A porous environmental catalytic material and a preparation method and application thereof
By preparing porous catalytic materials supported by titanium dioxide and iron oxide composite oxides, the problems of high-temperature deactivation and insufficient low-temperature activity of existing catalysts were solved, realizing an efficient and environmentally friendly soil thermal desorption process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NANJING TECH UNIV
- Filing Date
- 2026-03-24
- Publication Date
- 2026-06-23
AI Technical Summary
Existing soil thermal desorption catalysts suffer from problems such as high-temperature sintering deactivation of active components, poor compatibility with soil matrix, and insufficient low-temperature activity, resulting in high energy consumption and environmental unfriendliness of thermal desorption technology.
A porous catalytic material was prepared using a composite oxide of titanium dioxide and iron oxide as a carrier and cerium oxide as the active component. The method employed was a combination of biological template confined impregnation, molten salt-assisted confined crystallization, and Fenton reagent-assisted etching to ensure uniform component distribution and high activity.
The prepared catalytic material has high activity, good thermal stability and soil compatibility, which reduces thermal desorption energy consumption, improves pollutant desorption and degradation efficiency, and avoids the generation of secondary pollutants.
Smart Images
Figure CN122252271A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a porous environmental catalytic material, its preparation method, and its application, belonging to the field of soil remediation. Background Technology
[0002] Studies have shown that adding appropriate amounts of catalysts to contaminated soil can leverage its oxygen vacancies and high porosity to achieve efficient desorption and degradation of pollutants at lower temperatures. The introduction of catalysts not only lowers the activation energy and shortens the desorption time, but also promotes the oxidative decomposition of pollutants through the generation of reactive oxygen species, preventing the formation of secondary pollutants. However, current catalyst systems suitable for soil thermal desorption processes are still immature, suffering from problems such as high-temperature sintering deactivation of active components, poor compatibility with soil matrices, and insufficient activity at low temperatures. Therefore, developing novel catalytic materials that combine high activity, high thermal stability, and good soil compatibility is of great significance for promoting energy conservation, emission reduction, and green sustainable development in thermal desorption technology. Summary of the Invention
[0003] The purpose of this invention is to address the current status and existing problems of soil thermal desorption by proposing a porous environmental catalytic material, its preparation method, and its application.
[0004] A porous environmental catalytic material is characterized in that: the catalytic material uses a composite oxide of titanium dioxide and iron oxide as a support, cerium oxide as the active component, and is prepared by a combined method of biological template confined impregnation-molten salt-assisted confined crystallization-Fenton reagent-assisted etching; wherein, based on the mass of the support, the mass percentage of the active component is 5~10%, and the mass ratio of titanium dioxide to iron oxide in the support is 1:(0.5~2).
[0005] A method for preparing the above-mentioned catalytic material, the method of which is as follows:
[0006] (1) Preparation of composite templates by confined impregnation with biological templates
[0007] The dried loofah sponge was cut into regular blocks and placed in sodium hydroxide solution for constant temperature treatment. After constant temperature treatment, it was washed with deionized water, then placed in hydrogen peroxide solution and the pH was adjusted with ammonia. After ultrasonic treatment, it was washed with deionized water. Then it was immersed in ethanol solutions of different concentrations in turn, and finally placed in a vacuum drying oven for low temperature drying to obtain the pretreated loofah sponge template.
[0008] Weigh out titanium source, iron source, cerium source, ethylene glycol methyl ether, acetylacetone, acetic acid, and polyether F127, mix them evenly to form a precursor solution, and place it in a vacuum filtration flask. Then, place the loofah template in the precursor solution, evacuate and let it stand, then sonicate it, and finally dry it in an oven to obtain a composite template.
[0009] (2) Preparation of composite oxides by molten salt-assisted confined crystallization
[0010] The composite template, sodium chloride, potassium chloride, and oxalic acid obtained in step (1) are ground and mixed, and then placed in a tube furnace. Under the condition of nitrogen gas, the temperature is raised to 700~800℃ and held for 1~2 hours. After naturally cooling to room temperature, the temperature is raised to 500~600℃ and held for 1~2 hours under the condition of oxygen gas to obtain the composite oxide.
[0011] (3) Preparation of catalyst by Fenton reagent-assisted etching
[0012] The composite oxide obtained in step (2) was immersed in Fenton's reagent and ultrasonically treated. After ultrasonic treatment, it was filtered, washed with deionized water, and dried to obtain the catalyst.
[0013] In the above method: the dried loofah sponge mentioned in step (1) was purchased from Guangxi Huajinhui Agricultural Development Co., Ltd., and cut into regular blocks with a size of (2~4)cm×(2~4)cm×(1~2)cm. The mass fraction of the sodium hydroxide solution was 5~10%, and the mass ratio of the dried loofah sponge cut into regular blocks to the sodium hydroxide solution was 1:(20~40). The temperature of the constant temperature treatment was 60~80℃, and the time of the constant temperature treatment was 2~4h.
[0014] In the above method: the mass fraction of hydrogen peroxide solution in step (1) is 3~6%, the mass ratio of dried loofah sponge cut into regular blocks to hydrogen peroxide solution is 1:(10~20), the pH is adjusted to 8~9 with ammonia water, the power of ultrasonic treatment is 100~200W, and the ultrasonic treatment time is 1~2h.
[0015] In the above method: the mass fraction of the ethanol solutions of different concentrations mentioned in step (1) is 50%, 75% and 100%, and the immersion time is 20~40 min for each. The low temperature drying temperature is 50~60℃ and the low temperature drying time is 12~24 h.
[0016] In the above method: the titanium source in step (1) is tetrabutyl titanate or tetraethyl titanate, the iron source is ferric nitrate nonahydrate or ferric chloride hexahydrate, the cerium source is cerium nitrate hexahydrate or cerium chloride, and the mass ratio of titanium source, ethylene glycol methyl ether, acetylacetone, acetic acid, polyether F127 and loofah template is 1:(20~40):(5~10):(1~3):(0.5~1):(5~10). After standing for 1~2 hours, the ultrasonic treatment power is 100~200W, the ultrasonic treatment time is 20~40min, the drying temperature is 50~60℃, and the drying time is 12~24h.
[0017] In the above method: the mass ratio of the composite template, sodium chloride, potassium chloride and oxalic acid in step (2) is 1:(1~2):(1~2):(0.05~0.1), the nitrogen gas is introduced at a rate of 20~40 mL / min, and the oxygen gas is introduced at a rate of 20~40 mL / min.
[0018] In the above method: the Fenton reagent mentioned in step (3) is an aqueous solution of 0.1 mM ferrous sulfate and 3% H2O2, the mass ratio of the composite oxide to the Fenton reagent is 1:(10~20), the ultrasonic treatment power is 100~200W, and the ultrasonic treatment time is 5~10min.
[0019] The catalyst prepared by the above method is used in the thermal desorption of organic polluted soil.
[0020] In the technical solution of this invention: the above-mentioned organic compound is chlorobenzene.
[0021] The thermal desorption experimental conditions and results of the present invention: 10g of soil containing 5% chlorobenzene was loaded into the catalyst performance evaluation reaction device. The inner diameter of the quartz tube in the evaluation reaction device was 10mm. The soil heating temperature and hot air temperature were 80~120℃. The amount of catalyst used was 1g. After thermal desorption at 100°C for 10min, the desorption effect of chlorobenzene could reach 100%.
[0022] Beneficial effects:
[0023] (1) To avoid the problem that conventional simple cleaning or acid-base treatment is insufficient to completely remove the wax layer and impurities on the surface of natural biological templates, resulting in poor wettability and uneven loading of the precursor solution, this invention adopts a four-step pretreatment process: alkaline heat treatment degreasing, hydrogen peroxide bleaching, ultrasonic-assisted etching, and gradient solvent replacement. The saponification reaction of sodium hydroxide thoroughly removes the hydrophobic lipids on the fiber surface, and the mild oxidation of lignin in an ammonia buffer system by hydrogen peroxide decomposes the lignin. Simultaneously, the ultrasonic cavitation effect generates nanoscale etching points on the fiber surface, significantly increasing the specific surface area and surface hydroxyl density of the template. To avoid the problem of uneven component loading on the biological template caused by conventional impregnation methods, this invention combines vacuum-assisted impregnation with ultrasonic treatment. In this invention, air is removed from the micron-sized pores of the template through a vacuum environment, allowing the precursor solution to penetrate into the pores under pressure difference. High-frequency vibration, achieved through ultrasonic treatment, promotes uniform spreading of the solution on the fiber surface and prevents precursor precipitation due to localized oversaturation. Furthermore, the invention simultaneously introduces acetylacetone and acetic acid as dual coordinating agents into the precursor solution, forming a stable chelate with the titanium source. This inhibits the severe hydrolysis of the titanium source, ensuring uniform mixing of metal ions at the molecular level, and forming a continuous amorphous gel film encapsulating the fiber surface after drying. This process preserves the three-dimensional interconnected macroporous framework of the biological template while achieving high dispersion of components on the framework surface, laying the foundation for uniform growth of nanoparticles during subsequent crystallization.
[0024] (2) In order to avoid the problem that the precursor is directly decomposed by heat in the gas phase environment during conventional high-temperature solid-phase calcination, and that nanoparticles are prone to surface diffusion and sintering growth, resulting in coarsening of grain size and a sharp decrease in specific surface area, the present invention adopts a molten salt-assisted confined crystallization strategy. By introducing a NaCl-KCl eutectic salt system, a liquid phase reaction medium is formed at high temperature. The metal oxide precursor dissolves and precipitates in the molten salt and completes the crystallization process. The liquid phase environment of the molten salt has a confining effect on grain growth: on the one hand, the high viscosity of the molten salt surrounds the crystal nucleus, increases the activation energy of ion diffusion, and inhibits Ostwald ripening; on the other hand, the space occupied by the molten salt is washed out and transformed into mesopores in the subsequent process. In addition, the present invention completes the oxide crystallization in a nitrogen atmosphere and uses H2 and CO generated by the decomposition of oxalic acid to partially reduce the iron species to Fe3O4, avoiding the direct generation of Fe2O3 in an air atmosphere and then switching to an oxygen atmosphere for low-temperature treatment. This ensures the full development of CeO2 lattice and prevents the over-oxidation of Fe3O4.
[0025] (3) To further enhance the low-temperature catalytic performance, this invention employs Fenton reagent-assisted etching to strengthen the catalyst. This is achieved by using Fenton reagent (Fe...) 2+The hydroxyl radicals generated by Fenton's reagent at room temperature etch the catalyst surface, exposing more active crystal faces and oxygen vacancies. Simultaneously, the cavitation effect of ultrasound generates localized instantaneous high temperature and pressure, promoting the decomposition of H2O2 to generate more free radicals and enhancing the mass transfer process of Fenton's reagent within the material's pores, thereby increasing the hydroxyl concentration on the catalyst surface. Furthermore, the acidic environment (Fe2O3 / H2O2) in Fenton's reagent... 2+ Hydrolysis produces a weak acid, which can elute molten salts. Na + K + Cl - The plasma dissolves and diffuses in the liquid phase and is removed by subsequent cleaning steps;
[0026] Therefore, the catalytic material prepared by this invention is environmentally friendly, has a simple preparation process, low cost, and high cost-effectiveness. It also has advantages such as large specific surface area and sufficient exposure of active sites, which can reduce the energy consumption of soil thermal desorption and reduce the cost of industrial thermal desorption, and has strong application and promotion value. Attached Figure Description
[0027] Figure 1 The image shows a scanning electron microscope (SEM) image of the catalyst prepared in Example 1.
[0028] Figure 2 The graph shows the performance of the catalysts prepared in Examples 1-3 in removing chlorobenzene. Detailed Implementation
[0029] The present invention will be further described below with reference to the embodiments. The embodiments are implemented under the premise of the technical solution of the present invention, and detailed implementation methods and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments.
[0030] Example 1
[0031] (1) Preparation of composite templates by confined impregnation with biological templates
[0032] Dried loofah sponge (purchased from Guangxi Huajinhui Agricultural Development Co., Ltd.) was cut into regular blocks (2cm×2cm×1cm). Then, 20 blocks of dried loofah sponge (total mass 8g) were placed in 160g of 5% sodium hydroxide solution and treated at 60℃ for 4h. After the constant temperature treatment, they were washed with deionized water and then placed in 80g of 3% hydrogen peroxide solution. The pH was adjusted to 8 with ammonia water and ultrasonically treated (ultrasonic power of 100W, ultrasonic treatment time of 2h). After washing with deionized water, they were then immersed in 100g of 50%, 75%, and 100% ethanol solutions (immersion time of 20min for each solution). Finally, they were placed in a vacuum drying oven and dried at 50℃ for 24h to obtain the pretreated loofah sponge template.
[0033] Weigh out 1g tetrabutyl titanate, 0.614g ferric nitrate nonahydrate, 44.4mg cerium nitrate hexahydrate, 20g ethylene glycol methyl ether, 5g acetylacetone, 1g acetic acid, and 0.5g polyether F127, mix them evenly to form a precursor solution, and place it in a vacuum filtration flask. Then, place 5g of loofah template in the precursor solution, evacuate the vacuum flask, let it stand for 2 hours, and then sonicate it (the power of the sonication treatment is 100W, and the time of the sonication treatment is 40min). Finally, place it in an oven at 50℃ and dry it for 24 hours to obtain the composite template.
[0034] (2) Preparation of composite oxides by molten salt-assisted confined crystallization
[0035] Weigh 6g of the composite template obtained in step (1), 6g of sodium chloride, 6g of potassium chloride, and 0.3g of oxalic acid, grind and mix them, and then place them in a tube furnace. Under the condition of nitrogen gas (the rate of nitrogen gas introduction is 20mL / min), heat to 700℃ and hold for 2h. After naturally cooling to room temperature, under the condition of oxygen gas introduction (the rate of oxygen gas introduction is 20mL / min), heat to 500℃ and hold for 2h to obtain the composite oxide.
[0036] (3) Preparation of catalyst by Fenton reagent-assisted etching
[0037] 0.3g of the composite oxide prepared in step (2) was immersed in 3g of Fenton's reagent (an aqueous solution of 0.1 mM ferrous sulfate and 3% H2O2) and ultrasonically treated (the ultrasonic power was 100W and the ultrasonic treatment time was 10min). After ultrasonic treatment, the mixture was filtered, washed with deionized water, and dried to obtain the catalyst (based on the mass of the support, the mass percentage of the active component was 5%, and the mass ratio of titanium dioxide to iron oxide in the support was 1:0.5; the scanning electron microscope image of the catalyst is shown below). Figure 1 (as shown)
[0038] (4) Catalytic activity test
[0039] Take 10g of soil containing 5% chlorobenzene and put it into the catalyst performance evaluation reaction device. The inner diameter of the quartz tube in the evaluation reaction device is 10mm. The soil heating temperature and hot air temperature are 80~120℃. The amount of catalyst used is 1g. After thermal desorption at 100°C for 10min, the desorption effect of chlorobenzene can reach 100%.
[0040] Example 2
[0041] (1) Preparation of composite templates by confined impregnation with biological templates
[0042] Dried loofah sponge (purchased from Guangxi Huajinhui Agricultural Development Co., Ltd.) was cut into regular blocks (3cm×3cm×1cm). Ten blocks of dried loofah sponge (total mass 9g) were then placed in 270g of a 7% sodium hydroxide solution and treated at 70℃ for 3 hours. After the treatment, the blocks were washed with deionized water and then placed in 135g of a 5% hydrogen peroxide solution. The pH was adjusted to 9 with ammonia and ultrasonically treated (ultrasonic power 150W, ultrasonic treatment time 1.5h). After washing with deionized water, the blocks were then immersed in 100g of 50%, 75%, and 100% ethanol solutions (immersion time 30min each). Finally, the blocks were dried in a vacuum drying oven at 55℃ for 18h to obtain a pretreated loofah sponge template.
[0043] Weigh out 1g tetraethyl titanate, 1.833g ferric nitrate nonahydrate, 123.7mg cerium nitrate hexahydrate, 30g ethylene glycol methyl ether, 7g acetylacetone, 2g acetic acid, and 0.7g polyether F127, mix them evenly to form a precursor solution, and place it in a vacuum filtration flask. Then, place 7g of loofah template in the precursor solution, evacuate the vacuum, let it stand for 1.5h, and then sonicate it (the power of the sonication treatment is 150W, and the time of the sonication treatment is 30min). Finally, place it in an oven at 55℃ for 18h to dry, and obtain the composite template.
[0044] (2) Preparation of composite oxides by molten salt-assisted confined crystallization
[0045] Weigh 8g of the composite template obtained in step (1), 12g of sodium chloride, 12g of potassium chloride, and 0.56g of oxalic acid, grind and mix them, and then place them in a tube furnace. Under the condition of nitrogen gas (the rate of nitrogen gas introduction is 30mL / min), heat to 750℃ and hold for 1.5h. After naturally cooling to room temperature, under the condition of oxygen gas introduction (the rate of oxygen gas introduction is 30mL / min), heat to 550℃ and hold for 1.5h to obtain the composite oxide.
[0046] (3) Preparation of catalyst by Fenton reagent-assisted etching
[0047] The composite oxide prepared in step (2) was immersed in 7.5g of Fenton's reagent (an aqueous solution of 0.1 mM ferrous sulfate and 3% H2O2) and ultrasonically treated (the ultrasonic power was 150W and the ultrasonic treatment time was 7min). After ultrasonic treatment, the mixture was filtered, washed with deionized water, and dried to obtain the catalyst (based on the mass of the support, the mass percentage of the active component was 7%, and the mass ratio of titanium dioxide to iron oxide in the support was 1:1).
[0048] (4) Catalytic activity test
[0049] Take 10g of soil containing 5% chlorobenzene and put it into the catalyst performance evaluation reaction device. The inner diameter of the quartz tube in the evaluation reaction device is 10mm. The soil heating temperature and hot air temperature are 80~120℃. The amount of catalyst used is 1g. After thermal desorption at 100°C for 10min, the desorption effect of chlorobenzene can reach 100%.
[0050] Example 3
[0051] (1) Preparation of composite templates by confined impregnation with biological templates
[0052] Dried loofah sponge (purchased from Guangxi Huajinhui Agricultural Development Co., Ltd.) was cut into regular blocks (4cm×4cm×2cm). Five blocks of dried loofah sponge (total mass 16g) were then placed in 640g of a 10% sodium hydroxide solution and treated at 80℃ for 2 hours. After the treatment, the blocks were washed with deionized water and then placed in 320g of a 6% hydrogen peroxide solution. The pH was adjusted to 9 with ammonia and ultrasonically treated (ultrasonic power 200W, ultrasonic treatment time 1 hour). After washing with deionized water, the blocks were then immersed in 100g of 50%, 75%, and 100% ethanol solutions (immersion time 40min for each solution). Finally, the blocks were dried in a vacuum drying oven at 60℃ for 12 hours to obtain a pretreated loofah sponge template.
[0053] Weigh out 1g tetraethyl titanate, 2.452g ferric chloride hexahydrate, 150.4mg cerium chloride, 40g ethylene glycol methyl ether, 10g acetylacetone, 3g acetic acid, and 1g polyether F127, mix them evenly to form a precursor solution, and place it in a vacuum filtration flask. Then, place 10g of loofah template in the precursor solution, evacuate the vacuum flask, let it stand for 1 hour, and then sonicate it (the power of the sonication treatment is 200W, and the time of the sonication treatment is 20min). Finally, place it in an oven at 60℃ for 12 hours to dry, and obtain the composite template.
[0054] (2) Preparation of composite oxides by molten salt-assisted confined crystallization
[0055] Weigh 12g of the composite template obtained in step (1), 24g of sodium chloride, 24g of potassium chloride, and 1.2g of oxalic acid, grind and mix them, and then place them in a tube furnace. Under the condition of nitrogen gas (the rate of nitrogen gas introduction is 40mL / min), heat to 800℃ and hold for 1h. After naturally cooling to room temperature, under the condition of oxygen gas introduction (the rate of oxygen gas introduction is 40mL / min), heat to 600℃ and hold for 1h to obtain the composite oxide.
[0056] (3) Preparation of catalyst by Fenton reagent-assisted etching
[0057] 1g of the composite oxide prepared in step (2) was immersed in 20g of Fenton's reagent (an aqueous solution of 0.1 mM ferrous sulfate and 3% H2O2) and ultrasonically treated (the ultrasonic power was 200W and the ultrasonic treatment time was 5min). After ultrasonic treatment, the mixture was filtered, washed with deionized water, and dried to obtain the catalyst (based on the mass of the support, the mass percentage of the active component was 10%, and the mass ratio of titanium dioxide and iron oxide in the support was 1:2).
[0058] (4) Catalytic activity test
[0059] Take 10g of soil containing 5% chlorobenzene and put it into the catalyst performance evaluation reaction device. The inner diameter of the quartz tube in the evaluation reaction device is 10mm. The soil heating temperature and hot air temperature are 80~120℃. The amount of catalyst used is 1g. After thermal desorption at 100°C for 10min, the desorption effect of chlorobenzene can reach 100%.
Claims
1. A porous environmental catalytic material, wherein the catalytic material uses a composite oxide of titanium dioxide and iron oxide as a support, cerium oxide as the active component, and is prepared by a combined method of biological template confined impregnation-molten salt-assisted confined crystallization-Fenton reagent-assisted etching; wherein, Based on the carrier mass, the active component has a mass percentage of 5-10%, and the mass ratio of titanium dioxide to iron oxide in the carrier is 1:(0.5-2).
2. A method for preparing the catalytic material according to claim 1, characterized in that: The preparation method of this catalytic material is as follows: (1) Preparation of composite templates by confined impregnation with biological templates The dried loofah sponge was cut into regular blocks and placed in sodium hydroxide solution for constant temperature treatment. After constant temperature treatment, it was washed with deionized water, then placed in hydrogen peroxide solution and the pH was adjusted with ammonia. After ultrasonic treatment, it was washed with deionized water. Then it was immersed in ethanol solutions of different concentrations in turn, and finally placed in a vacuum drying oven for low temperature drying to obtain the pretreated loofah sponge template. Weigh out titanium source, iron source, cerium source, ethylene glycol methyl ether, acetylacetone, acetic acid, and polyether F127, mix them evenly to form a precursor solution, and place it in a vacuum filtration flask. Then, place the loofah template in the precursor solution, evacuate and let it stand, then sonicate it, and finally dry it in an oven to obtain a composite template. (2) Preparation of composite oxides by molten salt-assisted confined crystallization The composite template, sodium chloride, potassium chloride, and oxalic acid obtained in step (1) are ground and mixed, and then placed in a tube furnace. Under the condition of nitrogen gas, the temperature is raised to 700~800℃ and held for 1~2 hours. After naturally cooling to room temperature, the temperature is raised to 500~600℃ and held for 1~2 hours under the condition of oxygen gas to obtain the composite oxide. (3) Preparation of catalyst by Fenton reagent-assisted etching The composite oxide obtained in step (2) was immersed in Fenton's reagent and ultrasonically treated. After ultrasonic treatment, it was filtered, washed with deionized water, and dried to obtain the catalyst.
3. The preparation method according to claim 2, characterized in that: The dried loofah sponge mentioned in step (1) is cut into regular blocks with a size of (2~4)cm×(2~4)cm×(1~2)cm. The mass fraction of the sodium hydroxide solution is 5~10%. The mass ratio of the dried loofah sponge cut into regular blocks to the sodium hydroxide solution is 1:(20~40). The constant temperature treatment temperature is 60~80℃ and the constant temperature treatment time is 2~4h.
4. The preparation method according to claim 2, characterized in that: The mass fraction of the hydrogen peroxide solution mentioned in step (1) is 3~6%, the mass ratio of the dried loofah sponge cut into regular blocks to the hydrogen peroxide solution is 1:(10~20), the pH is adjusted to 8~9 with ammonia water, the power of ultrasonic treatment is 100~200W, and the ultrasonic treatment time is 1~2h.
5. The preparation method according to claim 2, characterized in that: The ethanol solutions of different concentrations mentioned in step (1) have mass fractions of 50%, 75% and 100%, and are immersed for 20 to 40 minutes in sequence. The temperature for low-temperature drying is 50 to 60°C and the drying time is 12 to 24 hours.
6. The preparation method according to claim 2, characterized in that: The titanium source mentioned in step (1) is tetrabutyl titanate or tetraethyl titanate, the iron source is ferric nitrate nonahydrate or ferric chloride hexahydrate, the cerium source is cerium nitrate hexahydrate or cerium chloride, and the mass ratio of titanium source, ethylene glycol methyl ether, acetylacetone, acetic acid, polyether F127 and loofah template is 1:(20~40):(5~10):(1~3):(0.5~1):(5~10). After standing for 1~2 hours, the ultrasonic treatment power is 100~200W, the ultrasonic treatment time is 20~40min, the drying temperature is 50~60℃, and the drying time is 12~24h.
7. The preparation method according to claim 2, characterized in that: The mass ratio of the composite template, sodium chloride, potassium chloride and oxalic acid in step (2) is 1:(1~2):(1~2):(0.05~0.1), the nitrogen gas is introduced at a rate of 20~40 mL / min, and the oxygen gas is introduced at a rate of 20~40 mL / min.
8. The preparation method according to claim 2, characterized in that: The Fenton reagent mentioned in step (3) is an aqueous solution of 0.1 mM ferrous sulfate and 3% H2O2. The mass ratio of the composite oxide to the Fenton reagent is 1:(10~20). The ultrasonic treatment power is 100~200W and the ultrasonic treatment time is 5~10min.
9. The application of the catalyst according to claim 1 in the thermal desorption of organic polluted soil.
10. The application according to claim 9, characterized in that... The organic compound mentioned is chlorobenzene.