Platinum-carbon catalyst, its preparation method and application, and hydrogen fuel cell

Abstract

The present invention discloses a platinum-carbon catalyst, a preparation method thereof and an application thereof. The present invention also relates to a hydrogen fuel cell using the platinum-carbon catalyst. The platinum-carbon catalyst contains a carbonaceous carrier and metal platinum particles supported on the carbonaceous carrier. At least 80% of the metal platinum particles have a particle size in the range of 3-5 nm, and the initial voltage of the platinum-carbon catalyst for catalyzing CO electro-oxidation is lower than 0.8 V. According to the platinum-carbon catalyst of the present invention, the metal platinum particles have good dispersion on the carrier, the catalyst has highly uniform cluster platinum particles, and there is a strong interaction between the platinum particles and the carrier, thereby improving the activity and stability of the platinum-carbon catalyst.

Description

Technical Field

[0001] The present invention relates to a platinum-carbon catalyst, a preparation method and an application thereof, and also relates to a hydrogen fuel cell using the platinum-carbon catalyst. Background Art

[0002] In the past few decades, proton exchange membrane fuel cell technology has made great progress, and currently the longest mileage of fuel cell vehicles can reach 700 km. However, the commercialization of fuel cells is still in its infancy, and further development is still restricted by the following technical aspects: high cost, low life and limited energy density.

[0003] As is well known, the kinetics of the oxygen reduction reaction (ORR) at the cathode in a proton exchange membrane fuel cell is slow, and its exchange current density is at 10 -6 A / cm 2 , far less than the hydrogen oxidation exchange current density at the anode. The existence of polarization phenomenon makes the actual potential of the battery far lower than the theoretical value. And the most effective catalyst for the oxygen reduction reaction is noble metal platinum, and its cost accounts for about 40% of the total cost of the fuel cell. According to the latest requirements of the US Department of Energy for the life of fuel cells, the performance loss of vehicle batteries after 8000 hours of use should not exceed 10%, and the service life of buses is 10000 hours. After years of research, it has been found that the attenuation of the catalytic activity of the catalyst is one of the main reasons for the performance attenuation of fuel cells. Therefore, the research and development of high-performance and durable oxygen reduction reaction electrode catalysts is of great significance for accelerating the commercialization of fuel cells.

[0004] At present, there are many methods for preparing platinum-carbon catalysts, such as chemical reduction method, electrochemical reduction method, physical method, etc. Among them, the chemical reduction method has been studied more, and different reducing agents are used, including sodium dithionite, sodium bisulfite, sodium formate, sodium borohydride or potassium borohydride, hydrazine hydrate, formaldehyde, etc. Different synthesis methods and processes determine that the prepared catalysts have different activities and stabilities. However, these methods cannot well control the particle size of the active components of the catalyst, and it is difficult to obtain a supported metal catalyst with good structural dispersion and small particle size.

[0005] Therefore, there is an urgent need to develop a platinum-carbon catalyst with good dispersion, small and uniform particle size of noble metals and its preparation technology. Summary of the Invention

[0006] The object of the present invention is to provide a platinum-carbon catalyst in which the dispersion of metallic platinum is good, having highly uniform cluster particles, and having a strong interaction between the particles and the carrier, showing improved activity and stability in the electrochemical oxygen reduction reaction.

[0007] According to a first aspect of the present invention, there is provided a platinum-carbon catalyst, which comprises a carbonaceous carrier and metal platinum particles supported on the carbonaceous carrier. Among them, in this platinum-carbon catalyst, at least 80% of the metal platinum particles have a particle size in the range of 3-5 nm, and the onset voltage of the platinum-carbon catalyst for catalyzing CO electro-oxidation is lower than 0.8V.

[0008] According to a second aspect of the present invention, there is provided a method for preparing a platinum-carbon catalyst, which comprises the following steps:

[0009] Step S1: Soak a carbon-based raw material with an organic solvent to obtain a first carbon-based material, and the organic solvent is a ketone solvent;

[0010] Step S2: Contact the first carbon-based material with an oxidant to obtain a second carbon-based material, and the oxidant is one or more selected from peroxides;

[0011] Step S3: Contact the second carbon-based material with nitric acid to obtain a third carbon-based material;

[0012] Step S4: Calcinate the third carbon-based material in an inert atmosphere to obtain a carbonaceous carrier, and the temperature of the calcination is 300-600°C;

[0013] Step S5: Ultrasonically disperse the carbonaceous carrier, a platinum precursor and a complexing agent in a coupling solvent to obtain a first dispersion. The coupling solvent is a first coupling solvent or a second coupling solvent. The first coupling solvent contains water and at least one C2-C8 polyol, and the second coupling solvent contains at least two C2-C8 polyols. Among them, the molar concentration of the platinum precursor is C0, and the molar concentration of platinum in the liquid phase of the first dispersion obtained in step S5 is C1, and C1 / C0 < 0.2;

[0014] Step S6: Add a pH regulator to the first dispersion to adjust the pH value of the first dispersion to be alkaline to obtain a second dispersion;

[0015] Step S7: In an inert atmosphere, contact the aqueous dispersion with a reducing agent to reduce at least part of the platinum precursor to metallic platinum, and at least part of the reducing agent is formic acid.

[0016] According to a third aspect of the present invention, there is provided a platinum-carbon catalyst prepared by the method described in the second aspect of the present invention.

[0017] According to a fourth aspect of the present invention, there is provided a hydrogen fuel cell, and the anode and / or cathode of the hydrogen fuel cell contains the platinum-carbon catalyst described in the first aspect or the fourth aspect of the present invention.

[0018] For the platinum-carbon catalyst according to the present invention, the metal platinum particles have good dispersibility on the carrier, the catalyst has highly uniform platinum particle clusters, and there is a strong electronic interaction between the platinum particles and the carrier, thereby effectively improving the activity and stability of the platinum-carbon catalyst.

[0019] The preparation method of the platinum-carbon catalyst according to the present invention is applicable to the preparation of catalysts with various platinum loadings. The method of the present invention is easy to scale up and has good prospects for large-scale production. Description of the Drawings

[0020] Figure 1A TEM photograph of the platinum-carbon catalyst prepared in Example 1, Figure 1B used to illustrate the particle size distribution of the metal platinum particles in the platinum-carbon catalyst prepared in Example 1.

[0021] Figure 2 AC-STEM photograph of the platinum-carbon catalyst prepared in Example 1.

[0022] Figure 3 CO electrooxidation reaction performance curve of the platinum-carbon catalyst prepared in Example 1.

[0023] Figure 4 TEM photograph of the platinum-carbon catalyst prepared in Comparative Example 1.

[0024] Figure 5 ORR polarization curves of the platinum-carbon catalysts prepared in Example 1 and Comparative Example 1.

[0025] Figure 6 ORR polarization curve of the platinum-carbon catalyst prepared in Example 6.

[0026] Figure 7 ORR polarization curve of the platinum-carbon catalyst prepared in Example 7.

[0027] Figure 8 ORR polarization curve of the platinum-carbon catalyst prepared in Example 8.

[0028] Figure 9 ORR polarization curve of the platinum-carbon catalyst prepared in Example 9. Detailed Description of the Invention

[0029] The endpoints and any values disclosed herein are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0030] According to the first aspect of the present invention, the present invention provides a platinum-carbon catalyst, which comprises a carbonaceous carrier and metal platinum particles supported on the carbonaceous carrier.

[0031] In the platinum-carbon catalyst according to the present invention, at least 80% of the metal platinum particles have a particle size in the range of 3-5 nm. Preferably, in the platinum-carbon catalyst, 80-85% of the metal platinum particles have a particle size in the range of 3-5 nm.

[0032] In the present invention, the particle size of the metal platinum particles in the platinum-carbon catalyst is measured by transmission electron microscopy.

[0033] In the platinum-carbon catalyst according to the present invention, the starting voltage for the electrooxidation of CO catalyzed by the platinum-carbon catalyst is lower than 0.8 V, generally 0.75-0.79 V.

[0034] In the present invention, the starting voltage for the electrooxidation of CO catalyzed by the platinum-carbon catalyst is measured by electrochemical cyclic voltammetry. The specific test method is as follows: 1) Using a disk electrode coated with the platinum-carbon catalyst as the working electrode, a graphite rod as the counter electrode, and a saturated calomel electrode as the reference electrode, first bubble high-purity CO into a 0.1 M HClO4 solution until saturated; 2) Then switch to bubbling high-purity N2 for 5-10 minutes to desorb the physically adsorbed CO from the catalyst surface; 3) Perform electrochemical cyclic voltammetry tests in the voltage range of 0.05-1.5 V, with a scan rate of 50 mV / s, continuously scan 2 cycles, and take the peak starting potential of the first cycle as the starting potential for the electrooxidation of CO.

[0035] In the platinum-carbon catalyst according to the present invention, based on the total amount of the platinum-carbon catalyst, the content of the platinum element is 40-80% by weight, and the content of the carbonaceous carrier is 20-60% by weight, with the carbonaceous carrier calculated as carbon element. Preferably, based on the total amount of the platinum-carbon catalyst, the content of the platinum element is 60-70% by weight, and the content of the carbonaceous carrier is 30-40% by weight, with the carbonaceous carrier calculated as carbon element.

[0036] In the present invention, the contents of the platinum element and the carbonaceous carrier in the platinum-carbon catalyst are measured by inductively coupled plasma spectroscopy (ICP).

[0037] In the platinum-carbon catalyst according to the present invention, the carbonaceous carrier is conductive carbon black. Preferred examples of the conductive carbon black may include, but are not limited to, one or more of Vulcan XC-72R, Ketjen EC-300J, Ketjen EC-600J, Blackpearls2000, and Blackpearls 3000. In the platinum-carbon catalyst according to the present invention, the specific surface area of the carbonaceous carrier is preferably 200-2000 m2 / g, more preferably 250 - 1500 m 2 / g. In the present invention, the specific surface area is measured by the method of specific surface area and pore size analyzer (BET).

[0038] According to the second aspect of the present invention, the present invention provides a method for preparing a platinum-carbon catalyst, which method comprises the following steps:

[0039] Step S1: Soak the carbon-based raw material with an organic solvent to obtain a first carbon-based material, and the organic solvent is a ketone solvent;

[0040] Step S2: Contact the first carbon-based material with an oxidant to obtain a second carbon-based material, and the oxidant is one or more selected from peroxides;

[0041] Step S3: Contact the second carbon-based material with nitric acid to obtain a third carbon-based material;

[0042] Step S4: Calcinate the third carbon-based material in an inert atmosphere to obtain a carbonaceous support, and the calcination temperature is 300 - 600 °C;

[0043] Step S5: Ultrasonically disperse the carbonaceous support, platinum precursor and complexing agent in a coupling solvent to obtain a first dispersion, and the coupling solvent is a first coupling solvent or a second coupling solvent. The first coupling solvent contains water and at least one C2 - C8 polyol, and the second coupling solvent contains at least two C2 - C8 polyols. Among them, the molar concentration of the platinum precursor is C0, C0 = m Pt / V 分散介质 wherein, m Pt is the amount of substance of the platinum precursor in moles, V 分散介质 is the volume of the dispersion medium in liters. The molar concentration of platinum in the liquid phase of the first dispersion obtained in step S5 is C1, and C1 / C0 < 0.2;

[0044] Step S6: Add a pH regulator to the first dispersion to adjust the pH value of the first dispersion to alkaline to obtain a second dispersion;

[0045] Step S7: In an inert atmosphere, contact the aqueous dispersion with a reducing agent to reduce at least part of the platinum precursor to metallic platinum, and at least part of the reducing agent is formic acid.

[0046] In step S1, the carbon-based raw material is conductive carbon black. Preferred examples of the conductive carbon black may include, but are not limited to, one or more of Vulcan XC-72R, Ketjen EC-300J, Ketjen EC-600J, Blackpearls2000, and Blackpearls3000. For the platinum-carbon catalyst according to the present invention, the specific surface area of the carbonaceous carrier is preferably 200-2000 m 2 / g, more preferably 250-1500 m 2 / g.

[0047] In step S1, the organic solvent is one or more selected from ketone solvents, preferably acetone. The soaking can be carried out at room temperature or under the condition of elevated temperature. Preferably, the temperature of the organic solvent is 50-70 °C. The soaking duration can be selected according to the soaking temperature. Generally, the soaking duration can be 5-12 hours, such as 8-12 hours. The amount of the organic solvent is such that the carbon-based raw material can be submerged. Generally, the volume ratio of the organic solvent to the carbon-based raw material can be 1-3:1.

[0048] In step S2, the oxidant is one or more selected from peroxides. Preferably, the oxidant is one or more selected from hydrogen peroxide and the organic peroxide shown in formula (I):

[0049]

[0050] In formula I, R1 and R2 each independently selected from H, C4-C 12 alkyl, C6-C 12 aryl, C7-C 12 aralkyl, and and R1 and R2 are not both H at the same time, and R3 is a straight-chain or branched-chain alkyl group of C4-C 12 or an aryl group of C6-C 12 ).

[0051] In the present invention, specific examples of the C4-C 12 alkyl may include, but are not limited to, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl, isopentyl, tert-pentyl, hexyl (including various isomers of hexyl), cyclohexyl, octyl (including various isomers of octyl), nonyl (including various isomers of nonyl), decyl (including various isomers of decyl), undecyl (including various isomers of undecyl), and dodecyl (including various isomers of dodecyl).

[0052] In the present invention, C6-C 12Specific examples of the aryl group may include, but are not limited to, phenyl, naphthyl, methylphenyl, and ethylphenyl.

[0053] In the present invention, C7-C 12 Specific examples of the aralkyl group may include, but are not limited to, phenylmethyl, phenylethyl, phenyl-n-propyl, phenyl-n-butyl, phenyl-t-butyl, phenyl-isopropyl, phenyl-n-pentyl, and phenyl-n-butyl.

[0054] Specific examples of the organic peroxide may include, but are not limited to: tert-butyl hydroperoxide, cumene hydroperoxide, ethylbenzene hydroperoxide, cyclohexyl hydroperoxide, dicumyl peroxide, benzoyl peroxide, di-tert-butyl peroxide, and lauroyl peroxide.

[0055] Preferably, in step S2, the oxidizing agent is hydrogen peroxide.

[0056] In step S2, in the presence of a liquid dispersion medium, the first carbon-based material is brought into contact with the oxidizing agent in the liquid phase. The liquid dispersion medium may be water and / or an alcohol having 1 to 4 carbon atoms, preferably water. In a preferred embodiment, the oxidizing agent is dissolved in the liquid dispersion medium to form an oxidizing agent solution, and the oxidizing agent solution is brought into contact with the first carbon-based material. In this preferred embodiment, hydrogen peroxide solution is preferably used as the oxidizing agent solution. The concentration of hydrogen peroxide in the hydrogen peroxide solution may be 10-40% by weight, preferably 20-30% by weight.

[0057] In step S2, the contact is preferably carried out at a temperature of 50-70 °C, for example, at a temperature of 55-65 °C. The duration of the contact can be selected according to the temperature of the contact, preferably 5-12 hours, for example, 8-12 hours. The amount of the oxidizing agent can be selected according to the amount of the first carbon-based material. Preferably, the mass ratio of the oxidizing agent to the first carbon-based material is 1-3:1.

[0058] In step S3, the mass ratio of nitric acid to the second carbon-based material is 1-3:1, and the nitric acid is calculated as HNO3. The concentration of nitric acid may be 10-60% by weight, preferably 20-50% by weight, more preferably 30-45% by weight. In step S3, the contact is preferably carried out at a temperature of 50-70 °C, for example, at a temperature of 55-65 °C. In step S3, the duration of the contact can be selected according to the temperature of the contact. Preferably, the duration of the contact can be 5-12 hours, for example, 8-12 hours.

[0059] In step S4, the third carbon-based material is calcined in an inert atmosphere at a temperature of 300-600 °C to obtain a carbonaceous support. Preferably, the calcination is carried out at a temperature of 300-400 °C. The inert atmosphere can be an atmosphere formed by nitrogen and / or noble gases, for example: an atmosphere formed by one or more of nitrogen, argon, and helium, preferably a nitrogen atmosphere. The duration of the calcination can be selected according to the calcination temperature. Preferably, the duration of the calcination is 5-12 hours. More preferably, the duration of the calcination is 6-8 hours.

[0060] According to the preparation method of the present invention, compared with directly using a carbonaceous raw material as a carrier to prepare a platinum-carbon catalyst, the performance of the platinum-carbon catalyst prepared using the carbonaceous support obtained in step S4 as a carrier is significantly improved, especially the stability is significantly improved.

[0061] In step S5, the carbonaceous support, a platinum precursor, and a complexing agent are ultrasonically dispersed in a coupling solvent to obtain a first dispersion.

[0062] In step S5, the platinum precursor can be a platinum-containing compound that can be reduced to metallic platinum by a reducing agent under reduction reaction conditions. According to the method of the present invention, the platinum precursor can be one or more of chloroplatinic acid, potassium chloroplatinate, and sodium chloroplatinate. Preferably, the platinum precursor is chloroplatinic acid.

[0063] In step S5, the amount of the platinum precursor can be selected according to the expected platinum content in the platinum-carbon catalyst. Generally, the amount of the platinum precursor is such that in the finally prepared platinum-carbon catalyst, based on the total amount of the platinum-carbon catalyst, the content of platinum element is 40-80 wt%, and the content of the carbonaceous support is 20-60 wt%, with the carbonaceous support calculated as carbon element. Preferably, the amount of the platinum precursor is such that in the finally prepared platinum-carbon catalyst, based on the total amount of the platinum-carbon catalyst, the content of platinum element is 60-70 wt%, and the content of the carbonaceous support is 30-40 wt%, with the carbonaceous support calculated as carbon element. Preferably, in step S5, the mass ratio of the platinum precursor to the carbonaceous support is 1.5-10:1. More preferably, in step S5, the mass ratio of the platinum precursor to the carbonaceous support is 3-8:1. Further preferably, in step S5, the mass ratio of the platinum precursor to the carbonaceous support is 4-6:1.

[0064] In step S5, the complexing agent is one or more of water-soluble salts of dicarboxylic acids and water-soluble salts of polycarboxylic acids. For example, it can be one or more of alkali metal salts of dicarboxylic acids, ammonium salts of dicarboxylic acids, alkali metal salts of polycarboxylic acids, and ammonium salts of polycarboxylic acids. The polycarboxylic acid refers to an organic compound containing three or more carboxyl groups in its molecular structure. In a preferred embodiment, the complexing agent is one or more of citric acid, sodium citrate, sodium oxalate, sodium ethylenediaminetetraacetate, and sodium tartrate, preferably citric acid and / or sodium citrate. In step S5, the mass ratio of the platinum precursor to the complexing agent is preferably 1:0.1 - 7, more preferably 1:0.2 - 3, further preferably 1:0.3 - 2, still further preferably 1:0.4 - 1, and particularly preferably 1:0.5 - 0.6.

[0065] In step S5, the coupling solvent is the first coupling solvent or the second coupling solvent. The first coupling solvent contains water and at least one C2 - C8 polyol. The second coupling solvent contains at least two C2 - C8 polyols. In the present invention, the term "polyol" refers to an alcohol containing two or more hydroxyl groups (-OH) in its molecular structure. Specific examples of C2 - C8 polyols in the present invention may include, but are not limited to, one or more of ethylene glycol, 1,2 - propanediol, 1,3 - propanediol, glycerol, and 1,2 - pentanediol.

[0066] In a preferred embodiment, the coupling solvent is the first coupling solvent, which contains water and at least one C2 - C8 polyol. More preferably, the first coupling solvent is water and at least one triol. Further preferably, the first coupling solvent is water and glycerol. In the first coupling solvent, the volume ratio of water to the polyol is preferably 1:1 - 5, more preferably 1:1 - 3.

[0067] In another preferred embodiment, the coupling solvent is the second coupling solvent, which contains at least one diol and at least one triol. The diol is preferably one or more of ethylene glycol, 1,2 - propanediol, 1,3 - propanediol, and 1,2 - pentanediol, more preferably one or more of 1,2 - propanediol, 1,3 - propanediol, and 1,2 - pentanediol. The triol is preferably glycerol. In the second coupling solvent, the volume ratio of the diol to the triol is 1:1 - 5.

[0068] Compared with using water alone as a solvent or using a polyol alone as a solvent to prepare the first dispersion, the method according to the present invention uses the coupling solvent, and even at a higher platinum loading, the metal platinum particles in the prepared platinum-carbon catalyst have a higher structural dispersibility, which may be due to the use of the coupling solvent to effectively change the polarity of the reduction reaction system solution, thereby improving the dispersibility of the metal platinum particles. According to the method of the present invention, the coupling solvent is particularly preferably the first coupling solvent.

[0069] In step S5, the amount of the coupling solvent can be selected according to the amount of the platinum precursor and the carbonaceous carrier. Preferably, in step S5, the amount of the platinum precursor relative to the coupling solvent is 1-20 g / L. More preferably, in step S5, the amount of the platinum precursor relative to the coupling solvent is 2-10 g / L. Further preferably, in step S5, the amount of the platinum precursor relative to the coupling solvent is 3-6 g / L.

[0070] According to the method of the present invention, in step S5, the carbonaceous carrier, the platinum precursor and the complexing agent are dispersed in a coupling solvent by ultrasound, and the carbonaceous carrier and the platinum precursor are fully mixed. The power of the ultrasound is preferably 100-1000W, more preferably 200-800W, and further preferably 300-600W. The duration of the ultrasonic dispersion can be 0.2-0.5 hours. The present invention does not specifically limit the device used for ultrasonic dispersion, and dispersion can be carried out in a common ultrasonic dispersion device.

[0071] According to the method of the present invention, in the first dispersion formed in step S5, the platinum content in the liquid phase of the first dispersion is low, and the adhesion rate of the platinum precursor on the carbonaceous material is high. According to the method of the present invention, the molar concentration of the platinum precursor is C0, C0=m Pt / V 分散介质 , where m Pt is the amount of the platinum precursor in moles, V 分散介质 is the volume of the dispersion medium, in liters, the molar concentration of platinum in the liquid phase of the first dispersion obtained in step S5 is C1, C1 / C0<20%. Preferably, C1 / C0<0.16. More preferably, C1 / C0 is 0.05-0.15.

[0072] In the present invention, the method for determining the molar concentration (C1) of platinum in the liquid phase of the first dispersion is as follows: 20 mL of the first dispersion is centrifuged in a high-speed centrifuge at a speed of not less than 5000 rpm for 10 minutes, 10 mL of the supernatant after centrifugation is taken as a sample, and the platinum content therein is determined by inductively coupled plasma emission spectrometry (ICP method), and then the molar concentration (C1) of platinum in the liquid phase of the first dispersion is calculated.

[0073] According to the method of the present invention, in step S6, a pH regulator is added to the first dispersion to adjust the pH value of the first dispersion to be alkaline, obtaining a second dispersion. Preferably, the pH value of the aqueous phase is adjusted to 8-14, more preferably to 10-13, and further preferably to 11-13. The pH regulator is preferably one or more of sodium carbonate, potassium carbonate, ammonia water, potassium hydroxide, and sodium hydroxide. The pH regulator is preferably provided in the form of an aqueous solution, and the concentration of the aqueous solution can be a conventional selection without special limitation.

[0074] According to the method of the present invention, in step S7, in an inert atmosphere, the second dispersion is contacted with a reducing agent to reduce at least part of the platinum precursor to metallic platinum.

[0075] In step S7, at least part of the reducing agent is formic acid. In step S7, the reducing agent can be formic acid. In a preferred embodiment, the reducing agent is ascorbic acid and formic acid. In this preferred embodiment, the molar ratio of ascorbic acid to formic acid is preferably 1:0.5-10, more preferably 1:0.8-8, further preferably 1:1-6, and particularly preferably 1:1.2-5.

[0076] According to the method of the present invention, in step S7, the molar ratio of the reducing agent to the platinum precursor is preferably 5-1000:1, more preferably 10-500:1, further preferably 100-400:1, still further preferably 150-300:1, and particularly preferably 180-220:1, with the platinum precursor calculated in terms of platinum element. In step S7, the reducing agent is used in an amount exceeding the stoichiometric ratio. While reducing the platinum precursor to metallic platinum, the pH of the reaction system is also adjusted to be acidic, such that the platinum precursor and the reducing agent react under acidic conditions.

[0077] In step S7, the reducing agent is contacted with the second aqueous dispersion at 50-140 °C, preferably at 60-120 °C, more preferably at 70-100 °C, and further preferably at 75-85 °C. In step S7, the duration of the reduction reaction can be selected according to the temperature at which the reduction reaction is carried out. Preferably, in step S7, the duration of contact between the second aqueous dispersion and the reducing agent is 4-12 hours. More preferably, in step S7, the duration of contact between the second aqueous dispersion and the reducing agent is 6-10 hours. In step S7, the reduction reaction is carried out in an inert atmosphere, for example, it can be carried out in an atmosphere of nitrogen and / or noble gas (such as argon and / or helium).

[0078] According to the method of the present invention, the solid-phase substance can be separated from the reduction mixture obtained in step S7 by a conventional separation method, and the separated solid-phase substance is washed and dried in sequence to obtain the platinum-carbon catalyst according to the present invention. Generally, the reduction mixture obtained in step S7 can be subjected to solid-liquid separation by one or a combination of two or more of filtration, centrifugation, and sedimentation to obtain the solid-phase substance. The drying is preferably carried out at a temperature of 60-120 °C, more preferably at a temperature of 80-110 °C. The duration of the drying can be 5-24 hours, preferably 6-12 hours. The drying can be carried out under normal pressure or under conditions of lower than atmospheric pressure.

[0079] The platinum-carbon catalyst prepared by the method of the present invention shows improved electrochemically active and stability.

[0080] According to the third aspect of the present invention, the present invention provides a platinum-carbon catalyst prepared by the method described in the second aspect of the present invention.

[0081] For the platinum-carbon catalyst according to the third aspect of the present invention, in this platinum-carbon catalyst, at least 80% of the metal platinum particles have a particle size in the range of 3-5 nm. Preferably, in this platinum-carbon catalyst, 80-85% of the metal platinum particles have a particle size in the range of 3-5 nm. For the platinum-carbon catalyst according to the third aspect of the present invention, the initial voltage of this platinum-carbon catalyst for catalyzing CO electro-oxidation is lower than 0.8 V, generally 0.75-0.79 V.

[0082] The platinum-carbon catalyst according to the present invention is particularly suitable for fuel cells. According to the fourth aspect of the present invention, the present invention provides the application of the platinum-carbon catalyst described in the first aspect or the third aspect of the present invention in fuel cells.

[0083] According to the fifth aspect of the present invention, the present invention provides a hydrogen fuel cell, and the anode and / or cathode of this hydrogen fuel cell contains the platinum-carbon catalyst described in the first aspect or the third aspect of the present invention.

[0084] The present invention will be described in detail below in conjunction with examples, but this does not limit the scope of the present invention.

[0085] In the following examples and comparative examples, transmission electron microscopy analysis was carried out on a transmission electron microscope of model JEM-2100 purchased from JEOL Ltd. Aberration-corrected scanning transmission electron microscopy (hereinafter simply referred to as aberration electron microscopy) analysis was carried out on a scanning transmission electron microscope of model JEM-ARM300F purchased from JEOL Ltd.

[0086] In the following examples and comparative examples, the test method for the molar concentration of platinum in the liquid phase of the first dispersion formed after ultrasonic dispersion is as follows: Take 20 mL of the first dispersion and centrifuge it in a high-speed centrifuge at a speed of not less than 5000 rpm for 10 minutes. Then, aspirate 10 mL of the supernatant after centrifugation as a sample, and use inductively coupled plasma emission spectrometry (ICP method) to measure the platinum content therein, and then calculate the molar concentration (C1) of platinum in the liquid phase of the first dispersion.

[0087] In the following examples and comparative examples, the composition of the platinum-carbon catalyst was determined by inductively coupled plasma emission spectrometry (ICP method).

[0088] In the following examples and comparative examples, the particle size of platinum in the platinum-carbon catalyst was determined by transmission electron microscopy. The specific test method was as follows: Randomly select 8 non-overlapping and well-dispersed transmission electron microscopy images of catalyst particles on the sample to be tested. For each image, select 50 (a total of 400 for 8 images) catalyst platinum particle diameters for statistics. Finally, take the average particle diameter and draw a particle size distribution diagram.

[0089] In the following examples and comparative examples, the test method for the starting voltage of the platinum-carbon catalyst for CO electrooxidation is as follows: 1) Use the disk electrode coated with the platinum-carbon catalyst as the working electrode, the graphite rod as the counter electrode, and the saturated calomel electrode as the reference electrode. First, bubble high-purity CO into the 0.1 M HClO4 solution until saturated; 2) Then switch to bubbling high-purity N2 for 5 - 10 minutes to desorb the physically adsorbed CO from the catalyst surface; 3) Perform electrochemical cyclic voltammetry tests in the voltage range of 0.05 - 1.5 V at a scan rate of 50 mV / s, and continuously scan 2 cycles. Take the peak starting potential of the first cycle as the starting potential of CO electrooxidation.

[0090] In the following examples and comparative examples, the test method for the electrochemical activity of the platinum-carbon catalyst was carried out by electrochemical voltammetry using a rotating disk electrode (RDE):

[0091] (1) The three-electrode system is a glassy carbon working electrode coated with the catalyst, a graphite counter electrode, and a saturated calomel reference electrode. The manufacturing method of the working electrode:

[0092] Prepare a 1 mg / mL slurry of the platinum-carbon catalyst and ethanol, ultrasonically disperse it for more than 30 min, take 0.01 mL of the slurry and evenly coat it on the surface of the glassy carbon electrode, and dry it naturally to obtain the working electrode.

[0093] (2) Test conditions

[0094] The test conditions for the electrochemically active surface area (ECSA) are as follows: 0.1 M HClO4 solution, the scanning range is 0.05 - 1.2 V, the scanning rate is 50 mV / s, and it is saturated with nitrogen;

[0095] The polarization curve test conditions are as follows: 0.1M HClO4 solution, the scanning range is 0.6 - 1.0V, the scanning rate is 10mV / s, saturated with oxygen, and the rotation speed of the rotating disk electrode is 1600r / min.

[0096] (3) Calculation method of performance parameters

[0097] The electrochemically active surface area (ECSA), half-wave potential (E 1 / 2 ), diffusion current density (J L ) can be directly read from the test software or the polarization curve;

[0098] The kinetic current density (J K ) is calculated according to the apparent current density (J 0.9V ) corresponding to 0.9V on the polarization curve and the diffusion current density (J L ) according to the formula 1 / J 0.9V = 1 / J K + 1 / J L ;

[0099] The specific activity is calculated by dividing J K by the mass per unit area of platinum on the electrode (m Pt ), and the intrinsic activity is obtained by dividing the specific activity by ECSA.

[0100] The following conductive carbon blacks are involved in the following examples and comparative examples:

[0101] (1) Conductive carbon black with the brand name Ketjen EC-600J, purchased from Lion Corporation of Japan, with a particle diameter in the range of 50 - 100nm and a specific surface area of 1500m 2 / g.

[0102] (2) Conductive carbon black with the brand name Vulcan XC-72R, purchased from Cabot Corporation of the United States, with a particle diameter in the range of 50 - 100nm and a specific surface area of 260m 2 / g.

[0103] Examples 1 - 10 are used to illustrate the platinum-carbon catalyst of the present invention, its preparation method and application.

[0104] Example 1

[0105] (1) Immerse Ketjen EC-600J conductive carbon black in acetone (analytical pure) at a temperature of 60°C for 8h, where the mass ratio of acetone to conductive carbon black is 2:1. After immersion, perform suction filtration to obtain a solid substance, and dry the solid substance at 100°C for 8h to obtain the conductive carbon black soaked in acetone.

[0106] (2) Soak the acetone-soaked conductive carbon black in a 20% hydrogen peroxide solution (the mass ratio of hydrogen peroxide to conductive carbon black is 2:1), and react at 60 °C for 12 h. After the reaction is completed, filter the reaction mixture by suction, and dry the obtained solid phase material at 100 °C for 8 h to obtain the first-oxidized conductive carbon black.

[0107] (3) Mix the first-oxidized conductive carbon black with a 30% nitric acid aqueous solution (the mass ratio of HNO3 to conductive carbon black is 2:1), and react at 60 °C for 12 h. After the reaction is completed, filter the reaction mixture by suction, and dry the obtained solid phase material at 100 °C for 8 h to obtain the second-oxidized conductive carbon black.

[0108] (4) Roast the second-oxidized conductive carbon black in a nitrogen atmosphere at 300 °C for 8 h to obtain the pre-treated conductive carbon black.

[0109] (5) Add 0.3 g of the pre-treated conductive carbon black to a mixed solution of 400 mL of deionized water and glycerol (the volume ratio of water to glycerol is 1:1). After mixing evenly, add 1 g of sodium citrate, and then add an aqueous solution of chloroplatinic acid (chloroplatinic acid is 3.6 mmol). Ultrasonically disperse the obtained mixture to form a first dispersion. Among them, the power of the ultrasonic wave is 500 W, and the ultrasonic dispersion time is 0.5 h. Take a sample from the first dispersion, analyze the content of platinum in the liquid phase of the first dispersion, and further calculate that C1 / C0 is 0.082 (where C0 is determined by the feed ratio, the same below).

[0110] (6) Add an aqueous solution of sodium carbonate to the first dispersion obtained by ultrasonic treatment, and adjust the pH value of the first dispersion to 13 to obtain a second dispersion.

[0111] (7) Heat the second dispersion to 80 °C with a heater, and add a reducing agent for a reduction reaction while stirring. Among them, the molar ratio of the reducing agent to chloroplatinic acid is 200:1. The reducing agent is a mixture of formic acid and ascorbic acid, where the addition amount of formic acid is 0.58 mol and the addition amount of ascorbic acid is 0.14 mol. After the addition of the reducing agent is completed, keep the heating conditions of the heater unchanged and continue the reaction for 10 h.

[0112] After the reaction is completed, filter the reduction reaction mixture, collect the solid phase material, and wash the solid phase material with deionized water until the pH value of the filtrate is neutral. Vacuum-dry the washed solid phase material at 100 °C for 8 h. Grind the dried solid phase material to obtain 1 g of platinum-carbon catalyst. After measurement, the mass content of platinum in this platinum-carbon catalyst is 70% by weight, denoted as Pt / C-70%-1. The RDE test results of this catalyst are listed in Table 1.

[0113] Figure 1A TEM image of the Pt / C catalyst prepared in Example 1. It can be seen that Figure 1A in the Pt / C catalyst prepared in Example 1, the metal Pt particles are evenly dispersed with uniform size and no obvious agglomeration, indicating good structural dispersion of Pt particles on the carbonaceous support. It can be seen that Figure 1B in the Pt / C catalyst prepared in Example 1, 82% of the metal Pt particles have a particle size in the range of 3 - 5 nm. Figure 2 AC-STEM image of the Pt / C catalyst prepared in Example 1. It can be seen that Figure 2 the Pt / C catalyst prepared in Example 1 has highly uniform cluster particles. Figure 3 CO electro-oxidation characterization reaction results of the Pt / C catalyst prepared in Example 1. It can be seen that Figure 3 the onset potential of CO electro-oxidation of the Pt / C catalyst prepared in Example 1 is lower than 0.8 V, being 0.77 V (the onset potential of CO electro-oxidation of commercial Pt / C catalysts is generally above 0.8 V), indicating that the support modifies the electronic structure of Pt and there is a strong interaction between the metal Pt particles and the support.

[0114] Comparative Example 1

[0115] A Pt / C catalyst was prepared using the same method as in Example 1, except that in step (5), sodium citrate was not used, and glycerol was not used as the dispersion medium. Instead, 400 mL of deionized water was directly used as the dispersion medium to prepare the first dispersion liquid (samples were taken from the first dispersion liquid to analyze the content of Pt in the liquid phase of the first dispersion liquid, and further calculate C1 / C0 to be 0.318). The prepared Pt / C catalyst is denoted as Pt / C-70%-R, and the RDE test results of this catalyst are listed in Table 1.

[0116] Figure 4 TEM image of the Pt / C catalyst prepared in Comparative Example 1. In the Pt / C catalyst prepared in Comparative Example 1, the metal Pt particles are larger in size and have obvious agglomeration. After statistical analysis, it is determined that the proportion of metal Pt particles with a particle size in the range of 3 - 5 nm is 30%. The onset potential of CO electro-oxidation of this Pt / C catalyst is 0.83 V.

[0117] Figure 5 ORR polarization curves of the Pt / C catalysts prepared in Example 1 and Comparative Example 1 measured by RDE in an oxygen-saturated 0.1 M HClO4 electrolyte.

[0118] Comparative Example 2

[0119] The platinum-carbon catalyst was prepared by the same method as in Example 1, except that in step (5), sodium citrate was not used (sampling from the first dispersion, analyzing the content of platinum in the liquid phase of the first dispersion, and further calculating C1 / C0 to be 0.295), thereby obtaining the platinum-carbon catalyst. The RDE test results of this catalyst are listed in Table 1. In this platinum-carbon catalyst, the proportion of metallic platinum particles with a particle size in the range of 3 - 5 nm is 35%. The starting potential of CO electro-oxidation of this platinum-carbon catalyst is 0.83 V.

[0120] Comparative Example 3

[0121] The platinum-carbon catalyst was prepared by the same method as in Example 1, except that in step (5), instead of using glycerol as the dispersion medium, 400 mL of deionized water was directly used as the dispersion medium to prepare the first dispersion (sampling from the first dispersion, analyzing the content of platinum in the liquid phase of the first dispersion, and further calculating C1 / C0 to be 0.268), thereby obtaining the platinum-carbon catalyst. The RDE test results of this catalyst are listed in Table 1. In this platinum-carbon catalyst, the proportion of metallic platinum particles with a particle size in the range of 3 - 5 nm is 50%. The starting potential of CO electro-oxidation of this platinum-carbon catalyst is 0.82 V.

[0122] Comparative Example 4

[0123] The platinum-carbon catalyst was prepared by the same method as in Example 1, except that steps (1) to (4) were not carried out, but instead, the KetjenEC-600J conductive carbon black used as a raw material in step (1) of Example 1 was directly used in step (5) to prepare the first dispersion (sampling from the first dispersion, analyzing the content of platinum in the liquid phase of the first dispersion, and further calculating C1 / C0 to be 0.215), and finally, the platinum-carbon catalyst was prepared. The RDE test results of this catalyst are listed in Table 1. In this platinum-carbon catalyst, the proportion of metallic platinum particles with a particle size in the range of 3 - 5 nm is 67%. The starting potential of CO electro-oxidation of this platinum-carbon catalyst is 0.81 V.

[0124] Example 2

[0125] The platinum-carbon catalyst was prepared by the same method as in Example 1, except that in step (7), while keeping the molar ratio of formic acid to ascorbic acid unchanged, the molar ratio of the reducing agent to chloroplatinic acid was adjusted to 100:1, thereby obtaining the platinum-carbon catalyst. The RDE test results of this catalyst are listed in Table 1. In this platinum-carbon catalyst, the proportion of metallic platinum particles with a particle size in the range of 3 - 5 nm is 85%. The starting potential of CO electro-oxidation of this platinum-carbon catalyst is 0.78 V.

[0126] Example 3

[0127] The platinum-carbon catalyst was prepared using the same method as in Example 1, except that in step (7), while keeping the molar ratio of formic acid to ascorbic acid unchanged, the molar ratio of the reducing agent to chloroplatinic acid was adjusted to 10:1, thereby preparing the platinum-carbon catalyst. The RDE test results of this catalyst are listed in Table 1. In this platinum-carbon catalyst, the proportion of metallic platinum particles with a particle size in the range of 3 - 5 nm is 83%. The onset potential of CO electrooxidation for this platinum-carbon catalyst is 0.78 V.

[0128] Example 4

[0129] The platinum-carbon catalyst was prepared using the same method as in Example 1, except that in step (7), while keeping the molar ratio of formic acid to ascorbic acid unchanged, the molar ratio of the reducing agent to chloroplatinic acid was adjusted to 5:1, thereby preparing the platinum-carbon catalyst. The RDE test results of this catalyst are listed in Table 1. In this platinum-carbon catalyst, the proportion of metallic platinum particles with a particle size in the range of 3 - 5 nm is 80%. The onset potential of CO electrooxidation for this platinum-carbon catalyst is 0.79 V.

[0130] Comparative Example 5

[0131] The platinum-carbon catalyst was prepared using the same method as in Example 1, except that in step (7), while keeping the molar ratio of formic acid to ascorbic acid unchanged, the molar ratio of the reducing agent to chloroplatinic acid was adjusted to 1.5:1, thereby preparing the platinum-carbon catalyst. The RDE test results of this catalyst are listed in Table 1. In this platinum-carbon catalyst, the proportion of metallic platinum particles with a particle size in the range of 3 - 5 nm is 60%. The onset potential of CO electrooxidation for this platinum-carbon catalyst is 0.80 V.

[0132] Example 5

[0133] The platinum-carbon catalyst was prepared using the same method as in Example 1, except that in step (7), ascorbic acid was not used, and only formic acid was used as the reducing agent with a dosage of 0.72 mol, thereby preparing the platinum-carbon catalyst. The RDE test results of this catalyst are listed in Table 1. In this platinum-carbon catalyst, the proportion of metallic platinum particles with a particle size in the range of 3 - 5 nm is 80%. The onset potential of CO electrooxidation for this platinum-carbon catalyst is 0.79 V.

[0134] Comparative Example 6

[0135] The platinum-carbon catalyst was prepared by the same method as in Example 1, except that in step (7), formic acid was not used, and only ascorbic acid was used as the reducing agent, and the amount of ascorbic acid was 0.72 mol, thus obtaining the platinum-carbon catalyst. The RDE test results of this catalyst are listed in Table 1. In this platinum-carbon catalyst, the proportion of platinum metal particles with a particle size in the range of 3-5 nm is 65%. The onset potential of CO electro-oxidation of this platinum-carbon catalyst is 0.80 V.

[0136] Example 6

[0137] The platinum-carbon catalyst was prepared by the same method as in Example 1, except that in step (5), the mixed solution of deionized water and glycerol was replaced with an equal volume of the mixed solution of ethylene glycol and glycerol, where the volume ratio of ethylene glycol to glycerol is 1:1, thus obtaining the platinum-carbon catalyst (denoted as Pt / C-70%-2). Samples were taken from the first dispersion to analyze the content of platinum in the liquid phase of the first dispersion, and further calculate C1 / C0 to be 0.116. The RDE test results of this catalyst are listed in Table 1. In this platinum-carbon catalyst, the proportion of platinum metal particles with a particle size in the range of 3-5 nm is 83%. The onset potential of CO electro-oxidation of this platinum-carbon catalyst is 0.78 V.

[0138] Example 7

[0139] The platinum-carbon catalyst was prepared by the same method as in Example 1, except that in step (5), the mixed solution of deionized water and glycerol was replaced with an equal volume of the mixed solution of glycerol and 1,2-propanediol, where the volume ratio of glycerol to 1,2-propanediol is 1:1, thus obtaining the platinum-carbon catalyst (denoted as Pt / C-70%-3). Samples were taken from the first dispersion to analyze the content of platinum in the liquid phase of the first dispersion, and further calculate C1 / C0 to be 0.078. The RDE test results of this catalyst are listed in Table 1. In this platinum-carbon catalyst, the proportion of platinum metal particles with a particle size in the range of 3-5 nm is 82%. The onset potential of CO electro-oxidation of this platinum-carbon catalyst is 0.78 V.

[0140] Example 8

[0141] The platinum-carbon catalyst was prepared in the same manner as in Example 1, except that in step (5), the mixed solution of deionized water and glycerol was replaced with an equal volume of a mixed solution of glycerol and 1,3-propanediol, wherein the volume ratio of glycerol to 1,3-propanediol was 1:1, thereby obtaining a platinum-carbon catalyst (denoted as Pt / C-70%-4). A sample was taken from the first dispersion to analyze the platinum content in the liquid phase of the first dispersion, and further calculate that C1 / C0 was 0.07. The RDE test results of this catalyst are listed in Table 1. In this platinum-carbon catalyst, the proportion of metallic platinum particles with a particle size in the range of 3-5 nm was 85%. The onset potential of CO electro-oxidation for this platinum-carbon catalyst was 0.78 V.

[0142] Example 9

[0143] The platinum-carbon catalyst was prepared in the same manner as in Example 1, except that in step (5), the mixed solution of deionized water and glycerol was replaced with an equal volume of a mixed solution of glycerol and 1,2-pentanediol, wherein the volume ratio of glycerol to 1,2-pentanediol was 1:1, thereby obtaining a platinum-carbon catalyst (denoted as Pt / C-70%-5). A sample was taken from the first dispersion to analyze the platinum content in the liquid phase of the first dispersion, and further calculate that C1 / C0 was 0.095. The RDE test results of this catalyst are listed in Table 1. In this platinum-carbon catalyst, the proportion of metallic platinum particles with a particle size in the range of 3-5 nm was 83%. The onset potential of CO electro-oxidation for this platinum-carbon catalyst was 0.78 V.

[0144] Example 10

[0145] (1) Vulcan XC-72R conductive carbon black was soaked in acetone (analytical grade) at a temperature of 60 °C for 8 h, wherein the mass ratio of acetone to conductive carbon black was 3:1. After soaking, suction filtration was carried out to obtain a solid phase material, and the solid phase material was dried at 100 °C for 12 h to obtain acetone-soaked conductive carbon black.

[0146] (2) The acetone-soaked conductive carbon black was mixed with hydrogen peroxide with a mass concentration of 30% (the mass ratio of hydrogen peroxide to carbon black was 3:1), and reacted at 60 °C for 8 h. After the reaction was completed, the reaction mixture was subjected to suction filtration, and the obtained solid phase material was dried at 100 °C for 12 h to obtain the first-oxidized conductive carbon black.

[0147] (3) The first-oxidized conductive carbon black was mixed with a 45% aqueous nitric acid solution (the mass ratio of HNO3 to conductive carbon black was 3:1), and reacted at 60 °C for 8 h. After the reaction was completed, the reaction mixture was subjected to suction filtration, and the obtained solid phase material was dried at 100 °C for 12 h to obtain the second-oxidized conductive carbon black.

[0148] (4) The secondarily oxidized conductive carbon black is calcined in a nitrogen atmosphere at a temperature of 400 °C for 8 h to obtain the pretreated conductive carbon black.

[0149] (5) 0.4 g of the pretreated conductive carbon black is added to a mixed solution of 400 mL of deionized water and glycerol (the volume ratio of water to glycerol is 1:3). After mixing evenly, 1 g of citric acid as a complexing agent is added, and then an aqueous solution of chloroplatinic acid (chloroplatinic acid is 3.2 mmol) is added. The resulting mixture is ultrasonically dispersed to form a first dispersion. Among them, the power of the ultrasonic wave is 500 W, and the time of ultrasonic dispersion is 0.5 h. A sample is taken from the first dispersion to analyze the content of platinum in the liquid phase of the first dispersion, and further calculate that C1 / C0 is 0.056.

[0150] (6) An aqueous solution of sodium carbonate is added to the first dispersion obtained by ultrasonic treatment to adjust the pH value of the first dispersion to 13 to obtain a second dispersion.

[0151] (7) The second dispersion is heated to 80 °C with a heater, and a reducing agent is added for a reduction reaction with stirring. Among them, the molar ratio of the reducing agent to chloroplatinic acid is 200:1. The reducing agent is a mixture of formic acid and ascorbic acid, where the addition amount of formic acid is 0.44 mol and the addition amount of ascorbic acid is 0.28 mol. After the addition of the reducing agent is completed, the heating condition of the heater remains unchanged, and the reaction continues for 10 h.

[0152] After the reaction is completed, the reduction reaction mixture is filtered to collect the solid phase material, and the solid phase material is washed with deionized water until the pH value of the filtrate is neutral. The washed solid phase material is vacuum dried at 100 °C for 8 h. The dried solid phase material is ground to obtain 1 g of a platinum-carbon catalyst. It is measured that the mass content of platinum in this platinum-carbon catalyst is 60 wt%, and the RDE test results of this catalyst are listed in Table 1. In this platinum-carbon catalyst, the proportion of metal platinum particles with a particle size in the range of 3 - 5 nm is 85%. The starting potential of CO electrooxidation of this platinum-carbon catalyst is 0.77 V.

[0153] Table 1

[0154]

[0155]

[0156] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A method for preparing a platinum-carbon catalyst, the method comprising the following steps: Step S1: Soak a carbon-based raw material with an organic solvent to obtain a first carbon-based material, wherein the organic solvent is a ketone solvent; Step S2: Contact the first carbon-based material with an oxidant to obtain a second carbon-based material, wherein the oxidant is one or more selected from peroxides; Step S3: Contact the second carbon-based material with nitric acid to obtain a third carbon-based material; Step S4: Roast the third carbon-based material in an inert atmosphere to obtain a carbonaceous support, wherein the roasting temperature is 300 - 600 °C; Step S5: Ultrasonically disperse the carbonaceous support, a platinum precursor, and a complexing agent in a coupling solvent to obtain a first dispersion, wherein the coupling solvent is a first coupling solvent or a second coupling solvent, the first coupling solvent contains water and at least one C2 - C8 polyol, the second coupling solvent contains at least two C2 - C8 polyols, wherein the molar concentration of the platinum precursor is C0, and the molar concentration of platinum in the liquid phase of the first dispersion obtained in Step S5 is C1, and C1 / C0 < 0.2; Step S6: Add a pH regulator to the first dispersion to adjust the pH value of the first dispersion to be alkaline, obtaining a second dispersion; Step S7: In an inert atmosphere, contact the second dispersion with a reducing agent to reduce at least part of the platinum precursor to metallic platinum, and at least part of the reducing agent is formic acid.

2. The method according to claim 1, wherein, In Step S1, the organic solvent is acetone.

3. The method according to claim 1, wherein, In Step S1, the volume ratio of the organic solvent to the carbon-based raw material is 1 - 3:

1.

4. The method according to any one of claims 1 to 3, wherein In Step S1, the temperature of the organic solvent is 50 - 70 °C, and the duration of the soaking is 5 - 12 hours.

5. The method according to claim 1, wherein In Step S2, the oxidant is hydrogen peroxide.

6. The method according to claim 1, wherein In Step S2, the mass ratio of the oxidant to the first carbon-based material is 1 - 3:

1.

7. The method according to any one of claims 1, 5, and 6, wherein In Step S2, the temperature of the contact is 50 - 70 °C, and the duration of the contact is 5 - 12 hours.

8. The method according to claim 1, wherein, In Step S3, the mass ratio of nitric acid to the second carbon-based material is 1 - 3:1, and the nitric acid is calculated as HNO3.

9. The method according to claim 1 or 8, wherein In Step S3, the temperature of the contact is 50 - 70 °C, and the duration of the contact is 5 - 12 hours.

10. The method according to claim 1, wherein, In Step S4, the roasting is carried out at a temperature of 300 - 400 °C.

11. The method according to claim 1 or 10, wherein, In Step S4, the duration of the roasting is 5 - 12 hours.

12. The method according to claim 1, wherein, In Step S5, the polyol is one or more of ethylene glycol, 1,2 - propanediol, 1,3 - propanediol, glycerol, and 1,2 - pentanediol.

13. The method according to claim 1, wherein, In Step S5, the dosage of the platinum precursor relative to the coupling solvent is 1 - 20 g / L.

14. The method according to claim 1, wherein In Step S5, the dosage of the platinum precursor relative to the coupling solvent is 2 - 10 g / L.

15. The method according to claim 1, wherein, In Step S5, the dosage of the platinum precursor relative to the coupling solvent is 3 - 6 g / L.

16. The method according to claim 1, wherein, In Step S5, in the first coupling solvent, the volume ratio of water to the polyol is 1:1 - 5.

17. According to the method of claim 1 or 16, in Step S5, the first coupling solvent is water and at least one triol.

18. According to the method described in claim 1 or 16, in step S5, the first coupling solvent is water and glycerol.

19. The method according to claim 1, wherein, In step S5, the second coupling solvent contains at least one diol and at least one triol, and the volume ratio of the diol to the triol is 1:1 - 5.

20. The method according to claim 19, wherein, In step S5, the diol is one or more of ethylene glycol, 1,2 - propanediol, 1,3 - propanediol, and 1,2 - pentanediol, and the triol is glycerol.

21. The method according to claim 1, wherein, In step S5, the complexing agent is one or more of citric acid, sodium citrate, sodium oxalate, sodium ethylenediaminetetraacetate, and sodium tartrate.

22. The method according to claim 1 or 21, wherein In step S5, the mass ratio of the platinum precursor to the complexing agent is 1:0.1 - 7.

23. The method according to claim 1 or 21, wherein In step S5, the mass ratio of the platinum precursor to the complexing agent is 1:0.2 - 3.

24. The method according to claim 1 or 21, wherein, In step S5, the mass ratio of the platinum precursor to the complexing agent is 1:0.4 - 1.

25. The method according to any one of claims 1, 12 - 16, 19, and 21, wherein, In step S5, the mass ratio of the platinum precursor to the carbonaceous support is 1.5 - 10:

1.

26. The method according to any one of claims 1, 12 - 16, 19, and 21, wherein In step S5, the mass ratio of the platinum precursor to the carbonaceous support is 3 - 8:

1.

27. The method according to any one of claims 1, 12 - 16, 19, and 21, wherein, In step S5, the mass ratio of the platinum precursor to the carbonaceous support is 4 - 6:

1.

28. The method according to any one of claims 1-3, 5, 6, 8, 10, 12-16, 19 and 21, wherein, The carbon - based raw material is conductive carbon black.

29. The method according to claim 1, wherein In step S6, the pH value of the first dispersion is adjusted to 8 - 14.

30. The method according to claim 1, wherein, In step S6, the pH value of the first dispersion is adjusted to 10 - 13.

31. The method according to claim 1, wherein In step S7, the reducing agent is ascorbic acid and formic acid.

32. The method according to claim 1 or 31, wherein, The reducing agent is ascorbic acid and formic acid.

33. The method according to claim 32, wherein, The molar ratio of ascorbic acid to formic acid is 1:0.5 - 10.

34. The method according to claim 32, wherein, The molar ratio of ascorbic acid to formic acid is 1:0.8 - 8.

35. The method according to claim 32, wherein, The molar ratio of ascorbic acid to formic acid is 1:1.2 - 5.

36. The method according to claim 1 or 31, wherein In step S7, the molar ratio of the reducing agent to the platinum precursor is 5 - 1000:1, with the platinum precursor calculated as platinum element.

37. The method according to claim 1 or 31, wherein, In step S7, the molar ratio of the reducing agent to the platinum precursor is 10 - 500:1, with the platinum precursor calculated as platinum element.

38. The method according to claim 1 or 31, wherein In step S7, the molar ratio of the reducing agent to the platinum precursor is 100 - 400:1, with the platinum precursor calculated as platinum element.

39. The method according to claim 1 or 31, wherein, In step S7, the molar ratio of the reducing agent to the platinum precursor is 150 - 300:1, with the platinum precursor calculated as platinum element.

40. The method according to claim 1 or 31, wherein, In step S7, the temperature of the contact is 50 - 140 °C.

41. The method according to claim 1 or 31, wherein, In step S7, the temperature of the contact is 70 - 100 °C.

42. The method according to claim 1 or 31, wherein, In step S7, the temperature of the contact is 75 - 85 °C.

43. The method according to claim 1 or 31, wherein, In step S7, the contact time is 4 - 12 hours.

44. The method according to claim 1 or 31, wherein, In step S7, the inert atmosphere is an atmosphere formed by nitrogen and / or noble gases.

45. The method according to any one of claims 1-3, 5, 6, 8, 10, 12-16, 19, 21, 29-31, wherein, In step S5, C1 / C0 is 0.05 - 0.

15.

46. A platinum - carbon catalyst prepared by the method according to any one of claims 1 - 45.

47. The platinum-carbon catalyst according to claim 46, wherein, The platinum - carbon catalyst contains a carbonaceous support and metal platinum particles supported on the carbonaceous support. In the platinum - carbon catalyst, at least 80% of the metal platinum particles have a particle size in the range of 3 - 5 nm, and the onset voltage of the platinum - carbon catalyst for CO electro - oxidation is lower than 0.8 V.

48. The platinum-carbon catalyst according to claim 46, wherein, In the platinum-carbon catalyst, 80-85% of the metal platinum particles have a particle size in the range of 3-5 nm, and the onset voltage of the platinum-carbon catalyst for catalytic CO electro-oxidation is 0.75-0.79 V.

49. The platinum-carbon catalyst according to any one of claims 46-48, wherein, Based on the total amount of the platinum-carbon catalyst, by element, in the platinum-carbon catalyst, the content of platinum is 40-80% by weight, and the content of the carbonaceous carrier is 20-60% by weight, and the carbonaceous carrier is calculated based on carbon element.

50. The platinum-carbon catalyst according to any one of claims 46-48, wherein, Based on the total amount of the platinum-carbon catalyst, the content of the platinum element is 60-70% by weight, and the content of the carbonaceous carrier is 30-40% by weight, and the carbonaceous carrier is calculated based on carbon element.

51. The platinum-carbon catalyst according to any one of claims 46-48, wherein The carbonaceous carrier is conductive carbon black.

52. Application of the platinum-carbon catalyst according to any one of claims 46-51 in a fuel cell.

53. A hydrogen fuel cell, wherein the anode and / or cathode of the hydrogen fuel cell contains the platinum-carbon catalyst according to any one of claims 46-51.

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