Catalyst for purifying CVOCs as well as preparation method and application of catalyst

Abstract

The invention provides a catalyst for purifying CVOCs and a preparation method and application thereof.The catalyst comprises a carrier and active substances loaded on the carrier, the carrier comprises cerium dioxide, and the active substances comprise platinum and vanadium oxide. According to the catalyst provided by the invention, the carrier cerium dioxide, the active component platinum and the vanadium oxide have a synergistic effect, so that the catalyst shows excellent water vapor resistance in a catalytic oxidation reaction in chlorine-containing volatile organic compounds, and the improvement of the V loading capacity remarkably enhances the catalytic oxidation activity of the catalyst to chlorobenzene under a humid condition; the inhibition effect of low V loading capacity is changed into the promotion effect of high V loading capacity, the generation of a toxic byproduct dichlorobenzene can be completely inhibited under a humid condition, and the catalyst has a good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of volatile organic compound purification technology, and relates to a catalyst for purifying CVOCs, its preparation method and application. Background Technology

[0002] Volatile organic compounds (VOCs) are among the major air pollutants, and their effective control is crucial for air pollution prevention and control. There are many types of VOCs, among which chlorinated volatile organic compounds (CVOCs) have a significant impact on the environment and human health due to their high toxicity, high chemical stability, and low biodegradability. Among various CVOCs treatment technologies, catalytic oxidation technology boasts high degradation efficiency, low reaction temperature, and minimal secondary pollution, making it one of the mainstream technologies for end-of-pipe CVOCs control.

[0003] In recent years, studies have shown that V-based catalysts exhibit good activity for the catalytic oxidation of CVOCs. However, actual industrial waste gases typically contain a certain amount of water vapor. Although loading noble metals onto V-based catalysts can mitigate the deactivation caused by H2O molecule adsorption, the catalyst activity inevitably decreases under humid conditions. Furthermore, the content of polychlorinated byproducts (PCBs) is also an important evaluation indicator. In catalytic oxidation reactions, if the reaction pathway is not properly controlled, CVOCs may undergo incomplete oxidation, resulting in PCBs. PCBs often have higher toxicity, and their formation needs to be minimized.

[0004] For example, CN113941345A discloses a catalytic oxidation catalyst for the removal of chlorine-containing VOCs, which is composed of RuO2, SnO2, Ce-Zr-La-PrO2. x The catalyst is composed of hydroxyapatite. Leveraging the low-temperature activity advantage of the noble metal Ru, it exhibits excellent performance in the catalytic oxidation of organic waste gas, while effectively reducing the accumulation of C and Cl species on the catalyst surface and enhancing its resistance to Cl poisoning and carbon deposition poisoning. However, in actual industrial waste gas environments containing water vapor, although the hydroxyapatite in its structure possesses certain adsorption properties, it is difficult to resist the competitive adsorption of large amounts of water vapor, and long-term exposure to water vapor may disrupt the Ce-Zr-La-PrO4 structure. x The structural stability of the composite oxide is affected, which in turn weakens its overall resistance to poisoning.

[0005] CN113908830A discloses a supported noble metal catalyst using γ-Al₂O₃ as a support, with noble metals supported via a room-temperature hydrazine hydrate reduction method. γ-Al₂O₃ exhibits uniform particle size distribution, high purity, high specific surface area, and acidity, possessing not only high-temperature inertness but also the ability to promote the disproportionation reaction of CVOCs, thus aiding their degradation. However, when faced with water-rich industrial waste gas, the acidic sites on the γ-Al₂O₃ support readily adsorb water vapor, altering the surface pH and interfering with the CVOC disproportionation process, leading to a decrease in catalyst activity.

[0006] Therefore, developing efficient, chlorine-resistant, water-resistant, and environmentally friendly catalytic systems is of great significance for the practical industrial application of CVOCs catalytic oxidation technology. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a catalyst for purifying CVOCs, its preparation method, and its applications. The catalyst provided by this invention exhibits excellent resistance to moisture in the catalytic oxidation of chlorinated volatile organic compounds through the synergistic effect of the cerium dioxide support, platinum active component, and vanadium oxide. Furthermore, increasing the vanadium loading significantly enhances the catalyst's activity for the catalytic oxidation of chlorobenzene under humid conditions, transforming the inhibitory effect of low vanadium loading into a promoting effect of high vanadium loading. Under humid conditions, it can completely suppress the formation of the toxic byproduct dichlorobenzene, demonstrating promising application prospects.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a catalyst for purifying CVOCs, the catalyst comprising a support and an active substance supported on the support, the support comprising cerium dioxide and the active substance comprising platinum and vanadium oxide.

[0010] In this invention, Pt is responsible for efficient water vapor dissociation and activation, deep oxidation and by-product inhibition, V dominates C-Cl bond dissociation, and CeO2 provides oxygen transfer and structural stability. Together, the three construct a highly efficient, interference-resistant and low-by-product CVOCs purification system.

[0011] Platinum catalysts exhibit higher catalytic oxidation activity for chlorinated volatile organic compounds in the presence of water vapor because: Pt dissociates and activates H2O to generate a large number of protons, promoting the dissociation of C-Cl bonds in CVOCs molecules and removing Cl species from the catalyst surface, thus promoting the dechlorination of CVOCs to generate HCl, which is further oxidized to CO2 and H2O.

[0012] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The technical objectives and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0013] Preferably, the cerium dioxide has a crystalline structure.

[0014] Preferably, the average size of the catalyst is 10nm to 200nm, such as 10nm, 20nm, 50nm, 80nm, 100nm, 150nm or 200nm, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0015] Preferably, the vanadium oxide includes VO x The range of values ​​is denoted by x, where x > 0, such as x = 2, 2.1, 2.3, 2.5, 2.6, 2.7, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0016] Preferably, the vanadium loading on the support in the vanadium oxide is 1 wt% to 10 wt%, more preferably 5 wt% to 10 wt%, such as 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, or 10 wt%, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0017] In this invention, as the volatile organic compound (V) loading increases, the effect of water vapor on the catalyst changes from inhibitory to promoting. The promoting effect is strongest at a V loading of 5 wt%, and remains constant as the V loading increases further. Furthermore, under humid conditions (5 vol% H₂O), a V loading of 3 wt% almost completely eliminates the byproduct dichlorobenzene, while a V loading of 5 wt% completely eliminates it. This is because: at lower V loadings, the formation of Pt-OV bonds is limited, fewer electrons are transferred from V to Pt, and the H₂O dissociation activation is weak. However, as the V loading increases, a large number of Pt-OV bonds are formed, resulting in a large number of electrons transferred from V to Pt, and a strong H₂O dissociation activation. The proton-rich environment generated by H₂O dissociation activation promotes the breaking of C-Cl bonds and the removal of Cl species from the catalyst surface, leading to the conversion of CVOCs to HCl. When the V loading further increases, due to the limited Pt loading, the Pt-OV structure formed by the catalyst reaches saturation, and the water dissociation activation reaches its limit, thus maintaining a constant promoting effect.

[0018] Preferably, the platinum loading on the support is 0.1wt% to 1wt%, more preferably 0.3wt% to 0.7wt%, for example 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, or 1wt%, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0019] In this invention, by controlling the platinum loading at the above-mentioned preferred value, the synergistic effect between platinum and vanadium oxide is strong, the cost is low, and it is beneficial to improve the catalyst's catalytic oxidation activity for chlorine-containing volatile organic compounds under humid conditions.

[0020] In a second aspect, the present invention provides a method for preparing a catalyst as described in the first aspect, the method comprising:

[0021] A cerium salt, a precipitant, and a solvent are mixed and subjected to a hydrothermal reaction to obtain a precipitate. The precipitate is then subjected to a first calcination to obtain cerium dioxide. The cerium dioxide is then impregnated in a mixed solution of platinum salt and vanadium salt, and the impregnated product is subjected to a second calcination to obtain the catalyst.

[0022] In this invention, a high-performance catalyst can be prepared with only a simple precipitation reaction and impregnation process. The preparation method is simple and suitable for widespread application.

[0023] Preferably, the precipitant comprises urea.

[0024] Preferably, the cerium salt comprises Ce(NO3)3·6H2O.

[0025] Preferably, the solvent includes water.

[0026] Preferably, the mixing takes place during the first stirring.

[0027] Preferably, the mixing time is 60 min to 90 min, such as 60 min, 70 min, 80 min or 90 min, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0028] Preferably, the temperature of the hydrothermal reaction is 115℃ to 125℃, such as 115℃, 117℃, 120℃, 123℃ or 125℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0029] Preferably, the hydrothermal reaction time is 10h to 14h, such as 10h, 11h, 12h, 13h or 14h, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0030] Preferably, the precipitate is washed and dried sequentially before the first calcination.

[0031] Preferably, the platinum salt comprises H2PtCl6.

[0032] Preferably, the vanadium salt comprises NH4VO3.

[0033] Preferably, the impregnation method comprises: adding cerium dioxide to a mixed solution of platinum salt and vanadium salt under a second stirring condition, and then evaporating it until no obvious moisture remains under a third stirring and water bath heating condition.

[0034] In this invention, by impregnating the solution under water bath heating and stirring conditions, the mixed solution is heated more uniformly, which is more conducive to the uniform loading of platinum and vanadium on the support, and the impregnation process is more efficient. However, if the solution is directly placed in an oven for evaporation, it is easy to cause uneven distribution of the active components on the support, thereby leading to a decrease in catalyst activity and stability.

[0035] Preferably, the second stirring speed is 300 rpm to 350 rpm, such as 300 rpm, 310 rpm, 320 rpm, 330 rpm, 340 rpm or 350 rpm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0036] Preferably, the second stirring time is 10 min to 20 min, such as 10 min, 12 min, 15 min, 18 min or 20 min, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0037] Preferably, the rotation speed of the third stirring is 250 rpm to 300 rpm, such as 250 rpm, 260 rpm, 270 rpm, 280 rpm, 290 rpm or 300 rpm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0038] In this invention, adding cerium dioxide to the mixed solution of platinum salt and vanadium salt under vigorous stirring conditions is more conducive to the uniform dispersion of the carrier in the mixed solution.

[0039] Preferably, the water bath heating temperature is 80℃~100℃, such as 80℃, 85℃, 90℃, 95℃ or 100℃, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0040] Preferably, the impregnated product is dried before the second calcination.

[0041] Preferably, the drying temperature is 90℃ to 110℃, such as 90℃, 95℃, 100℃, 105℃ or 110℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0042] Preferably, the first calcination and the second calcination are each carried out independently in an air atmosphere.

[0043] Preferably, the temperatures of the first calcination and the second calcination are each independently between 400°C and 600°C, such as 400°C, 450°C, 500°C, 550°C, or 600°C, but are not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0044] Preferably, the first calcination and the second calcination time are each independently 3h to 5h, such as 3h, 3.5h, 4h, 4.5h or 5h, but are not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0045] Thirdly, the present invention also provides an application of the catalyst as described in the first aspect, the application including the purification of chlorine-containing volatile organic compounds.

[0046] Preferably, the chlorine-containing volatile organic compound contains water vapor.

[0047] Preferably, the water vapor content is 5 vol% to 10 vol%, such as 5 vol%, 6 vol%, 7 vol%, 8 vol%, 9 vol%, or 10 vol%, but it is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0048] Preferably, the concentration of chlorine in the chlorinated volatile organic compound is 300ppm to 700ppm, such as 300ppm, 400ppm, 500ppm, 600ppm or 700ppm, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] (1) The present invention loads the precious metal Pt with different loading amounts of V on the surface of CeO2 support. The preparation method is simple, the amount of precious metal used is low, and the cost is saved.

[0051] (2) The catalyst provided by the present invention has excellent resistance to water vapor in the catalytic oxidation reaction of chlorobenzene. The increase of V loading significantly enhances the activity of the catalyst for catalytic oxidation of chlorobenzene under humid conditions, changing the inhibitory effect of low V loading to the promoting effect of high V loading.

[0052] (3) The catalyst provided by the present invention can completely suppress the generation of toxic byproduct dichlorobenzene under humid conditions and has good application prospects. Attached Figure Description

[0053] Figure 1 XRD patterns of the catalysts provided in Examples 1, 4-6.

[0054] Figure 2 The conversion rate of chlorobenzene degradation under both dry and wet conditions is shown for the catalysts provided in Examples 1, 4-8.

[0055] Figure 3 The mineralization rate diagrams for the catalysts provided in Examples 1, 4-8 under both dry and wet conditions are shown.

[0056] Figure 4 ΔT of chlorobenzene degradation for catalysts provided in Examples 1, 4-8 90,CB picture.

[0057] Figure 5 The graph shows the byproduct content of the catalysts provided in Examples 1, 4-8 under both dry and wet conditions.

[0058] Figure 6 This is a long-term stability graph of the catalyst provided in Example 6.

[0059] in, Figure 2 , Figure 3 and Figure 5 In the diagram, the solid line represents the test results of the catalyst under dry conditions, and the dashed line represents the test results of the catalyst under humid conditions; Figure 4 In the middle, ΔT 90,氯苯 This refers to the temperature required for drying conditions versus the temperature required for humid conditions when the chlorobenzene conversion rate reaches 90%. Detailed Implementation

[0060] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0061] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0062] Example 1

[0063] This embodiment provides a catalyst for purifying CVOCs, comprising a CeO2 support and Pt and VO supported on the CeO2. x The loading of Pt is 0.5 wt%, and the loading of V is 5 wt%. The preparation method is as follows:

[0064] 21.70 g of Ce(NO3)3·6H2O and 9.00 g of urea were mixed in 250 mL of deionized water and stirred at room temperature for 1 h. After hydrothermal treatment at 120 °C for 12 h, the precipitate was washed with deionized water and dried at 100 °C overnight. Finally, the obtained solid was calcined in air at 500 °C for 4 h and labeled as CeO2.

[0065] Dissolve 0.115 g of NH4VO3 and 1.315 mL of H2PtCl6 (3.8 mg / mL) in deionized water, then add 1 g of CeO2 under vigorous stirring at 330 rpm and mix for 15 min. Subsequently, evaporate the mixture in a 90 °C water bath under stirring at 270 rpm until no obvious moisture remains, then dry it in a 100 °C oven overnight, and finally calcine it in air at 500 °C for 4 h to obtain the catalyst.

[0066] Example 2

[0067] This embodiment provides a catalyst for purifying CVOCs, comprising a CeO2 support and Pt and V2O5 supported on the CeO2; wherein the Pt loading is 0.5 wt%, and the V loading in the V2O5 is 5 wt%. The preparation method is as follows:

[0068] 21.70 g of Ce(NO3)3·6H2O and 9.00 g of urea were mixed in 250 mL of deionized water and stirred at room temperature for 1 h. After hydrothermal treatment at 120 °C for 12 h, the precipitate was washed with deionized water and dried at 100 °C overnight. Finally, the obtained solid was calcined in air at 400 °C for 5 h and labeled as CeO2.

[0069] Dissolve 0.115 g of NH4VO3 and 1.315 mL of H2PtCl6 (3.8 mg / mL) in deionized water, then add 1 g of CeO2 under vigorous stirring at 300 rpm and mix for 20 min. The mixture is then evaporated in an 80 °C water bath until no obvious moisture remains, and then dried in a 90 °C oven overnight. Finally, it is calcined in air at 400 °C for 5 h to obtain the catalyst.

[0070] Example 3

[0071] This embodiment provides a catalyst for purifying CVOCs, comprising a CeO2 support and Pt and V2O5 supported on the CeO2; wherein the Pt loading is 0.5 wt%, and the V loading in the V2O5 is 5 wt%. The preparation method is as follows:

[0072] 21.70 g of Ce(NO3)3·6H2O and 9.00 g of urea were mixed in 250 mL of deionized water and stirred at room temperature for 1 h. After hydrothermal treatment at 120 °C for 12 h, the precipitate was washed with deionized water and dried at 100 °C overnight. Finally, the obtained solid was calcined in air at 600 °C for 3 h and labeled as CeO2.

[0073] Dissolve 0.115 g of NH4VO3 and 1.315 mL of H2PtCl6 (3.8 mg / mL) in deionized water, then add 1 g of CeO2 under vigorous stirring at 350 rpm and mix for 10 min. The mixture is then evaporated in a 100 °C water bath until no obvious moisture remains, and then dried in a 110 °C oven overnight. Finally, it is calcined in air at 600 °C for 3 h to obtain the catalyst.

[0074] Example 4

[0075] The difference between this embodiment and Embodiment 1 is that in this embodiment, the loading of V is 1 wt% and the amount of NH4VO3 is 0.023 g.

[0076] The remaining preparation methods and parameters are consistent with those in Example 1.

[0077] Example 5

[0078] The difference between this embodiment and Embodiment 1 is that in this embodiment, the loading of V is 2wt% and the amount of NH4VO3 is 0.046g.

[0079] The remaining preparation methods and parameters are consistent with those in Example 1.

[0080] Example 6

[0081] The difference between this embodiment and Embodiment 1 is that in this embodiment, the loading of V is 3wt% and the amount of NH4VO3 is 0.069g.

[0082] The remaining preparation methods and parameters are consistent with those in Example 1.

[0083] Example 7

[0084] The difference between this embodiment and Embodiment 1 is that in this embodiment, the loading of V is 7wt% and the amount of NH4VO3 is 0.161g.

[0085] The remaining preparation methods and parameters are consistent with those in Example 1.

[0086] Example 8

[0087] The difference between this embodiment and Embodiment 1 is that in this embodiment, the loading of V is 10wt% and the amount of NH4VO3 is 0.23g.

[0088] The remaining preparation methods and parameters are consistent with those in Example 1.

[0089] Example 9

[0090] The difference between this embodiment and Embodiment 1 is that, in this embodiment, the water bath drying process is not performed; instead, the product is dried directly in a 100°C oven overnight.

[0091] The remaining preparation methods and parameters are consistent with those in Example 1.

[0092] Comparative Example 1

[0093] The difference between this comparative example and Example 1 is that in this comparative example, the catalyst only includes the support CeO2 and VO supported on the CeO2. x No H2PtCl6 is added during the preparation process;

[0094] The remaining preparation methods and parameters are consistent with those in Example 1.

[0095] Comparative Example 2

[0096] The difference between this comparative example and Example 1 is that in this comparative example, the catalyst only includes the support CeO2 and Pt supported on the CeO2, and NH4VO3 is not added during the preparation process.

[0097] The remaining preparation methods and parameters are consistent with those in Example 1.

[0098] Structural characterization

[0099] The catalysts prepared in Examples 1, 4-8 were subjected to XRD tests, and the test results are as follows: Figure 1 As shown.

[0100] Performance testing

[0101] 150 mg of catalyst particles (40-60 mesh) prepared in Examples 1-9 and Comparative Examples 1-2 were loaded into a quartz tube microreactor with an inner diameter of 4 mm to form an 8 mm catalyst bed. The reactor was then placed in a heating furnace, and a reaction gas flow was introduced. The degradation effect of the catalyst on chlorobenzene gas was tested at a set temperature under both dry and humid conditions. The test conditions were: CVOCs concentration of 500 ppm and reaction space velocity of 30,000 h⁻¹. -1 Under humid conditions, the water vapor content in CVOCs was 5 vol%. During the test, the reaction was maintained for 40 minutes at each temperature point. The concentrations of chlorobenzene, CO2, and dichlorobenzene in the exhaust gas were detected using gas chromatography equipped with a flame ionization detector (FID) and a thermal conductivity detector (TCD). The test results are as follows: Figures 2-5 And as shown in Table 1.

[0102] In addition, the reaction temperature was kept constant at the temperature required to achieve 90% chlorobenzene conversion (309°C), and the long-term stability of the catalyst prepared in Example 3 was tested. The test results are as follows: Figure 6 As shown.

[0103] Table 1

[0104]

[0105]

[0106] Figure 1 XRD patterns of the catalysts provided in Examples 1, 4-6. Figure 1 It can be seen that the catalysts prepared in Examples 4-6 all exhibit the same diffraction peaks as pure CeO2 (PDF#03-065-5923), and no obvious characteristic peaks of Pt and V phases were detected, indicating that Pt and V are uniformly distributed on the CeO2 surface. The weak reflection peak at 24° of the catalyst prepared in Example 1 with a V loading of 5 wt% belongs to the CeVO4 phase.

[0107] Figures 2-4 The graphs showing the chlorobenzene degradation conversion rate, mineralization rate, and chlorobenzene degradation ΔT of the catalysts provided in Examples 1, 4-8 are respectively. 90,CB picture. Figure 4 In the middle, a negative result indicates that T is under humid conditions. 90 Higher values ​​indicate lower activity; a positive result indicates that T is present under humid conditions. 90 Lower concentration, better activity. Table 1 and... Figures 2-4 This indicates that under humid conditions, as the V loading increases, the effect of water vapor on the catalyst changes from inhibitory to promoting; however, when the V loading reaches a certain value, the promoting effect remains constant.

[0108] Figure 5 The graph shows the byproduct content of the catalysts provided in Examples 1, 4-8. Figure 5 The results show that under dry conditions, the inhibitory effect of the catalyst on byproducts is parabolic, and the inhibitory effect is most obvious when the V loading is 5 wt%. Under humid conditions, the byproduct dichlorobenzene is basically completely eliminated when the V loading is 3 wt%, and dichlorobenzene can be completely eliminated when the V loading is ≥5 wt%.

[0109] Figure 6 This is a long-term stability graph of the catalyst provided in Example 6. Figure 6 This indicates that the catalyst prepared in Example 6 exhibits enhanced and stable activity under humid conditions, and its activity is restored after the removal of moisture. Moisture plays a promoting role in the catalytic oxidation of chlorobenzene.

[0110] Meanwhile, the experimental results of Examples 1 and 9 show that after changing the impregnation method in Example 9, the effect decreased compared to Example 1 due to the poor uniformity of the active component loading on the support. In addition, the catalysts prepared in Comparative Examples 1 and 2 were also less effective than those in Example 1 because they lacked one active component.

[0111] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A catalyst for purifying CVOCs, characterized in that, The catalyst includes a support and an active material supported on the support, wherein the support includes cerium dioxide and the active material includes platinum and vanadium oxide.

2. The catalyst for purifying CVOCs according to claim 1, characterized in that, The cerium dioxide has a crystalline structure; Preferably, the catalyst has an average size of 10 nm to 200 nm.

3. The catalyst for purifying CVOCs according to claim 1 or 2, characterized in that, The vanadium oxide includes VO x x > 0; Preferably, the vanadium loading on the support in the vanadium oxide is 1 wt% to 10 wt%, more preferably 5 wt% to 10 wt%.

4. The catalyst for purifying CVOCs according to any one of claims 1-3, characterized in that, The platinum loading on the support is 0.1 wt% to 1 wt%, more preferably 0.3 wt% to 0.7 wt%.

5. A method for preparing the catalyst according to any one of claims 1-4, characterized in that, The preparation method includes: A cerium salt, a precipitant, and a solvent are mixed and subjected to a hydrothermal reaction to obtain a precipitate. The precipitate is then subjected to a first calcination to obtain cerium dioxide. The cerium dioxide is then impregnated in a mixed solution of platinum salt and vanadium salt, and the impregnated product is subjected to a second calcination to obtain the catalyst.

6. The method for preparing the catalyst according to claim 5, characterized in that, The mixing takes place during the first stirring; Preferably, the mixing time is 60 min to 90 min; Preferably, the temperature of the hydrothermal reaction is 115℃~125℃; Preferably, the hydrothermal reaction time is 10h to 14h; Preferably, the precipitate is washed and dried sequentially before the first calcination.

7. The method for preparing the catalyst according to claim 5 or 6, characterized in that, The platinum salt includes H2PtCl6; Preferably, the impregnation method includes: adding cerium dioxide to a mixed solution of platinum salt and vanadium salt under a second stirring condition, and then evaporating it until no obvious moisture remains under a third stirring and water bath heating condition; Preferably, the second stirring speed is 300 rpm to 350 rpm; Preferably, the second stirring time is 10 min to 20 min; Preferably, the rotation speed of the third stirring is 250 rpm to 300 rpm; Preferably, the water bath heating temperature is 80℃~100℃.

8. The method for preparing the catalyst according to any one of claims 5-7, characterized in that, Before the second calcination, the impregnated product is dried; Preferably, the drying temperature is 90℃~110℃; Preferably, the first calcination and the second calcination are each carried out independently in an air atmosphere; Preferably, the temperatures of the first calcination and the second calcination are each independently 400°C to 600°C; Preferably, the first calcination and the second calcination are each carried out independently for 3 to 5 hours.

9. The application of a catalyst as described in any one of claims 1-4, characterized in that, The application includes the purification of chlorine-containing volatile organic compounds.

10. The application according to claim 9, characterized in that, The chlorine-containing volatile organic compounds contain water vapor; Preferably, the water vapor content is 5 vol% to 10 vol%. Preferably, the concentration of chlorine in the chlorine-containing volatile organic compound is 300 ppm to 700 ppm.

Images