Preparation method and application of a supported low-Pt core-shell fuel cell catalyst

Abstract

This invention belongs to the field of electrocatalyst technology, specifically to a method for preparing a supported low-Pt core-shell fuel cell catalyst and its application. This method utilizes an aqueous method, with the addition of a trace amount of surfactant. After a two-step reduction with a reducing agent, followed by filtration, washing, and drying, the material is placed in a tubular furnace, heated to a specific temperature for annealing, and cooled to produce the finished carbon-supported low-Pt core-shell electrocatalyst. The catalyst is small and uniformly dispersed; the process is simple and efficient, enabling the mass production of highly stable core-shell catalysts.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrocatalysts, and in particular relates to a preparation method and application of a supported low-Pt core-shell fuel cell catalyst. Background Art

[0002] Hydrogen is an abundant, green, low-carbon, and widely applicable secondary energy source, and is gradually becoming a key driver of global energy transition. Proton exchange membrane fuel cells (PEMFCs) are currently a key research and development focus in hydrogen energy applications, but they still face challenges in commercialization, including waste heat generation, sensitivity to fuel impurities, expensive catalysts, and slow oxygen reduction reaction (ORR) rates. Catalysts account for over 30% of the total cost, as PEMFCs rely heavily on the precious metal Pt. However, Pt's high price and limited reserves have resulted in high manufacturing costs for PEMFCs, severely limiting their commercialization. The development of new, high-performance, low-cost catalysts is crucial for advancing fuel cell development. To reduce catalyst costs while maintaining high catalytic activity, strategies include designing low-Pt catalysts. These strategies include engineering the shape of catalytic particles to control the arrangement of surface atoms; increasing single-atom utilization; alloying Pt with relatively inexpensive transition metals (Ms) to modify the Pt electronic structure through ligand effects; and constructing core-shell structures to enhance Pt utilization. However, the synthesis process of electrocatalysts with controlled morphology is cumbersome, difficult to scale up, and single atoms have poor durability and are prone to deactivation. Dispersing Pt on the surface of non-platinum nanoparticles to form a core-shell catalyst can effectively improve the utilization efficiency of the precious metal platinum. Furthermore, due to the unique surface electronic structure and special interactions between the core and shell, Pt-based core-shell catalysts exhibit higher catalytic activity and stability.

[0003] Therefore, it is of great value and significance to develop a small-sized, simple and efficient preparation process and mass-producible supported low-Pt core-shell fuel cell catalyst. Summary of the Invention

[0004] The purpose of the present invention is to solve the above-mentioned problems in the prior art and provide a preparation method and application of a supported low-Pt core-shell fuel cell catalyst for oxygen reduction reaction. The preparation method uses trace surfactants, low-concentration salt solutions and reducing agents to make the catalyst particles uniform in size, with a clear core-shell structure, good activity and stability, and can be adapted to the preparation of various platinum-based alloy components.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for preparing a supported low-Pt core-shell fuel cell catalyst comprises the following steps:

[0007] (1) dispersing the carbon support in a surfactant aqueous solution, adding a Cu metal salt aqueous solution and an Au metal salt aqueous solution under vigorous stirring at a temperature of 0 to 25° C., and adjusting the solution pH to ≥ 7 with an alkaline solution; then adding a reducing agent aqueous solution and reacting for 0.1 to 1.5 hours; then adjusting the solution pH to ≥ 7 with an alkaline solution, adding a Pt metal salt aqueous solution, and then adding a reducing agent aqueous solution and reacting for 0.1 to 5 hours, preferably 0.1 to 1.5 hours;

[0008] (2) filtering the obtained mixed solution, washing, and drying the obtained material, placing it in a porcelain boat, placing it in a tube furnace, introducing a certain gas, and keeping it at a certain temperature. After cooling, a carbon-supported low-Pt core-shell (AuCu@Pt / C) fuel cell catalyst material is finally obtained;

[0009] The catalyst is a carbon-supported platinum-copper-gold alloy material, the loading of the platinum-copper-gold alloy in the carbon-supported platinum-copper-gold alloy material is 10-60wt% (preferably 10-50%), and the atomic ratio of Au, Cu and Pt is 1:1:1-1:3:7-1:4:9, preferably 1:1:1-1:3:7.

[0010] Furthermore, in step (1), the carbon support is dispersed in the surfactant aqueous solution at a concentration of 0.01 to 2 mg mL -1 , preferably 0.01-0.1 mg mL -1 ;

[0011] The concentration of the surfactant aqueous solution is 10 to 100 mmol L -1 , preferably 10 to 60 mmol L -1 , more preferably 10 to 50 mmol L -1 ;

[0012] The concentration of the metal salt aqueous solution is 0.1 to 60 mmol L -1 , preferably 1 to 40 mmol L -1 ;

[0013] The concentration of the reducing agent aqueous solution is 0.5 to 400 mmol L -1 , preferably 1 to 60 mmol L -1 , more preferably 50 to 100 mmol L -1 ;

[0014] The reducing agent added each time is in excess relative to the total amount of Cu metal salt, Au metal salt and Pt metal salt. The amount of the reducing agent added each time is 2 to 10 times, preferably 2 to 5 times, the total amount of Cu metal salt, Au metal salt and Pt metal salt.

[0015] Furthermore, the carbon support includes at least one of carbon black materials (such as Vulcan XC-72, BP2000, Ketjen Black EC-300J, ECP-600JD), fullerenes, carbon nanotubes, carbon nanotube aerogels, carbon aerogel materials, metal organic framework pyrolytic carbon materials, graphene, graphene aerogels, and carbon nanocages.

[0016] Furthermore, the surfactant is at least one of a cationic surfactant, an anionic surfactant, an amphoteric surfactant, and a nonionic surfactant; preferably, the cationic surfactant is at least one of alkyltrimethylammonium chloride, alkyldimethylbenzylammonium chloride, and dialkyldimethylammonium chloride; the anionic surfactant is at least one of cyclohexane salts, alkylbenzenesulfonates, alkylsulfonates, and alkyl sulfates (such as sodium dodecyl sulfate (SDS)); the amphoteric surfactant is at least one of γ-(methacryloyloxy)propyltrimethoxysilane, bis-(3-triethoxysilylpropyl)amine, and bis-(trimethoxysilylpropyl)amine; and the nonionic surfactant is at least one of Tween 20, Triton X-100, polyethylene glycol, and Surfynol 485.

[0017] Furthermore, the platinum metal salt can be one or a mixture of two or more of chloroplatinic acid, chloroplatinous acid, potassium chloroplatinate, potassium chloroplatinite, sodium chloroplatinate, sodium chloroplatinite, ammonium chloroplatinate, and ammonium chloroplatinite, but is not limited thereto.

[0018] Furthermore, the copper metal salt may be one or a mixture of two or more of cupric chloride, cuprous chloride, cupric nitrate, copper sulfate, cuprous nitrate, cuprous sulfate, and copper acetate, but is not limited thereto.

[0019] Furthermore, the gold metal salt can be one or a mixture of two or more of chloroauric acid, sodium chloroaurate, ammonium tetrachloroaurate, potassium chloroaurate, and potassium gold citrate, but is not limited thereto.

[0020] Furthermore, in step (1), the carbon support is dispersed in a 50-100 μL SDS aqueous solution and the solution is mixed by ultrasonication to make it uniform.

[0021] Furthermore, in step (1), the rotation speed of the vigorous stirring is greater than 200 rpm.

[0022] Furthermore, in step (1), after the reducing agent aqueous solution is added for the first time and reacted for 0.1 to 1.5 hours, the pH of the solution is first adjusted to ≤ 7 with an acid to destroy the excess reducing agent, and then the pH of the solution is adjusted to ≥ 7 with an alkaline solution, and then the Pt metal salt aqueous solution is added, and then the reducing agent aqueous solution is added and reacted for 0.1 to 5 hours.

[0023] Furthermore, in step (1), before the first addition of the reducing agent, the solution is aerated with an inert gas for 5-30 minutes to remove the oxidizing gas.

[0024] Furthermore, in step (1), the reaction atmosphere is an inert gas, which may be helium, argon, or nitrogen, but is not limited thereto.

[0025] Furthermore, in step (2), the holding temperature is 100-400° C., and the holding time is 1-3 hours; the temperature is raised to the holding temperature at a certain rate, and the heating rate is 1-10° C. / min.

[0026] Furthermore, in step (2), the reaction atmosphere can be one or more of helium, argon, nitrogen, hydrogen, a hydrogen-argon mixture (hydrogen accounts for 5-30% by volume, for example, 5, 10, 20, 30%), CO or low-carbon alkanes (C2-C3 chain alkanes), but is not limited thereto.

[0027] Furthermore, the reducing agent may be sodium borohydride, potassium borohydride, magnesium borohydride, formaldehyde, formic acid, citric acid, glucose, sucrose, or ascorbic acid, but is not limited thereto.

[0028] Furthermore, the acid may be one or a mixture of two or more of hydrochloric acid, sulfuric acid, perchloric acid, nitric acid, oxalic acid, sulfurous acid, phosphoric acid, nitrous acid, carbonic acid, formic acid, lactic acid, benzoic acid, and acetic acid, but is not limited thereto.

[0029] Furthermore, the alkali may be one or a mixture of two or more of sodium hydroxide, potassium hydroxide, barium hydroxide, and ammonia water, but is not limited thereto.

[0030] Furthermore, in step (2), the drying time is 1 to 24 hours, the drying temperature is 60 to 90° C., and the drying environment is vacuum.

[0031] The present invention also relates to a supported low-Pt core-shell fuel cell catalyst obtained by protecting the above-mentioned preparation method. The catalyst includes low-Pt core-shell alloy particles and a catalyst carrier. The low-Pt core-shell alloy particles are supported on the catalyst carrier, and the catalyst carrier is a carbon carrier. The low-Pt core-shell alloy particles in the supported low-Pt core-shell alloy material are uniformly dispersed on the surface of the carbon carrier. The nanoparticles obtained by the present invention have good size uniformity and good electrocatalytic activity and durability.

[0032] Furthermore, the low-Pt core-shell alloy particles include a shell layer and a core, the shell layer is Pt or PtCu alloy, and the core is AuCu alloy; the particle size of the catalyst is 2 to 5 nm; the shell layer half-encloses or covers the surface of the core; the Pt loading of the catalyst is 9-40%, preferably 20 to 30%; the copper-gold alloy loading of the core is 1 to 20%, preferably 10 to 20%.

[0033] The present invention also relates to the use of the above-mentioned supported low-Pt core-shell fuel cell catalyst in an acidic cathode oxygen reduction reaction.

[0034] The present invention uses an aqueous phase method, under the condition of adding a trace amount of surfactant, and puts the material after two-step reduction with a reducing agent and filtering, washing and drying into a tubular furnace, raises it to a specific temperature for annealing, and cools it to obtain the finished carbon-supported low-Pt core-shell electrocatalyst.

[0035] Compared with the prior art, the advantages of the technical solution of the present invention are:

[0036] The core-shell structure of the present invention exhibits good durability in acidic media, and its mass specific activity (MA) is several times that of commercial Pt / C. The half-wave potential (0.906V) is much higher than that of Pt / C (0.860V), indicating that it has excellent ORR performance.

[0037] The present invention adopts a low-temperature reduction approach, and the catalyst size is small and evenly dispersed;

[0038] The catalyst synthesis process of the present invention is simple and efficient, easy to industrialize, low in cost, and has great application potential;

[0039] The method has a wide range of applicability and can be used to synthesize core-shell alloy catalysts with different shell thicknesses. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a transmission electron microscopy (TEM) image of the catalyst obtained in Example 1, and the inset is a particle size statistical histogram.

[0041] Figure 2 The X-ray diffraction (XRD) pattern of the catalyst in Example 1 is shown.

[0042] Figure 3 The acidic cyclic voltammetry (CV) curve of Example 1 was carried out in 0.1M HClO4 aq. saturated with N2 at 25°C. -1 The scan rate was scanned in the potential range of 0 to 1.2 V vs. RHE.

[0043] Figure 4The acidic linear sweep voltammetry (LSV) curve of Example 1 was carried out in 0.1M HClO4 aq. saturated with O2 at 25°C, with a scan range of 0-1.2 V vs. RHE and a scan rate of 10 mVs -1 The LSV curve was measured and recorded in 0.1M HClO4 aq. saturated with N2 at 25°C for background correction. The scanning range was 0-1.2V vs. RHE and the scanning rate was 10mVs. -1 The ORR polarization curve can be obtained by subtracting the LSV curve of N2 saturation from the LSV curve of O2 saturation.

[0044] Figure 5 This is the thermogravimetric analysis (TGA) curve of Example 1.

[0045] Figure 6 The acidic cyclic voltammetry (CV) curve after accelerated aging (ADT) of Example 1 was obtained in 0.1 M HClO4 aq. saturated with N2 at 25°C at a speed of 500 mV s -1 The sample was scanned by CV at a scan rate of 10000 cycles in the potential range of 0.6-1.0 V vs. RHE.

[0046] Figure 7 This is the acidic linear sweep voltammetry (LSV) curve after accelerated aging (ADT) of Example 1. DETAILED DESCRIPTION

[0047] The present invention will be further described in the following examples, but are not intended to limit the present invention.

[0048] Example 1

[0049] 30 mg of ECP-600JD was diluted to 0.03 mg mL -1 The concentration of 100 μL SDS was dispersed in deionized water and ultrasonicated for 20 min. The mixture was then placed in a water bath with a speed of 1000 rpm and a temperature of 0 ° C. First, a 10 mmol L -1 Aqueous copper nitrate solution (15 mL) and aqueous chloroauric acid solution (5 mL) were added to control the ratio of Cu atoms, Au atoms and Pt atoms to 3:1:3, and then 5 mL of aqueous sodium bicarbonate solution was added to control the pH to 7-8, and then 100 mL of 1 mmol L -1 The sodium borohydride aqueous solution was used as a reducing agent and the reaction was continued for 1 hour. 2 mL of 12 mol / L hydrochloric acid was added first, followed by sodium bicarbonate to adjust the pH to 7-8, and then 15 mL of chloroplatinic acid aqueous solution was added, followed by 50 mL of 1 mmol L -1The reaction was continued for 1 hour using a sodium borohydride aqueous solution as a reducing agent. The resulting mixed solution was filtered and washed until the filtrate was neutral. The solution was then dried at 70°C overnight and ground. Heat treated at 200°C for 1 hour under a 5% hydrogen-argon atmosphere to obtain a low-Pt core-shell alloy material with a 32.4 wt.% loading, namely AuCu@Pt / C.

[0050] like Figure 1 The figure shows the transmission electron microscope (TEM) image of the AuCu@Pt / C core-shell alloy sample prepared in Example 1. Figure 1 The measured particle size distribution of the AuCu@Pt / C core-shell alloy sample prepared in this example shows an average particle size of 3.89 nm, with a Pt shell approximately 2 nm thick on the catalyst surface. Transmission electron microscopy (TEM) images demonstrate the uniform and small particle size of the core-shell catalyst prepared in this example.

[0051] like Figure 2 As shown, the XRD results show that the product obtained in this example is AuCu@Pt / C alloy.

[0052] like Figure 3 As shown, TGA determined that the loading of AuCu@Pt in the product obtained in this example was 32.4 wt.%.

[0053] like Figure 4 As shown in the acidic linear sweep voltammetry (LSV) curve of Example 1, the mass specific activity (MA) can be calculated to be 601.77 mA / mg Pt , far superior to commercial platinum carbon.

[0054] like Figure 5 As shown in the thermogravimetric analysis (TGA) curve of Example 1, the metal loading is 32%.

[0055] like Figure 6 As shown in the acidic cyclic voltammetry (CV) curve after accelerated aging (ADT) of Example 1, the increase in the oxidation peak between 0.6 and 0.7 V may be due to atomic rearrangement during the potential cycling test.

[0056] like Figure 7 As shown in the acidic linear sweep voltammetry (LSV) curve of Example 1 after accelerated aging (ADT), the half-wave potential only decays by 19 mV.

[0057] Example 2

[0058] 30mg of Vulcan XC-72 was diluted in 0.3mgmL -1The concentration of 20 mmol L was dispersed in deionized water containing 10 μL SDS, and ultrasonicated for 60 min. The mixture was then placed in a water bath with a speed of 800 rpm and a temperature of 5 °C. -1 Aqueous copper chloride solution (5 mL) and aqueous sodium chloroaurate solution (5 mL) were added to control the ratio of Cu atoms, Au atoms and Pt atoms to be 1:1:1. 10 mL of aqueous sodium bicarbonate solution was added to control the pH to 7-8, and then 100 mL of 10 mmol L -1 Ascorbic acid aqueous solution was used as a reducing agent and the reaction was continued for 4 h. After adding 1.5 mL of 12 mol / L hydrochloric acid and then sodium carbonate to adjust the pH to 7-8, potassium chloroplatinate aqueous solution (5 mL) was added, followed by 100 mL of 10 mmol L -1 The reaction was continued for 2 hours using an aqueous ascorbic acid solution as a reducing agent. The resulting mixed solution was cooled, filtered, and washed until the filtrate was neutral. The solution was then vacuum-dried at 70°C overnight and ground. The solution was then heat-treated at 200°C for 2 hours in a 5% hydrogen-argon atmosphere to obtain a supported low-Pt core-shell alloy.

[0059] Example 3

[0060] 20mg of Ketjen Black EC-300J was diluted with 0.2mgmL -1 The concentration of 50 μL of Brij 35 aqueous solution was dispersed in deionized water and ultrasonicated for 60 min. The mixture was then placed in a water bath with a speed of 800 rpm and a temperature of 25 ° C. First, 20 mmol L -1 A copper chloride aqueous solution (5 mL) and a sodium chloroaurate aqueous solution (5 mL) were added, and the ratio of Cu atoms to Au atoms to Pt atoms was controlled to be 1:1:1. Subsequently, 5 mL of sodium carbonate aqueous solution was added to adjust the pH to 7-8, and then a 37 wt.% formaldehyde aqueous solution was added as a reducing agent and the reaction was carried out for 4 hours. After first adding 2 mL of 12 mol / L hydrochloric acid and then sodium hydroxide to adjust the pH to 7-8, a chloroplatinic acid aqueous solution (5 mL) was added, and then a 37 wt.% formaldehyde aqueous solution was added as a reducing agent and the reaction was carried out for 2 hours. The final mixed solution was cooled, filtered, and washed until the filtrate was neutral; vacuum dried at 70 ° C overnight and ground, and heat treated at 250 ° C for 2 hours under a 5% hydrogen and argon atmosphere to finally obtain a supported low Pt core-shell alloy material.

[0061] Example 4

[0062] 20 mg of ECP-600JD was diluted to 0.2 mg mL -1 The concentration of 100 μL PVP aqueous solution was dispersed in deionized water, ultrasonicated for 30 min, and then the mixture was placed in a water bath, and the speed was controlled at 800 rpm and the temperature was 25 ° C. First, a concentration of 10 mmol L-1 A copper chloride aqueous solution (10 mL) and a sodium chloroaurate aqueous solution (3 mL) were added, and the ratio of Cu atoms to Au atoms to Pt atoms was controlled to 3:1:1. Subsequently, 10 mL of sodium hydroxide was added to adjust the pH to 7-8, and 80 microliters of a 20 mM formic acid aqueous solution was added as a reducing agent to react for 4 hours. After adjusting the pH to 7-8 by adding sodium hydroxide, a chloroplatinic acid aqueous solution (5 mL) was added, followed by 80 microliters of a 20 mM formic acid aqueous solution as a reducing agent and reacted for 2 hours. The final mixed solution was cooled, filtered, and washed until the filtrate was neutral; vacuum dried at 70 ° C overnight and ground, and heat treated at 350 ° C for 2 hours in a 5% hydrogen argon atmosphere to finally obtain a supported low Pt core-shell alloy material.

Claims

1. A method for preparing a supported low-Pt core-shell fuel cell catalyst, characterized in that: The steps include: (1) The carbon support is dispersed in a surfactant aqueous solution. Under stirring conditions at a temperature of 0-25 °C, a Cu metal salt aqueous solution and an Au metal salt aqueous solution are added, and the pH of the solution is adjusted to ≥7 with an alkaline solution. Then, a reducing agent aqueous solution is added, and the reaction is continued for 0.1-1.5 h. The pH of the solution is first adjusted to ≤7 with an acid, and then with an alkaline solution. The pH of the solution is then adjusted to ≥7 with an alkaline solution. Then, a Pt metal salt aqueous solution is added, and then a reducing agent aqueous solution is added, and the reaction is continued for 0.1-5 h. (2) filtering, washing, and drying the mixed solution obtained in step (1); placing the obtained material in a tubular furnace; introducing a certain gas and keeping the temperature at 100 to 400° C. for 1 to 3 hours; and finally obtaining a supported low-Pt core-shell fuel cell catalyst after cooling; In step (2), the gas is one or more of helium, argon, nitrogen, hydrogen, CO or low-carbon alkanes; The supported low-Pt core-shell fuel cell catalyst is a carbon-supported platinum-copper-gold alloy material, in which the loading of the platinum-copper-gold alloy is 10-60 wt%, and the atomic ratio of Au, Cu and Pt is 1:1:1-1:4:

9.

2. The preparation method according to claim 1, wherein The carbon support is dispersed in the surfactant aqueous solution at a concentration of 0.01-2 mg mL -1 ; The concentration of the surfactant aqueous solution is 10-100 mmol L -1 ; The concentration of the metal salt aqueous solution is 0.1~60 mmol L; The concentration of the reducing agent aqueous solution is 0.5~400 mmol L -1 ; The amount of the reducing agent added each time is 2 to 10 times the total amount of the Cu metal salt, the Au metal salt, and the Pt metal salt.

3. The preparation method according to claim 1, characterized in that The carbon support comprises at least one of carbon black material, fullerene, carbon nanotube, carbon nanotube aerogel, carbon aerogel material, metal organic framework pyrolytic carbon material, graphene, graphene aerogel, and carbon nanocage; The surfactant is at least one of anionic surfactant, cationic surfactant, amphoteric surfactant and nonionic surfactant.

4. The preparation method according to claim 3, wherein The carbon black material includes at least one of Vulcan XC-72, BP2000, Ketjen Black EC-300J, and ECP-600JD; The cationic surfactant is at least one of alkyltrimethylammonium chloride, alkyldimethylbenzylammonium chloride, and dialkyldimethylammonium chloride; the amphoteric surfactant is at least one of γ-(methacryloyloxy)propyltrimethoxysilane, bis-(3-triethoxysilylpropyl)amine, and bis-(trimethoxysilylpropyl)amine; and the nonionic surfactant is at least one of Tween 20, Triton X-100, polyethylene glycol, and Surfynol 485.

5. The preparation method according to claim 1, characterized in that The Pt metal salt includes one or a mixture of two or more of chloroplatinic acid, chloroplatinous acid, potassium chloroplatinate, potassium chloroplatinite, sodium chloroplatinate, sodium chloroplatinite, ammonium chloroplatinate, and ammonium chloroplatinite; The Cu metal salt includes one or a mixture of two or more of cupric chloride, cuprous chloride, cupric nitrate, copper sulfate, cuprous nitrate, cuprous sulfate, and copper acetate; The Au metal salt includes one or a mixture of two or more of chloroauric acid, sodium chloroaurate, ammonium tetrachloroaurate, potassium chloroaurate, and potassium gold citrate; The reducing agent is one or a mixture of two or more of sodium borohydride, potassium borohydride, magnesium borohydride, formaldehyde, formic acid, citric acid, glucose, sucrose, and ascorbic acid.

6. The preparation method according to claim 1, wherein In step (1), the mixture is aerated with inert gas for 5-30 minutes before the first addition of the reducing agent; The inert gas is one or more of helium, argon and nitrogen; The stirring speed is greater than 200 rpm.

7. The preparation method according to claim 1, characterized in that In step (2), the heating rate is 1 to 10°C / min.

8. The preparation method according to claim 1, characterized in that The reducing agent is one or a mixture of two or more of sodium borohydride, potassium borohydride, magnesium borohydride, formaldehyde, formic acid, citric acid, glucose, sucrose, and ascorbic acid; The acid is one or a mixture of two or more of hydrochloric acid, sulfuric acid, perchloric acid, nitric acid, oxalic acid, sulfurous acid, phosphoric acid, nitrous acid, carbonic acid, formic acid, lactic acid, benzoic acid, and acetic acid; The alkali in the alkaline solution is sodium hydroxide, potassium hydroxide, barium hydroxide, ammonia water or a mixture of two or more thereof.

9. The preparation method according to claim 1, wherein In step (1), an aqueous reducing agent solution is added, and after reacting for 0.1 to 1.5 hours, the pH of the solution is first adjusted to ≤ 7 with an acid, and then the pH of the solution is adjusted to ≥ 7 with an alkaline solution, and then an aqueous Pt metal salt solution is added, and then an aqueous reducing agent solution is added, and the reaction is continued for 0.1 to 5 hours; In step (2), the drying time is 1 to 24 hours, the drying temperature is 60 to 90°C, and the drying environment is vacuum.

10. The supported low-Pt core-shell fuel cell catalyst obtained by the preparation method according to any one of claims 1 to 9, characterized in that: The catalyst comprises low-Pt core-shell alloy particles and a catalyst carrier. The low-Pt core-shell alloy particles are loaded on the catalyst carrier, and the catalyst carrier is a carbon carrier.

11. Use of the catalyst according to claim 10, characterized in that Used in oxygen reduction reactions.

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