Carbon-supported platinum-based nanoparticles and preparation method thereof
Highly dispersed carbon-supported platinum-based nanoparticles were prepared using a "two-way dynamic confinement" method, which solved the problems of low activity and high cost of fuel cell cathode catalysts and enabled efficient and simple large-scale production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-29
- Publication Date
- 2026-03-27
AI Technical Summary
Existing cathode catalysts for fuel cells have low activity and poor stability, and precious metal materials are expensive. Traditional preparation methods are complex and difficult to achieve small-particle-size, highly dispersed platinum-based alloy catalysts.
By employing a "two-way dynamic confinement" method, the difference in solubility product between alkaline earth metal salts and platinum and transition metal salts is used to form carbonate or sulfide precipitates during the drying process of the mixed solution. Combined with high-temperature heat treatment, in-situ reduction and alloying of platinum-transition metal hydroxides are achieved, forming highly dispersed carbon-supported platinum-based nanoparticles.
The prepared carbon-supported platinum-based nanoparticles exhibit excellent electrochemical activity, with a specific activity 4-6 times that of traditional commercial platinum-carbon nanoparticles. The particle size is less than 3.5-4 nm, which reduces the cost of fuel cell materials, simplifies the preparation process, and facilitates large-scale production.
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Figure CN121748423A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of proton exchange membrane fuel cell cathode catalysts, specifically relating to a carbon-supported platinum-based nanoparticle and its preparation method. Background Technology
[0002] Currently, cathode catalysts used in fuel cells suffer from problems such as low activity, poor stability, and high cost of precious metal materials. There is an urgent need for methods to mass-produce highly stable and highly active catalysts, and it is necessary to significantly reduce material costs by introducing inexpensive transition metals to form alloys with platinum.
[0003] Currently, among the methods for preparing platinum-based alloy catalysts: the traditional sacrificial template method requires the preparation of a template before loading the metal, which involves complex procedures, poor confinement effect, and difficulty in removing the template afterward; while the co-precipitation method is relatively simple to operate, the synthesized nanoparticles are prone to agglomeration, resulting in a wide particle size distribution and poor uniformity. Furthermore, to improve the crystallinity and alloying degree of the catalyst, high-temperature heat treatment is usually required, which further exacerbates particle aggregation and growth, hindering the formation of highly dispersed catalytic active centers with high specific surface area.
[0004] In summary, existing synthetic methods have significant limitations in precisely controlling the interaction between metal precursors and templates, making it difficult to achieve in-situ, dynamically controlled growth of ultrafine nanoparticles. Therefore, there is an urgent need to develop a new method that is simple to implement and can control the interaction between the metal and the support or template in real time during synthesis, enabling the preparation of small-particle-size, highly active platinum-based alloy catalysts. Summary of the Invention
[0005] One of the objectives of this invention is to provide a method for preparing carbon-supported platinum-based nanoparticles, in order to solve the problems of complex preparation processes and large particle size and low activity of existing platinum-based alloy catalysts.
[0006] The second objective of this invention is to provide carbon-supported platinum-based nanoparticles prepared by the above-described method.
[0007] The objective of this invention can be achieved through the following technical solutions: A carbon-supported platinum-based nanoparticle comprises the following raw materials in parts by weight: 0.4-2 parts carbon powder, 0.1-2 parts complexing agent, 1 part platinum salt, 0.3-3 parts soluble transition metal salt, 0.1-0.5 parts soluble alkaline earth metal salt, and 0.2-0.6 parts precipitant.
[0008] Furthermore, the carbon powder is conductive carbon black, specifically at least one of conductive carbon black EC-300J, conductive carbon black EC-600J, and conductive carbon black XC-72R.
[0009] Furthermore, the complexing agent is an amino acid compound, specifically at least one of glycine, glutamic acid, cysteine, and phenylalanine.
[0010] Further, the platinum salt is at least one selected from chloroplatinic acid, potassium chloroplatinate, potassium chloroplatinate, platinum acetylacetonate, platinum nitrate, and dichlorodiammineplatinum.
[0011] Furthermore, the soluble transition metal salt is at least one selected from nickel chloride, nickel nitrate, cobalt nitrate, cobalt chloride, ferric chloride, and ferric acetylacetone. Furthermore, the soluble alkaline earth metal salt is at least one of beryllium chloride, magnesium chloride, calcium chloride, strontium chloride, and barium chloride.
[0012] Furthermore, the precipitant is soluble in carbonates and / or sulfides.
[0013] Furthermore, the soluble carbonate is at least one of sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.
[0014] Furthermore, the sulfide is sodium sulfide and / or potassium sulfide.
[0015] A method for preparing carbon-supported platinum-based nanoparticles includes the following steps: Step 1: At a temperature of 0-5℃, disperse the carbon powder in deionized water to obtain a carbon carrier aqueous solution. Add a complexing agent, platinum salt, soluble transition metal salt, soluble alkaline earth metal salt, and precipitant to the carbon carrier aqueous solution, stir evenly, and adjust the pH value to 7-9 to obtain a mixed solution. After the raw materials are added according to the required proportion, due to the different solubility products (Ksp), for alkaline earth metal salts, the concentration required for carbonate / sulfide precipitates to reach supersaturation is lower than that for hydroxide precipitates, thus making it easier to form carbonate / sulfide precipitates. Similarly, transition metals and platinum also form hydroxide precipitates due to their different solubility products. Therefore, during the drying process, the formation of insoluble carbonate and / or sulfide precipitates of the above alkaline earth metal salts is controlled, thereby forming a composite structure on the carbon support in situ, which uses alkaline earth metal precipitates as templates and platinum-transition metal hydroxides as precursors, with complexing agents. Step 2: After drying the mixed solution, grind it and sieve it to obtain a solid powder; Step 3: Place the solid powder in a tube furnace and heat treat it under a reducing atmosphere to obtain the heat-treated product; In a reducing atmosphere, the nanoscale confinement constructed by alkaline earth metal template particles promotes the synchronous reduction of platinum and transition metal precursors, and forces them to diffuse and nucleate only within the confinement space, thereby directionally transforming the "composite precursor structure" constructed in step 1 into carbon-supported platinum-based alloy nanoparticles with uniform particle size and high dispersion. Step 4: The heat-treated product is subjected to ice bath acid washing, and after acid washing, it is taken out and dried to obtain carbon-supported platinum-based nanoparticles.
[0016] This invention proposes a "two-way dynamic confinement" method to achieve the controllable preparation of ultrafine, highly dispersed carbon-supported platinum-based nanoparticles; First, the solubility product (K0) between alkaline earth metal salts and platinum and transition metal salts is utilized. sp The difference is that during the drying process of the mixed solution, alkaline earth metal ions preferentially form carbonate or sulfide precipitates; the large specific surface area and abundant surface sites of the carbon carrier effectively confine the nucleation and growth of these precipitate particles, so that they are uniformly dispersed on the carbon surface in an amorphous and extremely fine form, forming the first-level confinement (carbon carrier → template particles). Subsequently, during the high-temperature heat treatment stage, these uniformly distributed, extremely fine alkaline earth metal precipitates, as nanoscale spatial barriers, constitute a second-level physical confinement (template particles → alloy particles) for the thermal migration, reduction, and alloying processes of the platinum-transition metal hydroxide precursor, effectively inhibiting the agglomeration of nanoparticles and abnormal grain growth at high temperatures. In this process, the confinement role changes dynamically and continuously from carbon support to template particles, and then to the final alloy particles. The entire method seamlessly integrates template preparation, confinement effect application, and target product synthesis into a continuous and efficient process, overcoming the problems of cumbersome steps, poor confinement effect, and easy particle agglomeration in traditional methods.
[0017] Furthermore, the preparation of the carbon carrier aqueous solution in step 1 is carried out using a microfluidic homogenizer for dispersion.
[0018] Furthermore, the mass fraction of the carbon support aqueous solution in step 1 is 0.5-1%.
[0019] Furthermore, the carbon support aqueous solution described in step 1, when tested with a laser particle size analyzer, has a particle size that satisfies D50 of 0.3-0.7 μm and D90 of 1.0-5.0 μm.
[0020] Furthermore, the pH adjuster in step 1 is potassium hydroxide and / or sodium hydroxide.
[0021] Furthermore, a 200-mesh sieve is used for sieving in step 2.
[0022] Furthermore, the drying temperature in step 2 is 70-120℃.
[0023] Furthermore, in step 3, the reducing atmosphere is one of a hydrogen-argon mixture, high-purity argon, high-purity nitrogen, and high-purity carbon monoxide. The volume ratio of argon to hydrogen in the hydrogen-argon mixture is 95:5, and the purity of the high-purity argon, high-purity nitrogen, and high-purity carbon monoxide is ≥99.99%.
[0024] Furthermore, in step 3, the heat treatment temperature is 200-500℃, and the heat treatment time is 1-3h.
[0025] Furthermore, in step 4, the acid concentration used in the pickling process is 0.001-0.1 mol / L, and the acid is at least one of sulfuric acid solution, hydrochloric acid solution, nitric acid solution and acetic acid solution.
[0026] Furthermore, in step 4, the pickling time is 10-60 minutes, and the drying temperature is 70-90℃.
[0027] The beneficial effects of this invention are: 1. This invention proposes a "two-way dynamic confinement" method, which solves the problems of complex operation steps, poor confinement effect and difficulty in removing the template in the traditional template method on the one hand, and improves the current situation that the nanoparticles synthesized by the traditional co-precipitation method are prone to agglomeration and have uneven particle size on the other hand, providing a new idea for the preparation of platinum-based alloys.
[0028] 2. The carbon-supported platinum-based nanoparticles prepared by this invention have excellent electrochemical activity as a cathode catalyst for fuel cells. Their specific activity is 4-6 times that of traditional commercial platinum-carbon, and the synthesis method is simple, easy to operate, highly reproducible, and easy to achieve large-scale production.
[0029] 3. The synthesis steps of this invention are simple and the method is highly universal. For catalysts with similar structures but different functions, only the type of precursor salt needs to be adjusted without changing the synthesis process, and it can be easily extended to different types of catalysts.
[0030] 4. The catalyst prepared by this invention has an extremely small particle size, measured by XRD to be only 2-3 nm, which is lower than the 3.5-4 nm of traditional commercial platinum-carbon. The platinum-based particles have a large specific surface area, which greatly improves the utilization rate of platinum metal and reduces the cost of fuel cell materials. Attached Figure Description
[0031] The invention will now be further described with reference to the accompanying drawings.
[0032] Figure 1 The image shows a comparison of the XRD patterns of carbon-supported platinum-based nanoparticles in Example 1 of the present invention and the commercial PtC catalyst with 40% loading in Comparative Example 1. Figure 2 The electrochemical CV and LSV curves of carbon-supported platinum-based nanoparticles in Example 1 of this invention were measured under a standard three-electrode system. Figure 3 The electrochemical CV and LSV curves of the 40% loaded commercial PtC catalyst of Comparative Example 1 of this invention were measured in a standard three-electrode system. Figure 4The image shows a comparison of the XRD patterns of carbon-supported platinum-based nanoparticles in Example 2 of the present invention and the commercial PtC catalyst with 60% loading in Comparative Example 2. Figure 5 The electrochemical CV and LSV curves of carbon-supported platinum-based nanoparticles in Example 2 of this invention were measured under a standard three-electrode system. Figure 6 The electrochemical CV and LSV curves for Comparative Example 2, a 60% loaded commercial PtC catalyst, were measured under a standard three-electrode system. Detailed Implementation
[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0035] Obviously, the following description is merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios without any inventive effort. Furthermore, it is understood that although the effort involved in such development may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.
[0036] However, there may be instances where unnecessary detailed descriptions are omitted. For example, detailed descriptions of well-known matters or repetitive descriptions of essentially the same structure may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art. Furthermore, the following description is provided to enable those skilled in the art to fully understand this application and is not intended to limit the subject matter of the claims.
[0037] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions, and all technical features and optional technical features of this application can be combined to form new technical solutions.
[0038] The following is a detailed description of the embodiments of this application.
[0039] In a first aspect, embodiments of this application provide carbon-supported platinum-based nanoparticles, comprising the following raw materials in parts by weight: 0.4-2 parts carbon powder, 0.1-2 parts complexing agent, 1 part platinum salt, 0.3-3 parts soluble transition metal salt, 0.1-0.5 parts soluble alkaline earth metal salt, and 0.2-0.6 parts precipitant.
[0040] In some embodiments, the carbon powder is conductive carbon black, specifically at least one of conductive carbon black EC-300J, conductive carbon black EC-600J, and conductive carbon black XC-72R.
[0041] In some embodiments, the complexing agent is an amino acid compound, specifically at least one of glycine, glutamic acid, cysteine, and phenylalanine.
[0042] In some embodiments, the platinum salt is at least one selected from chloroplatinic acid, potassium chloroplatinate, potassium chloroplatinate, platinum acetylacetonate, platinum nitrate, and dichlorodiammineplatinum.
[0043] In some embodiments, the soluble transition metal salt is at least one selected from nickel chloride, nickel nitrate, cobalt nitrate, cobalt chloride, ferric chloride, and ferric acetylacetone. In some embodiments, the soluble alkaline earth metal salt is at least one of beryllium chloride, magnesium chloride, calcium chloride, strontium chloride, and barium chloride.
[0044] In some embodiments, the precipitant is soluble in carbonates and / or sulfides.
[0045] Furthermore, the soluble carbonate is at least one of sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.
[0046] Furthermore, the sulfide is sodium sulfide and / or potassium sulfide.
[0047] Secondly, embodiments of this application provide a method for preparing carbon-supported platinum-based nanoparticles, comprising the following steps: Step 1: At a temperature of 0-5℃, disperse the carbon powder in deionized water to obtain a carbon carrier aqueous solution. Add a complexing agent, platinum salt, soluble transition metal salt, soluble alkaline earth metal salt, and precipitant to the carbon carrier aqueous solution, stir evenly, and adjust the pH value to 7-9 to obtain a mixed solution. Step 2: After drying the mixed solution, grind it and sieve it to obtain a solid powder; Step 3: Place the solid powder in a tube furnace and heat treat it under a reducing atmosphere to obtain the heat-treated product; Step 4: The heat-treated product is subjected to ice bath acid washing, and after acid washing, it is taken out and dried to obtain carbon-supported platinum-based nanoparticles.
[0048] In some embodiments, the preparation of the carbon support aqueous solution in step 1 is performed using a microfluidic homogenizer for dispersion.
[0049] In some embodiments, the mass fraction of the carbon support aqueous solution in step 1 is 0.5-1%.
[0050] In some embodiments, the carbon support aqueous solution described in step 1 has a particle size that meets the requirements of D50 of 0.3-0.7 μm and D90 of 1.0-5.0 μm when tested by a laser particle size analyzer.
[0051] In some embodiments, the pH adjuster in step 1 is potassium hydroxide and / or sodium hydroxide.
[0052] In some implementations, a 200-mesh sieve is used for sieving in step 2.
[0053] In some implementations, the drying temperature in step 2 is 70-120°C.
[0054] In some embodiments, the reducing atmosphere in step 3 is one of a hydrogen-argon mixture, high-purity argon, high-purity nitrogen, and high-purity carbon monoxide. The volume ratio of argon to hydrogen in the hydrogen-argon mixture is 95:5, and the purity of the high-purity argon, high-purity nitrogen, and high-purity carbon monoxide is ≥99.99%.
[0055] In some implementations, the heat treatment temperature in step 3 is 200-500°C, and the heat treatment time is 1-3 hours.
[0056] In some embodiments, the acid concentration used in the pickling process in step 4 is 0.001-0.1 mol / L, and the acid is at least one of sulfuric acid solution, hydrochloric acid solution, nitric acid solution and acetic acid solution.
[0057] In some implementations, the pickling time in step 4 is 10-60 minutes, and the drying temperature is 70-90°C.
[0058] The following is a detailed description with reference to specific examples.
[0059] Example 1 A method for preparing carbon-supported platinum-based nanoparticles includes the following steps: Step 1: At 3℃, 0.8g of conductive carbon black EC-300J was dispersed in 80mL of deionized water using a microfluidic homogenizer to obtain a carbon carrier aqueous solution. The particle size of the carbon carrier aqueous solution, as measured by a laser particle size analyzer, met the requirements of D50 being 0.3-0.7μm and D90 being 1.0-5.0μm. While maintaining 3℃ and stirring at 1000rpm, 0.2g of glycine, 1g of platinum nitrate, 0.5g of cobalt chloride, 0.3g of calcium chloride, and 0.3g of sodium carbonate were added to the carbon carrier aqueous solution. After stirring evenly, potassium hydroxide was added to adjust the pH to 8 to obtain a mixed solution. Step 2: Dry the mixed solution at 120℃, grind it through a 200-mesh sieve to obtain a solid powder; Step 3: Place the solid powder in a tube furnace and treat it at 300°C for 2 hours in a mixed atmosphere of 5% hydrogen and 95% argon to obtain the heat-treated product; Step 4: The heat-treated product was acid-washed in an ice bath with a 0.01 mol / L nitric acid solution for 60 min. After washing with deionized water, it was dried at 70 °C to obtain carbon-supported platinum-based nanoparticles.
[0060] Comparative Example 1 This comparative example uses a 40% loading of commercial PtC catalyst, model Hispec4000, purchased from Johnson Matthey.
[0061] Phase analysis was performed on the product obtained in Example 1 and the substances in Comparative Example 1, and the results are as follows: Figure 1 As shown, the substances from Example 1 and Comparative Example 1 were prepared as ink (10 mg catalyst, 120 μL 5% Nafion solution, 4600 μL water, 280 μL isopropanol) and electrochemical tests were performed in a three-electrode system. The test results are as follows. Figure 2 and Figure 3 As shown, where Figure 2 a and Figure 2 b represents the electrochemical CV and LSV curves of the carbon-supported platinum-based nanoparticles in Example 1 measured under a standard three-electrode system. Figure 3 c and Figure 3 Figures d and d show the electrochemical CV and LSV curves of the 40% loaded commercial PtC catalyst in Comparative Example 1, measured under standard three-electrode conditions. Figures 1-3 The 40PtCo / C used in Example 1 was the product obtained, while the commercial 40PtC used in Comparative Example 1 was the material. Using the Scherrer formula, the particle sizes of the materials in Example 1 and Comparative Example 1 were calculated to be 2.2 nm and 3.4 nm, respectively, demonstrating that the method in Example 1 can prepare extremely fine metal nanoparticles. Figure 2 and Figure 3According to the data calculation, the MA (mass activity) of the carbon-supported platinum-based nanoparticles in Example 1 is 0.48 A / mgPt, while the MA (mass activity) of the 40% loaded commercial PtC catalyst in Comparative Example 1 is 0.14 A / mgPt. This indicates that the activity of the product obtained in Example 1 is much higher than that of commercial platinum-carbon.
[0062] Example 2 A method for preparing carbon-supported platinum-based nanoparticles includes the following steps: Step 1: At 3℃, 0.4g of conductive carbon black EC-600J was dispersed in 80mL of deionized water using a microfluidic homogenizer to obtain a carbon carrier aqueous solution. The particle size of the carbon carrier aqueous solution, as measured by a laser particle size analyzer, met the requirements of D50 being 0.3-0.7μm and D90 being 1.0-5.0μm. While maintaining 3℃ and stirring at 1200rpm, 0.5g of cysteine, 1g of potassium chloroplatinate, 1.2g of nickel nitrate, 0.3g of barium chloride, and 0.3g of sodium carbonate were added to the carbon carrier aqueous solution. After stirring evenly, potassium hydroxide was added to adjust the pH to 8 to obtain a mixed solution. Step 2: Dry the mixed solution at 90℃, grind it through a 200-mesh sieve to obtain a solid powder; Step 3: Place the solid powder in a tube furnace and treat it at 500°C for 3 hours under a mixed atmosphere of 99.99% pure argon to obtain the heat-treated product; Step 4: The heat-treated product was acid-washed in an ice bath with a 0.05 mol / L nitric acid solution for 30 min. After washing with deionized water, it was dried at 90 °C to obtain carbon-supported platinum-based nanoparticles.
[0063] Comparative Example 2 This comparative example uses a 60% loaded commercial PtC catalyst, model Hispec 9100, purchased from Johnson Matthey.
[0064] Phase analysis was performed on the product obtained in Example 2 and the substances in Comparative Example 2, and the results are as follows: Figure 4 As shown, the solution was prepared as ink (10 mg catalyst, 120 μL 5% Nafion solution, 4600 μL water, 280 μL isopropanol) and electrochemical tests were performed in a three-electrode system. The test results are as follows. Figure 5 and Figure 6 As shown, where Figure 5 e and Figure 5 f represents the electrochemical CV and LSV curves of the carbon-supported platinum-based nanoparticles in Example 2 measured under a standard three-electrode system. Figure 6 g and Figure 6 h represents the electrochemical CV and LSV curves of the comparative example 2, a commercial PtC catalyst with 60% loading, measured under standard three-electrode conditions. Figures 4-6The 60PtCo / C in Example 2 is the product obtained. Commercial 60PtC is not used in Comparative Example 2. Using the Scherrer formula, the particle sizes of the substances in Example 1 and Comparative Example 1 were calculated to be 3.2 nm and 4.2 nm, respectively, demonstrating that the method in Example 2 can prepare extremely fine metal nanoparticles. Figure 2 According to the data calculation, the MA (mass-to-activity ratio) of the carbon-supported platinum-based nanoparticles in Example 2 is 0.28 A / mgPt, while the MA (mass-to-activity ratio) of the 60% loaded commercial PtC catalyst in Comparative Example 1 is 0.12 A / mgPt. This indicates that the activity of the product obtained in Example 2 is much higher than that of commercial platinum-carbon.
[0065] Example 3 A method for preparing carbon-supported platinum-based nanoparticles, which differs from Example 1 only in step 1, is as follows: At a temperature of 1℃, 0.4g of conductive carbon black EC-300J was dispersed in 40mL of deionized water using a microfluidic homogenizer to obtain a carbon carrier aqueous solution. The particle size of the carbon carrier aqueous solution, as measured by a laser particle size analyzer, met the requirements of D50 of 0.3-0.7μm and D90 of 1.0-5.0μm. While maintaining the temperature at 0℃ and stirring at 800rpm, 0.2g of glycine, 1g of platinum nitrate, 0.3g of cobalt chloride, 0.1g of calcium chloride, and 0.6g of sodium carbonate were added to the carbon carrier aqueous solution. After stirring evenly, potassium hydroxide was added to adjust the pH to 8, resulting in a mixed solution.
[0066] Example 4 A method for preparing carbon-supported platinum-based nanoparticles, which differs from Example 1 only in step 1, is as follows: At 5℃, 2g of conductive carbon black EC-300J was dispersed in 100mL of deionized water using a microfluidic homogenizer to obtain a carbon carrier aqueous solution. The particle size of the carbon carrier aqueous solution, as measured by a laser particle size analyzer, met the requirements of D50 being 0.3-0.7μm and D90 being 1.0-5.0μm. While maintaining 5℃ and stirring at 1200rpm, 2g of glycine, 1g of platinum nitrate, 3g of cobalt chloride, 0.5g of calcium chloride, and 0.6g of sodium carbonate were added to the carbon carrier aqueous solution. After stirring evenly, potassium hydroxide was added to adjust the pH to 8, resulting in a mixed solution.
[0067] Example 5 A method for preparing carbon-supported platinum-based nanoparticles, which differs from Example 1 only in that calcium chloride in Example 1 is replaced with an equal mass of magnesium chloride.
[0068] Example 6 A method for preparing carbon-supported platinum-based nanoparticles, which differs from Example 1 only in that calcium chloride in Example 1 is replaced with an equal mass of strontium chloride.
[0069] Example 7 A method for preparing carbon-supported platinum-based nanoparticles, which differs from Example 1 only in that glycine in Example 1 is replaced with an equal mass of glutamic acid.
[0070] Example 8 A method for preparing carbon-supported platinum-based nanoparticles, which differs from Example 1 only in that glycine in Example 1 is replaced with an equal mass of phenylalanine.
[0071] Comparative Example 3 A method for preparing carbon-supported platinum-based nanoparticles, which differs from Example 1 only in that calcium chloride is removed in Example 1.
[0072] Comparative Example 4 A method for preparing carbon-supported platinum-based nanoparticles, which differs from Example 1 only in that sodium carbonate is removed in Example 1.
[0073] Comparative Example 5 A method for preparing carbon-supported platinum-based nanoparticles, which differs from Example 1 only in that glycine is removed from Example 1.
[0074] Comparative Example 6 A method for preparing carbon-supported platinum-based nanoparticles, which differs from Example 1 only in that calcium chloride and glycine are removed in Example 1.
[0075] Following the methods described in Examples 1 and 2, particle size analysis and specific activity calculations were performed on the products obtained in Examples 3-8 and Comparative Examples 1-6. The statistical results are shown in Table 1. Table 1
[0076] As can be seen from the data recorded in Table 1, compared with Comparative Examples 1-6, the platinum-based nanoparticles prepared in Examples 1-8 have smaller particle sizes and higher specific activity. Specifically, for Examples 1, 3, 4, 5, and 6, after removing the complexing agent, alkaline earth metal salt precipitation, and / or complexing agent, the particle size of the prepared platinum-based nanoparticles increased significantly, and the specific activity decreased sharply. This proves that alkaline earth metal salt precipitation and complexing agent play an important role in particle size control in this method and can significantly improve catalyst activity and platinum metal utilization.
[0077] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
Claims
1. A carbon supported platinum-based nanoparticle, characterized in that, The following raw materials are included by weight parts: carbon powder 0.4-2 parts, complexing agent 0.1-2 parts, platinum salt 1 part, soluble transition metal salt 0.3-3 parts, soluble alkaline earth metal salt 0.1-0.5 parts, and precipitant 0.2-0.6 parts.
2. The carbon supported platinum-based nanoparticles of claim 1, wherein, The carbon powder is conductive carbon black.
3. The carbon supported platinum-based nanoparticles of claim 1, wherein, The soluble alkaline earth metal salt is at least one of beryllium chloride, magnesium chloride, calcium chloride, strontium chloride, and barium chloride.
4. The carbon supported platinum-based nanoparticles of claim 1, wherein, The precipitant is soluble carbonate and / or sulfide, the soluble carbonate being at least one of sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate, and the sulfide being sodium sulfide and / or potassium sulfide.
5. A method of preparing carbon-supported platinum-based nanoparticles, characterized in that, A method for preparing the carbon-supported platinum-based nanoparticles as claimed in any one of claims 1-4, comprising the following steps: Step 1: at a temperature of 0-5℃, disperse the carbon powder in deionized water to obtain a carbon carrier aqueous solution, add the complexing agent, platinum salt, soluble transition metal salt, soluble alkaline earth metal salt, and precipitant to the carbon carrier aqueous solution, stir to uniformity, adjust the pH value to 7-9, and obtain a mixed solution; Step 2: after drying the mixed solution, grind and sieve to obtain a solid powder; Step 3: place the solid powder in a tube furnace and perform heat treatment under a reducing atmosphere to obtain a heat-treated product; Step 4: perform ice-bath acid washing on the heat-treated product, dry after acid washing, and obtain the carbon-supported platinum-based nanoparticles.
6. The method of claim 5, wherein the platinum-based nanoparticles are prepared on carbon support. The mass fraction of the carbon carrier aqueous solution in Step 1 is 0.5-1%.
7. The method for preparing carbon-supported platinum-based nanoparticles according to claim 5, characterized in that, The carbon carrier aqueous solution in Step 1 has a particle size of D50 0.3-0.7 μm and D90 1.0-5.0 μm when tested on a laser particle size analyzer.
8. The method of claim 5, wherein the platinum-based nanoparticles are prepared on carbon support. The heat treatment temperature in Step 3 is 200-500℃, and the heat treatment time is 1-3h.
9. The method of claim 5, wherein the platinum-based nanoparticles are prepared on carbon support. The acid solution concentration used in the acid washing process in Step 4 is 0.001-0.1 mol / L, and the acid solution is at least one of sulfuric acid solution, hydrochloric acid solution, nitric acid solution, and acetic acid solution.
10. The method of claim 5, wherein the platinum-based nanoparticles are prepared on carbon support. The acid washing time in Step 4 is 10-60 min, and the drying temperature is 70-90℃.