Deoxidizing catalyst, its preparation method and application

Abstract

The present application relates to oxygen-containing organic gas deoxidation and catalyst preparation technical field, disclose a kind of deoxidation catalyst and its preparation method and application.The deoxidation catalyst includes carrier and noble metal oxide supported on carrier, in the deoxidation catalyst, the weight ratio of noble metal element and the carrier is 0.05-3:100, the grain size of the active component of the deoxidation catalyst is 1-8nm.The deoxidation catalyst active component grain size provided in the present application is small, and the dispersion of active component in carrier is high, and the catalyst reactivity and single-pass service life are obviously improved.

Description

Technical Field

[0001] This invention relates to the field of oxygen-containing organic gas deoxygenation and catalyst preparation technology, specifically to a deoxygenation catalyst, its preparation method, and its application. Background Technology

[0002] The chemical industry is the cornerstone of modern people's production and life, satisfying people's demand for various chemical products. However, chemical processes involve many chemical reactions, among which oxidation is one of the most important. Due to incomplete reactions or side reactions, oxygen-containing organic gases or organic mixtures are often produced. High oxygen content in organic gases not only increases the risk of combustion and explosion, but also, according to SH3009-2013 "Design Specification for Combustible Gas Emission Systems in Petrochemical Industries," combustible gases with an oxygen content greater than 2% (v%) should not be discharged into the plant's overall combustible gas emission system. Therefore, the inherently safe handling of this tail gas has become a common concern for many researchers in academia and industry.

[0003] Catalytic deoxygenation technology removes oxygen from organic gases by enabling oxygen to react with other species through the action of a catalyst. This method offers advantages such as simple operation and significant effects, and is more feasible in many scenarios compared to adsorption deoxygenation and low-temperature separation deoxygenation. Catalyst design and screening are crucial steps in catalytic deoxygenation. Currently, active centers with deoxygenation functions include both noble and non-noble metal species, but noble metals, with their incomplete d orbitals, exhibit superior reactivity in catalytic reactions. In catalytic deoxygenation reactions, the reactivity of active species is influenced by their dispersion state. Generally, the smaller the crystal size and the more uniform the dispersion of the active center, the higher the catalyst's reactivity during the reaction.

[0004] CN 113304760 A discloses a highly dispersed platinum-based catalyst and its preparation method. A solution of a metal active component precursor solution and a support metal salt solution is dropwise added to a mixed solution of 1,3,5,-benzenetricarboxylic acid and an organic solvent at 20–80°C and stirred. A gel is then obtained through a hydration reaction. The highly dispersed platinum-based catalyst is obtained after drying, grinding, and calcination. CN 114130422 A discloses a method for preparing a deep deoxygenating silver X molecular sieve purifier. The inventors granulate the X molecular sieve after thoroughly mixing it with a binder, and then load Ag species onto the support. The catalyst obtained by this method has a high loading rate of active species and excellent deoxygenation effect. Liu Xiufang et al. prepared eggshell-shaped Pd / α-Al2O3 using an impregnation method and prepared catalysts with different palladium layer thicknesses by adjusting the pH of the precursor solution. The eggshell-shaped catalysts showed higher reactivity in the gas-phase synthesis of dimethyl oxalate from CO and methyl nitrite.

[0005] However, currently available highly dispersed supported catalysts are often prepared using complex methods, or their active centers are dispersed on the surface of the support. During the catalytic reaction, the active species are prone to aggregation, leading to a decrease in catalyst activity. Therefore, developing simple and easy-to-operate highly active catalysts with uniform dispersion of active species throughout the support is of great significance. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems of existing methods for preparing highly dispersed supported catalysts, which are complex or where active centers are dispersed on the surface of the support, leading to the aggregation of active species during the catalytic reaction and a decrease in catalyst activity. This invention provides a deoxygenation catalyst, its preparation method, and its application. This method is simple and easy to implement, resulting in a deoxygenation catalyst with small crystallite size, high dispersion of active components in the support, and significantly improved catalyst reactivity and single-pass lifespan.

[0007] To achieve the above objectives, the present invention provides a deoxygenation catalyst comprising a support and a noble metal oxide supported on the support, wherein the weight ratio of the noble metal element to the support in the deoxygenation catalyst is 0.05-3:100, and the grain size of the active component of the deoxygenation catalyst is 1-8 nm.

[0008] Preferably, the weight ratio of the precious metal element to the carrier is 0.08-2:100, more preferably 0.1-1:100.

[0009] Preferably, the carrier is selected from metal oxides, and more preferably from one or more of aluminum oxide, titanium dioxide, silicon dioxide and cerium dioxide.

[0010] Preferably, the noble metal oxide is selected from one or more of ruthenium, rhodium, palladium, osmium, iridium, platinum, gold and silver oxides, and more preferably from one or more of ruthenium, palladium and platinum oxides.

[0011] A second aspect of the present invention provides a method for preparing a deoxygenation catalyst, the method comprising the following steps:

[0012] (1) Mix the EDTA salt solution with the noble metal salt solution to obtain a mixed solution;

[0013] (2) The support is impregnated in the mixed solution, dried and calcined to obtain a deoxygenation catalyst;

[0014] The molar ratio of EDTA ions in the EDTA salt solution to the noble metal element in the noble metal salt solution is 0.1-10:1, and the weight ratio of the noble metal element in the noble metal salt solution to the carrier is 0.05-3:100.

[0015] Preferably, the molar ratio of EDTA ions in the EDTA salt solution to the noble metal element in the noble metal salt solution is 0.5-5:1, more preferably 0.5-3:1.

[0016] Preferably, the weight ratio of the precious metal element to the carrier is 0.08-2:100, more preferably 0.1-1:100.

[0017] Preferably, the EDTA salt solution is selected from disodium EDTA solution and / or dipotassium EDTA solution.

[0018] Preferably, the noble metal salt solution is selected from one or more of ruthenium, rhodium, palladium, osmium, iridium, platinum, gold and silver salt solutions, and more preferably from one or more of ruthenium, palladium and platinum oxides.

[0019] Preferably, the carrier is selected from metal oxides, and more preferably from one or more of aluminum oxide, titanium dioxide, silicon dioxide and cerium dioxide.

[0020] Preferably, the impregnation conditions include: an impregnation temperature of 0-40°C, more preferably 10-30°C, and even more preferably 20-30°C; and an impregnation time of 1-10 hours, more preferably 1-8 hours, and even more preferably 2-6 hours.

[0021] Preferably, the drying conditions include a temperature of 30-120°C, more preferably 40-100°C, and even more preferably 50-100°C.

[0022] Preferably, the roasting conditions include: a roasting temperature of 300-800℃, more preferably 400-600℃; and a roasting time of 1-6 hours, more preferably 2-4 hours.

[0023] The third aspect of this invention provides the application of the aforementioned deoxygenation catalyst and the deoxygenation catalyst prepared by the aforementioned method in coalbed methane deoxygenation, HPPO propylene oxide process tail gas deoxygenation, and ethylene oxide process tail gas deoxygenation.

[0024] The method of this invention stabilizes noble metal active species by using EDTA ions as a complexing agent. During the impregnation process, the stabilized metal species are less hindered by -OH species in the support (such as alumina, titanium dioxide, etc.), and can quickly disperse in the support. After impregnation for a certain period of time, a deoxygenation catalyst with uniformly dispersed noble metal active species can be obtained. The presence of the complexing agent affects the existence state of metal atoms in solution, and the prepared catalyst also has a smaller crystallite size. At the same time, by adjusting the ratio of complexing ions, catalysts with different concentrations of active species on the surface and at the center can be obtained. The active species at the center can exhibit activity in the later stages of the reaction, and the highly dispersed active species improve the stability of the catalyst. The method of this invention can simply and quickly prepare deoxygenation catalysts with uniformly dispersed active components on the support and small crystallite size, improving the catalytic activity and single-pass life of the catalyst. The method of this invention is highly operable, and the impregnation depth of the active species in the support can be controlled by simply adjusting the preparation method, thereby controlling the reaction activity. Attached Figure Description

[0025] Figure 1 This is the XRD pattern of the deoxygenation catalyst prepared in Example 1;

[0026] Figure 2 and Figure 3 This is a TEM image of the deoxygenation catalyst prepared in Example 1. Detailed Implementation

[0027] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0028] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0029] The present invention provides a deoxygenation catalyst comprising a support and a noble metal oxide supported on the support, wherein the weight ratio of the noble metal element to the support in the deoxygenation catalyst is 0.05-3:100, and the grain size of the active component of the deoxygenation catalyst is 1-8 nm.

[0030] In a preferred embodiment, the grain size of the active component of the deoxygenation catalyst is 2-5 nm.

[0031] In this invention, noble metal oxides are used as active components, the proportion of noble metal elements is appropriate, the active components are uniformly dispersed on the support, and the deoxygenation catalyst with small crystal size has high catalytic activity.

[0032] In a preferred embodiment, the weight ratio of the precious metal element to the carrier is 0.08-2:100. In a more preferred embodiment, the weight ratio of the precious metal element to the carrier is 0.1-1:100, for example, 0.1:100, 0.2:100, 0.3:100, 0.4:100, 0.5:100, 0.6:100, 0.7:100, 0.8:100, 0.9:100, or 1:100.

[0033] In the deoxygenation catalyst of the present invention, the support can be a metal oxide conventionally used in the art. In a preferred embodiment, the support is one or more of alumina, titanium dioxide, silicon dioxide, and cerium dioxide.

[0034] In the deoxygenation catalyst of the present invention, the active component can be selected from noble metal oxides conventionally used in the art, specifically, for example, one or more of ruthenium, rhodium, palladium, osmium, iridium, platinum, gold, and silver oxides. In a preferred embodiment, the active component is one or more of ruthenium, palladium, and platinum oxides.

[0035] A second aspect of the present invention provides a method for preparing a deoxygenation catalyst, the method comprising the following steps:

[0036] (1) Mix the EDTA salt solution with the noble metal salt solution to obtain a mixed solution;

[0037] (2) The support is impregnated in the mixed solution, dried and calcined to obtain a deoxygenation catalyst;

[0038] The molar ratio of EDTA ions in the EDTA salt solution to the noble metal element in the noble metal salt solution is 0.1-10:1, and the weight ratio of the noble metal element in the noble metal salt solution to the carrier is 0.05-3:100.

[0039] In the method described in this invention, by reasonably controlling the raw material ratio and using specific methods, the resulting catalyst can have a smaller crystal size. At the same time, the active components are uniformly dispersed in the catalyst support, thereby improving the catalytic activity and single-pass reaction life of the catalyst.

[0040] In a preferred embodiment, the molar ratio of EDTA ions in the EDTA salt solution to the noble metal element in the noble metal salt solution is 0.5-5:1. In a more preferred embodiment, the molar ratio of EDTA ions in the EDTA salt solution to the noble metal element in the noble metal salt solution is 1-3:1, for example, 1:1, 1.5:1, 2:1, 2.5:1 or 3:1.

[0041] In a preferred embodiment, the weight ratio of the precious metal element to the carrier is 0.08-2:100. In a more preferred embodiment, the weight ratio of the precious metal element to the carrier is 0.1-1:100, for example, 0.1:100, 0.2:100, 0.3:100, 0.4:100, 0.5:100, 0.6:100, 0.7:100, 0.8:100, 0.9:100, or 1:100.

[0042] In the method described in this invention, the EDTA salt solution can be any conventional choice in the art. In a preferred embodiment, the EDTA salt solution is selected from disodium EDTA solution and / or dipotassium EDTA solution.

[0043] In the method described in this invention, the noble metal salt solution can be any conventionally chosen material in the art. In specific embodiments, the noble metal salt solution can be selected from one or more of ruthenium, rhodium, palladium, osmium, iridium, platinum, gold, and silver salt solutions. In a preferred embodiment, the noble metal salt solution is one or more of ruthenium, palladium, and platinum oxides. In specific embodiments, the noble metal salt solution can be a nitrate solution or a chloride solution. The noble metal source used to prepare the noble metal salt solution can be any commercially available form; for example, the palladium source used to prepare the palladium salt solution can be a commercially available palladium nitrate solution diluted or directly dissolved from purchased palladium nitrate dihydrate powder.

[0044] In the method described in this invention, the support can be a metal oxide conventionally used in the art. In a preferred embodiment, the support is one or more of alumina, titanium dioxide, silicon dioxide, and cerium dioxide.

[0045] In the method of the present invention, the impregnation temperature can be 0-40°C, preferably 10-30°C, more preferably 20-30°C, for example 20°C, 25°C or 30°C. In the method of the present invention, the impregnation time can be 1-10 hours, preferably 1-8 hours, more preferably 2-6 hours, for example 2 hours, 3 hours, 4 hours, 5 hours or 6 hours.

[0046] In the method described in this invention, the drying temperature can be 30-120℃, preferably 40-100℃, more preferably 50-100℃, for example 50℃, 60℃, 70℃, 80℃, 90℃ or 100℃.

[0047] In the method of the present invention, the calcination temperature can be 300-800℃, preferably 400-600℃, for example 400℃, 450℃, 500℃, 550℃ or 600℃. In the method of the present invention, the calcination time can be 1-6 hours, preferably 2-4 hours, for example 2 hours, 3 hours or 4 hours.

[0048] The third aspect of this invention provides the application of the aforementioned deoxygenation catalyst and the deoxygenation catalyst prepared by the aforementioned method in coalbed methane deoxygenation, HPPO propylene oxide process tail gas deoxygenation, and ethylene oxide process tail gas deoxygenation.

[0049] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited thereto.

[0050] Example 1

[0051] (1) Mix 3.75g of palladium nitrate solution (palladium content is 4wt%) with 7.18g of 10wt% disodium EDTA solution to obtain a mixed solution. The molar ratio of EDTA ions in the disodium EDTA solution to palladium in the palladium nitrate solution is 1.5:1.

[0052] (2) 50g of alumina balls were immersed in the mixed solution at room temperature (25℃) for 5h. The weight ratio of palladium element in palladium nitrate solution to alumina balls was 0.3:100. Then the mixture was dried at 50℃ and calcined at 500℃ for 3h to obtain the deoxygenation catalyst.

[0053] The XRD pattern of the deoxygenation catalyst prepared in Example 1 is shown below. Figure 1 As shown. From Figure 1 It can be seen that no other diffraction peaks appeared besides the diffraction peaks of the carrier.

[0054] TEM images of the deoxygenation catalyst prepared in Example 1 are shown below. Figure 2 and Figure 3 As shown. From Figure 2 and Figure 3 It can be seen that the crystal size of the active component is between 2-5 nm and it exhibits a relatively uniform dispersion, which is of positive significance for improving the reaction activity of the catalyst.

[0055] Example 2

[0056] (1) Mix 12.5g of palladium nitrate solution (palladium content is 2wt%) with 31.8g of 10wt% EDTA disodium solution to obtain a mixed solution. The molar ratio of EDTA ions in the EDTA disodium solution to palladium in the palladium nitrate solution is 4:1.

[0057] (2) 50g of cerium dioxide was immersed in the mixed solution at room temperature (25℃) for 5h. The weight ratio of palladium element in palladium nitrate solution to alumina balls was 0.5:100. Then it was dried at 50℃ and calcined at 500℃ for 3h to obtain the deoxygenation catalyst.

[0058] Example 3

[0059] (1) Mix 5g of palladium nitrate solution (palladium content is 1wt%) with 2g of 20wt% EDTA disodium solution to obtain a mixed solution. The molar ratio of EDTA ions in the EDTA disodium solution to palladium in the palladium nitrate solution is 2.5:1.

[0060] (2) 10g of alumina balls were immersed in the mixed solution at room temperature (25℃) for 5h. The weight ratio of palladium element in the palladium nitrate solution to alumina balls was 0.5:100. Then the solution was dried at 50℃ and calcined at 500℃ for 3h to obtain the deoxygenation catalyst.

[0061] Example 4

[0062] (1) Mix 5g of palladium nitrate solution (palladium content is 1wt%) with 15.9g of 10wt% EDTA disodium solution to obtain a mixed solution. The molar ratio of EDTA ions in the EDTA disodium solution to palladium in the palladium nitrate solution is 10:1.

[0063] (2) 50g of titanium dioxide was immersed in the mixed solution at room temperature (25℃) for 5h. The weight ratio of palladium element in palladium nitrate solution to alumina balls was 0.1:100. Then it was dried at 50℃ and calcined at 400℃ for 3h to obtain deoxygenation catalyst.

[0064] Example 5

[0065] (1) Mix 6.25g of ruthenium chloride solution (ruthenium content is 4wt%) with 8.36g of 10wt% EDTA disodium solution to obtain a mixed solution. The molar ratio of EDTA ions in the EDTA disodium solution to ruthenium in the ruthenium chloride solution is 1:1.

[0066] (2) 25g of silicon dioxide was immersed in the mixed solution at room temperature (25℃) for 2h. The weight ratio of ruthenium element in the ruthenium chloride solution to the amount of alumina balls was 1:100. Then it was dried at 100℃ and calcined at 400℃ for 3h to obtain the deoxygenation catalyst.

[0067] Example 6

[0068] The method is implemented according to Example 3, except that in step (2), the calcination temperature is 700°C. The specific method is as follows:

[0069] (1) Mix 5g of palladium nitrate solution (palladium content is 1wt%) with 2g of 20wt% EDTA disodium solution to obtain a mixed solution. The molar ratio of EDTA ions in the EDTA disodium solution to palladium in the palladium nitrate solution is 2.5:1.

[0070] (2) 10g of alumina balls were immersed in the mixed solution at room temperature (25℃) for 5h. The weight ratio of palladium element in palladium nitrate solution to alumina balls was 0.5:100. Then the mixture was dried at 50℃ and calcined at 700℃ for 3h to obtain the deoxygenation catalyst.

[0071] Example 7

[0072] The method was implemented according to Example 3, except that in step (2), the calcination time was 5 hours. The specific method is as follows:

[0073] (1) Mix 5g of palladium nitrate solution (palladium content is 1wt%) with 2g of 20wt% EDTA disodium solution to obtain a mixed solution. The molar ratio of EDTA ions in the EDTA disodium solution to palladium in the palladium nitrate solution is 2.5:1.

[0074] (2) 10g of alumina balls were immersed in the mixed solution at room temperature (25℃) for 5h. The weight ratio of palladium element in palladium nitrate solution to alumina balls was 0.5:100. Then the mixture was dried at 50℃ and calcined at 500℃ for 5h to obtain the deoxygenation catalyst.

[0075] Example 8

[0076] The method is implemented according to Example 3, except that in step (2), the soaking time is 8 hours. The specific method is as follows:

[0077] (1) Mix 5g of palladium nitrate solution (palladium content is 1wt%) with 2g of 20wt% EDTA disodium solution to obtain a mixed solution. The molar ratio of EDTA ions in the EDTA disodium solution to palladium in the palladium nitrate solution is 2.5:1.

[0078] (2) 10g of alumina balls were immersed in the mixed solution at room temperature (25℃) for 8h. The weight ratio of palladium element in the palladium nitrate solution to alumina balls was 0.5:100. Then the mixture was dried at 50℃ and calcined at 500℃ for 3h to obtain the deoxygenation catalyst.

[0079] Example 9

[0080] The method described in Example 3 was followed, except that the carrier was titanium dioxide. The specific method is as follows:

[0081] (1) Mix 5g of palladium nitrate solution (palladium content is 1wt%) with 2g of 20wt% EDTA disodium solution to obtain a mixed solution. The molar ratio of EDTA ions in the EDTA disodium solution to palladium in the palladium nitrate solution is 2.5:1.

[0082] (2) 10g of titanium dioxide was immersed in the mixed solution at room temperature (25℃) for 5h. The weight ratio of palladium element in palladium nitrate solution to alumina balls was 0.5:100. Then it was dried at 50℃ and calcined at 500℃ for 3h to obtain deoxygenation catalyst.

[0083] Example 10

[0084] The method was implemented according to Example 1, except that the carrier was silicon dioxide. The specific method is as follows:

[0085] (1) Mix 3.75g of palladium nitrate solution (palladium content is 4wt%) with 7.18g of 10wt% disodium EDTA solution to obtain a mixed solution. The molar ratio of EDTA ions in the disodium EDTA solution to palladium in the palladium nitrate solution is 1.5:1.

[0086] (2) 50g of silicon dioxide was immersed in the mixed solution at room temperature (25℃) for 5h. The weight ratio of palladium element in palladium nitrate solution to alumina balls was 0.3:100. Then it was dried at 50℃ and calcined at 500℃ for 3h to obtain deoxygenation catalyst.

[0087] Example 11

[0088] The method was implemented according to Example 1, except that the weight ratio of palladium element in the palladium nitrate solution to alumina balls was 2:100. The specific method is as follows:

[0089] (1) Mix 3.75g of palladium nitrate solution (palladium content is 4wt%) with 7.18g of 10wt% disodium EDTA solution to obtain a mixed solution. The molar ratio of EDTA ions in the disodium EDTA solution to palladium in the palladium nitrate solution is 1.5:1.

[0090] (2) 7.5g of alumina balls were immersed in the mixed solution at room temperature (25℃) for 5h. The weight ratio of palladium element in the palladium nitrate solution to alumina balls was 2:100. Then the solution was dried at 50℃ and calcined at 500℃ for 3h to obtain the deoxygenation catalyst.

[0091] Comparative Example 1

[0092] The method was implemented according to Example 1, except that the molar ratio of EDTA ions in the disodium EDTA solution to palladium in the palladium nitrate solution was 0.05:1.

[0093] Test case

[0094] The reaction activity and single-pass lifespan of the catalysts prepared in the test examples and comparative examples were examined. The catalyst reaction activity was tested as follows: the feed gas was propylene gas containing 3% O2; the reaction conditions were 260℃ and 0.5 MPa. Under these conditions, the initial deoxidation rate and catalyst reaction lifespan were tested. The single-pass lifespan of the catalyst described in this invention is calculated as the time required for the catalyst to reach 90% of the initial deoxidation rate without changing the reaction conditions. The test results are shown in Table 1.

[0095] Table 1

[0096] Example 1 91 850 Example 2 90 900 Example 3 92 860 Example 4 85 750 Example 5 84 800 Example 6 90 750 Example 7 93 860 Example 8 92 840 Example 9 79 700 Example 10 89 760 Example 11 96 1050 Comparative Example 1 71 550

[0097] As can be seen from Table 1, the deoxygenation catalyst prepared by the method described in this invention has excellent initial deoxygenation rate and single-pass lifespan.

[0098] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. The application of a deoxygenation catalyst, characterized in that, The deoxygenation catalyst includes a support and a noble metal oxide supported on the support. In the deoxygenation catalyst, the weight ratio of the noble metal element to the support is 0.05-3:100, and the grain size of the active component of the deoxygenation catalyst is 1-8 nm. The preparation method of the deoxygenation catalyst includes the following steps: (1) Mix the EDTA salt solution with the noble metal salt solution to obtain a mixed solution; (2) The support is impregnated in the mixed solution, dried and calcined to obtain a deoxygenation catalyst; Wherein, the molar ratio of EDTA ions in the EDTA salt solution to the noble metal element in the noble metal salt solution is 0.1-10:1, and the weight ratio of the noble metal element in the noble metal salt solution to the carrier is 0.05-3:

100. The carrier is aluminum oxide, titanium dioxide, or cerium dioxide; The reaction activity test process of the deoxygenation catalyst is as follows: the feed gas is propylene gas containing 3% O2, and the reaction conditions are: 260℃, 0.5MPa.

2. The application according to claim 1, characterized in that, The weight ratio of the precious metal element to the carrier is 0.08-2:

100.

3. The application according to claim 2, characterized in that, The weight ratio of the precious metal element to the carrier is 0.1-1:

100.

4. The application according to claim 1, characterized in that, The precious metal oxide is selected from one or more of ruthenium, rhodium, palladium, osmium, iridium, platinum, gold and silver oxides.

5. The application according to claim 4, characterized in that, The noble metal oxide is selected from one or more of ruthenium, palladium and platinum oxides.

6. The application according to claim 1, characterized in that, The molar ratio of EDTA ions in the EDTA salt solution to the noble metal element in the noble metal salt solution is 0.5-5:

1.

7. The application according to claim 6, characterized in that, The molar ratio of EDTA ions in the EDTA salt solution to the noble metal element in the noble metal salt solution is 1-3:

1.

8. The application according to claim 1, characterized in that, The EDTA salt solution is selected from disodium EDTA solution and / or dipotassium EDTA solution.

9. The application according to claim 1, characterized in that, The precious metal salt solution is selected from one or more of ruthenium, rhodium, palladium, osmium, iridium, platinum, gold and silver salt solutions.

10. The application according to claim 1, characterized in that, The conditions for immersion include: immersion temperature of 0-40℃; immersion time of 1-10 hours.

11. The application according to claim 10, characterized in that, The impregnation temperature is 10-30℃.

12. The application according to claim 11, characterized in that, The impregnation temperature is 20-30℃.

13. The application according to claim 10, characterized in that, The soaking time is 1-8 hours.

14. The application according to claim 13, characterized in that, The soaking time is 2-6 hours.

15. The application according to claim 1, characterized in that, The drying conditions include a temperature of 30-120°C.

16. The application according to claim 15, characterized in that, The roasting conditions include: a roasting temperature of 300-800℃ and a roasting time of 1-6 hours.

17. The application according to claim 16, characterized in that, The roasting temperature is 400-600℃.

18. The application according to claim 16, characterized in that, The roasting time is 2-4 hours.

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