Platinum-carbon catalyst for proton exchange membrane fuel cell and synthesis process of platinum-carbon catalyst

Abstract

The invention relates to the technical field of fuel cells, in particular to a platinum-carbon catalyst for a proton exchange membrane fuel cell and a synthesis process thereof, and the synthesis process comprises the following steps: S1, weighing chloroplatinic acid and polyol, and preparing a solution H; s2, weighing sodium hydroxide, absolute ethyl alcohol and / or pure water to prepare a solution I; s3, weighing a carbon carrier, fully mixing the carbon carrier with polyol, then sequentially pouring the solution H and the solution I, and fully mixing to form mixed slurry P; s4, sequentially carrying out pre-dispersion treatment and crushing treatment on the mixed slurry P to enable the particle size of suspended matters in the mixed slurry P to be within a certain range, and then carrying out ice-bath stirring; and S5, carrying out water bath heating, carrying out heat preservation after the water bath temperature rises to 95-100 DEG C, then carrying out ice bath cooling, adding a strong acid solution, and standing. And S6, carrying out suction filtration, and then carrying out drying and grinding treatment to obtain the platinum-carbon catalyst. The process is simple to operate, high in thermal stability and lower in reaction temperature, and can be used for large-scale production.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a platinum-carbon catalyst for proton exchange membrane fuel cells and a synthesis process thereof. Background Art

[0002] With the rapid development of human society, large-scale industrialization has led to economic prosperity and technological progress. However, this process has also brought about many environmental and ecological problems. At the same time, with the intensification of environmental pollution, climate change, and the shortage of resources and energy, people are becoming more and more aware of environmental protection, and the development and utilization of clean energy has become the focus of current attention. With its environmentally friendly, sustainable and renewable characteristics, clean energy provides an effective way to solve the energy crisis, reduce environmental pollution, and respond to climate change. Moreover, with the advancement of science and technology and the development of society, clean energy will play an increasingly important role in the future.

[0003] Hydrogen energy, as a renewable energy source that is pollution-free to the environment, has important development value. Fuel cells are one of the most commercially promising hydrogen energy terminal devices. The main reaction site of hydrogen energy is the anode of the fuel cell. The platinum-carbon catalyst of the fuel cell can catalyze hydrogen into hydrogen ions, which are then transferred to the cathode through the proton exchange membrane to combine with oxygen to form water and generate electricity. At the same time, platinum-carbon catalysts are still one of the main platinum-carbon catalysts used in fuel cells.

[0004] At present, the production of fuel cell platinum carbon catalysts has initially entered commercialization; the synthesis processes commonly used for fuel cell platinum carbon catalysts are mainly microwave method and oil bath method; among them, microwave method is used by most companies. However, when the microwave method is used to prepare fuel cell platinum carbon catalysts, although it has the advantages of fast preparation reaction process and short heating time; however, when this method is used to mass produce fuel cell platinum carbon catalysts, its synthesis process is complicated, the reaction temperature is in the range of 115℃-135℃, the reaction temperature is relatively high, and the requirements for equipment are also very harsh, which makes the equipment cost and equipment use and maintenance cost high, which leads to high production cost; and due to the volume limitation of the heating equipment, the production capacity and performance consistency of the platinum carbon catalyst product will also be affected. The oil bath method, because of its poor thermal stability during the heating process, is dangerous to operate; and due to the limitations of equipment and instruments, it cannot be mass-produced and has a small scope of application. Therefore, it is urgent to develop a process suitable for mass production of fuel cell platinum carbon catalysts.

[0005] The present invention provides a platinum-carbon catalyst for a proton exchange membrane fuel cell and a synthesis process thereof, so as to solve the problems existing in the prior art of the existing synthesis process, such as relatively high reaction temperature, complex process, strict requirements on equipment, low yield, and inability to mass produce. Summary of the invention

[0006] The purpose of the present invention is to provide a platinum-carbon catalyst for proton exchange membrane fuel cells and a synthesis process thereof, so as to solve the problems existing in the prior art, such as high reaction temperature, complex process, strict requirements on equipment, low yield, and inability to mass produce.

[0007] The technical scheme of the present invention is: a synthesis process of a platinum-carbon catalyst for a proton exchange membrane fuel cell, wherein, calculated by mass percentage, the formula of the platinum-carbon catalyst includes 0.3%-0.5% of a carbon carrier, 1%-3% of chloroplatinic acid, 65%-75% of a polyol, 18%-30% of anhydrous ethanol, 0%-10% of pure water, 0.5%-1% of sodium hydroxide, and 2%-5% of concentrated hydrochloric acid;

[0008] The platinum-carbon catalyst is synthesized by using the formula, and the synthesis process includes the following steps:

[0009] S1. Weigh chloroplatinic acid and polyol in proportion, and divide the weighed polyol into two parts; put the weighed chloroplatinic acid into a reaction container, and slowly add one part of the polyol into the reaction container, ultrasonicate for 5-15 minutes, and then stir for 2-4 hours to completely dissolve the chloroplatinic acid in the polyol, and prepare solution H; the polyol is one of ethylene glycol and butanediol or a mixture of two; S2. Weigh sodium hydroxide, anhydrous ethanol and / or pure water in proportion, and dissolve the weighed sodium hydroxide in anhydrous ethanol and / or pure water, and stir for 5-30 minutes to completely dissolve the sodium hydroxide, so as to form solution I;

[0010] S3, weighing a carbon carrier according to a proportion and subjecting the carbon carrier to a high-temperature graphitization treatment, placing the treated carbon carrier in a reaction container, first adding another portion of the polyol remaining in step S1 into the reaction container, stirring for 5-10 minutes to fully mix the carbon carrier and the polyol, then sequentially pouring all of solution H and solution I into the reaction container, stirring for 5-15 minutes, and fully mixing to form a mixed slurry P;

[0011] S4, placing the reaction container containing the mixed slurry P in an ice bath, performing pre-dispersion treatment and crushing treatment on the mixed slurry P in sequence, so that the particle size of the suspended matter in the mixed slurry P is within a certain range, and then stirring in an ice bath for 6-10 hours;

[0012] S5. After the ice bath stirring is completed, the reaction vessel is moved to a water bath for water bath heating. After the water bath temperature rises to 95-100° C., it is kept warm for 15-30 minutes, and then cooled in an ice bath. After it cools to room temperature, the strong acid solution is slowly added to the reaction vessel and stirred for 0.5-1.5 hours, and then allowed to stand for 2-6 hours;

[0013] S6. After standing, filter and wash with pure water for 5-7 times to obtain a platinum-carbon catalyst solid, and then dry and grind the platinum-carbon catalyst solid obtained by filtration to obtain a platinum-carbon catalyst.

[0014] Preferably, the carbon carrier is any one of carbon black, mesoporous carbon and carbon aerogel.

[0015] Preferably, the high-temperature graphitization treatment comprises the following steps: a. placing the weighed carbon carrier into a high-temperature furnace, introducing nitrogen into the high-temperature furnace, raising the temperature in the high-temperature furnace from room temperature to 650-750° C., controlling the heating rate within the range of 1-3° C. / min, and then keeping the temperature for 15-60 min;

[0016] b. After the insulation is completed, the temperature in the high-temperature furnace is increased from 650-750℃ to 1450-1550℃, and the heating rate is controlled within the range of 1-4℃ / min, and then the insulation is carried out for 15-60min. c. After the insulation is completed, the temperature in the high-temperature furnace is increased from 1450-1550℃ to 1850-1950℃, and the heating rate is controlled within the range of 1-3℃ / min, and then the insulation is carried out for 30-90min. d. After the insulation is completed, the high-temperature furnace is naturally cooled to room temperature, and then the carbon carrier is taken out.

[0017] Preferably, the mass ratio of pure water to anhydrous ethanol weighed in step S2 is (0-2):(4.5-7).

[0018] Preferably,

[0019] The instrument used for the pre-dispersion treatment is an emulsifying shearing machine; the treatment time of the pre-dispersion treatment is 30-60 minutes;

[0020] The instrument used for the pulverization process is a cell crusher; the processing time of the pre-dispersion process is 10-30 minutes.

[0021] Preferably, the particle size of the suspension is D50: 900nm-D50: 1000nm.

[0022] Preferably, the strong acid solution in step S5 is concentrated hydrochloric acid or concentrated nitric acid.

[0023] The present invention also provides a platinum-carbon catalyst for a proton exchange membrane fuel cell, and the platinum-carbon catalyst is synthesized by using the above-mentioned synthesis process.

[0024] Compared with the prior art, the advantages of the present invention are:

[0025] (1) The present invention provides a platinum-carbon catalyst for proton exchange membrane fuel cells and a synthesis process thereof. Compared with traditional methods such as oil bath heating and microwave heating, the operation of the synthesis process is simpler, the thermal stability is high, and the reaction temperature of the synthesized platinum-carbon catalyst is lower, which effectively reduces the operational risk during the synthesis process and helps to reduce the equipment requirements of the synthesis process, so that the synthesis process can be produced in large quantities with high production capacity and good consistency of the synthesized platinum-carbon catalyst; and solves the problems of the existing synthesis process in the prior art, such as high reaction temperature, complex process, stringent requirements on equipment, low output, and inability to produce in large quantities.

[0026] (2) The present invention provides a platinum-carbon catalyst for a proton exchange membrane fuel cell and a synthesis process thereof. The synthesis process can adjust the reaction temperature of the synthesized platinum-carbon catalyst by adjusting the amount of anhydrous ethanol and pure water used; thereby reducing the operational risk during the synthesis of the platinum-carbon catalyst and reducing the requirements for the quality and performance of the heating equipment; at the same time, increasing the amount of anhydrous ethanol used can also improve the performance of the proton exchange membrane fuel cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0028] Figure 1 The performance test results of the proton exchange membrane fuel cell described in Example 1 of the present invention;

[0029] Figure 2 The performance test results of the proton exchange membrane fuel cell described in Example 2 of the present invention; DETAILED DESCRIPTION

[0030] The present invention is further described in detail below in conjunction with specific embodiments:

[0031] A synthesis process of a platinum-carbon catalyst for a proton exchange membrane fuel cell. The formula of the platinum-carbon catalyst used in the synthesis process comprises, by mass percentage, 0.3%-0.5% of a carbon carrier, 1%-3% of chloroplatinic acid, 65%-75% of a polyol, 18%-30% of anhydrous ethanol, 0%-10% of pure water, 0.5%-1% of sodium hydroxide, and 2%-5% of concentrated hydrochloric acid; wherein the chloroplatinic acid is preferably chloroplatinic acid hexahydrate (chemical formula: H2PtCl6·6H2O);

[0032] The synthesis process specifically comprises the following steps:

[0033] S1. Weigh chloroplatinic acid in proportion and put the weighed chloroplatinic acid into a reaction container; weigh polyol in proportion and divide the weighed polyol into two parts; then slowly add one part of the polyol into the reaction container containing chloroplatinic acid, and ultrasonicate for 5-15 minutes to completely dissolve the chloroplatinic acid in the polyol, that is, use half of the amount of polyol to dissolve the chloroplatinic acid; then, place the reaction container on a magnetic stirrer and stir for 2-4 hours to prepare solution H. Wherein, the polyol is one or a combination of two of ethylene glycol and butanediol; ethylene glycol and butanediol can also be replaced by other polyols, such as hexanediol, neopentyl glycol, glycerol, etc.; the ultrasonication time and stirring time can be appropriately shortened or extended according to the amount of solution H to be configured, so as to achieve the effect of completely dissolving chloroplatinic acid in the polyol.

[0034] S2, weigh sodium hydroxide, anhydrous ethanol and / or pure water in proportion, and dissolve the weighed sodium hydroxide in anhydrous ethanol and / or pure water, stir for 5-30min, so that the sodium hydroxide is completely dissolved to form solution I; wherein, sodium hydroxide can be replaced by strong alkaline salts such as potassium hydroxide; the mass ratio of the weighed pure water to anhydrous ethanol is (0-2): (4.5-7). Using anhydrous ethanol and pure water to prepare solution I, not only can inorganic bases such as sodium hydroxide be fully dissolved; it can also promote better dispersion of solution I in the process of preparing mixed slurry P; at the same time, the reaction temperature of the synthetic platinum-carbon catalyst can also be reduced.

[0035] S3, weigh the carbon carrier in proportion and perform high-temperature graphitization treatment on the carbon carrier, put the treated carbon carrier into a reaction vessel, first add half of the remaining amount of polyol in step S1 into the reaction vessel, stir for 5-10min, fully mix the carbon carrier and the polyol, then pour the solution H prepared in step S1 and the solution I prepared in step S2 into the reaction vessel in turn, stir to fully mix the solution H, solution I and the mixed solution of the carbon carrier and the polyol to form a mixed slurry P. Wherein, in the present invention, the carbon carrier used is X carbon carrier, and the carbon carrier needs high-temperature graphitization treatment before use. Commonly used X carbon carriers include carbon black, mesoporous carbon, graphene, etc.; in the present invention, the carbon carrier used preferably uses carbon black or mesoporous carbon such as Vulcan XC-72R and Ketjen black.

[0036] The method for high-temperature graphitization of the carbon carrier specifically includes the following steps: a. After placing the carbon carrier in a high-temperature furnace, nitrogen is first introduced into the high-temperature furnace, and the ventilation time is controlled within 5-15 minutes; after the nitrogen ventilation process is completed, the high-temperature furnace is heated to increase the temperature in the high-temperature furnace, and the heating rate is controlled within the range of 1-3°C / min. When the temperature in the high-temperature furnace rises to 650-750°C, it is kept warm for 15-60 minutes; b. After the insulation is completed, Heat up again, raise the temperature in the high-temperature furnace from 650-750℃ to 1450-1550℃, control the heating rate at 1-4℃ / min, and then keep warm for 15-60min; c. After the insulation is completed, raise the temperature in the high-temperature furnace from 1450-1550℃ to 1850-1950℃, control the heating rate at 1-3℃ / min, and then keep warm for 30-90min; d. After the insulation is completed, cool the high-temperature furnace naturally to room temperature, and then take out the treated carbon carrier. The purpose of this treatment process is to purify the impurities in the carbon carrier and graphitize it to improve the corrosion resistance and conductivity of the carbon carrier. However, during the heating treatment, the insulation time needs to be reasonably controlled. Long-term high-temperature treatment may lead to a decrease in the specific surface area of ​​the carbon carrier, which in turn affects the active area of ​​the platinum-carbon catalyst.

[0037] S4, put the reaction container containing the mixed slurry P into an ice bath, and perform pre-dispersion treatment and crushing treatment on the mixed slurry P in turn, so that the particle size of the suspended matter is within a certain range, and then stir in an ice bath for 6-10h. In the present invention, an emulsifying shearing machine is used to pre-disperse the mixed slurry P, and the treatment time of the pre-dispersion treatment is 30-60min; a cell crusher is used to crush the mixed slurry P, and the crushing treatment time is 10-30min. In the present invention, the purpose of the pre-dispersion treatment and crushing treatment is to regulate the particle size of the suspended matter to avoid the large particles of the suspended matter, which causes the chloroplatinic acid, sodium hydroxide, carbon carrier, etc. in the mixed slurry P to be unable to fully combine and convert into a platinum-carbon catalyst during the subsequent heating process, affecting the yield of the platinum-carbon catalyst. The time of the pre-dispersion treatment and the duration of the crushing treatment can be appropriately shortened or extended according to the particle size of the detected suspended matter, so that the particle size of the suspended matter can reach a reasonable range. In the present invention, the particle size of the suspended matter is in the range of D50: 900nm-D50: 1000nm.

[0038] After S5 and ice bath stirring are completed, the reaction vessel is moved to a water bath for water bath heating, and the water temperature in the water bath is raised to 95-100°C, and then kept warm for 15-30min, that is, the water bath temperature is 95-100°C, and the water bath reaction time is 15-30min; then an ice bath is performed to cool down, and after it drops to room temperature, a strong acid solution is slowly added to the reaction vessel and stirred for 0.5-1.5h, and allowed to stand for 2-6h. Among them, the strong acid solution is preferably a strong acid such as concentrated hydrochloric acid, concentrated sulfuric acid, and concentrated nitric acid; but since concentrated sulfuric acid has a certain catalyst toxicity, it will make the platinum carbon catalyst lose activity, and the present invention preferably uses concentrated hydrochloric acid or concentrated nitric acid.

[0039] After S6 and standing, suction filtration is performed, and pure water is used to wash 5-7 times to obtain a platinum-carbon catalyst solid, and then the filtered platinum-carbon catalyst solid is dried and ground to obtain a platinum-carbon catalyst. The effect of repeatedly rinsing with clear water during suction filtration is to avoid coating impurities, other metal ions, anhydrous ethanol solvents, etc. in the synthesized platinum-carbon catalyst particles, so that the synthesized platinum-carbon catalyst has a higher purity and the platinum-carbon catalyst has good dispersibility.

[0040] Example 1

[0041] S1. Weigh 3 g of chloroplatinic acid hexahydrate and 160 g of ethylene glycol, and divide the 160 g of ethylene glycol into two equal parts; put the weighed chloroplatinic acid into a reaction container, and slowly add 80 g of ethylene glycol into the reaction container containing the chloroplatinic acid; then, put the reaction container into an ultrasonicator for ultrasonication; after ultrasonication for 10 minutes, stir the reaction container on a magnetic stirrer for 3 hours to completely dissolve the chloroplatinic acid in the ethylene glycol, and prepare solution H1 for standby use.

[0042] S2. Weigh 2 g of sodium hydroxide, 20 g of pure water and 50 g of anhydrous ethanol, put the weighed 2 g of sodium hydroxide into a reaction container, and slowly add the weighed 20 g of pure water and 50 g of anhydrous ethanol to the container containing the sodium hydroxide in sequence; then place the reaction container on a magnetic stirrer and stir for 30 min to completely dissolve the sodium hydroxide in the pure water and anhydrous ethanol, and prepare I1.

[0043] S3. Weigh 5 g of carbon carrier (model: Vulcan XC-72R), put the weighed carbon carrier into a high-temperature furnace, first introduce nitrogen into the high-temperature furnace, and the time of introducing nitrogen is 10 minutes; then heat the high-temperature furnace, raise the temperature in the high-temperature furnace from room temperature to 700°C, the heating rate is 2°C / min, and then keep it warm for 30 minutes; secondly, raise the temperature in the high-temperature furnace from 700°C to 1500°C, the heating rate is 3°C / min, and then keep it warm for 30 minutes; finally, raise the temperature in the high-temperature furnace from 1500°C to 1900°C, the heating rate is 2°C / min, and then keep it warm for 60 minutes; after the insulation is completed, the high-temperature furnace is naturally cooled to room temperature, and then taken out of the high-temperature furnace and weighed to obtain 4.8 g of high-temperature graphitized carbon carrier.

[0044] Weigh 0.9 g of the carbon carrier treated with high temperature graphitization and put it into a reaction container. Slowly add another 80 g of ethylene glycol in step S1 into the reaction container containing the carbon carrier and stir for 10 min to fully mix the carbon carrier and the polyol. Then, add the solution H1 prepared in step S1 and the solution I1 prepared in step S2 into the reaction container in turn and stir to fully mix them to form a mixed slurry P1.

[0045] S4. Place the reaction container containing the mixed slurry P1 in an ice bath, perform shear treatment for 40 min and crushing treatment for 20 min on the mixed slurry P1, so that the particle size of the suspended matter in the mixed slurry P1 is D50: 950 nm, and then stir for 8 h in an ice bath.

[0046] S5. After the ice bath stirring is completed, the reaction vessel is moved to a water bath for water bath heating; the temperature in the water bath is slowly increased until the water in the water bath boils, and the mixed slurry P1 in the reaction vessel is stirred with a magnetic stirring rod while the temperature is increased, which helps to make the mixed slurry P1 heated evenly; when the water in the water bath boils, the temperature of the solution in the reaction vessel is monitored to be 95-98° C., at this time, a reaction of synthesizing the platinum-carbon catalyst occurs in the reaction vessel; after 20 minutes of water bath reaction, the reaction vessel is transferred to an ice bath for cooling; when the temperature of the solution in the reaction vessel drops to room temperature, 6 ml of concentrated hydrochloric acid is slowly added to the reaction vessel, and stirred for 1 hour, and then allowed to stand for 4 hours. In other embodiments, microwave heating, oil bath heating, etc. may be used instead of the water bath heating in this embodiment; since the synthesis process provided by the present invention has a relatively low reaction temperature, when heating is performed by oil bath heating, it is not necessary to raise the temperature of the oil bath pot to 110°C-140°C, which can greatly reduce the operational risks during the oil bath heating process; similarly, when heating is performed by microwave heating, it is not necessary to set the temperature of the microwave equipment to above 115°C, which can effectively reduce the requirements for the quality of the microwave oven equipment.

[0047] S6. After standing, perform suction filtration, wash the solid with pure water 5 times during the suction filtration process to obtain a platinum-carbon catalyst solid, and then dry and grind the filtered platinum-carbon catalyst solid to obtain a platinum-carbon catalyst, A1.

[0048] The catalyst synthesized above is applied to a proton exchange membrane fuel cell, and the polarization curve of the proton exchange membrane fuel cell is detected; Figure 1 As shown in the curve of the relationship between electrode potential and current density, when the current density is 2.2A / cm 2 , the voltage is 0.646V.

[0049] Example 2

[0050] S1. Weigh 3 g of chloroplatinic acid hexahydrate and 160 g of ethylene glycol, and divide the 160 g of ethylene glycol into two parts; put the weighed chloroplatinic acid into a reaction container, and slowly add 80 g of ethylene glycol into the reaction container containing chloroplatinic acid; then, put the reaction container into an ultrasonicator for ultrasonication; after ultrasonication for 10 minutes, stir the reaction container on a magnetic stirrer for 3 hours to completely dissolve the chloroplatinic acid in the ethylene glycol, and prepare solution H2 for standby use.

[0051] S2. Weigh 2 g of sodium hydroxide, 10 g of pure water and 60 g of anhydrous ethanol, put the weighed 2 g of sodium hydroxide into a reaction container, and slowly add the weighed 10 g of pure water and 60 g of anhydrous ethanol to the container containing the sodium hydroxide in sequence; then place the reaction container on a magnetic stirrer and stir for 30 min to completely dissolve the sodium hydroxide in the pure water and anhydrous ethanol, and prepare I2.

[0052] S3, weigh 0.9 g of the above-mentioned high-temperature graphitized carbon carrier; put it into a reaction container, slowly add another 80 g of ethylene glycol in step S1 into the reaction container containing the carbon carrier, stir for 10 minutes, so that the carbon carrier and the polyol are fully mixed; then, add the H2 prepared in step S1 and the I2 prepared in step S2 into the reaction container in sequence, stir to make them fully mixed, and form a mixed slurry P2.

[0053] S4. Place the reaction container containing the mixed slurry P2 in an ice bath, and perform shear treatment for 40 minutes and crushing treatment for 20 minutes on the mixed slurry P2 in sequence, so that the particle size of the suspended matter in the mixed slurry P2 is D50: 950 nm, and then stir for 8 hours under ice bath conditions.

[0054] S5, after the ice bath stirring is completed, the reaction vessel is moved to a water bath for water bath heating; the temperature in the water bath is slowly increased until the water in the water bath boils, and the mixed slurry P2 in the reaction vessel is stirred with a magnetic stirring rod while heating; before the water in the water bath boils, a reaction of synthesizing a platinum-carbon catalyst in the reaction vessel is monitored, and at this time the water temperature in the water bath is 98°C, and the temperature of the solution in the reaction vessel is 92-96°C; after the water in the water bath boils, a reaction of synthesizing a platinum-carbon catalyst continues to occur in the reaction vessel; after 20 minutes of water bath reaction, the reaction vessel is transferred to an ice bath for cooling; when the temperature of the solution in the reaction vessel drops to room temperature, 6 ml of concentrated hydrochloric acid is slowly added to the reaction vessel, and stirred for 1 hour, and then allowed to stand for 4 hours;

[0055] S6. After standing, perform suction filtration, wash the solid with pure water 5 times during the suction filtration process to obtain a platinum-carbon catalyst solid, and then dry and grind the filtered platinum-carbon catalyst solid to obtain a platinum-carbon catalyst, A2.

[0056] The catalyst synthesized above is applied to a proton exchange membrane fuel cell, and the polarization curve of the proton exchange membrane fuel cell is detected; Figure 2 As shown in the curve of the relationship between electrode potential and current density, when the current density is 2.2A / cm 2 , the voltage is 0.649V.

[0057] It can be seen from Example 1 and Example 2 that, in the synthesis process provided by the present invention, the synthesis temperature of the platinum-carbon catalyst is within the range of 90-100°C; and it can be seen from Example 1 compared with Example 2 that in Example 2, the amount of pure water is reduced when preparing solution I2, and the amount of anhydrous ethanol is increased, and the reaction temperature when synthesizing the platinum-carbon catalyst is significantly lower than the reaction temperature when synthesizing the platinum-carbon catalyst in Example 1, which further illustrates that increasing the amount of anhydrous ethanol can effectively reduce the reaction temperature of the synthesized platinum-carbon catalyst; at the same time, the platinum-carbon catalysts synthesized in Example 1 and Example 2 are respectively applied to a proton exchange membrane fuel cell, and the polarization curve of the battery is detected. According to the fact that the higher the voltage value is when the current density is a certain value, the better, the platinum-carbon catalyst synthesized in Example 2 is applied to the proton exchange membrane fuel cell. Compared with the platinum-carbon catalyst synthesized in Example 2, the battery using the platinum-carbon catalyst synthesized in Example 2 has better performance, which further illustrates that the performance of the proton exchange membrane fuel cell can be improved by reducing the amount of pure water and increasing the amount of anhydrous ethanol in the process of synthesizing the platinum-carbon catalyst. In summary, increasing the amount of anhydrous ethanol can not only reduce the reaction temperature of synthesizing platinum-carbon catalysts, but also help improve battery performance.

[0058] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the scope of protection of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention.

Claims

1. A synthesis process of a platinum-carbon catalyst for a proton exchange membrane fuel cell, characterized in that: Calculated by mass percentage, the formula of the platinum-carbon catalyst includes 0.3%-0.5% of a carbon carrier, 1%-3% of chloroplatinic acid, 65%-75% of a polyol, 18%-30% of anhydrous ethanol, 0%-10% of pure water, 0.5%-1% of sodium hydroxide, and 2%-5% of concentrated hydrochloric acid; The platinum-carbon catalyst is synthesized by using the formula, and the synthesis process includes the following steps: S1. Weigh chloroplatinic acid and polyol in proportion, and divide the weighed polyol into two parts; put the weighed chloroplatinic acid into a reaction container, and slowly add one part of the polyol into the reaction container, ultrasonicate for 5-15 minutes, and then stir for 2-4 hours to completely dissolve the chloroplatinic acid in the polyol to prepare a solution H; the polyol is one of ethylene glycol and butanediol or a mixture of the two; S2, weighing sodium hydroxide, anhydrous ethanol and / or pure water in proportion, and dissolving the weighed sodium hydroxide in the anhydrous ethanol and / or pure water, stirring for 5-30 min to completely dissolve the sodium hydroxide, to form a solution I; S3, weighing a carbon carrier according to a proportion and subjecting the carbon carrier to a high-temperature graphitization treatment, placing the treated carbon carrier in a reaction container, first adding another portion of the polyol remaining in step S1 into the reaction container, stirring for 5-10 minutes to fully mix the carbon carrier and the polyol, then sequentially pouring all of solution H and solution I into the reaction container, stirring for 5-15 minutes, and fully mixing to form a mixed slurry P; S4, placing the reaction container containing the mixed slurry P in an ice bath, performing pre-dispersion treatment and crushing treatment on the mixed slurry P in sequence, and then stirring in an ice bath for 6-10 hours; S5. After the ice bath stirring is completed, the reaction vessel is moved to a water bath for water bath heating. After the water bath temperature rises to 95-100° C., it is kept warm for 15-30 minutes, and then cooled in an ice bath. After it cools to room temperature, the strong acid solution is slowly added to the reaction vessel and stirred for 0.5-1.5 hours, and then allowed to stand for 2-6 hours; S6. After standing, filter and wash with pure water for 5-7 times to obtain a platinum-carbon catalyst solid, and then dry and grind the platinum-carbon catalyst solid obtained by filtration to obtain a platinum-carbon catalyst.

2. The synthesis process of a platinum-carbon catalyst for a proton exchange membrane fuel cell according to claim 1, characterized in that: The carbon carrier is any one of carbon black, mesoporous carbon and graphene.

3. The synthesis process of a platinum-carbon catalyst for a proton exchange membrane fuel cell according to claim 2, characterized in that: The high temperature graphitization treatment comprises the following steps: a. Put the weighed carbon carrier into a high-temperature furnace, introduce nitrogen into the high-temperature furnace, raise the temperature in the high-temperature furnace from room temperature to 650-750°C, control the heating rate within the range of 1-3°C / min, and then keep it warm for 15-60min; b. After the insulation is completed, the temperature in the high-temperature furnace is raised from 650-750℃ to 1450-1550℃, and the heating rate is controlled within the range of 1-4℃ / min, and then the temperature is kept for 15-60min; c. After the insulation is completed, the temperature in the high-temperature furnace is raised from 1450-1550℃ to 1850-1950℃, and the heating rate is controlled within the range of 1-3℃ / min, and then the temperature is kept for 30-90min; d. After the heat preservation is completed, the high temperature furnace is naturally cooled to room temperature, and then the carbon carrier is taken out.

4. The synthesis process of a platinum-carbon catalyst for a proton exchange membrane fuel cell according to claim 1, characterized in that: The mass ratio of pure water to anhydrous ethanol weighed in step S2 is (0-2):(4.5-7).

5. The synthesis process of a platinum-carbon catalyst for a proton exchange membrane fuel cell according to claim 1, characterized in that: The instrument used for the pre-dispersion treatment is an emulsifying shearing machine; the treatment time of the pre-dispersion treatment is 30-60 minutes; The instrument used for the pulverization process is a cell crusher; the processing time of the pre-dispersion process is 10-30 minutes.

6. The synthesis process of a platinum-carbon catalyst for a proton exchange membrane fuel cell according to claim 1, characterized in that: The particle size of the suspended matter is D50: 900nm-D50: 1000nm.

7. The synthesis process of a platinum-carbon catalyst for a proton exchange membrane fuel cell according to claim 1, characterized in that: In step S5, the strong acid solution is concentrated hydrochloric acid or concentrated nitric acid.

8. A platinum-carbon catalyst for a proton exchange membrane fuel cell, characterized in that: The compound is synthesized by the synthesis process described in any one of claims 1 to 7.

Images