A boron-doped carbon carrier, a boron-doped platinum-carbon catalyst, and a preparation method and application thereof

Abstract

The present application relates to a kind of boron-doped carbon carrier, boron-doped platinum carbon catalyst and the preparation method and application of both.The preparation method of the boron-doped platinum carbon catalyst includes: porous carbon material is mixed with phenylboronic acid according to mass ratio 1:(1.5~6) grinding, is calcined under 600~900 ℃ inert atmosphere to obtain boron-doped carbon carrier;Boron-doped carbon carrier is mixed with platinum precursor solution, after adding alcohol solution, with lye adjust pH to 7~8, in 80 ℃ oil bath heating reduction 4 hours, after washing dry to obtain final product.The present application strengthens the interaction of platinum and carbon carrier by boron doping, the average particle size of the platinum carbon catalyst platinum nanoparticle obtained is 2~3 nm, is uniformly dispersed, has the advantages such as high hydrogen evolution activity and stability, especially suitable for proton exchange membrane electrolytic water cathode hydrogen evolution reaction.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of catalysts, and in particular, relates to a boron-doped carbon carrier, a boron-doped platinum-carbon catalyst, and a preparation method and application thereof. BACKGROUND

[0002] With the acceleration of global population growth and industrialization, energy demand continues to rise. Traditional fossil energy such as coal, oil and natural gas is non-renewable, and the consumption process is accompanied by a large amount of CO2 emission. In order to achieve the goal of carbon neutralization, the development of clean energy has become an urgent need. Water electrolysis hydrogen production technology is considered as the core component of future clean energy system due to its advantages of wide raw material sources, high hydrogen purity and environmental protection. At present, proton exchange membrane water electrolysis (PEMWE) technology has become the most promising hydrogen production route due to its high current density, fast response ability and excellent system integration. However, its large-scale application is still restricted by the performance bottleneck and cost problem of cathode hydrogen evolution reaction catalyst.

[0003] Commercial platinum-carbon catalysts, as a representative class of electrocatalysts, play a crucial role in contemporary energy conversion and storage due to their near-ideal hydrogen adsorption free energy. However, under actual water electrolysis conditions, platinum-carbon catalysts still face severe stability and cost challenges. First, in a strong acidic environment, platinum nanoparticles are prone to migration and aggregation, resulting in a decrease in active sites. Second, the carbon carrier will undergo electrochemical oxidation corrosion at high potentials, thereby destroying the structural stability of the catalyst and further accelerating the performance decay of the catalyst. In addition, the high price of platinum metal further restricts the economic feasibility of PEMWE technology.

[0004] To improve the performance of platinum-carbon catalysts and reduce costs, researchers have explored various modification strategies. In carbon-based catalysts, doping different non-metallic or metallic elements can effectively adjust the electronic structure and surface chemical properties of the carbon carrier, thereby optimizing its interaction with metal nanoparticles. This modification method not only enhances the stability of the catalyst, but also improves its intrinsic activity through electronic effects. Boron exhibits special modification potential due to its unique electronic properties and atomic size advantages. Boron atoms have a small atomic radius and high electronegativity, and the introduction of boron atoms can significantly change the electronic structure of carbon materials, enhancing their electronic interaction with platinum nanoparticles, thereby effectively inhibiting the migration and aggregation of platinum. In addition, boron doping can also improve the oxidation resistance of the carbon carrier.

[0005] Therefore, it is of great significance to develop an efficient, low-cost and environmentally friendly preparation method for boron-doped platinum-carbon catalysts to promote the development of water electrolysis hydrogen production technology. SUMMARY

[0006] The purpose of the embodiments of the present application is to solve the problems of the prior art, and provide a boron-doped carbon carrier, a boron-doped platinum-carbon catalyst, and a preparation method and application thereof. By using phenylboronic acid as an organic boron source, and through a simple grinding-pyrolysis process, uniform doping of boron atoms in various carbon carriers can be achieved. Then, platinum nanoparticles are loaded on the boron-doped carbon carrier, and a boron-doped platinum-carbon catalyst is obtained. By boron doping, the interaction between platinum and the carbon carrier is enhanced, the dispersion and stability of platinum particles are significantly improved, and high electrochemical activity is maintained.

[0007] To achieve the above-mentioned purposes, the embodiments of the present application first provide a preparation method of a boron-doped carbon carrier, which comprises the following steps: mixing and grinding a porous carbon material and phenylboronic acid at a mass ratio of 1:(1.5-6) to obtain a mixture with a particle size D50≤100 μm, and then calcining the mixture under the protection of an inert gas at 600-900℃ for 2-4 hours to obtain the boron-doped carbon carrier.

[0008] Further preferably, the porous carbon material is selected from one of Ketjen black ECP600JD, Ketjen black EC600JD, Ketjen black EC300J, and Cabot BP2000. Preferably, the porous carbon material is Ketjen black ECP600JD.

[0009] Further preferably, the heating rate of the calcination is 3-8℃ / min.

[0010] Further preferably, the grinding is mechanical grinding, and a ball mill or an agate mortar is used in the mechanical grinding.

[0011] When manual grinding is performed using the agate mortar, the grinding time is not less than 40 min.

[0012] When the grinding is performed using the ball mill, the volume ratio of the ball to the material is 1:3, the rotation speed is 400 rpm, and the grinding time is not less than 30 min.

[0013] Another purpose of the present application is to provide a boron-doped carbon carrier prepared by the above method. In the boron-doped carbon carrier, boron elements are mainly doped in the carbon skeleton in the form of chemical bonding, and the atomic percentage content of the boron elements is 6-11at%. The specific surface area of the boron-doped carbon carrier is 900-1500 m 2 / g.

[0014] A further object of the present application is to provide a method for preparing a high-performance platinum-carbon catalyst using the above-mentioned boron-doped carbon carrier, which is not dependent on a specific type of carbon carrier or platinum precursor and has wide process compatibility. The method comprises the following steps: preparing a boron-doped carbon carrier by the method described above; and loading platinum nanoparticles on the boron-doped carbon carrier, wherein the method for loading the platinum nanoparticles is a liquid-phase reduction method, which comprises: mixing and dispersing the boron-doped carbon carrier with a platinum precursor solution, adding an alcohol solution, adjusting the pH to 7-10 with a lye, heating to reduce the metal precursor, and performing filtration, washing, and drying treatment on the product after heating reaction to obtain the boron-doped platinum-carbon catalyst.

[0015] Further preferably, the heating and reduction of the metal precursor refers to heating and reduction at 70-90℃ for 3-5 hours.

[0016] Further preferably, the heating and reduction of the metal precursor refers to oil bath heating, and the oil bath heating temperature is 80℃, and the heating time is 4 h.

[0017] Further preferably, the platinum precursor is at least one of chloroplatinic acid, platinum tetrachloride, and potassium chloroplatinate, and is preferably chloroplatinic acid.

[0018] Further preferably, the alcohol solution is at least one of ethylene glycol, ethanol, and glycerol, and the volume ratio of alcohol to water is 1:1.

[0019] Further preferably, the platinum loading amount can be controlled by adjusting the amount of platinum precursor, and the platinum loading amount is 10%-40%, and a typical value is 20%.

[0020] Further preferably, the lye is a sodium hydroxide solution or a potassium hydroxide solution.

[0021] Further preferably, the mixing and dispersing of the boron-doped carbon carrier and the platinum precursor solution is performed by stirring and ultrasonic dispersion, wherein the stirring time is 10 min, and the ultrasonic time is 30 min.

[0022] Further preferably, the washing solution in the above-mentioned step is an aqueous solution, and the washing number is 6-8 times.

[0023] Further preferably, the drying temperature in the above-mentioned step is 50-80℃, and the drying time is 10-14 h.

[0024] A further object of the present application is to provide a boron-doped platinum-carbon catalyst prepared by the above-mentioned method, which comprises a boron-doped carbon carrier and platinum nanoparticles loaded thereon.

[0025] Further preferably, the boron-doped platinum-carbon catalyst has a specific surface area of 10 mA·cm -2The hydrogen evolution overpotential under a current density is less than or equal to 85.2 mV, and the electrochemical mass activity is greater than or equal to 0.135 A mg -1 Pt; the platinum loading in the boron-doped platinum carbon catalyst is 20 wt%, and the average particle size of the platinum particles is 2-3 nm.

[0026] In addition, the application also provides an application of the catalyst in a hydrogen evolution reaction of a proton exchange membrane electrolysis water cathode.

[0027] Compared with the prior art, the application has the following remarkable advantages:

[0028] 1. The application uses phenylboronic acid as a green boron source, and realizes uniform carbon support boron doping through high-temperature chemical bonding, thereby significantly enhancing the interface interaction between the carbon support and the active component.

[0029] 2. The application uses a liquid-phase reduction method, and ethylene glycol is used as a solvent and a reducing agent at the same time, so that the preparation process is green and safe, the operation process is simple, large-scale continuous production is adapted, and the cost is effectively reduced, thereby providing new inspiration for the hydrogen production industry by electrolysis of water.

[0030] 3. The nanoparticle size of the platinum carbon catalyst prepared by the application is 2-3 nm, and the boron doping improves the catalytic activity of the catalyst, thereby realizing higher efficiency and better stability in the process of electrolysis of water. BRIEF DESCRIPTION OF DRAWINGS

[0031] The above features and advantages of the application will become more apparent and easily understood from the following description of exemplary embodiments thereof in conjunction with the accompanying drawings.

[0032] Figure 1 A schematic diagram of a boron-doped platinum carbon catalyst preparation method;

[0033] Figure 2 A Fourier transform infrared spectroscopy (FTIR) diagram of a boron-doped carbon support prepared in Example 1 of the application;

[0034] Figure 3 An X-ray diffraction (XRD) spectrum of a boron-doped carbon support prepared in Example 1 of the application;

[0035] Figure 4 A nitrogen adsorption / desorption curve and a pore size distribution diagram of a boron-doped carbon support prepared in Example 1 of the application;

[0036] Figure 5 XRD diagrams of platinum carbon catalysts with different boron doping ratios prepared in Examples 1-3 of the application. DETAILED DESCRIPTION

[0037] The following will be described by specific embodiments of the present application, familiar with the skilled person can easily understand the advantages and effects of the present application from the disclosure, obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative efforts fall within the scope of the present application.

[0038] Example 1:

[0039] (1) 0.5 g of Ketjenblack ECP600JD carbon powder and 0.75 g of phenylboronic acid were weighed and mixed, and then ground in a maroon mortar for 40 min. After grinding, the mixture was tested by a laser particle size analyzer, and the particle size distribution D50 was measured to be 52 μm. The obtained uniform mixture was transferred to a porcelain boat and placed in a tube furnace under an inert gas protection atmosphere, heated to 600℃ at a heating rate of 5℃ / min, and kept at constant temperature for 3 h. After cooling to room temperature, the boron-doped carbon carrier was obtained, denoted as 1.5B@ECP600.

[0040] (2) 0.5 g of the boron-doped carbon powder in step (1) was weighed in a 500 mL three-necked round-bottom flask, 80 mL of deionized water was added, and after stirring for 10 min, it was placed in an ultrasonic cleaner for 30 min to uniformly disperse the carbon powder in water.

[0041] (3) 334 mg of chloroplatinic acid was weighed in a beaker, 20 mL of deionized water was added, and after ultrasonic treatment for 3 min to make the solution uniform, it was poured into the carbon powder solution in step (2), and stirred for 4 h to make the mixture uniform.

[0042] (4) 100 mL of ethylene glycol was added to the mixed solution in step (3), and after stirring for 15 min, 160 μL of 5 mol / L NaOH solution was added.

[0043] (5) The reaction system in step (4) was placed in an oil bath, heated at 80℃ for 4 h, and then cooled to room temperature and washed with deionized water for 6 times.

[0044] (6) The product was placed in a drying box and dried at 60℃ for 14 h, then taken out, ground into powder with a mortar, and collected for use.

[0045] Example 2:

[0046] (1) Take 0.5 g of carbon powder Ketjenblack ECP600JD and 1.5 g of phenylboronic acid, mix and grind using a ball mill, with a ball-to-material volume ratio of 1:3, at a rotation speed of 400 rpm, for 0.5 hours. After grinding, the mixture is tested using a laser particle size analyzer, and the particle size distribution D50 is measured to be 49 μm. The obtained uniform mixture is transferred to a porcelain boat, and placed in a tube furnace under an inert gas atmosphere, heated to 600°C at a heating rate of 5°C / min, and kept at constant temperature for 3 hours. After cooling to room temperature, the boron-doped carbon carrier is obtained, and is recorded as 3B@ECP600.

[0047] In this step, the particle size of the mixture after mixing and grinding of the carbon powder and phenylboronic acid needs to meet certain requirements: first, smaller particle size leads to more uniform mixing, which increases the uniformity of boron doping of the subsequently generated carrier; second, it improves the specific surface area of the subsequently generated carrier. The grinding step is not limited to the technical means adopted in Examples 1 and 2, and various existing physical crushing techniques can also be used. According to practice, the particle size of the mixture after mixing and grinding of the carbon powder and phenylboronic acid should meet D50≤100 μm, and on this basis, those skilled in the art can choose the grinding means and the fineness of grinding according to their own conditions and needs.

[0048] (2) Take 0.5 g of the boron-doped carbon powder in step (1) into a 500 mL three-necked round-bottom flask, add 80 mL of deionized water, stir for 10 min, and then place it in an ultrasonic cleaner for 30 min to uniformly disperse the carbon powder in water.

[0049] (3) Take 334 mg of chloroplatinic acid into a beaker, add 20 mL of deionized water, and ultrasonic for 3 min until the solution is uniform. Then pour it into the carbon powder solution in step (2) and stir for 4 h to make the mixture uniform.

[0050] (4) Add 100 mL of ethylene glycol to the mixed solution in step (3), stir for 15 min, and then add 170 μL of NaOH solution with a molar concentration of 5 mol / L.

[0051] (5) Place the reaction system in step (4) in an oil bath, heat at 80°C for 4 h, and then cool to room temperature and wash with deionized water for 6 times.

[0052] (6) Place the product in a drying box, dry at 60°C for 14 h, then grind into powder using a mortar and collect for use.

[0053] Example 3:

[0054] (1) Take 0.5 g of Ketjenblack ECP600JD carbon powder and 3 g of phenylboronic acid, mix and grind in a marble mortar for 40 min. After grinding, test the mixture using a laser particle size analyzer, and measure the particle size distribution D50=45 μm. Transfer the obtained uniform mixture to a porcelain boat, and place it in a tube furnace under an inert gas protection atmosphere, heat to 600°C at a heating rate of 5°C / min, and keep the temperature constant for 3 h. After cooling to room temperature, a boron-doped carbon carrier is obtained, denoted as 6B@ECP600.

[0055] (2) Take 0.5 g of the boron-doped carbon powder in step (1) into a 500 mL three-necked round-bottom flask, add 80 mL of deionized water, stir for 10 min, and then place it in an ultrasonic cleaner for 30 min to uniformly disperse the carbon powder in water.

[0056] (3) Take 334 mg of chloroplatinic acid into a beaker, add 20 mL of deionized water, and ultrasonic for 3 min until the solution is uniform. Pour it into the carbon powder solution in step (2), and stir for 4 h to make the mixture uniform.

[0057] (4) Add 100 mL of ethylene glycol to the mixed solution in step (3), stir for 15 min, and then add 180 μL of NaOH solution with a molar concentration of 5 mol / L.

[0058] (5) Place the reaction system in step (4) in an oil bath, heat at 80°C for 4 h, and then wash it with deionized water for 6 times after cooling to room temperature.

[0059] (6) Place the product in a drying box, dry at 60°C for 14 h, take it out, grind it into powder using a mortar, and then collect it for use.

[0060] Comparative Example 1:

[0061] (1) Take 0.5 g of Ketjenblack ECP600JD carbon powder into a 500 mL three-necked round-bottom flask, add 80 mL of deionized water, stir for 10 min, and then place it in an ultrasonic cleaner for 30 min to uniformly disperse the carbon powder in water.

[0062] (2) Take 334 mg of chloroplatinic acid into a beaker, add 20 mL of deionized water, and ultrasonic for 3 min until the solution is uniform. Pour it into the carbon powder solution in step (1), and stir for 4 h to make the mixture uniform.

[0063] (3) Add 100 mL of ethylene glycol to the mixed solution in step (2), stir for 15 min, and then add 150 μL of NaOH solution with a molar concentration of 5 mol / L.

[0064] (4) The reaction system in step (3) is placed on an oil bath, heated at 80°C for 4 h, and then washed with deionized water for 6 times after cooling to room temperature.

[0065] (5) The product is placed in a drying oven, dried at 60°C for 14 h, taken out, ground into powder with a mortar, and then collected for use.

[0066] Comparative Example 2:

[0067] (1) 0.5 g Cabot BP2000 carbon powder is weighed into a 500 mL three-necked round-bottom flask, 80 mL deionized water is added, stirred for 10 min, and then placed in an ultrasonic cleaner for ultrasonic treatment for 30 min to uniformly disperse the carbon powder in water.

[0068] (2) 334 mg chloroplatinic acid is weighed into a beaker, 20 mL deionized water is added, ultrasonic treatment is performed for 3 min until the solution is uniform, and then poured into the carbon powder solution in step (1), and stirred for 4 h to make the mixture uniform.

[0069] (3) 100 mL ethylene glycol is added to the mixed solution in step (2), stirred for 15 min, and then 150 μL of 5 mol / L NaOH solution is added.

[0070] (4) The reaction system in step (3) is placed on an oil bath, heated at 80°C for 4 h, and then washed with deionized water for 6 times after cooling to room temperature.

[0071] (5) The product is placed in a drying oven, dried at 60°C for 14 h, taken out, ground into powder with a mortar, and then collected for use.

[0072] Figure 1 The figure is a schematic diagram of the preparation method of the boron-doped platinum-carbon catalyst. First, the boron-doped carbon carrier prepared is characterized. XPS quantitative analysis confirms that the boron element has been successfully doped into the carbon matrix, and as the ratio of phenylboronic acid in the precursor increases from 1:1.5 to 1:6, the proportion of boron atoms in the carrier also increases (Table 1). Figure 2 The FTIR spectrum of the related sample in Example 1 provides evidence for the chemical bonding of boron atoms observed in the doped carrier. Combined with the XRD spectrum of Figure 3 , the results show that the doped carbon carrier maintains similar structural characteristics to the original carrier, and the main diffraction peak does not change significantly, proving that the doping process adopted in the present application effectively avoids the destruction of the carbon skeleton structure by high temperature while introducing boron elements, successfully maintaining the basic integrity of the carbon skeleton, providing stable support for subsequent loading of platinum metal.

[0073]

[0074] Further analyze the pore structure of the prepared carbon carrier, Figure 4 The nitrogen adsorption desorption curve and pore size distribution graph of the boron-doped carbon carrier prepared for the embodiment 1 of the present application, and the related characterization parameters are summarized in Table 1. The test results show that although the specific surface area of the carbon carrier after doping is slightly lower than that of the original carrier, it can still be maintained at a high level. Based on the above analysis, the preparation method provided by the present application can realize effective doping of boron elements without significantly sacrificing the structural characteristics of the carbon carrier.

[0075] On the basis of obtaining the boron-doped carbon carrier, the structure of the boron-doped platinum carbon catalyst prepared in the embodiment is characterized and the performance is evaluated. Figure 5 The XRD diffraction pattern of the prepared catalyst sample is shown in Table 2. All samples show typical platinum crystal diffraction peaks, which are consistent with the structural characteristics of platinum carbon catalysts, and the average particle size of the nanoparticles is in the range of 2-3 nm. The synthesized catalysts were also tested for electrochemical performance. The average particle size of the catalysts prepared in Examples 1-3 and the detailed results of the electrochemical test are as follows:

[0076]

[0077] The boron doping enhances the electronic interaction between platinum and the carbon carrier, effectively inhibits the migration and agglomeration of platinum precursors during the reduction process, and is conducive to the formation of smaller and more uniform active sites. As can be seen from Table 2, the platinum carbon catalysts synthesized after doping boron can maintain an average particle size of less than 3 nm, and their catalytic performance and stability after 2000 cycles of durability test are better than those of the undoped catalysts.

[0078] The above embodiments are used to illustrate the inventive intent and embodiments of the present application, but those skilled in the art of the present application can understand that the above embodiments of the present application are only one of the preferred embodiments of the present application, and due to the limitation of the length of the article, all embodiments cannot be listed one by one, any embodiment that can embody the technical solution of the claims of the present application is within the protection scope of the present application.

[0079] It should be noted that the above content is a further detailed description of the present application in combination with specific embodiments, and the specific embodiments of the present application cannot be limited to this. Under the guidance of the above embodiments, those skilled in the art can make various improvements and modifications on the basis of the above embodiments, and these improvements or modifications fall within the protection scope of the present application.

Claims

1. A method for preparing boron-doped carbon support for proton exchange membrane electrolysis water cathode hydrogen evolution reaction, characterized in that, The method comprises the following steps: The porous carbon material is mixed with phenylboronic acid at a mass ratio of 1:(1.5-6) and mechanically ground to a particle size D50≤100 μm, and then calcined at 600-900 ℃ for 2-4 hours under the protection of inert gas to obtain the boron-doped carbon carrier; in the boron-doped carbon carrier, the boron element is mainly doped in the carbon skeleton in the form of chemical bonding.

2. The method for preparing boron-doped carbon support for hydrogen evolution reaction of proton exchange membrane electrolysis water cathode according to claim 1, characterized in that: The porous carbon material is selected from one of Ketjen Black ECP600JD, Ketjen Black EC600JD, Ketjen Black EC300J and Cabot BP2000.

3. The method for preparing boron-doped carbon support for hydrogen evolution reaction of proton exchange membrane electrolysis water cathode according to claim 1, characterized in that: The heating rate of the calcination is 3-8 ℃ / min.

4. A boron-doped carbon support for the hydrogen evolution reaction of a proton exchange membrane electrolysis water cathode, characterized by: The boron-doped carbon carrier prepared by the method of any one of claims 1-3, wherein the boron element is mainly doped in the carbon skeleton in the form of chemical bonding, the atomic percentage content of the boron element is 6-11 at%, and the specific surface area of the boron-doped carbon carrier is 900-1500 m² / g.

5. A method for producing a boron-doped platinum carbon catalyst, characterized by, The method comprises the following steps: The boron-doped carbon carrier is prepared by the method of any one of claims 1-3; and loading platinum nanoparticles on the boron-doped carbon carrier, wherein the method for loading the platinum nanoparticles is a liquid-phase reduction method, which comprises the following steps: mixing and dispersing the boron-doped carbon carrier with a platinum precursor solution, adding an alcohol solution, adjusting the pH to 7-10 with an alkali solution, heating and reducing the metal precursor, and performing filtration, washing and drying treatment on the product after the heating and reduction to obtain the boron-doped platinum-carbon catalyst.

6. The method for preparing a boron-doped platinum-carbon catalyst as described in claim 5, characterized in that: The heating and reduction of the metal precursor is performed at 70-90 ℃ for 3-5 hours; the platinum precursor is at least one of chloroplatinic acid, platinum tetrachloride and potassium chloroplatinate; the alcohol solution is at least one of ethylene glycol, ethanol and glycerol, and the volume ratio of alcohol to water is 1:1; and the alkali solution is a sodium hydroxide solution or a potassium hydroxide solution.

7. A boron-doped platinum carbon catalyst characterized in that, The boron-doped platinum-carbon catalyst is prepared by the method of any one of claims 5 or 6.

8. The boron-doped platinum carbon catalyst of claim 7, wherein: The boron-doped platinum carbon catalyst has a hydrogen evolution overpotential of ≤ 85.2 mV at a current density of 10 mA·cm -2 -85.2 mV at a current density of 10 mA·cm -1 Pt; the platinum loading in the boron-doped platinum carbon catalyst is 20 wt%, and the average platinum particle size is 2-3 nm.

9. The boron-doped platinum-carbon catalyst of claim 7 is used in the hydrogen evolution reaction of a proton exchange membrane electrolysis water cathode.

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