Preparation method and application of nano-porous ceramic rare earth-based denitration and chlorobenzene removal catalyst

Abstract

The invention discloses a preparation method and application of a nano-porous ceramic rare earth-based denitration and dechlorobenzene catalyst. The catalyst takes a composite oxide of titanium dioxide and magnesium oxide as a carrier, takes a composite oxide of nickel oxide and cerium dioxide as an active component, takes bacillus subtilis as a structure-directing agent and takes magnesium powder as a combustion agent; according to the invention, sodium perchlorate is taken as an initiator, ammonium bicarbonate is taken as a pore-forming agent, and a biological template method, a freezing pore-forming method, a self-propagating high-temperature synthesis method and an impregnation loading method are combined for preparation. The catalyst synthesized by the invention has the advantages of large specific surface area, sufficient exposure of active sites and the like, and can realize simultaneous denitration and chlorobenzene removal of complex flue gas in the non-electric industry.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method and application of a nanoporous ceramic rare earth-based denitration and dechlorobenzene catalyst, and belongs to the field of industrial flue gas purification. BACKGROUND

[0002] Both the EU Industrial Emission Directive (IED) and the US Clean Air Act (CAA) have made clear requirements for the coordinated treatment of multiple pollutants. For example, the EU requires that the dioxin emissions of waste incineration plants be less than 0.1 ng TEQ / m 3 , and the coordinated emissions of NO x and VOCs need to be controlled. These policy pressures have driven the urgent need for integrated treatment technology for multiple pollutants in non-electricity industries.

[0003] The flue gas of non-electricity industries is complex and has the following significant characteristics: (1) low temperature and high humidity: the temperature of steel sintering flue gas is usually 80-180 DEG C, and the moisture content is 7-15%; the temperature of coke oven gas fluctuates greatly (100-400 DEG C), and the humidity is as high as 10-20%. The traditional selective catalytic reduction (SCR) catalyst is easy to be blocked and deactivated by ammonium bisulfate (ABS) under this condition; (2) multiple pollutants coexist: in addition to NO x , the flue gas often contains high concentrations of SO (3000-5000 mg / m 3 ), HCl (up to 500 mg / m 3 ), heavy metals (such as As and Hg) and VOCs such as chlorobenzene; the coupled competition adsorption and reaction paths of multiple components increase the treatment difficulty. However, the existing technologies (such as separate SCR denitration and activated carbon adsorption dechlorobenzene) are insufficient in efficiency, the activity of the SCR catalyst is low (NO x conversion rate < 50%) at low temperature, and the adsorption capacity of activated carbon for chlorobenzene is limited (< 200 mg / g); at the same time, the step-by-step treatment process is complex, and cross interference may occur between pollutants.

[0004] Therefore, the development of a low-temperature and high-efficiency multiple pollutant coordinated purification catalyst material has become a core issue for the green transformation of non-electricity industries. SUMMARY

[0005] The purpose of the present application is to solve the problems of the low-temperature catalytic activity of the existing non-electricity industry flue gas denitration and dechlorobenzene catalyst, and to propose a preparation method and application of a nanoporous ceramic rare earth-based denitration and dechlorobenzene catalyst.

[0006] The purpose of the present application can be achieved by the following technical solutions:

[0007] A nanoporous ceramic rare earth-based denitration and dechlorobenzene catalyst uses a composite oxide of titanium dioxide and magnesium oxide as a carrier, a composite oxide of nickel oxide and ceria as an active component, Bacillus subtilis as a structure-directing agent, magnesium powder as a combustion agent, sodium perchlorate as an initiator, and ammonium bicarbonate as a pore-forming agent. The catalyst is prepared by a combined bio-template method, a freezing pore-forming method, a self-propagating high-temperature synthesis method, and an impregnation loading method. The catalyst has a mass percentage of the active component of 5-20% based on the mass of the carrier, a mass ratio of nickel oxide to ceria in the active component of 1:(0.5-9), and a mass ratio of titanium dioxide to magnesium oxide in the carrier of 1:(0.5-2).

[0008] A method for preparing the above catalyst is as follows:

[0009] (1) Preparation of vector templates by biological template method

[0010] Bacillus subtilis (CGMCC 1.8801) was placed in a sterilized LB medium and cultured in a constant temperature shaker. After the culture was completed, the cells were collected by centrifugation. The cells were washed with phosphate buffer and then dried to obtain pure Bacillus subtilis for use.

[0011] (2) Preparation of carrier intermediates by cryopore formation

[0012] The titanium salt, ethanol, and polyvinyl pyrrolidone are uniformly mixed to prepare a precursor solution, and then the purified Bacillus subtilis prepared in step (1) is placed in the precursor solution, and the mixed solution is then placed in a vacuum drying oven for vacuum impregnation, and after impregnation, the mixed solution is placed in a constant temperature and humidity incubator for hydrolysis, and after the hydrolysis is completed, the mixed solution is frozen in liquid nitrogen, and after freezing, the mixed solution is placed in a vacuum freeze drying oven for drying to obtain a carrier intermediate;

[0013] (3) Preparation of carrier by self-propagating high temperature synthesis

[0014] Mixing magnesium powder, sodium perchlorate, ammonium bicarbonate, and the carrier intermediate obtained in step (2) uniformly and placing the mixture in a ceramic crucible, then heating the ceramic crucible, and washing the mixture with deionized water after spontaneous combustion ends and drying to obtain a composite carrier;

[0015] (4) Preparation of catalyst by impregnation loading

[0016] Nickel salt, cerium salt and deionized water are mixed evenly to obtain an active component precursor solution, and the composite carrier obtained in step (3) is placed in the active component precursor solution, impregnated, dried and then placed in a muffle furnace for calcination to obtain a catalyst.

[0017] In the above preparation method: the drying temperature in step (1) is 20-30° C., the drying time is 24-48 hours, and the pH value of the phosphate buffer is 7.2-7.4.

[0018] In the above preparation method: the titanium salt described in step (2) is tetrabutyl titanate or tetraethyl titanate, and the mass ratio of titanium salt, ethanol, polyvinyl pyrrolidone, and pure Bacillus subtilis is 5-20:90-160:0.5-1.5:5-20.

[0019] In the above preparation method: the temperature of the vacuum impregnation described in step (2) is 25-35°C, the vacuum degree of the vacuum impregnation is 0.05-0.1 MPa, and the maintenance time of the vacuum impregnation is 6-12 hours; the temperature of the hydrolysis is 25-35°C, the humidity of the hydrolysis is 60-80%, and the hydrolysis time is 24-48 hours; the freezing time in liquid nitrogen is 5-10 minutes, the drying temperature is -40--50°C, and the drying time is 24-48 hours.

[0020] In the above preparation method, the mass ratio of the magnesium powder, sodium perchlorate, and ammonium bicarbonate described in step (3) is 1:(1-2):(0.2-0.4); the heating temperature is 500-600° C., and the heating time is 5-10 minutes; the drying temperature is 40-60° C., and the drying time is 12-24 hours.

[0021] In the above preparation method: the nickel salt described in step (4) is nickel nitrate hexahydrate or nickel chloride hexahydrate, and the cerium salt is cerium nitrate hexahydrate or cerium chloride; the impregnation time is 30 to 60 minutes; the drying temperature is 80 to 100° C., and the drying time is 4 to 8 hours; the roasting temperature is 500 to 700° C., and the roasting time is 4 to 8 hours.

[0022] In the technical solution of the present invention, the catalyst is used in the treatment of complex flue gas in non-electricity industries.

[0023] Furthermore, the flue gas treatment specifically refers to the simultaneous catalytic reduction of nitrogen oxides and the catalytic oxidation of chlorobenzene.

[0024] The catalyst activity evaluation experimental conditions of the present invention are as follows: 1 mL of a 20-40 mesh catalyst is poured into a quartz tube with an internal diameter of 8 mm, fixed with quartz wool and wire mesh, and placed in a tube furnace. The actual temperature of the catalytic reaction is adjusted by controlling the heating temperature of the tube furnace. The intake gas components are NO (500 ppm), NH3 (500 ppm), O2 (10 vol.%), chlorobenzene (200 ppm), and the rest is N2. The total gas flow rate is 500 mL / min. The temperature is controlled at 120-300°C, and the temperature is stabilized at 30°C for 30 minutes. The NO concentration is measured by a flue gas analyzer, and the chlorobenzene concentration is measured by gas chromatography. Within the temperature range of 180-300°C, the catalyst denitration efficiency is higher than 90%, and the chlorobenzene oxidation efficiency is higher than 90%.

[0025] Beneficial effects:

[0026] (1) The present invention cultivates Bacillus subtilis as a biological template and structure-directing agent, which can not only make titanium salt adsorbed on the outer surface of bacteria under vacuum impregnation conditions, but also allow titanium salt hydrolyzate to enter the interior of the cell during the destruction of the Bacillus subtilis cell wall during freeze pore formation, thereby accurately replicating the morphology of Bacillus subtilis and forming a nanopore structure. At the same time, because no chemical template is required and the cost of bacterial cultivation is low, the process sustainability is improved; in addition, during the titanium salt impregnation and hydrolysis process, the present invention uses liquid nitrogen freezing method to utilize ice crystal growth to exclude titanium salt intermediates to form layered channels, and obtains more microscopic channels as the ice crystals sublimate; by combining the biological template method of Bacillus subtilis and the freeze pore formation method, the carrier intermediate can form hierarchical micro-nanopores, thereby promoting the improvement of catalytic activity;

[0027] (2) The present invention utilizes magnesium powder and sodium perchlorate to generate an exothermic reaction under heating conditions to form self-propagating combustion, which not only can form ceramic carrier particles in a very short time, but also the thermal decomposition of ammonium bicarbonate can release gas, further forming a pore structure, ensuring the formation of a hierarchical micro-nano pore structure of the carrier. In addition, the self-propagating high-temperature synthesis method not only has extremely low energy consumption, but also the porosity of the ceramic carrier particles can be independently controlled by the pore-forming agent ammonium bicarbonate;

[0028] (3) The present invention combines the bio-template method, the freezing pore formation method and the self-propagating high-temperature synthesis method to make titanium dioxide and magnesium oxide into hierarchical porous ceramic carriers, wherein the macropores can serve as fast channels for the reaction molecules to reduce the diffusion resistance, the mesopores can serve as reaction channels, provide sufficient specific surface area and diffusion paths to promote the contact between the reaction molecules and the active sites, and the micropores serve as active site warehouses to anchor Ce 4+ 、Ni 2+ High density of catalytic active sites enhances local reaction dynamics; at the same time, hierarchical channels can prolong the residence time of reacting molecules and form abundant defect sites, thereby enhancing the adsorption and activation ability of reacting molecules;

[0029] (4) The present invention utilizes a composite oxide of titanium dioxide and magnesium oxide as a carrier, and a composite oxide of nickel oxide and cerium oxide as an active component, wherein titanium dioxide has a high specific surface area and surface acidity. Although the composite of magnesium oxide and titanium dioxide partially reduces the surface acidity of the carrier, it can adsorb acidic gases such as SO2 in the flue gas during the actual gas reaction process, thereby preventing the active sites from reacting with acidic gases such as SO2. Moreover, magnesium oxide can promote titanium dioxide to form a ceramic carrier, further improving the mechanical strength of the carrier. Both nickel oxide and cerium oxide have excellent redox properties, and can form a solid solution to enhance the number and strength of acidic sites on the catalyst surface, thereby ensuring the low-temperature performance of the catalyst.

[0030] Therefore, the catalyst synthesized in the present invention has the advantages of large specific surface area and fully exposed active sites, and can achieve simultaneous denitrification and dechlorobenzene removal of complex flue gases in non-power industries. Moreover, the catalyst component is environmentally friendly, cost-effective, and has strong application and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a scanning electron microscope image of the catalyst prepared in Example 1;

[0032] Figure 2 This is a scanning electron microscope image of the catalyst prepared in Example 1;

[0033] Figure 3 This is the pore size distribution diagram of the catalyst prepared in Example 1;

[0034] Figure 4 This is the pore size distribution diagram of the catalyst prepared in Comparative Example 1;

[0035] Figure 5 The NO removal performance diagram of the catalysts prepared in Examples 1-3 and Comparative Example 1;

[0036] Figure 6 This is a performance diagram of chlorobenzene oxidation of the catalysts prepared in Examples 1-3 and Comparative Example 1. DETAILED DESCRIPTION

[0037] The present invention will be further described below with reference to the following examples. The examples are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operating processes. However, the protection scope of the present invention is not limited to the following examples.

[0038] The Bacillus subtilis (CGMCC 1.8801) used in the examples was purchased from the China General Microbiological Culture Collection Center.

[0039] Example 1

[0040] (1) Preparation of vector templates by biological template method

[0041] Weigh 10 g of Bacillus subtilis and place it in a sterilized LB culture medium. Culture it in a 36°C constant temperature shaker at 100 rpm for 3 days. After the culture is complete, centrifuge it at 6000 rpm for 10 minutes to collect the cells.

[0042] The cells were washed three times with a phosphate buffer solution having a pH value of 7.2 and dried at 20°C for 24 hours to obtain pure Bacillus subtilis for later use;

[0043] (2) Preparation of carrier intermediates by cryopore formation

[0044] 16 g of tetrabutyl titanate, 96 g of ethanol, and 0.8 g of polyvinyl pyrrolidone were weighed and mixed uniformly to prepare a precursor solution, and then 8 g of the purified Bacillus subtilis prepared in step (1) was placed in the precursor solution, and then the mixed solution was placed in a vacuum drying oven at 25°C and vacuum-impregnated at a vacuum degree of 0.05 MPa for 6 h. After impregnation, the mixed solution was placed in a constant temperature and humidity incubator at 25°C and hydrolyzed at 60% humidity for 24 h. After the hydrolysis was completed, it was placed in 604 g of liquid nitrogen and frozen for 5 min. Finally, it was placed in a vacuum freeze drying oven at -40°C and dried for 12 h to obtain a carrier intermediate for use;

[0045] (3) Preparation of carrier by self-propagating high temperature synthesis

[0046] Weigh 0.57 g of magnesium powder, 0.57 g of sodium perchlorate, 0.12 g of ammonium bicarbonate, and 12.4 g of the carrier intermediate prepared in step (2), mix them evenly, and place them in a ceramic crucible. Then, heat the ceramic crucible at 500° C. for 5 min. After the mixture spontaneously burns, wash it with deionized water and dry it at 40° C. for 24 h to obtain a composite carrier.

[0047] (4) Preparation of catalyst by impregnation loading

[0048] Weigh 0.33g of nickel nitrate hexahydrate, 0.11g of cerium nitrate hexahydrate, and 25.6g of deionized water and mix them evenly to prepare an active component precursor solution. Then, 2.5g of the composite support prepared in step (3) is placed in the active component precursor solution and immersed for 30min. After impregnation, it is dried at 80°C for 4h and then placed in a muffle furnace and calcined at 500°C for 4h to obtain a catalyst (based on the mass of the support, the mass percentage of the active component - is 5%, the mass ratio of nickel oxide and cerium dioxide in the active component is 1:0.5, and the mass ratio of titanium dioxide and magnesium oxide in the support is 1:0.5. The scanning electron microscope image of the catalyst is as follows Figure 1 and Figure 2 As shown, the pore size distribution diagram measured by mercury intrusion method is shown in Figure 3);

[0049] (5) Catalytic activity test

[0050] Take 1mL of 20-40 mesh catalyst, pour it into a quartz tube with an inner diameter of 6mm, fix it with quartz wool and wire mesh, 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. Intake components: NO (500ppm), NH3 (500ppm), O2 (11vol.%), chlorobenzene (400ppm), and the rest are N2. The total gas flow rate is 500mL / min, and the temperature is controlled at 120-240℃. Stay stable for 30min every 30℃. Use gas chromatography to measure the chlorobenzene concentration, and flue gas analyzer to measure the NO concentration. In the temperature range of 150-240℃, the catalyst dechlorobenzene efficiency and denitrification efficiency are both higher than 90%. Figures 5-6 .

[0051] Example 2

[0052] (1) Preparation of vector templates by biological template method

[0053] 14 g of Bacillus subtilis was placed in a sterilized LB culture medium and cultured in a 37°C constant temperature shaker at 150 rpm for 5 days. After the culture, the cells were collected by centrifugation at 8000 rpm for 20 minutes. The cells were washed three times with phosphate buffer and dried at 25°C for 48 hours to obtain pure Bacillus subtilis for use.

[0054] (2) Preparation of carrier intermediates by cryopore formation

[0055] Weigh 15 g of tetraethyl titanate, 150 g of ethanol, and 1.2 g of polyvinyl pyrrolidone and mix them evenly to prepare a precursor solution. Then, place 15 g of the purified Bacillus subtilis prepared in step (1) in the precursor solution. Then, place the mixed solution in a vacuum drying oven at 30° C. and evacuate at a vacuum degree of 0.1 MPa for 9 h. After immersion, place the mixed solution in a constant temperature and humidity incubator at 30° C. and hydrolyze at 70% humidity for 36 h. After the hydrolysis is completed, place the mixed solution in 1812.0 g of liquid nitrogen and freeze it for 10 min. Finally, place the mixed solution in a vacuum freeze drying oven and dry it at -50° C. for 16 h to obtain a carrier intermediate for use.

[0056] (3) Preparation of carrier by self-propagating high temperature synthesis

[0057] Weigh 2.11 g of magnesium powder, 3.2 g of sodium perchlorate, 0.63 g of ammonium bicarbonate, and 20.8 g of the carrier intermediate prepared in step (2), mix them evenly, and place them in a ceramic crucible. Then, heat the ceramic crucible at 500° C. for 10 min. After the mixture spontaneously burns, wash it with deionized water and dry it at 60° C. for 24 h to obtain a composite carrier.

[0058] (4) Preparation of catalyst by impregnation loading

[0059] Weigh 0.3 g of nickel chloride hexahydrate, 0.67 g of cerium chloride, and 36 g of deionized water and mix them evenly to prepare an active component precursor solution. Then, 5.6 g of the composite support prepared in step (3) is placed in the active component precursor solution and immersed for 50 min. After impregnation, it is dried at 90° C. for 8 h and then placed in a muffle furnace and calcined at 600° C. for 8 h to obtain a catalyst (based on the mass of the support, the mass percentage of the active component is 8%, the mass ratio of nickel oxide to cerium dioxide in the active component is 1:5, and the mass ratio of titanium dioxide to magnesium oxide in the support is 1:1);

[0060] (5) Catalytic activity test

[0061] Take 1mL of 20-40 mesh catalyst, pour it into a quartz tube with an inner diameter of 6mm, fix it with quartz wool and wire mesh, 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. Intake components: NO (500ppm), NH3 (500ppm), O2 (11vol.%), chlorobenzene (400ppm), and the rest are N2. The total gas flow rate is 500mL / min, and the temperature is controlled at 120-240℃. Stay stable for 30min every 30℃. Use gas chromatography to measure the chlorobenzene concentration, and flue gas analyzer to measure the NO concentration. In the temperature range of 150-240℃, the catalyst dechlorobenzene efficiency and denitrification efficiency are both higher than 90%. Figures 5-6 .

[0062] Example 3

[0063] (1) Preparation of vector templates by biological template method

[0064] 20 g of Bacillus subtilis was placed in a sterilized culture medium and cultured at 38°C in a constant temperature shaker at 200 rpm for 7 days. After the culture was completed, the cells were collected by centrifugation at 9000 rpm for 20 minutes. The cells were washed three times with phosphate buffer and dried at 30°C for 48 hours to obtain pure Bacillus subtilis for use.

[0065] (2) Preparation of carrier intermediates by cryopore formation

[0066] 8 g of tetrabutyl titanate, 96 g of ethanol, and 0.8 g of polyvinyl pyrrolidone were weighed and mixed uniformly to prepare a precursor solution, and then 16 g of the purified Bacillus subtilis prepared in step (1) was placed in the precursor solution, and the mixed solution was placed in a vacuum drying oven at 25° C. and vacuum-impregnated at a vacuum degree of 0.05 MPa for 12 h. After impregnation, the mixed solution was placed in a constant temperature and humidity incubator at 35° C. and hydrolyzed at 80% humidity for 48 h. After the hydrolysis was completed, it was placed in 724.8 g of liquid nitrogen and frozen for 8 min. Finally, it was placed in a vacuum freeze drying oven at -40° C. and dried for 16 h to obtain a carrier intermediate for use;

[0067] (3) Preparation of carrier by self-propagating high temperature synthesis

[0068] Weigh 2.23 g of magnesium powder, 4.26 g of sodium perchlorate, 0.8 g of ammonium bicarbonate, and 19.8 g of the carrier intermediate prepared in step (2), mix them evenly, and place them in a ceramic crucible. Then, heat the ceramic crucible at 600° C. for 10 min. After the mixture spontaneously burns, wash it with deionized water and dry it (at 40° C. for 15 h) to obtain a composite carrier.

[0069] (4) Preparation of catalyst by impregnation loading

[0070] Weigh 0.33 g of nickel nitrate hexahydrate, 1.91 g of cerium nitrate hexahydrate, and 41 g of deionized water and mix them evenly to prepare an active component precursor solution. Then, 4.2 g of the composite support prepared in step (3) is placed in the active component precursor solution and immersed for 30 min. After impregnation, it is dried at 100° C. for 8 h and then placed in a muffle furnace and calcined at 700° C. for 8 h to obtain a catalyst (based on the mass of the support, the mass percentage of the active component is 20%, the mass ratio of nickel oxide to cerium dioxide in the active component is 1:9, and the mass ratio of titanium dioxide to magnesium oxide in the support is 1:2);

[0071] (5) Catalytic activity test

[0072] Take 1mL of 20-40 mesh catalyst, pour it into a quartz tube with an inner diameter of 6mm, fix it with quartz wool and wire mesh, 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. Intake components: NO (500ppm), NH3 (500ppm), O2 (11vol.%), chlorobenzene (400ppm), and the rest are N2. The total gas flow rate is 500mL / min, and the temperature is controlled at 120-240℃. Stay stable for 30min every 30℃. Use gas chromatography to measure the chlorobenzene concentration, and flue gas analyzer to measure the NO concentration. In the temperature range of 150-240℃, the catalyst dechlorobenzene efficiency and denitrification efficiency are both higher than 90%. Figures 5-6 .

[0073] Comparative Example 1

[0074] (1) Preparation of carrier

[0075] Except that Bacillus subtilis was not used in the preparation of the catalyst, other conditions were the same as those in Example 1;

[0076] (2) Catalytic activity test

[0077] 1 mL of a 20-40 mesh catalyst was poured into a 6 mm inner diameter quartz tube, secured with quartz wool and wire mesh. The tube was then placed in a tubular furnace, and the actual temperature of the catalytic reaction was adjusted by controlling the heating temperature of the tubular furnace. The inlet gas components included NO (500 ppm), NH3 (500 ppm), O2 (11 vol.%), chlorobenzene (400 ppm), and the remainder was N2. The total gas flow rate was 500 mL / min, and the temperature was controlled at 120-240°C, with 30-minute dwell times at 30°C intervals. The chlorobenzene concentration was measured by gas chromatography, and the NO concentration was measured by a flue gas analyzer. At 180°C, the catalyst achieved a 45.6% dechlorobenzene efficiency and a 56.3% denitrification efficiency.

[0078] (3) Contrast effect

[0079] Compared with Example 1, Bacillus subtilis is not used in the catalyst preparation step (1), and the micropores of the catalyst disappear ( Figure 4 ), the exposure ratio of active sites decreases, resulting in a significant decrease in catalytic activity, such as Figures 5-6 .

Claims

1. A nanoporous ceramic rare earth-based denitrification and dechlorobenzene catalyst, characterized by: The composite oxide of titanium dioxide and magnesium oxide is used as a carrier, the composite oxide of nickel oxide and cerium dioxide is used as an active component, Bacillus subtilis is used as a structure-directing agent, magnesium powder is used as a combustion agent, sodium perchlorate is used as an initiator, and ammonium bicarbonate is used as a pore-forming agent. The composite oxide is prepared by a bio-template method-freeze pore-forming method-self-propagating high-temperature synthesis method-impregnation loading method. Based on the mass of the carrier, the mass percentage of the active component is 5~20%, the mass ratio of nickel oxide to cerium dioxide in the active component is 1:(0.5~9), and the mass ratio of titanium dioxide to magnesium oxide in the carrier is 1:(0.5~2).

2. A method for preparing the catalyst according to claim 1, characterized in that: The preparation method of the catalyst is as follows: (1) Preparation of vector templates using the biological template method Bacillus subtilis (CGMCC 1.8801) was placed in a sterilized LB medium and cultured in a constant temperature shaker. After the culture was completed, the cells were collected by centrifugation. The cells were washed with phosphate buffer and then dried to obtain pure Bacillus subtilis for use. (2) Preparation of carrier intermediates by cryopore formation The titanium salt, ethanol and polyvinyl pyrrolidone are uniformly mixed to prepare a precursor solution, and then the purified Bacillus subtilis prepared in step (1) is placed in the precursor solution, and then the mixed solution is placed in a vacuum drying oven for vacuum impregnation, and after impregnation, the mixed solution is placed in a constant temperature and humidity incubator for hydrolysis, and after the hydrolysis is completed, it is frozen in liquid nitrogen, and after freezing, it is placed in a vacuum freeze drying oven for drying to obtain a carrier intermediate; (3) Preparation of carrier by self-propagating high-temperature synthesis Mixing magnesium powder, sodium perchlorate, ammonium bicarbonate, and the carrier intermediate obtained in step (2) uniformly and placing the mixture in a ceramic crucible, then heating the ceramic crucible, and washing the mixture with deionized water and drying the mixture after spontaneous combustion is complete to obtain a composite carrier; (4) Preparation of catalyst by impregnation loading Nickel salt, cerium salt and deionized water are mixed evenly to obtain an active component precursor solution, and the composite carrier obtained in step (3) is placed in the active component precursor solution, impregnated, dried and then placed in a muffle furnace for calcination to obtain a catalyst.

3. The preparation method according to claim 2, wherein: The drying temperature in step (1) is 20-30° C., the drying time is 24-48 h, and the pH value of the phosphate buffer is 7.2-7.

4.

4. The preparation method according to claim 2, wherein: The titanium salt described in step (2) is tetrabutyl titanate or tetraethyl titanate, and the mass ratio of the titanium salt, ethanol, polyvinyl pyrrolidone, and purified Bacillus subtilis is 5-20:90-160:0.5-1.5:5-20.

5. The preparation method according to claim 2, wherein: The temperature of the vacuum impregnation described in step (2) is 25~35°C, the vacuum degree of the vacuum impregnation is 0.05~0.1MPa, and the maintenance time of the vacuum impregnation is 6~12h; the temperature of the hydrolysis is 25~35°C, the humidity of the hydrolysis is 60~80%, and the hydrolysis time is 24~48h; the freezing time in liquid nitrogen is 5~10min, the drying temperature is -40~-50°C, and the drying time is 24~48h.

6. The preparation method according to claim 2, wherein: The mass ratio of magnesium powder, sodium perchlorate and ammonium bicarbonate described in step (3) is 1: (1-2): (0.2-0.4); the heating temperature is 500-600°C, and the heating time is 5-10 minutes; the drying temperature is 40-60°C, and the drying time is 12-24 hours.

7. The preparation method according to claim 2, characterized in that: The nickel salt described in step (4) is nickel nitrate hexahydrate or nickel chloride hexahydrate, and the cerium salt is cerium nitrate hexahydrate or cerium chloride; the impregnation time is 30-60 minutes; the drying temperature is 80-100°C, and the drying time is 4-8 hours; the roasting temperature is 500-700°C, and the roasting time is 4-8 hours.

8. Use of the catalyst according to claim 1 in the treatment of complex flue gas in non-electricity industries.

9. The flue gas treatment according to claim 8 specifically refers to the simultaneous catalytic reduction of nitrogen oxides and catalytic oxidation of chlorobenzene.

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