A supported ceria catalyst for removing styrene and a preparation method and application thereof

Abstract

This invention discloses a supported cerium dioxide catalyst for styrene removal, its preparation method, and its application. The catalyst comprises a cerium dioxide support and an active component uniformly loaded on the surface of the cerium dioxide support; the cerium dioxide support is in the form of nanospheres; the active component is selected from metallic silver, or a composite of metallic silver and metallic nickel. The supported cerium dioxide catalyst disclosed in this invention significantly improves its catalytic performance at low temperatures by precisely controlling the morphology and structure of the CeO2 nanosupport and the composition and ratio of the active component. When used for the catalytic oxidation of styrene in rubber industry waste gas, this catalyst can achieve 90% styrene conversion (T0) at 200 °C, with a minimum temperature of 180 °C. 90 ).

Description

Technical Field

[0001] This invention relates to the technical field of environmental catalytic materials, and in particular to a supported cerium dioxide catalyst for the removal of styrene, its preparation method, and its application. Background Technology

[0002] Styrene is one of the world's largest-produced industrial chemicals, widely used in the synthesis of polymers such as synthetic rubber, plastics, and resins. It also has important applications in the pharmaceutical, dye, and pesticide industries. As a key monomer in the rubber industry, styrene can be used to prepare various materials such as aspartame (AS) plastics, styrene-butadiene rubber (SBR), ABS plastics, and polyester resins through self-polymerization or copolymerization. However, styrene is highly irritating and toxic. Exposure to its vapors can cause respiratory irritation and neurasthenia syndrome, and long-term exposure may even increase the risk of cancer. Therefore, efficient treatment of styrene waste gas is of great significance for improving ambient air quality and protecting public health.

[0003] Currently, the main technologies for treating styrene waste gas include adsorption, chemical absorption, condensation, photocatalytic oxidation, and catalytic combustion. Among these, catalytic combustion technology has become one of the mainstream technologies for styrene waste gas treatment due to its high purification efficiency, low secondary pollution, and economic feasibility. This technology, with the help of a catalyst, can completely oxidize styrene waste gas into CO2 and H2O at relatively low temperatures (usually 200–400℃). However, the widespread application of this technology is still limited by the insufficient low-temperature activity of the catalyst, the high actual operating temperature leading to high energy consumption, and the susceptibility of the catalyst to deactivation due to sintering or poisoning.

[0004] In existing research, Sun Qimeng et al. (Sun Qimeng, Xiao Li, Zhao Chaocheng et al. Preparation of titanium-based catalysts and their catalytic oxidation performance of styrene [J]. Journal of Environmental Engineering, 2015, 9(07): 3387–3392.) used TiO2 as a support and loaded MnO xA catalyst was prepared by doping Ce for the catalytic combustion of styrene. The results showed that the catalyst performance was optimal when Mn / Ti = 0.1, Ce / Ti = 0.05, and the calcination temperature was 500 °C, but complete conversion of styrene still required 320 °C. Birgitta et al. (Birgitta Narindri Rara Winayu, Chia-Sheng Shih, Ting-Ke Tseng, HsinChu. Styrene removal by low-temperature catalytic oxidation using Mn2O3 / Al2SiO5[J]. Journal of Physics and Chemistry of Solids, 2024, 111739) used the Mn2O3 / Al2SiO5 catalyst to achieve a 95% styrene conversion (T0.05) at 298 °C with a loading of 38 wt.%. 95 These reports indicate that despite researchers' continuous optimization of catalyst formulations and structures, the ignition temperature of existing catalytic systems remains high, and their catalytic performance is still insufficient to meet the demands of efficient and energy-saving treatment.

[0005] Therefore, developing a catalytic material with excellent low-temperature catalytic activity that can significantly reduce the oxidation temperature of styrene and improve purification efficiency has become a key technical challenge that urgently needs to be overcome in the field of styrene waste gas catalytic treatment. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention discloses a supported cerium dioxide catalyst for styrene removal and its preparation method. This catalyst significantly improves its catalytic performance at low temperatures by precisely controlling the morphology and structure of the CeO2 nanocarrier and the composition and ratio of the active components. When used for the catalytic oxidation of styrene in rubber industry waste gas, this catalyst can achieve 90% styrene conversion at 200 °C, with a minimum temperature of 180 °C. 90 ).

[0007] The specific technical solution is as follows:

[0008] A supported cerium dioxide catalyst for removing styrene includes a cerium dioxide support and an active component uniformly loaded on the surface of the cerium dioxide support.

[0009] The cerium dioxide carrier is in the form of nanospheres;

[0010] The active component is selected from metallic silver, or a combination of metallic silver and metallic nickel.

[0011] Preferred:

[0012] The supported cerium dioxide catalyst has an average particle size of 5–10 nm and a specific surface area of ​​90–100 m². 2 / g, with a pore size of 4~5 nm.

[0013] Preferred:

[0014] The loading of the active component is 0.5 to 2.0 wt%, based on 100% catalyst mass.

[0015] To significantly reduce production costs while ensuring catalytic activity for styrene, a composite of metallic silver and a second metal is preferred.

[0016] Preferably, the second metal is selected from nickel. Further experiments have shown that if other common base metals, such as Co, Cu, Mn, Cr, etc., are used, the supported catalysts prepared by combining them with Ag cannot achieve a treatment efficiency of 90% when catalyzing the oxidation of styrene.

[0017] Further preferred, the mass ratio of metallic silver to metallic nickel is 1:(1~2); more preferably 1:(1~1.5); most preferably 7:8.

[0018] Preferred:

[0019] Based on the catalyst mass of 100%, the loading of the active component is 1.0~2.0 wt%, more preferably 1.5 wt%.

[0020] The present invention also discloses a method for preparing the supported cerium dioxide catalyst for styrene removal, comprising the following steps:

[0021] S1. Dissolve the cerium source precursor in deionized water and stir until completely dissolved to obtain solution A;

[0022] S2. Mix the acidic substance with the alcohol solvent and stir until homogeneous to obtain solution B;

[0023] S3. Under room temperature conditions, solution A and solution B are mixed evenly, and the resulting suspension is subjected to hydrothermal reaction and then calcined at high temperature to obtain nano-spherical cerium dioxide carrier.

[0024] S4. The nanosphere cerium dioxide support is impregnated in an aqueous solution of a soluble salt containing the active component, and then post-treated to obtain the supported cerium dioxide catalyst.

[0025] In step S1:

[0026] Preferably, the cerium source precursor can be selected from one or more of cerium nitrate, cerium ammonium nitrate, cerium chloride, cerium sulfate, and cerium ammonium sulfate; more preferably, cerium nitrate.

[0027] Preferably, the concentration of the cerium source precursor in solution A is 0.1~1 mol / L; more preferably 0.9 mol / L.

[0028] In step S2:

[0029] Preferably, the acidic substance is selected from one or more of formic acid, propionic acid, citric acid, and glacial acetic acid;

[0030] Preferably, the alcohol solvent is selected from one or more of methanol, ethanol, n-propanol, and isopropanol;

[0031] Preferably, the volume ratio of the acidic substance to the alcohol solvent is 1:(20~30); more preferably 1:(25~30); and even more preferably 1:26.

[0032] In step S3:

[0033] Preferably, the volume ratio of solution A to solution B is 1:(9~11).

[0034] Preferably, the hydrothermal reaction is carried out in a high-pressure reactor at a temperature of 170-190 °C for 1-10 h; more preferably, the hydrothermal reaction temperature is 180 °C for 3.5 h.

[0035] Preferably, the high-temperature calcination temperature is 450~550 ℃ and the time is 1~5 h; more preferably, the high-temperature calcination temperature is 500 ℃ and the time is 2 h.

[0036] In step S4:

[0037] Preferably, the impregnation is carried out under sealed and light-proof conditions in a water bath at 50~100 ℃ for 1~12 h; a more preferred impregnation temperature is 60 ℃.

[0038] Preferably, the soluble salt containing the active component is selected from nitrates, sulfates, or chlorides containing the active component; more preferably, it is a sulfate containing the active component.

[0039] Experiments revealed that, equivalent to nitrates containing active components, supported catalysts prepared using sulfates containing active components as raw materials exhibited lower T values. 90 .

[0040] Preferably, the aqueous solution of the soluble salt containing the active component has a concentration of 10-100 mmol / L; more preferably, the concentration is 50-100 mmol / L.

[0041] In this invention, when the active component used is a composite of Ag and Ni, the concentration refers to the concentration of the aqueous solution containing silver soluble salt and the concentration of the aqueous solution containing nickel soluble salt, which are 10~100 mmol / L respectively.

[0042] Preferably, the post-processing includes drying and calcination.

[0043] Specifically, after drying at 50~100 ℃ for 8~24 h, it is then calcined at 400~600 ℃ for 1~6 h.

[0044] The present invention also discloses a catalytic oxidation method for removing styrene, using the aforementioned supported cerium dioxide catalyst.

[0045] Preferred:

[0046] The initial styrene concentration was 300 ppm, and the volume hourly space velocity (VHSV) was 20,000 h⁻¹. -1 The oxygen content is 10 vol%.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] This invention significantly increases the specific surface area of ​​the catalyst and exposes more active sites by precisely controlling the microstructure of the CeO2 support and the loading process of the active components, thereby greatly improving its low-temperature catalytic performance. When used for the catalytic oxidation of styrene in rubber industry waste gas, it achieves high TL while maintaining low cost. 90 It can be significantly reduced to 200 °C; if a single metallic silver load is used, T 90 It can be further reduced to 180 ℃; it effectively overcomes the problem of low catalytic efficiency of existing catalysts at low temperatures, and is suitable for waste gas treatment in the rubber industry, with significant economic and environmental benefits. Attached Figure Description

[0049] Figure 1 Transmission electron microscopy (TEM) images of the supported cerium dioxide catalyst prepared in Example 1 at different magnifications;

[0050] Figure 2 The XRD patterns of the catalysts prepared in Example 1 and Comparative Example 1 are shown below.

[0051] Figure 3 The graph shows the adsorption-desorption curves of the supported cerium dioxide catalysts prepared in Examples 1, 4, and 6, respectively. The upper graph is the adsorption-desorption curve, and the lower graph is the pore size diagram.

[0052] Figure 4 The curves showing the styrene conversion rate as a function of temperature for the catalysts prepared in Examples 1, 4 and Comparative Examples 5-8, respectively, in the catalytic oxidation of styrene.

[0053] Figure 5 The curves show the styrene conversion rate as a function of temperature when the catalysts prepared in Comparative Examples 1-4 were used in the catalytic oxidation of styrene.

[0054] Figure 6 The curves showing the styrene conversion rate as a function of temperature for the catalysts prepared in Examples 2-5 and Comparative Example 1, respectively, used in the catalytic oxidation of styrene.

[0055] Figure 7 The curves show the styrene conversion rate as a function of temperature when the catalysts prepared in Comparative Examples 1 and 9-10 are used in the catalytic oxidation of styrene.

[0056] Figure 8 The curves show the styrene conversion rate as a function of temperature when the catalysts prepared in Comparative Examples 1 and 11-12 are used in the catalytic oxidation of styrene.

[0057] Figure 9 The curves show the styrene conversion rate as a function of temperature for the styrene catalytic oxidation reaction of the supported cerium dioxide catalysts prepared in Examples 1 and 6, respectively. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially. The features and performance of the present invention will be further described in detail below with reference to the embodiments.

[0059] Example 1

[0060] (1) Preparation of CeO2 nanospheres:

[0061] 4 g of cerium nitrate hexahydrate (Ce(NO3)3·6H2O) was weighed and dissolved in 10 mL of deionized water. The solution was sonicated for 30 min to obtain solution A. 4 mL of glacial acetic acid was measured and added to 104 mL of anhydrous ethanol. The mixture was stirred until homogeneous to obtain solution B. Solution A was slowly added to solution B, and the mixture was stirred at room temperature for 30 min. The solution was transferred to a polytetrafluoroethylene-lined hydrothermal reactor and subjected to a hydrothermal reaction at 180 °C for 3.5 h. After the reaction, the product was filtered and washed successively with deionized water until neutral, and then washed twice with anhydrous ethanol. The resulting solid was dried in an oven at 80 °C for 12 h, then transferred to a muffle furnace and heated to 500 °C at a rate of 5 °C / min. The solid was then calcined at this temperature for 2 h to obtain a yellow powdery CeO2 nanosphere carrier.

[0062] (2) Catalyst preparation:

[0063] 2.0 g of the above CeO2 nanospheres were dispersed in 50 mL of deionized water and stirred until homogeneous, denoted as carrier suspension C. 1.378 mL of a 0.094 mol / L AgNO3 aqueous solution and 5 mL of a 0.055 mol / L Ni(NO3)2 aqueous solution were added dropwise to suspension C with continuous stirring during the addition. The mixture was then sealed and protected from light, and magnetically stirred in a 60 ℃ constant temperature water bath for 6 h to complete the impregnation. The impregnated product was dried at 80 ℃ for 12 h, then placed in a muffle furnace and calcined at 450 ℃ at a heating rate of 10 ℃ / min for 4 h, finally yielding an Ag and Ni co-supported (0.7% Ag + 0.8% Ni) / CeO2 nanosphere catalyst. The mass loadings of Ag and Ni were 0.7 wt.% and 0.8 wt.%, respectively.

[0064] Figure 1 The TEM image of the catalyst prepared in this embodiment shows that the catalyst is in the form of regular spheres with an average particle size of 5-10 nm.

[0065] Comparative Example 1

[0066] The CeO2 nanosphere support prepared in step (1) of Example 1 was used directly as the catalyst.

[0067] Figure 2 The XRD patterns of the catalysts prepared in Example 1 and Comparative Example 1 are shown. The comparison shows that the sample after loading the active metal (Example 1) still exhibits typical cubic fluorite structure characteristics, and no obvious crystallization diffraction peaks of metals Ag and Ni were observed, indicating that the loaded metal species are highly dispersed and uniformly loaded.

[0068] Comparative Example 2

[0069] Preparation of CeO2 nanospindle:

[0070] 4.168 g of Ce(NO3)3·6H2O and 1.536 g of urea were weighed and dissolved in 320 mL of deionized water, and sonicated for 30 min. The solution was transferred to a polytetrafluoroethylene-lined hydrothermal reactor and hydrothermally reacted in an oven at 120 ℃ for 8 h. After the reaction, the product was filtered, washed successively with deionized water until neutral, and then washed twice with anhydrous ethanol. The obtained solid was dried in an oven at 80 ℃ for 12 h, and then transferred to a muffle furnace and heated to 500 ℃ at a rate of 5 ℃ / min. Calcination was carried out at this temperature for 2 h to finally obtain yellow powdery CeO2 nanospindle fibers.

[0071] The CeO2 nanospindle prepared in this comparative example was used as a catalyst.

[0072] Comparative Example 3

[0073] Preparation of CeO2 nanorods:

[0074] 4.3422 g of Ce(NO3)3·6H2O was weighed and dissolved in 20 mL of deionized water, and sonicated for 30 min. This solution was then slowly added dropwise to 100 mL of 7 mol / L NaOH aqueous solution, and stirred at room temperature for 30 min to obtain a translucent pinkish-purple suspension. The suspension was transferred to a polytetrafluoroethylene-lined hydrothermal reactor and hydrothermally reacted in an oven at 100 ℃ for 24 h. After the reaction, the product was filtered, washed successively with deionized water until neutral, and then washed twice with anhydrous ethanol. The resulting solid was dried in an oven at 80 ℃ for 12 h, then transferred to a muffle furnace and calcined at 500 ℃ at a heating rate of 5 ℃ / min for 2 h to obtain bright yellow powdery CeO2 nanorods.

[0075] CeO2 nanorods prepared in this comparative example were used as catalysts.

[0076] Comparative Example 4

[0077] Preparation of CeO2 nanocubes:

[0078] The preparation process is basically the same as that of Comparative Example 3, except that:

[0079] Replace the NaOH aqueous solution concentration with 15 mol / L and the hydrothermal reaction temperature with 180 ℃.

[0080] CeO2 nanocubes prepared in this comparative example were used as catalysts.

[0081] Comparative Example 5

[0082] The preparation process is basically the same as in Example 1, except for step (2):

[0083] Replace the Ni(NO3)2 aqueous solution with 5 mL of 0.054 mol / L Co(NO3)2 aqueous solution.

[0084] In this comparative example, Ag and Co co-supported (0.7%Ag+0.8%Co) / CeO2 nanosphere catalysts were finally prepared.

[0085] Comparative Example 6

[0086] The preparation process is basically the same as in Example 1, except for step (2):

[0087] Replace the Ni(NO3)2 aqueous solution with 5 mL of 0.050 mol / L Cu(NO3)2 aqueous solution.

[0088] In this comparative example, Ag and Cu co-supported (0.7%Ag+0.8%Cu) / CeO2 nanosphere catalysts were finally prepared.

[0089] Comparative Example 7

[0090] The preparation process is basically the same as in Example 1, except for step (2):

[0091] Replace the Ni(NO3)2 aqueous solution with 5 mL of 0.058 mol / L Mn(NO3)2 aqueous solution.

[0092] In this comparative example, Ag and Mn co-supported (0.7%Ag+0.8%Mn) / CeO2 nanosphere catalysts were finally prepared.

[0093] Comparative Example 8

[0094] The preparation process is basically the same as in Example 1, except for step (2):

[0095] Replace the Ni(NO3)2 aqueous solution with 5 mL of 0.062 mol / L Cr(NO3)2 aqueous solution.

[0096] In this comparative example, Ag and Cr co-supported (0.7%Ag+0.8%Cr) / CeO2 nanosphere catalysts were finally prepared.

[0097] Comparative Example 9

[0098] The preparation process is basically the same as that of Comparative Example 1, except that the hydrothermal reaction temperature is replaced with 160 °C.

[0099] Comparative Example 10

[0100] The preparation process is basically the same as that of Comparative Example 1, except that the hydrothermal reaction temperature is replaced with 200 °C.

[0101] Comparative Example 11

[0102] The preparation process is basically the same as that of Comparative Example 1, except that the high-temperature calcination temperature is replaced with 400 °C.

[0103] Comparative Example 12

[0104] The preparation process is basically the same as that of Comparative Example 1, except that the high-temperature calcination temperature is replaced with 600 ℃.

[0105] Example 2

[0106] The preparation process is basically the same as in Example 1, except for step (2):

[0107] Replace 1.378 mL of 0.094 mol / L AgNO3 aqueous solution and 5 mL of 0.055 mol / L Ni(NO3)2 aqueous solution with a single 0.984 mL of 0.094 mol / L AgNO3 aqueous solution.

[0108] The catalyst prepared in this embodiment is a single Ag-supported Ag / CeO2 nanosphere catalyst. The mass loading of Ag is 0.5 wt.%.

[0109] Example 3

[0110] The preparation process is basically the same as in Example 2, except for step (2):

[0111] Replace the volume of the single AgNO3 aqueous solution with 1.968 mL.

[0112] The catalyst prepared in this embodiment is a single Ag-supported Ag / CeO2 nanosphere catalyst. The mass loading of Ag is 1.0 wt.%.

[0113] Example 4

[0114] The preparation process is basically the same as in Example 2, except for step (2):

[0115] Replace the volume of the single AgNO3 aqueous solution with 2.953 mL.

[0116] The catalyst prepared in this embodiment is a single Ag-supported Ag / CeO2 nanosphere catalyst. The mass loading of Ag is 1.5 wt.%.

[0117] Example 5

[0118] The preparation process is basically the same as in Example 2, except for step (2):

[0119] Replace the volume of the single AgNO3 aqueous solution with 3.937 mL.

[0120] The catalyst prepared in this embodiment is a single Ag-supported Ag / CeO2 nanosphere catalyst. The mass loading of Ag is 2.0 wt.%.

[0121] Example 6

[0122] The preparation process is basically the same as in Example 1, except for step (2):

[0123] Replace the Ni(NO3)2 aqueous solution with an equal volume and concentration of NiSO4 aqueous solution.

[0124] Figure 3The figures show the adsorption-desorption curves of the supported cerium dioxide catalysts prepared in Examples 1, 4, and 6, respectively. The upper figure shows the adsorption-desorption curves of the supported catalysts, and the lower figure shows the pore size diagram of the supported catalysts. It was observed that the supported cerium dioxide catalyst prepared in Example 1 has a BET specific surface area of ​​96.89 m². 2 / g, BJH pore size is 4.27 nm; the supported cerium dioxide catalyst prepared in Example 4 has a BET specific surface area of ​​92.49 m² / g. 2 / g, BJH pore size is 4.69 nm; the supported cerium dioxide catalyst prepared in Example 6 has a BET specific surface area of ​​91.07 m² / g. 2 / g, BJH pore size is 4.60 nm.

[0125] Application testing

[0126] The catalysts prepared in the above examples and comparative examples were used for the catalytic oxidation of styrene. In a fixed-bed microreactor, the styrene conversion rate of the catalysts at different reaction temperatures was evaluated, conversion-temperature curves were plotted, and their T values ​​were calculated and compared. 90 (The temperature required for styrene conversion to reach 90%). All tests were conducted at atmospheric pressure and a volumetric hourly space velocity (VHSV) of 20,000 h⁻¹. -1 The oxidation of styrene was carried out under the conditions of an initial styrene concentration of 300 ppm (N2 equilibrium gas) and an oxygen content of 10 vol%. The comparison results of the catalytic activities of various catalysts for styrene oxidation are shown in Table 1 below.

[0127] Table 1

[0128]

[0129] Figure 4 The figures show the styrene conversion rate versus temperature for the supported catalysts prepared in Examples 1 and 4, and Comparative Examples 5-8, respectively, used in the catalytic oxidation of styrene. It was observed that Example 4 exhibited the lowest Tconversion. 90 T in Example 1 90 Slightly higher than Example 4, while Comparative Examples 5-8 failed to achieve 90% conversion efficiency throughout the reaction process.

[0130] Figure 5 The figures show the styrene conversion rate as a function of temperature for the catalysts prepared in Comparative Examples 1-4 used in the catalytic oxidation of styrene. It was observed that Comparative Example 1 exhibited the lowest Tconversion. 90 The next comparisons were Comparative Examples 2, 3, and 4.

[0131] Figure 6 The figures show the styrene conversion rate versus temperature for the catalysts prepared in Examples 2-5 and Comparative Example 1 used in the catalytic oxidation of styrene. It was observed that, compared to Comparative Example 1, the temperature at which the catalysts were used in Examples 2-5 was higher.90 All are lower, with Example 4 having the lowest T. 90 .

[0132] Figure 7 The figures show the styrene conversion rate versus temperature for the catalysts prepared in Comparative Examples 1, 9-10, used in the catalytic oxidation of styrene. It was observed that Comparative Example 1 exhibited the lowest Tconversion. 90 Next are comparative examples 9 and 10.

[0133] Figure 8 The curves showing the styrene conversion rate as a function of temperature for the catalysts prepared in Comparative Examples 1 and 11-12 in the catalytic oxidation of styrene were observed. It was found that Comparative Example 1 had the lowest T value. 90 Secondly, there are comparative examples 11 and 12.

[0134] Figure 9 The curves showing the styrene conversion rate as a function of temperature for the supported catalysts prepared in Examples 1 and 6 for the catalytic oxidation of styrene were observed. It was found that in Example 6, the temperature at T... 90 It is lower than that of Example 1.

[0135] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. The specific examples used above to illustrate the present invention are only for the purpose of helping to understand the present invention and are not intended to limit the present invention. Those skilled in the art to which this invention pertains can make several simple deductions, modifications, substitutions, or combinations based on the concept of the present invention. These deductions, modifications, substitutions, or combinations also fall within the scope of the claims of the present invention.

Claims

1. A supported cerium dioxide catalyst for removing styrene, characterized in that, Includes a cerium dioxide support and an active component uniformly loaded on the surface of the cerium dioxide support; The cerium dioxide carrier is in the form of nanospheres; The active component is selected from metallic silver, or a combination of metallic silver and metallic nickel.

2. The supported cerium dioxide catalyst for styrene removal according to claim 1, characterized in that, The catalyst has an average particle size of 5–10 nm and a specific surface area of ​​90–100 m². 2 / g, with a pore size of 4~5 nm.

3. The supported cerium dioxide catalyst for styrene removal according to claim 1, characterized in that: The loading of the active component is 0.5~2.0 wt% based on 100% catalyst mass. When the active component is selected from a combination of metallic silver and metallic nickel, the mass ratio of metallic silver to metallic nickel is 1:(1~2).

4. The supported cerium dioxide catalyst for styrene removal according to claim 1, characterized in that: The loading of the active component is 1.5 wt%, based on a catalyst mass of 100%.

5. A method for preparing a supported cerium dioxide catalyst for styrene removal according to any one of claims 1 to 4, characterized in that, Includes the following steps: S1. Dissolve the cerium source precursor in deionized water and stir until completely dissolved to obtain solution A; S2. Mix the acidic substance with the alcohol solvent and stir until homogeneous to obtain solution B; S3. Under room temperature conditions, solution A and solution B are mixed evenly, and the resulting suspension is subjected to hydrothermal reaction and then calcined at high temperature to obtain nano-spherical cerium dioxide carrier. S4. The nanosphere cerium dioxide support is impregnated in an aqueous solution of a soluble salt containing the active component, and then post-treated to obtain the supported cerium dioxide catalyst.

6. The method for preparing the supported cerium dioxide catalyst for styrene removal according to claim 5, characterized in that: In step S1: The cerium source precursor may be selected from one or more of cerium nitrate, cerium ammonium nitrate, cerium chloride, cerium sulfate, and cerium ammonium sulfate; In solution A, the concentration of the cerium source precursor is 0.1~1 mol / L; In step S2: The acidic substance is selected from one or more of formic acid, propionic acid, citric acid, and glacial acetic acid; The alcohol solvent is selected from one or more of methanol, ethanol, n-propanol, and isopropanol; The volume ratio of acidic substances to alcohol solvents is 1:(20~30); In step S3: The volume ratio of solution A to solution B is 1:(9~11); The hydrothermal reaction was carried out in a high-pressure reactor at a temperature of 170-190 °C for 1-10 h. The high-temperature calcination temperature is 450~550 ℃, and the time is 1~5 h.

7. The method for preparing the supported cerium dioxide catalyst for styrene removal according to claim 5, characterized in that, In step S4: The impregnation is carried out under sealed and light-proof conditions in a water bath at 50~100 ℃ for 1~12 h. The soluble salt containing the active component is selected from nitrates, sulfates, or chlorides containing the active component; The aqueous solution of the soluble salt containing the active component has a concentration of 10~100 mmol / L; The post-processing includes drying and calcination.

8. The method for preparing the supported cerium dioxide catalyst for styrene removal according to any one of claims 5 to 7, characterized in that: In step S3: The hydrothermal reaction temperature was 180 ℃, and the reaction time was 3.5 h. The high-temperature calcination temperature was 500 ℃, and the time was 2 h. In step S4: The soluble salt containing the active component is selected from sulfates containing the active component.

9. A catalytic oxidation method for removing styrene, characterized in that, The supported cerium dioxide catalyst according to any one of claims 1 to 4 is used.

10. The catalytic oxidation method for removing styrene according to claim 9, characterized in that: The initial styrene concentration was 300 ppm, and the volume hourly space velocity (VHSV) was 20,000 h⁻¹. -1 The oxygen content is 10 vol%.

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