A method for preparing a platinum black catalyst with controllable particle size by using an amidine ligand

Abstract

The application belongs to the technical field of noble metal nanometer material preparation, and particularly relates to a method for preparing a platinum black catalyst with controllable particle size by using an amidine ligand, which comprises the following steps: dispersing a platinum salt in a mixed solvent of deionized water and a monohydric alcohol to form a slurry with a platinum mass concentration of 0.24-2 wt%; adding an aqueous solution of an amidine ligand to the slurry; adjusting the pH of the solution to 9-10; under stirring, heating the reaction solution in an oil bath, increasing the temperature to 80-110 DEG C at a speed of 1-5 DEG C / min, and reducing for 1-6 hours; centrifugally separating and washing the product, and drying; heating the obtained black powder to 100-250 DEG C at a speed of 2-5 DEG C / min under an inert atmosphere, and heat treating for 30-180 min to obtain a platinum black catalyst. The application prepares a platinum black catalyst with high purity and controllable particle size by using a water-alcohol-alkaline composite reduction system and adding an amidine substance under mild conditions.

Description

Technical Field

[0001] This invention belongs to the field of precious metal nanomaterial preparation technology, specifically relating to a method for preparing a platinum black catalyst with controllable particle size using amidine ligands. Background Technology

[0002] In fields such as energy catalysis, electrochemical sensing, and environmental remediation, platinum black catalysts play an irreplaceable role due to their excellent catalytic activity, high specific surface area, and good chemical stability. Especially in proton exchange membrane fuel cells, platinum black, as a key electrode catalyst, can significantly improve the efficiency of hydrogen oxidation and oxygen reduction reactions, driving the development of clean energy technologies. However, platinum resources are scarce and expensive; therefore, how to efficiently prepare platinum black catalysts while reducing their dosage and improving performance has become a key research topic.

[0003] Currently, the main methods for preparing platinum black catalysts include chemical reduction, electrochemical deposition, physical vapor deposition, and biosynthesis. Chemical reduction uses reducing agents (such as sodium citrate or ethylene glycol) to reduce platinum salts into nanoparticles. This method is simple to operate, low in cost, and can achieve large-scale preparation, but it is prone to particle agglomeration, leading to a reduction in active sites. Electrochemical deposition directly generates platinum black on the substrate surface by controlling the electrode potential and electrolyte composition. Its advantage lies in the precise control of film thickness and particle size, making it suitable for customized electrode preparation. However, this method requires sophisticated equipment, and the deposition process is easily affected by electrolyte composition and temperature fluctuations. Physical vapor deposition uses high-temperature evaporation or sputtering to deposit platinum atoms, enabling the preparation of high-purity, uniform platinum black films. However, the equipment is expensive and energy-intensive, limiting its industrial application. Biosynthesis utilizes the reduction action of microorganisms or biomolecules to prepare platinum black. It is environmentally friendly and has mild reaction conditions, but the synthesis efficiency is low, and it is difficult to precisely control particle morphology and size. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a method for preparing platinum black catalysts with controllable particle size using amidine ligands. Addressing the problems of high reaction temperatures (typically >160℃), difficulty in completely removing residual organic ligands (such as PVP stabilizers) from the product, rapid reduction rates, and wide particle size distribution (±15nm) associated with traditional polyol methods, this invention prepares high-purity, particle-controllable platinum black and high-load platinum-based catalysts under mild conditions through a water-alcohol-alkaline composite reduction system, by adding amidine substances. This improves the purity of the catalyst product and achieves particle size control.

[0005] To achieve the above technical objectives, the technical solution adopted in the embodiments of the present invention is as follows: A method for preparing a platinum black catalyst with controllable particle size using amidine ligands includes the following steps: (1) Preparation of platinum-containing precursor slurry: Platinum salt is dispersed in a mixed solvent of deionized water and monohydric alcohol to form a slurry with a platinum mass concentration of 0.24wt%-2wt%; (2) Introduction of amidine ligands: Add an aqueous solution of amidine ligands with the general formula RC(=NH)-NH2 to the slurry of step (1); (3) Reduction reaction: Add alkaline substances to the mixed solution in step (2) to adjust the pH to 9-10. Under stirring conditions, place the pH-adjusted reaction solution in an oil bath and heat it to 80-110℃ at a rate of 1-5℃ / min. The reduction reaction lasts for 1-6 hours. After centrifugation, the product is washed with ethanol and water alternately and then dried. (4) Post-treatment: The black powder obtained in step (3) is heat-treated at 100-250℃ for 30-180 minutes under an inert atmosphere by heating at 2-5℃ / min to obtain platinum black catalyst.

[0006] Further, in step (1), the platinum salt includes one or more combinations of ammonium chloroplatinate, chloroplatinic acid, and tetraammineplatinum nitrate; The mass ratio of platinum to water in the platinum salt is 1:50-1:300; The monohydric alcohol is a monohydric alcohol with 1-4 carbon atoms, including one or more combinations of n-propanol, isopropanol and ethanol, and the mass ratio of platinum to monohydric alcohol in the platinum salt is 1:40-1:100.

[0007] Further, in step (2), the amidine ligand is one or more of formamidine hydrochloride, benzamide, acetylamidinium and N,N-dimethylformamidine, and the molar ratio of platinum to amidine ligand in the platinum salt is 1:1 to 1:5.

[0008] Furthermore, in step (3), the alkaline substance includes one or more combinations of sodium hydroxide, potassium hydroxide, and sodium carbonate; The drying temperature is 40-60℃, and the drying time is 8-24 h.

[0009] The beneficial effects of the technical solution provided by the embodiments of the present invention are as follows: 1. The preparation method of the present invention has mild reaction conditions, with a reaction temperature below 110°C, and does not require microwaves or high-pressure reactors; the production cycle is short, the reaction conditions are simple, and there is the possibility of large-scale production.

[0010] 2. Introducing a dual-action mechanism of amidine ligands: amidine ligands (RC(=NH)-NH2) have electron-rich nitrogen atoms that can form strong coordination with platinum ions.

[0011] The reduction process / nucleation growth can be dynamically controlled: amidine and Pt4+ / Pt 2+ It forms thermodynamically stable complexes, stabilizes Pt ions / intermediates, prevents premature and uncontrollable reduction and aggregation, prevents aggregation, and inhibits Ostwald ripening; Simultaneously, it improves the surface cleanliness and synergistic catalytic effect of the catalyst: the decomposition temperature is low (≤250℃), there is no carbon residue after calcination, avoiding the metal contamination of traditional polymer stabilizers (such as PVP), and the small amount of residual nitrogen-containing species may change the electronic structure of the platinum surface, improving ORR activity or stability.

[0012] 3. Mild heat treatment conditions: The post-treatment temperature is low (100-250℃), which is designed to remove organic matter without causing severe sintering of platinum particles, and helps to maintain activity and dispersibility.

[0013] The performance of platinum black is significantly improved by a three-pronged process of directional stabilization with amidine ligands, mild gradient reduction, and low-temperature post-treatment.

[0014] Amidine ligands anchor platinum crystal nuclei ↓ Coordination protection → Inhibition of Ostwald ripening → Small particle size ↓ Gradient reduction → Controlled nucleation growth → High dispersion ↓ Low-temperature annealing → ligand removal + structural stabilization → high activity Attached Figure Description

[0015] Figure 1 This is a flowchart of the process for preparing a platinum black catalyst with controllable particle size using amidine ligands, as described in this invention.

[0016] Figure 2 These are the XRD patterns of the catalysts prepared in Examples 1 and 3 and Comparative Examples 1 and 2 of this invention.

[0017] Figure 3a These are the half-cell cyclic voltammetry scan curves of Embodiment 2 and Comparative Examples 1 and 3 of the present invention.

[0018] Figure 3b These are the half-cell current-voltage scan curves of Embodiment 2 and Comparative Examples 1 and 3 of the present invention.

[0019] Figure 4 This describes the full-cell performance of Embodiment 3 and Comparative Examples 1 and 2 of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0021] Example 1 A method for preparing a platinum black catalyst with controllable particle size using amidine ligands includes the following steps: (1) Preparation of platinum-containing precursor slurry: Weigh 1.0g ammonium chloroplatinate ((NH4)2PtCl6), add it to a mixed solvent consisting of 100g deionized water and 40g ethanol, stir for 30 min to form a uniform slurry; (2) Introduction of amidones: Weigh 0.36g of formamidine hydrochloride, dissolve it in 20g of deionized water, slowly add the solution to the slurry in step (1), and continue stirring for 30 min; (3) Reduction reaction: Add 1M sodium hydroxide aqueous solution to the mixed solution in step (2) to adjust the pH to 9.5, transfer the slurry to an oil bath, stir and heat, with the temperature program as follows: from 20℃ in increments of 2℃·min -1 The temperature is increased to 60℃ at a heating rate and held for 30 minutes; then the temperature is increased from 60℃ at a rate of 1℃·min. -1 The temperature was increased to 90℃ and held for 2 hours. After cooling, the reaction solution was centrifuged and washed three times alternately with ethanol and deionized water. The precipitate was dried in a 50℃ oven for 12 hours to obtain a black powder. (4) Post-processing: The black powder obtained after drying in step (3) is loaded into a quartz boat, placed in a tube furnace, and purged with high-purity argon gas (100 mL / min) for 30 minutes. Under an argon atmosphere, the mixture is heated at 3℃·min. -1 The temperature was increased to 200℃, held for 60 min, and then naturally cooled to room temperature to obtain the platinum black catalyst.

[0022] Example 2 A method for preparing a platinum black catalyst with controllable particle size using amidine ligands includes the following steps: (1) Preparation of platinum-containing precursor slurry: Weigh 2.0g of tetraammineplatinum nitrate (Pt(NH3)4(NO3)2) and add it to a mixed solvent consisting of 52.5g of deionized water and 42g of isopropanol. Stir for 30 minutes to form a uniform slurry. (2) Introduction of amidines: Weigh 0.5 g of acetylamidin hydrochloride, dissolve it in 15 g of deionized water, add the resulting solution to the slurry in step (1), and stir for 30 minutes; (3) Reduction reaction: Add 1M potassium hydroxide aqueous solution to the mixed solution in step (2) to adjust the pH to 10, transfer the slurry to an oil bath, stir and heat, and the temperature rise program is: from 20℃ in increments of 2℃·min -1The temperature was increased to 110℃ and held for 3 hours. After the reaction solution was cooled, it was centrifuged and washed three times alternately with ethanol and deionized water. The precipitate was dried in a 50℃ oven for 12 hours to obtain a black powder. (4) Post-processing: The black powder obtained after drying in step (3) is loaded into a quartz boat, placed in a tube furnace, and purged with high-purity argon gas (100 mL / min) for 30 minutes. Under the argon atmosphere, the mixture is heated at 5℃·min. -1 The temperature was increased to 100℃, held for 60 min, and then naturally cooled to room temperature to obtain the platinum black catalyst.

[0023] Example 3 A method for preparing a platinum black catalyst with controllable particle size using amidine ligands includes the following steps: (1) Preparation of platinum-containing precursor slurry: Weigh 0.5g of chloroplatinic acid (H2PtCl6·6H2O, containing 37.5% Pt, i.e., 0.1875g of Pt), add it to a mixed solvent consisting of 56.25g of deionized water, 7g of ethanol and 7g of n-propanol, stir for 30 minutes to form a uniform slurry; (2) Introduction of amidines: Weigh 0.570g of N,N-dimethylformamidin acetate and dissolve it in 25g of deionized water to prepare a solution. Add the above solution to the slurry in step (1) and stir for 30 minutes. (3) Reduction reaction: Add 1M sodium carbonate aqueous solution to the mixed solution in step (2) to adjust the pH to 9.0, transfer the slurry to an oil bath, stir and heat, with the temperature program as follows: from 20℃ in increments of 3℃·min -1 The temperature is increased to 50℃ at a heating rate and held for 20 min; then the temperature is increased from 50℃ at a rate of 1℃·min. -1 The temperature was increased to 80℃ and held for 5 hours. After the reaction solution was cooled, it was centrifuged and washed three times alternately with ethanol and deionized water. The precipitate was dried in an oven at 40℃ for 24 hours to obtain a black powder. (4) Post-treatment: The black powder obtained after drying in step (3) is loaded into a quartz boat, placed in a tube furnace, and purged with high-purity nitrogen (100 mL / min) for 30 minutes. Under a nitrogen atmosphere, the mixture is heated at 5 °C / min. -1 The temperature was increased to 200℃, held for 60 minutes, and then naturally cooled to room temperature to obtain the platinum black catalyst.

[0024] Comparative Example 1 A method for preparing a platinum black catalyst includes the following steps: (1) Preparation of platinum-containing precursor slurry: Weigh 1.0g ammonium chloroplatinate ((NH4)2PtCl6), add it to a mixed solvent consisting of 100g deionized water and 40g ethanol, stir for 30 min to form a uniform slurry; (2) Reduction reaction: Add 1M sodium hydroxide aqueous solution to the mixed solution in step (1) to adjust the pH to 9.5. Transfer the slurry to an oil bath, stir and heat. The temperature rise program is: from 20℃ in increments of 2℃·min. -1 The temperature is increased to 60℃ at a heating rate and held for 30 minutes; then the temperature is increased from 60℃ at a rate of 1℃·min. -1 The temperature was increased to 90℃ and held for 2 hours. After cooling, the reaction solution was centrifuged and washed three times alternately with ethanol and deionized water. The precipitate was dried in a 50℃ oven for 12 hours to obtain a black powder. (3) Post-processing: The black powder obtained after drying in step (2) is loaded into a quartz boat, placed in a tube furnace, and purged with high-purity argon gas (100 mL / min) for 30 minutes. Under an argon atmosphere, the mixture is heated at 3℃·min. -1 The temperature was increased to 200℃, held for 60 min, and then naturally cooled to room temperature to obtain the platinum black catalyst.

[0025] Comparative Example 2 A method for preparing a platinum black catalyst includes the following steps: (1) Preparation of platinum-containing precursor slurry: Weigh 1.0g ammonium chloroplatinate ((NH4)2PtCl6), add it to a mixed solvent consisting of 100g deionized water and 40g ethanol, stir for 30 min to form a uniform slurry; (2) Use PVP as a protective agent: Weigh 1.2 g PVP (K30), dissolve it in 20 g deionized water, slowly add the solution to the slurry in step (1), and continue stirring for 30 min; (3) Reduction reaction: Add 1M potassium hydroxide aqueous solution to the mixed solution in step (2) to adjust the pH to 9.5, transfer the slurry to an oil bath, stir and heat, and the temperature program is: from 20℃ in increments of 2 °C·min. -1 The temperature is increased to 60℃ at a heating rate and held for 30 minutes; then the temperature is increased from 60℃ at a rate of 1℃·min. -1 The temperature was increased to 90℃ and held for 2 hours. After the reaction solution was cooled, it was centrifuged and washed three times alternately with ethanol and deionized water. The precipitate was placed in a 50℃ oven and dried for 12 hours to obtain a black powder. (4) Post-processing: The black powder obtained after drying in step (3) is loaded into a quartz boat, placed in a tube furnace, and purged with high-purity argon gas (100 mL / min) for 30 minutes. Under the argon atmosphere, the mixture is heated at 5℃·min. -1 The temperature was increased to 400℃, held for 60 min, and then naturally cooled to room temperature to obtain the platinum black catalyst.

[0026] Comparative Example 3 A method for preparing a platinum black catalyst includes the following steps: (1) Preparation of platinum-containing precursor slurry: Weigh 2.0g of tetraammineplatinum nitrate (Pt(NH3)4(NO3)2) and add it to a mixed solvent consisting of 52.5g of deionized water and 30g of isopropanol. Stir for 30 minutes to form a uniform slurry.

[0027] (2) Introduction of amidines: Weigh 0.5g of acetylamidin hydrochloride, dissolve it in 15g of deionized water, add the solution to the slurry in step (1), and stir for 30 minutes; (3) Reduction reaction: Add 1M sodium hydroxide aqueous solution to the mixed solution in step (2) and adjust the pH to 10. Transfer the slurry to an oil bath, stir and heat. The temperature program is: from 20℃ in increments of 2℃·min. -1 The temperature was increased to 110℃ and held for 3 hours. After the reaction solution was cooled, it was centrifuged and washed three times alternately with ethanol and deionized water. The precipitate was dried in a 50℃ oven for 12 hours to obtain a black powder. (4) Post-processing: The black powder obtained after drying in step (3) is loaded into a quartz boat, placed in a tube furnace, and purged with high-purity argon gas (100 mL / min) for 30 minutes. Under the argon atmosphere, the mixture is heated at 5℃·min. -1 The temperature was increased to 100℃, held for 60 min, and then naturally cooled to room temperature to obtain the platinum black catalyst.

[0028] Comparative Example 4 A method for preparing a platinum black catalyst includes the following steps: (1) Preparation of platinum-containing precursor slurry: Weigh 0.5g of chloroplatinic acid (H2PtCl6·6H2O, containing 37.5% Pt, i.e. Pt0.1875g), add it to a mixed solvent consisting of 56.25g deionized water, 7g ethanol and 7g n-propanol, stir for 30 minutes to form a uniform slurry; (2) Introduction of amidines: Weigh 0.570g of N,N-dimethylformamidin acetate and dissolve it in 25g of deionized water to prepare a solution. Add the above solution to the slurry in step (1) and stir for 30 minutes. (3) Reduction reaction: Add 1M sodium carbonate aqueous solution to the mixed solution in step (2) to adjust the pH to 8, transfer the slurry to an oil bath, stir and heat, and the temperature program is: from 20℃ in increments of 3℃·min. -1 The temperature is increased to 50℃ at a heating rate and held for 20 min; then the temperature is increased from 50℃ at a rate of 1℃·min. -1The temperature was increased to 80℃ and held for 5 hours. After the reaction solution was cooled, it was centrifuged and washed three times alternately with ethanol and deionized water. The precipitate was dried in an oven at 40℃ for 24 hours to obtain a black powder. (4) Post-treatment: The black powder obtained after drying in step (3) is loaded into a quartz boat, placed in a tube furnace, and purged with high-purity nitrogen (100 mL / min) for 30 minutes. Under a nitrogen atmosphere, the mixture is heated at 5 °C / min. -1 The temperature was increased to 200℃, held for 60 minutes, and then naturally cooled to room temperature to obtain the platinum black catalyst.

[0029] The platinum black catalysts prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to half-cell performance testing, specifically including the following steps: 5 mg of the prepared platinum black catalyst was taken and added to 3.33 mL of pure water, 1.65 mL of isopropanol, and 50 μL of a 5% (w / w) Nafion (D520) membrane solution. The solution was dispersed into a uniformly dispersed ink using a cell disruptor in a cold (ice) water bath for 30 min at 30% power. 9.5 μL of the slurry was dropped onto a surface with a geometric area of ​​0.19625 cm². 2 A uniform thin film was formed on the working electrode of a rotating disk electrode (RDE) under infrared lamp conditions or by natural drying. A three-electrode test was performed in a 0.1 M perchloric acid solution oxygen reduction (ORR) test system. Before the test, N2 and O2 were introduced into the 0.1 M perchloric acid solution to saturate it. IR compensation was performed with a compensation resistor of 80% of the measured system resistance. The rotating disk electrode was turned on at 1600 rpm. The ORR test scan potential range was 0.2–1.2 V vs. RHE. LSV forward and reverse scan data were measured and averaged. The test results are shown in Table 1.

[0030] Fuel Cell Single Cell Fabrication: The prepared catalyst is prepared into a slurry and coated onto one side of the proton exchange membrane as the cathode layer. 200 mg of the composite-supported catalyst prepared above is accurately weighed; 20 mL of pure water, 15 mL of isopropanol, and 1.5 mL of perfluorosulfonic acid resin solution are measured and added to the catalyst. The mixture is then pulverized for 30 min to form a uniform catalyst ink. This ink is uniformly coated onto the cut proton exchange membrane and designated as the cathode. Similarly, 40% of the platinum-carbon catalyst is weighed and coated onto the other side of the membrane, designated as the anode, forming the CCM. The gas diffusion layer uses an SGL 28BC model GDL. After the battery is assembled and the gas pipeline is connected, a gas tightness test is performed. Once the gas tightness test is passed, a single-cell test is conducted.

[0031] Single cell test conditions: Single cell area 20cm² 2The stoichiometric ratio of anode to cathode is 1.5:2.5, the anode dew point is set at 64℃, the cathode dew point is set at 64℃, the anode feed pressure is 1.1 bar, the cathode feed pressure is 1.0 bar, and the battery test temperature is 80℃.

[0032] Table 1 shows the half-cell performance data of Example 2 and Comparative Examples 1 and 3 of the present invention. , Figure 1 The following is an experimental flowchart of the present invention, in which the introduction of amidine ligands, pH adjustment, and reduction reaction are the key experimental steps of this patent.

[0033] Figure 2 The XRD patterns of the catalysts prepared in Examples 1 and 3 and Comparative Examples 1 and 2 of this invention are shown. As can be seen from Examples 1 and 3 and Comparative Example 1, the introduction of amidine ligands can successfully regulate and reduce the particle size distribution of the product, with the particle size controlled within 5 nm. As can be seen from Examples 1 and Comparative Example 2, the catalysts prepared by introducing amidine ligands have better performance and more controllable particle size than the catalysts prepared by traditional PVP as a stabilizer. Furthermore, traditional PVP as a stabilizer requires a higher post-treatment temperature, while the post-treatment temperature of this invention has an optimal value. It is difficult to achieve the beneficial effects if the temperature is lower or higher than the protection range of this application.

[0034] Figure 3 shows the half-cell performance of Embodiment 2 and Comparative Examples 1 and 3 of the present invention, and Table 1 is a summary of the half-cell data; combined with Figure 3a and Figure 3b As can be seen from the comparison between Example 2 and Comparative Example 1, the introduction of amidine ligands improves the half-cell performance of the catalyst; as can be seen from the comparison between Example 2 and Comparative Example 3, the proportion range of the reactants in this invention has certain optimal values, and the performance is good within the scope of the claims of the invention.

[0035] Figure 4 The comparison of the full-cell performance of Example 1 with Comparative Examples 1 and 2 shows that the introduction of amidine-like substances increases the performance of the full-cell, and the full-cell performance is better than that of catalysts prepared with traditional PVP as stabilizers. The comparison of the full-cell performance of Example 3 with Comparative Example 4 shows that the pH range of the reactants of the present invention has a certain optimal value, and the performance is better within the scope of the claims of the invention, and its full-cell performance is better.

[0036] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing a platinum black catalyst with controllable particle size using amidine ligand-assisted synthesis, characterized in that, Includes the following steps: (1) Preparation of platinum-containing precursor slurry: Platinum salt is dispersed in a mixed solvent of deionized water and monohydric alcohol to form a slurry with a platinum mass concentration of 0.24wt%-2wt%; (2) Introduction of amidine ligands: Add an aqueous solution of amidine ligands with the general formula RC(=NH)-NH2 to the slurry of step (1); (3) Reduction reaction: Add alkaline substances to the mixed solution in step (2) to adjust the pH to 9-10. Under stirring conditions, place the pH-adjusted reaction solution in an oil bath and heat it to 80-110℃ at a rate of 1-5℃ / min. The reduction reaction lasts for 1-6 hours. After centrifugation, the product is washed with ethanol and water alternately and then dried. (4) Post-treatment: The black powder obtained in step (3) is heat-treated at 100-250℃ for 30-180 minutes under an inert atmosphere by heating at 2-5℃ / min to obtain platinum black catalyst; In step (2), the amidine ligand is one or more of formamidine hydrochloride, benzamide, acetylamidinium and N,N-dimethylformamidine, and the molar ratio of platinum to amidine ligand in the platinum salt is 1:1 to 1:

5.

2. The method for preparing a platinum black catalyst with controllable particle size using amidine ligands according to claim 1, characterized in that, In step (1), the platinum salt includes one or more combinations of ammonium chloroplatinate, chloroplatinic acid, and tetraammineplatinum nitrate; The mass ratio of platinum to water in the platinum salt is 1:50-1:300; The monohydric alcohol is a monohydric alcohol with 1-4 carbon atoms, including one or more combinations of n-propanol, isopropanol and ethanol, and the mass ratio of platinum to monohydric alcohol in the platinum salt is 1:40-1:

100.

3. The method for preparing a platinum black catalyst with controllable particle size using amidine ligands according to claim 1, characterized in that, In step (3), the alkaline substance includes one or more combinations of sodium hydroxide, potassium hydroxide, and sodium carbonate; The drying temperature is 40-60℃, and the drying time is 8-24 h.

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