, a platinum colloid-type platinum / vanadium / titania catalyst was prepared by firing in a tube furnace at a temperature of 400 ° C. for 4 hours in an air atmosphere.

Manufacturing example  2

The procedure of Preparation Example 1 was repeated except that the content of platinum colloid in Production Example 1 was increased to 0.3 part by weight of 100 parts by weight of vanadium / titania catalyst.

Manufacturing example  3

The procedure of Preparation Example 1 was repeated except that the content of platinum colloid in Preparation Example 1 was increased to 0.5 parts by weight of 100 parts by weight of the vanadium / titania catalyst.

Manufacturing example  4

The procedure of Preparation Example 1 was repeated except that the content of vanadium in Production Example 1 was quantified to be 3 parts by weight based on 100 parts by weight of titania.

Manufacturing example  5

The procedure of Preparation Example 1 was repeated except that the content of vanadium in Production Example 1 was quantified to be 5 parts by weight based on 100 parts by weight of titania.

Comparative Manufacturing Example  One

A platinum / vanadium / titania catalyst was prepared in the same manner as in Production Example 1 except that platinum precursor was prepared by dissolving platinum hydroxide (Pt (OH) ₂ ) in a titania carrier in the process of adding platinum in Preparation Example 1 .

Comparative Manufacturing Example  2

A platinum / vanadium / titania catalyst was prepared in the same manner as in Comparative Preparation Example 1, except that in the heat treatment process of Comparative Preparation Example 1, the reduction process was further performed at 600 ° C for 1 hour.

The above-described Production Examples 1 to 5 and Comparative Production Examples 1 to 2 are summarized in the following [Table 1].

division Active ingredient content Active material precursor Titania
carrier Heat treatment condition Production Example 1 platinum 0.1 Platinum colloid TiO ₂ Plasticity
(400 [deg.] C for 4 hours) vanadium 2 Ammonium metavanadate Production Example 2 platinum 0.3 Platinum colloid TiO ₂ Plasticity
(400 [deg.] C for 4 hours) vanadium 2 Ammonium metavanadate Production Example 3 platinum 0.5 Platinum colloid TiO ₂ Plasticity
(400 [deg.] C for 4 hours) vanadium 2 Ammonium metavanadate Production Example 4 platinum 0.1 Platinum colloid TiO ₂ Plasticity
(400 [deg.] C for 4 hours) vanadium 3 Ammonium metavanadate Production Example 5 platinum 0.3 Platinum colloid TiO ₂ Plasticity
(400 [deg.] C for 4 hours) vanadium 5 Ammonium metavanadate Comparative Preparation Example 1 platinum 0.1 Platinum hydroxide TiO ₂ Plasticity
(400 [deg.] C for 4 hours) vanadium 2 Ammonium metavanadate Comparative Production Example 2 platinum 0.1 Platinum hydroxide TiO ₂ Reduction after firing
(400 [deg.] C for 4 hours)
(600 DEG C for 1 hour) vanadium 2 Ammonium metavanadate

Experimental Example  One

In order to evaluate the ammonia removal activity according to the type of the platinum precursor in the production of the ammonia-removing platinum / vanadium / titania catalyst according to the present invention, platinum / vanadium / titania catalyst of platinum colloid type and platinum / vanadium / The ammonia removal rate and the nitrogen yield were measured at 180 ~ 250 ° C, which is the reaction temperature range, after Comparative Preparation Example 1, which is a calcination catalyst, and Comparative Preparation Example 2, to which a reduction process after calcination was added. In this case, the concentration of ammonia 200 ppm / N _2, was a 10 vol% oxygen, water 6 vol%, the space velocity is 60,000 hr ^-.. It was measured by keeping a ^1. But did show a 95% conversion in Preparation Example 1 and the comparative temperature of 250 ℃ case of Preparation Example 2, the preparation of Example 1, NH ₃ conversion rate of not more than 10% in the catalyst of the same compared to prepare a heat-treating step Example 1 And the catalyst of Preparation Example 1 showed the best nitrogen conversion even at the lower temperature range. In the case of unreacted ammonia at the conversion rate of ammonia, the concentration of unreacted ammonia discharged without reaction was measured and calculated. Also, in the case of nitrogen yield, it was confirmed that the catalyst prepared in Preparation Example 1 exhibited the best nitrogen yield in a temperature range of 220 ° C or less. For reference, the calculation results of the ammonia removal rate and the nitrogen yield are shown in Table 2 below.

division Temperature (℃) Temperature (℃) 250 220 200 180 250 220 200 180 Ammonia Removal Rate (%) Nitrogen yield (%) Production Example 1 98.5 52.5 30 2 36.4 39.3 30 2 Comparative Preparation Example 1 8 0 0 0 8 0 0 0 Comparative Production Example 2 98.5 37 10 0 41.2 32.3 10 0

That is, it was confirmed from the results of Table 2 that when the platinum precursor, which is one of the active metals, is a platinum colloid in the case of ammonia removal characteristics, it shows excellent ammonia removal rate and nitrogen yield even only in the sintering process.

Experimental Example  2

A platinum / vanadium / titania catalyst of platinum colloid type was prepared by varying the content of platinum colloid to determine the ammonia removal rate and nitrogen yield. Ammonia conversion rate was 220 ° C or higher, and the conversion was 30% in the case of Production Example 1 at 200 ° C. In Production Examples 2 and 3 in which platinum colloid contents were 0.3 and 0.5, respectively Ammonia conversion ratio was 20%, respectively. Conversion rate tended to decrease. Nitrogen yield was the highest in the yield of Preparation Example 1 at all temperatures, except for the best yield when the platinum colloid content was 0.5 at 220 ° C. For reference, the calculation results of the ammonia removal rate and the nitrogen yield are shown in Table 3 below.

division Temperature (℃) Temperature (℃) 250 220 200 180 250 220 200 180 Ammonia Removal Rate (%) Nitrogen yield (%) Production Example 1 98.5 52.5 30 2 36.4 39.3 30 2 Production Example 2 96.5 49.5 20 0 32.3 33.1 20 0 Production Example 3 99.5 51 20 0 31.5 43.5 20 0

Experimental Example  3

Ammonia removal rate and nitrogen yield were measured in the same manner as in Experimental Example 1 with respect to Production Example 1, Production Example 4, and Production Example 5, which were prepared by varying the vanadium content of the platinum / vanadium / titania catalyst in platinum colloid form. Ammonia conversion rate was decreased as the content of vanadium increased. In detail, ammonia conversion was similar at 250 ° C, but at 220 ° C, Production Example 1, Production Example 4 and Production Example 5 gradually increased to 52.5, 45 and 10% And the ammonia conversion was 0% in Production Example 5 at 200 ° C. In the case of nitrogen yield, the conversion rate increased with increasing vanadium content at 250 ℃. From 220 ℃ or lower, ammonia conversion decreased and the yield decreased. For reference, the calculation results of the ammonia removal rate and the nitrogen yield are shown in Table 4 below.

division Temperature (℃) Temperature (℃) 250 220 200 180 250 220 200 180 Ammonia Removal Rate (%) Nitrogen yield (%) Production Example 1 98.5 52.5 30 2 36.4 39.3 30 2 Production Example 4 97 45 8 0 39.4 40.7 8 0 Production Example 5 95 10 0 0 64.8 9 0 0

Experimental Example  4

The H ₂ -TPR (H ₂ Temperature Programmed Reduction) analysis of the catalysts of Production Example 1 and Comparative Production Example 2, in which the conversion of ammonia was observed without additional reduction process, was performed according to the platinum precursor. The results are shown in FIG. The use of oxygen species in the catalyst allows the reaction to be carried out with nitrogen by the reaction of ammonia and oxygen. The amount of hydrogen consumed by injecting hydrogen gas while raising the temperature of the catalyst is measured, . That is, the hydrogen consumption area means the amount of oxygen in the catalyst.

Specifically, 2920 Autochem (Micromeritics) was used, and H2-TPR analysis was performed using a TCD (Thermal Conductivity Detector) as a detector for concentration measurement. The procedure of the analysis is as follows: 0.3 g of the catalyst pulverized to 100 μm or less is charged, and then 5 vol.% O ₂ / He of 50 cc / min is heated at a rate of 10 ° C./min for 30 minutes at 400 ° C., Respectively. Subsequently, the mixture was allowed to warm to room temperature, and then 5 vol.% H ₂ / Ar was added thereto for 1 hour to make the catalyst into a reducing atmosphere. Thereafter, the hydrogen consumption was measured up to 600 DEG C while the temperature was raised at 10 DEG C / min.

As a result of the H ₂ -TPR shown in FIG. 1, it was confirmed that Production Example 1 exhibited more hydrogen consumption of about 4.89 times as compared with Comparative Production Example 2, and thus had more oxygen content in the catalyst. Generally, when the amount of oxygen in the catalyst is large, it is advantageous for the oxidation reaction which can react with ammonia of the reaction gas. That is, it was confirmed that the platinum / vanadium / titania catalyst of the platinum colloid type had a higher ammonia conversion than that of the conventional platinum / vanadium / titania catalyst reduced by using the platinum hydroxide precursor.

Experimental Example  5

The O1s oxygen species of the platinum / vanadium / titania catalyst of platinum colloid type, Production Example 1, Production Example 4, and Production Example 5, which were prepared by varying the vanadium content, are shown in FIG. The oxygen species of the catalyst are divided into two types: surface chemisorption species which are O _α species and lattice oxygen species which is O _β species. Among them, the surface chemisorbed species promotes oxygen mobility, and the reaction with oxygen becomes more smooth. O ratio _α of the oxygen species O _α / indicate a ratio of (O _α + _β O), found to be 32.58% in Preparation Example 1, 31.26% in the preparation 4, in the case of Preparation Example 5 24.35%. I.e., it was the most common species of the O _α ratio in the case of Preparation Example 1 was ammonium conversion rate is highest with 32.58%, in the case of Preparation Example 5 was conversion of the low percentage of O _α was also low in most 24.35%. It was confirmed that the ratio of O _α should be 30% or more for ammonia conversion to reach 200 ° C. The surface ratios of O _alpha species of each catalyst are shown in Table 5 below.

Production Example 1 Production Example 4 Production Example 5 O? / (O? + O?) 32.58% 31.26% 24.35%

Claims (9)

A platinum / vanadium / titania catalyst is prepared by supporting a vanadium precursor on a titania carrier, drying and calcining the vanadium / titania catalyst to prepare a vanadium / titania catalyst, carrying the platinum precursor on the vanadium / titania catalyst, drying and firing the platinum precursor, Wherein the ammonia-removing platinum / vanadium / titania is colloidal.
The method for preparing platinum / vanadium / titania for removing ammonia according to claim 1, wherein the oxidation of platinum in the platinum colloid is present as Pt ⁰ .
The method of claim 1, wherein the vanadium precursor is 2 to 5 parts by weight based on 100 parts by weight of the titania support.
The method of claim 1, wherein the platinum precursor is 0.1 to 0.5 parts by weight based on 100 parts by weight of a vanadium / titania catalyst.
The method of claim 1, wherein the calcining step is performed at a temperature of 300 ° C to 500 ° C for 3 to 5 hours.
Platinum and vanadium as active metals; And a titania carrier on which the active metal is supported, wherein the platinum is derived from platinum colloid as a precursor.
The method of claim 6, wherein the surface adsorbed oxygen species O _α species ratio of 30% or more ammonia to remove platinum / vanadium / titania catalyst characterized in the catalyst.
7. The catalyst for removing ammonia according to claim 6, wherein the catalyst has a reaction activity at a temperature of 180 to 250 ° C.
A platinum / vanadium / titania catalyst for removal of ammonia produced by the method of any one of claims 1 to 6.

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