Oxygen-rich microporous carbon supported platinum catalyst, and preparation method and application thereof

Abstract

The application provides an oxygen-rich microporous carbon supported platinum catalyst and a preparation method and application thereof, and relates to the technical field of fuel cells.The catalyst comprises an oxygen-rich microporous carbon carrier and platinum nanoparticles supported on the oxygen-rich microporous carbon carrier.The oxygen-rich microporous carbon carrier contains a microporous structure, and the surface of the oxygen-rich microporous carbon carrier is attached with hydrophilic oxygen-containing functional groups.The particle size of the platinum nanoparticles is 3-5 nm.The microporous structure of the oxygen-rich microporous carbon and the hydrophilic oxygen-containing functional groups attached to the surface can effectively store water in the micropores, and the combination of the larger particle size of the platinum nanoparticles can improve the water retention capacity of the membrane electrode, improve the utilization rate of the platinum nanoparticles, and improve the catalytic activity of the catalyst, so that the catalyst still exhibits excellent output performance in the fuel cell test under low humidity conditions, is suitable for large-scale industrial production, and has wide application potential in air-cooled fuel cell stacks.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cells, in particular to an oxygen-rich microporous carbon supported platinum catalyst and a preparation method and application thereof. BACKGROUND

[0002] Proton exchange membrane fuel cell (PEMFC) is a kind of advanced energy conversion device which can convert chemical energy into electrical energy directly, and has many advantages such as high energy conversion efficiency, strong adaptability to low temperature operation environment, clean and pollution-free, and fast start.

[0003] The core component of PEMFC is membrane electrode, which can be divided into water-cooled type and air-cooled type according to different temperature control modes. In order to improve the heat dissipation capacity and heat exchange effect of the air-cooled PEMFC, a larger air flow is often required, which causes the water in the membrane electrode to be easily taken away by the air, thereby reducing the membrane wetness, and finally adversely affecting the output performance of the battery. However, the membrane electrode is the core component of PEMFC, so it is crucial to maintain the appropriate wetness of the membrane electrode under low humidity conditions (RH < 40%), which is the key to ensuring efficient proton conduction.

[0004] In the prior art, the methods for improving the water retention capacity of the membrane electrode under low humidity conditions mainly focus on the self-humidification design of the proton exchange membrane or the multi-layer structure design of the membrane electrode. These methods have problems such as poor conductivity of the introduced material, complex process of the improvement scheme, and high cost, which are not conducive to industrialization promotion. The preparation materials of the membrane electrode mainly include electrolyte membrane, catalyst and conductive material. Directly solving the water retention problem of the membrane electrode under low humidity conditions from the perspective of platinum-based catalyst can maximize the simplification of the membrane electrode design and is suitable for industrialization promotion.

[0005] At present, the common platinum-based catalyst is mainly a carbon carrier loaded with platinum nanoparticles. The traditional carbon carrier has strong hydrophobicity on the surface, which cannot effectively maintain the humidity of the reaction interface, resulting in the decrease of the water retention capacity of the membrane electrode and the weakening of the proton transport performance. Moreover, the platinum nanoparticles grown in the micropores have a long oxygen transmission path, and the platinum nanoparticles in the pores are difficult to be utilized, which leads to low utilization rate of the platinum nanoparticles and causes the decrease of the output performance of the PEMFC.

[0006] In view of this, the present application is proposed. SUMMARY

[0007] The present application provides an oxygen-rich microporous carbon supported platinum catalyst and a preparation method and application thereof, which solves the defect that the conventional platinum catalyst cannot effectively increase the water retention capacity of the membrane electrode under low humidity conditions in the prior art.

[0008] The present application provides an oxygen-rich microporous carbon supported platinum catalyst, which comprises an oxygen-rich microporous carbon carrier and platinum nanoparticles supported on the carrier, wherein the carrier contains microporous structures and has oxygen-containing functional groups connected to its surface, and the platinum nanoparticles have a particle size of 3-5 nm.

[0009] The oxygen-containing functional groups are hydrophilic groups, preferably one or more of carboxyl, hydroxyl and carbonyl groups; and the groups can form covalent bonds with carbon atoms in the carrier to be covalently bonded to the surface of the carrier, rather than in the bulk.

[0010] The catalyst of the present application can effectively store water in the microporous gaps of the carrier and delay the discharge of water from the gaps by virtue of the hydrophilic oxygen-containing functional groups connected to the surface of the carrier, thus improving the water retention capacity of the membrane electrode and the output performance of the PEMFC.

[0011] When the particle size of the platinum nanoparticles is 3-5 nm, the small-sized platinum nanoparticles can be effectively utilized, and the utilization rate of the platinum nanoparticles is improved, thus improving the output performance of the PEMFC.

[0012] According to the present application, the volume ratio of the micropores in the oxygen-rich microporous carbon carrier is 50-70%.

[0013] When the volume ratio of the micropores in the carrier is less than 50%, the water content in the micropores is small, which is not conducive to the improvement of the water retention performance of the membrane electrode; when the volume ratio is 50-70%, the water produced in the reaction can be stored in the micropores, thus effectively improving the water retention capacity of the membrane electrode; and when the volume ratio is greater than 70%, a large amount of water is stored in the micropores, which can easily cause the micropores to be blocked, thus hindering the transmission of oxygen and reducing the efficiency of the oxygen reduction reaction and the output performance of the PEMFC.

[0014] According to the present application, the oxygen content on the surface of the oxygen-rich microporous carbon carrier is 10-20%.

[0015] According to the present application, the mass content of platinum in the oxygen-rich microporous carbon supported platinum catalyst is 30wt%-70wt%.

[0016] The application also provides a preparation method of the oxygen-rich microporous carbon supported platinum catalyst as described above, comprising the following steps:

[0017] Step 1) constructing a microporous carbon material: mixing a carbon precursor and an activating agent at a mass ratio of 1:3-1:5, then performing high-temperature activation treatment, and then performing heat preservation treatment in an inert atmosphere, to obtain the microporous carbon material after cooling;

[0018] Step 2) preparing an oxygen-rich microporous carbon carrier: immersing the microporous carbon material obtained in step 1) in a concentrated nitric acid solution after washing to neutral, to perform acid oxidation treatment, and then obtaining the oxygen-rich microporous carbon carrier after filtration and drying;

[0019] Step 3) preparing platinum nanoparticles: weighing a platinum precursor and a surfactant, dissolving them in a solvent, adding a pH adjuster to adjust the pH to 8-12, and then obtaining the platinum nanoparticles after reflux heating under an argon atmosphere and centrifugation; preferably, the solvent is any one of ethylene glycol, formic acid and an aqueous sodium borohydride solution;

[0020] Step 4) catalyst preparation: mixing the oxygen-rich microporous carbon carrier obtained in step 2) and the platinum nanoparticles obtained in step 3) under ultrasonic conditions, and then performing centrifugal washing and vacuum drying.

[0021] In the preparation of the oxygen-rich microporous carbon carrier, the carbon precursor and the activating agent are first subjected to high-temperature activation treatment in an inert atmosphere to construct a microporous structure; then the obtained microporous carbon material is washed, and the surface is modified by acid oxidation treatment in a nitric acid system, so as to connect the hydrophilic oxygen-containing functional groups to the surface of the oxygen-rich microporous carbon carrier, effectively increase the content of the hydrophilic oxygen-containing functional groups such as carboxyl, hydroxyl and carbonyl on the surface of the oxygen-rich microporous carbon carrier, improve the hydrophilicity of the carrier, delay the process of water discharge from the microporous pores, and improve the water retention capacity of the membrane electrode.

[0022] In the preparation of the platinum nanoparticles, a reduction method is adopted, and the platinum precursor, the surfactant and the pH adjuster are subjected to reflux heating reaction under the protection of argon, so that the particle size of the platinum nanoparticles can be effectively controlled under the joint action of the surfactant and the pH adjuster, the particle size of the formed platinum nanoparticles is 3-5 nm, and the utilization rate of the platinum nanoparticles is improved.

[0023] In step 4), the platinum nanoparticles are uniformly dispersed and loaded on the oxygen-rich microporous carbon carrier by ultrasonic treatment, and the size is uniform, so that the oxygen-rich microporous carbon carrier is loaded with platinum nanoparticles with large particle size, which can not only improve the catalytic activity of the catalyst, but also improve the water retention capacity of the catalyst under low humidity conditions, thereby improving the water retention capacity of the membrane electrode and having better output performance.

[0024] According to the preparation method of the oxygen-rich microporous carbon supported platinum catalyst provided by the application, in step 1), the temperature rising procedure of the high-temperature activation treatment is heating to 800-1000 ℃ at a temperature rising rate of 5-8 ℃ / min, and the holding treatment time is 1-120 min.

[0025] Preferably, the activator is at least one of potassium hydroxide and sodium hydroxide.

[0026] Preferably, the mass ratio of the carbon precursor and the activator is 1:4, the temperature rising procedure of the high-temperature activation treatment is heating to 900 ℃ at a temperature rising rate of 5-8 ℃ / min, and the holding treatment time is 120 min.

[0027] According to the preparation method of the oxygen-rich microporous carbon supported platinum catalyst provided by the application, the carbon precursor is any one of Vulcan XC72R, Ketjen Black EC300J, Ketjen Black ECP600JD and Black Pearls 2000, and the activator is at least one of potassium hydroxide and sodium hydroxide.

[0028] According to the preparation method of the oxygen-rich microporous carbon supported platinum catalyst provided by the application, the acid oxidation treatment temperature is 80-120 ℃, and the acid oxidation treatment time is 2-6 h.

[0029] Preferably, the acid oxidation treatment temperature is 100 ℃, and the acid oxidation treatment time is 4 h.

[0030] According to the preparation method of the oxygen-rich microporous carbon supported platinum catalyst provided by the application, the concentration of the concentrated nitric acid is 1-6 mol / L.

[0031] According to the preparation method of the oxygen-rich microporous carbon supported platinum catalyst provided by the application, the molar ratio of the platinum precursor to the surfactant is 1:1-1:0.2.

[0032] Preferably, the molar ratio of the platinum precursor to the surfactant is 1:0.5.

[0033] According to the preparation method of the oxygen-rich microporous carbon supported platinum catalyst provided by the application, the platinum precursor is any one of chloroplatinic acid, platinum chloride and platinum acetylacetonate.

[0034] According to the preparation method of the oxygen-rich microporous carbon supported platinum catalyst provided by the application, the surfactant is any one of polyvinylpyrrolidone, oleic acid oleylamine, cetyltrimethylammonium bromide and dodecyltrimethylammonium bromide.

[0035] Preferably, the surfactant is polyvinylpyrrolidone.

[0036] According to the application, the temperature of the reflux heating in step 3) is 120-160℃, and the heating time is 1-10h.

[0037] Preferably, the temperature of the reflux heating is 160℃, and the heating time is 4h.

[0038] The application also provides the use of the oxygen-rich microporous carbon supported platinum catalyst as described above, which can be used for preparing a hydrogen fuel cell.

[0039] Preferably, the oxygen-rich microporous carbon supported platinum catalyst is used for preparing a hydrogen fuel cell operating under low humidity conditions.

[0040] The oxygen-rich microporous carbon supported platinum catalyst, the preparation method and the use thereof provided by the application, by using oxygen-rich microporous carbon as a carrier and loading large-particle-size platinum nanoparticles on the carrier, the microporous structure of the oxygen-rich microporous carbon carrier and the hydrophilic oxygen-containing functional groups connected on the surface thereof can effectively store water in the micropores, and in combination with the large-particle-size platinum nanoparticles, the water retention capacity of the membrane electrode is improved, the utilization rate of the platinum nanoparticles is improved, the catalytic activity of the catalyst is improved, the catalyst still exhibits excellent output performance in the fuel cell test under low humidity conditions, is suitable for large-scale industrial production, and has wide application potential in air-cooled fuel cell stacks. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the application or prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort.

[0042] Figure 1 XRD patterns of the catalysts in Example 1 and Comparative Example 4;

[0043] Figure 2 Polarization performance diagrams of the catalysts in Example 1, Example 2 and Example 3 in the hydrogen-air fuel cell test without humidification;

[0044] Figure 3 Polarization performance diagrams of the catalysts in Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4 in the hydrogen-air fuel cell test without humidification. DETAILED DESCRIPTION

[0045] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in conjunction with the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0046] The present application will be described below in conjunction with Figures 1-3 A kind of oxygen-rich microporous carbon supported platinum catalyst suitable for low humidity conditions and its preparation method and application are described.

[0047] Unless specific techniques or conditions are specified in the embodiments, the techniques or conditions described in the literature in the art or according to the product instructions are used. Unless the manufacturer of the reagents or instruments is specified, they are all conventional products that can be purchased through regular channels.

[0048] Example 1

[0049] A method for preparing an oxygen-rich microporous carbon supported platinum catalyst, comprising the following steps:

[0050] Step 1) Constructing microporous carbon material: Black Pearls 2000 and KOH were mixed in a mass ratio of 1:4, then placed in a corundum crucible, heated to 900℃ in a tube furnace for high-temperature activation, and treated in an inert atmosphere for 120 min. After natural cooling, the activated microporous carbon material was obtained.

[0051] Step 2) Preparation of oxygen-rich microporous carbon carrier: The microporous carbon material obtained in step 1) was washed with hydrochloric acid and deionized water to neutral, then immersed in a concentrated nitric acid solution with a concentration of 3 mol / L, and acid oxidation reaction was carried out under oil bath conditions. The acid oxidation reaction temperature was 100℃, and the treatment time was 4 h. After filtration and drying, the oxygen-rich microporous carbon carrier was obtained.

[0052] Step 3) Preparation of platinum nanoparticles: chloroplatinic acid and polyvinylpyrrolidone were dissolved in ethylene glycol in a molar ratio of 1:0.5 and transferred into a three-necked flask with reflux device. 0.1 mol / L NaOH solution was used as pH adjuster to adjust the pH value of the solution to 10. Under argon protection, reflux heating reaction was carried out at 160℃ for 4 h, and then centrifugation was carried out to obtain platinum nanoparticles.

[0053] Step 4) Catalyst preparation: the oxygen-rich microporous carbon support obtained in step 2) and the platinum nanoparticles obtained in step 3) are mixed, treated under the condition of ultrasonic power 200 W for 60 min, washed by centrifugation, and dried at 60°C under vacuum to obtain the catalyst; the catalyst comprises the oxygen-rich microporous carbon support and the platinum nanoparticles supported on the oxygen-rich microporous carbon support, and the oxygen-rich microporous carbon support is a porous carbon material containing microporous structures and surface oxygen-containing functional groups. The volume fraction of micropores in the oxygen-rich microporous carbon support is 58%, and the surface oxygen content is 15%. The particle size of the platinum nanoparticles is 4 nm, and the mass content of platinum in the catalyst is 50 wt%.

[0054] Example 2

[0055] A method for preparing an oxygen-rich microporous carbon supported platinum catalyst, the steps of which are basically the same as those of Example 1, except that in step 1), the mass ratio of Black Pearls 2000 to KOH is replaced by 1:3; and in step 4), the mass content of platinum is controlled to be 70 wt%.

[0056] Example 3

[0057] A method for preparing an oxygen-rich microporous carbon supported platinum catalyst, the steps of which are basically the same as those of Example 1, except that in step 2), the temperature of the acid oxidation reaction is replaced by 80°C.

[0058] Example 4

[0059] A method for preparing an oxygen-rich microporous carbon supported platinum catalyst, the steps of which are basically the same as those of Example 1, except that in step 1), the mass ratio of Black Pearls 2000 to KOH is replaced by 1:5; and in step 4), the mass content of platinum is controlled to be 30 wt%.

[0060] Example 5

[0061] A method for preparing an oxygen-rich microporous carbon supported platinum catalyst, the steps of which are basically the same as those of Example 1, except that in step 2), the temperature of the acid oxidation reaction is replaced by 120°C.

[0062] The particle size and mass content of platinum in the oxygen-rich microporous carbon supported platinum catalysts prepared by Examples 1-5 and the performance of the oxygen-rich microporous carbon support are shown in Table 1:

[0063] Table 1 Particle size and mass content of platinum in the oxygen-rich microporous carbon supported platinum catalysts prepared by Examples 1-5 and the performance of the oxygen-rich microporous carbon support

[0064]

[0065] The detection method of the oxygen content on the surface of the oxygen-rich microporous carbon carrier is X-ray photoelectron spectroscopy (XPS). The determination method of the mass content of platinum is inductively coupled plasma atomic emission spectrometer (ICP-AES). For specific determination method, refer to Chen T, Qiu C, Zhang X, et al. An ultrasmall ordered high-entropy intermetallic with multiple active sites for the oxygen reduction reaction[J]. Journal of the American Chemical Society, 2023, 146(1): 1174-1184.

[0066] Comparative Example 1

[0067] A preparation method of an oxygen-rich microporous carbon supported platinum catalyst, the steps of which are basically the same as those of Example 1, except that step 1) of subjecting Black Pearls 2000 to KOH high-temperature activation treatment and step 2) of directly subjecting Black Pearls 2000 to acid oxidation treatment are not included.

[0068] Comparative Example 2

[0069] A preparation method of an oxygen-rich microporous carbon supported platinum catalyst, the steps of which are basically the same as those of Example 1, except that step 2) of subjecting the microporous carbon material to acid oxidation treatment is not included.

[0070] Comparative Example 3

[0071] A preparation method of an oxygen-rich microporous carbon supported platinum catalyst, the steps of which are basically the same as those of Example 1, except that steps 1) and 2) are not included, and Black Pearls 2000 is neither subjected to KOH high-temperature activation treatment nor subjected to acid oxidation treatment.

[0072] Comparative Example 4

[0073] A method for preparing an oxygen-rich microporous carbon supported platinum catalyst, the steps of which are basically the same as those of Example 1, except that in step 3), an impregnation reduction method is used for preparation, and the specific operation is to mix chloroplatinic acid hydrate and deionized water in a mass ratio of 1:1 by ultrasonic mixing into a chloroplatinic acid solution, and then add Black Pearls 2000 which has been treated by KOH activation and HNO3 oxidation in turn and has the same mass of Pt as in the solution. After further ultrasonic mixing, pre-freeze at-15℃ for 1 hour in a freeze dryer, then reduce the temperature to-40℃, and then heat to 70℃ at a heating rate of 10℃ / min, and keep vacuum throughout the process. Take out the sublimation dried material and transfer it to a tube furnace, pass in 10vol% H2 / N2 atmosphere, heat to 200℃ and keep for 2 hours, and after natural cooling, obtain the catalyst.

[0074] Test Example 1

[0075] In this test example, the carriers obtained in the process of preparing the oxygen-rich microporous carbon supported platinum catalyst of Examples 1-3 and Comparative Examples 1-3 are subjected to N2 adsorption, and the specific surface area and the proportion of micropores and mesopores of the carriers are determined by the Brunauer-Emmett-Teller (BET) method and the pore size analysis based on the Quenched Solid Density Functional Theory (QSDFT), and the results are shown in Table 2.

[0076] Table 2 Performance test table of carbon carriers prepared in Examples 1-3 and Comparative Examples 1-3

[0077]

[0078] As can be seen from Table 2, by comparing Examples 1-3, it can be seen that the oxygen-rich microporous carbon carrier obtained by using Black Pearls 2000 and KOH in a mass ratio of 1:4 for activation and when the acid oxidation temperature is 100℃ has the highest specific surface area and micropore proportion; compared with Comparative Examples 1-3, the specific surface area and micropore proportion of the oxygen-rich microporous carbon carrier corresponding to Example 1 are both significantly higher than those of Comparative Examples 1-3, which shows that by high-temperature activation treatment and acid oxidation treatment of the carbon precursor, the specific surface area of the oxygen-rich microporous carbon carrier can be effectively increased, the proportion of micropores can be increased, the hydrophilicity of the carrier can be effectively improved, the water in the micropore pores can be delayed from being discharged, and the water retention capacity of the membrane electrode can be improved.

[0079] Test Example 2

[0080] In this test example, the oxygen-rich microporous carbon supported platinum catalyst prepared in Example 1 and Comparative Example 4 is subjected to X-ray diffraction test, and the XRD pattern is as shown in Figure 1As shown, the crystal phase (platinum) of the catalyst prepared by different preparation methods matched with the standard card Pt (JCPDS 04-0802), and the grain size of Example 1 and Comparative Example 4 was calculated according to the Scherrer formula to be 5.0 nm and 2.8 nm respectively, indicating that when the catalyst was prepared in Example 1, the chloroplatinic acid was refluxed and heated with the surfactant and the pH regulator, and under the joint action of the surfactant and the pH regulator, larger size platinum nanoparticles could be generated, thereby improving the utilization rate of platinum in the catalyst.

[0081] Test Example 3

[0082] The performance of the hydrogen-air fuel cell of the catalyst prepared in Examples 1-3 and Comparative Examples 1-4 under low humidity conditions was tested in this test example. The test method was as follows: the examples and comparative examples were used as cathode catalysts, and the Pt metal loading was controlled to be 0.3 mgPt / cm 2 ; the anode used commercial 40% Pt / C (Johnson Matthey HiSPEC4000) as the catalyst, and the anode Pt metal loading was 0.1 mgPt / cm 2 ; the cell temperature was 50°C, hydrogen was fed into the anode, and air was fed into the cathode, the metering ratio was 1.3:2.5, the back pressure was 0.05 MPa, and neither the anode nor the cathode was humidified; after the cell was activated and the steady-state performance was stable, the polarization curve test was carried out, the test was gradually decreased from 1V-0.3V, the change of current density was tested and recorded. The results are shown in Figure 2 and Figure 3 .

[0083] As can be seen from Figure 2 , the power density corresponding to the current density of 1 ampere per square centimeter of Example 1, Example 2 and Example 3 was 0.716, 0.692 and 0.678 watt per square centimeter respectively, and the maximum power density was 1.15, 1.1 and 1.06 watt per square centimeter respectively.

[0084] As can be seen from Figure 3 , the power density corresponding to the current density of 1 ampere per square centimeter of Comparative Example 1 without activation treatment and Comparative Example 2 without acid oxidation treatment was only 0.62 and 0.63 watt per square centimeter respectively, and the maximum power density was only 0.94 and 0.91 watt per square centimeter respectively, which were significantly lower than Example 1.

[0085] The power density corresponding to the current density of 1 ampere per square centimeter of the conventional carbon carrier loaded Pt catalyst (comparative example 3) and the catalyst prepared by the impregnation reduction method (comparative example 4, platinum particle size is 2.8 nm) is only 0.605 and 0.66 watt per square centimeter, respectively, and the maximum power density is only 0.744 and 0.88 watt per square centimeter, respectively, which are obviously lower than that of example 1.

[0086] Test example 4: Experimental study on the influence of the volume ratio of micropores on the performance of the hydrogen-air fuel cell of the oxygen-rich microporous carbon loaded platinum catalyst under low humidity conditions

[0087] This test example studies the influence of different volume ratios of micropores in the oxygen-rich microporous carbon carrier on the performance of the catalyst in the hydrogen-air fuel cell under low humidity conditions, and the test method of the cell performance is the same as that of test example 3, and the results are shown in table 3:

[0088] Table 3: Influence of the volume ratio of micropores on the performance of the catalyst in the hydrogen-air fuel cell under low humidity conditions

[0089]

[0090] As can be seen from the above table, with the increase of the volume ratio of micropores, the cell formation shows a trend of first rising and then falling, indicating that the volume ratio of micropores has an influence on the performance of the fuel cell, and when the volume ratio of micropores is 50-70%, the performance of the cell can reach a better effect.

[0091] In summary of the above test analysis, the catalyst loaded with platinum nanoparticles of larger particle size by the oxygen-rich microporous carbon carrier can be prepared by the method of the present application (examples 1-5), and when the volume ratio of micropores in the oxygen-rich microporous carbon carrier is 50-70% and the particle size of the loaded platinum nanoparticles is 3-5 nm, the oxygen-rich microporous carbon loaded platinum catalyst can effectively alleviate the performance decay caused by the weak water retention capacity of the membrane electrode under low humidity conditions, and can effectively improve the output performance of the hydrogen-air fuel cell under low humidity conditions.

[0092] Finally, it should be pointed out that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: the technical solutions recorded in the foregoing examples can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An oxygen-rich microporous carbon supported platinum catalyst, characterized in that, The oxygen-rich microporous carbon supported platinum catalyst comprises an oxygen-rich microporous carbon carrier and platinum nanoparticles supported on the oxygen-rich microporous carbon carrier, the oxygen-rich microporous carbon carrier contains a microporous structure, and a hydrophilic oxygen-containing functional group is connected to the surface of the oxygen-rich microporous carbon carrier, and the particle size of the platinum nanoparticles is 3-5 nm; the volume fraction of micropores in the oxygen-rich microporous carbon carrier is 50-70%; The preparation method of the oxygen-rich microporous carbon supported platinum catalyst comprises the following steps: Step 1) constructing a microporous carbon material: mixing a carbon precursor and an activating agent at a mass ratio of 1:3-1:5, then performing activation treatment, and then performing heat preservation treatment in an inert atmosphere, and then obtaining a microporous carbon material after cooling; Step 2) preparing an oxygen-rich microporous carbon carrier: immersing the microporous carbon material obtained in step 1) in a concentrated nitric acid solution after washing to neutral, performing acid oxidation treatment, filtering and drying to obtain an oxygen-rich microporous carbon carrier; Step 3) preparing platinum nanoparticles: weighing a platinum precursor and a surfactant, dissolving them in a solvent, adding a pH adjuster to adjust the pH to 8-12, refluxing and heating under an argon atmosphere, and then centrifuging to obtain platinum nanoparticles; Step 4) catalyst preparation: mixing the oxygen-rich microporous carbon carrier obtained in step 2) and the platinum nanoparticles obtained in step 3) under ultrasonic conditions, washing by centrifugation, and then vacuum drying.

2. The oxygen-rich microporous carbon supported platinum catalyst according to claim 1, characterized in that, The oxygen content on the surface of the oxygen-rich microporous carbon carrier is 10-20%.

3. The oxygen-rich microporous carbon supported platinum catalyst according to claim 1 or 2, characterized in that, The mass content of platinum in the oxygen-rich microporous carbon supported platinum catalyst is 30wt%-70wt%.

4. A process for the preparation of an oxygen enriched microporous carbon supported platinum catalyst according to any one of claims 1 to 3, characterized in that, comprises the following steps: Step 1) constructing a microporous carbon material: mixing a carbon precursor and an activating agent at a mass ratio of 1:3-1:5, then performing activation treatment, and then performing heat preservation treatment in an inert atmosphere, and then obtaining a microporous carbon material after cooling; Step 2) preparing an oxygen-rich microporous carbon carrier: immersing the microporous carbon material obtained in step 1) in a concentrated nitric acid solution after washing to neutral, performing acid oxidation treatment, filtering and drying to obtain an oxygen-rich microporous carbon carrier; Step 3) preparing platinum nanoparticles: weighing a platinum precursor and a surfactant, dissolving them in a solvent, adding a pH adjuster to adjust the pH to 8-12, refluxing and heating under an argon atmosphere, and then centrifuging to obtain platinum nanoparticles; Step 4) catalyst preparation: mixing the oxygen-rich microporous carbon carrier obtained in step 2) and the platinum nanoparticles obtained in step 3) under ultrasonic conditions, washing by centrifugation, and then vacuum drying.

5. The method for preparing an oxygen-enriched microporous carbon-supported platinum catalyst according to claim 4, characterized in that, In step 1), the temperature rising program of the activation treatment is heating to 800-1000℃ at a temperature rising rate of 5-8℃ / min, and the heat preservation time is 1-120 min; and / or, the activating agent is at least one of potassium hydroxide and sodium hydroxide.

6. The method for preparing an oxygen-enriched microporous carbon-supported platinum catalyst according to claim 4, characterized in that, The temperature of the acid oxidation treatment is 80-120℃, and the acid oxidation treatment time is 2-6 h.

7. A method of preparing an oxygen-rich microporous carbon supported platinum catalyst according to any one of claims 4-6, characterized in that, The molar ratio of the platinum precursor to the surfactant is 1:1-1:0.

2.

8. The method for preparing an oxygen-enriched microporous carbon-supported platinum catalyst according to claim 7, characterized in that, The surfactant is any one of polyvinylpyrrolidone, oleic acid oleylamine, cetyltrimethylammonium bromide, and dodecyltrimethylammonium bromide.

9. A method of preparing an oxygen-rich microporous carbon supported platinum catalyst according to any one of claims 4-6, characterized in that, In step 3), the temperature of the reflux heating is 120-160℃, and the reflux heating time is 1-10 h.

10. Use of the oxygen-enriched microporous carbon supported platinum catalyst according to any one of claims 1 to 3, characterized in that, The application of the oxygen-rich microporous carbon supported platinum catalyst in a hydrogen fuel cell.

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