Method for preparing supported nanoparticle catalyst by wet ball milling

Abstract

The invention relates to the technical field of catalyst preparation, in particular to a method for preparing a supported nanoparticle catalyst by wet ball milling. According to the method, high-energy mixing between the metal phase and the carrier is promoted through the action of mechanical force, efficient loading of the metal phase on the surface of the carrier is achieved, meanwhile, high-temperature treatment is not needed, agglomeration of nano-particles is effectively avoided, and therefore the catalytic performance of the catalyst is improved. Secondly, the inert protective atmosphere is used, so that oxidation and other side reactions are avoided, and the active state of the metal and the stability of the carrier are kept. Compared with a traditional method, wet ball milling is adopted, and the preparation process of the catalyst is greatly simplified. In addition, the loading capacity of metal particles in a traditional method is low; according to the method, the loading capacity of the nanoparticles containing the metal elements can be improved, and the maximum loading capacity reaches 20%.

Description

Technical Field

[0001] The present invention relates to the technical field of catalyst preparation, and in particular to a method for preparing a supported nanoparticle catalyst by utilizing wet ball milling. Background Art

[0002] Supported nanoparticle catalysts have been a hot topic in catalysis research in recent years. They achieve enhanced catalytic activity, selectivity, and stability by loading active metal nanoparticles onto high-surface-area supports. Common supported catalyst supports include metal oxides (such as titanium oxide, aluminum oxide, and zirconium oxide), carbon-based materials, and molecular sieves. These catalysts are widely used in fields such as petrochemicals, environmental catalysis, and new energy.

[0003] Currently, the main method for preparing supported nanoparticle catalysts is chemical methods. These methods include solvothermal, coprecipitation, and sol-gel methods. While these methods can effectively control the morphology of nanoparticles, they also suffer from complex procedures and uneven distribution of metal nanoparticles on the support. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a method for preparing a supported nanoparticle catalyst by wet ball milling. The loading method of the present invention is simple and efficient, and can achieve uniform loading of metal phase nanoparticles.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing a supported nanoparticle catalyst by wet ball milling, comprising the following steps:

[0007] The carrier, the metal phase and the solvent are wet ball-milled under the protection of an inert gas to obtain the supported nanoparticle catalyst; the supported nanoparticle catalyst comprises a carrier and metal phase nanoparticles supported on the carrier.

[0008] Preferably, the support comprises one or more of metal oxides, SiO2, molecular sieves and Si3N4.

[0009] Preferably, the metal oxide includes one or more of TiO2, Al2O3, ZrO2 and MgO; the molecular sieve includes one or more of ZSM-5 molecular sieve, MCM-41 molecular sieve and SBA-15 molecular sieve.

[0010] Preferably, the metal phase includes one or more of transition metal oxides, transition metal nitrates, transition metal acetates, noble metal elements, and transition metal elements.

[0011] Preferably, the transition metal elements in the transition metal oxide, transition metal nitrate, transition metal acetate and transition metal element independently include one or more of Fe, Co, Ni, Cu, Mn, Zn, Ti and Mo; and the precious metal element includes one or more of Pt, Pd, Rh, Au and Ir.

[0012] Preferably, the mass ratio of the carrier to the metal phase is 5 to 20:1.

[0013] Preferably, a surfactant is added during the wet ball milling; the mass ratio of the total mass of the carrier and the metal phase to the surfactant is 1000:1-5.

[0014] Preferably, the solvent includes one or more of water, acetone and alcohol solvents.

[0015] Preferably, the volume ratio of the total mass of the carrier and the metal phase to the polar solvent is 1 g: 1 to 10 mL.

[0016] Preferably, the rotation speed of the wet ball milling is 100-1500 rpm, the time is 0.5-48 h, and the ball-to-material ratio is 10-100:1.

[0017] The present invention provides a method for preparing a supported nanoparticle catalyst by wet ball milling, comprising the following steps: wet ball milling a support, a metal phase and a solvent under the protection of an inert gas to obtain the supported nanoparticle catalyst; the supported nanoparticle catalyst comprises a support and metal phase nanoparticles supported on the support.

[0018] The present invention utilizes wet ball milling to prepare a supported nanoparticle catalyst. The process promotes high-energy mixing of the metal phase and the carrier through mechanical force, while simultaneously refining the metal phase particles to achieve the loading of the metal phase nanoparticles. Because no high-temperature treatment is required, and the solvent in the wet ball milling can act as a cooling medium to slow down heat accumulation, combined with the dispersing effect of the solvent, it effectively avoids nanoparticle agglomeration, thereby improving the catalytic performance of the catalyst. Secondly, the use of an inert protective atmosphere avoids the occurrence of oxidation and other side reactions, maintaining the active state of the metal phase and the stability of the carrier. Compared with traditional methods, the present invention adopts wet ball milling, which greatly simplifies the preparation process of the catalyst.

[0019] In addition, the loading amount of metal particles in the traditional method is low (generally <5%); the present invention can increase the loading amount of nanoparticles containing metal elements to a maximum of 20%.

[0020] Furthermore, by adjusting the ball milling time and parameters, the present invention can precisely control the particle size of the supported metallic nanoparticles, resulting in a catalyst with higher activity and selectivity, meeting the requirements of different catalytic reactions. The method of the present invention not only exhibits excellent catalytic performance but also significantly reduces preparation costs, offering broad application prospects, particularly in the fields of petrochemicals, environmental catalysis, and new energy, effectively improving catalytic efficiency and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Spherical aberration-corrected scanning transmission electron microscopy (Cs-STEM) images of titanium dioxide-supported HCP-Co nanoparticles prepared in Example 1 at different positions and magnifications;

[0022] Figure 2 This is an elemental mapping image of the titanium dioxide-supported HCP-Co nanoparticles prepared in Example 1;

[0023] Figure 3 Cs-STEM images of titanium dioxide-supported Co3O4 nanoparticles prepared in Example 2 at different positions and magnifications;

[0024] Figure 4 This is an elemental mapping image of titanium dioxide-supported Co3O4 nanoparticles prepared in Example 2;

[0025] Figure 5 Cs-STEM images of titanium dioxide-supported FCC-Co nanoparticles prepared in Example 3 at different positions and magnifications;

[0026] Figure 6 This is an elemental mapping image of titanium dioxide-supported FCC-Co nanoparticles prepared in Example 3;

[0027] Figure 7 Cs-STEM images of titanium dioxide-supported HCP-Co nanoparticles prepared in Example 4 at different positions and magnifications;

[0028] Figure 8 This is an elemental mapping image of titanium dioxide-supported HCP-Co nanoparticles prepared in Example 4;

[0029] Figure 9 Cs-STEM image of the TiO2@Co catalyst prepared in Comparative Example 1;

[0030] Figure 10 This is the elemental mapping image of the TiO2@Co catalyst prepared in Comparative Example 1. DETAILED DESCRIPTION

[0031] The present invention provides a method for preparing a supported nanoparticle catalyst by wet ball milling, comprising the following steps:

[0032] The carrier, the metal phase and the solvent are wet ball-milled under the protection of an inert gas to obtain the supported nanoparticle catalyst; the supported nanoparticle catalyst comprises a carrier and metal phase nanoparticles supported on the carrier.

[0033] In the present invention, unless otherwise specified, all raw materials used are commercially available products well known in the art.

[0034] In the present invention, the carrier preferably includes one or more of metal oxides, SiO2, molecular sieves, and Si3N4; the metal oxide preferably includes one or more of TiO2, Al2O3, ZrO2, and MgO; and the molecular sieve preferably includes one or more of ZSM-5 molecular sieve, MCM-41 molecular sieve, and SBA-15 molecular sieve. In the present invention, the particle size of the carrier is preferably 100 to 500 nm, and in specific embodiments, it can be 100 nm, 200 nm, 300 nm, 400 nm, or 500 nm.

[0035] The above-mentioned support materials have excellent chemical stability, high specific surface area and good mechanical strength, and play an important role in the preparation process of catalysts. Specifically, TiO2, as a widely used photocatalytic material, has strong light absorption ability and long excited state lifetime, and is often used in photocatalytic reactions. Al2O3 and SiO2 are common acidic catalyst supports, widely used in petrochemicals, catalytic cracking and other fields. ZrO2 is widely used in high-temperature catalytic reactions due to its high thermal stability, especially for catalytic conversion reactions. ZSM-5 and MCM-41 molecular sieves have unique advantages in the synthesis of fine chemicals and catalytic cracking reactions due to their special pore structure. SBA-15 molecular sieve, as a macroporous material, is often used in macromolecular reactions, and Si3N4 is suitable for harsh reaction environments due to its excellent high temperature resistance.

[0036] In the present invention, the metal phase includes one or more of transition metal oxides, transition metal nitrates, transition metal acetates, noble metal elements, and transition metal elements; the transition metal oxides, transition metal nitrates, transition metal acetates, and transition metal elements independently preferably include one or more of Fe, Co, Ni, Cu, Mn, Zn, Ti, and Mo; the noble metal element preferably includes one or more of Pt, Pd, Rh, Au, and Ir. Those skilled in the art can select a suitable metal phase and crystal form according to actual needs. In an embodiment of the present invention, the metal phase is HCP-Co (i.e., a hexagonal close-packed Co element) or Co3O4. Before wet ball milling, the particle size of the noble metal element and the transition metal element is independently preferably 10 to 200 nm; the present invention does not specifically limit the particle size of the transition metal oxides, transition metal nitrates, and transition metal acetates, and any commercially available powder products known in the art can be used.

[0037] Precious metal elements such as Pt, Pd, Rh, Au, and Ir are widely used in fields such as hydrogenation reactions, catalytic cracking, and fuel cells, and have high catalytic activity and excellent selectivity. Transition metal elements such as Fe, Co, Ni, Mo, and Cu are commonly used in catalytic reactions such as hydrogenation and oxidation, and are relatively inexpensive and economical. The present invention, through the rational selection of different metal elements, can achieve catalyst functionalization and optimize its catalytic performance and reaction selectivity.

[0038] In the present invention, the mass ratio of the support to the metal phase is preferably 5 to 20:1, and in specific embodiments may be 5:1, 8:1, 10:1, 15:1 or 20:1.

[0039] In the present invention, the solvent preferably includes one or more of water, acetone and alcohol solvents; the alcohol solvent preferably includes one or more of ethanol, isopropanol and ethylene glycol. In the present invention, the volume ratio of the total mass of the carrier and the metal phase to the polar solvent is preferably 1g:1~10mL, and in specific embodiments it can be 1g:1mL, 1g:2mL, 1g:3mL, 1g:5mL, 1g:6mL, 1g:8mL or 1g:10mL. In the present invention, the solvent can effectively disperse and stabilize the particles, reduce direct collisions between particles, and reduce the possibility of agglomeration. In addition, the solvent also has the function of acting as a cooling medium, which can slow down the accumulation of heat during the ball milling process, and at the same time provide a certain surface tension to prevent the particles from sticking together.

[0040] In the present invention, a surfactant is preferably added during the wet ball milling process. The surfactant preferably includes one or more of polyvinyl pyrrolidone, polyethylene glycol, citric acid, and sodium lauryl sulfate. The mass ratio of the total mass of the carrier and the metal phase to the surfactant is preferably 1000:1 to 5, and in specific embodiments, can be 1000:1, 1000:2, 1000:3, 1000:4, or 1000:5. In the present invention, the surfactant further enhances the dispersion of the metal phase.

[0041] The present invention preferably mixes the components to obtain a mixed slurry and then wet-ball mills the mixed slurry. The present invention has no special requirements for the preparation process of the mixed slurry, and the raw materials can be directly mixed, specifically, with or without stirring.

[0042] After obtaining the mixed slurry, the present invention performs wet ball milling on the mixed slurry under the protection of inert gas, and the size of the metal phase is further reduced and loaded onto the carrier to obtain the supported nanoparticle catalyst.

[0043] In the present invention, the inert gas preferably includes nitrogen, argon or an argon-hydrogen mixture. The inert gas protection used in the present invention can effectively prevent oxidation of the sample during the ball milling process, ensure the purity of the final product, and improve the stability and reactivity of the material to a certain extent.

[0044] In the present invention, the ball mill used for the wet ball milling process preferably includes one or more of a planetary ball mill, a grate ball mill, a short-tube ball mill, a long-tube ball mill, a center-drive ball mill, and an edge-drive ball mill. These ball mills have different structural features and energy transmission methods, and can be flexibly selected based on specific experimental requirements to achieve efficient ball milling and meet the processing requirements of different materials.

[0045] In the present invention, the ball mill jar used for wet ball milling is preferably made of one of stainless steel, cemented carbide, aluminum alloy, zirconium oxide, aluminum oxide, zirconium silicate, agate, polyurethane, and nylon. Ball mill jars made of these materials offer high mechanical strength and wear resistance, as well as excellent chemical stability, effectively preventing material contamination during the milling process. Furthermore, selecting the appropriate ball mill jar material, based on the properties of the materials and experimental requirements, can optimize milling efficiency and improve the quality of the final product.

[0046] In the present invention, the ball milling beads used in the wet ball milling process are preferably made of one or more of zirconium oxide, aluminum oxide, zirconium silicate, agate, steel (such as stainless steel and high-chromium steel), cemented carbide, glass, silicon nitride, and polymer materials (such as polyurethane and nylon). Ball milling beads made of these materials have excellent mechanical properties and chemical stability, ensuring thorough grinding and uniform mixing of the sample during the ball milling process.

[0047] In the present invention, the diameter of the ball milling beads preferably includes one or more of 3 mm, 5 mm, 6 mm, 8 mm, 10 mm, and 15 mm. By properly selecting the diameter of the ball milling beads, the present invention can effectively optimize ball milling efficiency, ensure grinding uniformity, and meet the requirements of different materials and processing precision.

[0048] In the present invention, the rotation speed of the wet ball milling is preferably 100-1500 rpm, and in specific embodiments, it can be 100 rpm, 300 rpm, 500 rpm, 800 rpm, 1000 rpm, 1200 rpm or 1500 rpm; the time of the wet ball milling is preferably 0.5-48 h, and in specific embodiments, it can be 0.5 h, 2 h, 5 h, 10 h, 15 h, 20 h, 25 h, 30 h, 35 h, 40 h or 48 h; the ball-to-material ratio of the wet ball milling is preferably 10-100:1, and in specific embodiments, it can be 10:1, 20:1, 30:1, 40:1, 50:1, 60:1, 80:1 or 100:1.

[0049] After the wet ball milling is completed, the present invention preferably further comprises: removing the solvent from the obtained material, and drying to obtain the supported nanoparticle catalyst.

[0050] The present invention uses wet ball milling to efficiently refine the metal phase and evenly disperse it on the carrier, thereby achieving efficient catalyst preparation. The method provided by the present invention is not only simple to operate and has a stable process, but also can be flexibly adapted to the processing requirements of different materials by adjusting the ball milling parameters, providing technical support for large-scale, low-cost catalyst production.

[0051] The method for preparing supported nanoparticle catalysts by wet ball milling provided by the present invention is described in detail below with reference to the examples, but they should not be construed as limiting the scope of protection of the present invention.

[0052] Example 1

[0053] 200mg of HCP-Co (20nm particle size) and 800mg of titanium dioxide (30nm particle size) were weighed, 5mL of deionized water was added, and the mixture was stirred thoroughly to mix thoroughly. Subsequently, the mixed slurry was transferred to a ball mill (made of ZrO2), 10 10mm diameter zirconium oxide ball milling beads (ball-to-material ratio of 30:1) were added, and nitrogen was purged into the mill for 10 minutes. The ball milling time was set for 14 hours at a planetary ball mill speed of 800rpm. After ball milling, the solvent was evaporated and then dried to obtain titanium dioxide-loaded HCP-Co nanoparticles with a loading of up to 20%.

[0054] Figure 1 Spherical aberration corrected scanning transmission electron microscopy (Cs-STEM) images of titanium dioxide loaded HCP-Co nanoparticles prepared in Example 1 at different positions and magnifications (Note: Figure 1 Although the scales in each figure are all 5 nm, the lengths of the scales are different, which also represent different magnifications (the same applies below). Figure 1 It can be observed that the Co nanoparticles are evenly distributed on the surface of the titanium dioxide support. The size of the Co nanoparticles is about 2 nm and has good dispersibility, indicating that the synthesis method adopted has a high controllability.

[0055] Figure 2 Elemental mapping image of titanium dioxide supported HCP-Co nanoparticles prepared in Example 1, from Figure 2 It can be seen that the Ti, O, and Co elements are evenly distributed throughout the particle area, with no obvious element aggregation observed. This indicates that the Co element has been successfully loaded onto the TiO2 support surface and is evenly distributed, which is conducive to the full exposure and utilization of catalytic active sites and provides a good foundation for subsequent performance testing.

[0056] Example 2

[0057] Weigh 273 mg of Co3O4 (particle size 20 nm) and 727 mg of titanium dioxide (particle size 25 nm), add 5 mL of isopropanol, and stir thoroughly to mix the two. Subsequently, the mixed slurry is transferred to a ball mill (made of stainless steel), 10 stainless steel ball milling beads with a diameter of 8 mm (ball to material ratio of 50:1) are added, and argon gas is introduced into the ball mill for 10 minutes. The ball milling time is set to 12 hours and the speed of the planetary ball mill is set to 900 rpm. After the ball milling is completed, the solvent is evaporated and then dried to obtain titanium dioxide-loaded Co3O4 nanoparticles with a Co loading of up to 20%.

[0058] Figure 3 The Cs-STEM images of titanium dioxide-loaded Co3O4 nanoparticles prepared in Example 2 at different positions and magnifications. Figure 3 It can be observed that Co3O4 nanoparticles are evenly distributed on the surface of the titanium dioxide support. The size of the Co3O4 nanoparticles is about 2nm and has good dispersibility, indicating that the synthesis method adopted has a high control ability.

[0059] Figure 4 Elemental mapping image of titanium dioxide loaded Co3O4 nanoparticles prepared in Example 2, from Figure 4 It can be seen that the Ti, O, and Co elements are evenly distributed throughout the particle area, and no obvious element aggregation is observed. This shows that Co3O4 has been successfully loaded on the surface of the TiO2 support and is evenly distributed.

[0060] Example 3

[0061] Weigh 200mg of FCC-Co (particle size 35nm) and 800mg of titanium dioxide (particle size 40nm), add 5mL of ethanol, and stir thoroughly to mix the two. Subsequently, the mixture is transferred to a ball mill (made of ZrO2), and one mixed zirconium oxide ball milling bead with a diameter of 10mm, two diameters of 8mm, four diameters of 6mm, and six diameters of 3mm is added (ball-to-material ratio of 40:1). A mixture of argon and nitrogen is passed through the ball mill for 10 minutes. The ball milling time is set to 24h and the speed of the planetary ball mill is set to 600rpm. After the ball milling is completed, the solvent is evaporated and then dried to obtain titanium dioxide-loaded FCC-Co nanoparticles with a loading of up to 20%.

[0062] Figure 5 Cs-STEM images of titanium dioxide-supported FCC-Co nanoparticles prepared in Example 3 at different positions and magnifications. Figure 5 It can be observed that the Co nanoparticles are evenly distributed on the surface of the titanium dioxide support. The size of the Co nanoparticles is about 2 nm and has good dispersibility, indicating that the synthesis method adopted has a high controllability.

[0063] Figure 6 Elemental mapping image of titanium dioxide supported FCC-Co nanoparticles prepared in Example 3, from Figure 6 It can be seen that the Ti, O, and Co elements are evenly distributed throughout the particle area, with no obvious element aggregation observed. This indicates that the Co element has been successfully loaded on the surface of the TiO2 support and is evenly distributed, which is conducive to the full exposure and utilization of catalytic active sites.

[0064] Example 4

[0065] Weigh 200mg of HCP-Co (particle size 30nm) and 800mg of titanium dioxide (particle size 30nm), add 5mL of acetone, add 5mg of polyvinyl alcohol, and stir thoroughly to mix the two. Subsequently, the mixed slurry is transferred to a ball mill (made of ZrO2), 10 zirconia ball milling beads with a diameter of 10mm (ball-to-material ratio of 30:1) are added, and nitrogen is introduced into the ball mill for 10 minutes. The ball milling time is set to 14h and the speed of the planetary ball mill is set to 800rpm. After the ball milling is completed, the solvent is evaporated and then dried to obtain titanium dioxide-loaded HCP-Co nanoparticles with a loading of up to 20%.

[0066] Figure 7 Cs-STEM images of titanium dioxide-supported HCP-Co nanoparticles prepared in Example 4 at different positions and magnifications. Figure 7It can be observed that the Co nanoparticles are evenly distributed on the surface of the titanium dioxide support. The size of the Co nanoparticles is about 2 nm and has good dispersibility, indicating that the synthesis method adopted has a high controllability.

[0067] Figure 8 Elemental mapping image of titanium dioxide supported HCP-Co nanoparticles prepared in Example 4, from Figure 8 It can be seen that Ti, O, and Co elements are evenly distributed throughout the particle area, and no obvious element aggregation is observed. This indicates that the Co element has been successfully loaded on the surface of the TiO2 support and is evenly distributed.

[0068] Comparative Example 1

[0069] The only difference from Example 1 is that dry ball milling is used. The specific steps are as follows:

[0070] Weigh 200 mg of HCP-Co (20 nm particle size) and 800 mg of titanium dioxide (30 nm particle size) and mix them thoroughly. Then, transfer the mixture to a ball mill, add 10 10 mm diameter zirconium oxide balls, and purge the mill with nitrogen for 10 minutes. Set the milling time to 14 hours at 800 rpm to obtain the TiO2@Co catalyst.

[0071] Figure 9 The Cs-STEM images of the TiO2@Co catalyst prepared in Comparative Example 1 at different positions and magnifications show that no small nanoparticles are supported on the support, indicating that the metal phase is not on the support surface. Figure 10 This is the elemental mapping image of the TiO2@Co catalyst prepared in Comparative Example 1, which shows that the supported HCP-Co is aggregated together in the form of large particles with a size of about 500 nm. Figure 3 and Figure 4 The results showed that it was impossible to prepare TiO2-loaded HCP-Co nanoparticles by dry ball milling.

[0072] The results of Comparative Example 1 and Example 1 show that wet ball milling (Example 1) can effectively reduce the particle size (20nm before ball milling, about 2nm after ball milling), significantly improve the uniform load of Co particles on the TiO2 carrier surface, and suppress the oxidation and agglomeration phenomenon that may occur during ball milling. In contrast, the Co particles obtained by dry ball milling (Comparative Example 1) have a larger particle size (20nm before ball milling, about 500nm after ball milling), uneven load, and are prone to agglomeration. On the one hand, this is because in dry ball milling, since there is no liquid (i.e. solvent) as a cooling medium, the heat generated during the grinding process cannot be effectively dissipated, and this high temperature can cause the particle surface to melt or soften, further promoting adhesion and aggregation between particles; especially in materials with lower hardness, particles are easily deformed due to increased temperature, causing agglomeration. On the other hand, in the dry ball milling process, since there is no liquid medium to neutralize or shield the electrostatic interaction between the particles, the particle surface may accumulate charge, and this electrostatic force promotes the attraction between the particles, causing the particles to agglomerate. The liquid medium used in wet ball milling effectively disperses and stabilizes particles, minimizing direct collisions and reducing the likelihood of agglomeration. The liquid not only acts as a cooling medium, slowing heat buildup, but also provides surface tension, preventing particles from clinging. The liquid medium used in wet ball milling improves particle stability, enhancing dispersion and uniformity while preventing agglomeration. In this state, particles tend to maintain a smaller size and are more evenly distributed.

[0073] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a supported nanoparticle catalyst by wet ball milling, comprising the following steps: The carrier, the metal phase and the solvent are wet ball-milled under the protection of an inert gas to obtain the supported nanoparticle catalyst; the supported nanoparticle catalyst comprises a carrier and metal phase nanoparticles supported on the carrier.

2. The method according to claim 1, characterized in that The carrier includes one or more of metal oxides, SiO2, molecular sieves and Si3N4.

3. The method according to claim 2, characterized in that The metal oxide includes one or more of TiO2, Al2O3, ZrO2 and MgO; the molecular sieve includes one or more of ZSM-5 molecular sieve, MCM-41 molecular sieve and SBA-15 molecular sieve.

4. The method according to claim 1, wherein The metal phase includes one or more of transition metal oxides, transition metal nitrates, transition metal acetates, noble metal elements, and transition metal elements.

5. The method according to claim 4, characterized in that The transition metal elements in the transition metal oxides, transition metal nitrates, transition metal acetates and transition metal elements independently include one or more of Fe, Co, Ni, Cu, Mn, Zn, Ti and Mo; the precious metal elements include one or more of Pt, Pd, Rh, Au and Ir.

6. The method according to any one of claims 1 to 5, characterized in that The mass ratio of the carrier to the metal phase is 5 to 20:

1.

7. The method according to claim 1, characterized in that A surfactant is also added during the wet ball milling; the mass ratio of the total mass of the carrier and the metal phase to the surfactant is 1000:1-5.

8. The method according to claim 1, characterized in that The solvent includes one or more of water, acetone and alcohol solvents.

9. The method according to claim 1, characterized in that The volume ratio of the total mass of the carrier and the metal phase to the polar solvent is 1 g: 1 to 10 mL.

10. The method according to any one of claims 1 to 5 and 7 to 9, characterized in that The wet ball milling has a rotation speed of 100 to 1500 rpm, a time of 0.5 to 48 hours, and a ball-to-material ratio of 10 to 100:1.

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