JP2012521288A - Zeolite catalyst loaded with iron ions, method for producing the same, and method for reducing nitrous oxide alone or nitrous oxide and nitric oxide simultaneously with an ammonia reducing agent using the catalyst - Google Patents

Abstract

  The present invention relates to the production of a zeolite catalyst loaded with iron ions for the sole reduction of nitrous oxide, which is a greenhouse gas, or the simultaneous reduction of nitrous oxide and nitrogen monoxide, which is an air pollutant gas, with an ammonia reducing agent. The present invention relates to a method, a catalyst produced by the production method, and a method for reducing nitrous oxide alone or simultaneously reducing nitrous oxide and nitric oxide with an ammonia reducing agent using the catalyst. The present invention is a method for producing a zeolite catalyst on which iron ions are supported as a highly efficient catalyst for reducing nitrous oxide alone or simultaneously reducing nitrous oxide and nitric oxide with an ammonia reducing agent. It is an object of the present invention to provide a method for reducing the temperature of nitrous oxide by itself or reducing the temperature of nitrous oxide and nitric oxide simultaneously by using an ammonia reducing agent.

Description

  The present invention provides a method for producing a zeolite catalyst carrying iron ions for simultaneously reducing nitrous oxide and nitric oxide with an ammonia reducing agent, a catalyst produced by the production method, and a catalyst using the catalyst. More specifically, a method for simultaneously reducing nitrogen oxide and nitric oxide is obtained by treating a zeolite catalyst carrying iron ions with water, or carrying iron ions on a moisture-treated zeolite and then using the catalyst. The present invention relates to a technique for reducing nitrous oxide alone or nitrous oxide and nitric oxide simultaneously at a low temperature with an ammonia reducing agent.

About 25% of nitrous oxide is released by fixed industrial sources. The released nitrous oxide is usually present with nitric oxide in an oxygen rich atmosphere. Nitric oxide emitted from industrial fixed sources is removed by selective catalytic reduction (SCR) technology that utilizes reducing agents such as ammonia, hydrogen, and carbon monoxide. Various types of catalysts have been developed to apply the above technology at low and high temperatures, of which V ₂ O ₅ —TiO ₂ based catalyst systems have been commercialized and mainly used with ammonia reducing agents. Yes. In order to reduce nitrous oxide, a zeolite catalyst on which iron is supported is mainly used. In this case, a hydrocarbon such as methane or propane or ammonia is used as a reducing agent.

  When hydrocarbon is used as a reducing agent, nitrous oxide can be reduced even at a temperature of less than 400 ° C. However, when ammonia is used as a reducing agent, a temperature of 400 ° C or higher is used to reduce nitrous oxide. is necessary.

  Therefore, it is not easy to simultaneously reduce nitrous oxide and nitric oxide using a single reducing agent.

  The prior art will be described below. In U.S. Pat. Nos. 5,198,403, 5,300, and 472, titanium oxide is replaced with any oxide of W, Si, B, Al, P, Zr, Ba, Y, La, and Ce. A catalyst is produced by mixing any of oxides of Y, Nb, Mo, Fe, and Cu, and ammonia is used as a reducing agent that selectively reduces nitric oxide. 50 to 99% of the catalyst thus produced is composed of titanium oxide. In this case, 81.1% to 94.3% of nitric oxide was reduced at 360 to 500 ° C.

  In US Published Patent Publication No. US2002 / 0127163A1, International Publication No. WO02 / 072245A2, Korean Published Patent Publication No. 10-2004-0010608, for selective reduction of nitric oxide using ammonia, BETA, ZSM, MORD, A catalyst is manufactured by ion-exchanging Fe, Cu, Co, Ce, Pt, Rh, Pd, Ir, Mg, or the like with a zeolite such as Y. Among the catalysts produced in this way, a catalyst having activity in the selective reduction reaction of nitrous oxide was selected to selectively reduce nitrous oxide and nitrous oxide. The conversion rates of nitrous oxide at 450 and 500 ° C. were 80% and 99%, respectively.

  In US Pat. No. 6,682,710B1, published US Pat. No. 2004 / 0192538A1, and US Pat. No. 7,238,641B2, nitrous oxide and nitric oxide are removed using a catalyst obtained by ion exchange of iron ions in FER zeolite. A method is disclosed. US Pat. No. 6,872,372 B1 discloses that nitrous oxide can be selectively reduced at a temperature of 350 ° C. or lower when palladium, rhodium, gold, or the like is added to a zeolite catalyst containing iron ions. . Saturated hydrocarbons such as methane and propane were used as the reducing agent.

  In Japanese Patent Publication No. 2006-281026, in order to reduce nitrogen oxide, titanium oxide and Cr, Mg, Fe, Co, Ni, Cu, Mo, Ru, Rh, Pd, Ag, In, A catalyst in which any one selected from Sn, W, Pt, Au, Pb or one of its oxides is mixed is used.

  The above patent documents disclose that nitrous oxide can be reduced at a temperature of 350 ° C. or lower when a hydrocarbon is used as a reducing agent. However, when ammonia is used as the reducing agent, the catalyst disclosed in the above patent documents requires a temperature of 360 ° C. or higher in order to reduce nitrous oxide alone.

  Further, when ammonia is used as a reducing agent, the above patent documents disclose 400 ° C. or more as an effective temperature for simultaneously reducing nitric oxide and nitrous oxide.

  Therefore, when using ammonia as a reducing agent, not only the temperature for reducing nitrous oxide alone, but also the temperature for simultaneously reducing nitrous oxide and nitrous oxide is used as a reducing agent. The production of a catalyst that can be kept at the same level as the above, and the development of simultaneous reduction technology are required.

  The present invention has been devised to solve the above-mentioned problems of the prior art, and iron ions capable of simultaneously reducing nitrous oxide and nitric oxide at a reaction temperature of 300 to 400 ° C. are supported by an ammonia reducing agent. Another object of the present invention is to provide a method for producing a zeolite catalyst and the catalyst.

  Another object of the present invention is to provide a method of reducing and reducing nitrous oxide at a low reaction temperature using a zeolite catalyst in which iron ions are supported by an ammonia reducing agent.

  Another object of the present invention is to provide a method for simultaneously reducing and reducing nitrous oxide and nitric oxide at a low reaction temperature using a zeolite catalyst in which iron ions are supported by an ammonia reducing agent.

  A process for producing a zeolite catalyst carrying iron ions for reducing nitrous oxide alone or nitrous oxide and nitric oxide simultaneously with an ammonia reducing agent according to one aspect of the present invention for solving the above-mentioned problems (A) Pretreatment of zeolite with water at a high temperature and (B) Zeolite pretreated in the step (A) or Zeolite that has not undergone the step (A) and has not been pretreated. A step of supporting iron ions by a precursor material solution of iron ions, (C) filtering and drying the zeolite particles supporting iron ions in the step (B), and (D) step (C). Repeating the steps (B) and (C) to increase the iron content of the powder dried in step (E), and (E) calcining the catalyst produced in step (D) in air, (F) Before Wherein the zeolite has not undergone step (A) the (E) stage to the through-obtained catalyst comprising a step of treating at high temperatures by moisture.

According to another aspect of the present invention, there is provided a method for producing an iron ion-supported zeolite catalyst, wherein in the step (A), the zeolite contains any of BEA, MFI, MOR and FER, _{The 2} O ₃ / SiO ₂ molar ratio is 5 to 100, and the zeolite contains any one of sodium, ammonium and hydrogen cations.

  According to still another aspect of the present invention, there is provided a method for producing a zeolite catalyst loaded with iron ions, wherein the zeolite is heated at 400 to 600 ° C. Supply zeolite for 0.1 to 2 hours under atmosphere to treat moisture.

According to still another aspect of the present invention, there is provided a method for producing a zeolite catalyst supporting iron ions, wherein the step (B) includes iron nitrate hydrate (Fe (NO ₃ ) _3. 9H ₂ O) is used to adjust the concentration to 0.001 to 1.0 molar.

  According to still another aspect of the present invention, there is provided a method for producing a zeolite catalyst on which iron ions are supported, wherein the solution of the iron ion precursor material is water-treated in the step (A), or the step (A). The zeolite which has not passed through is added at a weight ratio of 0.1 to 3.0, and stirred at 10 to 35 ° C. for 5 to 30 hours.

  According to still another aspect of the present invention, in the method for producing a zeolite catalyst supporting iron ions, the step (C) includes removing the cake obtained by filtering the zeolite slurry obtained in the step (B). It is washed with 500 to 2000 ml of ionized distilled water, and the zeolite carrying the washed iron ions is dried at 100 to 120 ° C. in air for 5 to 24 hours.

  In the method for producing a zeolite catalyst loaded with iron ions according to still another aspect of the present invention, in the step (D), the step (B) and the step (C) are repeated 2 to 5 times.

  According to still another aspect of the present invention, there is provided a method for producing a zeolite catalyst loaded with iron ions, wherein the step (E) is performed by converting the zeolite obtained in the step (D) from 400 to 600 in air. Bake for 5 hours.

  According to still another aspect of the present invention, there is provided a method for producing an iron ion-supported zeolite catalyst, wherein the step (F) includes the step (B), the step (C), from the zeolite not subjected to the step (A). After heating at 400 to 600 ° C. with respect to the zeolite carrying the iron ions obtained through the steps (D) and (E), the water content is 0.1 to 5 times the weight of the zeolite. Is supplied for 0.5 to 2 hours under a nitrogen atmosphere.

  A zeolite catalyst loaded with iron ions according to one feature of the present invention for solving the above-mentioned problem is produced by the above-described method for producing a zeolite catalyst, and the zeolite loaded with iron ions is activated, It is configured to reduce 70 to 100% of nitrous oxide alone or each of nitrous oxide and nitric oxide simultaneously at 300 to 400 ° C. with an ammonia reducing agent.

  A method for simultaneously reducing nitrous oxide or nitrous oxide and nitric oxide with an ammonia reducing agent according to one aspect of the present invention for solving the above-mentioned problems is as follows: nitrous oxide alone or nitrous oxide and monoxide Nitrogen is supplied simultaneously and contacted with the zeolite catalyst loaded with activated iron ions produced by the above-described method for producing a zeolite catalyst, and nitrous oxide alone or nitrous oxide and nitric oxide is converted by an ammonia reducing agent. At the same time, it is reduced and reduced at a low catalytic reaction temperature.

  A method for reducing nitrous oxide or nitrous oxide and nitric oxide using ammonia as a reducing agent according to still another aspect of the present invention is a catalyst reaction temperature at the time of reducing the nitrous oxide and nitric oxide. Is 300-500 degreeC which is low temperature.

  In the present invention, the zeolite is loaded with iron ions after moisture treatment, or the zeolite catalyst loaded with iron ions is loaded with an iron ion, and the zeolite catalyst loaded with iron ions is used to suboxidize with an ammonia reducing agent. Nitrogen alone or nitrous oxide and nitric oxide can be reduced simultaneously at a temperature of 300-500 ° C, using a single reducing agent to improve low temperature activity and simultaneously reduce nitrous oxide and nitric oxide It is a useful invention that can be made and is expected to be industrially utilized.

FIG. 1 is a flowchart showing a production process of a zeolite catalyst supporting iron ions for reducing nitrous oxide alone or nitrous oxide and nitric oxide simultaneously with an ammonia reducing agent. FIG. 2 shows the relationship between the temperature and the conversion rate of nitrous oxide alone by the ammonia reducing agent when the iron zeolite-supported BEA zeolite catalyst produced according to Examples 1, 2 and 3 of the present invention is used. It is a graph. FIG. 3 is a graph showing the relationship between the temperature and the conversion rate of nitrous oxide and nitric oxide by the ammonia reducing agent when the iron zeolite-supported BEA zeolite catalyst produced according to Example 1 of the present invention is used. It is.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the present invention, when it is determined that a specific description related to a known function or a known configuration hinders understanding of the gist of the present invention, a detailed description thereof will be omitted.

  The present invention relates to a method for producing a zeolite catalyst supporting iron ions for simultaneously reducing nitrous oxide and nitric oxide when ammonia is used as a reducing agent, a catalyst produced by the production method, and the catalyst. To provide a method for simultaneously reducing nitrous oxide or nitrous oxide and nitric oxide.

  First, a method for producing a zeolite catalyst carrying iron ions will be described. The method for producing a catalyst according to the present invention includes (A) a stage in which zeolite is pretreated with water at a high temperature, (B) a zeolite pretreated in stage (A), or a zeolite not pretreated in stage (A) The step of supporting the iron ions with the precursor material solution of iron ions in the step (C), the step of filtering the zeolite particles supporting the iron ions in the step (B) and drying, the step (D) and drying in the step (C) Repeating steps (B) and (C) to increase the iron content of the powder, (E) calcination of the catalyst prepared in steps (D) in air, (F) (A) A step of treating the catalyst obtained in the step (E) from the zeolite not subjected to the step with water at a high temperature.

  Hereinafter, each step will be described in detail.

Step (A) is a step in which zeolite is prepared by moisture treatment in order to carry iron ions. The zeolite includes any of Beta (BEA), ZSM-5 (MFI), Mordenite (MOR), and Ferririte (FER). The Al ₂ O ₃ / SiO ₂ molar ratio of the zeolite is 5-100. Outside this range, since the amount of iron ions supported is extremely small, the effect as a catalyst cannot be exhibited. The zeolite contains any one of sodium, ammonium and hydrogen cations. Since iron ions are supported in the zeolite by ion exchange, if other cations are used, the performance of ion exchange with iron ions is reduced. After heating the zeolite prepared in this way at 400-600 degreeC, 0.1-5 times the water | moisture content with respect to the weight of a zeolite is supplied for 0.1-2 hours in nitrogen atmosphere. In order to obtain the water treatment effect of zeolite, it is desirable to perform the water treatment in such a numerical range.

Step (B) is a step of preparing an iron ion solution and supporting iron ions on zeolite. The precursor material of iron ions, iron nitrate hydrate using _{(iron nitrate hydrate, Fe (NO} 3) 3 · 9H 2 O), concentration is adjusted to 0.001 to 1.0 mol. The reason for limiting to such a range is to provide a driving force for the iron ions to exchange ions in the zeolite and to suppress the loading of excess iron ions. Zeolite that has been subjected to moisture treatment in step (A) or a zeolite that has not passed step (A) is added to the iron ion precursor material solution in a weight ratio of 0.1 to 3.0, and 5 to 10 at 35 ° C. Stir for 30 hours. The reason for limiting to such conditions is to maximize the ion exchange amount of iron ions.

  In step (C), the zeolite slurry obtained in step (B) is filtered, and the cake obtained by the filtration is washed with 500 to 2000 ml of deionized distilled water. In this stage, the iron ions in the solution not ion-exchanged in the zeolite are removed by filtration, and the excess iron ions adhering around the zeolite particles are removed by washing. The reason for limiting the amount of distilled water for washing as described above is to increase the effect of removing excess iron ions and to minimize the loss of iron ions supported in the zeolite.

  The washed zeolite loaded with iron ions is dried at 100 to 120 ° C. in air for 5 to 24 hours. The reason for limiting the drying temperature and time is to remove the moisture contained in the zeolite and enhance the effect of additional ion exchange and calcination in the next step.

  Step (D) is a step in which steps (B) and (C) are repeated 2 to 5 times. The reason for limiting the number of times in this manner is to maximize the amount of iron ions supported and to prevent excess iron oxide from adhering around the zeolite particles.

  Stage (E) is a stage in which the zeolite obtained in stage (D) is calcined at 400 to 600 ° C. in air for 1 to 5 hours. The reason for limiting the temperature and time in this way is to remove impurities contained in the catalyst.

  Step (F) is a step of heating a zeolite carrying iron ions obtained through steps (B), (C), (D), and (E) from zeolite that has not passed step (A) at 400 to 600 ° C. After that, 0.1 to 5 times as much water as the zeolite weight is supplied in a nitrogen atmosphere for 0.1 to 2 hours. In the case where iron ions are supported on zeolite that has not passed through the stage (A), the reason for limiting the temperature, the amount of water and the time is to activate the zeolite catalyst on which the iron ions are supported.

  Further, the present invention supports iron ions on zeolite by the above-described catalyst production method, thereby reducing nitrous oxide alone or nitrous oxide and nitric oxide simultaneously with ammonia at a temperature of 300 to 500 ° C. Reduce nitric oxide and nitric oxide.

  Examples will be described below for a clearer understanding of the present invention.

<Example 1>
After supplying 1 liter / min of nitrogen to 8 g of BEA zeolite having an Al ₂ O ₃ / SiO ₂ molar ratio of 25 and heating at 500 ° C., deionized distilled water was flowed at a flow rate of 0.5 ml / min by a syringe pump. For 1 hour. After supplying distilled water, the water-treated BEA zeolite (A) was prepared by cooling to room temperature with the same nitrogen flow rate.

Iron ion solution (B) was prepared by dissolving iron nitrate hydrate _{(Fe (NO 3) 3 ·} 9H 2 O) 1.6g distilled water 1 liter been deionized. 8 g of water-treated BEA zeolite (A) was dispersed in 1 liter of the prepared iron ion solution (B) and stirred at 21 ° C. for 24 hours. The stirred zeolite slurry was filtered to obtain a zeolite cake carrying iron ions. The zeolite cake was washed with 1 liter of deionized distilled water. The washed zeolite cake was dried in air at 105 ° C. for 12 hours. The dried zeolite was added to the iron ion solution described above to exchange the iron ions and dried twice. The finally dried zeolite carrying iron ions was calcined in air at 500 ° C. for 4 hours.

<Example 2>
Iron ion solution (B) was prepared by dissolving iron nitrate hydrate _{(Fe (NO 3) 3 ·} 9H 2 O) 1.6g distilled water 1 liter been deionized. 8 g of BEA zeolite having an Al ₂ O ₃ / SiO ₂ molar ratio of 25 was dispersed in 1 liter of prepared iron ion solution (B) and stirred at 21 ° C. for 24 hours. The stirred zeolite slurry was filtered to obtain a zeolite cake carrying iron ions. The zeolite cake was washed with 1 liter of deionized distilled water. The washed zeolite cake was dried in air at a temperature of 105 ° C. for 12 hours. The process of adding the dried zeolite to the above iron ion solution and exchanging the iron ions for drying was performed twice more. The finally dried zeolite carrying iron ions was calcined at 500 ° C. in air for 4 hours.

  In order to treat the BEA zeolite catalyst carrying iron ions with water, it was heated at 500 ° C. while supplying 1 liter / min of nitrogen to 0.4 g of the calcined catalyst, and then the deionized distilled water was injected with a syringe pump. It was supplied at a flow rate of 0.017 ml / min for 1 hour. After supplying distilled water, it was cooled to room temperature with the same nitrogen flow rate as above.

<Example 3>
In order to compare the catalysts of Example 1 and Example 2, a BEA zeolite carrying iron ions not subjected to moisture treatment was prepared. Iron ion solution (B) was prepared by dissolving iron nitrate hydrate _{(Fe (NO 3) 3 ·} 9H 2 O) 1.6g distilled water 1 liter been deionized. 8 g of BEA zeolite having an Al ₂ O ₃ / SiO ₂ molar ratio of 25 was dispersed in 1 liter of prepared iron ion solution (B) and stirred at 21 ° C. for 24 hours. The stirred zeolite slurry was filtered to obtain a zeolite cake carrying iron ions. The zeolite cake was washed with 1 liter of deionized distilled water. The washed zeolite cake was dried in air at 105 ° C. for 12 hours. The process of adding the dried zeolite to the above iron ion solution and exchanging the iron ions for drying was performed twice more. The finally dried zeolite carrying iron ions was calcined in air at 500 ° C. for 4 hours.

<Example 4>
In order to test the reactivity of the catalysts according to Examples 1, 2 and 3 to the reduction reaction of nitrous oxide alone with an ammonia reducing agent, 0.4 g of the catalyst of each example was placed in a 1/2 ″ stainless steel tube reactor. The temperature of the reactor was raised from room temperature to 500 ° C. at a rate of 4 ° C./min using an electric furnace, 400 ppm of nitrous oxide was supplied to the reactor, and 400 ppm of ammonia reducing agent The oxygen concentration in the reaction gas was adjusted to 3,000 ppm, the total flow rate of the reaction gas was maintained at 0.4 l / min using nitrogen, and the space velocity (GHSV) was 20,000 hr ^−1. After the reaction, the concentration of nitrous oxide was measured by an on-line gas analyzer (manufactured by SIEMENS) for gas component analysis.

FIG. 2 shows the relationship between the temperature and the conversion rate of nitrous oxide alone by the ammonia reducing agent when the iron zeolite-supported BEA zeolite catalyst produced according to Examples 1, 2 and 3 of the present invention is used. It is a graph. FIG. 2 shows the results of experiments conducted under the conditions of space velocity: 20,000 hr ⁻¹ , total content: 0.4 l / min, N ₂ O: 400 ppm, O ₂ : 3,000 ppm, NH ₃ : 400 ppm.

  The conversion rates of nitrous oxide with the catalysts prepared according to Examples 1, 2 and 3 were 89%, 69% and 27%, respectively, at a reaction temperature of 350 ° C. This shows that the conversion rate of nitrous oxide is much higher in the catalyst in which iron ions are supported on the water-treated BEA zeolite than in the BEA zeolite in which iron ions not subjected to the water treatment are supported.

<Example 5>
In order to test the reactivity of the catalyst according to Example 1 to the simultaneous reduction of nitrous oxide and nitric oxide with an ammonia reducing agent, 0.4 g of catalyst is placed in the middle in a 1/2 "stainless steel tube reactor. The temperature of the reactor was increased from normal temperature to 500 ° C. at a rate of 4 ° C./min using an electric furnace, 400 ppm of nitrous oxide was supplied to the reactor, and 800 ppm of ammonia reducing agent was used. The oxygen concentration in the reaction gas was adjusted to 3,000 ppm, and the total flow rate of the reaction gas was maintained at 0.4 l / min using nitrogen, and the space velocity (GHSV) was maintained at 20,000 hr- ¹ . After the reaction, the concentrations of nitrous oxide and nitric oxide were measured by an on-line gas analyzer (manufactured by SIEMENS) for gas component analysis.

FIG. 3 is a graph showing the relationship between the temperature and the conversion rate of nitrous oxide and nitric oxide by the ammonia reducing agent when the iron zeolite-supported BEA zeolite catalyst produced according to Example 1 of the present invention is used. It is. FIG. 3 shows the results of experiments conducted under the conditions of space velocity: 20,000 hr ⁻¹ , total content: 0.4 l / min, NO: 400 ppm, N ₂ O: 400 ppm, O ₂ : 3,000 ppm, NH ₃ : 800 ppm. Indicates.

  The conversion of nitrous oxide and conversion of nitric oxide with the catalyst prepared according to Example 1 was 75% and 100% at a reaction temperature of 350 ° C., respectively. This shows that nitrous oxide and nitric oxide can be simultaneously reduced by a single ammonia reducing agent.

  As described above, the present invention has been described based on exemplary embodiments. However, various modifications and changes may be made without departing from the scope and spirit of the present invention, provided that the person has ordinary knowledge in the technical field of the present invention. It is obvious that it is possible.

Claims (12)

(A) pretreating the zeolite with moisture at a high temperature;
(B) a step of supporting iron ions with a precursor material solution of iron ions on the zeolite pretreated in the step (A) or on the zeolite not subjected to the step (A) and not pretreated;
(C) filtering the zeolite particles carrying iron ions in the step (B) and drying them;
(D) repeating steps (B) and (C) to increase the iron content of the powder dried in step (C);
(E) calcining the catalyst produced in step (D) in air;
(F) treating the catalyst obtained through the step (E) from the zeolite not subjected to the step (A) with water at a high temperature;
A method for producing a zeolite catalyst on which iron ions are supported for reducing nitrous oxide alone or nitrous oxide and nitric oxide simultaneously with an ammonia reducing agent characterized in that In the step (A),
The zeolite includes any of BEA, MFI, MOR and FER,
The zeolite has an Al ₂ O ₃ / SiO ₂ molar ratio of 5 to 100,
The zeolite contains a cation of any one of sodium, ammonium and hydrogen for reducing nitrous oxide alone or nitrous oxide and nitric oxide simultaneously with an ammonia reducing agent according to claim 1. A method for producing a zeolite catalyst carrying iron ions. The zeolite is subjected to moisture treatment by heating the zeolite at 400 to 600 ° C and then supplying 0.1 to 5 times the moisture of the zeolite in a nitrogen atmosphere for 0.1 to 2 hours. A method for producing a zeolite catalyst supporting iron ions for reducing nitrous oxide alone or nitrous oxide and nitric oxide simultaneously with the ammonia reducing agent according to Item 2. The step (B) uses iron nitrate hydrate (Fe (NO ₃ ) ₃ .9H ₂ O) as a precursor material of iron ions to adjust the concentration to 0.001 to 1.0 molar. A method for producing a zeolite catalyst carrying iron ions for reducing nitrous oxide alone or nitrous oxide and nitric oxide simultaneously with the ammonia reducing agent according to claim 1. Zeolite that has been subjected to moisture treatment in the step (A) or zeolite that has not passed the step (A) is added to the solution of the iron ion precursor material at a weight ratio of 0.1 to 3.0, and 10 to 35 ° C. The zeolite catalyst carrying iron ions for reducing nitrous oxide alone or nitrous oxide and nitric oxide at the same time by the ammonia reducing agent according to claim 4, characterized by being stirred for 5 to 30 hours Method. In the step (C), the cake obtained by filtering the zeolite slurry obtained in the step (B) is washed with 500 to 2000 ml of deionized distilled water, and the washed zeolite loaded with iron ions is washed with air. It is dried at 100 to 120 ° C for 5 to 24 hours. The ammonia reducing agent according to claim 1 carries nitrous oxide alone or iron ions for simultaneously reducing nitrous oxide and nitric oxide. Method for producing a zeolite catalyst. In the step (D), the step (B) and the step (C) are repeated 2 to 5 times. Nitrous oxide alone or nitrous oxide and monoxide with an ammonia reducing agent according to claim 1. A method for producing a zeolite catalyst carrying iron ions for simultaneously reducing nitrogen. In the step (E), the zeolite obtained in the step (D) is calcined in air at 400 to 600 ° C. for 1 to 5 hours. The nitrous oxide by the ammonia reducing agent according to claim 1, A method for producing a zeolite catalyst on which iron ions are supported for reducing nitrous oxide and nitric oxide simultaneously. In the step (F), the iron ions obtained through the step (B), the step (C), the step (D), and the step (E) are supported from the zeolite not subjected to the step (A). 2. After heating at 400 to 600 ° C. with respect to the zeolite, 0.1 to 5 times as much water as the zeolite weight is supplied in a nitrogen atmosphere for 0.5 to 2 hours. For producing a zeolite catalyst carrying iron ions for reducing nitrous oxide alone or nitrous oxide and nitric oxide simultaneously with an ammonia reducing agent. Produced by the method for producing a zeolite catalyst according to any one of claims 1 to 9,
The zeolite loaded with iron ions is activated and configured to reduce 70-100% nitrous oxide alone or both nitrous oxide and nitric oxide simultaneously at 300-400 ° C with an ammonia reducing agent. Zeolite catalyst carrying iron ions for reducing nitrous oxide alone or nitrous oxide and nitric oxide simultaneously with an ammonia reducing agent characterized by 10. Zeolite catalyst on which iron ions supported by nitrous oxide alone or simultaneously supplied with nitrous oxide and nitric oxide and produced by the method for producing a zeolite catalyst according to any one of claims 1 to 9 are supported. Nitrous oxide alone or nitrous oxide and nitric oxide are simultaneously reduced at a low catalytic reaction temperature and reduced by an ammonia reducing agent. A method of reducing nitric oxide. The catalytic reaction temperature at the time of reduction of the nitrous oxide and nitric oxide is a low temperature of 300 to 500 ° C. The ammonia reducing agent according to claim 11, wherein nitrous oxide or nitrous oxide and monoxide are used. A method of reducing nitrogen.

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