A nanometer spherical low-temperature rare earth-based denitration and carbon monoxide removal catalyst, a preparation method and application thereof

Abstract

The application discloses a nanometer spherical low-temperature rare earth-based denitration and carbon monoxide removal catalyst and a preparation method and application thereof. The catalyst takes alumina as a carrier, takes a composite oxide of manganese dioxide and cerium dioxide as an active component, and takes iron oxide as a cocatalyst. The catalyst synthesized by the method has the advantages of a large specific surface area, sufficient exposure of active sites and nanometer limitation, and can realize the denitration and carbon monoxide removal targets of low-temperature flue gas working conditions of non-electricity industries such as steel and chemical industries.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method and application of a nanospherical low-temperature rare earth-based denitration and carbon monoxide removal catalyst, and belongs to the field of industrial flue gas purification. BACKGROUND

[0002] In the non-electricity industry, including the steel sintering industry, the chemical industry and the like, the concentration of NO x and CO in flue gas is relatively high, which requires that a catalyst under low-temperature conditions can effectively realize the combined removal of NO and CO. However, the catalysts in this field generally face common problems of performance and stability, which include insufficient low-temperature activity, weak resistance to poisoning, poor working condition adaptability and limited multi-pollutant synergistic removal capacity, thereby affecting the efficiency and stability of the catalyst in actual application.

[0003] With the improvement of environmental protection requirements, the flue gas treatment technology in the non-electricity industry is facing higher innovation and application challenges, especially in the low-temperature denitration and carbon monoxide removal technology. The existing catalysts cannot fully meet these requirements, and therefore, it is particularly important to develop new catalysts to cope with these challenges. Rare earth-based catalysts are considered as an important direction for the development of future denitration catalysts due to their non-toxicity, low cost and good low-temperature activity. In the SCR denitration technology, the flue gas treatment in the non-electricity industry also needs to cope with the challenges of high concentrations of SO2, alkali metals, alkaline earth metals and volatile organic compounds and the like, which have a significant impact on the performance of the catalyst. Therefore, improving the low-temperature activity, resistance to sulfur and ammonium salt poisoning and resistance to alkali metal poisoning of the catalyst, and enhancing the synergistic removal performance of NO x and CO, become key targets for the development of future SCR catalysts. Considering the technical difficulty and high investment cost of flue gas treatment in the non-electricity industry, the development of a low-temperature catalyst capable of simultaneously removing denitration and CO becomes an important research direction in the field. SUMMARY

[0004] The application aims at the insufficient catalytic activity of the existing low-temperature denitration and carbon monoxide removal catalysts for flue gas in the non-electricity industry and existing problems, and proposes a preparation method and application of a nanospherical low-temperature rare earth-based denitration and carbon monoxide removal catalyst.

[0005] The nanometer spherical low-temperature rare earth-based denitration and carbon monoxide removal catalyst is characterized in that the catalyst is prepared by using alumina as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a catalyst promoter, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent by means of high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method; wherein, based on the mass of the carrier, the mass percentage of the active component is 5-10%, and the mass percentage of the catalyst promoter is 5-10%; the mass ratio of manganese dioxide to cerium dioxide in the active component is 1:(0.5-2); and the catalyst is prepared by the following method:

[0006] (1) High-temperature hydrothermal method for preparing alumina nanosphere carrier

[0007] The aluminum salt, ammonia water, p-hydroxybenzoic acid, deionized water and ethanol are uniformly mixed, and then placed in a hydrothermal reactor for high-temperature hydrothermal reaction; after the reaction is completed, the alumina nanosphere carrier is obtained by filtration and drying.

[0008] (2) Incomplete inverse emulsion polymerization method for growing polyacrylamide

[0009] The monomer acrylamide, initiator, buffer solution and alumina nanosphere carrier prepared in step (1) are uniformly mixed to obtain an aqueous phase and continuously stirred; then, n-hexane and emulsifier are uniformly mixed to obtain an oil phase; the oil phase is added dropwise into the aqueous phase and continuously stirred to form an inverse emulsion; then, the inverse emulsion is first placed in an oil bath for oil bath reaction, and then placed in an ice bath for low-temperature reaction; after that, the inverse emulsion is again placed in an oil bath for oil bath reaction, and then placed in an ice bath for low-temperature reaction; finally, the inverse emulsion is washed with deionized water and ethanol for three times to obtain the alumina nanosphere carrier with grown polyacrylamide.

[0010] (3) Impregnation loading method for growing active component and catalyst promoter

[0011] The manganese salt, cerium salt and iron salt are uniformly mixed to obtain a composite precursor solution; then, the alumina nanosphere carrier with grown polyacrylamide obtained in step (2) is placed in the composite precursor solution; the mixed solution is dried in an oven; and finally, the nanometer spherical low-temperature rare earth-based denitration and carbon monoxide removal catalyst is obtained by calcining in a muffle furnace.

[0012] In the technical scheme of the present application, the aluminum salt in step (1) is aluminum nitrate or aluminum chloride; the ammonia water is an ammonia water solution with a mass fraction of 15-20%; and the mass ratio of the aluminum salt, ammonia water, p-hydroxybenzoic acid, deionized water and ethanol is 1:(3-5):(0.1-0.2):(30-60):(40-80).

[0013] The high-temperature hydrothermal reaction in step (1) has a temperature of 160-180 DEG C, a time of 3-6 hours, a drying temperature of 80-100 DEG C, and a drying time of 6-12 hours.

[0014] In the technical scheme of the present application: the initiator in step (2) is ammonium persulfate, the buffer solution is a sodium phosphate solution with a mass fraction of 10-20%, the mass ratio of acrylamide monomer, initiator, buffer solution and alumina nanosphere carrier is 1:(0.01-0.03):(10-20):(20-30), and the rate of continuous stirring is 100-200 r / min.

[0015] In the technical scheme of the present application: the emulsifier in step (2) is a fatty alcohol, the mass ratio of acrylamide monomer, n-hexane and emulsifier is 1:(20-40):(0.05-0.10), the oil bath reaction temperature is 50-70 DEG C, and the oil bath reaction time is 20-30 min.

[0016] In the technical scheme of the present application: the manganese salt in step (3) is manganese chloride or manganese nitrate hexahydrate, the cerium salt is cerium chloride or cerium nitrate hexahydrate, the iron salt is ferric chloride hexahydrate or ferric nitrate nonahydrate, and the mass ratio of manganese salt and deionized water is 1:(30-50).

[0017] In the technical scheme of the present application: the drying temperature in step (3) is 80-100 DEG C, the drying time is 6-12 hours, the calcination temperature is 500-600 DEG C, and the calcination time is 3-6 hours.

[0018] In the technical scheme of the present application, the above-mentioned catalyst preparation method is applied to the denitration and decarburization of low-temperature flue gas in non-electricity industries.

[0019] The catalyst activity evaluation experiment conditions of the present application are as follows: 1 mL of catalyst with a mesh size of 20-40 is poured into a quartz tube with an inner diameter of 6 mm, fixed by quartz wool and iron wire, placed in a tube furnace, and the actual temperature of the catalytic reaction is adjusted by controlling the heating temperature of the tube furnace. The gas inlet components are NO (500 ppm), NH3 (500 ppm), O2 (11 vol.%), CO (1000 ppm), and the rest is N2, the total gas flow is 500 mL / min, the control temperature is 90-210 DEG C, each temperature interval stays stable for 30 min, the NO and CO concentrations are measured by Laoying 3021 type portable carbon emission monitor, and the denitration and decarburization efficiency of the catalyst is higher than 90% in the temperature interval of 150-210 DEG C.

[0020] Beneficial effects:

[0021] (1) In the present application, p-hydroxybenzoic acid is used as a morphology control agent to form uniform nanospheres of alumina, and in order to enable the active component to grow uniformly on the surface of the carrier and to fully contact the reaction gas molecules, polyacrylamide is grown on the surface of the alumina nanospheres by using an incomplete inverse emulsion polymerization method, and then the steric hindrance effect is used to enable the active component and the promoter component to grow on the surface of the alumina nanospheres and to ensure that they do not agglomerate on the surface of the alumina nanospheres, and finally the active component and the promoter component are grown on the surface of the alumina nanospheres like a needle thread, so that the active component and the promoter component can be fully exposed and can maximize the contact with the reaction molecules, thereby improving the low-temperature denitration activity and the low-temperature carbon monoxide removal activity;

[0022] (2) The conventional inverse emulsion polymerization method causes the polyacrylamide to grow uniformly on the surface of the alumina carrier, and no steric hindrance effect is formed, so it is necessary to place the polyacrylamide in an ice bath during the reaction to reduce the reaction temperature and slow down the reaction rate, and the process is repeated, so that the polyacrylamide cannot completely cover the surface of the alumina, i.e., space is left for the growth of the active component and the promoter component;

[0023] (3) In the present application, the active component and the promoter component are impregnated and loaded on the surface of the alumina nanospheres and in the space of the polyacrylamide by using the steric hindrance effect, and then the polyacrylamide is removed by high-temperature calcination, so that the precursors can be converted into oxides, and the reducing atmosphere formed by the polyacrylamide during calcination can improve the concentration of oxygen vacancies on the surface of the catalyst, thereby further improving the low-temperature catalytic activity;

[0024] (4) In the present application, alumina is used as the carrier, manganese oxide and cerium oxide are used as the active component, and iron oxide is used as the promoter, so that the catalyst not only has the mechanical strength and surface acidity of alumina, but also has the excellent redox performance and oxygen storage and release performance of manganese oxide and cerium oxide, and also has the abundant acid sites of iron oxide, thereby ensuring its low-temperature denitration and carbon monoxide removal performance.

[0025] Therefore, the catalyst prepared in the present application not only has excellent low-temperature flue gas denitration and carbon monoxide removal performance, but also has the advantages of environmental friendliness, simple preparation process, low cost, high cost performance, and strong application and promotion value. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 TEM image of the carrier prepared in Example 1;

[0027] Figure 2 TEM image of the catalyst prepared in Example 1;

[0028] Figure 3 NO removal performance diagram of the catalyst prepared in Examples 1-3 and Comparative Examples 1-2;

[0029] Figure 4 Figure 1 is a graph showing the CO removal performance of the catalysts prepared in Examples 1-3 and Comparative Examples 1-2. DETAILED DESCRIPTION

[0030] The application will be further described in conjunction with the following examples, which are implemented on the premise of the technical solutions of the application, and detailed implementation modes and specific operation processes are given, but the protection scope of the application is not limited to the following examples.

[0031] Example 1

[0032] (1) Preparation of alumina nanosphere carrier by high-temperature hydrothermal method

[0033] 20.000 g of aluminum nitrate, 60.000 g of 15% ammonia water solution, 2.000 g of p-hydroxybenzoic acid, 600.000 g of deionized water and 800.000 g of ethanol were weighed and stirred uniformly, then placed in a hydrothermal reactor at 160°C for 3h hydrothermal reaction, after the reaction was completed, filtered and placed in an oven at 80°C for drying for 6h to obtain an alumina nanosphere carrier (TEM image of the carrier is shown in FIG. 1) ; Figure 1

[0034] (2) Growth of polyacrylamide by incomplete inverse emulsion polymerization method

[0035] 0.479 g of monomer acrylamide, 0.005 g of ammonium persulfate, 4.787 g of 10% sodium phosphate solution and 9.574 g of the alumina nanosphere carrier prepared in step (1) were weighed and mixed uniformly and placed in an open beaker, then the aqueous phase was obtained by continuously stirring the mixed solution at a stirring rate of 100 r / min at room temperature, 9.580 g of n-hexane and 0.024 g of fatty alcohol were then weighed and mixed uniformly in a beaker to obtain an oil phase, the oil phase was added dropwise into the continuously stirred aqueous phase to obtain an inverse emulsion solution, the inverse emulsion solution was first placed in a 50°C oil bath for 20 min, then placed in an ice bath for 30 min, then placed in a 50°C oil bath for 20 min, and finally placed in an ice bath for 30 min, after the reaction was completed, the alumina nanosphere carrier with grown polyacrylamide was obtained by washing with deionized water and ethanol for three times;

[0036] (3) Growth of active component and promoter by impregnation loading method

[0037] ​A precursor solution was prepared by mixing 0.485 g of manganese chloride, 0.240 g of cerium chloride, 0.851 g of iron chloride hexahydrate and 25.542 g of deionized water, and then the polyacrylamide-grown alumina nanospheres support prepared in step (2) was mixed and impregnated with the precursor solution prepared in step (3), and was placed in an oven for drying at 80°C for 6 h, and after drying, was calcined at a high temperature of 500°C for 3 h to prepare a catalyst (the mass percentage of the active component was 5%, and the mass percentage of the promoter was 5%, the mass ratio of manganese dioxide to cerium dioxide in the active component was 1:0.5, and the TEM image of the catalyst is shown in Figure 2 ;

[0038] (4) Test of catalytic activity

[0039] 1 mL of the catalyst with a mesh size of 20-40 was poured into a quartz tube with an inner diameter of 6 mm, and was fixed with quartz wool and an iron wire mesh, and the quartz tube was placed in a tube furnace, and the actual temperature of the catalytic reaction was adjusted by controlling the heating temperature of the tube furnace. The gas components were: NO (500 ppm), NH3(500 ppm), O2(11 vol.%), CO (1000 ppm), and the rest was N2, and the total flow rate of the gas was 500 mL / min, and the temperature was controlled at 90-210°C, and each temperature was kept stable for 30 min, and the concentrations of NO and CO were measured by using a Laoyang 3021 type portable carbon emission monitor, and the denitration and decarbonization efficiency of the catalyst was higher than 90% in the temperature range of 150-210°C.

[0040] Example 2

[0041] (1) Preparation of an alumina nanosphere support by a high-temperature hydrothermal method

[0042] 20.000 g of aluminum nitrate, 100.000 g of 20% ammonia water solution, 4.000 g of p-hydroxybenzoic acid, 1200.000 g of deionized water and 1600.000 g of ethanol were mixed and stirred uniformly, and then were placed in a hydrothermal reaction kettle for hydrothermal reaction at 180°C for 6 h, and after the reaction was completed, were filtered and dried in an oven at 100°C for 12 h to obtain an alumina nanosphere support;

[0043] (2) Growth of polyacrylamide by an incomplete inverse emulsion polymerization method

[0044] Take 0.319 g of acrylamide monomer, 0.010 g of ammonium persulfate, 6.383 g of 20% sodium phosphate solution and 9.574 g of alumina nanosphere carrier prepared in step (1) and mix them uniformly, and then place them in an open beaker, and then continuously stir the mixed solution at a stirring rate of 200 r / min at room temperature to obtain an aqueous phase, and then take 12.765 g of n-hexane and 0.032 g of fatty alcohol and mix them uniformly in a beaker to obtain an oil phase, and then drop the oil phase into the continuously stirred aqueous phase to obtain an inverse emulsion solution, and then first place the inverse emulsion solution in a 70°C oil bath for 30 min, and then place the inverse emulsion solution in an ice bath for 60 min, and then place the inverse emulsion solution in a 70°C oil bath for 30 min, and then place the inverse emulsion solution in an ice bath for 60 min, and then after the reaction is completed, wash the grown polyacrylamide alumina nanosphere carrier with deionized water and ethanol three times to obtain the grown polyacrylamide alumina nanosphere carrier;

[0045] (3) Impregnation loading method for growing active components and promoters

[0046] Take 1.089 g of manganese nitrate hexahydrate, 1.664 g of cerium nitrate hexahydrate, 2.503 g of ferric chloride hexahydrate and 125.141 g of deionized water and mix them uniformly to prepare a precursor solution, and then mix and impregnate the grown polyacrylamide alumina nanosphere carrier prepared in step (2) with the precursor solution prepared in step (3), and then place them in an oven for drying at 1000°C for 12 h, and then after drying, calcine them at a high temperature of 600°C for 6 h to obtain a catalyst (with the mass percentage of the active components being 10% and the mass percentage of the promoters being 10% based on the mass of the carrier, and the mass ratio of manganese dioxide to cerium dioxide in the active components being 1:2);

[0047] (4) Catalytic activity test

[0048] Take 1 mL of the catalyst with a particle size of 20-40 mesh, and pour it into a quartz tube with an inner diameter of 6 mm, and fix it with quartz wool and an iron mesh, and then place the quartz tube in a tube furnace, and adjust the actual temperature of the catalytic reaction by controlling the heating temperature of the tube furnace. The gas components are: NO (500 ppm), NH3 (500 ppm), O2 (11 vol.%), CO (1000 ppm), and the rest is N2, and the total gas flow is 500 mL / min, and the control temperature is 90-210°C, and each temperature interval of 30°C stays stable for 30 min, and the concentrations of NO and CO are measured by using a Laoyang 3021 type portable carbon emission monitor, and the denitration and decarburization efficiency of the catalyst is higher than 90% in the temperature interval of 150-210°C.

[0049] Example 3

[0050] (1) Preparation of alumina nanosphere carrier by high-temperature hydrothermal method

[0051] Take 20.000 g of aluminum nitrate, 80.000 g of 18% ammonia solution, 3.000 g of p-hydroxy benzoic acid, 900.000 g of deionized water and 1200.000 g of ethanol, mix and stir uniformly, then put into the hydrothermal reactor at 170℃ for 5h, after reaction, filter and dry in the oven at 90℃ for 10h to get the alumina nanosphere carrier;

[0052] (2) Growth of polyacrylamide by incomplete inverse emulsion polymerization

[0053] Take 0.383 g of acrylamide monomer, 0.008 g of ammonium persulfate, 5.745 g of 15% sodium phosphate solution and 9.574 g of alumina nanosphere carrier prepared in step (1) and mix uniformly, then put into an open beaker, then continuously stir the mixed solution at room temperature at a stirring rate of 180 r / min to get the water phase, then take 11.495 g of n-hexane and 0.031 g of fatty alcohol and mix uniformly in a beaker to get the oil phase, drop the oil phase into the continuously stirred water phase to get the inverse emulsion solution, first put the inverse emulsion solution into a 60℃ oil bath for 20 min, then put it into an ice bath for 40 min, then put it into a 60℃ oil bath for 20 min, and finally put it into an ice bath for 40 min, after reaction, wash with deionized water and ethanol three times to get the alumina nanosphere carrier with grown polyacrylamide;

[0054] (3) Growth of active components and promoters by impregnation loading method

[0055] Take 0.576 g of manganese chloride, 0.570 g of cerium chloride, 1.012 g of iron chloride hexahydrate and 40.478 g of deionized water and mix uniformly to prepare a precursor solution, then mix and impregnate the alumina nanosphere carrier with grown polyacrylamide prepared in step (2) with the precursor solution prepared in step (3), and dry in an oven at 90℃ for 10h, after drying, calcine at 550℃ for 5h to prepare the catalyst (the mass percentage content of active components is 8% and the mass percentage content of promoters is 6% based on the mass of the carrier, and the mass ratio of manganese dioxide to cerium dioxide in the active components is 1:1);

[0056] (4) Test of catalytic activity

[0057] Take 20-40 mesh catalyst 1 mL, pour into the inner diameter of 6 mm quartz tube, with quartz wool and iron wire fixed, the quartz tube is placed in the tube furnace, by controlling the heating temperature of the tube furnace to adjust the actual temperature of the catalytic reaction. The gas composition: NO (500 ppm), NH3(500 ppm), O2(11 vol.%), CO (1000 ppm) the rest is N2, the total flow rate of the gas is 500 mL / min, control temperature at 90-210℃, every 30℃ stay stable for 30 min, using Laoying 3021 type portable carbon emission monitor to determine the concentration of NO and CO, the catalyst denitration and decarburization efficiency is higher than 90% in 150-210℃ temperature range.

[0058] Comparative example 1

[0059] (1) Preparation of the carrier

[0060] Except that p-hydroxybenzoic acid is not used as a morphology control agent during catalyst preparation, other conditions are the same as example 1.

[0061] (2) Test of catalytic activity

[0062] Take 20-40 mesh catalyst 1 mL, pour into the inner diameter of 6 mm quartz tube, with quartz wool and iron wire fixed, the quartz tube is placed in the tube furnace, by controlling the heating temperature of the tube furnace to adjust the actual temperature of the catalytic reaction. The gas composition: NO (500 ppm), NH3(500 ppm), O2(11 vol.%), CO (1000 ppm) the rest is N2, the total flow rate of the gas is 500 mL / min, control temperature at 90-210℃, every 30℃ stay stable for 30 min, using Laoying 3021 type portable carbon emission monitor to determine the concentration of NO and CO, the catalyst denitration and decarburization efficiency is higher than 90% in 150-210℃ temperature range.

[0063] (3) Comparison effect

[0064] Compared with example 1, p-hydroxybenzoic acid is used as a morphology control agent during catalyst preparation, and the catalyst prepared is irregular nanoparticles, which reduces the proportion of active sites exposed, resulting in low temperature catalytic activity.

[0065] Comparative example 2

[0066] (1) Preparation of the catalyst

[0067] Except that the catalyst is not placed in an ice bath to reduce the reaction temperature and slow down the reaction rate during catalyst preparation, other conditions are the same as example 2.

[0068] (2) Test of catalytic activity

[0069] Take 20-40 mesh catalyst 1 mL, pour into the inner diameter of 6 mm quartz tube, with quartz wool and iron wire fixed, the quartz tube is placed in the tube furnace, by controlling the heating temperature of the tube furnace to adjust the actual temperature of the catalytic reaction. The gas composition: NO (500 ppm), NH3(500 ppm), O2(11 vol.%), CO (1000 ppm) the rest is N2, the total gas flow is 500 mL / min, control temperature at 90-210℃, every 30℃ stop and stabilize for 30 min, using Laoying 3021 type portable carbon emission monitor to determine the concentration of NO and CO, the catalyst denitration efficiency is 53.3% at 150℃, the carbon monoxide removal efficiency is 63.1%;

[0070] (3)Comparative effect

[0071] Compared with example 2, the catalyst preparation is placed in an ice bath to reduce the reaction temperature and slow down the reaction rate, which causes the uniform growth of polyacrylamide on the surface of the alumina carrier, and does not form a steric hindrance effect, which does not leave space for the growth of active components and cocatalyst components as much as example 2, and the prepared catalyst synaptic structure may be lower, thereby causing the denitration and carbon monoxide removal activity to decrease.

Claims

1. A nanospherical low-temperature rare-earth-based de-NOx de-CO catalyst, characterized by: The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method.

2. A process for the preparation of the catalyst of claim 1, characterized in that: The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method. The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method. The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method. The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method. The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method. The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method. The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method.

3. The method of claim 2, wherein: The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method.

4. The method of claim 2, wherein: The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method.

5. The method of claim 2, wherein: The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method.

6. The method of claim 2, wherein: The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method.

7. The method of claim 2, wherein: The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method. The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method. The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method. The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method. The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method. The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method. The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method. The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method. The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method. The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium dioxide as an active component, iron oxide as a cocatalyst, ammonia water as a pH controller, p-hydroxybenzoic acid as a morphology controller, and polyacrylamide as a template agent, and by using a high-temperature hydrothermal-incomplete inverse emulsion polymerization-impregnation loading method. The catalyst is prepared by using alumina nanospheres as a carrier, a composite oxide of manganese dioxide and cerium 8. The method of claim 2, wherein: The drying temperature in step (3) is 80-100 DEG C, the drying time is 6-12h; the calcination temperature is 500-600 DEG C, and the calcination time is 3-6h.

9. The use of the catalyst of claim 1 in the denitration and decarbon monoxide of low-temperature flue gas in non-electricity industry.

10. Use according to claim 9, characterized in that, The non-electricity industry specifically refers to the steel sintering industry and the chemical industry.

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