Superoxide catalytic oxidation catalyst and preparation method thereof

Abstract

The invention relates to the field of catalytic materials, in particular to a superoxide catalytic oxidation catalyst and a preparation method thereof. The method comprises the following steps: taking a titanium salt as a raw material, adding a fluorinating reagent and a dispersing solvent, mixing to obtain a substrate mixed solution, adjusting the pH value to alkalescence, and carrying out heat and pressure preservation reaction to obtain the superoxide catalytic oxidation catalyst through one-step synthesis. The sewage treatment agent can quickly and effectively decompose organic substances which are difficult to degrade in sewage, and has broad-spectrum and efficient disinfection and sterilization capability; by means of the excellent oxidation performance of active oxygen, bacteria and viruses can be widely and efficiently killed. In addition, the cost benefit is remarkable; compared with a traditional wastewater treatment method, the catalyst adopted by the method is lower in use cost, and the treatment time can be shortened due to the high efficiency characteristic of the catalyst, so that the overall operation cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of catalytic materials, and in particular to a superoxide catalytic oxidation catalyst and a preparation method thereof. Background Art

[0002] In today's sewage treatment technology field, many existing technical means are limited to achieving a single function, such as being able to only degrade organic matter in wastewater, or only being able to perform disinfection and remove microorganisms such as bacteria and viruses in wastewater. However, these single-function technologies often face difficult-to-overcome problems, such as the possibility of causing secondary pollution, or relatively low treatment efficiency, which makes it difficult to meet actual needs. Especially when treating wastewater containing multiple pollutants, the situation is even more complicated. For example, wastewater may contain multiple pollutants such as organic matter, bacteria, heavy metals, etc., and needs to be comprehensively treated through a series of complex treatment processes to ensure that the wastewater meets the discharge standards.

[0003] When dealing with biopharmaceutical wastewater that is difficult to degrade, such as antibiotics, there is currently a lack of an efficient and low-cost treatment technology. Such biopharmaceutical wastewater usually contains high concentrations of organic matter and difficult-to-decompose chemicals, making the treatment process more difficult. Therefore, in order to achieve efficient and harmless degradation and disinfection of wastewater, improve water resource utilization, and ensure environmental safety, the sewage treatment field urgently needs a safe and efficient degradation and disinfection solution that can treat special wastewater (such as pharmaceutical wastewater).

[0004] The solution needs to have multiple functions and be able to simultaneously treat multiple pollution factors, including organic matter, bacteria, heavy metals, etc., and be able to effectively degrade difficult-to-decompose chemical substances (such as antibiotics). In addition, the solution must also have a high treatment efficiency and be able to complete wastewater treatment in a relatively short period of time, reduce treatment costs, and ensure that the treated wastewater meets environmental discharge standards and does not cause secondary pollution to the environment. Summary of the invention

[0005] The technical solution of the present invention aims at the technical difficulties such as complex process and secondary pollution in the existing wastewater treatment process, and provides a superoxide catalytic oxidation catalyst and a preparation method thereof.

[0006] The main purpose of the present invention is: 1. Efficiently degrade the difficult-to-degrade organic matter in the sewage system; 2. It has extremely high oxidative activity and can kill bacteria, viruses and other microorganisms in the water system; 3. It is environmentally friendly and will not cause secondary pollution to the environment.

[0007] To achieve the above objectives, the present invention adopts the following technical solutions.

[0008] A method for preparing a superoxide catalytic oxidation catalyst, The method comprises: Titanium salt is used as a raw material, a fluorination agent and a dispersing solvent are added to mix as a base mixed solution, and the pH is adjusted to a weak alkaline state, and then the superoxide catalytic oxidation catalyst is synthesized in one step by heat preservation and pressure maintenance reaction.

[0009] As a preference, The titanium salt is titanium sulfate; The fluorination agent is hydrofluoric acid; The dispersing solvent is deionized water.

[0010] As a preference, The titanium salt, the fluorination agent and the dispersing solvent are mixed in a mass ratio of 1: (4.4-4.5): (17-23).

[0011] As a preference, The process of adjusting the pH to weak alkalinity is to adjust the pH value to 8-9 with ammonia water.

[0012] As a preference, The ammonia water is saturated ammonia water; The ammonia water is calculated based on the volume of the base mixed solution, and 7-13% VOL of the base mixed solution is added dropwise every minute.

[0013] As a preference, The heat preservation and pressure preservation reaction process is to react continuously for 2 to 4 hours under the conditions of an ambient pressure of 3 to 5 MPa and an ambient temperature of 40 to 50°C.

[0014] As a preference, After the heat preservation and pressure maintenance reaction is completed, the obtained superoxide catalytic oxidation catalyst is dried and then post-heat treated.

[0015] As a preference, The post-heat treatment process is: The superoxide catalytic oxidation catalyst is placed in a protective atmosphere, heated to 550-550°C at 2-3°C / min, and then kept at this temperature for 1.5-2.5 hours to effect a crystal phase transformation.

[0016] A superoxide catalytic oxidation catalyst.

[0017] In the technical scheme of the present invention, the core lies in the use of a liquid phase one-step synthesis method to prepare the catalyst material, and based on the synergistic effect of other structures of the catalyst, efficiently generate hydroxyl radicals and superoxide ions with high activity and strong oxidizing properties, which react rapidly with organic matter to achieve rapid and deep degradation of difficult-to-degrade organic pollutants in sewage, while damaging the cell walls and ultimately inactivating bacteria and virus particles in the wastewater to achieve disinfection.

[0018] In the technical solution of the present invention, the core parameters in the synthesis process, including pH value, reaction temperature and pressure, and subsequent heat treatment conditions are precisely controlled to ensure that the catalyst exhibits excellent high activity and stability. Titanium oxide, as a material, has a relatively wide band gap characteristic, which means that when it is irradiated with ultraviolet light, the electrons in the valence band can absorb the energy provided by the photons. These electrons then transition to the conduction band, thereby generating photogenerated electrons in the conduction band and photogenerated holes in the valence band. However, although this phenomenon has certain photocatalytic potential in theory, titanium oxide has some limitations in practical applications. Specifically, titanium oxide can only exhibit strong photocatalytic activity under ultraviolet light with a wavelength of less than 387 nm. Therefore, under the irradiation of daily visible light, the photocatalytic activity of titanium oxide is relatively poor, and the utilization rate of visible light is very limited. In addition, since photogenerated electrons and holes are easily compounded in titanium oxide, this compound process further limits its application range and efficiency as a catalyst. Therefore, although the photocatalytic performance of titanium oxide under ultraviolet light is promising, these limitations still need to be overcome in practical applications to give full play to its potential catalytic ability. In order to overcome the problem of insufficient catalytic activity of titanium oxide in the visible light region, the present invention first performs fluorination to adjust the band structure of titanium oxide, and secondly, by optimizing the morphology and structure of the catalyst, it is prepared into a nanostructure, increasing the specific surface area of ​​the catalyst, thereby providing more active sites, reducing the recombination probability of photogenerated electrons and holes, and further improving the catalytic efficiency of the catalyst. In addition, the fluorinated titanium oxide presents an anatase phase and shows a high degree of crystallization. With the subsequent heat treatment, it is also observed that the irregular clusters on the surface of the catalyst are in close contact with each other. This contact promotes the effective migration of the hole-electron pairs generated by light excitation, which is conducive to improving the efficiency and effectiveness of the photocatalytic reaction. After further comparative studies, when the titanium source is different during the preparation of the titanium oxide catalyst, the properties of the catalytic material finally prepared are also different. This is because the photocatalysis on titanium oxide has a variety of interfacial electron transfer modes, which will affect the oxygen vacancies and corresponding catalytic active centers formed during the subsequent heat treatment. In the process of wastewater degradation, the active sites rich in the surface of the catalyst can efficiently adsorb organic pollutants contained in the sewage, and then catalyze the generation of hydroxyl radicals and superoxide ions. These highly active species react with organic matter to oxidize it, effectively breaking down its chemical structure, and achieving rapid and deep treatment of difficult-to-degrade organic matter. In addition, the catalyst also has the ability to destroy the cell walls of bacteria and viruses, thereby achieving a disinfection and sterilization effect.

[0019] Photothermal catalytic synergistic technology demonstrates excellent oxidation performance and broad-spectrum and efficient bacterial and viral killing characteristics. This technology not only has the advantages of broad-spectrum high efficiency, green and pollution-free, and high safety, but also can quickly decompose organic matter, realize the purification of wastewater, and achieve the technical goal of rapid degradation of organic matter and efficient sterilization. Finally, the oxidation products are carbon dioxide and water, and the remaining active oxygen is converted into oxygen and released into the air. In the scheme proposed by the present invention, titanium oxide based on a nanoarray structure realizes the process of photocatalysis and oxygen synergistic catalytic oxidation. Specifically, on the surface of the catalyst material, it can catalytically decompose adsorbed oxygen molecules to generate active groups such as oxygen free radicals. Such oxygen free radicals show extremely high activity, with a half-life of microseconds, excellent oxidation ability and efficient sterilization efficiency, thereby achieving the technical standards for efficient degradation and killing of pathogens. This process does not produce secondary pollution, nor does it have residual substances, ensuring the safety of the surrounding environment.

[0020] In an embodiment of the present invention, the performance of the photothermal catalytic synergistic technology can be further improved by optimizing the preparation process of the catalyst. For example, by controlling the particle size and morphology of titanium oxide in the nanoarray structure, the specific surface area of ​​the catalyst can be effectively increased, thereby improving its adsorption capacity for organic matter and bacteria. In addition, by introducing specific doping elements, the electronic structure of the catalyst can be adjusted to enhance its ability to absorb light, thereby improving the photocatalytic efficiency. In practical applications, the catalyst can be made into powder, granular or film-like forms to adapt to different wastewater treatment equipment and process flows. Through these optimization measures, the catalyst of the present invention shows excellent treatment effects when treating different types of wastewater such as industrial wastewater, domestic sewage and hospital wastewater, providing an efficient and environmentally friendly solution for the field of wastewater treatment.

[0021] The advantages of the present invention are: (1) High efficiency degradation performance: This product can quickly and effectively decompose the difficult-to-degrade organic matter in sewage; (2) Broad-spectrum and highly effective disinfection and sterilization capabilities: With its excellent oxidative properties of active oxygen, it can kill bacteria and viruses widely and efficiently; (3) Environmentally friendly characteristics: Its disinfection and sterilization factor - active oxygen, comes from oxygen and oxygen dissolved in water. After completing the disinfection and sterilization task, it will be converted into oxygen and will not cause secondary pollution; (4) Wide applicability: This product can be applied to various types of wastewater treatment, achieving effective degradation and disinfection of various types of sewage; (5) Significant cost-effectiveness: Compared with traditional wastewater treatment methods, the catalyst used in the present invention has lower usage costs and, due to its high efficiency, can shorten the treatment time, thereby reducing overall operating costs. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with specific embodiments. Those of ordinary skill in the art will be able to implement the present invention based on these descriptions. In addition, the embodiments of the present invention involved in the following description are generally only embodiments of a part of the present invention, rather than all embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work should fall within the scope of protection of the present invention.

[0023] Unless otherwise specified, the raw materials used in the examples of the present invention are all commercially available or available to those skilled in the art; unless otherwise specified, the methods used in the examples of the present invention are all methods known to those skilled in the art.

[0024] Unless otherwise specified, the hydrofluoric acid used in the embodiments of the present invention is a commercially available 47% hydrogen fluoride solution.

[0025] Embodiment 1:

[0026] A method for preparing a superoxide catalytic oxidation catalyst, The method comprises: Titanium sulfate, hydrofluoric acid and deionized water are uniformly mixed in a mass ratio of 1:4.4:17 to prepare a base mixed solution. Then, in the one-step synthesis process, ammonia water needs to be added dropwise at a rate of 7%VOL / min of the base mixed solution until the pH of the base mixed solution is adjusted to 8. After the addition is completed, the reaction is stirred for 4 h in an environment with a pressure of 3 MPa and a temperature of 40 °C for one-step synthesis. After the reaction is completed, it is washed with distilled water and dried in an environment with a temperature of 80 °C. Then, it is kept warm in a muffle furnace with a heating rate of 2 °C / min and a heat treatment temperature of 500 °C for 2.5 h, and then naturally cooled to ambient temperature to prepare a superoxide catalytic oxidation catalyst.

[0027] The superoxide catalytic oxidation catalyst prepared in the example was subjected to performance testing, and the specific operation steps and characterization results are as follows.

[0028] COD detection of water samples: pharmaceutical wastewater and industrial wastewater from pharmaceutical factories were collected, and the original COD value of the sampling detection was about 3613.1-3629.6 mg / L. The superoxide catalytic oxidation catalyst prepared in the embodiment was added to the industrial wastewater at a dosage of 120 g / L to degrade the wastewater. After exposure at 55°C for 120 min, the water sample COD was detected using a COD meter and a digester at a temperature of 160°C.

[0029] Escherichia coli detection: Pharmaceutical wastewater was collected and the original concentration of Escherichia coli was about 1×10 5 ~1×10 6 / L, the original fecal coliform concentration is about 1×10 7 ~1×10 8 / L, the superoxide catalytic oxidation catalyst prepared in the example was added into industrial wastewater at a dosage of 120 g / L to degrade the wastewater, and the number of coliform bacteria was detected after exposure at 55°C for 120 min.

[0030] Table 1 Test results of Example 1

[0031]

[0032] It can be clearly seen from the characterization results in Table 1 that after treatment by the present invention, the degree of organic pollution in the discharged sewage can be effectively reduced, and the treated wastewater can be close to the Class B discharge standard (≤500 mg / L) when the sewage undergoes secondary treatment, and due to the superoxide catalytic characteristics of the catalyst of the present invention, the removal effect on Escherichia coli is even more significant. The catalyst of the present invention has good photothermal synergistic catalysis to stimulate the production of a large number of hydroxyl radicals and superoxide ions, which can effectively achieve the degradation of organic pollutants and the elimination of Escherichia coli. In order to further prove the bactericidal ability of the catalyst of the present invention, the same batch of pharmaceutical wastewater was collected, and the original concentration of Escherichia coli was about 1×10 5 ~1×10 6 / L, the original fecal coliform concentration is about 1×10 7 ~1×10 8 / L, and the number of coliform bacteria was tested after exposure to 55 ℃ for 120 min. The test results showed that the concentration of Escherichia coli still reached ≥1×10 4 / L, the concentration of fecal Escherichia coli still reached ≥1×10 7 / L, indicating that although the heating and exposure process can achieve a certain degree of disinfection, and Escherichia coli and fecal coli are not high-temperature resistant bacteria, the actual disinfection efficiency of simple high-temperature exposure is low. In contrast, it is obvious that the catalyst of the present invention can achieve the effect of photothermal synergistic catalytic degradation of pollutants and disinfection of harmful bacteria under medium-temperature heating conditions and exposure.

[0033] Embodiment 2:

[0034] A method for preparing a superoxide catalytic oxidation catalyst, The method comprises: Titanium sulfate, hydrofluoric acid and deionized water are uniformly mixed in a mass ratio of 1:4.45:20 to prepare a base mixed solution. Then, in the one-step synthesis process, ammonia water needs to be added dropwise at a rate of 10%VOL / min of the base mixed solution until the pH of the base mixed solution is adjusted to 8.5. After the addition is completed, the reaction is stirred for 3 h in an environment with a pressure of 4 MPa and a temperature of 45 °C for one-step synthesis. After the reaction is completed, it is washed with distilled water and dried in an environment with a temperature of 80 °C. Then, it is kept warm in a muffle furnace with a heating rate of 2 °C / min and a heat treatment temperature of 525 °C for 2 h, and then naturally cooled to ambient temperature to prepare a superoxide catalytic oxidation catalyst.

[0035] The superoxide catalytic oxidation catalyst prepared in the example was subjected to the same performance test as in Example 1, and the characterization results are as follows.

[0036] Table 2 Test results of Example 2

[0037]

[0038] From the characterization results in Table 2, it can be clearly seen that the catalyst prepared in this example also has good effects of degrading organic pollutants and disinfecting harmful bacteria. Compared with the sample in Example 1, the sample prepared in this example has a slightly improved effect in disinfecting E. coli, while the degradation of organic pollutants is basically the same.

[0039] Embodiment 3:

[0040] A method for preparing a superoxide catalytic oxidation catalyst, The method comprises: Titanium sulfate, hydrofluoric acid and deionized water are uniformly mixed in a mass ratio of 1:4.5:23 to prepare a base mixed solution. Then, in the one-step synthesis process, ammonia water needs to be added dropwise at a rate of 13%VOL / min of the base mixed solution until the pH of the base mixed solution is adjusted to 9. After the addition is completed, the reaction is stirred for 2 hours in an environment with a pressure of 5 MPa and a temperature of 50°C for one-step synthesis. After the reaction is completed, it is washed with distilled water and dried in an environment with a temperature of 80°C. It is then kept warm in a muffle furnace with a heating rate of 2°C / min and a heat treatment temperature of 550°C for 1.5 hours, and then naturally cooled to ambient temperature to prepare a superoxide catalytic oxidation catalyst.

[0041] The superoxide catalytic oxidation catalyst prepared in the example was subjected to the same performance test as in Example 1, and the characterization results are as follows.

[0042] Table 3 Example 3 test results

[0043]

[0044] From the characterization results in Table 3, it can be clearly seen that the catalyst prepared in this example also has good effects of degrading organic pollutants and disinfecting harmful bacteria. Compared with the sample in Example 1, the sample prepared in this example has basically the same effect in disinfecting E. coli, but slightly improved in degradation of organic pollutants.

[0045] Comparative Example 1: A method for preparing a superoxide catalytic oxidation catalyst, wherein the specific preparation method is the same as that of Example 2, and the comparative example only changes the limited range of pH in the present invention. Specifically, the pH of the substrate mixed solution is adjusted to 11 to prepare the superoxide catalytic oxidation catalyst. The catalyst prepared in the comparative example is subjected to the same performance test as that in Example 1, and the characterization results are as follows.

[0046] Table 4 Test results of comparative example 1

[0047]

[0048] From the results in Table 4, it can be seen that in this case, more ammonia water was added in the one-step synthesis process, and the reaction was carried out in a more alkaline environment. In fact, this will have a significant impact on the structure of the product. The impact is mainly reflected in the crystal structure, because under more alkaline conditions, the heat preservation and pressure holding reaction process will cause crystals to precipitate and aggregate faster, resulting in a decrease in the specific surface area of ​​the product and the pore structure is blocked, which is intuitively manifested in a significant increase in the particle size of the obtained product, which leads to a decrease in the contact area between the catalyst and the pollutants (organic pollutants and harmful bacteria), a decrease in the contact rate, and a decrease in the treatment efficiency and treatment effect of the water body. In addition, since the catalyst system of the present invention is a one-step reaction based on the hydrolysis process of titanium salt as the core, the pH value will have a significant impact on the hydrolysis process and the doping process of fluoride ions, because in the hydrolysis process and the doping process, it is necessary to first construct TiO2 / Ti(OH)2·nH2O that is easy to dope, and the present invention also adds hydrogen fluoride as a fluorinating agent. For example, titanium fluoride is directly formed, which itself does not have the ability to excite hydroxyl radicals and superoxide ions to stimulate catalytic oxidation. However, the present invention can effectively achieve ionic fluorine modification through environmental pH value regulation and fluorinating agent coordination, greatly enhancing the photothermal catalytic performance of the catalyst. In particular, in terms of photocatalytic performance, the use of appropriate pH value and fluorinating agent can generate a large number of ≡Ti-F bonds and oxygen defects on the surface of TiO2 / Ti(OH)2·nH2O, thereby promoting the transfer of photogenerated electron-hole pairs, improving the absorption capacity of the catalyst in the visible light region, and enhancing the photocatalytic degradation efficiency. In this case, due to the high pH value of the reaction environment, TiO2 / Ti(OH)2·nH2O will further polymerize and inhibit the forward continuation of the hydrolysis reaction, making fluoride ion doping more difficult and ultimately leading to a significant decrease in catalyst performance.

[0049] Comparative Example 2: A method for preparing a superoxide catalytic oxidation catalyst, wherein the specific preparation method is the same as that of Example 2, and the comparative example only changes the limited range of temperature in the present invention. Specifically, after the dropwise addition is completed, the reaction is stirred for 3 h in an environment with a pressure of 5 MPa and a temperature of 70°C to prepare the superoxide catalytic oxidation catalyst. The catalyst prepared in the comparative example is subjected to the same performance test as in Example 1, and the characterization results are as follows.

[0050] Table 5 Test results of comparative example 2

[0051]

[0052] In this case, a higher reaction temperature was used. Under different temperature conditions, the hydrolysis reaction process will be different. Under relatively low temperature conditions, such as 45°C in Example 2, the hydrolysis reaction rate is relatively slow under relatively low temperature conditions, and the crystallinity of the product formed at this time is usually higher. Generally speaking, the higher the crystallinity, the more difficult it is to dope fluoride ions, which will lead to a worse fluoride ion doping effect, because the order of the crystal structure may hinder the insertion of fluoride ions, and high temperature is conducive to increasing the proportion of amorphous or low crystallinity components in the product TiO2 / Ti(OH)2·nH2O. However, for the technical solution of the present invention, since titanium sulfate and hydrogen fluoride are first mixed, and then preferentially mixed before adding ammonia water to adjust the pH value, it is conducive to first forming a Ti-F complex, thereby realizing deep doping of fluoride ions. Compared with the two-step method of first hydrolyzing to form TiO2 / Ti(OH)2·nH2O and then doping and diffusing fluoride ions with hydrogen fluoride, the present invention improves the preparation efficiency and realizes more effective deep doping of fluoride ions. At the same time, the constructed complex is also conducive to constructing the pore structure of the product, and to a certain extent, the "pore template" is constructed by the "pitting" of hydrogen fluoride. On this basis, the use of a higher reaction temperature will actually lead to a decrease in the crystallinity of the product, and then as shown in Table 5, the structural stability of the product will decrease, and it will be easy to collapse, especially during the post-heat treatment process, resulting in increased pulverization of the product, thereby showing a significant decrease in catalytic degradation ability, which is not conducive to the preparation of high-quality catalysts.

[0053] Comparative Example 3: A method for preparing a superoxide catalytic oxidation catalyst, wherein the specific preparation method is the same as that of Example 2, and the comparative example only changes the limited range of pressure in the present invention. Specifically, after the dropwise addition is completed, the reaction is stirred for 3 h in an environment with a pressure of 8 MPa and a temperature of 45°C to prepare the superoxide catalytic oxidation catalyst. The catalyst prepared in the comparative example is subjected to the same performance test as in Example 1, and the characterization results are as follows.

[0054] Table 6 Test results of comparative example 3

[0055]

[0056] Compared with Example 2, Comparative Example 3 uses a higher ambient pressure for the reaction. Generally speaking, pressure usually does not affect the reaction, but for the present invention, the fluorinating agent and alkaline pH regulator used are actually weak acids and weak bases, and the reaction is in an equilibrium position during the reaction. The change in pressure will cause the reaction equilibrium to change. The increase in pressure may increase the collision frequency between the reactant molecules, thereby accelerating the reaction rate, while affecting the solubility of titanium sulfate and hydrogen fluoride, thereby affecting the reaction. Due to the above-mentioned intensified reaction and the change in reaction equilibrium, more by-products such as TiF4 will be produced, changing the existence form of fluoride ions, and causing the pore structure to be affected, and the crystal structure to change, resulting in a decrease in the comprehensive performance of the product shown in Table 6.

[0057] Comprehensive analysis of the characterization results of Comparative Examples 1, 2 and 3 shows that the catalyst prepared in the comparative examples has poor degradation ability for organic pollutants in pharmaceutical wastewater and weak killing ability for microorganisms. After further research and analysis, the catalyst in the present invention can achieve the purpose of rapid degradation of organic matter and efficient sterilization due to its ability to generate highly oxidizing active oxygen, but it has limitations on the environment during the synthesis process. When the alkalinity during the reaction is too high, the crystal form of titanium oxide formed on the catalyst surface is abnormal, thereby reducing the catalytic activity of the catalyst; when the temperature and pressure during the reaction are too high, the two-dimensional structure of the nanocatalyst cannot be completed due to the excessive catalytic activity of the catalyst itself, thereby reducing the number of catalytic centers and causing a decrease in catalyst activity.

[0058] Comparative Example 4: A method for preparing a superoxide catalytic oxidation catalyst, wherein the specific preparation method is the same as that of Example 2, except that the superoxide catalytic oxidation catalyst is prepared without heat treatment of the catalyst in the present invention. In addition, the catalyst prepared in Example 2 and the catalyst prepared in this example are subjected to cycle life testing, and the specific operation steps and characterization results are as follows.

[0059] The same batch of pharmaceutical wastewater was collected and divided into 12 equal parts. The average initial COD value was 3621.2 mg / L. The catalyst was added to the industrial wastewater at a dosage ratio of 120 g / L to degrade the wastewater. After exposure to 55 °C for 120 min, the COD of the water sample was detected using a COD meter and a digester at a temperature of 160 °C. The catalyst was then taken out and used for the next wastewater degradation. The degradation process operations were the same. The catalyst prepared in Example 2 and the catalyst prepared in this example were simultaneously subjected to multiple wastewater degradations, and the COD of the water samples was detected. The characterization results are as follows.

[0060] Table 7 Comparison of test results of Example 2 and Comparative Example 4

[0061]

[0062] Analyze the characterization results of Table 7 above, the catalyst prepared by the comparative example initially possesses stronger wastewater degradation ability, but the embodiment maintains 99.69% catalytic activity in multiple cycles after heat treatment, and the comparative example only maintains 94.05% catalytic activity, and the initial catalytic performance also has slight differences. This is mainly because the present invention can affect the catalytic activity of the catalyst to a certain extent through the post-heat treatment process, and more importantly, the crystal structure of the product can be effectively stabilized and the conversion of the partly amorphous phase to the crystalline phase can be realized in the process, so as to greatly improve the structural stability of the catalyst. In addition, for this group of comparative example characterization results, the catalyst prepared by Example 2 and the catalyst prepared by this example are tested for 20 cycle lifespans, and the final result shows that Example 2 maintains 97.61% catalytic activity in multiple cycles after heat treatment, and the comparative example 4 only maintains 87.26% catalytic activity, and there is a relatively obvious stability difference.

[0063] Comparative Example 5: A method for preparing a superoxide catalytic oxidation catalyst, wherein the specific preparation method is the same as that of Example 2, except that the ammonia water in the present invention is not used to prepare the superoxide catalytic oxidation catalyst.

[0064] The experimental results show that if the pH value is not adjusted during the reaction process, the precipitate cannot be effectively generated. In the technical solution of the present invention, ammonia water can not only play a role in adjusting the pH value of the reaction system, but more importantly, it can also be used as the main precipitant to promote the formation of precipitates. After further research, it was found that the preparation method using ammonia water as a precipitant can significantly improve the activity and stability of the catalyst. In the process of pH adjustment, the addition of ammonia water helps to form uniform and dense catalyst particles, thereby showing better catalytic performance in the subsequent wastewater treatment process. In addition, the use of ammonia water also reduces the introduction of other impurities and ensures the high purity of the catalyst, which is crucial for the reuse and long-term stability of the catalyst. Therefore, the technical solution of the present invention has significant technical advantages in the preparation of efficient superoxide catalytic oxidation catalysts.

Claims

1. A method for preparing a superoxide catalytic oxidation catalyst, characterized in that: The method comprises: Titanium salt is used as a raw material, a fluorination agent and a dispersing solvent are added to mix as a base mixed solution, and the pH is adjusted to a weak alkaline state, and then the superoxide catalytic oxidation catalyst is synthesized in one step by heat preservation and pressure maintenance reaction.

2. The method for preparing a superoxide catalytic oxidation catalyst according to claim 1, characterized in that: The titanium salt is titanium sulfate; The fluorination agent is hydrofluoric acid; The dispersing solvent is deionized water.

3. The method for preparing a superoxide catalytic oxidation catalyst according to claim 1 or 2, characterized in that: The titanium salt, the fluorination agent and the dispersing solvent are mixed in a mass ratio of 1: (4.4-4.5): (17-23).

4. The method for preparing a superoxide catalytic oxidation catalyst according to claim 1, characterized in that: The process of adjusting the pH to weak alkalinity is to adjust the pH value to 8-9 with ammonia water.

5. The method for preparing a superoxide catalytic oxidation catalyst according to claim 4, characterized in that: The ammonia water is saturated ammonia water; The ammonia water is calculated based on the volume of the base mixed solution, and 7-13% VOL of the base mixed solution is added dropwise every minute.

6. The method for preparing a superoxide catalytic oxidation catalyst according to claim 1, 4 or 5, characterized in that: The heat preservation and pressure preservation reaction process is to react continuously for 2 to 4 hours under the conditions of an ambient pressure of 3 to 5 MPa and an ambient temperature of 40 to 50°C.

7. The method for preparing a superoxide catalytic oxidation catalyst according to claim 1, characterized in that: After the heat preservation and pressure maintenance reaction is completed, the obtained superoxide catalytic oxidation catalyst is dried and then post-heat treated.

8. The method for preparing a superoxide catalytic oxidation catalyst according to claim 7, characterized in that: The post-heat treatment process is: The superoxide catalytic oxidation catalyst is placed in a protective atmosphere, heated to 550-550°C at 2-3°C / min, and then kept at this temperature for 1.5-2.5 hours to effect a crystal phase transformation.

9. A superoxide catalytic oxidation catalyst prepared by the method of any one of claims 1 to 8.

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