One-dimensional nanowire structure monatomic alloy catalyst and preparation method and application thereof

Abstract

The application belongs to the technical field of nanomaterials and electrocatalysis, and particularly relates to a one-dimensional nanowire structure monatomic alloy catalyst, a preparation method and application. The catalyst comprises a carrier and an active component, the structure of the active component is that Pt is dispersed in the form of monatomic on the surface of a nanowire of a base metal M, the M comprises one or more of Au, Ag, Ru, Pd, Rh, Ir and Os, and the active component is anchored on the carrier. The catalyst has an excellent one-dimensional nanowire structure with outstanding stability, the preparation process is simple, the effective product yield is high, and the prepared platinum-based catalyst material has superior oxygen reduction electrocatalytic performance and stability.

Description

Technical Field

[0001] This invention belongs to the field of nanomaterials and electrocatalysis technology, specifically relating to a one-dimensional nanowire structure single-atom alloy catalyst, its preparation method, and its application. Background Technology

[0002] Among renewable energy sources, hydrogen has become a key focus for researchers in its development and utilization due to its diverse sources, high driving efficiency, and the fact that its emissions during operation are primarily water with no environmental pollution. Proton exchange membrane fuel cells, a novel electrochemical energy conversion and storage facility with wide applications in transportation, construction, industry, and more efficient energy storage, are devices that generate electricity through the chemical reaction of hydrogen and oxygen.

[0003] However, in practical applications, the presence of gaseous impurities such as CO in hydrogen gas can easily poison existing catalysts, hindering the electrochemical reactions occurring on the surface of fuel cell electrodes—significantly impeding the widespread application of proton exchange membrane fuel cell technology. Therefore, catalyst materials exhibiting excellent anti-poisoning activity and stability in high-potential acidic electrolytes are needed to enhance and promote electrode reactions. The platinum-carbon catalyst Vulcan XC-72R, with its low specific surface area, does not adequately limit the migration, aggregation, and shedding of platinum under high-potential, strongly acidic conditions; therefore, its stability has always been a key area for improvement.

[0004] Currently, metal alloying can effectively reduce the amount of precious metals used, and the interaction of alloys can simultaneously improve the stability and activity of catalysts. Most current alloy preparation methods are solvothermal, requiring specific organic solvents, and the morphology and size of the prepared catalysts are difficult to control, with ligand residues remaining on the surface. Hydrothermal methods, on the other hand, are wet chemical reactions carried out in a closed container. Water or other solvents are added to the sealed container, and heating creates a high-temperature, high-pressure environment to allow the precursors to react and crystallize. Hydrothermal methods differ from other wet chemical methods in that their commonly used temperature is between 130 and 250°C, and they can obtain products with complete crystal forms, uniform particle size distribution, and good dispersibility without high-temperature treatment. However, traditional hydrothermal methods have a long process flow, making them unsuitable for industrialization. Summary of the Invention

[0005] This invention addresses the shortcomings of current single-atom alloy catalysts, such as complex preparation processes, high preparation costs, and difficulty in industrial production. It provides a single-atom alloy catalyst based on a one-dimensional nanowire structure and its preparation method using a hydrothermal method, while also offering superior preparation results and a simpler preparation process compared to traditional hydrothermal methods.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] The present invention provides a single-atom alloy catalyst, the catalyst comprising a support and an active component, wherein the active component has the following structure: Pt is dispersed in single-atom form on the surface of a matrix metal M nanowire, wherein M includes one or more of Au, Ag, Ru, Pd, Rh, Ir, and Os; and the active component is anchored on the support.

[0008] In the above technical solution, the carrier is further described as a carbon carrier or a metal oxide powder; the carbon carrier includes carbon nanotubes, carbon nanospheres, and carbon nanofiber networks; the metal oxide includes silicon dioxide, titanium dioxide, tin-antimony oxide, magnesium oxide, and manganese oxide.

[0009] Another aspect of the present invention provides a method for preparing the above-mentioned catalyst, the method comprising the following steps:

[0010] S1. Disperse the carrier in water and ultrasonically stir to obtain solution A;

[0011] S2. Disperse the platinum precursor solution and the M metal precursor solution in water, add surfactant and reducing agent, and mix to obtain solution B;

[0012] S3. Add solution A obtained in step S1 and solution B obtained in step S2 into the reaction vessel and stir in real time. At the same time, place the reaction vessel in an oven to react. After the reaction is completed, the alloy catalyst pre-product is obtained.

[0013] S4. The alloy catalyst pre-product obtained in step S3 is washed with water by centrifugation and then dried to obtain alloy catalyst pre-product powder.

[0014] S5. The alloy catalyst pre-finished powder obtained in step S4 is cleaned with a cleaning agent solvent, sealed and placed in a fume hood for stirring treatment, then washed with water by centrifugation and dried to obtain a one-dimensional nanowire structured platinum single-atom alloy catalyst.

[0015] In the above technical solution, further, in step S1, the mass ratio of the carrier to water is 1:1-10.

[0016] In the above technical solution, further, in step S2, the platinum precursor is one or more of chloroplatinic acid (H2PtCl6), dichlorotetraaminoplatinum (Pt(NH3)4Cl2), dichlorohexaaminoplatinum (Pt(NH3)6Cl2), and dinitrosodiaminoplatinum (Pt(NO2)2(NH3)2); the M metal precursor includes one or more of salts and acids containing the M metal.

[0017] The reducing agent is one or more of ascorbic acid, ethylene glycol, and hydrazine hydrate;

[0018] The surfactant is one or more of polyvinylpyrrolidone (PVP), carboxymethyl cellulose (CMC), methyl cellulose (MC), polyvinyl alcohol (PVA), and sodium alginate;

[0019] The molar ratio of the platinum precursor solution to the M metal precursor solution is 1:10-50;

[0020] The molar ratio of the platinum precursor solution to water is 1:10-50;

[0021] The molar ratio of the surfactant to the M metal precursor is 0.1-1:1;

[0022] The molar ratio of the reducing agent to the M metal precursor is 0.5-60:1.

[0023] Further, in step S3 of the above technical solution, when the oven temperature is 60-120℃ and the stirring speed of the reactor is set to 100-300 rpm / min, after 0.5-1 h, the platinum precursor and M precursor in the solution are adsorbed onto the support; when the oven temperature is 120-140℃ and the stirring speed of the reactor is set to 100-500 rpm / min, after 0.5-1 h, the platinum precursor and M precursor in the solution are reduced in situ onto the support; when the oven temperature is 140-180℃ and the stirring speed of the reactor is set to 500-800 rpm / min, after 0.5-1 h, the solution system is completely mixed.

[0024] In the above technical solution, further, in step S4, the number of centrifugal washing cycles is 4-6.

[0025] The drying temperature is 60-80℃, and the drying time is 12-18h.

[0026] In the above technical solution, further, in step S5, the cleaning agent solvent is one or more of tert-butanol, tetrahydrofuran, acetone, and methanol;

[0027] The molar ratio of the cleaning agent solvent to the alloy catalyst pre-finished powder is 10-100:1;

[0028] The sealing and stirring time is 1-3 hours, and the stirring speed is 1000-1500 rpm / min;

[0029] The number of centrifugal washing cycles is 2-6;

[0030] The drying temperature is 60-80℃, and the drying time is 12-18h.

[0031] In another aspect, the present invention provides the application of the above-mentioned catalyst in a proton exchange membrane fuel cell.

[0032] The beneficial effects of this invention are as follows:

[0033] 1. The catalyst of the present invention has a one-dimensional nanowire structure. Compared with nanoparticle catalysts, the one-dimensional nanowire structure has a good electron-ion transport channel, which can realize the efficient transport of electrons in the transport channel, thereby improving conductivity and catalytic activity. In addition, the Pt metal of the present invention is uniformly inserted into the surface of the nanowire matrix metal in the form of single atoms, that is, the single-atom metal is anchored on the surface of the support metal and is not easy to migrate. Therefore, it is a synergistic electrocatalytic nanomaterial with excellent electrocatalytic performance and outstanding stability.

[0034] 2. This invention employs a one-step hydrothermal method to achieve the desired catalyst structure. Compared to the traditional method of using a hydrothermal method in steps to prepare the catalyst separately, this invention directly achieves the precursor reduction process in one step through hydrothermal temperature, reactor stirring, and a segmented design of the reaction process. This method realizes the one-step preparation of platinum single-atom nanowire one-dimensional structure catalyst composite materials. The preparation process is simple, the one-dimensional structure of the catalyst is conducive to the exposure of active sites and reaction mass transfer, and it has obvious structural advantages. It lays the structural foundation for the high stability of the catalyst in high potential, strongly corrosive acidic environments. The method has low cost, simple equipment requirements, and a short preparation process, and has excellent industrialization prospects.

[0035] 3. In the preparation of platinum single-atom alloy nanowire structure catalyst, this invention effectively controls the reaction process and crystal growth by adjusting the ratio and type of surfactant and reducing agent. It can realize the in-situ reduction of platinum salt on the support substrate, fully realize the uniform dispersion of platinum metal in the nanowire structure in the final catalyst, and effectively avoid migration, Oswald ripening and desquamation failure in electrochemical applications. It is of great significance to improve the overall performance and stability of the catalyst.

[0036] 4. This invention uses water as a solvent. Combined with the one-step hydrothermal method, it achieves low-temperature reduction to obtain catalysts with smaller particle sizes, thereby obtaining a larger specific surface area and improving reaction efficiency. Furthermore, by incorporating the segmented stirring, temperature, and time control design in the one-step hydrothermal method, it is possible to achieve stirring at different temperatures and speeds, enabling one-dimensional structure control of the catalyst, in-situ reduction of platinum and M precursors, and embedding of Pt single atoms into the X metal. The segmented stirring design utilizes the dissolution-recrystallization principle of the hydrothermal process, strengthening convection inside and outside the reactor to deliver ion clusters to the seed crystal growth zone, forming a supersaturated solution, which then crystallizes.

[0037] 5. This invention creates specific defect sites on the support to enhance the interaction between the loaded metal and the support. The matrix metal is mainly chemically bonded and anchored to the defect sites and oxygen-containing groups of the carbon support. The catalyst has a high specific surface area, and thus the formed single-atom catalyst has a high metal mass content, exceeding 4 wt%.

[0038] 6. This invention eliminates the need for highly corrosive liquids and gases such as acid washing in all stages of catalyst processing. Furthermore, the closed-loop conditions of hydrothermal synthesis do not harm human health, reducing environmental pollution. This is of great significance for improving the overall environmental protection properties of catalyst preparation and lays the foundation for the industrial application of catalysts. Attached Figure Description

[0039] Figure 1 The image shows the microstructure of the one-dimensional nanowire structure Pt single-atom alloy catalyst prepared in Example 1, where a is 20 nm and b is 10 nm.

[0040] Figure 2 The polarization curve of the one-dimensional nanowire structure Pt single-atom alloy catalyst prepared in Example 1 is shown.

[0041] Figure 3 Polarization curves of the one-dimensional nanowire structure Pt single-atom alloy catalyst prepared in step 2;

[0042] Figure 4 The polarization curve of the one-dimensional nanowire structure Pt single-atom alloy catalyst prepared in Example 3 is shown. Detailed Implementation

[0043] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention. Unless otherwise specified, the methods described are conventional methods. Unless otherwise specified, the raw materials can be obtained from publicly available commercial channels.

[0044] This invention addresses the limitations in the development of proton exchange membrane fuel cells and the problem of low metal atom utilization in platinum-carbon oxygen reduction electrocatalysts. The method has advantages such as simple process steps, short process flow, and adjustable morphology and structure. The prepared catalyst has a large specific surface area, and its catalytic activity and stability are significantly better than those of commercial Pt / C catalysts. The entire synthesis route has low equipment requirements and good process stability, and has important value for industrial application.

[0045] Example 1

[0046] S1. Disperse 5 mg of titanium dioxide carrier in 50 ml of water and stir ultrasonically to obtain solution A;

[0047] S2. Disperse 0.1 mol chloroplatinic acid solution and 1 mol chloroauric acid precursor solution in 18 ml of water, add 0.1 mol polyvinylpyrrolidone and 0.5 mol ascorbic acid, and mix to obtain solution B;

[0048] S3. Solution A from S1 and solution B from S2 are added together to a reaction vessel equipped with a stirring function and stirred in real time. Simultaneously, the reaction vessel is placed in an oven for reaction. When the oven temperature is 60℃ and the stirring speed is set to 100 rpm / min, after 0.5 h, the platinum precursor and M precursor in the solution are adsorbed onto the support. When the oven temperature is 120℃ and the stirring speed is set to 100 rpm / min, after 0.5 h, the platinum precursor and M precursor in the solution are reduced in situ onto the support. When the oven temperature is 140℃ and the stirring speed is set to 500 rpm / min, after 0.5 h, the solution system is completely mixed. After the reaction is complete, a pre-finished platinum single-atom alloy catalyst with a one-dimensional nanowire structure is obtained.

[0049] S4. After washing the alloy catalyst pre-product of S3 with water by centrifugation 4 times, put it into an oven to dry again. The oven temperature is 60℃ and the drying time is 12h to obtain the platinum single-atom alloy catalyst pre-product powder with one-dimensional nanowire structure.

[0050] S5. Weigh 50 mg of the S4 catalyst pre-processing powder and add 23 ml of tert-butanol solvent to a beaker to wash away organic molecules on the catalyst surface. After sealing, place the beaker in a fume hood and stir at 1000 rpm / min for 1 hour. After stirring, wash twice with water by centrifugation, and then dry in an oven at 60℃ for 12 hours. After drying, a one-dimensional nanowire structured platinum single-atom alloy catalyst is obtained, designated as Sample 1.

[0051] The microstructure of the one-dimensional nanowire structure Pt single-atom alloy catalyst prepared in Example 1 is as follows: Figure 1 As shown, by Figure 1 (a) It can be seen that the catalysts prepared by the method of the present invention all exist in the form of nanowire structures, with a nanowire length of about 10-30 nanometers and a nanowire diameter of 1-2 nanometers. Figure 1 (b) High-resolution images clearly show that single atoms are uniformly distributed on the surface of the nanowire matrix metal, forming a uniformly dispersed single-atom alloy.

[0052] The catalyst prepared in Example 1 was dispersed in anhydrous ethanol and sonicated for 30 min to obtain a homogeneous dispersion. 20 μL of this dispersion was pipetted onto a 5 mm diameter glassy carbon electrode and dried at 60 °C. Then, 1 μL of 0.5 wt.% Nafion solution was pipetted onto the catalyst layer and dried in air to obtain the working electrode. Cyclic voltammetry was performed in a high-purity N2-saturated 0.1 mol / L HClO4 solution at a scan rate of 50 mV / s and a scan range of 0.0–1.10 V (vs. RHE) for 30 cycles, yielding an electrochemically active area of ​​62.5 m². 2 / g, after cyclic voltammetry scanning of the working electrode until the catalyst surface is clean and stable, it is removed for LSV testing. The solution is 0.1 mol / L HClO4 saturated with H2 containing 5 ppm CO impurities. The scan rate is 10 mV / s, the scan range is 0–0.5 V, and the rotating disk electrode speed is 1600 rpm / min. The polarization curve is shown below. Figure 2 As shown. Its mass activity is 138 A / g, and its retention rate after 20,000 cycles of current is 65%.

[0053] Example 2

[0054] S1. Disperse 5 mg of carbon nanotube carrier in 500 ml of water and stir ultrasonically to obtain solution A;

[0055] S2. Disperse 0.1 mol chloroplatinic acid solution and 5 mol ruthenium acetylacetonate precursor solution in 90 ml of water, add 1 mol carboxymethyl cellulose and 30 mol ethylene glycol, and mix to obtain solution B;

[0056] S3. Solution A from S1 and solution B from S2 are added together to a reaction vessel equipped with a stirring function and stirred in real time. Simultaneously, the reaction vessel is placed in an oven for reaction. When the oven temperature is 120℃ and the stirring speed is set to 300 rpm / min, after 1 hour, the platinum precursor and M precursor in the solution are adsorbed onto the support. When the oven temperature is 140℃ and the stirring speed is set to 500 rpm / min, after 1 hour, the platinum precursor and M precursor in the solution are reduced in situ onto the support. When the oven temperature is 180℃ and the stirring speed is set to 800 rpm / min, after 1 hour, the solution system is completely mixed. After the reaction is completed, a pre-finished platinum single-atom alloy catalyst with a one-dimensional nanowire structure is obtained.

[0057] S4. After washing the alloy catalyst pre-product of S3 with water by centrifugation 6 times, put it into an oven to dry again. The oven temperature is 80℃ and the drying time is 18h to obtain the platinum single-atom alloy catalyst pre-product powder with one-dimensional nanowire structure.

[0058] S5. Weigh 50 mg of the S4 catalyst pre-finished powder, add 180 ml of acetone solvent to a beaker to wash away organic molecules on the surface of the catalyst, seal it and place it in a fume hood for stirring at a speed of 1500 rpm / min for 3 hours. After stirring, wash it 6 times with water by centrifugation, and then place it in an oven to dry at a temperature of 80℃ for 18 hours. After drying, a one-dimensional nanowire structure platinum single-atom alloy catalyst is obtained.

[0059] The catalyst prepared in Example 2 is designated as Sample 2. Using the same testing methods and conditions as in Example 1, CV testing was performed. As shown in Table 1, its electrochemical active area is 64.5 m². 2 / g, LSV test polarization curve as shown Figure 3 As shown, its mass activity is 142 A / g, and its retention rate after 20,000 cycles of current is 76%.

[0060] Example 3

[0061] S1. Disperse 5 mg of titanium dioxide carrier in 275 ml of water and stir ultrasonically to obtain solution A;

[0062] S2. Disperse 0.1 mol chloroplatinic acid solution and 3 mol palladium chloride precursor solution in 99 ml of water, add 0.5 mol polyvinylpyrrolidone and 14.75 mol ascorbic acid, and mix to obtain solution B;

[0063] S3. Solution A from S1 and solution B from S2 are added together to a reaction vessel equipped with a stirrer for real-time stirring. Simultaneously, the reaction vessel is placed in an oven for reaction. When the oven temperature is 90℃ and the stirring speed is set to 200 rpm / min, after 0.75 h, the platinum precursor and M precursor in the solution are adsorbed onto the support. When the oven temperature is 130℃ and the stirring speed is set to 300 rpm / min, after 0.75 h, the platinum precursor and M precursor in the solution are reduced in situ onto the support. When the oven temperature is 160℃ and the stirring speed is set to 650 rpm / min, after 0.75 h, the solution system is completely mixed. After the reaction, a one-dimensional nanowire structured platinum single-atom alloy catalyst pre-product is obtained.

[0064] S4. After washing the alloy catalyst pre-product from S3 four times with water by centrifugation, it is dried again in an oven at 60℃ for 12 hours. This yields a platinum single-atom alloy catalyst pre-product powder with a one-dimensional nanowire structure.

[0065] S5. Weigh 50 mg of the S4 catalyst pre-finished powder and add 23 ml of tert-butanol solvent to a beaker to wash away organic molecules on the catalyst surface. After sealing, place the beaker in a fume hood and stir at 1250 rpm / min for 2 hours. After stirring, wash the catalyst four times with water by centrifugation, and then dry it in an oven at 70℃ for 15 hours. After drying, a one-dimensional nanowire structured platinum single-atom alloy catalyst is obtained.

[0066] The catalyst prepared in Example 3 is designated as Sample 3. Using the same testing methods and conditions as in Example 1, CV testing was performed. As shown in Table 1, its electrochemical active area is 63.2 m². 2 / g, LSV test polarization curve as shown Figure 4 As shown, its mass activity is 140 A / g, and its retention rate after 2000 cycles of current is 67%.

[0067] Comparative Example 1

[0068] S1. Disperse 5 mg of titanium dioxide carrier in 50 ml of water and sonicate. Disperse 0.1 mol of chloroplatinic acid solution and 1 mol of chloroauric acid precursor solution in 18 ml of water and sonicate to obtain solution A;

[0069] S2. Add 0.1 mol of polyvinylpyrrolidone and 0.5 mol of ascorbic acid to solution A, and mix to obtain solution B;

[0070] S3. Solution A from S1 and solution B from S2 are added together to a reaction vessel equipped with a stirrer and stirred in real time. Simultaneously, the reaction vessel is placed in an oven for reaction, with the stirring speed at 300 rpm / min to ensure complete mixing of the solutions. After the reaction, a pre-finished platinum single-atom alloy catalyst with a one-dimensional nanowire structure is obtained.

[0071] S4. After washing the alloy catalyst pre-product from S3 four times with water by centrifugation, it is dried again in an oven at 60℃ for 12 hours. This yields a platinum single-atom alloy catalyst pre-product powder with a one-dimensional nanowire structure.

[0072] S5. Weigh 50 mg of the S4 catalyst pre-finished powder and add 23 ml of tert-butanol solvent to a beaker to wash away organic molecules on the catalyst surface. After sealing, place the beaker in a fume hood and stir at 1000 rpm / min for 1 hour. After stirring, wash twice with water by centrifugation, and then dry in an oven at 60℃ for 12 hours. After drying, a one-dimensional nanowire structured platinum single-atom alloy catalyst is obtained.

[0073] Comparative Example 2

[0074] S1. Disperse 5 mg of titanium dioxide carrier in 275 ml of water and stir ultrasonically to obtain solution A;

[0075] S2. Disperse 0.1 mol chloroplatinic acid solution and 3 mol chloroauric acid precursor solution in 99 ml of water, add 0.5 mol polyvinylpyrrolidone and 14.75 mol ascorbic acid, and mix to obtain solution B;

[0076] S3. Solution A from S1 and solution B from S2 are added together to a reaction vessel equipped with a stirrer and stirred in real time. Simultaneously, the reaction vessel is placed in an oven for reaction. The stirring speed of the reaction vessel is set to 500 rpm / min. After 3 hours, the solution system is completely mixed. After the reaction is complete, a pre-finished platinum single-atom alloy catalyst with a one-dimensional nanowire structure is obtained.

[0077] S4. After washing the alloy catalyst pre-product from S3 four times with water by centrifugation, it is dried again in an oven at 60℃ for 12 hours. This yields a platinum single-atom alloy catalyst pre-product powder with a one-dimensional nanowire structure.

[0078] S5. Weigh 50 mg of the S4 catalyst pre-finished powder and add 23 ml of tert-butanol solvent to a beaker to wash away organic molecules on the catalyst surface. After sealing, place the beaker in a fume hood and stir at 1000 rpm / min for 1 hour. After stirring, wash twice with water by centrifugation, and then dry in an oven at 60℃ for 12 hours. After drying, a one-dimensional nanowire structured platinum single-atom alloy catalyst is obtained.

[0079] Comparative Example 3

[0080] S1. Disperse 5 mg of titanium dioxide carrier in 50 ml of ethanol and stir ultrasonically to obtain solution A;

[0081] S2. Disperse 0.1 mol chloroplatinic acid solution and 1 mol chloroauric acid precursor solution in 18 ml ethanol, add 0.1 mol polyvinylpyrrolidone and 0.5 mol ascorbic acid, and mix to obtain solution B;

[0082] S3. Solution A from S1 and solution B from S2 are added together to a reaction vessel equipped with a stirrer and stirred in real time. Simultaneously, the reaction vessel is placed in an oven for reaction. When the oven temperature is 60℃ and the stirring speed is set to 100 rpm / min, after 0.5 h, the platinum precursor and M precursor in the solution are adsorbed onto the support. When the oven temperature is 120℃ and the stirring speed is set to 100 rpm / min, after 0.5 h, the platinum precursor and M precursor in the solution are reduced in situ onto the support. When the oven temperature is 140℃ and the stirring speed is set to 500 rpm / min, after 0.5 h, the solution system is completely mixed. After the reaction, a one-dimensional nanowire structured platinum single-atom alloy catalyst pre-product is obtained.

[0083] S4. After washing the alloy catalyst pre-product from S3 four times with water by centrifugation, it is dried again in an oven at 60℃ for 12 hours. This yields a platinum single-atom alloy catalyst pre-product powder with a one-dimensional nanowire structure.

[0084] S5. Weigh 50 mg of the S4 catalyst pre-finished powder and add 23 ml of tert-butanol solvent to a beaker to wash away organic molecules on the catalyst surface. After sealing, place the beaker in a fume hood and stir at 1000 rpm / min for 1 hour. After stirring, wash twice with water by centrifugation, and then dry in an oven at 60℃ for 12 hours. After drying, a one-dimensional nanowire structured platinum single-atom alloy catalyst is obtained.

[0085] Using the same testing methods and conditions as in Example 1, the catalysts prepared in Comparative Examples 1-3 were subjected to CV and LSV tests, and the relevant data are recorded in Table 1. In summary, since Comparative Example 1 did not use a one-step hydrothermal method, as shown in Table 1, the conductivity and catalytic activity of the catalyst prepared therefrom are not as good as those of this application.

[0086] Since Comparative Example 3 was prepared using ethanol solvent without water, as shown in Table 1, the conductivity and catalytic activity of the catalyst prepared by it are not as good as those of this application.

[0087] Table 1

[0088]

[0089]

Claims

1. A method for preparing a single-atom alloy catalyst, characterized by, The method comprises the following steps: S1, dispersing the carrier in water, and obtaining solution A after ultrasonic stirring; S2, dispersing the platinum precursor solution and the M metal precursor solution in water, adding a surfactant and a reducing agent, and obtaining solution B after mixing; S3, adding solution A obtained in step S1 and solution B obtained in step S2 into a reaction kettle, stirring in real time in the reaction kettle, and placing the reaction kettle in an oven for reaction, and obtaining an alloy catalyst pre-product after the reaction; S4, centrifugal washing the alloy catalyst pre-product obtained in step S3 with water, and then drying to obtain an alloy catalyst pre-product powder; S5, cleaning the alloy catalyst pre-product powder obtained in step S4 with a cleaning agent solvent, sealing and stirring, then centrifugal washing with water, and drying to obtain a one-dimensional nanowire structure platinum monatomic alloy catalyst; In step S3, when the oven temperature is 60-120℃, the stirring speed of the reaction kettle is set to 100-300 rpm / min, and after 0.5-1h, the platinum precursor and the M precursor in the solution are adsorbed on the carrier; when the oven temperature is 120-140℃, the stirring speed of the reaction kettle is set to 100-500 rpm / min, and after 0.5-1h, the platinum precursor and the M precursor in the solution are in-situ reduced on the carrier; when the oven temperature is 140-180℃, the stirring speed of the reaction kettle is set to 500-800 rpm / min, and after 0.5-1h, the solution system is completely mixed.

2. The method of claim 1, wherein: In step S1, the mass ratio of the carrier to water is 1:1-10.

3. The method of claim 1, wherein: In step S1, the carrier is a carbon carrier or a metal oxide powder; the carbon carrier includes carbon nanotubes, carbon nanospheres, and carbon nanofiber webs; the metal oxide includes silicon dioxide, titanium dioxide, tin antimony oxide, magnesium oxide, and manganese oxide.

4. The method of claim 1, wherein: In step S2, the platinum precursor is one or more of chloroplatinic acid (H2PtCl6), dichlorotetraammine platinum (Pt(NH3)4Cl2), dichlorohexaammine platinum (Pt(NH3)6Cl2), and dinitrosodiaminoplatinum (Pt(NO2)2(NH3)2); the M metal precursor includes one or more of a salt and an acid containing the M metal; The reducing agent is one or more of ascorbic acid, ethylene glycol, and hydrazine hydrate; The surfactant is one or more of polyvinylpyrrolidone (PVP), carboxymethyl cellulose (CMC), methyl cellulose (MC), polyvinyl alcohol (PVA), and sodium alginate; The molar ratio of the platinum precursor solution to the M metal precursor solution is 1:10-50; The molar ratio of the platinum precursor solution to water is 1:10-50; The molar ratio of the surfactant to the M metal precursor is 0.1-1:1; The molar ratio of the reducing agent to the M metal precursor is 0.5-60:

1.

5. The method of claim 1, wherein: In step S4, the centrifugal washing frequency is 4-6 times; The drying temperature is 60-80℃, and the drying time is 12-18h.

6. The method of claim 1, wherein: In step S5, the cleaning agent solvent is one or more of tert-butyl alcohol, tetrahydrofuran, acetone, and methanol; The molar ratio of the cleaning agent solvent to the alloy catalyst pre-product powder is 10-100:1; The sealing stirring time is 1-3h, and the stirring speed is 1000-1500rpm / min; The centrifugal washing times are 2-6 times; The drying temperature is 60-80℃, and the drying time is 12-18h.

7. A monatomic alloy catalyst prepared by the process of any one of claims 1 to 6, characterized by: The catalyst comprises a carrier and an active component, and the structure of the active component is that Pt is dispersed in the form of single atom on the surface of a matrix metal M nanowire, wherein the M comprises one or more of Au, Ag, Ru, Pd, Rh, Ir and Os; and the active component is anchored on the carrier.

8. Use of the catalyst of claim 7 in a proton exchange membrane fuel cell.

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