Preparation method and application of a catalytic wet oxidation catalyst containing rare earth metals

Abstract

The present application discloses a preparation method and application of a catalytic wet oxidation catalyst containing rare earth metals, belonging to the technical fields of catalyst preparation and acrylic acid wastewater treatment. The present application uses a method of self-propagating combustion after mixing a metal precursor with a combustion improver to synthesize a highly stable porous high-entropy oxide serving as a catalyst carrier and a heterogeneous catalyst loaded with noble metal active components in one step. The preparation method of the present invention is simple, has a high yield, good thermal stability and chemical stability, has a rich pore structure, and at the same time has lattice distortion, structural defects and electronic effects caused by the unique "high-entropy effect". The catalyst prepared by the method provided by the present invention is used to treat acrylic acid wastewater, which can significantly improve the service life of the catalyst and the degradation effect of organic matter in the wastewater.

Description

Technical Field

[0001] The present application relates to a preparation method and application of a catalytic wet oxidation catalyst containing rare earth metals, and belongs to the technical fields of catalyst preparation and acrylic acid wastewater treatment. Background Art

[0002] The catalytic wet oxidation (CWAO) technology is an effective method for treating refractory high-concentration wastewater and sludge. At present, the widely used CWAO catalysts are mainly divided into homogeneous catalysts (such as copper-based and iron-based compounds) and heterogeneous catalysts (such as noble metals and oxides). However, the main problem faced by traditional catalysts is the dissolution of active components, resulting in the loss of active sites, thereby reducing the catalytic performance and reuse life. At present, the ways to improve the life and activity disclosed in patents are mainly to add active promoters, especially rare earth metals, or to add a shell layer. For example, CN 105712461B discloses a catalyst with a core-shell structure, with activated carbon as the core and alumina containing noble metals and rare earth metals as the shell, to improve the stability and efficiency of catalytic wet oxidation for treating acrylic acid wastewater.

[0003] High-entropy oxides (HEO) exhibit excellent stability and catalytic activity at high temperatures due to their unique high-entropy effect, lattice distortion, and chemical and physical stability properties. Different from traditional heterogeneous catalysts, HEO is more likely to form a stable solid solution structure, which can effectively improve the service life of the catalyst; at the same time, its diverse structural defects and electronic effects are conducive to promoting the catalytic effect. For example, the literature "Performance of high temperature phase-stable high-entropy oxide (MgCuMnCoFe)Ox in catalytic wet air oxidation of chloroquine phosphate" discloses the synthesis of a high-temperature stable (MgCuMnCoFe)Ox high-entropy metal oxide for catalytic oxidation of chloroquine phosphate degradation, but using the traditional calcination method, the prepared specific surface area is only 0.14 m 2 / g, which is not conducive to the full utilization of the catalyst. Therefore, a new calcination method is needed. Summary of the Invention

[0004] In order to solve the problem of poor stability and catalytic activity of the catalyst at high temperatures in the prior art for the preparation of catalytic wet oxidation catalysts, the present application proposes a technical solution for a catalytic wet oxidation catalyst containing rare earth metals. Utilizing the unique high-entropy effect, lattice distortion, and chemical and physical stability of high-entropy oxides, it exhibits excellent stability and catalytic activity under high-temperature conditions. In addition, rare earth metals that are beneficial for promoting catalytic wet oxidation activity are introduced during the synthesis of high-entropy metal oxides. When used for catalytic wet oxidation treatment of acrylic acid wastewater, the effect is superior to that of traditional catalyst processes.

[0005] The present application adopts the following technical solutions:

[0006] According to the first aspect of the present application, a method for preparing a catalytic wet oxidation catalyst containing rare earth metals is provided, which includes the following steps:

[0007] S1. Heat a solid mixture containing a metal precursor and a combustion aid, and then calcine I the heated solid mixture to obtain a catalyst support;

[0008] The metal precursor is selected from metal salts of at least 5 elements among iron, cobalt, nickel, manganese, molybdenum, magnesium, chromium, copper, lanthanum, neodymium, cerium, and gadolinium, and the metal salts of the at least 5 elements include metal salts of at least one of lanthanum, neodymium, cerium, and gadolinium;

[0009] S2. Immerse the catalyst support in an aqueous solution containing a noble metal salt, and then dry the impregnated catalyst support to obtain a catalyst precursor;

[0010] S3. Calcify II the catalyst precursor to obtain the catalytic wet oxidation catalyst containing rare earth metals.

[0011] Optionally, in step S1, the combustion aid is selected from at least one of citric acid, glycine, urea, and ethylene glycol.

[0012] Optionally, in step S1, the metal salt is selected from at least one of metal nitrates, acetates, chlorides, and perchlorates.

[0013] Optionally, in step S1, based on the weight of the metal element in the metal precursor, the weight ratio of the metal precursor to the combustion aid is 1:4 to 6:1.

[0014] Optionally, in step S1, the heating conditions include: heating at 100°C to 600°C to induce self-propagating combustion of the solid mixture until completion.

[0015] In this application, self-propagating combustion refers to a technology for synthesizing materials by utilizing the self-heating and self-conduction effects of the high chemical reaction heat between reactants. Once the reactants are ignited, they will automatically spread to the unreacted area until the reaction is complete, which is a new method for preparing high-temperature inorganic compound materials.

[0016] Optionally, in step S1, the temperature in the heating condition is 150°C to 300°C.

[0017] Optionally, in step S1, the method for obtaining the solid mixture containing the metal precursor and the combustible is: obtained by mixing and grinding the raw materials containing the metal precursor and the combustible; or, adding the raw materials containing the metal precursor and the combustible to water and stirring to obtain a mixed solution, and drying the mixed solution.

[0018] Optionally, the concentration of the metal precursor in the mixed solution is 5 wt.% to 30 wt.%.

[0019] In this application, the metal precursor and the combustible are mixed by grinding and mixing or by adding the two to water and stirring to obtain a mixed solution. The drying step can set the temperature within the heating temperature range described in step S1, and then the mixture is calcined at 200°C to 600°C to induce self-propagating combustion of the solid mixture.

[0020] Optionally, in step S2, the noble metal salt is selected from metal salts of at least one element among ruthenium, rhodium, palladium, osmium, iridium, and platinum.

[0021] Optionally, the noble metal salt is selected from at least one of nitrates, chlorides, and sulfates of noble metals.

[0022] Optionally, in step S2, the loading concentration of the noble metal salt in the catalyst precursor is 0.1 wt.% to 5 wt.% based on the weight percentage of the heavy metal element.

[0023] Optionally, the conditions for calcination I and calcination II independently include: the calcination temperature is 200°C to 600°C, and the calcination time is 0.5 h to 12 h.

[0024] According to another aspect of this application, a catalytic wet oxidation catalyst containing rare earth metals prepared by the above preparation method is provided. The catalytic wet oxidation catalyst containing rare earth metals includes a carrier and a noble metal supported on the carrier;

[0025] The carrier includes a high-entropy oxide carrier, and the high-entropy oxide carrier contains oxides of at least one element among lanthanum, neodymium, cerium, and gadolinium.

[0026] According to another aspect of the present application, there is also provided an application of a rare earth metal-containing catalytic wet air oxidation catalyst prepared by the above preparation method in the catalytic wet air oxidation degradation of acrylic acid wastewater.

[0027] Optionally, the chemical oxygen demand (COD) of the acrylic acid wastewater is 5000-100000 mg / L.

[0028] Optionally, the conditions for the catalytic wet air oxidation degradation of acrylic acid wastewater include at least one of the following conditions:

[0029] (1) The reaction temperature for the catalytic wet air oxidation degradation of acrylic acid wastewater is 220°C-260°C.

[0030] (2) The volumetric space velocity of the acrylic acid wastewater is 0.5 h -1 ~3 h -1 .

[0031] (3) The reaction pressure for the catalytic wet air oxidation degradation of acrylic acid wastewater is 1.0 MPa-7.0 MPa.

[0032] (4) In the reaction for the catalytic wet air oxidation degradation of acrylic acid wastewater, the oxidant is at least one of air, oxygen, and H2O2.

[0033] Optionally, in the reaction for the catalytic wet air oxidation degradation of acrylic acid wastewater, the actually added amount of oxidant is 5%-50% in excess of the amount of oxidant required for the complete oxidation of acrylic acid in the wastewater.

[0034] The beneficial effects of the present application include:

[0035] The preparation method of the rare earth metal-containing catalytic wet air oxidation catalyst provided by the present application can effectively reduce the acrylic acid content in industrial wastewater and achieve good technical effects by adopting the technical solution of loading noble metals on high-entropy alloy oxides as a heterogeneous catalyst for catalytic wet air oxidation. Description of the Drawings

[0036] Figure 1 It is the XRD pattern of the catalyst samples in Examples 1-8.

[0037] Figure 2 It is the scanning electron microscope photograph and the corresponding element energy spectrum diagram of the catalyst prepared in Example 1. (a) is the scanning electron microscope photograph of the catalyst in Example 1, and (b) is the corresponding element energy spectrum diagram of the catalyst in Example 1, with a scale of 10 μm. Detailed Embodiments

[0038] The present application will be described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0039] Unless otherwise specified, the raw materials in the embodiments of this application are all purchased through commercial channels.

[0040] Unless otherwise specified, the test methods are all conventional methods, and the instrument settings are all the settings recommended by the manufacturer.

[0041] In the embodiments of this application, a Rigaku Ultima IV XRD was used to determine the crystal form of the catalyst; a Shimadzu TOC-VCPH / ce TOC analyzer was used to characterize the total organic carbon content.

[0042] Example 1

[0043] Preparation of the catalytic wet air oxidation catalyst 1.1 Preparation of the catalyst support

[0044] 3.3 g of lanthanum nitrate, 0.58 g of cobalt nitrate, 0.5 g of manganese nitrate, 0.81 g of iron nitrate, 0.58 g of nickel nitrate, 0.48 g of copper nitrate and 0.58 g of citric acid were added to 20 g of water. After stirring and dissolving, it was dried at 120 °C, and the obtained solid was calcined in air at 250 °C for 2 h to obtain the catalyst support.

[0045] 1.2 Preparation of the catalyst

[0046] 50 g of the catalyst support was impregnated in 20 mL of an aqueous solution of ruthenium nitrate with a volume fraction of 0.5%. At room temperature, after impregnation for 24 h, it was dried at 105 °C for 10 h to obtain the catalyst precursor. The catalyst precursor was calcined in an air atmosphere at 350 °C for 4 h to obtain the catalytic wet air oxidation catalyst.

[0047] Catalytic wet air oxidation process The catalytic wet air oxidation catalyst obtained in step 1 was used in a CWAO continuous reaction device to treat acrylic acid model wastewater with a COD of 10,000 mg / L, and the TOC removal rate could reach 85%. Among them, the conditions for the continuous reaction: the reaction temperature was 220 °C, the reaction pressure was 3 MPa, and the volume space velocity of the acrylic acid wastewater was 1 h -1 , the oxidant was oxygen, and the actual dosage was 10% in excess of the oxidation dosage required for the complete oxidation of acrylic acid in the wastewater.

[0048] Example 2

[0049] Preparation of the catalytic wet air oxidation catalyst 1.1 Preparation of the catalyst support

[0050] 2.5 g of cerium nitrate, 0.62 g of chromium nitrate, 0.58 g of manganese nitrate, 0.73 g of magnesium nitrate, 0.45 g of nickel nitrate, 0.48 g of copper nitrate and 0.58 g of ethylene glycol were added to 30 g of water. After stirring and dissolving, it was dried at 105 °C, and the obtained solid was calcined in air at 400 °C for 4 h to obtain the catalyst support.

[0051] 1.2 Preparation of catalyst

[0052] 50 g of catalyst support was impregnated in 20 mL of an aqueous solution of platinum chloride with a volume fraction of 3%. After impregnation at room temperature for 24 h, it was dried at 105 °C for 10 h to obtain a catalyst precursor. The catalyst precursor was calcined in an air atmosphere at 350 °C for 4 h to obtain a catalytic wet air oxidation catalyst.

[0053] In the catalytic wet air oxidation process, the catalytic wet air oxidation catalyst obtained in Step 1 was used in a CWAO continuous reaction device to treat acrylic acid model wastewater with a COD of 20000 mg / L, and the TOC removal rate could reach 85%. Among them, the conditions for the continuous reaction were as follows: the reaction temperature was 250 °C, the reaction pressure was 5 MPa, and the volume space velocity of the acrylic acid wastewater was 0.5 h -1 , and the oxidants were oxygen and air, and the actual dosage was 5% in excess of the oxidation dosage required for the complete oxidation of acrylic acid in the wastewater.

[0054] Example 3

[0055] Preparation of catalytic wet air oxidation catalyst 1.1 Preparation of catalyst support

[0056] 3.5 g of gadolinium nitrate, 0.55 g of copper nitrate, 0.4 g of manganese chloride, 0.68 g of magnesium chloride, 0.53 g of iron chloride, 0.58 g of molybdenum nitrate, and 0.65 g of glycine were added to 20 g of water. After stirring and dissolving, it was dried at 120 °C, and the obtained solid was calcined in air at 300 °C for 5 h to obtain a catalyst support.

[0057] 1.2 Preparation of catalyst

[0058] 50 g of catalyst support was impregnated in 20 mL of an aqueous solution of rhodium chloride with a volume fraction of 2%. After impregnation at room temperature for 24 h, it was dried at 105 °C for 10 h to obtain a catalyst precursor. The catalyst precursor was calcined in an air atmosphere at 350 °C for 4 h to obtain a catalytic wet air oxidation catalyst.

[0059] In the catalytic wet air oxidation process, the catalytic wet air oxidation catalyst obtained in Step 1 was used in a CWAO continuous reaction device to treat acrylic acid model wastewater with a COD of 40000 mg / L, and the TOC removal rate could reach 90%. Among them, the conditions for the continuous reaction were as follows: the reaction temperature was 220 °C, the reaction pressure was 4 MPa, and the volume space velocity of the acrylic acid wastewater was 2 h -1 , and the oxidants were oxygen and air, and the actual dosage was 15% in excess of the oxidation dosage required for the complete oxidation of acrylic acid in the wastewater.

[0060] Example 4

[0061] Preparation of catalytic wet air oxidation catalyst 1.1 Preparation of catalyst support

[0062] 2.8 g of lanthanum chloride, 0.58 g of magnesium perchlorate, 0.63 g of copper nitrate, 0.70 g of molybdenum nitrate, 0.55 g of iron chloride and 0.58 g of urea were added to 30 g of water. After stirring and dissolving, it was dried at 120 °C, and the obtained solid was calcined in air at 350 °C for 3 h to obtain a catalyst support.

[0063] 1.2 Preparation of catalyst

[0064] 50 g of the catalyst support was impregnated in 20 mL of an aqueous solution of palladium nitrate with a volume fraction of 5%. At room temperature, after impregnation for 24 h, it was dried at 105 °C for 10 h to obtain a catalyst precursor. The catalyst precursor was calcined in air at 350 °C for 4 h to obtain a catalytic wet air oxidation catalyst.

[0065] In the catalytic wet air oxidation process, the catalytic wet air oxidation catalyst obtained in Step 1 was used in a CWAO continuous reaction device to treat acrylic acid model wastewater with a COD of 60000 mg / L, and the TOC removal rate could reach 90%. Among them, the conditions for the continuous reaction were as follows: the reaction temperature was 240 °C, the reaction pressure was 4 MPa, and the volume space velocity of the acrylic acid wastewater was 2.5 h -1 , and the oxidants were oxygen and H2O2, and the actual dosage was 30% in excess of the amount of oxidant required for the complete oxidation of acrylic acid in the wastewater.

[0066] Example 5

[0067] Preparation of catalytic wet air oxidation catalyst 1.1 Preparation of catalyst support

[0068] 3.0 g of iridium nitrate, 0.46 g of iron nitrate, 0.33 g of copper chloride, 0.52 g of nickel chloride, 0.35 g of manganese nitrate, 0.25 g of chromium nitrate and 0.55 g of citric acid were added to 30 g of water. After stirring and dissolving, it was dried at 120 °C, and the obtained solid was calcined in air at 200 °C for 4 h to obtain a catalyst support.

[0069] 1.2 Preparation of catalyst

[0070] 50 g of the catalyst support was impregnated in 20 mL of an aqueous solution of platinum nitrate with a volume fraction of 2%. At room temperature, after impregnation for 24 h, it was dried at 105 °C for 10 h to obtain a catalyst precursor. The catalyst precursor was calcined in air at 350 °C for 4 h to obtain a catalytic wet air oxidation catalyst.

[0071] The catalytic wet air oxidation process uses the catalytic wet air oxidation catalyst obtained in Step 1 in a CWAO continuous reaction device to treat acrylic acid model wastewater with a COD of 80,000 mg / L, and the TOC removal rate can reach 80%. Among them, the conditions for the continuous reaction are: the reaction temperature is 220 °C, the reaction pressure is 4 MPa, and the volumetric space velocity of the acrylic acid wastewater is 1.0 h -1 , the oxidant is H2O2, and the actual dosage is 20% in excess of the oxidant dosage required for the complete oxidation of acrylic acid in the wastewater.

[0072] Example 6

[0073] Preparation of the catalytic wet air oxidation catalyst 1.1 Preparation of the catalyst support

[0074] 3.5 g of iridium chloride, 0.55 g of iron nitrate, 0.31 g of copper chloride, 0.52 g of nickel chloride, 0.56 g of manganese nitrate, 0.25 g of chromium nitrate and 0.58 g of ethylene glycol are added to 25 g of water. After stirring and dissolving, it is dried at 105 °C, and the obtained solid is calcined in air at 230 °C for 3 h to obtain the catalyst support.

[0075] 1.2 Preparation of the catalyst

[0076] 50 g of the catalyst support is impregnated in 20 mL of an aqueous solution mixture of 2% palladium nitrate and 1% ruthenium chloride. At room temperature, after impregnation for 24 h, it is dried at 105 °C for 10 h to obtain the catalyst precursor. The catalyst precursor is calcined in an air atmosphere at 350 °C for 4 h to obtain the catalytic wet air oxidation catalyst.

[0077] The catalytic wet air oxidation process uses the catalytic wet air oxidation catalyst obtained in Step 1 in a CWAO continuous reaction device to treat acrylic acid model wastewater with a COD of 10,000 mg / L, and the TOC removal rate can reach 95%. Among them, the conditions for the continuous reaction are: the reaction temperature is 240 °C, the reaction pressure is 6.5 MPa, and the volumetric space velocity of the acrylic acid wastewater is 1.0 h -1 , the oxidant is oxygen, and the actual dosage is 30% in excess of the oxidant dosage required for the complete oxidation of acrylic acid in the wastewater.

[0078] Example 7

[0079] Preparation of the catalytic wet air oxidation catalyst 1.1 Preparation of the catalyst support

[0080] 2.8 g of lanthanum nitrate, 0.55 g of iron chloride, 0.30 g of copper chloride, 0.46 g of nickel chloride, 0.35 g of molybdenum nitrate, 0.27 g of chromium nitrate and 0.55 g of citric acid are added to 30 g of water. After stirring and dissolving, it is dried at 120 °C, and the obtained solid is calcined in air at 380 °C for 6 h to obtain the catalyst support.

[0081] 1.2 Preparation of catalyst

[0082] 50 g of catalyst support was impregnated in 20 mL of an aqueous solution mixture of 1.5% palladium nitrate and 0.5% platinum chloride. At room temperature, after impregnation for 24 h, it was dried at 105 °C for 10 h to obtain a catalyst precursor. The catalyst precursor was calcined in an air atmosphere at 350 °C for 4 h to obtain a catalytic wet air oxidation catalyst.

[0083] The catalytic wet air oxidation process used the catalytic wet air oxidation catalyst obtained in step 1 in a CWAO continuous reaction device to treat acrylic acid model wastewater with a COD of 30000 mg / L, and the TOC removal rate could reach 90%. Among them, the conditions for the continuous reaction were: the reaction temperature was 230 °C, the reaction pressure was 5 MPa, and the volume space velocity of the acrylic acid wastewater was 3.0 h -1 , the oxidant was H2O2, and the actual dosage was 40% in excess of the oxidant amount required for the complete oxidation of acrylic acid in the wastewater.

[0084] Example 8

[0085] Preparation of catalytic wet air oxidation catalyst 1.1 Preparation of catalyst support

[0086] 3.3 g of cerium chloride, 0.50 g of iron nitrate, 0.28 g of copper chloride, 0.33 g of molybdenum chloride, 0.42 g of manganese nitrate, 0.35 g of chromium nitrate and 0.52 g of glycine were added to 25 g of water. After stirring and dissolving, it was dried at 120 °C, and the obtained solid was calcined in air at 350 °C for 4 h to obtain a catalyst support.

[0087] 1.2 Preparation of catalyst

[0088] 50 g of catalyst support was impregnated in 20 mL of an aqueous solution mixture of 3% palladium sulfate and 0.5% ruthenium sulfate. At room temperature, after impregnation for 24 h, it was dried at 105 °C for 10 h to obtain a catalyst precursor. The catalyst precursor was calcined in an air atmosphere at 350 °C for 4 h to obtain a catalytic wet air oxidation catalyst.

[0089] The catalytic wet air oxidation process used the catalytic wet air oxidation catalyst obtained in step 1 in a CWAO continuous reaction device to treat acrylic acid model wastewater with a COD of 60000 mg / L, and the TOC removal rate could reach 80%. Among them, the conditions for the continuous reaction were: the reaction temperature was 250 °C, the reaction pressure was 6 MPa, and the volume space velocity of the acrylic acid wastewater was 1.0 h -1 , the oxidant was H2O2, and the actual dosage was 20% in excess of the oxidant amount required for the complete oxidation of acrylic acid in the wastewater.

[0090] The XRD patterns of the catalyst samples in Examples 1 - 8 are as Figure 1 shown.

[0091] The scanning electron microscope photograph and the corresponding elemental energy spectrum of the catalyst prepared in Example 1 are as follows Figure 2 shown. (a) is the scanning electron microscope photograph of the catalyst in Example 1, and (b) is the corresponding elemental energy spectrum of the catalyst in Example 1, with a scale of 10 μm.

[0092] As mentioned above, these are only several embodiments of this application and do not impose any form of limitation on this application. Although this application is disclosed with preferred embodiments as above, it is not intended to limit this application. Any person skilled in the art, without departing from the technical solution of this application, making some changes or modifications using the disclosed technical content is equivalent to equivalent implementation cases and all fall within the scope of the technical solution.

Claims

1. A method for preparing a catalytic wet oxidation catalyst containing a rare earth metal, characterized in that: The steps include: S1, heating a solid mixture containing a metal precursor and a combustion-supporting material, and then calcining the heated solid mixture to obtain a catalyst carrier; The metal precursor is selected from metal salts of at least five elements selected from iron, cobalt, nickel, manganese, molybdenum, magnesium, chromium, copper, lanthanum, neodymium, cerium, and gadolinium, and the metal salts of at least five elements include at least one metal salt of lanthanum, neodymium, cerium, and gadolinium; S2, impregnating the catalyst support in an aqueous solution containing a noble metal salt, and then drying the impregnated catalyst support to obtain a catalyst precursor; S3, calcining the catalyst precursor II to obtain the rare earth metal-containing catalytic wet oxidation catalyst; The rare earth metal-containing catalytic wet oxidation catalyst comprises a carrier and a noble metal supported on the carrier; The carrier includes a high entropy oxide carrier, and the high entropy oxide carrier includes an oxide of at least one element selected from the group consisting of lanthanum, neodymium, cerium, and gadolinium; In step S2, the loading concentration of the noble metal salt in the catalyst precursor is 0.1 wt.% to 5 wt.% in terms of the weight percentage of the heavy metal element.

2. The preparation method according to claim 1, characterized in that: In step S1, the combustion-supporting material is selected from at least one of citric acid, glycine, urea, and ethylene glycol.

3. The preparation method according to claim 1, characterized in that: In step S1, the weight ratio of the metal precursor to the combustion aid is 1:4-6:1 based on the weight of the metal element in the metal precursor.

4. The preparation method according to claim 1, characterized in that: In step S1, the solid mixture containing the metal precursor and the combustion aid is obtained by mixing and grinding the raw materials containing the metal precursor and the combustion aid; or, the raw materials containing the metal precursor and the combustion aid are added into water and stirred to obtain a mixed liquid, and the mixed liquid is dried to obtain the solid mixture.

5. The preparation method according to claim 1, characterized in that: In step S1, the heating conditions include: heating at 100° C. to 600° C. to induce self-propagating combustion of the solid mixture until completion.

6. The preparation method according to claim 1, characterized in that: In step S2, the noble metal salt is selected from metal salts of at least one element selected from ruthenium, rhodium, palladium, osmium, iridium, and platinum.

7. The preparation method according to claim 1, characterized in that: The conditions of calcination I and calcination II independently include: calcination temperature of 200° C. to 600° C., and calcination time of 0.5 h to 12 h.

8. Use of the rare earth metal-containing catalytic wet oxidation catalyst prepared by the preparation method according to any one of claims 1 to 7 in catalytic wet oxidation degradation of acrylic acid wastewater.

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