Novel Ce and Cu co-doped OMS-2 catalyst as well as construction method and application thereof in photo-thermal synergistic system

Abstract

The invention provides a novel Ce and Cu co-doped OMS-2 catalyst and a construction method and application thereof in a photo-thermal synergistic system, K < + > or Mn < n + > in OMS-2 is successfully replaced by Ce and Cu doping on the basis of a porous cryptolapane type manganese oxide (OMS-2) structure, so that the OMS-2 has richer oxygen vacancies, and VOCs are efficiently degraded in the photo-thermal synergistic system. According to the method, photocatalysis and thermocatalysis technologies are combined on the basis of a photo-thermal synergistic technology, the photocatalysis and thermocatalysis technologies form a synergistic effect, the degradation effect of the method is higher than that of a single photocatalysis and thermocatalysis system, and the method is an emerging and potential VOCs treatment technology.

Description

Technical Field

[0001] The present invention belongs to the technical field of nanomaterial preparation and application, and particularly relates to a novel Ce and Cu co-doped OMS-2 catalyst, a construction method thereof, and an application thereof in a photothermal synergistic system. Background Art

[0002] Volatile organic compounds (VOCs) are major components of atmospheric pollutants and precursors to photochemical smog, tropospheric ozone, and secondary aerosols. These VOCs are widely used as organic solvents in chemical adhesives used in the construction and decoration industries and are therefore continually and accidentally released into the atmosphere. Their neurotoxicity and carcinogenicity can pose a serious threat to human life through long-term exposure, even at trace concentrations. VOCs come in a wide variety of types, including halogenated hydrocarbons, aromatic compounds, aliphatic compounds, aldehydes, ketones, alcohols, ethers, and esters.

[0003] Existing techniques use toluene and ethyl acetate, two common organic solvents, to construct VOC models to study the effects of catalysts. In his master's thesis, Zhang Yangfei noted that the presence of water molecules reduced catalyst activity, speculating that this may be due to competitive adsorption between water and VOCs, which in turn reduces the amount of VOCs adsorbed.

[0004] Thermal catalytic technology is widely used in the degradation of VOCs due to its high degradation efficiency and good stability. However, it generally requires temperatures above 200°C to effectively degrade VOCs, so it consumes a lot of energy. The advantage of photocatalytic technology is that it is safe and simple, and is considered to be a very promising VOCs treatment technology. However, due to its disadvantages such as low degradation efficiency and poor stability, it is difficult to be applied in practice.

[0005] Manganese-based oxides have been widely studied due to their low price, abundant reserves, and excellent photothermal properties. Among them, porous melanin-type manganese oxide (OMS-2) is a unique manganese dioxide with a 2×2 tunnel structure. It is composed of MnO6 octahedrons with shared edges and corners. n+ (Mn 4+ ,Mn 3+ Or Mn 2+ ) are distributed on both sides of the octahedron, K + Located in the tunnel and Mn 3+ Maintain charge balance with oxygen vacancies.

[0006] The effect of porous melanoidin-type manganese oxide (OMS-2) in the field of photothermal synergistic catalysis has not been disclosed. Summary of the Invention To overcome the above problems of the prior art, the present invention provides a novel Ce, Cu co-doped OMS-2 catalyst, its construction method, and its application in a photo-thermal synergistic system. The present invention uses a solvothermal method to successfully dope Ce ions and Cu ions on the surface of OMS-2, forming a uniform and stable nanoflower-like structure, successfully improving the degradation performance of the catalyst for VOCs in the photo-thermal synergistic system, and having good durability, recyclability, and water resistance.

[0008] To achieve the above invention purpose, the technical solution adopted is as follows: In the first aspect of the present invention, there is provided a construction method of a novel Ce, Cu co-doped OMS-2 catalyst, including the following steps: Dissolve potassium permanganate in water, add manganese nitrate solution and stir well, then add copper sulfate and cerium nitrate. After dissolution, place the solution in a polytetrafluoroethylene bottle and seal it in a high-pressure reaction kettle. Subsequently, heat the high-pressure reaction kettle to 80 - 120 °C and maintain it at this temperature for 18 - 30 hours. After the high-pressure reaction kettle cools to room temperature, wash the obtained precipitate with deionized water and dry it to obtain the product.

[0009] In the embodiment of the present invention, the high-pressure reaction kettle is placed in an electric oven and heated to 80 - 120 °C.

[0010] In the embodiment of the present invention, the copper sulfate is CuSO4·5H2O; the cerium nitrate is Ce(NO3)·6H2O.

[0011] Preferably, the mass fraction of the manganese nitrate solution is 30wt% - 70wt%, and the mass ratio of potassium permanganate, manganese nitrate solution, copper sulfate, and cerium nitrate is 3 - 4g: 3 - 4g: 0.05 - 0.5g: 0.05 - 0.5g.

[0012] In the second aspect of the present invention, there is provided a Ce, Cu co-doped OMS-2 catalyst prepared based on the construction method of the novel Ce, Cu co-doped OMS-2 catalyst.

[0013] In the third aspect of the present invention, there is provided the application of the Ce, Cu co-doped OMS-2 catalyst in a photo-thermal synergistic system.

[0014] In the fourth aspect of the present invention, there is provided the application of the Ce, Cu co-doped OMS-2 catalyst in the degradation of VOCs.

[0015] The fifth aspect of the present invention is to provide a VOCs degradation process. In a fixed-bed reactor, a xenon lamp is used as the light source, and the feed gas contains VOCs, oxygen, and nitrogen; the concentration of VOCs is less than 900 ppm. Further, the concentration range of VOCs is 50 - 900 ppm. More specifically, the concentration range of VOCs is 600 - 900 ppm. The wavelength range of the light source is 600 - 800 nm, the light intensity is 400 mW / cm² - 500 mW / cm², and the space velocity is 10000 mL·g -1 ·h -1 ~80000 mL·g -1 ·h -1 ; the reaction temperature is 140 - 200 °C.

[0016] Preferably, the VOCs are esters, benzenes, or aldehydes. In the present invention, the degradation process of ethyl acetate is provided for esters.

[0017] In the embodiments of the present invention, in the VOCs degradation process, when the humidity is controlled within the range of 40% - 70%, high-efficiency degradation effects can be achieved.

[0018] Compared with the prior art, the beneficial effects of the present invention include: 1. The present invention provides a novel Ce, Cu co-doped OMS-2 catalyst, its construction method, and its application in a photo-thermal synergistic system. Based on the structure of porous cryptomelane-type manganese oxide (OMS-2), through Ce, Cu doping, K + or Mn n+ in OMS-2 is successfully replaced, enabling OMS-2 to have more abundant oxygen vacancies, thereby efficiently degrading VOCs under the photo-thermal synergistic system.

[0019] 2. The present invention combines photocatalysis and thermal catalysis technologies based on the photo-thermal synergistic technology, and the two form a synergistic effect. Moreover, its degradation effect is higher than that of single photocatalysis and thermal catalysis systems, making it a very promising VOCs treatment technology.

[0020] 3. The technical solution of the present invention shortens the reaction time, reduces the energy consumption required for the reaction, and realizes the stable degradation of VOCs; reduces the reaction temperature. This product can achieve the efficient degradation of ethyl acetate at about 140 - 200 °C; this product can still maintain a high degradation efficiency after four cycles, indicating that the material has excellent stability.

[0021] 4. The novel Ce and Cu co-doped OMS-2 catalyst provided by the present invention has successfully improved the degradation performance of the catalyst for VOCs in the photo-thermal synergistic system, and has good durability, recyclability and water resistance. Good degradation effect can still be achieved in an environment with a humidity as high as 70%, and effective degradation of VOCs with a concentration of 900 ppm can also be realized. Description of the Drawings

[0022] Figure 1 XRD patterns of the examples and comparative examples.

[0023] Figure 2 Efficiency diagrams of the degradation of ethyl acetate by the examples and comparative examples in the photo-thermal synergistic system.

[0024] Figure 3 Water resistance diagrams of the degradation of ethyl acetate by the examples and comparative examples in the photo-thermal synergistic system.

[0025] Figure 4 Recycling performance diagrams of the degradation of ethyl acetate by the examples and comparative examples in the photo-thermal synergistic system.

[0026] Figure 5 Efficiency diagrams of the degradation of different VOCs by the examples in the photo-thermal synergistic system.

[0027] Figure 6 Efficiency diagrams of the degradation of ethyl acetate by different manganese precursors in the photo-thermal synergistic system.

[0028] Figure 7 Efficiency diagrams of the degradation of ethyl acetate by OMS-2 co-doped with different metals and copper in the photo-thermal synergistic system.

[0029] Figure 8 Scanning electron microscope images of the examples and comparative examples; among them, (a) is the electron microscope image of OMS-2, (b) is the electron microscope image of Cu-OMS-2, (c) is the electron microscope image of Ce-OMS-2, and (d) is the electron microscope image of Cu-Ce-OMS-2.

[0030] Figure 9 Efficiency diagrams of the photo-thermal catalytic degradation of ethyl acetate by catalysts with different cerium doping amounts.

[0031] Figure 10 Effect diagrams of the degradation of different concentrations of ethyl acetate by the catalyst of Example 1.

[0032] Figure 11 Effect diagrams of the influence of different space velocities on the photo-thermal catalytic degradation effect of ethyl acetate by the catalyst of Example 1.

[0033] Beneficial Effects This method prepares a Ce-Cu-OMS-2 catalyst co-doped with Ce and Cu through a simple and easily controllable solvothermal method, which can effectively degrade ethyl acetate in a photo-thermal synergistic system. Ce-Cu-OMS-2 effectively reduces the reaction time and energy consumption required, and has good persistence, water resistance and cyclic practicability, and is expected to be applied in the actual industrial production process. Detailed implementation mode

[0034] To facilitate those skilled in the art to better understand the solution of the present invention and make the above objects, features and advantages of the present invention more understandable, the present invention will be further described in detail below in conjunction with embodiments.

[0035] In the following methods of the present invention, the instruments and reagents used are as follows: Table 1.1 Instruments and equipment

[0036] Table 1.2 Main reagents

[0037] Example 1: Dissolve 3.4637 g of KMnO4 in 20 g of deionized water, add 3.5790 g of 50 wt% Mn(NO3)2 solution, stir well, then add 0.15 g of CuSO4·5H2O and 0.131 g of Ce(NO3)·6H2O. After dissolution, place the solution in a 100 mL polytetrafluoroethylene bottle and seal it in a high-pressure reactor. Then place the high-pressure reactor in an electric oven, heat it to 90 °C, and maintain it at this temperature for 24 hours. After the high-pressure reactor cools to room temperature, wash the obtained precipitate with deionized water 3-4 times, and finally dry it at 100 °C for 12 hours.

[0038] Example 2, The degradation experiment of ethyl acetate was carried out in a fixed-bed reactor of Perfectlight, and all experiments were carried out in a continuous flow system. The light source is a 300 W xenon lamp with a wavelength of 400-800 nm, and the light source uniformly irradiates the entire material surface through a light guide column. The light power intensity under the light guide column was measured with a light intensity meter to be 440 mW / cm². The fixed-bed electric heating function provides the heat for the experiment. In addition, the device is also equipped with a gas path heat tracing function to prevent gas condensation in the gas path so as not to affect the experimental results. The catalyst material was placed in a quartz tube inside the reactor. The feed gas consists of ethyl acetate (EA) gas and 20% O2, and the rest is balanced by N2. The flow rates of all three gases are adjusted through gas flow meters. The reaction temperature is: 160-180 °C; the concentration of ethyl acetate is 700 ppm, and the space velocity is 2,4000 mL·g-1 ·h -1 The humidity was controlled at 40%. The water resistance experiment was also carried out in the above fixed-bed reactor. The difference was that N2 was introduced into the bubbler, and water vapor was introduced into the gas by bubbling to evaluate the water resistance of the material. The bubbling device was equipped with a heating function, and the water content in the total gas flow was controlled by adjusting the gas flow rate and the temperature of the bubbling device.

[0039] Comparative Example 1: Dissolve 3.4637 g of KMnO4 in 20 g of deionized water, add 3.5790 g of 50 wt% Mn(NO3)2 solution, stir well and dissolve. Then place the solution in a 100 mL polytetrafluoroethylene bottle and seal it in a high-pressure reactor. Subsequently, place the high-pressure reactor in an electric oven, heat it to 90 °C, and maintain it at this temperature for 24 hours. After the high-pressure reactor cools to room temperature, wash the obtained precipitate with deionized water 3-4 times, and finally dry it at 100 °C for 12 hours.

[0040] Comparative Example 2: Dissolve 3.4637 g of KMnO4 in 20 g of deionized water, add 3.5790 g of 50 wt% Mn(NO3)2 solution, stir well, and then add 0.15 g of CuSO4·5H2O. After dissolution, place the solution in a 100 mL polytetrafluoroethylene bottle and seal it in a high-pressure reactor. Subsequently, place the high-pressure reactor in an electric oven, heat it to 90 °C, and maintain it at this temperature for 24 hours. After the high-pressure reactor cools to room temperature, wash the obtained precipitate with deionized water 3-4 times, and finally dry it at 100 °C for 12 hours.

[0041] Comparative Example 3: Dissolve 3.4637 g of KMnO4 in 20 g of deionized water, add 3.5790 g of 50 wt% Mn(NO3)2 solution, stir well, and then add 0.131 g of Ce(NO3)·6H2O. After dissolution, place the solution in a 100 mL polytetrafluoroethylene bottle and seal it in a high-pressure reactor. Subsequently, place the high-pressure reactor in an electric oven, heat it to 90 °C, and maintain it at this temperature for 24 hours. After the high-pressure reactor cools to room temperature, wash the obtained precipitate with deionized water 3-4 times, and finally dry it at 100 °C for 12 hours.

[0042] Comparative Example 4 The same preparation method as in Example 1 was used, except that Ce(NO3)·6H2O was replaced by Bi(NO3)·5H2O.

[0043] Comparative Example 5 Dissolve 3.3102 g of MnSO4 in 20 g of deionized water. Add 3.5790 g of 50 wt% Mn(NO3)2 solution, stir well, then add 0.131 g of Ce(NO3)·6H2O. After dissolution, place the solution in a 100 mL polytetrafluoroethylene bottle and seal it in a high-pressure reactor. Subsequently, place the high-pressure reactor in an electric oven, heat it to 90 °C, and maintain this temperature for 24 hours. After the high-pressure reactor cools to room temperature, wash the obtained precipitate with deionized water 3 - 4 times, and finally dry it at 100 °C for 12 hours.

[0044] Test results: 1, Figure 1 Figure 1 is the X-ray diffraction pattern of the products prepared in Example 1 and Comparative Examples 1 - 3. It can be seen from the figure that OMS-2 exhibits a cryptomelane crystal structure (KMn8O 16 , PDF-20-0908). The doping of Cu does not cause an obvious change in the crystal form of OMS-2. The doping of Ce has a greater impact on the crystal form of OMS-2. The signal peak intensity of Ce-Cu-OMS-2 slightly decreases, but it still maintains the crystal characteristics of OMS-2, indicating the successful doping of Cu and Ce.

[0045] 2. Figure 2 shows the degradation efficiency of ethyl acetate by the catalysts prepared in Example 1 and Comparative Examples 1 - 3 in the photo-thermal synergistic system, using the degradation method provided in Example 2.

[0046] The degradation rate is calculated by the following formula:

[0047] As Figure 2 shown, the degradation efficiency of Cu-OMS-2 and Ce-OMS-2 has been significantly improved compared to OMS-2, and the degradation efficiency of about 95% of ethyl acetate can be achieved at 78 minutes. However, the degradation efficiency of Ce-Cu-OMS- is still significantly improved compared to single Cu doping or Ce doping. When the reaction proceeds to 78 minutes, the degradation efficiency of Ce-Cu-OMS-2 for ethyl acetate reaches 99.5%, and the photo-thermal catalytic performance has been significantly improved. The doping of Ce successfully changes the morphology of OMS-2 from the original nanorod structure to a nanoflower structure, so the active sites are significantly increased, and the photo-thermal catalytic performance is correspondingly improved.

[0048] 3, Figure 3The following is the effect diagram of the degradation of ethyl acetate by Example 1 and Comparative Examples 1-3 at different humidities. Using the degradation method provided in Example 2, it can be seen from the figure that although the humidity in the system increases from 40% to 70%, the photothermal catalytic degradation efficiency of the catalyst for ethyl acetate is not affected and remains close to 100%. With the increase of humidity in each comparative example, the degradation effect decreases to varying degrees. This shows that the water resistance of the example is significantly improved compared with that of the comparative example. The experimental results show that Ce-Cu-OMS-2 has the most excellent water resistance among other comparative examples and can always maintain the efficient degradation of 700 ppm ethyl acetate at different humidities, which provides the possibility for its application in the actual industrial production process. The reason for the improvement of the water resistance of Ce-Cu-OMS-2 may be that the morphology of the catalyst changes after Ce doping, generating more active sites. Therefore, even if water vapor occupies some active sites in a high-humidity environment, Ce-Cu-OMS-2 still has enough active sites to efficiently degrade ethyl acetate.

[0049] 4, Figure 4 The following is the cyclic performance effect diagram of Example 1 and Comparative Examples 1-3. Using the degradation method provided in Example 2, it can be clearly seen from the figure that after four cyclic experiments, the degradation efficiency of the catalyst provided by Example 1 for ethyl acetate still maintains the best degradation efficiency, while the degradation efficiency of the other three materials is less than 90% after the fourth cycle. This shows that Ce-Cu-OMS-2 has the best cyclic performance. The reason for the good cyclic performance of Ce-Cu-OMS-2 is that due to the change in morphology, Ce-Cu-OMS-2 has more active sites than other comparative examples. Therefore, after several cycles, the catalyst still has abundant active sites to degrade ethyl acetate.

[0050] 5, Figure 5 The following is the photothermal catalytic experiment of Example 1 for the degradation of different types of VOCs. Using the degradation method provided in Example 2, the experimental results show that Ce-Cu-OMS-2 not only has high photothermal degradation efficiency for ethyl acetate but also has a certain degradation effect on other types of VOCs. It can be seen from the figure that when the reaction proceeds to 78 minutes, the degradation efficiency of Ce-Cu-OMS-2 for toluene reaches 82% and the degradation efficiency for acetaldehyde reaches 91% under the photothermal synergistic system. This shows that Ce-Cu-OMS-2 has wide applicability in the field of VOC degradation.

[0051] 6, Figure 6The following is a comparison of the degradation effects of materials synthesized with different manganese precursors in Example 1 and Comparative Example 5 on ethyl acetate. Using the degradation method provided in Example 2, it can be seen from the figure that the photothermal catalytic performance of the material synthesized with potassium permanganate is significantly better than that of manganese sulfate. The reason for the good performance of the catalyst synthesized with potassium permanganate is that OMS-2 (porous melanin-type manganese oxide) is a unique manganese dioxide with a 2×2 tunnel structure. It is composed of MnO6 octahedrons with shared edges and corners, and Mn n + (Mn 4+ ,Mn 3+ Or Mn 2+ ) are distributed on both sides of the octahedron, K + Located in the tunnel and Mn 3+ Ions and oxygen vacancies maintain charge balance. Therefore, although manganese sulfate contains sufficient manganese sources, it lacks potassium ions. Therefore, it is difficult to form the structure of OMS-2 using manganese sulfate as a precursor catalyst, and the effect is worse than using potassium permanganate as a manganese precursor.

[0052] 7, Figure 7 The following diagrams illustrate the photothermal degradation of ethyl acetate using materials doped with different metals based on Cu-OMS-2 in Example 1 and Comparative Example 4. Using the degradation method provided in Example 2, the Ce-doped catalyst achieves far superior photothermal degradation than the Bi-doped catalyst, demonstrating the unique properties of Ce. This is due to the larger ionic radius of Ce. Upon ion doping, Ce ions replace the Mn ions in OMS-2, disrupting the original tunnel structure of OMS-2. This significantly alters the morphology, creates more active sites, and significantly improves degradation performance.

[0053] 8, Figure 8 This is a scanning electron microscope image of Example 1. It can be seen in the figure that the OMS-2 monomer presents a clear nanorod-like structure, which is the classic morphology of OMS-2, and the morphology does not change much after doping with Cu. The morphology of Ce-OMS-2 after Ce doping changes from the original nanorod-like structure to a layered structure. The morphology of Ce-Cu-OMS-2 has changed significantly compared to OMS-2, Cu-OMS-2 and Ce-OMS-2, showing a nanoflower-like structure. It can be observed from the element distribution diagram that Ce and Cu are evenly distributed on the surface of the material, indicating the successful doping of the two elements.

[0054] 9, Figure 9Figure of the photocatalytic degradation of ethyl acetate by the catalysts in Example 1 with different cerium doping amounts. The degradation method provided in Example 2 was used. The catalyst preparation method is as follows: Dissolve 3.4637 g of KMnO4 in 20 g of deionized water, add 3.5790 g of 50 wt% Mn(NO3)2 solution, stir well, then add 0.15 g of CuSO4·5H2O, and then add 0.524 g, 0.131 g, 0.052 g, and 0.087 g of Ce(NO3)·6H2O respectively. After dissolution, place the solution in a 10 mL polytetrafluoroethylene bottle and seal it in a high-pressure reactor. Subsequently, place the high-pressure reactor in an electric oven, heat it to 90 °C, and maintain it at this temperature for 24 hours. After the high-pressure reactor cools to room temperature, wash the obtained precipitate with deionized water 3-4 times, and finally dry it at 100 °C for 12 hours. The obtained samples are denoted as Ce-Cu-OMS-2-A, Ce-Cu-OMS-2-B, Ce-Cu-OMS-2-C, and Ce-Cu-OMS-2-D respectively.

[0055] The experimental results are shown in the figure. It can be seen from the figure that all four catalysts have a certain degradation effect on ethyl acetate. When the reaction proceeds to 78 minutes, the degradation efficiency of the catalyst with the lowest photocatalytic performance for ethyl acetate reaches more than 80%. Among the four different cerium doping ratios, the best doping ratio is the Ce-Cu-OMS-2-B catalyst, and its degradation efficiency for 700 ppm of ethyl acetate reaches nearly 100% at 78 minutes.

[0056] 10, Figure 10 Figure of the degradation of ethyl acetate with different concentrations by the catalyst in Example 1. The degradation method provided in Example 2 was used, except that the concentration of ethyl acetate was different. The experimental results are shown in the figure. It can be found that the catalyst has a high degradation efficiency for ethyl acetate with a concentration of 600-900 ppm. Even for 900 ppm of ethyl acetate, the degradation efficiency reaches 91% when the reaction proceeds to 78 minutes. This shows that this material can effectively degrade high-concentration ethyl acetate and has excellent photocatalytic performance.

[0057] As known to those skilled in the art, it will still have a good degradation effect at a lower concentration.

[0058] 11, Figure 11 Shows the effect of different space velocities on the photocatalytic degradation of ethyl acetate in Example 1. The degradation method provided in Example 2 was used, except that the space velocity was different. It can be seen from the figure that as the space velocity increases from 24000 mL·g -1 ·h -1 to 72000 mL·g -1 ·h -1, the degradation rate of the catalyst for ethyl acetate slightly decreases. When the reaction proceeds to 84 minutes, even at the highest space velocity of 72000 mL·g -1 ·h -1 , the degradation efficiency of Ce-Cu-OMS-2-B for ethyl acetate can still reach 75%. The experimental results show that even for a high concentration of ethyl acetate of 700 ppm, the catalyst can still achieve efficient degradation of ethyl acetate at a high space velocity. The ethyl acetate degradation experiments at different space velocities successfully prove the high adaptability of the catalyst to the space velocity.

[0059] As known to those skilled in the art, better degradation effects will still be achieved at a lower space velocity.

[0060] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A construction method of a novel Ce, Cu co-doped OMS-2 catalyst, characterized in that, It includes the following steps: Dissolve potassium permanganate in water, add manganese nitrate solution, stir well and mix evenly, then add copper sulfate and cerium nitrate. After dissolution, place the solution in a polytetrafluoroethylene bottle and seal it in a high-pressure reactor. Subsequently, heat the high-pressure reactor to 80 - 120 °C and maintain it at this temperature for 18 - 30 hours. After the high-pressure reactor cools to room temperature, wash the obtained precipitate with deionized water and dry it to obtain the product.

2. The construction method of the novel Ce, Cu co-doped OMS-2 catalyst according to claim 1, characterized in that, Place the high-pressure reactor in an electric oven and heat it to 80 - 120 °C.

3. The construction method of the novel Ce, Cu co-doped OMS-2 catalyst according to claim 1, characterized in that, The copper sulfate is CuSO4·5H2O; the cerium nitrate is Ce(NO3)·6H2O.

4. The construction method of the novel Ce, Cu co-doped OMS-2 catalyst according to claim 1, characterized in that, The mass fraction of the manganese nitrate solution is 30wt% - 70wt%, and the mass ratio of potassium permanganate, manganese nitrate solution, copper sulfate and cerium nitrate is 3 - 4 g : 3 - 4 g : 0.05 - 0.5 g : 0.05 - 0.5 g.

5. The Ce, Cu co-doped OMS-2 catalyst prepared by the construction method of the novel Ce, Cu co-doped OMS-2 catalyst according to any one of claims 1 - 4.

6. The application of the Ce, Cu co-doped OMS-2 catalyst according to claim 5 in a photo-thermal synergistic system.

7. The application of the Ce, Cu co-doped OMS-2 catalyst according to claim 5 in the degradation of VOCs.

8. A VOCs degradation process, characterized in that, In a fixed-bed reactor, a xenon lamp is used as the light source, and the feed gas contains VOCs, oxygen, and nitrogen; the concentration range of VOCs is below 900 ppm, the wavelength range of the light source is 600 - 800 nm, the light intensity is 400 mW / cm² - 500 mW / cm², and the space velocity is 10000 mL·g -1 ·h -1 ~80000 mL·g -1 ·h -1 ; the reaction temperature is 140 - 200 °C.

9. The VOCs degradation process according to claim 8, characterized in that, The VOCs are ester, benzene or aldehyde substances.

10. The VOCs degradation process according to claim 8, characterized in that, The VOCs are ethyl acetate.

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