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

Abstract

The application relates to the field of fuel cell technology, and particularly relates to a platinum-carbon catalyst for a proton exchange membrane fuel cell and a synthesis process thereof, which comprises the following steps: S1, weighing chloroplatinic acid and polyhydric alcohol to prepare solution H; S2, weighing sodium hydroxide, anhydrous ethanol and / or pure water to prepare solution I; S3, weighing a carbon carrier and fully mixing the carbon carrier with the polyhydric alcohol, then sequentially pouring the solution H and the solution I into the carbon carrier, fully mixing to form mixed slurry P; S4, sequentially performing pre-dispersion treatment and crushing treatment on the mixed slurry P, so that the particle size of suspended matters in the mixed slurry P is within a certain range, then performing ice bath stirring; S5, performing water bath heating, keeping the water bath temperature at 95-100 DEG C after the temperature is increased to 95-100 DEG C, then performing ice bath cooling, and adding a strong acid solution and then standing; S6, performing suction filtration, then performing drying and grinding treatment to obtain the platinum-carbon catalyst. The process is simple in operation, high in thermal stability, lower in reaction temperature, and capable of mass production.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fuel cell technology, in particular to a platinum-carbon catalyst for proton exchange membrane fuel cells and a synthesis process thereof. BACKGROUND

[0002] With the rapid development of human society, large-scale industrialization leads to economic prosperity and technological progress, and people's awareness of environmental protection is becoming stronger. The development and utilization of clean energy has become the focus of attention. Clean energy, with its environmental protection, sustainability and renewable characteristics, provides an effective way to solve energy crisis, reduce environmental pollution and cope with climate change. With the progress 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 does not pollute the environment, has important development value. Fuel cells are one of the most promising hydrogen energy terminal devices for commercial applications. The main reaction site of hydrogen energy is the anode of the fuel cell, and the platinum-carbon catalyst of the fuel cell can catalyze hydrogen gas into hydrogen ions. Hydrogen ions are then transferred to the cathode using a proton exchange membrane to combine with oxygen to generate water and produce electrical energy. At the same time, platinum-carbon catalyst is still one of the main platinum-carbon catalysts used in fuel cells.

[0004] Currently, the production of fuel cell platinum-carbon catalysts has initially entered commercialization. The synthesis process commonly used for fuel cell platinum-carbon catalysts is mainly microwave method and oil bath method. Among them, the microwave method is applied by most companies. However, when using the microwave method to prepare fuel cell platinum-carbon catalysts, although it has the advantages of fast preparation reaction process and short heating time required, the synthesis process is complex, the reaction temperature is in the range of 115℃-135℃, the reaction temperature is relatively high, the requirements for equipment are very harsh, which results in high equipment cost and high cost of equipment use and maintenance, thereby leading to high production cost. And due to the limitation of the volume of the heating equipment, the production capacity and the consistency of the performance of the platinum-carbon catalyst product will also be affected. The oil bath method has poor thermal stability during heating and is dangerous to operate. Due to the limitations of equipment and instruments, it cannot be mass-produced, and its application range is small. Therefore, there is an urgent need to develop a process suitable for mass production of fuel cell platinum-carbon catalysts.

[0005] The present application provides a platinum-carbon catalyst for proton exchange membrane fuel cells and a synthesis process thereof, to solve the problems of high reaction temperature, complex process, harsh requirements for equipment, low yield and inability to mass-produce in the prior art. SUMMARY

[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 of the existing synthesis process, such as relatively high reaction temperature, complex process, stringent requirements on equipment, low yield, and inability to mass produce.

[0007] The technical solution 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 using the formula, and the synthesis process includes the following steps:

[0009] S1. Weigh chloroplatinic acid and a polyol in proportion, and divide the weighed polyol into two equal parts; place the weighed chloroplatinic acid in a reaction vessel, and slowly add one part of the polyol to the reaction vessel, sonicate for 5-15 minutes, and then stir for 2-4 hours to completely dissolve the chloroplatinic acid in the polyol, to form a solution H; the polyol is one or a mixture of ethylene glycol and butanediol; 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, to form a solution I;

[0010] S3. Weigh a carbon support in proportion and perform a high-temperature graphitization treatment on the carbon support. Place the treated carbon support in a reaction vessel. First, add the remaining portion of the polyol from step S1 to the reaction vessel and stir for 5-10 minutes to fully mix the carbon support and the polyol. Then, pour all of solution H and solution I into the reaction vessel in sequence and stir for 5-15 minutes to fully mix to form a mixed slurry P.

[0011] S4. Place the reaction vessel containing the mixed slurry P in an ice bath, perform 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 stir 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 is raised to 95-100°C, it is kept warm for 15-30 minutes, and then cooled in an ice bath. After cooling 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 the standing is completed, filtration is carried out, and the platinum carbon catalyst solid is obtained by washing 5-7 times with pure water, and then the platinum carbon catalyst solid obtained by filtration is dried and ground to obtain the platinum carbon catalyst.

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

[0015] Preferably, the high-temperature graphitization treatment comprises the following steps: a, the weighed carbon carrier is placed in a high-temperature furnace, nitrogen is introduced into the high-temperature furnace, the temperature in the high-temperature furnace is increased from room temperature to 650-750 DEG C, the temperature increasing speed is controlled within the range of 1-3 DEG C / min, and then the temperature is kept for 15-60 min;

[0016] b, after the temperature keeping is completed, the temperature in the high-temperature furnace is increased from 650-750 DEG C to 1450-1550 DEG C, the temperature increasing speed is controlled within the range of 1-4 DEG C / min, and then the temperature is kept for 15-60 min, c, after the temperature keeping is completed, the temperature in the high-temperature furnace is increased from 1450-1550 DEG C to 1850-1950 DEG C, the temperature increasing speed is controlled within the range of 1-3 DEG C / min, and then the temperature is kept for 30-90 min; d, after the temperature keeping 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 the pure water to the anhydrous ethanol weighed in step S2 is (0-2):(4.5-7).

[0018] Preferably,

[0019] The instrument used in the pre-dispersion treatment is an emulsifying shearing machine; and the treatment time of the pre-dispersion treatment is 30-60 min.

[0020] The instrument used in the pulverization treatment is a cell crusher; and the treatment time of the pre-dispersion treatment is 10-30 min.

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

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

[0023] The application further provides a platinum carbon catalyst for a proton exchange membrane fuel cell, which is synthesized by using the above synthesis process.

[0024] Compared with the prior art, the application has the following advantages:

[0025] (1) The platinum-carbon catalyst for a proton exchange membrane fuel cell and the synthesis process thereof provided by the present application have the advantages that, compared with traditional oil bath heating, microwave heating and the like, the synthesis process is simpler to operate, has high thermal stability, has a lower reaction temperature for synthesizing the platinum-carbon catalyst, effectively reduces the operation risk in the synthesis process, helps to reduce the requirements of the synthesis process on equipment, enables the synthesis process to be mass-produced, has a higher production capacity, and the synthesized platinum-carbon catalyst has good consistency; and the problems of high reaction temperature, complex process, harsh requirements on equipment, low yield and inability to mass-produce in the prior art are solved.

[0026] (2) The platinum-carbon catalyst for a proton exchange membrane fuel cell and the synthesis process thereof provided by the present application can adjust the reaction temperature for synthesizing the platinum-carbon catalyst by adjusting the amount of anhydrous ethanol and pure water, thereby reducing the operation risk in the synthesis process of the platinum-carbon catalyst, reducing the requirements on the quality and performance of the heating equipment, and increasing the amount of anhydrous ethanol to improve the performance of the proton exchange membrane fuel cell. BRIEF DESCRIPTION OF DRAWINGS

[0027] The present application will be further described below in combination with the drawings and examples:

[0028] Figure 1 The performance detection results of the proton exchange membrane fuel cell described in Example 1 of the present application are as follows:

[0029] Figure 2 The performance detection results of the proton exchange membrane fuel cell described in Example 2 of the present application are as follows: DETAILED DESCRIPTION

[0030] The content of the present application will be further described in detail below in combination with specific examples:

[0031] The synthesis process of a platinum-carbon catalyst for a proton exchange membrane fuel cell comprises the following steps:

[0032] The synthesis process of a platinum-carbon catalyst for a proton exchange membrane fuel cell comprises the following steps:

[0033] S1, weigh the chloroplatinic acid according to the proportion and put it into the reaction container; weigh the polyol according to the proportion and divide it into two equal parts; then slowly add one of the polyols to the reaction container containing the chloroplatinic acid, and ultrasonic for 5-15 min, so that the chloroplatinic acid is completely dissolved in the polyol, that is, half the amount of polyol is used to dissolve the chloroplatinic acid; then, the reaction container is placed on a magnetic stirrer and stirred for 2-4 hours to prepare solution H. In the present application, the polyol is one of ethylene glycol and butanediol or a combination of the two; the ethylene glycol and butanediol can also be replaced by other polyols, such as hexanediol, neopentyl glycol, glycerol, etc.; the ultrasonic time and stirring time can be appropriately shortened or lengthened according to the amount of solution H to be prepared, as long as the chloroplatinic acid is completely dissolved in the polyol.

[0034] S2, weigh the sodium hydroxide, anhydrous ethanol and / or pure water according to the proportion, dissolve the weighed sodium hydroxide in anhydrous ethanol and / or pure water, and stir for 5-30 min to completely dissolve the sodium hydroxide to form solution I; in the present application, the sodium hydroxide can be replaced by potassium hydroxide and other strong alkaline salts; 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 fully dissolve inorganic bases such as sodium hydroxide, but also can promote the dispersion of solution I during the preparation of mixed slurry P, and at the same time, can reduce the reaction temperature of the synthesis of platinum-carbon catalyst.

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

[0036] The treatment method for high-temperature graphitization treatment of the carbon carrier specifically comprises the following steps: a, after the carbon carrier is placed in the high-temperature furnace, nitrogen is first introduced into the high-temperature furnace, and the gas introduction time is controlled to be 5-15 min; after the nitrogen introduction process is completed, the high-temperature furnace is heated to increase the temperature in the high-temperature furnace, and the temperature increasing speed is controlled to be in the range of 1-3 ℃ / min, and when the temperature in the high-temperature furnace is increased to 650-750 ℃, the temperature is kept for 15-60 min; b, after the temperature keeping is completed, the temperature in the high-temperature furnace is increased from 650-750 ℃ to 1450-1550 ℃, the temperature increasing speed is controlled to be 1-4 ℃ / min, and then the temperature is kept for 15-60 min; c, after the temperature keeping is completed, the temperature in the high-temperature furnace is increased from 1450-1550 ℃ to 1850-1950 ℃, the temperature increasing speed is controlled to be 1-3 ℃ / min, and then the temperature is kept for 30-90 min; d, after the temperature keeping is completed, the high-temperature furnace is naturally cooled to room temperature, and then the treated carbon carrier is taken out. The purpose of the treatment process is to purify the impurities in the carbon carrier and simultaneously perform graphitization treatment on the carbon carrier to improve the corrosion resistance and electrical conductivity of the carbon carrier. However, in the process of temperature increasing treatment, the temperature keeping time needs to be reasonably controlled, and if the high-temperature treatment time is too long, the specific surface area of the carbon carrier may be reduced, thereby affecting the active area of the platinum-carbon catalyst.

[0037] S4, the reaction container containing the mixed slurry P is placed in an ice bath, and the mixed slurry P is sequentially subjected to pre-dispersion treatment and crushing treatment to make the particle size of the suspension within a certain range, and then subjected to ice bath stirring for 6-10 h. In the present application, the mixed slurry P is subjected to pre-dispersion treatment by using an emulsifying shearing machine, and the pre-dispersion treatment time is 30-60 min; the mixed slurry P is subjected to crushing treatment by using a cell crusher, and the crushing treatment time is 10-30 min. In the present application, the purpose of pre-dispersion treatment and crushing treatment is to regulate the particle size of the suspension, so as to avoid that the particles of the suspension are too large, and the chloroplatinic acid, sodium hydroxide and carbon carrier in the mixed slurry P cannot be fully combined and converted into platinum-carbon catalyst in the subsequent heating process, thereby affecting the yield of the platinum-carbon catalyst. The pre-dispersion treatment time and the crushing treatment time can be appropriately shortened or lengthened according to the detected particle size of the suspension, and the particle size of the suspension can be made to be within a reasonable range. In the present application, the particle size of the suspension is within the range of D50: 900 nm-D50: 1000 nm.

[0038] S5, after the ice bath stirring is completed, the reaction container is removed to the water bath boiler to carry out water bath heating, the water temperature in the water bath boiler is raised to 95-100℃, and then the water bath temperature is kept for 15-30 minutes, that is, the water bath temperature is 95-100℃, and the water bath reaction time is 15-30 minutes; then the ice bath cooling is carried out, and after the temperature is reduced to room temperature, the strong acid solution is slowly added to the reaction container and stirred for 0.5-1.5 hours, and then the reaction container is placed for 2-6 hours. The strong acid solution is preferably concentrated hydrochloric acid, concentrated sulfuric acid, concentrated nitric acid and the like; but since the concentrated sulfuric acid has a certain catalyst toxicity, it will make the platinum carbon catalyst lose activity, and the concentrated hydrochloric acid or the concentrated nitric acid is preferably used in the application.

[0039] S6, after the standing is completed, the filtration is carried out, and the pure water is used for washing 5-7 times to obtain the platinum carbon catalyst solid, and then the platinum carbon catalyst solid obtained by filtration is dried and ground to obtain the platinum carbon catalyst. The effect of washing with water in the filtration process is to avoid the coating of impurities, other metal ions and anhydrous ethanol solvent in the synthesized platinum carbon catalyst particles, so that the synthesized platinum carbon catalyst has high purity, and the platinum carbon catalyst has good dispersity.

[0040] Example 1

[0041] S1, 3g of chloroplatinic acid hexahydrate and 160g of ethylene glycol are weighed, and the 160g of ethylene glycol is evenly divided into two parts; the weighed chloroplatinic acid is placed in a reaction container, and 80g of ethylene glycol is slowly added to the reaction container containing the chloroplatinic acid; then the reaction container is placed in an ultrasonic device for ultrasonic treatment; after ultrasonic treatment for 10 minutes, the reaction container is stirred on a magnetic stirrer for 3 hours, so that the chloroplatinic acid is completely dissolved in the ethylene glycol to prepare a solution H1, which is ready for use.

[0042] S2, 2g of sodium hydroxide, 20g of pure water and 50g of anhydrous ethanol are weighed, the weighed 2g of sodium hydroxide is placed in a reaction container, and the weighed 20g of pure water and 50g of anhydrous ethanol are slowly added to the container containing the sodium hydroxide; then the reaction container is placed on a magnetic stirrer and stirred for 30 minutes, so that the sodium hydroxide is completely dissolved in the pure water and the anhydrous ethanol to 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 nitrogen introduction time is 10 min; then heat the high-temperature furnace, and the temperature in the high-temperature furnace is increased from room temperature to 700℃ at a rate of 2℃ / min, and then kept for 30 min; secondly, the temperature in the high-temperature furnace is increased from 700℃ to 1500℃ at a rate of 3℃ / min, and then kept for 30 min; finally, the temperature in the high-temperature furnace is increased from 1500℃ to 1900℃ at a rate of 2℃ / min, and then kept for 60 min; after the heat preservation is completed, the high-temperature furnace is naturally cooled to room temperature, then taken out and weighed, and 4.8 g of high-temperature graphitized carbon carrier is obtained.

[0044] Weigh 0.9 g of the above high-temperature graphitized carbon carrier; 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, stir for 10 min, and mix the carbon carrier and the polyhydric alcohol thoroughly; then add the solution H1 prepared in step S1 and the solution I1 prepared in step S2 into the reaction container in turn, stir to mix thoroughly, and form a mixed slurry P1.

[0045] S4, put the reaction container containing the mixed slurry P1 into an ice bath, and sequentially shear the mixed slurry P1 for 40 min and crush it for 20 min, so that the particle size of the suspended matter in the mixed slurry P1 is D50: 950 nm, and then stir in the ice bath for 8 h.

[0046] S5, after the ice bath stirring is completed, move the reaction container to a water bath for water bath heating; slowly increase the temperature in the water bath until the water in the water bath boils, and at the same time, use a magnetic stirring rod to stir the mixed slurry P1 in the reaction container, which helps to heat the mixed slurry P1 uniformly; when the water in the water bath boils, the temperature of the solution in the reaction container is monitored to be 95-98℃, at which time the reaction of synthesizing platinum-carbon catalyst occurs in the reaction container; after water bath reaction for 20 min, move the reaction container to an ice bath for cooling; when the temperature of the solution in the reaction container is reduced to room temperature, slowly add 6 ml of concentrated hydrochloric acid into the reaction container, and stir for 1 h, and then stand for 4 hours. In other embodiments, microwave heating, oil bath heating and the like can be used instead of water bath heating in this embodiment; since the synthesis process provided by the present application has a low reaction temperature, when oil bath heating is used, the temperature of the oil bath does not need to be increased to 110℃-140℃, which can greatly reduce the operation risk in the oil bath heating process; similarly, when microwave heating is used, the temperature of the microwave equipment does not need to be set to more than 115℃, which can effectively reduce the requirement for the quality of the microwave oven equipment.

[0047] S6. After standing, perform suction filtration. During the filtration process, wash the solid with pure water 5 times to obtain a platinum-carbon catalyst solid. 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 When , 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 equal parts; place the weighed chloroplatinic acid in a reaction vessel, and slowly add 80 g of the ethylene glycol portion to the reaction vessel containing the chloroplatinic acid; then, place the reaction vessel in an ultrasonicator for ultrasonication; after ultrasonication for 10 minutes, stir the reaction vessel on a magnetic stirrer for 3 hours to completely dissolve the chloroplatinic acid in the ethylene glycol, to prepare solution H2, which is ready for use.

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

[0052] S3. Weigh 0.9 g of the carbon support treated with high-temperature graphitization above; place it in a reaction vessel; slowly add another 80 g of ethylene glycol prepared in step S1 to the reaction vessel containing the carbon support; stir for 10 minutes to fully mix the carbon support and the polyol; then, sequentially add the H2 prepared in step S1 and the I2 prepared in step S2 to the reaction vessel; stir to fully mix them, and form a mixed slurry P2.

[0053] S4. Place the reaction vessel containing the mixed slurry P2 in an ice bath, and perform shearing treatment on the mixed slurry P2 for 40 minutes and crushing treatment for 20 minutes 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] After S5 and ice bath stirring were completed, the reaction vessel was moved to a water bath and heated in a water bath; the temperature in the water bath was slowly increased until the water in the water bath boiled, and the mixed slurry P2 in the reaction vessel was stirred with a magnetic stirring bar while heating; before the water in the water bath boiled, a reaction of synthesizing a platinum-carbon catalyst in the reaction vessel was monitored, and at this time, the water temperature in the water bath was 98°C, and the temperature of the solution in the reaction vessel was 92-96°C; after the water in the water bath boiled, a reaction of synthesizing a platinum-carbon catalyst continued to occur in the reaction vessel; after 20 minutes of water bath reaction, the reaction vessel was transferred to an ice bath for cooling; after the temperature of the solution in the reaction vessel dropped to room temperature, 6 ml concentrated hydrochloric acid was 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. During the filtration process, wash the solid with pure water 5 times to obtain a platinum-carbon catalyst solid. 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 When , the voltage is 0.649V.

[0057] It can be seen from Examples 1 and 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 compared with Example 2, it can be seen that in Example 2, the amount of pure water is reduced when preparing solution I 2, and the amount of anhydrous ethanol is increased. 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 Examples 1 and 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. This further illustrates that reducing the amount of pure water and increasing the amount of anhydrous ethanol in the process of synthesizing the platinum-carbon catalyst can also improve the performance of its proton exchange membrane fuel cell. 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 examples are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application. For those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application, therefore, no matter from which point of view, the examples should be regarded as exemplary and non-limiting, the scope of the present application is defined by the appended claims rather than the above description, therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application.

Claims

1. A process for synthesizing 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% carbon carrier, 1%-3% chloroplatinic acid, 65%-75% polyol, 18%-30% anhydrous ethanol, 0%-10% pure water, 0.5%-1% sodium hydroxide, and 2%-5% concentrated hydrochloric acid; The platinum-carbon catalyst is synthesized using the formula, and the synthesis process includes the following steps: S1. Weigh chloroplatinic acid and a polyol in proportion, and divide the weighed polyol into two equal parts; place the weighed chloroplatinic acid in a reaction vessel, and slowly add one part of the polyol to the reaction vessel, sonicate for 5-15 minutes, and then stir for 2-4 hours to completely dissolve the chloroplatinic acid in the polyol, to form a solution H; the polyol is one of ethylene glycol and butanediol, or a mixture of the two; S2. Weigh sodium hydroxide, anhydrous ethanol and / or pure water in proportion, dissolve the weighed sodium hydroxide in the anhydrous ethanol and / or pure water, and stir for 5-30 minutes to completely dissolve the sodium hydroxide to form solution I; S3. Weigh a carbon support in proportion and perform a high-temperature graphitization treatment on the carbon support. Place the treated carbon support in a reaction vessel. First, add the remaining portion of the polyol from step S1 to the reaction vessel and stir for 5-10 minutes to fully mix the carbon support and the polyol. Then, pour solution H and solution I into the reaction vessel in sequence and stir for 5-15 minutes to fully mix to form a mixed slurry P. S4. Place the reaction vessel containing the mixed slurry P in an ice bath, perform pre-dispersion treatment and crushing treatment on the mixed slurry P in sequence, and then stir 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 is raised 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 process for synthesizing a platinum-carbon catalyst for a proton exchange membrane fuel cell according to claim 1, wherein: 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. Place the weighed carbon support into a high-temperature furnace and introduce nitrogen into the furnace. Raise the temperature in the furnace from room temperature to 650-750°C at a rate of 1-3°C / min, then keep the temperature for 15-60 minutes. b. After the insulation is completed, increase the temperature in the high-temperature furnace from 650-750℃ to 1450-1550℃, and control the heating rate within the range of 1-4℃ / min, and then keep it warm for 15-60min; c. After the insulation is completed, increase the temperature in the high-temperature furnace from 1450-1550℃ to 1850-1950℃, and control the heating rate within the range of 1-3℃ / min, and then keep it warm for 30-90min; d. After the heat preservation is completed, the high-temperature furnace is naturally cooled to room temperature, and then the carbon support 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 process for synthesizing a platinum-carbon catalyst for a proton exchange membrane fuel cell according to claim 1, wherein: 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 comminution treatment is a cell crusher; the treatment time of the pre-dispersion treatment is 10-30 minutes.

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

7. The process for synthesizing 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 according to any one of claims 1 to 7.

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