Micron-sized spherical platinum powder and its preparation method

Abstract

This application provides a micron-sized spherical platinum powder and its preparation method, belonging to the field of precious metal materials technology. The preparation method involves adding a water-soluble sugar derivative with both hydroxyl functional groups and ether bonds as a dispersant, combined with a temperature-controlled process to regulate the chemical state changes and reduction process of platinum. Under the synergistic effect of the hydroxyl and ether bonds in the dispersant, the particle size of the spherical platinum powder is controlled at the micron level, resulting in platinum powder with high sphericity, good dispersibility, and a narrow particle size distribution. This preparation method is simple, requires minimal equipment, and possesses high safety and reliability, making it suitable for mass production. This platinum powder can be used as a functional phase particle in conductive pastes for electronic components.

Description

Technical Field

[0001] This application relates to the field of precious metal materials technology, specifically to a micron-sized spherical platinum powder and its preparation method. Background Technology

[0002] Precious metal conductive pastes for electronic components are key functional materials in the modern electronics industry. Like the "neural network" of the electronic world, they are used to create precise conductive lines and electrodes on substrates such as ceramics through printing or coating, enabling circuit interconnection, signal transmission, and energy conversion. The excellent conductivity, superior oxidation resistance, and excellent corrosion resistance of precious metal pastes ensure the reliability of electronic devices in harsh environments, driving the development of electronic technology towards miniaturization, high frequency, and high reliability. As the functional phase particles in conductive pastes, the sphericity, particle size distribution, and dispersibility of platinum powder determine the performance of the conductive paste, ultimately affecting the efficiency and lifespan of electronic products.

[0003] Currently, platinum powder obtained by wet chemical methods exhibits uneven particle size distribution and a wide particle size distribution. Patent publication CN112692274A discloses a method for preparing and applying highly dispersible ultrafine platinum powder. This method involves pre-reducing platinum with a weak reducing agent to form a platinum compound with an intermediate valence state, followed by reduction with a strong reducing agent to prepare ultrafine platinum powder. Although the platinum powder obtained by this method has a narrower particle size distribution, the particle size range is 0.2–0.8 μm, and the synthesized particle size range is submicron. Furthermore, this technology requires two reduction steps, making the operation cumbersome and increasing the complexity of the platinum powder preparation process.

[0004] Patent CN117483777A discloses a method for preparing high-tap-density micron-sized spherical platinum powder. This method combines chemical reduction, ball milling, and high-temperature treatment to produce platinum powder with a narrow particle size distribution. However, the resulting platinum powder has low sphericity and a large particle size. The particle size distribution of the platinum powder affects the tap density and the performance of subsequent electronic pastes. Excessively coarse particle size hinders the formation of subsequent electronic pastes; conversely, excessively small particle size leads to poor dispersion of the stationary phase in the paste, excessive shrinkage during sintering, and the formation of defects such as pores, thus affecting device performance.

[0005] Currently, there is a lack of methods for preparing micron-sized spherical platinum powder with high dispersibility, high sphericity, and narrow particle size distribution. Summary of the Invention

[0006] In view of the technical problems existing in the background art, this application provides a micron-sized spherical platinum powder and its preparation method. The preparation method can obtain micron-sized, highly dispersible, highly spherical and uniformly distributed platinum powder, and the operation process is simple. The obtained platinum powder can be used as functional phase particles in precious metal pastes for electronic components.

[0007] In a first aspect, embodiments of this application provide a method for preparing micron-sized spherical platinum powder, the specific steps of which are as follows:

[0008] S1, dissolve the dispersant and reducing agent in water, add inorganic acid, preheat to the first temperature, and denot this as solution A;

[0009] S2, the platinum precursor is dissolved in water and preheated to a first temperature. Then, the platinum precursor solution is added dropwise to solution A using a peristaltic pump. The amount of H+ in the reaction system is controlled by adjusting the amount of inorganic acid added. + The concentration is 0.01-0.1 mol / L. After stirring and reacting at the first temperature for 10-60 min, the temperature is raised to the second temperature and stirred until a turbid solution is obtained. Stirring is then continued for 20-30 min. The turbid solution is filtered, washed with water until neutral, and dried to obtain micron-sized spherical platinum powder with a particle size between 0.8 and 1.3 μm.

[0010] In some embodiments, the dispersant is one of β-cyclodextrin, alkyl glycoside, or water-soluble cellulose ether derivatives.

[0011] In some embodiments, the first temperature is 10-45°C and the second temperature is 60-90°C.

[0012] In some embodiments, the mass ratio of the platinum precursor:dispersant:reducing agent is 1 g:(0.024-0.097) g:(0.16-1.6) g.

[0013] In some embodiments, the reducing agent is one of sodium borohydride, potassium borohydride, hydrazine hydrate, sodium bisulfite, and potassium bisulfite.

[0014] In some embodiments, the concentration of the dispersant is 0.00015~0.0006 g / ml.

[0015] In some embodiments, the concentration of the reducing agent is 0.001~0.01 g / ml.

[0016] In some embodiments, the platinum precursor is one of chloroplatinic acid, potassium chloroplatinate, and sodium chloroplatinate.

[0017] In some embodiments, the inorganic acid is one of hydrochloric acid and carbonic acid.

[0018] Secondly, embodiments of this application provide a micron-sized spherical platinum powder, which is prepared according to any of the foregoing technical solutions, and the tap density of the micron-sized spherical platinum powder is 1.3-1.4 g / cm³. 3 .

[0019] The beneficial effects of this application are:

[0020] This application provides a method for preparing micron-sized spherical platinum powder via chemical reduction. By adding a water-soluble sugar derivative possessing both hydroxyl and ether functional groups as a dispersant, and combining this with a temperature-controlled process, the chemical state changes and reduction process of platinum are controlled. Through the synergistic effect of the hydroxyl and ether bonds in the dispersant, the particle size of the spherical platinum powder is controlled at the micron level, resulting in platinum powder with high sphericity, good dispersibility, and a narrow particle size distribution.

[0021] The micron-sized spherical platinum powder preparation process and production equipment provided in this application are simple, have high safety and reliability, require low-cost reagents, and are suitable for mass production and application.

[0022] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0024] Figure 1 This is a 2500x electron microscope image of the platinum powder prepared in Example 1.

[0025] Figure 2 This is a 20,000x electron microscope image of the platinum powder prepared in Example 1.

[0026] Figure 3 This is a 2600x electron microscope image of the platinum powder prepared in Comparative Example 1.

[0027] Figure 4 The image is a 2000x electron microscope image of the platinum powder prepared for Comparative Example 2.

[0028] Figure 5 This is a 20,000x electron microscope image of the platinum powder prepared in Comparative Example 2.

[0029] Figure 6 This is a 2000x electron microscope image of the platinum powder prepared in Comparative Example 3.

[0030] Figure 7 This is an 8000x electron microscope image of the platinum powder prepared in Comparative Example 3.

[0031] Figure 8This is a 1000x electron microscope image of the platinum powder prepared in Comparative Example 4.

[0032] Figure 9 This is a 4000x electron microscope image of the platinum powder prepared in Comparative Example 4.

[0033] Figure 10 This is a 15,000x electron microscope image of the platinum powder prepared in Example 2.

[0034] Figure 11 This is a 20,000x electron microscope image of the platinum powder prepared in Example 3.

[0035] Figure 12 This is a 2000x electron microscope image of the platinum powder prepared in Comparative Example 5.

[0036] Figure 13 This is a 5000x electron microscope image of the platinum powder prepared in Comparative Example 5.

[0037] Figure 14 This is a 2000x electron microscope image of the platinum powder prepared in Comparative Example 6.

[0038] Figure 15 This is a 1000x electron microscope image of the platinum powder prepared in Comparative Example 8.

[0039] Figure 16 This is a 7000x electron microscope image of the platinum powder prepared in Comparative Example 8.

[0040] Figure 17 This is a 1000x electron microscope image of the platinum powder prepared in Comparative Example 9.

[0041] Figure 18 This is a 7000x electron microscope image of the platinum powder prepared in Comparative Example 9.

[0042] Figure 19 This is a 2000x electron microscope image of the platinum powder prepared for Comparative Example 10.

[0043] Figure 20 The image is a 7000x electron microscope image of the platinum powder prepared for Comparative Example 10.

[0044] Figure 21 This is a 1000x electron microscope image of the platinum powder prepared in Comparative Example 11.

[0045] Figure 22 This is a 7000x electron microscope image of the platinum powder prepared in Comparative Example 11.

[0046] Figure 23 This is a 2000x electron microscope image of the platinum powder prepared for Comparative Example 12.

[0047] Figure 24 This is a 7000x electron microscope image of the platinum powder prepared for Comparative Example 12. Detailed Implementation

[0048] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0050] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0051] In the description of the embodiments of this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0052] In a first aspect, embodiments of this application provide a method for preparing micron-sized spherical platinum powder, the specific steps of which are as follows:

[0053] S1, dissolve the dispersant and reducing agent in water, add inorganic acid, preheat to the first temperature, and denot this as solution A;

[0054] Among them, the inorganic acid is one of hydrochloric acid and carbonic acid.

[0055] The reducing agent is one of sodium borohydride, potassium borohydride, hydrazine hydrate, sodium bisulfite, or potassium bisulfite. The concentration of the reducing agent is 0.001~0.01 g / ml.

[0056] The dispersant is one of β-cyclodextrin, alkyl glycoside, or water-soluble cellulose ether derivatives. The concentration of the dispersant is 0.00015~0.0006 g / ml.

[0057] S2, the platinum precursor is dissolved in water and preheated to a first temperature. Then, the platinum precursor solution is added dropwise to solution A using a peristaltic pump. The amount of H+ in the reaction system is controlled by adjusting the amount of inorganic acid added. + The concentration is 0.01-0.1 mol / L. After stirring and reacting at the first temperature for 10-60 min, the temperature is raised to the second temperature and stirred until a turbid solution is obtained. Stirring is then continued for another 20-30 min. The turbid solution is filtered, washed with water until neutral, and dried to obtain micron-sized spherical platinum powder with a particle size of approximately 0.8-1.3 μm.

[0058] The first temperature is 10-45℃, and the second temperature is 60-90℃.

[0059] The mass ratio of platinum precursor: dispersant: reducing agent is 1 g: (0.024-0.097) g: (0.16-1.6) g.

[0060] The platinum precursor is one of chloroplatinic acid, potassium chloroplatinate, or sodium chloroplatinate.

[0061] The drying temperature is 10-40℃, and the drying time is 6-24 h.

[0062] In this embodiment, by adding a water-soluble sugar derivative with both hydroxyl functional groups and ether bonds as a dispersant, and combining it with a temperature-controlled program, the chemical state changes and reduction process of platinum are controlled. Under the synergistic effect of the hydroxyl and ether bonds of the dispersant, the particle size of spherical platinum powder is controlled at the micron level, and the prepared platinum powder has high sphericity, good dispersibility, and narrow particle size distribution.

[0063] Secondly, this application also provides a micron-sized spherical platinum powder, which is prepared by the preparation method described in any of the foregoing technical solutions, and the tap density of the micron-sized spherical platinum powder is 1.3-1.4 g / cm³. 3 .

[0064] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0065] Example 1

[0066] Example 1 provides a method for preparing micron-sized spherical platinum powder, comprising the following steps:

[0067] S1, prepare an aqueous solution of hydrazine hydrate and cellulose methyl ether, and add hydrochloric acid. The concentrations of reducing agent and dispersant are 0.003 g / ml and 0.00023 g / ml, respectively. Preheat to 40℃ and denote as liquid A.

[0068] S2, prepare a 0.025 g / ml chloroplatinic acid solution, stir thoroughly, and preheat to 40°C, denoted as liquid B. Add liquid B to liquid A using a peristaltic pump. Adjust the pH of the reaction system to 1.5 (corresponding to a hydrogen ion concentration of 0.0316 mol / L) by controlling the amount of hydrochloric acid added. After stirring for 30 min, raise the temperature of the reaction system to 60°C and continue stirring until a gray-black precipitate appears. Continue stirring for another 20 min, then filter, wash with deionized water until neutral, and then dry at 30°C to obtain platinum powder. In this system, the mass ratio of chloroplatinic acid: cellulose methyl ether: hydrazine hydrate is 1:0.037:0.486.

[0069] like Figure 1-2 As shown, electron microscopy tests revealed that the prepared platinum powder was micron-sized spherical platinum powder with a particle size range of approximately 0.9–1.3 μm. The platinum powder had a regular shape, high sphericity, uniform distribution, smooth surface, and no obvious defects were found.

[0070] The tap density data of the platinum powder prepared in Example 1 are shown in Table 1.

[0071] Comparative Example 1

[0072] The difference between Comparative Example 1 and Example 1 is that no dispersant was added. The other contents are roughly the same as those in Example 1, and will not be repeated here.

[0073] Electron micrograph of the platinum powder prepared in Comparative Example 1 is shown below. Figure 3 As shown, the platinum powder exhibits extremely poor sphericity and dispersibility.

[0074] Comparative Example 2

[0075] The difference between Comparative Example 2 and Example 1 is that the dispersant cellulose methyl ether is replaced with polyvinylpyrrolidone. The other contents are roughly the same as those in Example 1, and will not be repeated here.

[0076] Electron micrograph of the platinum powder prepared in Comparative Example 2 is shown below. Figure 4-5 As shown, the obtained platinum powder has poor sphericity and a small particle size, falling into the submicron range.

[0077] Comparative Example 3

[0078] The difference between Comparative Example 3 and Example 1 is that the dispersant cellulose methyl ether is replaced with polyethylene glycol. The other contents are roughly the same as those in Example 1, and will not be repeated here.

[0079] Electron micrograph of the platinum powder prepared in Comparative Example 3 is shown below. Figure 6-7 As shown, the prepared platinum powder has poor dispersibility.

[0080] Comparative Example 4

[0081] The difference between Comparative Example 4 and Example 1 is that the dispersant cellulose methyl ether is replaced with polyvinyl alcohol. The other contents are roughly the same as those in Example 1, and will not be repeated here.

[0082] Electron micrograph of the platinum powder prepared in Comparative Example 4 is shown below. Figure 8-9 As shown, the prepared platinum powder has poor dispersibility.

[0083] Example 2-3

[0084] The difference between Examples 2-3 and Example 1 is that the dispersant cellulose methyl ether is replaced with β-cyclodextrin and alkyl glycoside, respectively. The other contents are roughly the same as those in Example 1, and will not be repeated here.

[0085] The process parameters of Examples 1-3 and Comparative Examples 1-4 are summarized in Table 1.

[0086] Table 1

[0087]

[0088] Experiments show that the platinum powder prepared in Examples 2-3 has a regular shape, high sphericity, uniform distribution, smooth surface, and a particle size range in the micrometer range. Figure 10-11 As shown.

[0089] As shown in the table above, in Comparative Example 1, the platinum powder obtained had extremely poor sphericity and dispersibility due to the absence of a dispersant, demonstrating the structure-guiding and dispersing effects of the dispersant.

[0090] In Comparative Example 2, using polyvinylpyrrolidone as a dispersant resulted in poor sphericity and small particle size of the platinum powder. Comparative Examples 3 and 4, using polyethylene glycol and polyvinyl alcohol as dispersants respectively, also yielded platinum powders with poor dispersibility. The reasons may be as follows: polyvinylpyrrolidone does not contain hydroxyl groups; polyethylene glycol only contains hydroxyl groups at both ends, resulting in a very low number of hydroxyl groups; polyvinyl alcohol does not contain ether bonds and only contains hydroxyl groups at both ends; neither polyvinylpyrrolidone nor polyvinyl alcohol possesses both hydroxyl and ether bond groups; and polyethylene glycol only contains hydroxyl groups at both ends, resulting in a low number of hydroxyl groups per molecule. Therefore, by comparing the platinum powders obtained in Example 1 and Comparative Examples 2-4, it can be concluded that in this system, only by using an organic dispersant with a large number of ether bonds and hydroxyl groups can its spherical structure guiding and dispersant functions be fully utilized to achieve the preparation of micron-sized spherical platinum powder.

[0091] Comparative Example 5

[0092] The difference between Comparative Example 5 and Example 1 is that the reaction was carried out at a constant temperature of 60°C instead of first at 40°C and then at 60°C. The rest is roughly the same as Example 1 and will not be repeated here.

[0093] Electron micrograph of the platinum powder prepared in Comparative Example 5 is shown below. Figure 12-13 As shown, the prepared platinum powder has poor dispersibility, contains a large amount of submicron-sized platinum powder, and also contains some aggregated flake-like platinum powder.

[0094] Comparative Example 6

[0095] The difference between Comparative Example 6 and Example 1 is that the reaction at 40°C followed by a reaction at 60°C is replaced with the reaction at 60°C followed by a reaction at 40°C. The specific steps are as follows:

[0096] Prepare an aqueous solution of hydrazine hydrate and cellulose methyl ether, and add hydrochloric acid. The concentrations of reducing agent and dispersant are 0.003 g / ml and 0.00023 g / ml, respectively. Preheat to 60°C, and denote this as liquid A. Prepare a 0.025 g / ml chloroplatinic acid solution, stir evenly, and preheat to 60°C, denote this as liquid B. Add liquid B to liquid A using a peristaltic pump. Adjust the pH of the reaction system to 1.5 by controlling the amount of hydrochloric acid added. Stir until a gray-black precipitate appears, then lower the temperature of the reaction system to 40°C, continue stirring for 20 min, filter, wash with deionized water until neutral, and then dry at 30°C to obtain platinum powder.

[0097] Electron micrograph of the platinum powder prepared in Comparative Example 6 is shown below. Figure 14 As shown, the prepared platinum powder has poor dispersibility, contains a large amount of submicron-sized platinum powder, and also contains some aggregated flake-like platinum powder.

[0098] Comparative Example 7

[0099] The difference between Comparative Example 7 and Example 1 is that the reaction, which proceeded from 40°C to 60°C, was replaced with a constant temperature reaction at 40°C. The specific steps are as follows:

[0100] An aqueous solution of hydrazine hydrate and cellulose methyl ether was prepared, and hydrochloric acid was added. The concentrations of reducing agent and dispersant were 0.003 g / ml and 0.00023 g / ml, respectively. The solution was preheated to 40°C and denoted as liquid A. A 0.025 g / ml chloroplatinic acid solution was prepared, stirred thoroughly, and preheated to 40°C; this solution was denoted as liquid B. Liquid B was added to liquid A using a peristaltic pump. The pH of the reaction system was adjusted to 1.5 by controlling the amount of hydrochloric acid added. After stirring, no precipitation occurred. This indicates that chloroplatinic acid cannot be reduced to platinum at 40°C.

[0101] Examples 4-5 and Comparative Examples 8-9

[0102] The difference between Examples 4-5 and Comparative Examples 8-9 and Example 1 is that the hydrogen ion concentration in the reaction system is different, as shown in Table 2; the other contents are roughly the same as those in Example 1, and will not be repeated here.

[0103] Table 2

[0104]

[0105] Experiments show that when the hydrogen ion concentration in the reaction system is higher than 0.1 mol / L (Comparative Example 8), the prepared platinum powder has poor dispersibility and contains large submicron-sized spherical platinum powder and aggregated flake-like platinum powder, such as... Figure 15-16 As shown.

[0106] When the hydrogen ion concentration in the reaction system is below 0.01 mol / L (Comparative Example 9), the prepared platinum powder exhibits poor dispersibility and sphericity, with some platinum powder having an uneven surface and containing aggregated, flaky platinum powder. Figure 17-18 As shown.

[0107] Comparative Example 10

[0108] Comparative Example 10 used a two-step method with hydrazine carbonate to prepare platinum powder. The specific steps are as follows:

[0109] Prepare an aqueous solution of hydrazine hydrate and cellulose methyl ether, and add hydrochloric acid. The concentrations of reducing agent and dispersant are 0.003 g / ml and 0.00023 g / ml, respectively. Preheat to 40°C and denote this solution as liquid A.

[0110] Prepare a 0.025 g / ml chloroplatinic acid solution, add 0.058 g hydrazine carbonate, stir well, and preheat to 40°C. This solution is designated as liquid B. Add liquid B to liquid A using a peristaltic pump. After stirring for 30 min, raise the temperature of the reaction system to 60°C. Adjust the pH of the reaction system to 0.88 by controlling the amount of hydrochloric acid added. Continue stirring until a gray-black precipitate appears. Continue stirring for another 20 min, filter, wash with deionized water until neutral, and then dry at 30°C to obtain platinum powder.

[0111] like Figures 19-20 As shown, the obtained platinum powder has poor sphericity and dispersibility, obvious surface defects, and obvious aggregated platinum powder.

[0112] Examples 6-7 and Comparative Examples 11-12

[0113] The difference from Example 1 is that the concentration of the dispersant was changed, as shown in Table 3; the other contents are roughly the same as in Example 1, and will not be repeated here.

[0114] Table 3

[0115]

[0116] Experiments show that when the concentration of the dispersant is below 0.00015 g / ml (Comparative Example 11), the prepared platinum powder has poor dispersibility, obvious surface defects, and a large number of aggregated flake-like platinum powder particles, such as... Figure 21-22 As shown.

[0117] When the concentration of the dispersant is higher than 0.0006 g / ml (Comparative Example 12), the prepared platinum powder contains a large number of submicron-sized particles, exhibits poor dispersibility, shows obvious surface defects, and contains clearly aggregated platinum powder, such as... Figure 23-24 As shown.

[0118] 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 micron-sized spherical platinum powder, characterized in that, Includes the following steps: S1, dissolve the dispersant and reducing agent in water, add an inorganic acid, and preheat to a first temperature, denoted as solution A; the dispersant is one of β-cyclodextrin, alkyl glycoside, and water-soluble cellulose ether derivatives; S2, the platinum precursor is dissolved in water and preheated to a first temperature. Then, the platinum precursor solution is added dropwise to solution A using a peristaltic pump. The amount of H+ in the reaction system is controlled by adjusting the amount of inorganic acid added. + The concentration is 0.01-0.1 mol / L. After stirring and reacting at the first temperature for 10-60 min, the temperature is raised to the second temperature, and the reaction is stirred at the second temperature until a turbid solution is obtained. Stirring is then continued for another 20-30 min. The turbid solution is filtered, washed with water until neutral, and dried to obtain micron-sized spherical platinum powder with a particle size between 0.8 and 1.3 μm. The first temperature is 10-45℃, and the second temperature is 60-90℃. The mass ratio of platinum precursor: dispersant: reducing agent is 1 g: (0.024-0.097) g: (0.16-1.6) g.

2. The method for preparing micron-sized spherical platinum powder according to claim 1, characterized in that, The reducing agent is one of sodium borohydride, potassium borohydride, hydrazine hydrate, sodium bisulfite, and potassium bisulfite.

3. The method for preparing micron-sized spherical platinum powder according to claim 1, characterized in that, The concentration of the dispersant is 0.00015~0.0006 g / ml.

4. The method for preparing micron-sized spherical platinum powder according to claim 1, characterized in that, The concentration of the reducing agent is 0.001~0.01 g / ml.

5. The method for preparing micron-sized spherical platinum powder according to claim 1, characterized in that, The platinum precursor is one of chloroplatinic acid, potassium chloroplatinate, or sodium chloroplatinate.

6. The method for preparing micron-sized spherical platinum powder according to claim 1, characterized in that, The inorganic acid is either hydrochloric acid or carbonic acid.

7. A micron-sized spherical platinum powder, characterized in that, The micron-sized spherical platinum powder The micron-sized spherical platinum powder is prepared by the method according to any one of claims 1-6, wherein the tap density of the micron-sized spherical platinum powder is 1.3-1.4 g / cm³. 3 .

Images