Platinum-carbon catalysts, their preparation methods and applications, and hydrogen fuel cells

Abstract

This invention discloses a platinum-carbon catalyst, its preparation method, its application, and a hydrogen fuel cell using the platinum-carbon catalyst. The platinum-carbon catalyst comprises a carbonaceous support and platinum particles supported on the carbonaceous support, at least some of which contain lattice dislocations. The platinum-carbon catalyst according to this invention exhibits high electrochemical stability and maintains high catalytic activity even during long-term continuous operation. The preparation method of the platinum-carbon catalyst according to this invention involves mixing carbonaceous materials, a platinum precursor, a complexing agent, and a dispersant, followed by the addition of a reducing agent. Through a one-step liquid-phase reduction-loading coupling process, the reduction and loading of the platinum precursor are directly achieved. This process is simple, easy to operate, and suitable for large-scale, mass production of platinum-carbon catalysts.

Description

Technical Field

[0001] This invention relates to a platinum-carbon catalyst, its preparation method and application, and also to a hydrogen fuel cell using the platinum-carbon catalyst. Background Technology

[0002] With continuous social development and progress, the consumption of traditional fossil fuels is constantly increasing, and fossil fuel resources are becoming increasingly depleted. At the same time, the use of fossil fuels generates large amounts of waste gas and solid dust pollutants, causing many irreversible damages to the environment. To address the energy and environmental problems caused by fossil fuel use, researchers have developed and explored many efficient and clean new energy sources, among which hydrogen energy has advantages such as high calorific value, cleanliness, and renewability. Based on current technological levels, the most effective form of hydrogen energy utilization is in hydrogen fuel cells. If hydrogen can be used as fuel for automobiles, then there will be no more CO2 production and emissions in the exhaust, which can significantly improve environmental pollution problems.

[0003] Hydrogen energy has a wide range of sources; refinery byproducts, water electrolysis, and photocatalytic water splitting can all be used to produce hydrogen. However, the primary use of hydrogen energy is through fuel cells (PEMFCs). The electrolyte in a PEMFC is a fully solid-state polymer, and the widely used one is the perfluorosulfonic acid Nafion membrane, also known as a proton exchange membrane, produced by DuPont. The working principle of a PEMFC is as follows: The fuel gas is humidified through auxiliary equipment, allowing H2 to pass through gas channels on the bipolar plates, through the diffusion layer, and to the anode catalyst layer. There, under the action of a Pt-based catalyst, a hydrogen oxidation reaction occurs, producing hydrogen ions. Subsequently, the hydrogen ions are transferred to the cathode through the sulfonic acid groups on the proton exchange membrane. Simultaneously, the oxygen humidified at the cathode undergoes an oxygen reduction reaction, and electrons flow through the external circuit through the load to the cathode. The overall reaction is the formation of water from H2 and O2.

[0004] Currently, the main catalysts for PEMFCs are platinum-carbon catalysts (Pt / C catalysts). The working mechanism of Pt / C catalysts on proton exchange membranes is relatively complex. They are active components of the hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR). Among them, the cathode reaction (ORR) is the rate-determining reaction of the kinetics. Therefore, developing efficient and stable ORR electrocatalysts is crucial for improving the reaction rate of fuel cells.

[0005] Based on the actual operating conditions of current passenger vehicles, the Pt / C catalysts used in fuel cells have a high Pt loading. For the cathode, the Pt loading in the Pt / C catalyst is typically 40% to 70% by weight. The carbon used as the support usually needs to be conductive carbon black with a large specific surface area. Due to the large Pt loading, in addition to optimizing the support, the loading process also greatly affects the dispersion of Pt on the support, thus affecting the Pt dispersion degree, i.e., the Pt utilization rate. Simultaneously, the reaction surface of a proton exchange membrane fuel cell is a strongly acidic environment. Under electrocatalytic reaction, not only carbon corrosion but also electrochemical and chemical corrosion of Pt occur in the Pt / C catalyst, resulting in dissolution and re-precipitation processes. This leads to the coalescence and agglomeration of Pt particles. In this process, small Pt particles become smaller and large particles become larger, ultimately resulting in a two-stage dispersion process that severely affects the stability of the Pt / C catalyst.

[0006] According to existing literature, Pt particles with a diameter of 3-5 nm exhibit the highest ORR (Oriented Reactivity Ratio), indicating the highest Pt utilization. However, due to the very high Pt / C loading, current preparation methods struggle to produce Pt catalysts with uniform particle size. Under actual operating conditions, the Pt particle size gradually increases and reconfigures, leading to non-uniformity in Pt particle size. This phenomenon is even more pronounced in single-cell tests.

[0007] Therefore, there is an urgent need in this field for platinum-carbon catalysts with high long-term operational stability and their preparation methods. Summary of the Invention

[0008] The purpose of this invention is to provide a platinum-carbon catalyst and its preparation method, which exhibits high long-term operational stability.

[0009] According to a first aspect of the present invention, a platinum-carbon catalyst is provided, the platinum-carbon catalyst comprising a carbonaceous support and platinum particles supported on the carbonaceous support, wherein at least a portion of the platinum particles contain lattice dislocations.

[0010] According to a second aspect of the present invention, a method for preparing a platinum-carbon catalyst is provided, the method comprising the following steps:

[0011] S1. A dispersion is provided, comprising a carbonaceous material, a platinum precursor, a complexing agent, a first dispersion medium, and a second dispersion medium, wherein the first dispersion medium is an alcohol with a boiling point of 80°C or higher at 1 standard atmosphere, the second dispersion medium is water, and the complexing agent is a water-soluble salt of a monocarboxylic acid, wherein the molar concentration of the platinum precursor is C0, the molar concentration of platinum in the liquid phase of the dispersion is C1, and C1 / C0 < 0.5;

[0012] S2. Under reduction reaction conditions sufficient to reduce the platinum precursor in the dispersion to metallic platinum, the dispersion is contacted with a reducing agent to obtain a reduction reaction mixture, wherein the reducing agent contains vitamin C;

[0013] S3. The reduction reaction mixture is subjected to solid-liquid separation to obtain a solid phase. The solid phase is washed and dried to obtain the platinum-carbon catalyst.

[0014] According to a 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.

[0015] According to a fourth aspect of the invention, the invention provides the application of the platinum-carbon catalyst described in the first or third aspect of the invention in a fuel cell.

[0016] According to a fifth aspect of the present invention, a hydrogen fuel cell is provided, wherein the anode and / or cathode of the hydrogen fuel cell contain the platinum-carbon catalyst described in the first or third aspect of the present invention.

[0017] The platinum-carbon catalyst according to the present invention has high stability. The ORR polarization curve and cyclic voltammetry curve after 5000 continuous cycles of catalyst operation show that the half-wave potential decrease is minimal and the decrease in electrochemical active area is within 3%. The long-term test results of membrane electrode show that after 40 hours of operation, the output voltage retention rate of the platinum-carbon catalyst according to the present invention is above 95%, and the peak output power density remains basically unchanged before and after decay.

[0018] According to the preparation method of the platinum-carbon catalyst of the present invention, carbonaceous materials, platinum precursor, complexing agent and dispersant are mixed and then a reducing agent is added. The reduction and loading of platinum precursor are directly realized through a one-step liquid-phase reduction-loading coupling process. The process is simple, easy to operate and suitable for large-scale batch production of platinum-carbon catalyst. Attached Figure Description

[0019] Figure 1 Transmission electron microscopy (TEM) image of the platinum-carbon catalyst prepared in Example 1;

[0020] Figure 2 A photograph of a region from a single perspective and the particle size statistics of the platinum-carbon catalyst prepared in Example 1, obtained from transmission electron microscopy analysis.

[0021] Figure 3 This is a comparison of the polarization curves of the platinum-carbon catalyst prepared in Example 1 before and after 5000 cycles.

[0022] Figure 4 This is a comparison of the electrochemical active area of ​​the platinum-carbon catalyst prepared in Example 1 before and after 5000 cycles.

[0023] Figure 5 ORR polarization curves of a commercial platinum-carbon catalyst (JM HiSPEC 13100-70wt.%Pt / C) before and after 5000 cycles;

[0024] Figure 6 ORR polarization curves of the platinum-carbon catalyst prepared for Comparative Example 1 before and after 5000 cycles;

[0025] Figure 7 The results show the long-term stability test results of membrane electrodes prepared using the platinum-carbon catalyst prepared in Example 1 and the commercial platinum-carbon catalyst (JM HiSPEC13100-70wt.%Pt / C).

[0026] Figure 8-1 Here is a high-resolution aberration electron microscope image of the platinum-carbon catalyst prepared in Example 1;

[0027] Figure 8-2 High-resolution aberration electron microscope image of the platinum-carbon catalyst prepared for Comparative Example 1;

[0028] Figure 8-3 High-resolution aberration-corrected electron microscope image of a commercial platinum-carbon catalyst;

[0029] Figure 9 and Figure 10 High-resolution aberration electron micrograph of the platinum-carbon catalyst prepared in Example 1, showing lattice dislocations. Detailed Implementation

[0030] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0031] According to a first aspect of the present invention, a platinum-carbon catalyst is provided, the platinum-carbon catalyst comprising a carbonaceous support and platinum metal particles supported on the carbonaceous support.

[0032] In the platinum-carbon catalyst according to the present invention, at least a portion of the platinum particles contain lattice dislocations. In the platinum-carbon catalyst according to the present invention, the content of platinum particles containing lattice dislocations is 50% or more.

[0033] In this invention, the term "lattice dislocation" refers to a lattice defect on a single nanoparticle caused by the local irregular arrangement of atoms. In this invention, spherical aberration electron microscopy can be used to observe the boundary between the slipped and unslipped portions, thereby confirming the presence of lattice dislocations in the nanoparticle. In this invention, the content of platinum particles containing lattice dislocations is defined as the proportion of randomly selected 400 platinum particles tested out of all the tested platinum particles.

[0034] According to the platinum-carbon catalyst of the present invention, at least a portion of the surface of the platinum particles forms amorphous carbon after electron beam irradiation. The formation of amorphous carbon on the surface of the platinum particles after electron beam irradiation indicates that the surface of the platinum particles has a coating layer. The accelerating voltage of the electron beam is 200 kV. The coating layer is derived from the complexing agent and / or reducing agent used in the preparation of the platinum-carbon catalyst. The coating layer can enhance the interaction between the platinum particles and the carbonaceous support, and also form a protective layer on the surface of the platinum particles. The specific types of the complexing agent and the reducing agent will be described in detail below, and will not be described in detail here.

[0035] According to the platinum-carbon catalyst of the present invention, the average particle size of the platinum metal particles is 3-6 nm.

[0036] In this invention, the average particle size of the platinum particles was determined by transmission electron microscopy.

[0037] According to the platinum-carbon catalyst of the present invention, the platinum content, based on the total amount of the platinum-carbon catalyst, can be 10-70% by weight, preferably 30-70% by weight, more preferably 40-70% by weight, and the carbon support content can be 30-90% by weight, preferably 30-70% by weight, more preferably 30-60% by weight, wherein the carbon support is calculated as carbon. In a particularly preferred embodiment, based on the total amount of the platinum-carbon catalyst, the platinum content is 50-70% by weight, and the carbon support content is 30-50% by weight, wherein the carbon support is calculated as carbon.

[0038] In this invention, the content of metallic platinum in the platinum-carbon catalyst is determined by inductively coupled plasma spectroscopy (ICP).

[0039] According to the platinum-carbon catalyst of the present invention, the carbonaceous support is conductive carbon black. Preferred examples of the conductive carbon black may include, but are not limited to, one or more of Vulcan XC72, Ketjen EC300J, Ketjen EC600J, Blackpearls 2000, and Blackpearls 3000. The specific surface area of ​​the conductive carbon black is preferably 200-2000 m². 2 / g, more preferably 250-1500m 2 / g. In this invention, the specific surface area is determined using the BET method.

[0040] The platinum-carbon catalyst according to the present invention exhibits good stability. The electrochemical active area of ​​the platinum-carbon catalyst according to the present invention after 5000 cycles is ECSA. 5000 The initial electrochemical active area of ​​this platinum-carbon catalyst is ECSA. 初始 ECSA 5000 ECSA 初始 It is above 0.9, generally 0.92-0.99, preferably 0.95-0.99, and even more preferably 0.97-0.99.

[0041] According to a second aspect of the present invention, a method for preparing a platinum-carbon catalyst is provided, the method comprising the following steps:

[0042] S1. A dispersion is provided, the dispersion comprising a carbonaceous material, a platinum precursor, a complexing agent, a first dispersion medium, and a second dispersion medium;

[0043] S2. Under reduction reaction conditions sufficient to reduce the platinum precursor in the dispersion to metallic platinum, the dispersion is contacted with a reducing agent to obtain a reduction reaction mixture, wherein the reducing agent is an acidic reducing agent.

[0044] S3. The reduction reaction mixture is subjected to solid-liquid separation to obtain a solid phase. The solid phase is washed and dried to obtain the platinum-carbon catalyst.

[0045] In step S1, the first dispersion medium is an alcohol with a boiling point of 80°C or higher at 1 standard atmosphere, preferably an alcohol with a boiling point of 90°C or higher at 1 standard atmosphere, more preferably an alcohol with a boiling point of 120°C or higher at 1 standard atmosphere, and even more preferably an alcohol with a boiling point of 150°C or higher at 1 standard atmosphere. The alcohol can be a monohydric alcohol, a dihydric alcohol, or a polyhydric alcohol. A polyhydric alcohol refers to an alcohol whose molecular structure contains three or more hydroxyl groups. The alcohol is preferably an aliphatic alcohol, including straight-chain alcohols and alicyclic alcohols. Generally, the alcohol is a liquid at room temperature (15-40°C). According to the method of the present invention, preferred examples of the first dispersion medium in step S1 include, but are not limited to, one or more of ethylene glycol, n-propanol, isopropanol, 1,2-propanediol, 1,3-propanediol, glycerol, n-butanol, and pentanediol. Preferably, the first dispersion medium is a dihydric alcohol and / or a polyhydric alcohol. The second dispersion medium is water. According to the method of the present invention, in a preferred embodiment, the first dispersion medium is one or more of ethylene glycol, 1,2-propanediol, 1,3-propanediol, glycerol, n-butanol, and pentanediol, and the second dispersion medium is water. In this preferred embodiment, the first dispersion medium is more preferably ethylene glycol. In step S1, the volume ratio of the second dispersion medium to the first dispersion medium is preferably 1:1-5, more preferably 1:1-3.

[0046] In step S1, the amounts of the first and second dispersion media can be selected based on the amounts of the platinum precursor and the carbonaceous support. Preferably, in step S1, the concentration of the platinum precursor relative to the total amount of the first and second dispersion media is 1-30 g / L. More preferably, in step S1, the concentration of the platinum precursor relative to the total amount of the first and second dispersion media is 3-20 g / L. Even more preferably, in step S1, the concentration of the platinum precursor relative to the total amount of the first and second dispersion media is 6-15 g / L.

[0047] In step S1, the complexing agent is one or more water-soluble salts of a monocarboxylic acid, such as an alkali metal salt and / or an ammonium salt of a monocarboxylic acid. In this invention, the complexing agent can be one or more compounds represented by Formula I.

[0048] R-COOM (Formula I)

[0049] In Formula I, R can be hydrogen, a C1-C6 alkyl group, or a C1-C6 haloalkyl group, and M can be an alkali metal ion or an ammonium ion (-NH4). + ).

[0050] In this invention, the C1-C6 alkyl groups include straight-chain alkyl groups of C1-C6 and branched alkyl groups of C3-C6. Specific examples may include, but are not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, n-hexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2,3-dimethylbutyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl, or 2-ethylbutyl.

[0051] In this invention, the halogen atom in the haloalkyl group can be fluorine, chlorine or bromine, preferably chlorine.

[0052] Specific examples of the complexing agent may include, but are not limited to, one or more of sodium formate, sodium acetate, ammonium acetate, sodium propionate, ammonium propionate, sodium butyrate, sodium valerate, sodium hexanoate, sodium monochloroacetate, sodium dichloroacetate, and sodium trichloroacetate.

[0053] Preferably, the complexing agent is one or more of sodium formate, sodium acetate, sodium monochloroacetate, sodium dichloroacetate, and sodium trichloroacetate. More preferably, the complexing agent is sodium formate and / or sodium acetate.

[0054] In step S1, the mass ratio of the platinum precursor to the complexing agent is preferably 1:0.01-1, more preferably 1:0.05-0.5, and even more preferably 1:0.1-0.2.

[0055] In step S1, the carbonaceous support is conductive carbon black. Preferred examples of the conductive carbon black may include, but are not limited to, one or more of Vulcan XC72, Ketjen EC300J, Ketjen EC600J, Blackpearls 2000, and Blackpearls 3000. In step S1, the specific surface area of ​​the carbonaceous material may be 200-2000 m². 2 / g, preferably 250-1500m 2 / g.

[0056] In step S1, the platinum precursor can be a platinum compound that can be reduced to metallic platinum by a reducing agent under reducing reaction conditions. According to the method of the present invention, the platinum precursor can be one or more of the following: platinum acetylacetonate, sodium chloroplatinate, ammonium hexachloroplatinate, potassium hexachloroplatinate, sodium hexachloroplatinate, platinum tetrachloride, platinum tetraamminenitrate, platinum nitrate, chloroplatinic acid, potassium chloroplatinate, and sodium chloroplatinate. Preferably, the platinum precursor is chloroplatinic acid.

[0057] According to the method of the present invention, in step S1, the method of providing the dispersion may include:

[0058] S1-1. Carbonaceous material, platinum precursor, first dispersion medium and second dispersion medium are dispersed by ultrasound to form a suspension.

[0059] S1-2. Add the complexing agent to the suspension and disperse it using ultrasound to obtain the dispersion.

[0060] In steps S1-1 and S1-2, the power of the ultrasonic wave is preferably 50W to 3kW, more preferably 1000W to 2000W. The duration of ultrasonic dispersion can be selected according to the power and frequency of the ultrasonic wave. Preferably, the dispersion time using ultrasonic waves is 15 minutes to 2 hours. Preferably, the dispersion time using ultrasonic waves is 30 minutes to 1 hour. This invention does not particularly limit the device used for ultrasonic dispersion; any common device capable of ultrasonic dispersion can be used.

[0061] According to the method of the present invention, in the dispersion provided in step S1, the molar concentration of the platinum precursor is C0, where C0 = m Pt / V 分散介质 , where m Pt V is the amount of substance of the platinum precursor, expressed in moles. 分散介质 The molar concentration of platinum in the liquid phase of the dispersion provided in step S1 is C1, where C1 / C0 < 0.5. Preferably, C1 / C0 < 0.3. More preferably, C1 / C0 is 0.2-0.3.

[0062] In this invention, the molar concentration C1 of platinum in the liquid phase of the dispersion is determined by inductively coupled plasma atomic emission spectrometry (ICP). The specific test method is as follows: (1) Determine the mass and volume of the dispersion; (2) Take a certain volume of dispersion liquid from the dispersion, the volume of which is V1; (3) Filter this volume V1 of dispersion liquid through a mobile phase filter (the pore size of the filter membrane is 0.22 μm), wash the solid phase with deionized water, collect the filtered liquid phase and the washing liquid to obtain the liquid phase, the total volume of the liquid phase is V2, and then take a sample from the liquid phase to determine the molar concentration of platinum in the liquid phase by ICP, which is counted as C2; then the molar concentration of platinum in the dispersion C1=C2×V2 / V1.

[0063] According to the method of the present invention, in step S2, before contacting the dispersion with the reducing agent, the pH value of the dispersion obtained in step S1 is adjusted to 8-14, preferably 8-12, and more preferably 9-11. A pH adjuster can be added to the dispersion to adjust the pH value to 8-14, preferably 8-12, and more preferably 9-11. The pH adjuster is preferably one or more of sodium carbonate, potassium carbonate, ammonia, potassium hydroxide, and sodium hydroxide. The pH adjuster is preferably provided in the form of an aqueous solution, and the concentration of the aqueous solution can be conventionally selected and is not particularly limited.

[0064] According to the method of the present invention, in step S2, the reducing agent contains vitamin C. In a preferred embodiment, the reducing agent is vitamin C and a second reducing agent, wherein the second reducing agent is one or more of citric acid and tartaric acid, and the molar ratio of vitamin C to the second reducing agent can be 0.1-10:1, preferably 1-5:1. In a particularly preferred embodiment, the reducing agent is vitamin C.

[0065] According to the method of the present invention, the amount of reducing agent can be selected according to the amount of platinum precursor. According to the method of the present invention, in step S2, the amount of reducing agent is preferably added in excess of the stoichiometric ratio. Preferably, in step S2, the molar ratio of the reducing agent to the platinum precursor is 5-200:1. From the perspective of further improving the electrochemical catalytic activity of the finally prepared platinum-carbon catalyst, in step S2, the molar ratio of the reducing agent to the platinum precursor is preferably 8-100:1. More preferably, in step S3, the molar ratio of the reducing agent to the platinum precursor is 10-50:1, for example, it can be 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 21:1, 22:1, 23:1, 24:1, 25:1, 26:1, 27:1, 28:1, 29:1, 30:1, 31:1, 32:1, 33:1, 34:1, 35:1, 36:1, 37:1, 38:1, 39:1, 40:1, 41:1, 42:1, 43:1, 44:1, 45:1, 46:1, 47:1, 48:1, 49:1, or 50:1. More preferably, in step S2, the molar ratio of the reducing agent to the platinum precursor is 10-30:1.

[0066] According to the method of the present invention, in step S2, the contact can be carried out at a temperature of 50-100°C, preferably at a temperature of 55-90°C. In a more preferred embodiment, in step S2, the contact is carried out at a temperature of 50-80°C. According to the method of the present invention, in step S2, the reducing agent can be added after the temperature of the dispersion is raised to the reduction reaction temperature, or the reducing agent can be added to the dispersion first, and then the temperature is raised to the reduction reaction temperature. In step S2, the duration of the reduction reaction can be selected according to the temperature of the reduction reaction. Generally, in step S2, the duration of the reduction reaction can be 2-12 hours, preferably 3-8 hours, more preferably 4-6 hours. In step S2, the reduction reaction is carried out in an inert atmosphere, for example, in an atmosphere of nitrogen and / or group zero gases (such as argon and / or helium).

[0067] According to the method of the present invention, in step S3, a solid phase substance can be separated from the reduction reaction mixture obtained in step S2 using conventional separation methods. The separated solid phase substance is then washed with water and dried sequentially to obtain a platinum-carbon catalyst. Generally, the reduction mixture obtained in step S2 can be subjected to solid-liquid separation by one or more of the following methods: filtration, centrifugation, and sedimentation, to obtain the solid phase substance. The drying can be heat drying or freeze drying. The heat drying can be carried out at a temperature of 55-85°C, preferably 60-70°C; the freeze drying can be carried out at a temperature of -30°C to 5°C. The duration of the drying can be selected according to the drying method and the drying temperature, and is generally 4-24 hours.

[0068] The platinum-carbon catalyst prepared by the method of the present invention has high electrochemical stability.

[0069] According to a 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.

[0070] The platinum-carbon catalyst prepared by the method described in the second aspect of this invention contains at least a portion of the platinum particles with lattice dislocations. According to the platinum-carbon catalyst of this invention, the content of platinum particles containing lattice dislocations is 50% or more.

[0071] The platinum-carbon catalyst prepared by the method described in the second aspect of this invention has at least a portion of its surface covered by an electron beam irradiation to form amorphous carbon. The formation of amorphous carbon on the surface of the platinum particles after electron beam irradiation indicates that the platinum particles have a coating layer. This coating layer originates from the complexing agent and / or reducing agent used in the preparation of the platinum-carbon catalyst. This coating layer enhances the interaction between the platinum particles and the carbonaceous support, and also forms a protective layer on the surface of the platinum particles.

[0072] The platinum-carbon catalyst prepared by the method described in the second aspect of the present invention has an average particle size of 3-6 nm for the metallic platinum particles.

[0073] The platinum-carbon catalyst prepared by the method described in the second aspect of the present invention, based on the total amount of the platinum-carbon catalyst, has a platinum content of 10-70% by weight, preferably 30-70% by weight, more preferably 40-70% by weight, and a carbon support content of 30-90% by weight, preferably 30-70% by weight, more preferably 30-60% by weight, wherein the carbon support is calculated as carbon. In a particularly preferred embodiment, based on the total amount of the platinum-carbon catalyst, the platinum content is 50-70% by weight, and the carbon support content is 30-50% by weight, wherein the carbon support is calculated as carbon.

[0074] The platinum-carbon catalyst prepared by the method described in the second aspect of this invention exhibits good stability, and the electrochemical active area of ​​the platinum-carbon catalyst after 5000 cycles is ECSA. 5000 The initial electrochemical active area of ​​this platinum-carbon catalyst is ECSA. 初始 ECSA 5000 ECSA 初始 It is above 0.9, generally 0.92-0.99, preferably 0.95-0.99, and even more preferably 0.97-0.99.

[0075] The platinum-carbon catalyst according to the present invention is particularly suitable for fuel cells. According to a fourth aspect of the present invention, the present invention provides the application of the platinum-carbon catalyst described in the first or third aspect of the present invention in fuel cells.

[0076] According to a fifth aspect of the present invention, a hydrogen fuel cell is provided, wherein the anode and / or cathode of the hydrogen fuel cell contain the platinum-carbon catalyst described in the first or third aspect of the present invention.

[0077] In the following examples and comparative examples, the composition of the platinum-carbon catalyst was determined by inductively coupled plasma atomic emission spectrometry (ICP).

[0078] In the following examples and comparative examples, transmission electron microscopy analysis was performed on a HITACHI transmission electron microscope purchased from Hitachi, Japan. The sample preparation method was as follows: a small amount of catalyst (usually about 1 mg) was weighed into 5 mL of 50% ethanol aqueous solution, ultrasonically dispersed for 5 min and mixed evenly to prepare a catalyst slurry. Then, a small amount of catalyst slurry was added dropwise (usually 1-2 drops) onto a copper grid using a dropper and dried under an infrared lamp for later use.

[0079] In the following examples and comparative examples, the test method for the average particle size of platinum particles in platinum-carbon catalysts is as follows: The sample is analyzed by transmission electron microscopy. Eight non-overlapping and widely dispersed viewing areas of the catalyst particles (magnification of 40,000-200,000 times) are randomly selected. Fifty platinum particles (400 in total) are randomly selected from each area. The particle size is counted, and the average particle size is taken as the average particle size of the platinum particles.

[0080] In the following examples and comparative examples, high-resolution spherical aberration electron microscopy was used to detect lattice defects and surface coatings of metallic platinum particles. The spherical aberration electron microscopy analysis was performed on a JEM-ARM300F spherical aberration-corrected scanning transmission electron microscope purchased from Nippon Electronics.

[0081] In the following examples and comparative examples, the molar concentration C1 of platinum in the liquid phase of the dispersion was determined by inductively coupled plasma atomic emission spectrometry (ICP). The specific test method was as follows: (1) the mass and volume of the dispersion were measured; (2) a certain volume of dispersion was quantitatively taken from the dispersion, the volume of which was V1; (3) this volume V1 of dispersion was filtered through a mobile phase filter (the pore size of the filter membrane was 0.22 μm), the solid phase was washed with deionized water, the filtered liquid phase and the washing liquid were collected to obtain the liquid phase, the total volume of which was V2. Then, a sample was taken from the liquid phase and the molar concentration of platinum in the liquid phase was determined by ICP, and it was recorded as C2. Then the molar concentration of platinum in the liquid phase of the dispersion was C1 = C2 × V2 / V1.

[0082] In the following examples and comparative examples, the electrochemical activity of the platinum-carbon catalyst was tested using the rotating disk method. The catalyst was prepared as a slurry and drop-coated onto a glassy carbon electrode with a diameter of 5 mm, then dried before testing (ensuring that the Pt loading on the electrode was 18-22 μg / cm³). 2 Within the specified range; the test conditions for the catalyst polarization curve were: 0.1M HClO4 solution, oxygen saturation, voltage scan range of 0-1.0V vs RHE, scan rate of 10mV / s, and rotating disk electrode speed of 1600r / min; the test conditions for the electrochemical active area were: 0.1M HClO4 solution, nitrogen saturation, voltage scan range of 0-1.0V vs RHE, and scan rate of 50mV / s. The hydrogen desorption peak area on the curve was integrated.

[0083] The formula for calculating the electrochemical active surface area (ECSA) of the platinum-carbon catalyst is as follows:

[0084]

[0085] Among them, S H Peak area

[0086] V represents the scan rate, which is 0.05v / s.

[0087] M pt The mass of Pt added to the glassy carbon electrode;

[0088] The mass-specific activity (A / mg) of platinum-carbon catalysts Pt The formula for calculating ) is:

[0089]

[0090] Among them, i k This is the dynamic current, measured in mA / cm². 2 Its calculation is based on the KL equation, which has the following form:

[0091]

[0092] i L The limiting diffusion current is directly read from the ORR curve.

[0093] m Pt The amount of Pt loaded on the glassy carbon electrode, in mg. Pt / cm 2 ;

[0094] The area-specific activity (mA / cm²) of platinum-carbon catalysts 2 The formula for calculating ) is:

[0095]

[0096] The following examples and comparative examples involve the following conductive carbon blacks:

[0097] (1) Conductive carbon black of brand name Ketjen EC 300J, purchased from Lion Corporation of Japan, with particle diameter ranging from 50 nm to 100 nm and specific surface area of ​​1400 m². 2 / g;

[0098] (2) Conductive carbon black of brand name Ketjen EC600J, purchased from Lion Corporation of Japan, with particle diameter in the range of 50-100 nm and specific surface area of ​​1500 m². 2 / g;

[0099] The specific surface area of ​​the conductive carbon black was measured using a JW-BK200 specific surface area meter purchased from Beijing Jingwei Gaobo.

[0100] Examples 1-5 are used to illustrate the present invention.

[0101] Example 1

[0102] (1) Preparation of dispersion

[0103] At room temperature (25°C, the same below), 0.03 g of Ketjen EC 600J conductive carbon black (hereinafter, "conductive carbon black" is sometimes simply referred to as "carbon black") and 0.2 g of chloroplatinic acid hexahydrate were added to 15 mL of a mixed solvent consisting of water and ethylene glycol (where the volume ratio of water to ethylene glycol was 1:1), and the mixture was ultrasonically dispersed for 20 minutes to form a suspension. Then, 30 mg of sodium acetate was added to the suspension, and the mixture was ultrasonically dispersed for 30 minutes to obtain a dispersion. The ultrasonic power was 1000 W. Samples were taken from the dispersion, and the molar concentration of platinum in the liquid phase of the dispersion was analyzed as C1, and the molar concentration of the platinum precursor relative to the dispersion medium was C0 (determined by the feed ratio, the same below), with C1 / C0 = 0.26.

[0104] (2) Reduction reaction

[0105] The dispersion obtained in step (1) was heated to 60°C, and a 1 mol / L sodium carbonate solution was added to adjust the pH to 9. Then, 1 g of vitamin C was added, and the reaction was carried out at 60°C for 4 hours. After cooling to room temperature, the reaction mixture was filtered, and the solid was collected. The solid was washed with deionized water until neutral, and then dried at 65°C for 12 hours to obtain the platinum-carbon catalyst according to the present invention. The platinum content in the platinum-carbon catalyst was determined to be 70% by weight. The electrochemical performance data of the platinum-carbon catalyst are listed in Table 1.

[0106] Comparative Example 1

[0107] The platinum-carbon catalyst was prepared using the same method as in Example 1, except that sodium acetate was not used in step (1). The prepared platinum-carbon catalyst contained 70% by weight of metallic platinum. The electrochemical performance data of this platinum-carbon catalyst are listed in Table 1. Samples were taken from the dispersion, and the molar concentration of platinum in the liquid phase of the dispersion was analyzed as C1, and the molar concentration of the platinum precursor relative to the dispersion medium was C0, with C1 / C0 = 0.62.

[0108] Comparative Example 2

[0109] The platinum-carbon catalyst was prepared using the same method as in Example 1, except that ethylene glycol was not used in step (1); instead, an equal volume of ethanol was used. The prepared platinum-carbon catalyst contained 70% by weight of metallic platinum. The electrochemical performance data of this platinum-carbon catalyst are listed in Table 1. Samples were taken from the dispersion, and the molar concentration of platinum in the liquid phase of the dispersion was analyzed to be C1, and the molar concentration of the platinum precursor relative to the dispersion medium was C0, with C1 / C0 = 0.51.

[0110] Comparative Example 3

[0111] The platinum-carbon catalyst was prepared using the same method as in Example 1, except that sodium acetate was replaced with an equal mass of sodium chloride in step (1). The prepared platinum-carbon catalyst contained 70% by weight of metallic platinum. The electrochemical performance data of this platinum-carbon catalyst are listed in Table 1. Samples were taken from the dispersion, and the molar concentration of platinum in the liquid phase of the dispersion was analyzed to be C1, and the molar concentration of the platinum precursor relative to the dispersion medium was C0, with C1 / C0 = 0.53.

[0112] Comparative Example 4

[0113] The platinum-carbon catalyst was prepared using the same method as in Example 1, except that in step (2), vitamin C, which served as the reducing agent, was replaced by an equal mass of lactic acid. The prepared platinum-carbon catalyst contained 70% by weight of metallic platinum. The electrochemical performance data of this platinum-carbon catalyst are listed in Table 1.

[0114] Example 2

[0115] The platinum-carbon catalyst was prepared using the same method as in Example 1, except that in step (2), the amount of vitamin C was adjusted to 270 mg, and then hydrochloric acid was added dropwise to adjust the pH of the reaction system to the same level as in Example 1. The prepared platinum-carbon catalyst contained 70% by weight of metallic platinum. The electrochemical performance data of this platinum-carbon catalyst are listed in Table 1.

[0116] Example 3

[0117] The platinum-carbon catalyst was prepared using the same method as in Example 1, except that the reaction temperatures in step (2) were 50°C, 70°C, and 80°C, respectively. The prepared platinum-carbon catalyst contained 70% by weight of metallic platinum. The electrochemical performance data of the prepared platinum-carbon catalyst are listed in Table 1.

[0118] Example 4

[0119] The platinum-carbon catalyst was prepared using the same method as in Example 1, except that the amount of sodium acetate used in step (1) was 10 mg and 50 mg, respectively. The platinum content in the prepared platinum-carbon catalyst was determined to be 70% by weight. The electrochemical performance data of the prepared platinum-carbon catalyst are listed in Table 1. Samples were taken from the dispersion to analyze the molar concentration of platinum in the liquid phase of the dispersion. The molar concentration of platinum in the liquid phase of the dispersion was C1, and the molar concentration of the platinum precursor relative to the dispersion medium was C0. When the amount of sodium acetate was 10 mg, C1 / C0 = 0.31; when the amount of sodium acetate was 50 mg, the molar concentration of platinum in the liquid phase of the dispersion was C1 / C0 = 0.24.

[0120] Example 5

[0121] (1) Preparation of dispersion

[0122] At room temperature (25°C), 45 mg of Ketjen EC 300J conductive carbon black and 160 mg of chloroplatinic acid hexahydrate were added to 15 mL of a mixed solvent of water and ethylene glycol (volume ratio of water to ethylene glycol: 1:2), and dispersed by sonication for 35 minutes to form a suspension. Then, 20 mg of sodium formate was added to the suspension, and the suspension was sonicated for another 35 minutes to obtain a dispersion. The ultrasonic power was 2000 W. Samples were taken from the dispersion, and the molar concentration of platinum in the liquid phase of the dispersion was C1, and the molar concentration of the platinum precursor relative to the dispersion medium was C0, with C1 / C0 = 0.29.

[0123] (2) Reduction reaction

[0124] The dispersion obtained in step (1) was heated to 70°C, and 1 mol / L sodium carbonate was added to adjust the pH of the solution to 9. 1 g of vitamin C was added, and the reaction was carried out at 70°C for 4 hours. After cooling to room temperature, the reaction mixture was filtered, and the solid was collected. The solid was washed with deionized water until neutral, and then dried at 65°C for 24 hours to obtain the platinum-carbon catalyst according to the present invention. The platinum content in the platinum-carbon catalyst was determined to be 55% by weight. The electrochemical performance data of the platinum-carbon catalyst are listed in Table 1.

[0125] The experimental results of the examples and comparative examples are briefly described and analyzed below.

[0126] (1) Figure 1 Transmission electron microscopy (TEM) images of the platinum-carbon catalyst prepared in Example 1. From Figure 1 It can be seen that in the platinum-carbon catalyst prepared in Example 1, the particle size of the Pt particles, which are the active components, is very small; and the Pt particles are uniformly dispersed on the surface of the carbon material. Figure 2 The image shows a selected viewing angle and the particle size statistics for the transmission electron microscopy analysis of the platinum-carbon catalyst prepared in Example 1. Statistical analysis revealed that the average particle size of the Pt particles in the platinum-carbon catalyst prepared in Example 1 was 3 nm.

[0127] (2) Figure 3 and Figure 4 The ORR polarization curves and cyclic voltammetry curves of the platinum-carbon catalyst prepared in Example 1 before and after 5000 cycles are shown in Table 1. According to the experimental data, the platinum-carbon catalyst prepared in Example 1 is very stable. Before and after 5000 cycles, the decrease in half-wave potential is less than 3 mV, and the decrease in electrochemical active area is less than 3%.

[0128] Figure 5The ORR polarization curves of the commercial platinum-carbon catalyst (JM hispec 13100-70wt.%Pt / C, the same below) before and after 5000 cycles are shown. Combined with the experimental data in Table 1, it can be seen that the half-wave potential of the commercial platinum-carbon catalyst decreases by less than 3mV before and after 5000 cycles, but the decrease in its electrochemical active area exceeds 8%.

[0129] Figure 6 The ORR polarization curves of the platinum-carbon catalyst prepared in Comparative Example 1 before and after 5000 cycles are shown in Table 1. Based on the experimental data, it can be seen that the half-wave potential of the platinum-carbon catalyst prepared in Comparative Example 1 decreases by about 5 mV before and after 5000 cycles, and its electrochemical active area decreases by more than 20%.

[0130] As can be seen from the results in Table 1, the electrochemical active area of ​​the platinum-carbon catalyst prepared in Comparative Example 2 decreased by more than 20% after 5000 cycles. Although the electrochemical active areas of the platinum-carbon catalysts prepared in Comparative Examples 3 and 4 remained basically unchanged or decreased only slightly after 5000 cycles, their specific activity was not high.

[0131] (3) Figure 7 The results are from long-term testing of the membrane electrode assembly (MEA). MEAs can characterize the activity and long-term stability of catalysts in situ. Here, the activity and long-term stability of a commercial catalyst (JM Hispec 13100-70 wt.% Pt / C) and the platinum-carbon catalyst prepared in Example 1 were investigated. The test conditions were: temperature: 80 °C; back pressure: 2 atm; flow rate: H2 300 mL / min, O2 300 mL / min; humidity: saturated; MEA area: 2.25 × 2.25 cm; loading: anode: 0.06 mg Pt / cm². 2 Cathode 0.158 mg Pt / cm 2 Time: 40 hours; Constant current mode: 1600 mA / cm² 2 The specific experimental results are as follows: Figure 7 As shown.

[0132] The commercial platinum-carbon catalyst exhibited a voltage decrease of over 3% after 40 hours, from 0.664V to 0.640V. The platinum-carbon catalyst prepared in Example 1, however, showed a voltage decrease of less than 3% after 40 hours, from 0.689V to 0.675V. The peak power density of the platinum-carbon catalyst prepared in Example 1 before and after voltage decay was 2200 mW / cm³. 2 and 2190mW / cm 2 There was virtually no degradation. Therefore, the platinum-carbon catalyst prepared in Example 1 exhibits improved stability.

[0133] (4) Figure 8-1 Here is a high-resolution aberration electron microscope image of the platinum-carbon catalyst prepared in Example 1. Figure 8-2 Here is a high-resolution aberration electron microscope image of the platinum-carbon catalyst prepared in Comparative Example 1. Figure 8-3 High-resolution aberration-corrected electron microscope image of a commercial platinum-carbon catalyst. From Figure 8-1 , Figure 8-2 as well as Figure 8-3 It can be seen that in the platinum-carbon catalyst prepared in Example 1, the boundaries of the Pt particles are blurred, and long-term irradiation with a high-energy electron beam causes significant carbon deposition, thus proving the existence of an organic coating layer on the surface of the Pt particles. Figure 8-2 It can be seen that the platinum-carbon catalyst prepared in Comparative Example 1 has clear and full edges, and no carbon deposition was observed after long-term irradiation with a high-energy electron beam. This indicates that the surface of the platinum-carbon catalyst prepared in Comparative Example 1 does not have an organic coating layer. Figure 8-3 No organic coating layer was observed on the surface of commercial platinum-carbon catalysts.

[0134] (5) Figure 9 and Figure 10 High-resolution aberration electron microscopy image of the platinum-carbon catalyst prepared for Example 1 of the specification, showing lattice dislocations. From Figure 9 and Figure 10 It can be seen that along the normal 111 direction of the Pt crystal, a band-like distortion of the lattice is visible, and this distortion directly affects the growth direction of the crystal on the other side. A clear interface is visible, which is the boundary between the slipped and unslipped portions. This indicates that lattice dislocations exist on the surface of the Pt particles in the platinum-carbon catalyst prepared in Example 1. The reason for these lattice dislocations may be that when the complexing agent controls crystal growth, it controls and changes the surface energy of the crystal, causing the crystal to grow towards a more locally stable structure, thereby improving the stability of the prepared platinum-carbon catalyst. Statistical analysis determined that in the platinum-carbon catalyst prepared in Example 1, the proportion of platinum particles containing lattice dislocations in all tested platinum particles is more than 50%.

[0135] (6) As can be seen from the experimental data in Table 1, the platinum-carbon catalysts prepared in Examples 2 to 4 all exhibit high electrochemical stability. Furthermore, high-resolution aberration-corrected electron microscopy analysis of the platinum-carbon catalysts prepared in Examples 2 to 5 revealed the presence of an organic coating layer and surface lattice dislocations on the surface. Statistical analysis confirmed that platinum particles containing lattice dislocations accounted for more than 50% of all tested platinum particles in the platinum-carbon catalysts prepared in Examples 2 to 5. Simultaneously, in the platinum-carbon catalysts prepared in Examples 2 to 5, Pt particles were uniformly dispersed on the surface of the carbon material, with an average particle size within the range of 3-6 nm.

[0136] 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 inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

[0137] Table 1

[0138]

Claims

1. A method for preparing a platinum-carbon catalyst, wherein the platinum-carbon catalyst comprises a carbonaceous support and platinum particles supported on the carbonaceous support, wherein the platinum particles containing lattice dislocations account for more than 50% of the total number of platinum particles, the method comprising the following steps: S1. A dispersion is provided, comprising a carbonaceous material, a platinum precursor, a complexing agent, a first dispersion medium, and a second dispersion medium, wherein the first dispersion medium is ethylene glycol, the second dispersion medium is water, the complexing agent is one or both of sodium formate and sodium acetate, the volume ratio of the second dispersion medium to the first dispersion medium is 1:1-5, wherein the molar concentration of the platinum precursor is C0, the molar concentration of platinum in the liquid phase of the dispersion is C1, and C1 / C0 < 0.5; S2. Under reduction reaction conditions sufficient to reduce the platinum precursor in the dispersion to metallic platinum, the dispersion is contacted with a reducing agent to obtain a reduction reaction mixture, wherein the reducing agent contains vitamin C; S3. The reduction reaction mixture is subjected to solid-liquid separation to obtain a solid phase. The solid phase is washed and dried to obtain the platinum-carbon catalyst.

2. The method according to claim 1, wherein, The mass ratio of the platinum precursor to the complexing agent is 1:0.01-1.

3. The method according to claim 1, wherein, The mass ratio of the platinum precursor to the complexing agent is 1:0.05-0.

5.

4. The method according to claim 1, wherein, The mass ratio of the platinum precursor to the complexing agent is 1:0.1-0.

2.

5. The method according to any one of claims 1-4, wherein, In step S1, the volume ratio of the second dispersion medium to the first dispersion medium is 1:1-3.

6. The method according to claim 1, wherein, In step S1, the carbonaceous material is conductive carbon black.

7. The method according to claim 1 or 6, wherein, The specific surface area of ​​the carbonaceous material is 200-2000 m². 2 / g.

8. The method according to claim 1 or 6, wherein, The specific surface area of ​​the carbonaceous material is 250-1500 m². 2 / g.

9. The method according to claim 1, wherein, In step S1, the method for providing the dispersion includes: S1-1. Carbonaceous material, platinum precursor, first dispersion medium and second dispersion medium are dispersed by ultrasound to form a suspension. S1-2. Add the complexing agent to the suspension and disperse it using ultrasound to obtain the dispersion.

10. The method according to claim 9, wherein, In steps S1-1 and S1-2, the power of the ultrasonic wave is 50W to 3kW.

11. The method according to claim 9, wherein, In steps S1-1 and S1-2, the power of the ultrasonic wave is 1000W to 2000W.

12. The method according to claim 9, wherein, In steps S1-1 and S1-2, the dispersion time using ultrasound is from 15 minutes to 2 hours.

13. The method according to claim 9, wherein, In steps S1-1 and S1-2, the dispersion time using ultrasound is 30 minutes to 1 hour.

14. The method according to any one of claims 1-4, 6, and 9-13, wherein, C1 / C0 = 0.2 - 0.

3.

15. The method according to claim 1, wherein, In step S2, the molar ratio of the reducing agent to the platinum precursor is 5-200:1, and the platinum precursor is calculated as metallic platinum.

16. The method according to claim 1, wherein, In step S2, the molar ratio of the reducing agent to the platinum precursor is 8-100:1, and the platinum precursor is calculated as metallic platinum.

17. The method according to claim 1, wherein, In step S2, the molar ratio of the reducing agent to the platinum precursor is 10-30:1, and the platinum precursor is calculated as metallic platinum.

18. The method according to any one of claims 1 and 15-17, wherein, In step S2, the contact is performed at a temperature of 50-100°C.

19. The method according to any one of claims 1 and 15-17, wherein, In step S2, the contact is performed at a temperature of 55-90°C.

20. The method according to any one of claims 1 and 15-17, wherein, In step S2, the contact is performed at a temperature of 50-80°C.

21. The method according to any one of claims 1 and 15-17, wherein, In step S2, the duration of the contact is 2-12 hours.

22. The method according to any one of claims 1 and 15-17, wherein, In step S2, the duration of the contact is 3-8 hours.

23. The method according to claim 1, wherein, In step S3, the drying is heat drying, which is carried out at a temperature of 55-85°C.

24. The method according to claim 1, wherein, In step S3, the drying process lasts for 4-24 hours.

25. A platinum-carbon catalyst prepared by the method according to any one of claims 1-24.

26. The platinum-carbon catalyst according to claim 25, wherein, At least a portion of the surface of the platinum particles is irradiated with an electron beam to form amorphous carbon.

27. The platinum-carbon catalyst according to claim 25 or 26, wherein, The average particle size of the platinum particles is 3-6 nm.

28. The platinum-carbon catalyst according to claim 25 or 26, wherein, The electrochemical active area of ​​this platinum-carbon catalyst after 5000 cycles is ECSA. 5000 The initial electrochemical active area of ​​this platinum-carbon catalyst is ECSA. 初始 ECSA 5000 ECSA 初始 It is above 0.

9.

29. The platinum-carbon catalyst according to claim 25 or 26, wherein, The electrochemical active area of ​​this platinum-carbon catalyst after 5000 cycles is ECSA. 5000 The initial electrochemical active area of ​​this platinum-carbon catalyst is ECSA. 初始 ECSA 5000 ECSA 初始 It is 0.92-0.

99.

30. The platinum-carbon catalyst according to claim 25 or 26, wherein, The electrochemical active area of ​​this platinum-carbon catalyst after 5000 cycles is ECSA. 5000 The initial electrochemical active area of ​​this platinum-carbon catalyst is ECSA. 初始 ECSA 5000 ECSA 初始 It is 0.95-0.

99.

31. The application of the platinum-carbon catalyst according to any one of claims 25-30 in a fuel cell.

32. A hydrogen fuel cell, wherein the anode and / or cathode of the hydrogen fuel cell contain the platinum-carbon catalyst according to any one of claims 25-30.

Images