KR20090040080A - Zeolite-catalysts for the decomposition of nitrous oxide and nitrogen oxide and preparing method thereof - Google Patents

Abstract

A zeolite catalyst for decomposing nitrous oxide and nitrogen oxides and a manufacturing method thereof are provided to offer high activity in a decomposition of N2o and to offer hydrothermal stability. A zeolite catalyst for decomposing nitrous oxide and/or nitrogen oxides is formulated zeolite together with transition metals selected from Fe, Co, and Cu. The zeolite has pore size of 4~10Å and a molar ration of silica/alumina of 10~300. The zeolite in a state transition metals and phosphorous are not formulated is one or more selected from the zeolite of a ZSM-5 type, a BEA type, a USY type and an MOR type.

Description

Zeolite catalyst for decomposition of nitrous oxide and nitrogen oxides and a method for preparing the same

The present invention relates to a zeolite catalyst for decomposition of nitrous oxide (N ₂ O) and nitrogen oxides (NOx) and a method for preparing the same. More specifically, the present invention relates to nitrous oxide (hereinafter referred to as N) to improve hydrothermal stability of zeolite catalyst. ₂ O.) and nitrogen oxides (hereinafter referred to as NOx) are characterized by stabilizing by modifying the phosphorus and transition metal precursor in a molecular sieve excellent in decomposition properties. That is, the present invention is easy to deactivate -Si-OH-Al- high temperature under a high humidity atmosphere of NOx and N ₂ O decomposition activity by the formula using an appropriate amount of a transition metal and of a molecular sieve having a framework under hydrothermal conditions It was to maintain a long time stably.

Therefore, the present invention is inexpensive and durable in removing N ₂ O, which has a high global warming index, and NOx, which is an air pollution source, by using catalysts, which are emitted from sources such as factories, power plants, automobiles, and incinerators. To provide a catalyst.

Nitrous oxide (N ₂ O) is one of the representative global greenhouse gases with a Global Warming Potential (GWP) of 310 and 6% of the global warming gases. N ₂ O is emitted from high-temperature combustion devices or nitric acid manufacturing plants that use air in the air, and adipic acid and caprolactam manufacturing plants, which are raw materials of nylon, and are mostly emitted with NOx components. Is common. In the last few years, a technological approach to reducing global greenhouse gases has been underway, and today, the use of zeolite catalysts to decompose and remove nitrous oxide and nitrogen oxides has been mainly used.

Here, zeolites are largely classified by their structure. Zeolites generally refer to silicon aluminum oxide (Al ₂ O ₃ SiO ₂ , alumina silica), and alumina (Al ₂ O ₃ ) and silica (SiO ₂ ). Depending on the proportions of the mixtures with each other, their properties and uses are different. Zeolite is divided into MFI type, BEA type, USY type, MOR type, FER type, MEL type, MAZ type, FAU type, OFF type, HEU type zeolite according to IUPAC nomenclature according to the ratio of alumina and silica and its structure. . In particular, among the MFI (pentacil type) zeolites, ZSM-5, ZSM-22, and the like are typical examples.

The most principle approach to treating N ₂ O is to decompose it directly into N ₂ and O ₂ using a catalyst, but has a problem of poor catalytic efficiency due to oxygen and water vapor contained in the off-gas (USP 5,171,553). In order to overcome such degradation efficiency, a selective catalytic reduction (SCR) using hydrocarbon or ammonia as a reducing agent has been proposed. Techniques have been proposed to effectively remove N ₂ O components by reacting some transition metals, including iron or copper, with hydrocarbons or ammonia as reducing agents (EP-A 0914866, USP4,571,329).

As mentioned above, N ₂ O may be discharged alone or together with the NO x component. In particular, when N ₂ O is discharged together with the NO x component, it is more economical to remove N ₂ O and NO x simultaneously from one catalyst than to treat them separately. N ₂ O decomposition catalysts can be broadly classified into noble metal catalysts such as Pt, Pd, Ru, and oxide catalysts such as zeolites and metal oxides, and have different characteristics. USP 5,171,553 proposes a zeolite catalyst comprising a metal selected from cobalt, rhodium, iridium, ruthenium and platinum. As is known, the supported catalysts exhibit excellent decomposition activity even at relatively low temperatures, but at the same time, they have low durability against sintering and low poisoning of sulfur compounds in the presence of a reducing agent in the simultaneous removal of N ₂ O and NOx. It is disadvantageous in terms of economical price.

Meanwhile, WO 00/48715 and WO 2003/105998 propose a BEA or MFI zeolite catalyst containing iron instead of a noble metal catalyst for simultaneous removal of N ₂ O and NO x.

N ₂ O does not require a reducing agent because it directly decomposes, but NOx can be removed only by using a reducing agent. Therefore, these patents report that simultaneous removal of N ₂ O and NO x is possible by adding ammonia as a reducing agent. However, the simultaneous removal of N ₂ O and NOx generates a large amount of high temperature moisture due to the use of moisture contained in the exhaust gas itself or a reducing agent and causes deactivation of the catalyst. In particular, zeolite-based molecular sieves which are frequently used to remove N ₂ O and NO x have high disadvantages of inactivation by sintering and resistance to sulfur compounds but low resistance to moisture. Appl. Cat. A, 184, 249-256 (1999) In order to directly decompose N ₂ O iron (Fe) have been applied to the supported catalyst ZSM-5, 480 ^o scored N ₂ O decomposition destruction efficiency of 80% at a temperature of C However, it has a disadvantage in that it is degraded by moisture. WO 99/049954, JP 05103953 and 07,213,864 in the iron formula I as the use of a zeolite catalyst to N ₂ O catalytic decomposition of methane, propane, LPG, etc. When used as a reducing agent 400 ^o a low temperature in the water, oxygen, sulfur dioxide, such as C or less It is reported to exhibit high initial N ₂ O degradation properties in the presence of 100%. However, when used for a long time, the degradation activity decreases, especially when the presence of water at 360 ^° C, 2% is reported to be drastically reduced, it is not considered that the emission of unreacted hydrocarbons and carbon monoxide. In order to solve this problem, in JP 09000884, iron-modified zeolite and platinum and palladium precious metal supported catalysts were physically mixed to obtain 60% N ₂ O decomposition at 450 ^o C. Got it.

As mentioned above, the iron-modified zeolite catalyst has good initial decomposition activity, but lacks hydrothermal stability to treat N ₂ O, NOx gas in waste gas at high temperature, such as a nitric acid plant, and the treatment efficiency is low. As a result, there is an increasing demand for zeolite catalysts having hydrothermal stability.

The present inventors have diligently studied the above requirements, and as a result, an ammonium zeolite catalyst (NH ₄ -ZSM-5, NH ₄ -BEA), which is a conventional zeolite catalyst for N ₂ O and NOx decomposition, or a zeolite catalyst modified with a transition metal by the formula (P, phosphorus) or the like, when N ₂ O and NOx decomposition, removal high temperatures, under high humidity conditions is also higher than the conventional zeolite catalyst it has been found to maintain the NOx and N ₂ O decomposition. That is, the present invention shows high activity in decomposing N ₂ O even under high temperature and high humidity conditions, as well as zeolite for decomposing N ₂ O and NO x which ensures hydrothermal stability that can be applied for a long time without reducing catalyst performance. Its purpose is to provide a catalyst and a method for its preparation, and furthermore, to provide a method for decomposing and removing N ₂ O and NO x.

The zeolite catalyst for the simultaneous decomposition of nitrous oxide (N ₂ O), nitrogen oxides (NOx) or nitrous oxide and nitrogen oxides of the present invention is a zeolite modified with at least one transition metal and phosphorus (P) selected from Fe, Co and Cu It is characterized by that.

In addition, the present invention is a nitrous oxide, nitrogen oxide or nitrous oxide, nitrogen oxide from the gas containing nitrous oxide, nitrogen oxide or a mixture thereof in a concentration of 100 ~ 10,000 ppm of 100 to 10,000 ppm each using the zeolite catalyst Its characteristics are its simultaneous decomposition and removal method.

When the phosphorus-modified zeolite catalyst of the present invention is used for the decomposition and removal of nitrous oxide and nitrogen oxide contained in the contaminated gas, hydrothermal stability is ensured more than that of the conventional zeolite catalyst, and the activity is maintained for a long time even in the harsh process environment. It is expected to be able to effectively decompose and remove nitrous oxide and nitrogen oxide contained in the contaminated gas.

The zeolite catalyst for the simultaneous decomposition of nitrous oxide (N ₂ O), nitrogen oxides (NOx) or nitrous oxide and nitrogen oxides of the present invention is a zeolite modified with at least one transition metal and phosphorus (P) selected from Fe, Co and Cu It is characterized by that.

The zeolite may be a zeolite having a molar ratio of silicon (SiO ₂ ) / alumina (Al ₂ O ₃ ) of 10 to 300 and a pore size of 2 to 12 kPa (preferably 4 to 10 kPa). .

In this case, when the molar ratio of silicon / alumina is less than 10, a long-term durability problem of the catalyst performance occurs, and when it exceeds 300, a problem of initial activity shortage occurs. In addition, if the pore size is less than 2 mm 3, the pore size may be difficult to be used for catalytic decomposition. If the pore size is more than 12 mm 3, structural stability may occur.

The zeolite before the transition metal and phosphorus is modified can be used as long as it is a zeolite composed of silicon (Si) and aluminum (Al), including ZSM-5 type, BEA type, USY type, MOR type, and these zeolites are H ⁺ , NH ₄ ⁺ or other substituted cation may be used, through which the object of the present invention can be sufficiently achieved.

Here, ZSM-5 type, BEA type, USY type and MOR type each refer to ZSM-5, BEA, USY and MOR substituted with cations such as H ⁺ and NH ₄ ⁺ of zeolite, and the expression method is ZSM- Specific examples of 5 are generally represented by HZSM-5, NH ₄ -ZSM-5, and other substituted cations-ZSM-5. Hereinafter, ZSM-5 substituted with a cation, BEA substituted with a cation, USY substituted with a cation, and MOR substituted with a cation are defined as ZSM-5, BEA, USY, and MOR types by their higher conceptual expressions. do.

The phosphorus (P, Phophorus) is preferably modified to be 0.03 to 15% by weight relative to the total weight of the modified zeolite. Herein, when the modified weight% of phosphorus is less than 0.03 wt%, the hydrothermal stability necessary for improving catalyst durability may be reduced, and when it exceeds 15 wt%, there is a problem in that decomposition activity is deteriorated.

In addition, the transition metal is preferably modified to be 0.01 to 45% by weight relative to the total weight of the modified zeolite. Here, when the modified weight percent of the transition metal exceeds 0.01 wt% or exceeds 45 wt%, there is a problem in that catalytic decomposition activity decreases.

It is preferable to use any one selected from H ₃ PO ₄ , (NH ₄ ) ₂ HPO ₄ and NH ₄ H ₂ PO ₄ as a precursor of phosphorus to modify the phosphor in zeolite, and the phosphorus is combined with a transition metal precursor. After modification, it is present in the form of metal phosphate in the zeolite catalyst.

In the present invention, the concentration of nitrous oxide, nitrogen oxide, or a mixture thereof, which is generally discharged from a nitric acid plant using the zeolite catalyst is 100 to 10,000 ppm, respectively, and these gases are simultaneously decomposed using the zeolite catalyst of the present invention. The removal method has its features. However, the present invention is not limited to the numerical limit of the concentration of nitrous oxide, nitrogen oxide or a mixture thereof.

The decomposition removal method is NH ₃ contained in the gas And at least one selected from hydrocarbons as a reducing agent, or NH ₃ as a reducing agent separately from the gas. And It is preferable to add one or more selected from hydrocarbons.

It is preferable to use the present invention in the decomposition of nitrous oxide (N ₂ O) and nitrogen oxides (NOx) of the gas at a temperature of the gas at 420 ° C to 650 ° C (more preferably, 450 ° C to 630 ° C). In this case, when the temperature of the gas is less than 420 ° C., there is a problem in that the N ₂ O conversion rate is low.

Decomposition and removal method of the present invention is characterized in that the direct decomposition or selective reduction decomposition when the decomposition of the nitrous oxide or nitrogen oxides.

Hereinafter, the embodiment of the present invention will be described in more detail. However, the scope of the present invention is not limited by the following example.

[ Example ]

Example  One

P- ZSM -5 Catalyst Preparation

4.12 g of 85% phosphoric acid (H ₃ PO ₄ ) was mixed with 200 mL of distilled water, followed by stirring. Then, 25 g of ZSM-5 (average pore size 5.5 ± 0.2 mm) zeolite was added thereto, and vigorously stirred at room temperature for 6 hours. Mixed. And it was stirred at 60 ^° C. and then dried at 650 ^° C for 6 hours to prepare P-ZSM-5.

Example 2

Fe / P-ZSM-5 Catalyst Preparation

After milling and milling P-ZSM-5 obtained in Example 1, 20 g was added to a solution in which 5.29 g of Fe (NO ₃ ) ₃ 9H ₂ O was dissolved in 120 ml of distilled water, followed by stirring for 6 hours. After stirring and drying at 60 ^° C. and then calcined at 650 ^° C for 6 hours to produce Fe / P-ZSM-5.

Example  3

[ FeP ]- ZSM -5 Catalyst Preparation

4.12 g of 85% phosphoric acid and 3.6 g of Fe (NO ₃ ) ₃ 9H ₂ O were mixed with 200 mL of distilled water, followed by stirring. 25 g of the same ZSM-5 as used in Example 1 was added thereto, followed by vigorous stirring at room temperature for 6 hours. After stirring and drying at 60 ^° C. and then calcined at 650 ^° C for 6 hours to prepare [FeP] -ZSM-5.

Example 4

P- BEA  Catalyst manufacturing

After mixing 4.88 g of 85% phosphoric acid in 200 mL distilled water and stirring, 25 g of BEA zeolite (average pore size 6.9 ± 0.2 mm) was added thereto, followed by vigorous stirring at room temperature for 6 hours. After stirring and drying at 60 ^° C. and then calcined at 650 ^° C for 6 hours to prepare a P-BEA.

Example  5

Fe / P- BEA  Catalyst manufacturing

After milling and milling the P-BEA obtained in Example 4, 20 g was added to a solution in which 5.22 g of Fe (NO ₃ ) ₃ .9H ₂ O was dissolved in 120 ml of distilled water, followed by stirring for 6 hours. After stirring and drying at 60 ^° C. and then calcined at 650 ^° C for 6 hours to produce Fe / P-BEA.

Example 6

[FeP] -BEA Catalyst Preparation

4.88 g of 85% phosphoric acid and 7.1 g of Fe (NO ₃ ) ₃ .9H ₂ O were mixed with 200 mL of distilled water, followed by stirring. 25 g of the same BEA zeolite as used in Example 4 was added thereto, followed by vigorous stirring at room temperature for 6 hours. After stirring and drying at 60 ^° C. and then calcined at 650 ^° C for 6 hours to produce [FeP] -BEA.

Comparative example  1 to 5

Fe - ZSM -5 Catalyst Preparation

A were dissolved _{Fe (NO 3) 3 · 9H} 2 O in the calculated 200 mL of distilled water, a solution of the same ZSM-5 type zeolite or BEA-type zeolite as used in Example 1, 50g of the dispersion was stirred for 6 hours. Then calcined (650 ^° C. for 6 hours) after further stirring until all the moisture has evaporated at about 60 ° C., or 6 hours at 650 ^° C. in a kiln after stirring, filtering and washing at 20 ° C. for 24 hours. The catalyst was prepared by solid reaction. Table 1 below describes catalyst preparation conditions and supporting methods.

Comparative example  6

Fe - DeAl ZSM -5 Catalyst Preparation

The NH ₄ -ZSM-5 type zeolite of Comparative Example 1 was subjected to hydrothermal treatment to prepare a dealuminated zeolite catalyst (hereinafter referred to as "Fe-DeAl-ZSM-5 catalyst"). To this end, the same ZSM-5 zeolite as used in Example 1 was completely dried after treatment for 24 hours in a steam atmosphere of a 500 ^° C. reactor. The obtained Fe-DeAl-ZSM-5 was uniformly mixed with a calculated Fe (NO ₃ ) ₃ .9H ₂ O using a ball mill, and then subjected to a solid reaction at 600 ^° C. for 6 hours in a calcination furnace to obtain a catalyst. Prepared. Table 1 below describes the catalyst preparation conditions.

Preparation conditions of the catalyst described in the comparative example catalyst Zeolite Fe ( NO ₃ ) ₃ 9 H ₂ O  Amount (g) Support method Kinds Addition amount (g) Comparative Example 1 ZSM-5 25 5.17 Drying / firing Comparative Example 2 ZSM-5 25 7.75 Drying / firing Comparative Example 3 ZSM-5 25 10.33 Drying / firing Comparative Example 4 ZSM-5 25 7.75 Ion Exchange / Firing Comparative Example 5 NH ₄ -BEA 25 7.75 Ion Exchange / Firing Comparative Example 6 Fe-DeAl-ZSM-5 25 7.23

Experimental Example

In order to confirm the effect of the present invention, N ₂ O decomposition experiments were performed under the following conditions. 2g of the catalyst of Examples and Comparative Examples were put in a stainless steel reactor, and the reaction temperature was adjusted to 300 to 600 ^° C. using an external heater. In this case, the total flow rate of the reactant and the diluent gas flowing into the reactor was 333.5 ml / min, and gas hourly space velocity (GHSV) was maintained at 10,000 / h. The reaction was analyzed using a NOx analyzer (EUROTRON) and gas chromatography (Gas Chromatography, HP-5890).

Experimental Example  One

[ FeP ]- ZSM -5 catalyst and F- DeAl - ZSM -5 of catalyst N ₂ O  Degradation Activity Experiment

[FeP] -ZSM-5 catalyst of Example 3 and F-DeAl-ZSM-5 of Comparative Example 6 N ₂ O decomposition experiments were carried out under the reaction conditions shown in Table 2 using the catalyst for about 300 hours, and the results are shown in FIG. 1. The catalyst of Example 3 showed 95% or more of N ₂ O decomposition activity even after 300 hours, but the catalyst of Comparative Example 6 was inferior in N ₂ O decomposition activity with time.

Experimental Example  2

N of Fe / P-BEA and [FeP] -BEA catalysts ₂ O Degradation Activity

Using the Fe / P-BEA, [FeP] -BEA catalyst of Examples 5 and 6 and the Fe-BEA catalyst of Comparative Example 5 was compared N ₂ O decomposition activity according to the reaction temperature in the reaction conditions of Table 2, The results are shown in FIG. In particular, the catalyst of Example 5 of the present invention exhibited N ₂ O decomposition activity at 550 ^° C. up to 100%, and exhibited better decomposition characteristics than that of Comparative Example 5 catalyst at almost all reaction temperatures. In addition, the [FeP] -BEA catalyst of Example 6 showed higher N ₂ O decomposition activity from about 550 ^° C. or more than the catalyst of Comparative Example 5.

Experimental Example  3

Fe / P- ZSM With -5 catalyst Fe - ZSM Activity Comparison of -5 Catalyst

The Fe / P-ZSM-5 catalyst of Example 2 and the Fe-ZSM-5 catalysts of Comparative Examples 2 and 3 were tested for N ₂ O decomposition activity under the reaction conditions shown in Table 2 below, and the results are shown in FIG. 3. Through this, the Fe / P-ZSM-5 catalyst of Example 2 exhibited N ₂ O decomposition activity up to 100% at 500 ^o C or more, and excellent decomposition properties than the catalysts of Comparative Examples 2 and 3 at all reaction temperatures. Indicated.

Experimental Example 4

N of [FeP] -ZSM-5 Catalyst and F-ZSM-5 Catalyst ₂ O Degradation Activity Test

Using the [FeP] -ZSM-5 catalyst of Example 3 and the Fe-ZSM-5 catalyst of Comparative Examples 1 and 4, the results of N ₂ O decomposition activity in the reaction conditions shown in Table 2 are shown in FIG. Through this, the [FeP] -ZSM-5 catalyst exhibited N ₂ O decomposition activity up to 100% at 500 ^° C. or higher, and showed better decomposition characteristics than the catalysts of Comparative Examples 1 and 4 at all reaction temperatures.

Experimental Example 5

Fe / P-ZSM-5 catalyst, N of [FeP] -ZSM-5 catalyst ₂ O and NOx Degradation Activity

N ₂ O and NO x when ammonia (NH ₃ ) is present as a reducing agent under the reaction conditions shown in Table 2 using the Fe / P-ZSM-5 and [FeP] -ZSM-5 catalysts of Examples 2 and 3. The decomposition experiment was performed, and the results are shown in FIG. 5. In the presence of an ammonia reducing agent, 100% N ₂ O decomposition was exhibited from the reaction temperature of 450 ^o C. In addition, NH ₃ at a reaction temperature of 400 ^o C Simultaneous decomposition of N ₂ O and NO x according to the concentration change is shown in FIG. 6. The [FeP] -ZSM-5 catalyst of the present invention exhibited almost 100% NOx decomposition characteristics in the presence of N ₂ O.

Experimental Example 6

NH ₃  N when reducing agent is added ₂ O Degradation Activity

N ₂ when NH ₃ is present under the reaction conditions of Table 2 using the [FeP] -ZSM-5 catalyst of Example 3 and the F-DeAl-ZSM-5 catalyst of Comparative Example 6, but NOx is not included. The results of the O decomposition reaction are shown in FIG. 7. At the reaction temperature of 350 ^° C. or higher, all showed up to 100% N ₂ O decomposition activity, and the catalyst of Example 3 of the present invention showed excellent N ₂ O decomposition characteristics at lower temperature.

Experimental Example 7

After steam treatment, NH ₃  N when reducing agent is added ₂ O Degradation Activity Test

In order to confirm that the catalyst of the present invention exhibits more excellent hydrothermal stability characteristics and maintains excellent activity even in a long time N ₂ O decomposition process in which water is present, it is compared with the [FeP] -ZSM-5 catalyst of Example 3 The Fe-ZSM-5 catalyst of 2 was treated at 760 ^° C. in a 100% steam atmosphere for 24 hours, and then experiments were performed under the reaction conditions shown in Table 2 below, and the results are shown in FIG. 8. The catalyst of Example 3 of the present invention showed high N ₂ O decomposition activity even after hydrothermal treatment.

In the experiment  Reaction conditions of different catalytic activity tests division Test gas concentration included in injected gas Reductant NH ₃ H ₂ O input flow rate (ml / hr) N ₂ O NOx Concentration (ppm) Input flow rate (ml / min) Concentration (ppm) Input flow rate (ml / min) Concentration (ppm) Input flow rate (ml / min) Experimental Example 1 1,500 0.5 - - - - 0.5 Experimental Example 2 1,500 0.5 - - - - 0.5 Experimental Example 3 1,500 0.5 1,000 0.334 1,000 0.334 0.5 Experimental Example 4 1,500 0.5 1,000 0.334 1,000 0.334 0.5 Experimental Example 5 1,500 0.5 - - 1,000 0.334 0.5 Experimental Example 6 1,500 0.5 1,000 0.334 1,000 0.334 0.5 Experimental Example 7 1,500 0.5 - - - - 0.5

Through the above experimental example, P-ZSM-5, P-BEA, [FeP] -ZSM-5, [FeP] -BEA, Fe / P-ZSM-5 and Fe / P-BEA catalysts of the present invention The hydrothermal stability was improved over the catalysts such as Fe-ZSM-5, Fe-BEA, and F-DeAl-ZSM-5 to confirm that the long-term stability of the catalyst was secured.

1 is a data comparing the results of the N ₂ O decomposition activity of the catalyst of Example 3 and Comparative Example 6 according to Experimental Example 1.

Figure 2 is a data comparing the results of the N ₂ O decomposition activity of the catalyst of Examples 5,6 and Comparative Example 5 according to Experimental Example 2.

Figure 3 is a data comparing the results for the N ₂ O decomposition activity test of the catalyst of Example 2 and Comparative Examples 2, 3 according to Experimental Example 3.

Figure 4 is a data comparing the results of the N ₂ O decomposition activity test of the catalyst of Example 3 and Comparative Examples 1, 4 according to Experimental Example 4.

5 is data comparing the results of the N ₂ O decomposition activity test of the catalyst of Example 3 and Comparative Example 6 according to Experimental Example 5.

Figure 6 is the result data for the N ₂ O and NOx decomposition activity test of the catalyst of Example 3 according to Experimental Example 5.

7 is a data comparing the results of the N ₂ O decomposition activity of the catalyst of Example 3 and Comparative Example 6 according to Experimental Example 6.

8 is data comparing the results of the catalyst of Example 3 according to Experimental Example 7 and the N ₂ O decomposition activity test of Comparative Examples 2 and 6.

Claims (9)

Simultaneous decomposition of nitrous oxide (N ₂ O), nitrogen oxides (NOx) or nitrous oxide and nitrogen oxides, characterized in that the zeolite modified together with at least one transition metal and phosphorus (P) selected from Fe, Co and Cu. Zeolite catalyst. The zeolite catalyst of claim 1, wherein the zeolite has a molar ratio of silica (SiO ₂ ) / alumina (Al ₂ O ₃ ) of 10 to 300 and a pore size of 4 to 10 GPa. The zeolite catalyst according to claim 1, wherein the zeolite before the transition metal and phosphorus is modified is ZSM-5, BEA, USY and MOR. The zeolite catalyst according to claim 1, wherein the phosphor is modified to be 0.03 to 15 wt% based on the total weight of the modified zeolite. The zeolite catalyst of claim 1, wherein the transition metal is modified to be 0.01 to 45 wt% based on the total weight of the modified zeolite. The phosphorus precursor for modifying the phosphorus zeolite is any one selected from H ₃ PO ₄ , (NH ₄ ) ₂ HPO ₄ and NH ₄ H ₂ PO ₄ , wherein the phosphorus is a transition metal Zeolite catalyst, characterized in that it is modified with a precursor, present in the form of metal phosphate in the zeolite catalyst. Nitrous oxide (N ₂ O), nitrogen oxides from a gas containing nitrous oxide, nitrogen oxide or a mixture thereof in a concentration of 100 to 10,000 ppm by using the zeolite catalyst of any one of claims 1 to 6 (NOx) or simultaneous decomposition and removal of nitrous oxide and nitrogen oxides. 8. The decomposition removal method according to claim 7, wherein the decomposition removal method is direct decomposition or selective reduction decomposition. The method of claim 8, wherein the selective reduction is NH ₃ And at least one selected from hydrocarbons as a reducing agent.

Images