Preparation method of heterogeneous catalyst, prepared catalyst and application

Abstract

The invention belongs to the field of catalysts, particularly relates to a preparation method of a heterogeneous catalyst, the heterogeneous catalyst prepared by the preparation method and application, and more particularly relates to a preparation method of an N and P co-doped modified multi-metal carbon-based catalyst, the heterogeneous catalyst prepared by the N and P co-doped modified multi-metal carbon-based catalyst and application of the N and P co-doped modified multi-metal carbon-based catalyst. The catalytic performance and the stability of the heterogeneous catalyst prepared by the preparation method are further improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of catalysts, in particular, relates to a preparation method of a heterogeneous catalyst, the heterogeneous catalyst prepared by the method and the use thereof, more particularly, relates to a preparation method of a N, P co-doped modified multi-metal carbon-based catalyst, the heterogeneous catalyst prepared by the method and the use thereof. BACKGROUND

[0002] In the treatment of aged landfill leachate, due to the complexity of the leachate composition and the high concentration of refractory organic matter, the traditional physical and chemical and biological treatment methods often have poor effects. The heterogeneous ozone catalytic oxidation technology shows significant technical advantages in the treatment of aged landfill leachate, the core of which is to significantly improve the decomposition efficiency and oxidation capacity of ozone through the introduction of catalysts. This technology mainly utilizes the active sites on the surface of heterogeneous catalysts to promote the adsorption and activation of ozone molecules, thereby accelerating the decomposition of ozone to generate highly active hydroxyl radicals (·OH). These hydroxyl radicals have extremely strong oxidizing properties and can attack organic pollutants in the leachate without selectivity, including long-chain organic matter, aromatic compounds and some toxic and harmful substances that are difficult to biodegrade.

[0003] The principle advantages of heterogeneous ozone catalytic oxidation technology are reflected in the following aspects: improving ozone utilization rate: the presence of catalysts can significantly reduce the rate of ozone decomposition into oxygen, while promoting the reaction of ozone with organic pollutants in wastewater. This makes the oxidation capacity of ozone more fully utilized, thereby improving the utilization rate of ozone; accelerating the degradation of pollutants: the catalyst surface can adsorb oil and other organic pollutants in wastewater, greatly increasing the contact probability of these pollutants with ozone molecules. This adsorption helps ozone molecules more effectively attack the chemical bonds of pollutants, accelerating their degradation into harmless small molecular substances such as CO2 and H2O; reducing the requirements of reaction conditions: heterogeneous catalytic oxidation technology can be carried out under relatively mild conditions, such as normal temperature and pressure, which helps to reduce the energy consumption and equipment cost of the treatment process; reducing the generation of by-products: due to the high selectivity of the catalyst, the ozone catalytic oxidation process tends to generate harmless or less harmful by-products, reducing the risk of secondary pollution; improving treatment efficiency.

[0004] However, the existing heterogeneous catalysts prepared have poor catalytic performance and stability to be enhanced. Therefore, there is a need in the art for a heterogeneous catalyst with improved catalytic performance and stability. SUMMARY

[0005] Therefore, in a first aspect, the present application provides a preparation method of a heterogeneous catalyst, comprising the following steps:

[0006] Step S1: pretreatment of the carrier, wherein the carrier is a porous carbon;

[0007] Step S2: non-element modification of the carrier, wherein the carrier after pretreatment in step S1 is dispersed in a solution containing N, P functional groups;

[0008] Step S3: metal modification of the carrier, wherein the carrier after non-element modification in step S2 is dispersed in a solution containing metal salt and low-temperature thin layer drying is performed; and

[0009] Step S4: electrodeposition metal modification of the carrier, wherein the carrier after metal modification in step S3 is dispersed in a solution containing metal salt, an electric field is applied and low-temperature thin layer drying is performed to obtain a heterogeneous catalyst; wherein,

[0010] The parameters of the low-temperature thin layer drying are that the drying temperature is 35-50℃ and the material thickness is 1-3cm.

[0011] The heterogeneous catalyst prepared by using the above preparation method has further improved catalytic performance and stability.

[0012] Further, the porous carbon in step S1 is activated carbon or biochar.

[0013] Further, the specific surface area of the porous carbon in step S1 is >1200m 2 / g and / or the iodine value is >1000mg / g.

[0014] Further, step S1 further comprises mixing and stirring the porous carbon with a dilute nitric acid solution, adjusting the pH value, washing and drying.

[0015] Further, the concentration of the dilute nitric acid solution in step S1 is 0.1-0.3mol / L.

[0016] Further, the solid-liquid ratio of the porous carbon to the dilute nitric acid in step S1 is 1:(1.2-1.5).

[0017] Further, the parameters of the mixing and stirring in step S1 are that the rotation speed is 60-90r / min and / or the time is 2-5h.

[0018] Further, the pH value is adjusted to >6.5.

[0019] Further, the parameters of the drying in step S1 are 75-105℃ and / or the time is 2-6h.

[0020] Further, the N and P containing organic compound solution in step S2 contains one or more of nitro, amino, cyano, pyrrole or pyridine; more preferably, the N containing compound is one or more of nitric acid, urea, nitrate, etc.

[0021] Further, the P containing compound in the N and P containing organic compound solution in step S2 includes one or more of phosphine, phosphonic acid, phosphonic acid ester; more preferably, the P containing compound is one or more of phosphoric acid, potassium dihydrogen phosphate, triphenylphosphine, etc.

[0022] Further, the mass fraction of the N and P containing organic compound solution in step S2 is 2-5%.

[0023] Further, the solid-liquid ratio of the carrier after pretreatment in step S1 to the N and P containing organic compound solution in step S2 is 1:(1.2-1.5).

[0024] Further, step S2 further includes dispersing the carrier after pretreatment in step S1 in the N and P containing organic compound solution for ultrasonic oscillation, cleaning, drying and calcination.

[0025] Further, the parameters of ultrasonic oscillation in step S2 are 1-2h in time and / or 40-100 kHz in frequency.

[0026] Further, the parameters of drying in step S2 are 75-105℃ and / or 2-6h in time.

[0027] Further, the calcination in step S2 is performed in N2 atmosphere.

[0028] Further, the parameters of calcination in step S2 are 500-900℃ in temperature, 1-2h in time, 2-5℃ / min in heating rate, 1-5℃ / min in cooling rate and / or 1.5-2.5L / min in N2 flow rate.

[0029] Further, the metal salt in step S3 is one or more of Mg, Zn or Mn salt; preferably, the metal salt is zinc salt.

[0030] The zinc metal can significantly improve the electrical conductivity by impregnation. This provides a good electrical basis for the subsequent electrodeposition process, accelerates the efficiency and uniformity of electrodeposition. At the same time, it can increase the active sites on the surface of activated carbon and enable the subsequent electrodeposited metal to be more evenly distributed on the surface of activated carbon, thereby improving the activity and stability of the catalyst.

[0031] Further, the metal salt in step S3 is one or more of chloride, sulfate, nitrate, phosphate, citrate; preferably, the metal salt is nitrate or citrate.

[0032] Further, the concentration of the solution of the metal salt in step S3 is 0.05-0.1 mol / L.

[0033] Further, step S3 further comprises dispersing the support after the non-elemental modification in step S2 in a solution containing the metal salt, ultrasonic oscillation, washing and shadow drying, followed by low-temperature thin layer drying and calcination.

[0034] Further, the parameters of the ultrasonic oscillation in step S3 are: time of 6-12 h, and / or frequency of 40-100 kHz.

[0035] Further, the time of the shadow drying in step S3 is 24-36 h.

[0036] Further, the parameters of the calcination in step S3 are: temperature of 300-600℃, time of 1-2 h, heating rate of 2-5℃ / min, and / or cooling rate of 1-5℃ / min.

[0037] During the calcination, the loaded metal, in particular zinc, can act as a pore-forming agent, forming a porous structure between the active metal oxides. This not only provides a basis for the uniform distribution of the oxidatively active species, but also increases the specific surface area of the carbon-based catalyst.

[0038] Further, the metal salt in step S4 is one or more of Mn, Fe, Cu, Li, Co, Ni, or Rh salt. Preferably, the metal salt in step S4 is Mn-Cu; Mn-Cu-Co.

[0039] Further, the final catalyst support loaded metal is Zn-Mn-Cu; Zn-Mn-Cu-Co. More preferably, the Zn-Mn-Cu multi-metal catalyst, the ratio of the three metals is 1:(1.5-2.5):(1-2); the Zn-Mn-Cu-Co multi-metal catalyst, the ratio of the four metals is 1:(1.5-2.5):(1-2):(1-2).

[0040] The electrodeposition of the metal in step S4 can form a synergistic effect with the metal modification in step S3, further improving the catalytic performance of the catalyst.

[0041] Further, the concentration of the solution of the metal salt in step S4 is 0.01-0.1 mol / L.

[0042] Further, the step S4 further comprises dispersing the carrier after metal modification in a solution containing metal salt, applying an electric field, rinsing and shadow drying, then low temperature thin layer drying and calcination to obtain the heterogeneous catalyst.

[0043] Further, the parameters of the electric field applied in the step S4 are: current density of 1-2.5 A / dm 2 , cell voltage of 4-6 V, and / or solution temperature of room temperature.

[0044] Further, the parameters of the calcination in the step S4 are: temperature of 700-950℃, time of 3-5 h, heating rate of 2-5℃ / min, and / or cooling rate of 1-5℃ / min.

[0045] Further, the metal salt solution in the steps S3 and S4 can be the same or different, preferably different.

[0046] In a second aspect, the present application provides a heterogeneous catalyst prepared according to the above method.

[0047] In a third aspect, the present application provides the use of the heterogeneous catalyst according to the present application in catalyzing ozone treatment of wastewater and / or waste liquid.

[0048] Further, the wastewater and / or waste liquid is aged landfill leachate, or oilfield produced water. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 Schematic diagram of the gain effect of low temperature thin layer drying and electrodeposition modification involved in Example 1 of the present application;

[0050] Figure 2 Electrodeposition modification device used in step 4) of Example 1 of the present application;

[0051] Figure 3 XRD and XPS analysis diagrams of the multi-metal catalyst (Zn-Mn-Cu-Co-CN) obtained in Example 1 of the present application;

[0052] Figure 4 SEM-EDS diagram of the multi-metal catalyst (Zn-Mn-Cu-Co-CN) obtained in Example 1 of the present application. DETAILED DESCRIPTION

[0053] The present application will be specifically described below in conjunction with specific embodiments and examples, and the advantages and various effects of the present application will be more clearly presented. It should be understood by those skilled in the art that these specific embodiments and examples are used to illustrate the present application, rather than limit the present application.

[0054] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0055] Unless otherwise specified, all embodiments and optional embodiments of this application may be combined to form new technical solutions.

[0056] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0057] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0058] Unless otherwise specified, the terms used in this application have the common meanings as commonly understood by those skilled in the art.

[0059] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprise” and / or “comprising,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0060] When the catalyst is in a stacked state and dried at high temperature, the modified metal solution remaining inside the activated carbon channels will migrate towards the channel openings due to capillary effect, causing the metal precursor solution to accumulate on the support surface. This accumulation leads to localized enrichment of the metal precursor on the catalyst surface, resulting in uneven metal distribution. This uneven distribution affects the catalyst's activity and stability. Furthermore, the accumulated metal precursor may form large particles during subsequent calcination, clogging the activated carbon channels. This not only reduces the catalyst's specific surface area but also decreases the number of active sites, thereby reducing catalyst performance. Therefore, this invention employs a low-temperature thin-layer drying process for catalyst preparation.

[0061] Example 1

[0062] The heterogeneous catalyst of the present invention was prepared according to the method shown below, and its gain effect is as follows: Figure 1 As shown:

[0063] 1) Pretreatment of the carrier

[0064] Take 50g of porous carbon and add it to 60ml of 0.3mol / L dilute nitric acid solution. Mix and stir for 3h at a stirring speed of 60r / min. Take out the porous carbon material and rinse it with deionized water until the pH of the rinsing solution is >6.5. Then dry it in an oven at 85℃ for 4h to obtain porous carbon support (CN support).

[0065] 2) Modification of carrier with non-metallic elements

[0066] Take 50g of the CN support obtained in the previous step and place it in 75ml of a 2% (w / w) mixed solution of urea and potassium phosphate. Sonicate for 1.5h to fill the pores in the support with organic solution. The ultrasonic oscillation frequency is 80 kHz. After separating the support, rinse it with deionized water more than three times and then dry it in an oven at 75℃ for 4h. Place the dried support in a tube furnace and calcine it under a N2 atmosphere at a calcine temperature of 550℃ for 2h. The heating rate is 5℃ / min, the cooling rate is 5℃ / min, and the N2 flow rate is 2L / min. After cooling, the N and P co-doped CN support is obtained.

[0067] 3) Impregnation with metal modification

[0068] 50g of the N and P co-doped CN carrier was placed in 75ml of 0.1mol / L zinc nitrate solution and ultrasonically impregnated for 12h. After impregnation, the CN was separated from the modified salt solution, rinsed with deionized water more than three times, and air-dried for 36h. The material was then cut into 3cm thick layers and placed in a constant temperature oven at 35-50℃ for low-temperature thin-layer drying for 15h. The dried material was then placed in a muffle furnace for calcination at 600℃ for 2h, with a heating rate of 5℃ / min and a cooling rate of 5℃ / min. The CN modified with impregnated metal was obtained after cooling and named Zn-CN.

[0069] 4) Electrodeposition metal modification

[0070] The Zn-CN prepared in the above steps is placed in an electrodeposition metal modification device, such as... Figure 2 As shown, the material was immersed in a 0.1 mol / L mixed solution of manganese nitrate and copper nitrate, and an electric field was applied with a current density of 2.5 A / dm². 2 The voltage on the tank is 5V. After 4 hours, the material is taken out, rinsed with deionized water more than three times, and air-dried for 36 hours. The material is then cut into layers with a thickness of 3cm and placed in a constant temperature oven at 35-50℃ for 18 hours. Then it is calcined in a muffle furnace at a temperature of 900℃ for 4 hours, with a heating rate of 5℃ / min and a cooling rate of 5℃ / min. The electrodeposited metal-modified CN is named Zn-Mn-Cu-CN.

[0071] Example 2

[0072] Repeat Example 1, except that: the metal salt in step 4) is a mixed solution of manganese nitrate, ferric nitrate and cobalt nitrate, with a total concentration of 0.1 mol / L.

[0073] Example 3

[0074] Repeat Example 1, except that the roasting temperature in step 4) is 800°C and the roasting time is 5 hours.

[0075] Example 4

[0076] Example 1 was repeated, with the exception that the metal modification in step 3) was changed from zinc to magnesium.

[0077] Comparative Example 1

[0078] Example 1 was repeated, with the exception that step 2) was removed, and the carrier was selected to be a carbon carrier without N, P co-doped modification.

[0079] Comparative Example 2

[0080] Example 1 was repeated, with the exception that the low-temperature thin-layer drying process in step 3) and step 4) was not used, and the material was directly stacked and dried in a constant-temperature oven at a temperature of 105°C for 15h.

[0081] Comparative Example 3

[0082] Example 1 was repeated, with the exception that the low-temperature thin-layer drying process in step 3) and step 4) was not used, and the material was directly stacked and dried in a constant-temperature oven at a temperature of 35-50°C for 18h.

[0083] Comparative Example 4

[0084] Example 1 was repeated, with the exception that step 4) was removed, and the prepared catalyst was not subjected to metal modification by electrodeposition.

[0085] Comparative Example 5

[0086] Example 1 was repeated, with the exception that step 3) was removed, and the prepared catalyst was not subjected to metal modification by impregnation.

[0087] Catalytic performance of the heterogeneous catalyst prepared by the present application

[0088] The catalysts prepared by the present application, examples 1-3 and comparative examples 1-3, were used for the treatment of experimental wastewater from the nanofiltration effluent of an aged landfill leachate of a landfill in Zhangzhou, Fujian. The specific treatment results are shown in Table 1.

[0089] Table 1

[0090]

[0091] Stability of the heterogeneous catalyst prepared by the present application

[0092] The catalysts prepared by the present application, examples 1-3 and comparative examples 1-3, were used for stability experiments, by simulating the actual production conditions: reaction → end → restart (cycle ≥ 20 times), and then measuring the final activity fluctuation. The specific results are shown in Table 2.

[0093] Table 2

[0094]

[0095]

[0096] XRD and XPS analysis of the heterogeneous catalyst prepared in the present invention

[0097] XRD and XPS analysis of the heterogeneous catalyst prepared in Example 1

[0098] The catalyst material prepared in Example 1 was characterized by Shimadzu XRD-7000S / L X-ray diffractometer and Thermo Fisher Scientific K-Alpha X-ray photoelectron spectrometer, and the specific results are shown in Figure 3 The active components containing Zn, Cu, Co and Mn have been successfully loaded on the surface of AC support, and these metals exist in the form of CuO, Cu2O, Co3O4, MnO2, Mn2O3 and ZnO2, for example, diffraction peaks appear at 2θ = 38.73°, 48.50°, 61.45°, 66.08°, 68.95°, which correspond to the typical

[111] , [-202], [-113], [-311],

[113] crystal faces of CuO (PDF # 89-5897); the characteristic peak at 2θ = 36.40° represents the

[111] crystal face of Cu2O (PDF # 99-0041); the characteristic peaks near 2θ = 28.7°, 37.4° belong to MnO2 (PDF 44-0141).

[0099] From the XPS scanning spectrum, we can observe the diffraction peaks of active components Cu2p, Co2p and Mn2p. In Figure 3 (b), Cu2p3 / 2 characteristic peaks at 933.5 eV and 934.5 eV can be observed, and the wide satellite peak at 941.2 eV proves the existence of Cu(II). In Figure 3 (c), Mn2p3 / 2 characteristic peaks are located at 641.1 eV, 642.2 eV and 643.4 eV, and Mn2p1 / 2 characteristic peaks are located at 653.4 eV and 653.8 eV, and analysis shows that 641.1 eV, 643.4 eV and 653.8 eV are the peak value distribution of Mn(II), and 642.2 eV, 653.4 eV are the peak value distribution of Mn(III). Figure 3In (d), characteristic peaks of Co2p3 / 2 were observed at 779.8 eV and 781.1 eV, while characteristic peaks of Co2p1 / 2 were observed at 794.7 eV and 796.1 eV. The peak distribution at 781.1 eV and 796.1 eV corresponds to Co(II), while the peaks at 779.8 eV and 794.7 eV confirm Co(III). No zinc metal was detected in the XPS surface analysis. During the electrodeposition process, metals such as Co, Mn, and Cu may have formed a thick coating layer on the surface, covering the zinc metal. This also indirectly indicates that the electrodeposited modified metal layer is uniform.

[0100] SEM-EDS analysis of the heterogeneous catalyst prepared in this invention

[0101] Analysis of the microstructure of the catalyst prepared in Example 1 using scanning electron microscopy (SEM) revealed that the catalyst possesses abundant pores, with most pore walls interconnected to form a three-dimensional porous structure. The pore size ranges from 5 to 10 μm. This nanoscale pore structure is a crucial prerequisite for the catalyst to exhibit ultra-high specific surface area and abundant active sites. On the surface and within the pores of the AC support, interwoven clusters of protrusions and fibrous columnar structures are clearly visible. At higher magnification, Image 4 shows a large number of irregular fine particles on the catalyst surface. Preliminary analysis suggests that these particles may be supported Cu, Co, and Mn.

[0102] Energy dispersive spectroscopy (EDS) further confirmed the types and contents of active components supported on the catalyst surface. For example... Figure 4 As shown, zinc (Zn), copper (Cu), cobalt (Co), and manganese (Mn) were detected on the catalyst surface, and the distribution of each metal element was displayed. This indicates that the target active component has been successfully loaded onto the AC support surface. Specifically, the mass percentages of zinc oxide (ZnO), copper oxide (CuO, Cu2O), Co oxide (Co3O4), and manganese oxide (MnO2, Mn2O3) are 2.93%, 3.04%, 2.77%, and 2.83%, respectively, with a ratio close to 1:1:1:1. The synergistic effect between the metals is beneficial to the improvement of catalytic efficiency.

[0103] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A method for preparing a heterogeneous catalyst, comprising the following steps: Step S1: Pretreatment of the support, wherein the support is porous carbon; Step S2: Non-elemental modification of the support, wherein the pretreated support in step S1 is dispersed in an organic solution containing N and P functional groups; Step S3: Metal modification of the support, wherein the support after non-elemental modification in step S2 is dispersed in a solution containing a metal salt and then subjected to low-temperature thin-layer drying; and Step S4: Electrodeposition metal modification of the support, wherein the metal-modified support from step S3 is dispersed in a solution containing a metal salt, an electric field is applied, and the mixture is dried at low temperature to obtain a heterogeneous catalyst; wherein, The parameters for the low-temperature thin-layer drying are: drying temperature of 35-50℃ and material thickness of 1-3cm.

2. The preparation method according to claim 1, characterized in that, The porous carbon in step S1 is activated carbon or biochar, and / or the specific surface area of ​​the porous carbon is >1200 m². 2 / g, and / or iodine value >1000mg / g.

3. The preparation method according to claim 1, characterized in that, Step S1 further includes mixing and stirring porous carbon with dilute nitric acid solution, adjusting the pH value, washing and drying.

4. The preparation method according to any one of claims 1 to 3, characterized in that, In step S2, the organic solution containing N and P functional groups contains N functional groups, which are one or more of nitro, amino, cyano, pyrrole, or pyridine; more preferably, the N-containing compound is one or more of nitric acid, urea, nitrate ester, etc.; and / or In step S2, the organic solution containing N and P functional groups includes one or more of phosphine, phosphonic acid, and phosphonate esters; more preferably, the P-containing compound is one or more of phosphoric acid, potassium dihydrogen phosphate, and triphenylphosphine.

5. The preparation method according to any one of claims 1 to 4, characterized in that, Step S2 further includes dispersing the pretreated carrier from step S1 in an organic solution containing N and P functional groups, followed by ultrasonic vibration, cleaning, drying, and calcination.

6. The preparation method according to any one of claims 1 to 5, characterized in that, The metal salt in step S3 is one or more of Mg, Zn, or Mn salts; preferably, the metal salt in step S3 is a Zn salt; and / or The metal salt in step S3 is one or more of chloride, sulfate, nitrate, phosphate, and citrate.

7. The preparation method according to any one of claims 1 to 6, characterized in that, The metal salt in step S4 is one or more of Mn, Fe, Cu, Li, Co, Ni, or Rh salt; preferably, the metal salt in step S4 is Mn-Cu or Mn-Cu-Co.

8. A heterogeneous catalyst prepared by the method described in any one of claims 1 to 7.

9. The application of the heterogeneous catalyst as described in claim 8 in the catalytic ozone treatment of wastewater and / or waste liquid.

10. The use according to claim 9, characterized in that, The wastewater and / or waste liquid is leachate from old landfills or produced water from oil fields.

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