阅读说明：本技术 铁柱撑蒙脱石负载Mn-Ce-Sm复合催化剂的制备方法和应用 (Preparation method and application of iron pillared montmorillonite-loaded Mn-Ce-Sm composite catalyst ) 是由 叶青 王新鹏 孟繁伟 杨帆 于 2021-08-17 设计创作，主要内容包括：本发明提供了铁柱撑蒙脱石负载Mn-Ce-Sm复合催化剂的制备方法和应用。首先制备出具有较高比表面积的铁柱撑蒙脱石载体,然后通过硝酸锰,硝酸铈,硝酸钐混合溶液与铁柱撑蒙脱石旋转蒸发法制备出铁柱撑蒙脱石负载的Mn-Ce-Sm复合催化剂,其中Mn负载量≤4wt％,Ce负载量≤5wt％,Sm负载量≤0.5wt％。本发明所制催化剂在较宽的温度(150℃～400℃)范围内,对高空速、高O-(2)浓度、高H-(2)O含量和高浓度NO污染物具有较高的催化消除效果(NO转化率37％～92％)。并且该催化剂在低浓度SO-(2)的条件下,仍能保持较高的NO的转化率。本发明制备原料廉价且制备过程简单。(The invention provides a preparation method and application of an iron pillared montmorillonite-loaded Mn-Ce-Sm composite catalyst. Firstly preparing an iron pillared montmorillonite carrier with a higher specific surface area, and then preparing the iron pillared montmorillonite-loaded Mn-Ce-Sm composite catalyst by using a manganese nitrate, cerium nitrate and samarium nitrate mixed solution and an iron pillared montmorillonite rotary evaporation method, wherein the Mn loading capacity is less than or equal to 4 wt%, the Ce loading capacity is less than or equal to 5 wt%, and the Sm loading capacity is less than or equal to 0.5 wt%. The catalyst prepared by the invention has wide temperature range (150-400 ℃), high space velocity and high O 2 High concentration, high H 2 The O content and the high-concentration NO pollutants have higher catalytic elimination effect (the NO conversion rate is 37-92%). And the catalysisAgent at low concentration SO 2 Under the conditions of (1), the conversion rate of NO can still be kept high. The invention has cheap raw materials and simple preparation process.)

1. The preparation method of the iron pillared montmorillonite loaded Mn-Ce-Sm composite catalyst is characterized by comprising the following steps of:

(1) preparation of iron pillared montmorillonite carrier

Mixing natural montmorillonite with 1.2-1.8 mol/L H₂SO₄Stirring the solution for 4-6 hours in water bath at the temperature of 60-70 ℃, wherein the montmorillonite and the H₂SO₄The ratio of the solution was 1 g: 10ml of acidified montmorillonite is filtered and washed to be free of SO₄ ^2-Until now, with BaCl₂Inspecting the solution, drying the filtered sample in a drying oven for 6 hours at 120 ℃, and grinding the dried sample and sieving the ground sample with a 80-mesh sieve to obtain acid modified montmorillonite;

0.1 to 0.3mol/L Fe (NO) is added₃)₃An aqueous solution, 0.1-0.3 mol/L NaOH solution is slowly added dropwise into the solution at a speed of 1mL/min, [ OH ]^-]/[Fe³⁺]Keeping the temperature at 20-30 ℃ for 1-3 (molar ratio), then stirring for 9-12 hours, and aging the obtained suspension at room temperature for 12-24 hours to obtain iron pillared liquid;

adding the acidified modified montmorillonite into deionized water according to a certain proportion to prepare acidified montmorillonite suspension slurry, wherein the acidified montmorillonite suspension slurry comprises the following components in percentage by weight: deionized water (mass ratio) 1: 40-80 parts; dripping the iron pillared solution into the acidified montmorillonite suspension slurry, wherein [ Fe³⁺]: 4-10 mmol of acidified montmorillonite: 1g, stirring for 10-16 hours at the temperature of 20-30 ℃, aging for 12-24 hours at room temperature, drying, grinding and sieving at 100-120 ℃, then putting the mixture into a muffle furnace, raising the temperature to 300-450 ℃ at the rate of 1-2 ℃/min, and calcining at the temperatureBurning for 1-4 hours to obtain a sample which is iron pillared montmorillonite;

(2) preparation of Mn-Ce-Sm loaded iron pillared montmorillonite by rotary evaporation method

Adding the prepared iron pillared montmorillonite into a mixed solution of 0.019 mol/L-0.021 mol/L manganese nitrate, 0.019 mol/L-0.021 mol/L cerium nitrate and 0.019 mol/L-0.021 mol/L samarium nitrate, and stirring at 60-75 ℃ for 1-4 h, wherein the ratio of the iron pillared montmorillonite to the manganese nitrate is 100 g: 0.020 mol-0.040 mol, the proportion of the iron pillared montmorillonite to the cerium nitrate is 100 g: 0.030 mol-0.050 mol, the proportion of the iron pillared montmorillonite to the samarium nitrate is 100 g: 0.003mol to 0.005mol, rotary evaporation to dryness, drying at 100 ℃ to 120 ℃ for 12 h to 24h, and roasting at 450 ℃ for 1h to 4h to prepare the Mn-Ce-Sm/Fe-PILC composite catalyst.

2. Use of the catalyst of claim 1 for eliminating NO, wherein: the application of the supported Mn-Ce-Sm/Fe-PILC catalyst in eliminating NO is characterized in that: putting the catalyst into a continuous flow fixed bed device and introducing NH containing 330 ppm-1100 ppm₃、300ppm～1000ppm NO、5vl.％～10vl.％O₂And 1 vl.% to 10 vl.% H₂Reacting in O mixed gas, wherein the rest gas of the mixed gas is nitrogen, the reaction pressure is normal pressure 1atm, and the reaction space velocity is 10,000h^-1～100,000h^-1The reaction temperature is 150-450 ℃.

Technical Field

The invention relates to a preparation method of an iron pillared montmorillonite loaded Mn-Ce-Sm composite catalyst for catalytically eliminating NO and application thereof in selective catalytic elimination of NO.

Background

In recent years, with the rapid increase of the economy of our country, the demand for energy is increasing day by day, and the development and utilization of a large amount of fossil energy, the emission of waste gas generated by the combustion of the fossil energy poses a serious threat to the environment of our country, and nitrogen oxide (NOx) is one of the main components of the waste gas. Common nitrogen oxides include compounds in six valence states, such as dinitrogen monoxide (N)₂O), Nitric Oxide (NO), nitrogen dioxide (NO)₂) Dinitrogen trioxide (N)₂O₃) Dinitrogen tetroxide (N)₂O₄) And dinitrogen pentoxide (N)₂O₅) Etc., wherein the greatest proportion is NO. The accumulation of nitrogen oxides can cause serious environmental problems and can create direct hazards to human health. Under the combined action of nitrogen oxide and sulfur-containing compound, abnormal weather such as acid rain and chemical smog can be formed. The nitrogen oxides are combined with water vapor in the air to form acidic droplets, and the acidic droplets fall to the ground to become acid rain. Acid rain is corrosive and can have a great impact on human production and life as well as on the survival of other animals and plants. Nitrogen oxides and hydrocarbons in the atmosphere are irradiated by ultraviolet rays, and then undergo photochemical reaction to form toxic smoke, called photochemical smoke, which can seriously reduce atmospheric visibility and harm the respiratory system of a human body. In addition, nitrogen oxides floating in the atmosphere can react with ozone in the stratosphere, so that the ozone balance is broken, the ozone layer is consumed, and the human beings, animals and plants and even the whole earth are destructively damaged. Therefore, the problem of emission of nitrogen oxides is suddenly changed into one of important factors which influence the current social harmony, restrict the economic development and destroy the human survival, and the control and treatment of nitrogen oxides are the current research hotspots. At present, there are various methods for eliminating nitrogen oxides at home and abroad, wherein NH₃The method for selectively catalyzing and reducing the nitrogen oxide is mature, and is applied to the treatment of the pollution of the nitrogen oxide of automobile exhaust and thermal power plants. NH (NH)₃The SCR catalytic material mainly comprises a noble metal catalyst, a metal oxide catalyst, a molecular sieve catalyst and other catalytic materialsMaterial 4 systems, in which V₂O₅-WO₃(MoO₃)/TiO₂The system is most widely used, and is commercialized at present, but V₂O₅-WO₃(MoO₃)/TiO₂The catalytic system has the problems of insufficient low-temperature activity, secondary pollution caused by volatilization of high-temperature vanadium and the like.

In recent years, pillared clay (PILC) has become a focus of social research due to its characteristics of low economic cost, low energy consumption, low environmental load, and low possibility of generating secondary pollution in flue gas denitration. In addition, the pillared clay has NH₃Basic conditions required for the SCR reaction: the pillared clay has good thermal stability, and the sintering problem of the catalyst is avoided; the large specific surface area and the proper pore structure are favorable for the adsorption and reaction of reactants; provide a large number of acid sites, and is prone to NH₃And adsorption of NO and formation of active species, thereby promoting the catalytic reaction. Due to the excellent catalytic performance of the pillared clay, the pillared clay is widely applied to the catalytic fields of coal chemical industry, petroleum processing, fine chemical industry and the like at present. The Fe-PILC supported Mn-Ce-Sm composite catalyst is prepared by using iron pillared montmorillonite as a carrier through a rotary evaporation method, and high catalytic elimination of NO and sulfur resistance in a wide temperature range (150-400 ℃) are obtained. According to the literature reported at present, although other montmorillonite materials also have better activity, most of the catalysts prepared by using the supported single element have narrower reaction temperature and poorer activity, and the Mn-Ce-Sm/Fe-PILC catalyst prepared by the patent has better activity in a wider temperature range. The implementation of this project resulted in: national science foundation project (number: 21277008; 20777005); beijing Natural science Foundation (number: 8082008); the subsidization of the national emphasis research and development program (No.2017YFC0209905) is also the research content of these projects.

Disclosure of Invention

The invention aims to provide a preparation method of an iron pillared montmorillonite supported Mn, Ce and Sm composite catalyst and application of the iron pillared montmorillonite supported Mn, Ce and Sm composite catalyst in catalytic elimination of NO pollutants. The BET specific surface area volume of montmorillonite was 46m²Iron column support cover loaded by/g, Mn-Ce-SmThe BET specific surface area of montmorillonite is increased to 144m²(ii) in terms of/g. The provided catalyst can efficiently eliminate NO (37-92% NO conversion rate) in a wider temperature range (150-400 ℃). Moreover, the catalyst has higher sulfur resistance. The catalyst has simple preparation process and wide natural material.

The invention aims to provide a preparation method of an iron pillared montmorillonite supported Mn, Ce and Sm composite catalyst, which comprises the following steps:

(1) mixing natural montmorillonite with 1.2-1.8 mol/L H₂SO₄Stirring the solution for 4-6 hours in water bath at the temperature of 60-70 ℃, wherein the montmorillonite and the H₂SO₄The ratio of the solution was 1 g: 10ml of acidified montmorillonite is filtered and washed to be free of SO₄ ^2-Till now (with BaCl)₂Solution inspection), drying the filtered sample in a drying oven for 6 hours at 120 ℃, and grinding the dried sample and sieving the ground sample with a 80-mesh sieve to obtain the acid modified montmorillonite. 0.1 to 0.3mol/L Fe (NO) is added₃)₃An aqueous solution, 0.1-0.3 mol/L NaOH solution is slowly added dropwise into the solution at a speed of 1mL/min, [ OH ]^-]/[Fe³⁺]Keeping the temperature at 20-30 ℃ for 1-3 (molar ratio), then stirring for 9-12 hours, and aging the obtained suspension at room temperature for 12-24 hours to obtain the iron pillared liquid. Adding the acidified modified montmorillonite into deionized water according to a certain proportion to prepare acidified montmorillonite suspension slurry, wherein the acidified montmorillonite suspension slurry comprises the following components in percentage by weight: deionized water (mass ratio) 1: 40-80. Dripping the iron pillared solution into the acidified montmorillonite suspension slurry, wherein [ Fe³⁺]: 4-10 mmol of acidified montmorillonite: 1g, stirring for 10-16 hours at a temperature of 20-30 ℃, aging for 12-24 hours at room temperature, drying, grinding and sieving at 100-120 ℃, then putting the mixture into a muffle furnace, raising the temperature to 300-450 ℃ at a heating rate of 1-2 ℃/min, and calcining for 1-4 hours at the temperature, wherein the obtained sample is iron pillared montmorillonite. Adding the prepared iron pillared montmorillonite into a mixed solution of 0.019 mol/L-0.021 mol/L manganese nitrate, 0.019 mol/L-0.021 mol/L cerium nitrate and 0.019 mol/L-0.021 mol/L samarium nitrate, and stirring at 60-75 ℃ for 1-4 h, wherein the loading capacity of Mn is 2-4 wt%, the loading capacity of Ce is 3-5 wt%, and the loading capacity of Sm is 2-4 wt%And (3) evaporating the mixture to dryness by 0.3-0.5 wt% in a rotary manner, drying the mixture for 12-24 h at the temperature of 100-120 ℃, and roasting the mixture for 1-4 h at the temperature of 400 ℃ to prepare the supported Mn/Fe-PILC, Ce/Fe-PILC, Sm/Fe-PILC and Mn-Ce-Sm/Fe-PILC composite catalyst.

(2) The catalyst of the invention is prepared under the reaction pressure of normal pressure and 1atm and the high space velocity (10,000 h)^-1～100,000h^-1)、O₂Concentration (5-10 vl.%), H₂O content (1-10 vl.%), NH₃The concentration (330 ppm-1100 ppm), the NO concentration (300 ppm-1000 ppm) and the balance gas are N₂Under the condition, the catalyst has high catalytic activity (NO conversion rate is 37-92%) in a wide temperature range (150-400 ℃); at the reaction pressure of normal pressure and 1atm and high space velocity (10,000 h)^-1～100,000h^-1)、O₂Concentration (5-10 vl.%), H₂O content (1-10 vl.%), NH₃Concentration (330 ppm-1100 ppm), NO concentration (300 ppm-1000 ppm), SO₂The concentration (100 ppm-250 ppm) and the balance gas are N₂Under the condition, the supported Mn-Ce-Sm/Fe-PILC catalyst is considered to have SO in a wider temperature range (150-400℃)₂The NO conversion at time, at the temperature range studied, still maintained the catalytic activity at a high level, showing a high sulfur resistance.

Drawings

FIG. 1 is an XRD pattern of Mn/Fe-PILC, Mn-Ce-Sm/Fe-PILC-I, Mn-Ce-Sm/Fe-PILC-II, Mn-Ce-Sm/Fe-PILC-III catalysts prepared in examples 1, 2, 3 and 4 of the present invention.

FIG. 2 shows N-of Mn/Fe-PILC, Mn-Ce-Sm/Fe-PILC-I, Mn-Ce-Sm/Fe-PILC-II, Mn-Ce-Sm/Fe-PILC-III catalysts prepared in examples 1, 2, 3 and 4 of the present invention₂Adsorption/desorption scheme.

FIG. 3 is a graph of NH on Mn/Fe-PILC, Mn-Ce-Sm/Fe-PILC-I, Mn-Ce-Sm/Fe-PILC-II, Mn-Ce-Sm/Fe-PILC-III catalysts prepared in examples 1, 2, 3 and 4 of the present invention₃Selective catalytic reduction of NO activity.

FIG. 4 shows NH in the presence of sulfur in Mn/Fe-PILC, Mn-Ce-Sm/Fe-PILC-I, Mn-Ce-Sm/Fe-PILC-II, Mn-Ce-Sm/Fe-PILC-III catalysts prepared in examples 1, 2, 3 and 4 of the present invention₃Selective catalytic reduction of NO activity.

Detailed Description

Example 1

(1) Mixing natural montmorillonite with 1.2mol/L H₂SO₄Stirring the solution in water bath at 60 deg.C for 4 hr, wherein the montmorillonite is mixed with H₂SO₄The ratio of the solution was 1 g: 10ml of acidified montmorillonite is filtered and washed to be free of SO₄ ^2-Till now (with BaCl)₂Solution inspection), drying the filtered sample in a drying oven for 6 hours at 120 ℃, and grinding the dried sample and sieving the ground sample with a 80-mesh sieve to obtain the acid modified montmorillonite. Preparing 0.1mol/L Fe (NO)₃)₃Solution, 0.1mol/L NaOH solution is maintained at [ OH ]^-]/[Fe³⁺](molar ratio): 1, was slowly added dropwise to the above solution at a rate of 1mL/min, the temperature was maintained at 20 ℃, followed by stirring for 9 hours, and the resulting suspension was aged at room temperature for 12 hours to obtain an iron pillared solution. Adding the acidified modified montmorillonite into deionized water according to a certain proportion to prepare acidified montmorillonite suspension slurry, wherein the acidified montmorillonite suspension slurry comprises the following components in percentage by weight: deionized water (mass ratio) 1: 40. dripping the iron pillared solution into the acidified montmorillonite suspension slurry, wherein [ Fe³⁺]: acidified montmorillonite ═ 4 mmol: 1g, keeping the temperature at 20 ℃, stirring for 10 hours, aging at room temperature for 12 hours, drying, grinding and sieving at 100 ℃, then putting the mixture into a muffle furnace, raising the temperature to 300 ℃ at the heating rate of 2 ℃/min, keeping the temperature, and calcining for 1 hour, wherein the obtained sample is Fe-PILC. Dissolving cerium nitrate in deionized water to prepare a cerium nitrate solution with the concentration of 0.019mol/L, calculating the mass ratio of cerium-loaded iron-pillared montmorillonite (Ce wt% ═ 5 wt%), adding the obtained cerium nitrate solution with the above concentration into 4g of the iron-pillared montmorillonite to prepare a slurry precursor, stirring at 60 ℃ for 1h, rotationally evaporating to dryness, drying at 100 ℃ for 12 h, and roasting at 400 ℃ for 1h to prepare the supported Ce/Fe-PILC composite catalyst.

(2) The catalyst of the invention has the reaction pressure of 1atm under normal pressure and the space velocity of 10,000h^-1、O₂Concentration 5 vl.%, H₂O content 1 vl.%, NH₃Concentration 330ppm, NO concentration 300ppm and N₂Under the condition of being used as equilibrium gas, has higher catalytic elimination within a wider temperature range (150 ℃ -400 ℃), has low catalytic eliminationConcentration NO activity (NO conversion rate 21% to 77%); the reaction pressure is 1atm under normal pressure and the space velocity is 10,000h^-1、O₂Concentration 5 vl.%, H₂O content 1 vl.%, NH₃330ppm NO concentration 300ppm SO₂Concentration 100ppm and N₂Under the condition of equilibrium gas, the Ce/Fe-PILC catalyst is considered, the NO conversion rate under the condition of sulfur is in the temperature range (150 ℃ -400 ℃), and the catalytic activity is still higher and the sulfur resistance is better under the temperature range studied.

Example 2

(1) Mixing natural montmorillonite with 1.4mol/L H₂SO₄The solution was stirred in a water bath at 63 ℃ for 4 hours, wherein the smectite was reacted with H₂SO₄The ratio of the solution was 1 g: 10ml of acidified montmorillonite is filtered and washed to be free of SO₄ ^2-Till now (with BaCl)₂Solution inspection), drying the filtered sample in a drying oven for 6 hours at 120 ℃, and grinding the dried sample and sieving the ground sample with a 80-mesh sieve to obtain the acid modified montmorillonite. Preparing 0.17mol/L Fe (NO)₃)₃Solution, 0.17mol/L NaOH solution is maintained as [ OH ]^-]/[Fe³⁺](molar ratio) 1.7 was slowly added dropwise to the above solution at a rate of 1mL/min, the temperature was maintained at 23 ℃, followed by stirring for 10 hours, and the resulting suspension was aged at room temperature for 16 hours to obtain an iron pillared solution. Adding the acidified modified montmorillonite into deionized water according to a certain proportion to prepare acidified montmorillonite suspension slurry, wherein the acidified montmorillonite suspension slurry comprises the following components in percentage by weight: deionized water (mass ratio) 1: 50. dripping the iron pillared solution into the acidified montmorillonite suspension slurry, wherein [ Fe³⁺]: acidified montmorillonite ═ 6 mmol: 1g, stirring for 12 hours while keeping the temperature at 23 ℃, aging for 16 hours at room temperature, drying, grinding and sieving at 110 ℃, then putting the mixture into a muffle furnace, raising the temperature to 350 ℃ at the heating rate of 2 ℃/min, keeping the temperature and calcining for 2 hours, and obtaining the sample Fe-PILC. Dissolving manganese nitrate, cerium nitrate and samarium nitrate in deionized water to prepare a solution with the concentration of 0.019mol/L manganese nitrate, 0.019mol/L cerium nitrate and 0.019mol/L samarium nitrate, and loading iron column-supported montmorillonite with manganese according to the mass ratio of (Mn wt% ═ 2 wt%), iron column-supported montmorillonite with cerium according to the mass ratio of (Ce wt% ═ 3 wt%), iron column-supported montmorillonite with samarium according to the mass ratio ofAdding manganese nitrate solution, cerium nitrate solution and samarium nitrate solution with the above concentrations into 4g of the iron pillared montmorillonite to prepare slurry-shaped precursor, stirring at 65 ℃ for 2h, rotating to evaporate and dry, drying at 105 ℃ for 14 h, and roasting at 400 ℃ for 2h to prepare the supported Mn-Ce-Sm/Fe-PILC-I composite catalyst.

(2) The catalyst of the invention has the reaction pressure of 1atm under normal pressure and the high space velocity of 40,000h^-1、O₂Concentration 6 vl.%, H₂O content 3 vl.%, NH₃A concentration of 550ppm, a NO concentration of 500ppm and N₂Under the condition of being used as equilibrium gas, the catalyst has high catalytic elimination activity (NO conversion rate is 32-84%) of low-concentration NO in a wide temperature range (150-400 ℃); under the reaction pressure of normal pressure and 1atm and high space velocity, 40,000h^-1、O₂Concentration 6 vl.%, H₂O content 3 vl.%, NH₃550ppm in concentration, 500ppm in concentration of NO, and SO₂Concentration 150ppm and N₂Under the condition of equilibrium gas, the Mn-Ce-Sm/Fe-PILC-I catalyst is considered, the NO conversion rate under the condition of sulfur is in the temperature range (150-400 ℃), and the catalytic activity is still higher and the sulfur resistance is better under the temperature range studied.

Example 3

(1) Mixing natural montmorillonite with 1.6mol/L H₂SO₄Stirring the solution at 66 deg.C in water bath for 5 hr, wherein the montmorillonite is mixed with H₂SO₄The ratio of the solution was 1 g: 10ml of acidified montmorillonite is filtered and washed to be free of SO₄ ^2-Till now (with BaCl)₂Solution inspection), drying the filtered sample in a drying oven for 6 hours at 120 ℃, and grinding the dried sample and sieving the ground sample with a 80-mesh sieve to obtain the acid modified montmorillonite. Preparing 0.24mol/L Fe (NO)₃)₃Solution, 0.24mol/L NaOH solution is kept [ OH ]^-]/[Fe³⁺](molar ratio) 2.4, the solution was slowly added dropwise at a rate of 1mL/min, the temperature was maintained at 26 ℃ and then stirred for 11 hours, and the resulting suspension was aged at room temperature for 20 hours to obtain an iron pillared solution. Adding the acidified modified montmorillonite into deionized water according to a certain proportion to obtain acidified montmorillonite suspension slurryAnd (3) removing the clay: deionized water (mass ratio) 1: 60. dripping the iron pillared solution into the acidified montmorillonite suspension slurry, wherein [ Fe³⁺]: acidified montmorillonite ═ 8 mmol: 1g, stirring for 14 hours while keeping the temperature at 26 ℃, aging for 20 hours at room temperature, drying, grinding and sieving at 120 ℃, then putting the mixture into a muffle furnace, raising the temperature to 400 ℃ at the heating rate of 2 ℃/min, keeping the temperature and calcining for 3 hours, and obtaining the sample Fe-PILC. Dissolving manganese nitrate, cerium nitrate and samarium nitrate in deionized water to prepare manganese nitrate with the concentration of 0.020mol/L, cerium nitrate with the concentration of 0.020mol/L and samarium nitrate solution with the concentration of 0.020mol/L, manganese nitrate solution with the concentration of 0.020mol/L and samarium nitrate solution with the concentration of 0.020mol/L, cerium nitrate solution with the concentration of 3 wt% of manganese loaded iron pillared montmorillonite, manganese nitrate solution with the concentration of 4 wt% of cerium loaded iron pillared montmorillonite, samarium nitrate solution with the concentration of samarium loaded iron pillared montmorillonite with the mass ratio of samarium loaded iron pillared montmorillonite of 0.4 wt% of samarium loaded iron pillared montmorillonite, cerium nitrate solution and samarium nitrate solution are added into 4g of iron pillared montmorillonite to prepare slurry-shaped precursor, stirring the slurry-shaped precursor for 3h at 70 ℃, rotating and evaporating to dry the slurry-shaped precursor, drying the slurry for 16 h at 110 ℃, and roasting the slurry-shaped precursor for 3h at 400 ℃ to prepare the supported Mn-Ce-Sm/Fe-PILC-II composite catalyst.

(2) The catalyst of the invention has the reaction pressure of 1atm under normal pressure and the space velocity of 80,000h^-1、O₂Concentration 8 vl.%, H₂O content 6 vl.%, NH₃770ppm of NO, 700ppm of NO and N₂Under the condition of being used as equilibrium gas, the catalyst has higher catalytic elimination activity (NO conversion rate is 37-92%) of low-concentration NO within a wide temperature range (150-400 ℃); at the reaction pressure of normal pressure 1atm and space velocity of 80,000h^-1、O₂Concentration 8 vl.%, H₂O content 6 vl.%, NH₃770ppm of NO, 700ppm of SO₂Concentration 200ppm and N₂Under the condition of equilibrium gas, the Mn-Ce-Sm/Fe-PILC-II catalyst is considered, the NO conversion rate under the condition of sulfur is in the temperature range (150 ℃ -400 ℃), and the catalytic activity is still higher and the sulfur resistance is better under the temperature range studied.

Example 4

(1) Mixing natural montmorillonite with 1.8mol/L H₂SO₄Stirring the solution at 70 deg.C in water bath for 4 hr, wherein the montmorillonite is mixed with H₂SO₄Solutions ofIn a ratio of 1 g: 10ml of acidified montmorillonite is filtered and washed to be free of SO₄ ^2-Till now (with BaCl)₂Solution inspection), drying the filtered sample in a drying oven for 6 hours at 120 ℃, and grinding the dried sample and sieving the ground sample with a 80-mesh sieve to obtain the acid modified montmorillonite. Preparing 0.3mol/L Fe (NO)₃)₃Solution, 0.3mol/L NaOH solution is kept [ OH ]^-]/[Fe³⁺](molar ratio): 3, was slowly added dropwise to the above solution at a rate of 1mL/min, the temperature was maintained at 30 ℃, followed by stirring for 12 hours, and the resulting suspension was aged at room temperature for 24 hours to obtain an iron pillared solution. Adding the acidified modified montmorillonite into deionized water according to a certain proportion to prepare acidified montmorillonite suspension slurry, wherein the acidified montmorillonite suspension slurry comprises the following components in percentage by weight: deionized water (mass ratio) 1: 80. dripping the iron pillared solution into the acidified montmorillonite suspension slurry, wherein [ Fe³⁺]: acidified montmorillonite ═ 10 mmol: 1g, keeping the temperature at 30 ℃, stirring for 16 hours, aging for 24 hours at room temperature, drying, grinding and sieving at 120 ℃, then putting the mixture into a muffle furnace, raising the temperature to 450 ℃ at the heating rate of 2 ℃/min, keeping the temperature, and calcining for 4 hours to obtain the sample Fe-PILC. Dissolving manganese nitrate, cerium nitrate and samarium nitrate in deionized water to prepare manganese nitrate with the concentration of 0.020mol/L, cerium nitrate with the concentration of 0.020mol/L and samarium nitrate solution with the concentration of 0.020mol/L, manganese nitrate solution with the concentration of 0.020mol/L and samarium nitrate solution with the concentration of 0.020mol/L, cerium nitrate solution with the concentration of 4 wt% of manganese-loaded iron-pillared montmorillonite, manganese nitrate solution with the concentration of 4g of cerium-loaded iron-pillared montmorillonite (Ce wt% of 5 wt%), samarium-loaded iron-pillared montmorillonite solution with the mass ratio of 0.5 wt% of samarium-loaded iron-pillared montmorillonite, cerium nitrate solution and samarium nitrate solution are added into 4g of iron-pillared montmorillonite to prepare a slurry precursor, stirring the slurry precursor for 4h at the temperature of 75 ℃, rotating and evaporating the slurry to dry the slurry for 24h at the temperature of 120 ℃, and roasting the slurry for 4h at the temperature of 400 ℃ to prepare the supported Mn-Ce-Sm/Fe-PILC-III composite catalyst.

(2) The catalyst of the invention has the reaction pressure of 1atm under normal pressure and the space velocity of 100,000h^-1、O₂Concentration 10 vl.%, H₂O content 10 vl.%, NH₃1100ppm in concentration, 1000ppm in NO concentration and N₂Under the condition of being used as equilibrium gas, the catalyst has higher catalytic elimination activity (NO conversion rate is 35-90%) of low-concentration NO in a lower temperature range (150-400 ℃);the reaction pressure is 1atm under normal pressure and the space velocity is 100,000h^-1、O₂Concentration 10 vl.%, H₂O content 10 vl.%, NH₃1100ppm NO concentration, 1000ppm NO concentration, SO₂Concentration 250ppm and N₂Under the condition of equilibrium gas, the Mn-Ce-Sm/Fe-PILC-III catalyst is considered, the NO conversion rate under the condition of sulfur is in the temperature range (150-400 ℃), and the catalytic activity is still higher and the sulfur resistance is better under the temperature range studied.