Preparation method of inlaid PtM fuel cell catalyst
By pretreating the carbon support at high temperature under the protection of inert gas, forming a PtM alloy under the strictly controlled ratio of Pt to M atoms, nano SiO2 was prepared as a structural additive in combination with the sol-gel method to form a mosaic structure, which solved the problems of high cost of Pt/C catalysts, low utilization of active sites and reduced stability in the prior art, and achieved a mosaic PtM catalyst with high activity, high stability and low cost.
Patent Information
- Application Number
- CN202510313493.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-17
- Publication Date
- 2025-06-03
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The existing Pt/C catalysts have high cost, low utilization of active sites, and the stability of transition metal dissolution in an acidic environment makes it difficult to achieve a mosaic PtM catalyst with high activity, high stability and low cost.
Pretreat the carbon support at high temperature under the protection of inert gas to form a pretreated carbon support; then, under the strictly controlled ratio of Pt to M atoms, a PtM alloy is formed, and nano SiO2 is prepared as a structural additive by the sol-gel method to form a mosaic structure to avoid agglomeration of PtM alloy particles and improve the durability of the catalyst.
A mosaic PtM catalyst with high activity and high stability is achieved, which reduces the amount of precious metal Pt, extends the service life of the catalyst, and effectively inhibits the dissolution of transition metals.
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Abstract
Description
Technical Field
[0001] This application relates to the technical field of fuel cell catalyst preparation, and more specifically, it relates to a preparation method of an embedded PtM fuel cell catalyst. Background Art
[0002] As an efficient and clean energy conversion device, the performance of a fuel cell highly depends on the activity and stability of the catalyst. Currently, platinum (Pt)-based catalysts are the main catalysts for the oxygen reduction reaction (ORR) at the cathode of fuel cells. However, the high cost and scarcity of Pt limit its large-scale application. Traditional Pt / C catalysts have high costs, low utilization of active sites, and are prone to Pt dissolution / agglomeration. Although PtM alloy catalysts (such as PtCo, PtNi) improve activity, the dissolution of transition metals (M) in an acidic environment leads to a decrease in stability. Therefore, it is urgent to develop a preparation method for an embedded PtM catalyst with high activity, high stability, and low cost. Balancing high activity and high durability and achieving stable anchoring of transition metals (M) and suppressing the dissolution of transition metals are of great significance. Summary of the Invention
[0003] To solve the technical problems mentioned in the background art, this application provides a preparation method of an embedded PtM fuel cell catalyst.
[0004] A preparation method of an embedded PtM fuel cell catalyst includes the following preparation steps; Step 1: Under the protection of an inert gas, heat the carbon support to 500 - 600 °C and keep it warm for 2 - 3 h to obtain a pretreated carbon support; Step 2: Dissolve the Pt precursor and the M precursor in an ethanol / water solution to obtain a mixed precursor solution; Disperse the pretreated carbon support in deionized water and ultrasonically disperse it for 0.5 - 1 h to obtain a support suspension; Slowly drop the mixed precursor solution into the support suspension, adjust the pH to 8 - 10, stir for 2 - 3 h, add a NaBH 4 solution, stir at room temperature for 2 - 4 h, centrifuge, wash, and dry to obtain a support loaded with PtM alloy nanoparticles; Step 3: Mix tetraethyl orthosilicate, ethanol, water, and ammonia water, and while stirring, heat it to 40 - 45 °C and stir and react for 2 - 4 h, then centrifuge and separate, wash, and dry to obtain nano-SiO 2 particles; Step 4: The support loaded with PtM alloy nanoparticles and nano-SiO 2The particles are mixed, ethanol is added, and ultrasonic dispersion is carried out for 1 - 2 h. Ascorbic acid is added, and the reaction is carried out at 60 - 80 °C for 3 - 5 h. After the reaction is completed, centrifugation is carried out. The precipitate after centrifugation is soaked in a NaOH solution, stirred for 12 - 15 h, centrifuged, washed, and after heat treatment, an embedded PtM fuel cell catalyst is obtained.
[0005] Preferably, in step 1, the heating rate of the carbon support is 5 - 8 °C.
[0006] Preferably, in step 1, the carbon support is Vulcan XC - 72.
[0007] Preferably, in step 2, the Pt precursor is H 2 PtCl 6 and / or K 2 PtCl 4 .
[0008] Preferably, in step 2, the M precursor is Co(NO 3 ) 2 , NiCl 2 one of them.
[0009] Preferably, in step 2, the Pt precursor and the M precursor are mixed according to the atomic ratio of Pt and M of 1 - 3:2 - 4.
[0010] Preferably, in step 2, the solid - liquid ratio of the mixed precursor solution is 1 - 2:10 - 30.
[0011] Preferably, in step 2, the solid - liquid ratio of the carrier suspension is 1 - 3:40 - 80.
[0012] Preferably, in step 2, the volume ratio of the mixed precursor solution, the carrier suspension, and the NaBH 4 solution is 1 - 2:15 - 25:10 - 30.
[0013] Preferably, in step 2, the concentration of the NaBH 4 solution is 0.1 - 0.5 moL / L Preferably, in step 3, the volume ratio of tetraethyl orthosilicate, ethanol, water, and ammonia water is 1 - 2:10 - 15:5 - 7:1 - 1.2.
[0014] Preferably, in step 3, the mass fraction of ammonia water is 25 - 28%.
[0015] Preferably, in step 4, the mass ratio of the carrier loaded with PtM alloy nanoparticles, nano - SiO 2 particles, ethanol, and ascorbic acid is 2 - 5:1 - 3:20 - 30:0.2 - 0.5.
[0016] Preferably, in step 4, the concentration of the NaOH solution is 0.1 - 0.3 moL / L.
[0017] Preferably, the heat treatment conditions in step 4 are as follows: under an Ar / H 2 mixed gas, heating up to 400 - 600 °C at a heating rate of 3 - 8 °C / min, and holding for 2 - 5 h.
[0018] Preferably, in the Ar / H 2 mixed gas, the volume fraction of H 2 is 5 - 15%.
[0019] In summary, the present application has the following beneficial effects: Under the protection of an inert gas, through high-temperature pretreatment at a specific temperature and heating rate, the present application removes impurities on the surface of the carbon support, increases active sites, and improves the dispersion and loading stability of metal nanoparticles. By strictly controlling the atomic ratio of Pt to M to form the PtM alloy, the amount of precious metal Pt is significantly reduced, and at the same time, the oxygen reduction reaction (ORR) activity and anti-poisoning ability are enhanced by using alloy effects (such as electronic structure adjustment and synergistic catalysis). The nano-SiO prepared by the sol-gel method 2 as a structural aid forms an inlaid structure in the subsequent steps, which can not only prevent the agglomeration of PtM alloy particles and maintain a high specific surface area, but also the inert surface of SiO 2 can reduce the direct contact between the metal and the electrolyte, extend the catalyst life, and heat treatment under an Ar / H 2 mixed gas can not only stabilize the alloy structure, inhibit sintering, but also improve the durability of the catalyst. Specific Embodiments
[0020] The following further elaborates on the present application with reference to examples.
[0021] The carbon support (Vulcan XC-72, product number: HH9160CGS2J0) used in the examples and comparative examples of the present application was purchased from Shenzhen Longdi Chemical Co., Ltd.; tetraethyl orthosilicate (content 28%) was purchased from Shandong Shengrui Chemical Technology Co., Ltd.
[0022] Examples 1 - 3 provide a preparation method for an inlaid PtM fuel cell catalyst.
[0023] Example 1 A preparation method for an inlaid PtM fuel cell catalyst, comprising the following preparation steps: Step 1: Under nitrogen protection, heat the carbon support to 500 °C at a heating rate of 5 °C, and hold for 2 h to obtain a pretreated carbon support, where the carbon support is Vulcan XC-72; Step 2. Dissolve H 2 PtCl 6 and Co(NO 3 ) 2 in an ethanol solution with a mass fraction of 60% according to an atomic ratio of Pt to Co of 1:2 to obtain a mixed precursor solution with a solid-liquid ratio of 1:10. Disperse the pretreated carbon support in deionized water, and perform ultrasonic dispersion for 0.5 h with an ultrasonic power of 100 W and an ultrasonic frequency of 40 KHz to obtain a support suspension with a solid-liquid ratio of 1:40. Slowly drop the mixed precursor solution into the support suspension, adjust the pH to 8, stir for 2 h at a stirring speed of 300 rpm, add a NaBH 4 solution, stir at room temperature for 2 h at a stirring speed of 400 rpm, centrifuge at a centrifugal speed of 5000 rpm for 10 min, wash with deionized water 3 times, and dry at 60°C for 12 h to obtain a support loaded with PtM alloy nanoparticles. Among them, the volume ratio of the mixed precursor solution, the support suspension, and the NaBH 4 solution is 1:15:10, and the concentration of the NaBH 4 solution is 0.1 moL / L; Step 3. Mix tetraethyl orthosilicate, ethanol, water, and ammonia water according to a volume ratio of 1:10:5:1. Under stirring, raise the temperature to 40°C, stir at a stirring speed of 300 rpm, and stir and react for 2 h. Centrifuge at a centrifugal speed of 5000 rpm for 10 min, wash, and dry at 60°C for 10 h to obtain nano-SiO 2 particles. Among them, the mass fraction of ammonia water is 25% for mixing; Step 4. Mix the support loaded with PtM alloy nanoparticles and nano-SiO 2 particles, add ethanol, perform ultrasonic dispersion for 1 h with an ultrasonic power of 100 W and an ultrasonic frequency of 40 KHz, add ascorbic acid, stir at 60°C at a stirring speed of 400 rpm, and react for 3 h. After the reaction, centrifuge at a centrifugal speed of 5000 rpm for 10 min, soak the centrifuged precipitate in a 0.1 moL / L NaOH solution, stir for 12 h at a stirring speed of 400 rpm, centrifuge at a centrifugal speed of 5000 rpm for 10 min, wash, and under an Ar / H 2 mixed gas, with the H 2 volume fraction being 5%, raise the temperature to 400°C at a heating rate of 3°C / min, and keep the temperature for 2 h to obtain an embedded PtM fuel cell catalyst. Among them, the mass ratio of the support loaded with PtM alloy nanoparticles, nano-SiO 2 particles, ethanol, and ascorbic acid is 2:1:20:0.2.
[0024] Example 2 A preparation method of an embedded PtM fuel cell catalyst, comprising the following preparation steps: Step 1: Under nitrogen protection, heat the carbon support at a heating rate of 6 °C to 550 °C and keep it at this temperature for 2.5 h to obtain a pretreated carbon support, where the carbon support is Vulcan XC-72; Step 2: Dissolve H 2 PtCl 6 and Co(NO 3 ) 2 in a 70% ethanol solution by mass according to the atomic ratio of Pt to Co of 2:3 to obtain a mixed precursor solution with a solid-liquid ratio of 1.5:20; Disperse the pretreated carbon support in deionized water, ultrasonically disperse it for 0.8 h, with an ultrasonic power of 110 W and an ultrasonic frequency of 50 KHz, to obtain a carrier suspension with a solid-liquid ratio of 2:60; Slowly drop the mixed precursor solution into the carrier suspension, adjust the pH to 9, stir for 2.5 h at a stirring speed of 450 rpm, add NaBH 4 solution, stir at room temperature for 3 h at a stirring speed of 500 rpm, centrifuge at a centrifugal speed of 6000 rpm for 20 min, wash with deionized water 3 times, and dry at 70 °C for 16 h to obtain a carrier loaded with PtM alloy nanoparticles, where the volume ratio of the mixed precursor solution, the carrier suspension, and the NaBH 4 solution is 1.5:20:20, and the concentration of the NaBH 4 solution is 0.3 moL / L; Step 3: Mix tetraethyl orthosilicate, ethanol, water, and ammonia water in a volume ratio of 1.5:13:6:1.1, heat to 42 °C under stirring at a stirring speed of 400 rpm, stir and react for 3 h, centrifuge at a centrifugal speed of 6000 rpm for 15 min, wash, and dry at 80 °C for 11 h to obtain nano-SiO 2 particles, where the mass fraction of ammonia water is 27%; Step 4: Mix the carrier loaded with PtM alloy nanoparticles and nano-SiO 2 particles, add ethanol, ultrasonically disperse for 1.5 h with an ultrasonic power of 110 W and an ultrasonic frequency of 50 KHz, add ascorbic acid, stir at 70 °C at a stirring speed of 500 rpm for 4 h. After the reaction, centrifuge at a centrifugal speed of 8000 rpm for 15 min, soak the centrifuged precipitate in a 0.2 moL / L NaOH solution, stir for 14 h at a stirring speed of 500 rpm, centrifuge at a centrifugal speed of 8000 rpm for 15 min, wash, and under an Ar / H 2 mixed gas, with the volume fraction of H 2 being 10%, heat at a heating rate of 5 °C / min to 500 °C and keep it at this temperature for 4 h to obtain an embedded PtM fuel cell catalyst, where the carrier loaded with PtM alloy nanoparticles, nano-SiO2 The mass ratio of the particles, ethanol, ascorbic acid is 4:2:25:0.4.
[0025] Example 3 A preparation method of an inlaid PtM fuel cell catalyst, comprising the following preparation steps: Step 1: Under nitrogen protection, heat the carbon support at a heating rate of 8 °C to 600 °C and keep it at this temperature for 3 h to obtain a pretreated carbon support, where the carbon support is Vulcan XC-72; Step 2: Dissolve H 2 PtCl 6 and Co(NO 3 ) 2 in an ethanol solution with a mass fraction of 80% according to the atomic ratio of Pt to Co of 3:4 to obtain a mixed precursor solution with a solid-liquid ratio of 2:30; disperse the pretreated carbon support in deionized water, ultrasonically disperse for 1 h, with an ultrasonic power of 120 W and an ultrasonic frequency of 60 KHz to obtain a carrier suspension with a solid-liquid ratio of 3:80; slowly drop the mixed precursor solution into the carrier suspension, adjust the pH to 10, stir for 3 h at a stirring speed of 600 rpm, add NaBH 4 solution, stir at room temperature for 4 h at a stirring speed of 600 rpm, centrifuge at a centrifugal speed of 8000 rpm for 30 min, wash with deionized water 3 times, and dry at 80 °C for 20 h to obtain a carrier loaded with PtM alloy nanoparticles, where the volume ratio of the mixed precursor solution, the carrier suspension and the NaBH 4 solution is 2:25:30, and the concentration of the NaBH 4 solution is 0.5 moL / L; Step 3: Mix tetraethyl orthosilicate, ethanol, water and ammonia water according to a volume ratio of 2:15:7:1.2, heat to 45 °C under stirring at a stirring speed of 500 rpm, stir and react for 4 h, centrifuge at a centrifugal speed of 8000 rpm for 20 min, wash, and dry at 100 °C for 12 h to obtain nano-SiO 2 particles, where the mass fraction of ammonia water is 28%; Step 4: Mix the carrier loaded with PtM alloy nanoparticles and nano-SiO 2 particles, add ethanol, ultrasonically disperse for 2 h with an ultrasonic power of 120 W and an ultrasonic frequency of 60 KHz, add ascorbic acid, stir at 80 °C at a stirring speed of 600 rpm for 5 h. After the reaction, centrifuge at a centrifugal speed of 10000 rpm for 20 min, soak the centrifuged precipitate in a 0.3 moL / L NaOH solution, stir for 15 h at a stirring speed of 600 rpm, centrifuge at a centrifugal speed of 10000 rpm for 20 min, wash, and dry in Ar / H 2Under a mixed gas, H 2 with a volume fraction of 15%, is heated at a heating rate of 8 °C / min to 600 °C and held for 5 h to obtain an embedded PtM fuel cell catalyst. Among them, the mass ratio of the carrier loaded with PtM alloy nanoparticles, nano-SiO 2 particles, ethanol, and ascorbic acid is 5:3:30:0.5.
[0026] Comparative Example 1 A preparation method of an embedded PtM fuel cell catalyst includes the following preparation steps: Step 1: Under nitrogen protection, the carbon carrier is heated at a heating rate of 3 °C to 400 °C and held for 2 h to obtain a pretreated carbon carrier. Among them, the carbon carrier is Vulcan XC-72; Step 2: H 2 PtCl 6 and Co(NO 3 ) 2 are dissolved in an ethanol solution with a mass fraction of 60% according to the atomic ratio of Pt to Co of 1:2 to obtain a mixed precursor solution with a solid-liquid ratio of 1:10; the pretreated carbon carrier is dispersed in deionized water, ultrasonically dispersed for 0.5 h, the ultrasonic power is 100 W, and the ultrasonic frequency is 40 KHz to obtain a carrier suspension with a solid-liquid ratio of 1:40; the mixed precursor solution is slowly added dropwise to the carrier suspension, the pH is adjusted to 8, stirred for 2 h, the stirring speed is 300 rpm, NaBH 4 solution is added, stirred at room temperature for 2 h, the stirring speed is 400 rpm, centrifuged at a centrifugal speed of 5000 rpm for 10 min, washed with deionized water 3 times, and dried at 60 °C for 12 h to obtain a carrier loaded with PtM alloy nanoparticles. Among them, the volume ratio of the mixed precursor solution, the carrier suspension, and the NaBH 4 solution is 1:15:10, and the concentration of the NaBH 4 solution is 0.1 moL / L; Step 3: Tetraethyl orthosilicate, ethanol, water, and ammonia water are mixed according to a volume ratio of 1:10:5:1, heated to 40 °C under stirring, the stirring speed is 300 rpm, stirred and reacted for 2 h, centrifuged at a centrifugal speed of 5000 rpm for 10 min, washed, and dried at 60 °C for 10 h to obtain nano-SiO 2 particles. Among them, the mass fraction of ammonia water is 25% mixed; Step 4: The carrier loaded with PtM alloy nanoparticles and nano-SiO 2The particles were mixed, ethanol was added, and ultrasonic dispersion was carried out for 1 h at an ultrasonic power of 100 W and an ultrasonic frequency of 40 KHz. Ascorbic acid was added, and the mixture was stirred at 400 rpm at 60 °C for 3 h. After the reaction was completed, centrifugation was carried out at a centrifugal speed of 5000 rpm for 10 min. The centrifuged precipitate was immersed in a 0.1 moL / L NaOH solution and stirred for 12 h at a stirring speed of 400 rpm. Then, centrifugation was carried out at a centrifugal speed of 5000 rpm for 10 min, followed by washing. Under an Ar / H 2 mixed gas, the H 2 volume fraction was 5%, and the temperature was raised to 400 °C at a heating rate of 3 °C / min and held for 2 h to obtain an embedded PtM fuel cell catalyst. Among them, the mass ratio of the carrier loaded with PtM alloy nanoparticles, nano-SiO 2 particles, ethanol, and ascorbic acid was 2:1:20:0.2.
[0027] Comparative Example 2 A method for preparing an embedded PtM fuel cell catalyst includes the following preparation steps: Step 1: Under nitrogen protection, the carbon carrier was heated to 500 °C at a heating rate of 5 °C and held for 2 h to obtain a pretreated carbon carrier, where the carbon carrier was Vulcan XC-72; Step 2: H 2 PtCl 6 and Co(NO 3 ) 2 were dissolved in an ethanol solution with a mass fraction of 60% according to the atomic ratio of Pt to Co of 1:1 to obtain a mixed precursor solution with a solid-liquid ratio of 1:10. The pretreated carbon carrier was dispersed in deionized water and ultrasonically dispersed for 0.5 h at an ultrasonic power of 100 W and an ultrasonic frequency of 40 KHz to obtain a carrier suspension with a solid-liquid ratio of 1:40. The mixed precursor solution was slowly added dropwise to the carrier suspension, the pH was adjusted to 8, and the mixture was stirred for 2 h at a stirring speed of 300 rpm. Then, NaBH 4 solution was added, and the mixture was stirred at room temperature for 2 h at a stirring speed of 400 rpm. Centrifugation was carried out at a centrifugal speed of 5000 rpm for 10 min, washed 3 times with deionized water, and dried at 60 °C for 12 h to obtain a carrier loaded with PtM alloy nanoparticles. Among them, the volume ratio of the mixed precursor solution, the carrier suspension, and the NaBH 4 solution was 1:15:10, and the concentration of the NaBH 4 solution was 0.1 moL / L; Step 3: Mix tetraethyl orthosilicate, ethanol, water, and ammonia water in a volume ratio of 1:10:5:1. Under stirring, heat up to 40°C, with a stirring speed of 300 rpm, stir and react for 2 h, centrifuge at a centrifugal speed of 5000 rpm for 10 min, wash, and dry at 60°C for 10 h to obtain nano-SiO 2 particles, where the mass fraction of ammonia water is 25% for mixing; Step 4: Mix the carrier loaded with PtM alloy nanoparticles and nano-SiO 2 particles, add ethanol, ultrasonically disperse for 1 h, with an ultrasonic power of 100 W and an ultrasonic frequency of 40 KHz, add ascorbic acid, at 60°C, with a stirring speed of 400 rpm, react for 3 h. After the reaction, centrifuge at a centrifugal speed of 5000 rpm for 10 min, soak the centrifuged precipitate in 0.1 moL / L NaOH solution, stir for 12 h, with a stirring speed of 400 rpm, centrifuge at a centrifugal speed of 5000 rpm for 10 min, wash, and under an Ar / H 2 mixed gas, with the H 2 volume fraction of 5%, heat up to 400°C at a heating rate of 3°C / min, and keep warm for 2 h to obtain the embedded PtM fuel cell catalyst, where the mass ratio of the carrier loaded with PtM alloy nanoparticles, nano-SiO 2 particles, ethanol, and ascorbic acid is 2:1:20:0.2.
[0028] Comparative Example 3 A preparation method of an embedded PtM fuel cell catalyst, comprising the following preparation steps: Step 1: Under nitrogen protection, heat the carbon carrier at a heating rate of 5°C to 500°C and keep warm for 2 h to obtain a pretreated carbon carrier, where the carbon carrier is Vulcan XC-72; Step 2: Dissolve H 2 PtCl 6 and Co(NO 3 ) 2 in an ethanol solution with a mass fraction of 60% according to the atomic ratio of Pt to Co of 1:5 to obtain a mixed precursor solution with a solid-liquid ratio of 1:10; Disperse the pretreated carbon carrier in deionized water, ultrasonically disperse for 0.5 h, with an ultrasonic power of 100 W and an ultrasonic frequency of 40 KHz, to obtain a carrier suspension with a solid-liquid ratio of 1:40; Slowly drop the mixed precursor solution into the carrier suspension, adjust the pH to 8, stir for 2 h, with a stirring speed of 300 rpm, add NaBH 4The solution was stirred at room temperature for 2 h at a stirring speed of 400 rpm, centrifuged at a centrifugal speed of 5000 rpm for 10 min, washed 3 times with deionized water, and dried at 60 °C for 12 h to obtain a support loaded with PtM alloy nanoparticles. Among them, the volume ratio of the mixed precursor solution, the support suspension, and NaBH 4 solution was 1:15:10, and the concentration of NaBH 4 solution was 0.1 moL / L; Step 3: Mix tetraethyl orthosilicate, ethanol, water, and ammonia water in a volume ratio of 1:10:5:1. Under stirring, heat it to 40 °C, with a stirring speed of 300 rpm, stir and react for 2 h, centrifuge at a centrifugal speed of 5000 rpm for 10 min, wash, and dry at 60 °C for 10 h to obtain nano-SiO 2 particles, where the mass fraction of ammonia water is 25% for mixing; Step 4: Mix the support loaded with PtM alloy nanoparticles and nano-SiO 2 particles, add ethanol, ultrasonically disperse for 1 h, with an ultrasonic power of 100 W and an ultrasonic frequency of 40 KHz, add ascorbic acid, at 60 °C, with a stirring speed of 400 rpm, react for 3 h. After the reaction, centrifuge at a centrifugal speed of 5000 rpm for 10 min, soak the centrifuged precipitate in 0.1 moL / L NaOH solution, stir for 12 h at a stirring speed of 400 rpm, centrifuge at a centrifugal speed of 5000 rpm for 10 min, wash, and under an Ar / H 2 mixed gas, with the H 2 volume fraction being 5%, heat it to 400 °C at a heating rate of 3 °C / min, and keep it at a constant temperature for 2 h to obtain an embedded PtM fuel cell catalyst. Among them, the mass ratio of the support loaded with PtM alloy nanoparticles, nano-SiO 2 particles, ethanol, and ascorbic acid is 2:1:20:0.2.
[0029] Comparative Example 4 A preparation method of an embedded PtM fuel cell catalyst, comprising the following preparation steps: Step 1: Under nitrogen protection, heat the carbon support at a heating rate of 5 °C to 500 °C and keep it at a constant temperature for 2 h to obtain a pretreated carbon support, where the carbon support is Vulcan XC-72; Step 2: H 2 PtCl 6 and Co(NO 3 ) 2Dissolve according to the atomic ratio of Pt and Co being 1:2 in an ethanol solution with a mass fraction of 60% to obtain a mixed precursor solution with a solid-liquid ratio of 1:10; disperse the pretreated carbon carrier in deionized water, ultrasonically disperse for 0.5 h, with an ultrasonic power of 100 W and an ultrasonic frequency of 40 KHz to obtain a carrier suspension with a solid-liquid ratio of 1:40; slowly drop the mixed precursor solution into the carrier suspension, adjust the pH to 8, stir for 2 h, with a stirring speed of 300 rpm, and add NaBH 4 solution, stir at room temperature for 2 h, with a stirring speed of 400 rpm, centrifuge at a centrifugal speed of 5000 rpm for 10 min, wash with deionized water 3 times, and dry at 60 °C for 12 h to obtain a carrier loaded with PtM alloy nanoparticles. Among them, the volume ratio of the mixed precursor solution, the carrier suspension, and the NaBH 4 solution is 1:15:10, and the concentration of the NaBH 4 solution is 0.1 moL / L; Step 3: Mix tetraethyl orthosilicate, ethanol, water, and ammonia water in a volume ratio of 1:10:5:1, heat to 40 °C under stirring, with a stirring speed of 300 rpm, stir and react for 2 h, centrifuge at a centrifugal speed of 5000 rpm for 10 min, wash, and dry at 60 °C for 10 h to obtain nano-SiO 2 particles, where the mass fraction of ammonia water is 25% in the mixture; Step 4: Mix the carrier loaded with PtM alloy nanoparticles and the nano-SiO 2 particles, add ethanol, ultrasonically disperse for 1 h, with an ultrasonic power of 100 W and an ultrasonic frequency of 40 KHz, add ascorbic acid, stir at 60 °C, with a stirring speed of 400 rpm, react for 3 h. After the reaction, centrifuge at a centrifugal speed of 5000 rpm for 10 min, soak the centrifuged precipitate in a 0.1 moL / L NaOH solution, stir for 12 h, with a stirring speed of 400 rpm, centrifuge at a centrifugal speed of 5000 rpm for 10 min, wash, and under an Ar / H 2 mixed gas, with the H 2 volume fraction being 5%, heat at a heating rate of 3 °C / min to 300 °C, and keep warm for 2 h to obtain an embedded PtM fuel cell catalyst. Among them, the mass ratio of the carrier loaded with PtM alloy nanoparticles, the nano-SiO 2 particles, ethanol, and ascorbic acid is 2:1:20:0.2.
[0030] Comparative Example 5 A preparation method of an embedded PtM fuel cell catalyst, including the following preparation steps: Step 1: Under nitrogen protection, heat the carbon support at a heating rate of 5 °C to 500 °C and hold for 2 h to obtain a pretreated carbon support, where the carbon support is Vulcan XC-72; Step 2: Dissolve H 2 PtCl 6 and Co(NO 3 ) 2 in a 60% ethanol solution by mass according to the atomic ratio of Pt to Co of 1:2 to obtain a mixed precursor solution with a solid-liquid ratio of 1:10; Disperse the pretreated carbon support in deionized water, ultrasonically disperse for 0.5 h, with an ultrasonic power of 100 W and an ultrasonic frequency of 40 KHz, to obtain a carrier suspension with a solid-liquid ratio of 1:40; Slowly drop the mixed precursor solution into the carrier suspension, adjust the pH to 8, stir for 2 h at a stirring speed of 300 rpm, add NaBH 4 solution, stir at room temperature for 2 h at a stirring speed of 400 rpm, centrifuge at a centrifugal speed of 5000 rpm for 10 min, wash 3 times with deionized water, and dry at 60 °C for 12 h to obtain a carrier loaded with PtM alloy nanoparticles, where the volume ratio of the mixed precursor solution, the carrier suspension, and the NaBH 4 solution is 1:15:10, and the concentration of the NaBH 4 solution is 0.1 moL / L; Step 3: Mix tetraethyl orthosilicate, ethanol, water, and ammonia in a volume ratio of 1:10:5:1, heat to 40 °C under stirring at a stirring speed of 300 rpm, stir and react for 2 h, centrifuge at a centrifugal speed of 5000 rpm for 10 min, wash, and dry at 60 °C for 10 h to obtain nano-SiO 2 particles, where the mass fraction of ammonia is 25%; Step 4: Mix the carrier loaded with PtM alloy nanoparticles and nano-SiO 2 particles, add ethanol, ultrasonically disperse for 1 h with an ultrasonic power of 100 W and an ultrasonic frequency of 40 KHz, add ascorbic acid, stir at 60 °C at a stirring speed of 400 rpm for 3 h, after the reaction, centrifuge at a centrifugal speed of 5000 rpm for 10 min, soak the centrifuged precipitate in a 0.1 moL / L NaOH solution, stir for 12 h at a stirring speed of 400 rpm, centrifuge at a centrifugal speed of 5000 rpm for 10 min, wash, and under an Ar / H 2 mixed gas, with the volume fraction of H 2 being 5%, heat at a heating rate of 3 °C / min to 700 °C and hold for 2 h to obtain an embedded PtM fuel cell catalyst, where the carrier loaded with PtM alloy nanoparticles, nano-SiO 2The mass ratio of the particles, ethanol, ascorbic acid is 2:1:20:0.2.
[0031] Comparative Example 6 A preparation method of an embedded PtM fuel cell catalyst, comprising the following preparation steps: Step 1: Under nitrogen protection, heat the carbon support at a heating rate of 5 °C to 500 °C and keep it warm for 2 h to obtain a pretreated carbon support, where the carbon support is Vulcan XC-72; Step 2: Dissolve H 2 PtCl 6 and Co(NO 3 ) 2 in an ethanol solution with a mass fraction of 60% according to the atomic ratio of Pt to Co of 1:2 to obtain a mixed precursor solution with a solid-liquid ratio of 1:10; Disperse the pretreated carbon support in deionized water, ultrasonically disperse for 0.5 h, with an ultrasonic power of 100 W and an ultrasonic frequency of 40 KHz to obtain a carrier suspension with a solid-liquid ratio of 1:40; Slowly drop the mixed precursor solution into the carrier suspension, adjust the pH to 8, stir for 2 h, with a stirring speed of 300 rpm, add NaBH 4 solution, stir at room temperature for 2 h, with a stirring speed of 400 rpm, centrifuge at a centrifugal speed of 5000 rpm for 10 min, wash with deionized water 3 times, and dry at 60 °C for 12 h to obtain a carrier loaded with PtM alloy nanoparticles, where the volume ratio of the mixed precursor solution, the carrier suspension and the NaBH 4 solution is 1:15:10, and the concentration of the NaBH 4 solution is 0.1 moL / L; Step 3: Mix tetraethyl orthosilicate, ethanol, water and ammonia water in a volume ratio of 1:10:5:1, heat to 40 °C under stirring, with a stirring speed of 300 rpm, stir and react for 2 h, centrifuge at a centrifugal speed of 5000 rpm for 10 min, wash, and dry at 60 °C for 10 h to obtain nano-SiO 2 particles, where the mass fraction of ammonia water is 25% mixed; Step 4: The carrier loaded with PtM alloy nanoparticles and nano-SiO 2The particles were mixed, ethanol was added, and ultrasonic dispersion was carried out for 1 h with an ultrasonic power of 100 W and an ultrasonic frequency of 40 KHz. Ascorbic acid was added, and the mixture was stirred at 400 rpm at 60 °C for 3 h. After the reaction, centrifugation was carried out at a centrifugal speed of 5000 rpm for 10 min. The centrifuged precipitate was immersed in 0.1 moL / L NaOH solution and stirred at 400 rpm for 12 h. Then, centrifugation was carried out at a centrifugal speed of 5000 rpm for 10 min, followed by washing. Under pure helium, the temperature was raised to 400 °C at a heating rate of 3 °C / min and held for 2 h to obtain the embedded PtM fuel cell catalyst. Among them, the carrier loaded with PtM alloy nanoparticles, nano-SiO 2 The mass ratio of the particles, ethanol, ascorbic acid is 2:1:20:0.2.
[0032] Performance test The performance parameters of the embedded PtM fuel cell catalysts prepared in Examples 1-3 and Comparative Examples 1-6 of this application are specifically as follows: ORR activity: Using a rotating disk electrode (RDE) in 0.1 M HClO 4 solution, cyclic voltammetry was used with a scanning range of 0.05 - 1.2 V vs. RHE and a scanning rate of 50 mV / s. The test was carried out under an inert gas atmosphere; Durability test: 30K triangular wave potential cycles (scanning rate 100 mV / s) were carried out in the range of 0.6 - 1.0 V vs. RHE. After the test, the ORR activity was re-measured. The percentage of the ORR activity after 30k cycles to the initial ORR activity was the activity retention rate; Transition metal (Co) dissolution rate: The catalyst was immersed in 0.5 M H 2 SO 4 and shaken at 60 °C for 24 h. The concentration of Co in the solution was detected by inductively coupled plasma mass spectrometry (ICP-MS); 2+ concentration; The test results are shown in Table 1.
[0033] Table 1 Performance parameters of the embedded PtM fuel cell catalysts prepared in Examples 1-3 and Comparative Examples 1-6
[0034] As can be seen from Table 1, the embedded PtM fuel cell catalyst prepared in this application not only has high activity and high stability, but also has high durability, realizes the stable anchoring of transition metal (M), effectively reduces the dissolution of transition metal, and effectively extends the service life of the fuel cell.
[0035] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.
Claims
1. A method for preparing a mosaic PtM fuel cell catalyst, characterized in that: The method comprises the following preparation steps: Step 1, under the protection of inert gas, the carbon carrier is heated to 500-600° C. and kept warm for 2-3 hours to obtain a pretreated carbon carrier; Step 2, dissolving the Pt precursor and the M precursor in an ethanol / water solution to obtain a mixed precursor solution; The pretreated carbon carrier is dispersed in deionized water and ultrasonically dispersed for 0.5-1h to obtain a carrier suspension; The mixed precursor solution is slowly added dropwise to the carrier suspension, the pH is adjusted to 8-10, stirred for 2-3 hours, NaBH4 solution is added, stirred at room temperature for 2-4 hours, centrifuged, washed, and dried to obtain a carrier loaded with PtM alloy nanoparticles; Step 3, mix ethyl orthosilicate, ethanol, water and ammonia water, raise the temperature to 40-45°C while stirring, stir and react for 2-4 hours, centrifuge, wash and dry to obtain nano-SiO2 particles; Step 4: Mix the carrier loaded with PtM alloy nanoparticles and nano-SiO2 particles, add ethanol, ultrasonically disperse for 1-2 hours, add ascorbic acid, react at 60-80°C for 3-5 hours, centrifuge after the reaction, soak the precipitate after centrifugation in NaOH solution, stir for 12-15 hours, centrifuge, wash, and heat treat to obtain a mosaic PtM fuel cell catalyst.
2. The method for preparing a mosaic PtM fuel cell catalyst according to claim 1, characterized in that: The heating rate of the carbon carrier in step 1 is 5-8° C.; the carbon carrier is Vulcan XC-72.
3. The method for preparing a mosaic PtM fuel cell catalyst according to claim 1, characterized in that: In step 2, the Pt precursor is H2PtCl6 and / or K2PtCl4; the M precursor is one of Co(NO3)2 and NiCl2; the Pt precursor and the M precursor are mixed according to the atomic ratio of Pt to M of 1-3:2-4.
4. The method for preparing a mosaic PtM fuel cell catalyst according to claim 1, characterized in that: The solid-liquid ratio of the mixed precursor solution in step 2 is 1-2:10-30; the solid-liquid ratio of the carrier suspension is 1-3:40-80.
5. The method for preparing a mosaic PtM fuel cell catalyst according to claim 1, characterized in that: In the step 2, the volume ratio of the mixed precursor solution, the carrier suspension and the NaBH4 solution is 1-2:15-25:10-30; the concentration of the NaBH4 solution is 0.1-0.5 mol / L.
6. The method for preparing a mosaic PtM fuel cell catalyst according to claim 1, characterized in that: In step 3, the volume ratio of tetraethyl orthosilicate, ethanol, water and ammonia water is 1-2:10-15:5-7:1-1.2; the mass fraction of ammonia water is 25-28%.
7. The method for preparing a mosaic PtM fuel cell catalyst according to claim 1, characterized in that: In step 4, the mass ratio of the carrier loaded with PtM alloy nanoparticles, nano-SiO2 particles, ethanol, and ascorbic acid is 2-5: 1-3: 20-30: 0.2-0.
5.
8. The method for preparing a mosaic PtM fuel cell catalyst according to claim 1, characterized in that: The concentration of the NaOH solution in step 4 is 0.1-0.3 mol / L.
9. The method for preparing a mosaic PtM fuel cell catalyst according to claim 1, characterized in that: The heat treatment conditions in step 4 are: in an Ar / H2 mixed gas, heating to 400-600°C at a heating rate of 3-8°C / min, and keeping the temperature for 2-5h.
10. The method for preparing a mosaic PtM fuel cell catalyst according to claim 9, characterized in that: In the Ar / H2 mixed gas, the volume fraction of H2 is 5-15%.