Low-temperature rare-earth-based denitration and chlorobenzene removal catalyst as well as preparation method and application thereof

Abstract

The invention discloses a low-temperature rare-earth-based denitration and chlorobenzene removal catalyst as well as a preparation method and application thereof. The catalyst takes microrod titanium dioxide as a carrier and takes a cerium oxide and ferroferric oxide nanoneedle composite oxide as an active component; by taking the mass of the carrier as a reference, the mass percentage of the active component is 5-10%. The catalyst synthesized by the method has the advantages of high low-temperature activity, strong sulfur poisoning resistance and the like, and can realize the goal of denitration and chlorobenzene removal of complex flue gas in non-electric industries.

Description

Technical Field

[0001] The invention relates to a low-temperature rare earth-based denitration and dechlorobenzene catalyst, a preparation method and application thereof, and belongs to the field of air pollution control. Background Art

[0002] The non-electric industry needs to conduct research and development in the field of air pollution control in two directions: (1) High-efficiency low-temperature catalysts. The flue gas temperature in the non-electric industry is generally low. If medium- and high-temperature denitrification catalysts are used, the company needs to heat the flue gas, which increases additional costs. At low temperatures, the catalysts are easily poisoned and inactivated due to the complex flue gas composition of the non-electric industry. (2) Coordinated control of multiple pollutants. Single control of different components in the flue gas will increase the company's control costs. Coordinated control of multiple pollutants can not only integrate the control processes of multiple pollutants into the same equipment or system, reducing the purchase, installation and maintenance costs of multiple equipment, but also reduce the generation of secondary pollutants, ensuring that the treatment process is more environmentally friendly.

[0003] At present, researchers have developed a series of simultaneous denitrification and dechlorobenzene technologies: (1) SCR and dechlorobenzene technology are combined to develop a new type of bifunctional catalyst that can simultaneously catalyze NO x For example, some metal oxides or noble metal catalysts react with NO under certain conditions. x It has good catalytic activity with chlorobenzene and can treat two pollutants simultaneously in the same reactor; (2) Activated carbon adsorption is combined with SCR. Activated carbon can adsorb chlorobenzene substances, while SCR technology can effectively remove NO x By combining these two technologies, multiple pollutants can be treated simultaneously in one system, especially when treating industrial emissions with high temperature and high concentration of gases. (3) Photocatalytic technology, by using ultraviolet light to irradiate the catalyst, can simultaneously activate NO x and chlorobenzene degradation reactions. Studies have shown that certain photocatalysts (such as TiO 2 ) can effectively decompose NO under ultraviolet light x and chlorobenzene, achieving a synergistic removal effect. The advantages of photocatalytic technology are that it is simple to operate, environmentally friendly, and can be carried out at room temperature and pressure, but the challenges it faces are the stability and cost of the catalyst; (4) Wet scrubbing and adsorption combined technology, the combination of wet scrubbing and adsorption is also an effective synergistic treatment method. Wet scrubbing can effectively remove NO in the gas. x , and the adsorption method can be used to treat chlorobenzene substances. By adjusting the pH value of the washing liquid, the selection of the adsorbent and the conditions of use, NO x and chlorobenzene.

[0004] Among the above-mentioned technologies, the development of new bifunctional catalysts is the technology with the most cost and technical advantages, mainly because the non-electric industry currently generally uses SCR technology for denitrification. Therefore, the development and application of bifunctional catalysts do not require companies to modify related equipment, but only need to replace related catalysts. Therefore, the development of low-cost, non-toxic and efficient new denitrification and dechlorobenzene catalysts is of great significance, especially when dealing with complex flue gas conditions in the non-electric industry. Summary of the invention

[0005] The purpose of the present invention is to propose a low-temperature rare earth-based denitration and dechlorobenzene catalyst and its preparation method and application in view of the current status and existing problems of simultaneous denitration and dechlorobenzene in the existing non-electricity industry.

[0006] A low-temperature rare earth-based denitration and dechlorobenzene catalyst, characterized in that: the catalyst uses micron-rod titanium dioxide as a carrier, and nano-needle composite oxides of cerium oxide and ferroferric oxide as active components, and is prepared by an electrochemical deposition-magnetic field induced solvent thermal combined method; wherein, based on the mass of the carrier, the mass percentage of the active component is 5-10%, and the mass ratio of cerium oxide to ferroferric oxide in the active component is 1:(0.5-1).

[0007] The preparation method of the catalyst is as follows:

[0008] (1) Preparation of microrod titanium dioxide by electrochemical deposition

[0009] Weigh potassium fluoride, ethanol, and deionized water and mix them evenly to prepare an electrolyte, then drop nitric acid into the electrolyte to adjust the pH, use a titanium wire as a working electrode, a platinum electrode as a counter electrode, and a saturated calomel electrode as a reference electrode, then add the electrolyte into a glass electrolytic cell and fix the three electrodes in the electrolytic cell, place the electrolytic cell in a water bath, pass current during the water bath to perform electrolytic deposition, scrape off the titanium dioxide on the surface of the titanium electrode after the deposition is completed, dry it, and then place it in a muffle furnace for high-temperature roasting to obtain micro-rod titanium dioxide;

[0010] (2) Preparation of nanoneedle active components by magnetic field-induced solvothermal method

[0011] A cerium source, an iron source, a reducing agent, and deionized water are weighed and mixed evenly to prepare a precursor solution, and then a sodium hydroxide solution is added dropwise to the precursor solution to adjust the pH value, and then the precursor solution is poured into a hydrothermal reactor, and then a copper wire is wound around the outside of the hydrothermal reactor, and then the hydrothermal reactor with the copper wire wound is placed in an oil bath pot, and the oil bath is heated to perform a solvent thermal reaction, and at the same time of the solvent thermal reaction, both ends of the copper wire are connected to a DC power supply, and a voltage is applied to form an external magnetic field, and after the reaction is completed, the solution is filtered and dried, and then placed in a muffle furnace for calcination to obtain a nano-needle composite oxide of cerium oxide and ferroferric oxide;

[0012] (3) Microwave-assisted preparation of catalysts

[0013] The micron-rod titanium dioxide obtained in step (1), the nano-needle composite oxide obtained in step (2) and deionized water are uniformly mixed, placed in a microwave sintering furnace after ultrasonic oscillation, and sintered by microwave heating to obtain a catalyst.

[0014] In the technical solution of the present invention: the mass ratio of potassium fluoride, ethanol and deionized water described in step (1) is 1: (20-40): (60-80), the nitric acid is a dilute nitric acid solution with a mass fraction of 5% to 10%, and the pH value is adjusted to 3-6.

[0015] In the technical solution of the present invention: the titanium wire described in step (1) is a titanium metal wire with a length of 50 to 100 mm and a diameter of 3 to 5 mm, the counter electrode is a platinum electrode, model 213 / 213-01, a diameter of 12 mm, and a length of 120 mm, and the reference electrode is a saturated calomel electrode, model 232 / 232-01, a diameter of 5 mm, and a length of 50 mm.

[0016] In the technical scheme of the present invention: the temperature of the water bath described in step (1) is 25-40°C, the current passed is 5-10 mA, the time of electrolytic deposition is 4-8 hours, the temperature of drying is 80-100°C, the time of drying is 4-8 hours, the temperature of high-temperature calcination is 400-600°C, and the time of high-temperature calcination is 2-4 hours.

[0017] In the technical scheme of the present invention: the cerium source described in step (2) is cerium chloride or cerium nitrate hexahydrate, the iron source is ferric chloride hexahydrate or ferric nitrate nonahydrate, the reducing agent is citric acid monohydrate or ethylene glycol, the mass ratio of the cerium source, the reducing agent and deionized water is 1: (1-3): (60-100), the mass fraction of the sodium hydroxide solution is 10%-20%, and the adjusted pH is 8-9.

[0018] In the technical scheme of the present invention: the diameter of the copper wire described in step (2) is 2-3 mm, the number of turns of winding is 100-200 turns, the solvent in the oil bath pot is dimethyl sulfoxide, the temperature of the oil bath heating is 140-160° C., the time of the oil bath heating is 6-12 h, the applied voltage is 10-30 V, the drying temperature is 80-100° C., the drying time is 4-8 h, the roasting temperature is 500-600° C., and the roasting time is 2-4 h.

[0019] In the technical solution of the present invention: the mass ratio of the microrod titanium dioxide and deionized water in step (3) is 1: (40-80), the power of ultrasonic oscillation is 150-300W, the time of ultrasonic oscillation is 1-2h, the power of microwave heating sintering is 1.0-1.5kW, and the time of microwave heating sintering is 0.5-1h.

[0020] In the technical solution of the present invention: the above catalyst is used in the denitration and dechlorobenzene removal of complex flue gas in non-electricity industries.

[0021] In the technical solution of the present invention: the above-mentioned non-electricity industry specifically refers to steel sintering, dry cement and chemical industries.

[0022] The experimental conditions for evaluating the activity of the catalyst of the present invention are as follows: 1 mL of a 20-40 mesh catalyst is poured into a quartz tube with an inner diameter of 6 mm, fixed with quartz wool and wire mesh, and the quartz tube is placed in a tube furnace. The actual temperature of the catalytic reaction is adjusted by controlling the heating temperature of the tube furnace. Intake gas components: NO (500 ppm), NH 3 (500ppm), O 2 (11 vol.%), chlorobenzene (400 ppm), SO 2 (200ppm), the rest are N 2 The total gas flow rate was 500 mL / min, the temperature was controlled at 120-240°C, and it stayed stable for 30 min every 30°C. The chlorobenzene concentration was determined by gas chromatography, and the NO concentration was determined by flue gas analyzer. In the temperature range of 180-240°C, the catalyst dechlorobenzene efficiency and denitrification efficiency were both higher than 90%.

[0023] Beneficial effects:

[0024] (1) In the present invention, the micro-rod titanium dioxide is prepared by electrochemical deposition, wherein the fluorine ions in potassium fluoride can also interact with titanium ions to promote the vertical growth of the titanium dioxide micro-rods, so that the prepared titanium dioxide presents a micro-rod structure, and can promote the exposure of the high-energy crystal plane (001), improve the interaction between the carrier and the reaction molecules, and as an important component of the electrolyte, can also effectively reduce the resistance of the electrolyte, accelerate the deposition process and improve the crystallization quality of titanium dioxide;

[0025] (2) In the present invention, an iron source and a reducing agent are used to generate ferroferric oxide in a solvothermal reaction, and an external magnetic field can induce and control the long-axis growth direction of ferroferric oxide, so that it forms a nano-needle morphology in the solvothermal method, thereby realizing that the composite oxide of cerium oxide and ferroferric oxide is used as an active component to form a nano-needle structure, ultimately reducing the reaction energy barrier and promoting the improvement of low-temperature catalytic activity;

[0026] (3) In the present invention, micro-rod titanium dioxide is used as a carrier, and nano-needle-shaped composite oxides of cerium oxide and ferroferric oxide are used as active components. The catalyst surface is smooth and the high-energy crystal surface exposure ratio is higher, which can not only improve the contact and activation of the reaction molecules with the catalyst surface, but also simultaneously reduce the deposition of the reaction intermediate or poisoning substance ammonium bisulfate on the catalyst surface, so that the catalyst has both excellent low-temperature catalytic activity and anti-poisoning performance;

[0027] Therefore, the catalyst prepared by the present invention not only has excellent low-temperature denitration and dechlorobenzene performance, but also the catalyst component is environmentally friendly, has a simple preparation process, low cost, high cost performance, and has strong application and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the SEM image of the catalyst prepared in Example 1;

[0029] Figure 2 This is the SEM image of the catalyst prepared in Comparative Example 1;

[0030] Figure 3 The denitration efficiency diagram of the catalyst prepared in Examples 1-3 and Comparative Example 1;

[0031] Figure 4 This is a graph showing the dechlorobenzene efficiency of the catalysts prepared in Examples 1-3 and Comparative Example 1. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with examples. The examples are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating processes are given, but the protection scope of the present invention is not limited to the following examples.

[0033] Example 1

[0034] (1) Preparation of microrod titanium dioxide by electrochemical deposition

[0035] Weigh 1g potassium fluoride, 30g ethanol, and 70g deionized water and mix them evenly to prepare an electrolyte, then drop 7% nitric acid into the electrolyte to adjust the pH to 3, use a titanium wire with a length of 50mm and a diameter of 5mm as a working electrode, a platinum electrode with a diameter of 12mm and a length of 120mm (model 213 / 213-01) as a counter electrode, and a saturated calomel electrode with a diameter of 5mm and a length of 50mm (model 232 / 232-01) as a reference electrode, then add the electrolyte to a glass electrolytic cell and fix the three electrodes in the electrolytic cell, place the electrolytic cell in a water bath at 25°C, electrolytically deposit at a current of 5mA for 4h during the water bath, scrape off the titanium dioxide on the surface of the titanium electrode after the deposition is completed, dry it at 80°C for 4h, and then place it in a muffle furnace and calcine it at a high temperature of 400°C for 2h to obtain micro-rod titanium dioxide;

[0036] (2) Preparation of nanoneedle active components by magnetic field-induced solvothermal method

[0037] Weigh 2g of cerium chloride, 2.44g of ferric chloride hexahydrate, 2g of citric acid monohydrate, and 120g of deionized water and mix them evenly to prepare a precursor solution, then drip a 10% sodium hydroxide solution into the precursor solution to adjust the pH to 8, then pour it into a hydrothermal reactor, then wrap 100 turns of 2mm copper wire around the outside of the hydrothermal reactor, and then place the hydrothermal reactor wrapped with copper wire in an oil bath pot added with dimethyl sulfoxide, and heat it in an oil bath at 140°C for a solvothermal reaction for 6h. During the solvothermal reaction, connect both ends of the copper wire to a 10V DC power supply, apply voltage to form an external magnetic field, filter after the reaction, dry at 80°C for 4h, and place it in a muffle furnace at 500°C for 2h to obtain a nanoneedle composite oxide of cerium oxide and ferrosoferric oxide;

[0038] (3) Microwave-assisted preparation of catalysts

[0039] 20 g of the microrod titanium dioxide obtained in step (1), 1 g of the nanoneedle composite oxide obtained in step (2), and 40 g of deionized water were mixed evenly, subjected to 150 W ultrasonic oscillation for 1 h, placed in a microwave sintering furnace, and sintered for 0.5 h with 1 kW microwave heating to obtain a catalyst (based on the mass of the carrier, the mass percentage of the active component was 5%, and the mass ratio of cerium oxide to ferrosoferric oxide in the active component was 1:0.5);

[0040] (4) Catalytic activity test

[0041] The experimental conditions for evaluating the activity of the catalyst of the present invention are as follows: 1 mL of a 20-40 mesh catalyst is poured into a quartz tube with an inner diameter of 6 mm, fixed with quartz wool and wire mesh, and the quartz tube is placed in a tube furnace. The actual temperature of the catalytic reaction is adjusted by controlling the heating temperature of the tube furnace. Intake gas components: NO (500 ppm), NH 3 (500ppm), O 2 (11 vol.%), chlorobenzene (400 ppm), SO 2 (200ppm), the rest are N 2 The total gas flow rate was 500 mL / min, the temperature was controlled at 120-240°C, and it stayed stable for 30 min every 30°C. The chlorobenzene concentration was determined by gas chromatography, and the NO concentration was determined by flue gas analyzer. In the temperature range of 180-240°C, the catalyst dechlorobenzene efficiency and denitrification efficiency were both higher than 90%.

[0042] Example 2

[0043] (1) Preparation of microrod titanium dioxide by electrochemical deposition

[0044] Weigh 1g potassium fluoride, 20g ethanol, and 60g deionized water and mix them evenly to prepare an electrolyte, then drop 5% nitric acid into the electrolyte to adjust the pH to 5, use a titanium wire with a length of 100mm and a diameter of 3mm as a working electrode, a platinum electrode with a diameter of 12mm and a length of 120mm (model 213 / 213-01) as a counter electrode, and a saturated calomel electrode with a diameter of 5mm and a length of 50mm (model 232 / 232-01) as a reference electrode, then add the electrolyte to a glass electrolytic cell and fix the three electrodes in the electrolytic cell, place the electrolytic cell in a 35°C water bath, electrolyze for 6h at a current of 8mA during the water bath, scrape off the titanium dioxide on the surface of the titanium electrode after the deposition is completed, dry it at 90°C for 6h, and then place it in a muffle furnace and calcine it at 500°C for 3h to obtain micro-rod titanium dioxide;

[0045] (2) Preparation of nanoneedle active components by magnetic field-induced solvothermal method

[0046] Weigh 2g of cerium chloride, 3.68g of ferric chloride hexahydrate, 4g of citric acid monohydrate, and 160g of deionized water and mix them evenly to prepare a precursor solution, then drip a 15% sodium hydroxide solution into the precursor solution to adjust the pH to 8, then pour it into a hydrothermal reactor, then wrap 150 turns of 3mm copper wire around the outside of the hydrothermal reactor, and then place the hydrothermal reactor wrapped with copper wire in an oil bath pot added with dimethyl sulfoxide, and heat it in an oil bath at 150°C for a solvothermal reaction for 9h. During the solvothermal reaction, connect both ends of the copper wire to a 20V DC power supply, apply voltage to form an external magnetic field, filter after the reaction, dry at 90°C for 6h, and place it in a muffle furnace at 550°C for 3h to obtain a nanoneedle composite oxide of cerium oxide and ferroferric oxide;

[0047] (3) Microwave-assisted preparation of catalysts

[0048] 13.4 g of the microrod titanium dioxide obtained in step (1), 1 g of the nanoneedle composite oxide obtained in step (2), and 60 g of deionized water were mixed evenly, and then placed in a microwave sintering furnace for 2 h under 200 W ultrasonic oscillation, and sintered for 1 h under 1.5 kW microwave heating to obtain a catalyst (based on the mass of the carrier, the mass percentage of the active component is 7.46%, and the mass ratio of cerium oxide to ferrosoferric oxide in the active component is 1:0.75);

[0049] (4) Catalytic activity test

[0050] The experimental conditions for evaluating the activity of the catalyst of the present invention are as follows: 1 mL of a 20-40 mesh catalyst is poured into a quartz tube with an inner diameter of 6 mm, fixed with quartz wool and wire mesh, and the quartz tube is placed in a tube furnace. The actual temperature of the catalytic reaction is adjusted by controlling the heating temperature of the tube furnace. Intake gas components: NO (500 ppm), NH 3(500ppm), O 2 (11 vol.%), chlorobenzene (400 ppm), SO 2 (200ppm), the rest are N 2 The total gas flow rate was 500 mL / min, the temperature was controlled at 120-240°C, and it stayed stable for 30 min every 30°C. The chlorobenzene concentration was determined by gas chromatography, and the NO concentration was determined by flue gas analyzer. In the temperature range of 180-240°C, the catalyst dechlorobenzene efficiency and denitrification efficiency were both higher than 90%.

[0051] Example 3

[0052] (1) Preparation of microrod titanium dioxide by electrochemical deposition

[0053] Weigh 1g potassium fluoride, 40g ethanol, and 80g deionized water and mix them evenly to prepare an electrolyte, then add nitric acid with a mass fraction of 10% to the electrolyte to adjust the pH to 6, use a titanium wire with a length of 70mm and a diameter of 4mm as a working electrode, a platinum electrode with a diameter of 12mm and a length of 120mm (model 213 / 213-01) as a counter electrode, and a saturated calomel electrode with a diameter of 5mm and a length of 50mm (model 232 / 232-01) as a reference electrode, then add the electrolyte to a glass electrolytic cell and fix the three electrodes in the electrolytic cell, place the electrolytic cell in a 40°C water bath, electrolytically deposit at a current of 10mA for 8h during the water bath, scrape off the titanium dioxide on the surface of the titanium electrode after the deposition is completed, dry at 100°C for 8h, and then place it in a muffle furnace and calcine at a high temperature of 600°C for 4h to obtain micro-rod titanium dioxide;

[0054] (2) Preparation of nanoneedle active components by magnetic field-induced solvothermal method

[0055] Weigh 2g of cerium nitrate hexahydrate, 4.15g of ferric nitrate nonahydrate, 6g of citric acid monohydrate, and 200g of deionized water, mix them evenly to prepare a precursor solution, then drip a 20% sodium hydroxide solution into the precursor solution to adjust the pH to 9, then pour it into a hydrothermal reactor, then wrap 200 turns of 3mm copper wire around the outside of the hydrothermal reactor, and then place the hydrothermal reactor wrapped with copper wire in an oil bath pot added with dimethyl sulfoxide, and heat it in an oil bath at 160°C for a solvothermal reaction for 12h. During the solvothermal reaction, connect both ends of the copper wire to a 30V DC power supply, apply voltage to form an external magnetic field, filter after the reaction, dry at 100°C for 8h, and place it in a muffle furnace at 600°C for 4h to obtain a nanoneedle composite oxide of cerium oxide and ferrosoferric oxide;

[0056] (3) Microwave-assisted preparation of catalysts

[0057] 10 g of the microrod titanium dioxide obtained in step (1), 1 g of the nanoneedle composite oxide obtained in step (2), and 40 g of deionized water were mixed evenly, and then placed in a microwave sintering furnace for 2 h under 300 W ultrasonic oscillation, and sintered for 1 h under 1.5 kW microwave heating to obtain a catalyst (based on the mass of the carrier, the mass percentage of the active component is 10%, and the mass ratio of cerium oxide to ferrosoferric oxide in the active component is 1:1);

[0058] (4) Catalytic activity test

[0059] The experimental conditions for evaluating the activity of the catalyst of the present invention are as follows: 1 mL of a 20-40 mesh catalyst is poured into a quartz tube with an inner diameter of 6 mm, fixed with quartz wool and wire mesh, and the quartz tube is placed in a tube furnace. The actual temperature of the catalytic reaction is adjusted by controlling the heating temperature of the tube furnace. Intake gas components: NO (500 ppm), NH 3 (500ppm), O 2 (11 vol.%), chlorobenzene (400 ppm), SO 2 (200ppm), the rest are N 2 The total gas flow rate was 500 mL / min, the temperature was controlled at 120-240°C, and it stayed stable for 30 min every 30°C. The chlorobenzene concentration was determined by gas chromatography, and the NO concentration was determined by flue gas analyzer. In the temperature range of 180-240°C, the catalyst dechlorobenzene efficiency and denitrification efficiency were both higher than 90%.

[0060] Comparative Example 1

[0061] (1) Catalyst preparation

[0062] Except that the copper wire was not used to wind the hydrothermal reactor during catalyst preparation, other conditions were the same as those in Example 1;

[0063] (2) Catalytic activity test

[0064] Take 1 mL of 20-40 mesh catalyst, pour it into a quartz tube with an inner diameter of 6 mm, fix it with quartz wool and wire mesh, put 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), NH 3 (500ppm), O 2 (11 vol.%), chlorobenzene (400 ppm), SO 2 (200ppm), the rest are N 2 The total gas flow rate was 500 mL / min, the temperature was controlled at 120-240°C, and the temperature was kept stable for 30 min at every 30°C. The chlorobenzene concentration was determined by gas chromatography, and the NO concentration was determined by flue gas analyzer. At 180°C, the catalyst dechlorobenzene efficiency was 46.3%, and the denitrification efficiency was 52.8%;

[0065] (3) Contrast effect

[0066] Compared with Example 1, the catalyst was prepared without using copper wire to wind the hydrothermal reactor, that is, the magnetic field was not used to induce the formation of nanoneedles during the solvent thermal reaction process, and its active components generated nanoparticles under hydrothermal conditions ( Figure 2 ), the reaction energy barrier is higher, resulting in a significant decrease in catalytic activity.

Claims

1. A low-temperature rare earth-based denitration and dechlorobenzene catalyst, characterized in that: The catalyst uses micron-rod titanium dioxide as a carrier and nano-needle composite oxide of cerium oxide and ferroferric oxide as an active component, and is prepared by a combined method of electrochemical deposition and magnetic field induced solvent thermal. The mass percentage of the active component is 5-10% based on the mass of the carrier, and the mass ratio of cerium oxide to ferroferric oxide in the active component is 1:(0.5-1).

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 microrod titanium dioxide by electrochemical deposition Weigh potassium fluoride, ethanol, and deionized water and mix them evenly to prepare an electrolyte, then drop nitric acid into the electrolyte to adjust the pH, use a titanium wire as a working electrode, a platinum electrode as a counter electrode, and a saturated calomel electrode as a reference electrode, then add the electrolyte into a glass electrolytic cell and fix the three electrodes in the electrolytic cell, place the electrolytic cell in a water bath, pass current during the water bath to perform electrolytic deposition, scrape off the titanium dioxide on the surface of the titanium electrode after the deposition is completed, dry it, and then place it in a muffle furnace for high-temperature roasting to obtain micro-rod titanium dioxide; (2) Preparation of nanoneedle active components by magnetic field-induced solvothermal method A cerium source, an iron source, a reducing agent, and deionized water are weighed and mixed evenly to prepare a precursor solution, and then a sodium hydroxide solution is added to the precursor solution to adjust the alkalinity, and then the precursor solution is poured into a hydrothermal reactor, and then a copper wire is wound around the outside of the hydrothermal reactor, and then the hydrothermal reactor with the copper wire wound is placed in an oil bath pot, and the oil bath is heated to perform a solvent thermal reaction, and at the same time of the solvent thermal reaction, both ends of the copper wire are connected to a DC power supply, and a voltage is applied to form an external magnetic field, and after the reaction is completed, the solution is filtered and dried, and then placed in a muffle furnace for calcination to obtain a nano-needle composite oxide of cerium oxide and ferroferric oxide; (3) Microwave-assisted preparation of catalysts The micron-rod titanium dioxide obtained in step (1), the nano-needle composite oxide obtained in step (2) and deionized water are uniformly mixed, placed in a microwave sintering furnace after ultrasonic oscillation, and sintered by microwave heating to obtain a catalyst.

3. The preparation method according to claim 1, characterized in that: The mass ratio of potassium fluoride, ethanol and deionized water in step (1) is 1: (20-40): (60-80), and the pH value of the electrolyte is 3-6.

4. The preparation method according to claim 2, characterized in that: The titanium wire described in step (1) is a titanium metal wire with a length of 50 to 100 mm and a diameter of 3 to 5 mm; the counter electrode is a platinum electrode, model 213 / 213-01, a diameter of 12 mm, and a length of 120 mm; the reference electrode is a saturated calomel electrode, model 232 / 232-01, a diameter of 5 mm, and a length of 50 mm.

5. The preparation method according to claim 1, characterized in that: The temperature of the water bath described in step (1) is 25-40°C, the current passed is 5-10mA, and the electrolytic deposition time is 4-8h; the drying temperature is 80-100°C, and the drying time is 4-8h; the high-temperature calcination temperature is 400-600°C, and the high-temperature calcination time is 2-4h.

6. The preparation method according to claim 2, characterized in that: The cerium source described in step (2) is cerium chloride or cerium nitrate hexahydrate, the iron source is ferric chloride hexahydrate or ferric nitrate nonahydrate, and the reducing agent is citric acid monohydrate or ethylene glycol; the mass ratio of the cerium source, the reducing agent, and deionized water is 1: (1-3): (60-100), and the alkaline pH is adjusted to 8-9.

7. The preparation method according to claim 2, characterized in that: The diameter of the copper wire described in step (2) is 2-3 mm, the number of turns wound is 100-200 turns, the solvent in the oil bath pot is dimethyl sulfoxide, the temperature of the oil bath heating is 140-160° C., and the oil bath heating time is 6-12 h; the applied voltage is 10-30 V; the drying temperature is 80-100° C., and the drying time is 4-8 h; the roasting temperature is 500-600° C., and the roasting time is 2-4 h.

8. The preparation method according to claim 2, characterized in that: The mass ratio of the microrod titanium dioxide to deionized water in step (3) is 1:(40-80); the power of the ultrasonic oscillation is 150-300W, and the time of the ultrasonic oscillation is 1-2h; the power of the microwave heating sintering is 1.0-1.5kW, and the time of the microwave heating sintering is 0.5-1h.

9. Application of the catalyst according to claim 1 in denitration and dechlorobenzene removal of complex flue gas in non-power industries.

10. The non-electricity industry described in claim 9 specifically refers to steel sintering, dry cement and chemical industries.

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