CN114725409B - Platinum-nickel nanocrystalline modified carbon-based catalyst, gram-grade low-pressure preparation method and application thereof - Google Patents

Abstract

The present invention discloses a platinum-nickel nanocrystal modified carbon-based catalyst and a gram-level low-pressure preparation method and application thereof. The gram-level low-pressure preparation method comprises: reacting a mixed reaction system comprising a platinum precursor, a nickel precursor, carbon black, a stabilizer, a structure directing agent and a solvent at 130-210° C. under normal pressure for 12 hours to obtain a platinum-nickel nanocrystal modified carbon-based catalyst. The oxygen reduction reaction performance of the platinum-nickel nanocrystal modified carbon-based catalyst prepared by the present invention is significantly improved. At the same time, the platinum-nickel nanocrystal modified carbon-based catalyst can be synthesized under normal pressure, has the advantages of low platinum content, excellent oxygen reduction performance, high stability, and can be produced and prepared at the gram level, which can greatly reduce the production cost and has a very broad prospect for industrial application.

Description

Platinum-nickel nanocrystal modified carbon-based catalyst and its gram-scale low-pressure preparation method and application

Technical Field

The invention belongs to the technical field of material and energy catalysis, and specifically relates to a platinum-nickel nanocrystal-modified carbon-based catalyst and a gram-level low-pressure preparation method and application thereof.

Background Art

Proton exchange membrane fuel cells (PEMFCs) are clean energy with great potential, but their performance is greatly limited by the oxygen reduction reaction (ORR). Fuel cells have always been considered the most efficient and cleanest energy conversion devices. Fuel and oxygen react through a mild electrochemical process without combustion. The huge chemical energy contained in hydrogen or hydrocarbons can be directly converted into clean, stable and sustainable electricity through electrochemical pathways at near room temperature. Therefore, they are regarded as one of the most promising solutions to meet the growing world energy needs. However, in practical applications, low-temperature fuel cells do not show such efficiency, mainly due to the slow oxygen reduction reaction at the cathode. In a typical hydrogen fuel cell, hydrogen is oxidized at the positive electrode and oxygen is reduced at the negative electrode. From a kinetic point of view, the oxygen reduction reaction is slower than the hydrogen oxidation reaction, so the oxygen reduction reaction has become an important factor restricting the development of fuel cells. Among many catalysts, precious metal platinum-based catalysts have extremely high activity in the ORR reaction and have broad application prospects. However, there are some defects in the widespread use of platinum-based catalysts in fuel cells. The main reason is that the supply of platinum is very limited, the price is high, and batch preparation is difficult, making it unsuitable for large-scale industrial applications. Therefore, the rational design of platinum-based catalysts with low platinum loading and high stability, as well as preparation methods that can synthesize products on a large scale are of great significance in practical applications.

By doping with different metals, not only will the electronic structure of the precious metal platinum be changed, making it have better oxygen reduction reaction performance. And loading platinum-nickel nanocrystalline particles on a highly active carbon carrier can reduce the content of precious metal platinum while increasing the electron transfer rate during the reaction. This synthesis method is simple and convenient. Under the action of a stabilizer, the output of the catalyst can be increased to the gram level at normal pressure, and the oxygen reduction reaction performance is improved at a low platinum content. This technology can increase the output of the catalyst from the milligram level to the gram level, and the low platinum content greatly reduces the production cost of platinum-based catalysts, providing a certain basis for the large-scale commercial application of fuel cells.

Summary of the invention

The main purpose of the present invention is to provide a platinum-nickel nanocrystal modified carbon-based catalyst and a gram-level low-pressure preparation method and application thereof, so as to overcome the shortcomings of the prior art.

In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

An embodiment of the present invention provides a gram-level low-pressure preparation method for a platinum-nickel nanocrystal modified carbon-based catalyst, which comprises: reacting a mixed reaction system comprising a platinum precursor, a nickel precursor, carbon black, a stabilizer, a structure directing agent and a solvent at 130-210° C. and normal pressure for 12 hours to obtain a platinum-nickel nanocrystal modified carbon-based catalyst.

The embodiment of the present invention also provides a platinum-nickel nanocrystal modified carbon-based catalyst prepared by the aforementioned gram-level low-pressure preparation method, wherein the particle size of the PtNi particles in the platinum-nickel nanocrystal modified carbon-based catalyst is 3 to 4 nm; the Pt content in the platinum-nickel nanocrystal modified carbon-based catalyst is 3.00 to 3.36 wt%.

The embodiment of the present invention also provides the use of the aforementioned platinum-nickel nanocrystal modified carbon-based catalyst in the preparation of a fuel cell.

Compared with the prior art, the present invention has the following beneficial effects:

(1) In the present invention, under the action of a structure directing agent and a stabilizer, a platinum-nickel precursor is loaded on a carbon-based carrier, and the PtNi particle size of the synthesized platinum-nickel nanocrystal modified carbon-based catalyst is 3-4 nm, and the platinum content is only 3.00-3.36 wt %. In addition, the specific activity of the platinum-nickel nanocrystal modified carbon-based catalyst in the oxygen reduction reaction is 9.28 and 6.47 times that of the commercial Pt/C-5% (Pt content is 5%) and Pt/C-20% (Pt content is 20%) catalysts, respectively;

(2) The platinum-nickel nanocrystal-modified carbon-based catalyst in the present invention can be produced under normal pressure, has the advantages of low platinum content, excellent oxygen reduction performance, high stability, and can be produced and prepared at the gram level, which can greatly reduce the production cost and has a very broad prospect for industrial application.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a scanning electron micrograph of a platinum-nickel nanocrystal-modified carbon-based catalyst PtNi/C in Example 1;

FIG2 is a transmission electron micrograph of the carbon-based catalyst PtNi/C modified with platinum-nickel nanocrystals in Example 1;

FIG3 is an XRD spectrum of the carbon-based catalyst PtNi/C modified with platinum-nickel nanocrystals in Example 1;

FIG4 is a schematic diagram of a gram-scale synthesis preparation device in Example 1;

5 is a graph showing the results of oxygen reduction reaction performance tests of the PtNi/C catalysts synthesized at different temperatures in alkaline solutions (0.1 M potassium hydroxide) in Examples 1-6 of the present invention;

6 is a graph showing the results of oxygen reduction reaction performance tests of PtNi/C catalysts synthesized with different platinum-nickel ratios in Examples 7-11 of the present invention in an alkaline solution (0.1 M potassium hydroxide);

7 is a graph showing the oxygen reduction reaction performance of PtNi/C-200°C-Pt:Ni=1:2 in Example 10 of the present invention and commercial Pt/C-5% and commercial Pt/C-20% in Comparative Example 1;

FIG8 is a transmission electron micrograph of the catalyst prepared in Comparative Example 2 of the present invention;

FIG9 is a transmission electron micrograph of the catalyst prepared in Comparative Example 3 of the present invention;

FIG10 is a transmission electron micrograph of the catalyst prepared in Comparative Example 4 of the present invention;

FIG. 11 is a graph showing the oxygen reduction reaction performance test of the catalysts prepared in Comparative Examples 2-4 of the present invention.

DETAILED DESCRIPTION

In view of the defects of the prior art, the inventors of this case have proposed the technical solution of the present invention after long-term research and extensive practice. In order to solve the problem of high preparation cost of existing commercial platinum-based catalysts, the present invention discloses a gram-level low-pressure preparation method of a carbon-based catalyst modified with platinum-nickel nanocrystals. The synthesis method can achieve gram-level preparation of catalysts at room temperature, and the carbon base is modified by platinum-nickel nanocrystals with low platinum loading, thereby achieving excellent catalytic performance. The preparation method is simple and easy, and the synthesized nanocrystals have a size of 3-4nm, are evenly dispersed on the carbon-based carrier, and have extremely high stability.

By using the subgroup element nickel and the precious metal platinum to form an alloy, the electronic structure of the precious metal platinum is changed, and the catalytic performance of the precious metal platinum in the oxygen reduction reaction process is improved; nickel and platinum form an alloy and are loaded on a carbon carrier, so that the distribution of the formed alloy is more uniform, the utilization rate of platinum atoms is improved, and the content of precious metal platinum in the oxygen reduction catalyst is effectively reduced, thereby reducing the cost of industrial application. Under the action of benzoic acid and hexadecyltrimethylammonium bromide, stable platinum-nickel nanocrystals with small size and not easy to aggregate can be formed under normal pressure. Through this synthesis method, the output of the catalyst is increased from milligrams to grams, which is of great significance for the further commercial application of fuel cells.

The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Specifically, as one aspect of the technical solution of the present invention, a gram-level low-pressure preparation method of a platinum-nickel nanocrystal modified carbon-based catalyst involves: reacting a mixed reaction system comprising a platinum precursor, a nickel precursor, carbon black, a stabilizer, a structure directing agent and a solvent at 130-210°C under normal pressure for 12 hours to obtain a platinum-nickel nanocrystal modified carbon-based catalyst.

In some preferred embodiments, the gram-scale low-pressure preparation method comprises: dispersing a platinum precursor, a nickel precursor, carbon black, a stabilizer, and a structure directing agent in a solvent to form the mixed reaction system.

In some preferred embodiments, the platinum precursor includes platinum acetylacetonate and/or potassium tetrachloroplatinate, but is not limited thereto.

In some preferred embodiments, the nickel precursor includes nickel acetylacetonate and/or nickel chloride, but is not limited thereto.

In some preferred embodiments, the stabilizer includes benzoic acid, but is not limited thereto.

In some preferred embodiments, the structure directing agent includes hexadecyltrimethylammonium bromide, wherein the hexadecyltrimethylammonium bromide functions to stabilize PtNi nanocrystals and control their particle size to form PtNi nanoparticles of smaller size.

In some preferred embodiments, the carbon black includes any one of Vulcan XC-72, Ketjen black, and acetylene black, or a combination of two or more thereof, but is not limited thereto.

In some preferred embodiments, the solvent includes benzyl alcohol, but is not limited thereto.

In some preferred embodiments, the mass ratio of the platinum precursor to the nickel precursor is 3:1 to 1:3.

In some preferred embodiments, the mass ratio of the carbon black to the platinum precursor is 11.25:1.

In some preferred embodiments, the mass ratio of the stabilizer to the platinum precursor is 6.25:1.

In some preferred embodiments, the mass ratio of the structure directing agent to the platinum precursor is 10.00:1.

In some preferred embodiments, the gram-scale low-pressure preparation method further comprises: after the reaction is completed, washing, centrifuging and drying the obtained product.

Furthermore, the obtained product is washed with ethanol and acetone and centrifuged.

In some more specific embodiments, the gram-scale low-pressure preparation method of the platinum-nickel nanocrystal modified carbon-based catalyst comprises:

(1) weighing different proportions of platinum precursor and nickel precursor, stirring at room temperature to form a uniform solution under the action of a stabilizer and a structure directing agent;

(2) placing the solution of step (1) in an oil bath, setting the reaction temperature, and preparing a sample under normal pressure;

(3) adding ethanol and acetone to the sample synthesized in step (2) to wash and centrifuge the sample;

(4) The sample obtained by centrifugation in step (3) is placed in a vacuum drying oven for drying to obtain a platinum-nickel nanocrystal-modified carbon-based catalyst.

Furthermore, in step (2), the reaction temperature is any one of 130°C, 150°C, 170°C, 190°C, 200°C or 210°C.

Another aspect of an embodiment of the present invention further provides a platinum-nickel nanocrystal-modified carbon-based catalyst prepared by the aforementioned gram-level low-pressure preparation method, wherein the particle size of the PtNi particles in the platinum-nickel nanocrystal-modified carbon-based catalyst is 3 to 4 nm; the Pt content in the platinum-nickel nanocrystal-modified carbon-based catalyst is 3.00 to 3.36 wt%, preferably 3.04%.

Another aspect of the embodiments of the present invention further provides the use of the aforementioned platinum-nickel nanocrystal modified carbon-based catalyst in the preparation of a fuel cell.

The technical solution of the present invention is further described in detail below in conjunction with several preferred embodiments and drawings. This embodiment is implemented on the premise of the technical solution of the invention, and a detailed implementation method and specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

Unless otherwise specified, the experimental materials used in the following examples can be purchased from conventional biochemical reagent companies.

Example 1

(1) Dissolve 90 mg of carbon black (Vulcan XC-72), 10.28 mg of nickel acetylacetonate, 80 mg of hexadecyltrimethylammonium bromide, 50 mg of benzoic acid, and 8 mg of platinum acetylacetonate in 5 mL of solvent and stir until the solution is uniform. Then transfer the solution to an oil bath and react at 130°C for 12 h.

(2) washing the product synthesized in step (1) with ethanol and acetone, and then centrifuging to separate the solid product;

(3) The sample synthesized in step (2) was dried in a drying oven for 12 hours to obtain a platinum-nickel nanocrystal modified carbon-based catalyst PtNi/C (recorded as: synthesized PtNi/C-130°C). The synthesized PtNi/C catalyst at this temperature has a better catalytic performance for oxygen reduction reaction. The yield of the PtNi/C catalyst in this example is 1.15 g.

Figure 1 is a scanning electron micrograph of the platinum-nickel nanocrystal-modified carbon-based catalyst PtNi/C in this embodiment; Figure 2 is a transmission electron micrograph of the platinum-nickel nanocrystal-modified carbon-based catalyst PtNi/C in this embodiment; Figure 3 is an XRD spectrum of the platinum-nickel nanocrystal-modified carbon-based catalyst PtNi/C in this embodiment; Figure 4 is a schematic diagram of the gram-level synthesis preparation device in this embodiment.

Example 2

(1) Dissolve 90 mg of carbon black (Vulcan XC-72), 10.28 mg of nickel acetylacetonate, 80 mg of hexadecyltrimethylammonium bromide, 50 mg of benzoic acid, and 8 mg of platinum acetylacetonate in 5 mL of solvent and stir until the solution is uniform. Then transfer the solution to an oil bath and react at 150°C for 12 h.

(2) washing the product synthesized in step (1) with ethanol and acetone, and then centrifuging to separate the solid product;

(3) The sample synthesized in step (2) was dried in a drying oven for 12 hours to obtain a platinum-nickel nanocrystal-modified carbon-based catalyst PtNi/C (recorded as: synthesized PtNi/C-150°C). The PtNi/C catalyst synthesized at this temperature has a better catalytic performance for oxygen reduction reaction.

Example 3

(1) Dissolve 90 mg of carbon black (Vulcan XC-72), 10.28 mg of nickel acetylacetonate, 80 mg of hexadecyltrimethylammonium bromide, 50 mg of benzoic acid, and 8 mg of platinum acetylacetonate in 5 mL of solvent and stir until the solution is uniform. Then transfer the solution to an oil bath and react at 170°C for 12 h.

(2) washing the product synthesized in step (1) with ethanol and acetone, and then centrifuging to separate the solid product;

(3) The sample synthesized in step (2) was dried in a drying oven for 12 hours to obtain a platinum-nickel nanocrystal-modified carbon-based catalyst PtNi/C (recorded as: synthesized PtNi/C-170°C). The PtNi/C catalyst synthesized at this temperature has a better catalytic performance for oxygen reduction reaction.

Example 4

(1) Dissolve 90 mg of carbon black (Vulcan XC-72), 10.28 mg of nickel acetylacetonate, 80 mg of hexadecyltrimethylammonium bromide, 50 mg of benzoic acid, and 8 mg of platinum acetylacetonate in 5 mL of solvent and stir until the solution is uniform. Then transfer the solution to an oil bath and react at 190°C for 12 h.

(2) washing the product synthesized in step (1) with ethanol and acetone, and then centrifuging to separate the solid product;

(3) The sample synthesized in step (2) was dried in a drying oven for 12 hours to obtain a platinum-nickel nanocrystal-modified carbon-based catalyst PtNi/C (recorded as: synthesized PtNi/C-190°C). The PtNi/C catalyst synthesized at this temperature has a better catalytic performance for oxygen reduction reaction.

Example 5

(1) Dissolve 90 mg of carbon black (Vulcan XC-72), 10.28 mg of nickel acetylacetonate, 80 mg of hexadecyltrimethylammonium bromide, 50 mg of benzoic acid, and 8 mg of platinum acetylacetonate in 5 mL of solvent and stir until the solution is uniform. Then transfer the solution to an oil bath and react at 200°C for 12 h.

(2) washing the product synthesized in step (1) with ethanol and acetone, and then centrifuging to separate the solid product;

(3) Dry the sample synthesized in step (2) in a drying oven for 12 hours to obtain a platinum-nickel nanocrystal-modified carbon-based catalyst PtNi/C (denoted as: synthesized PtNi/C-200°C). The PtNi/C catalyst synthesized at this temperature has better catalytic performance for oxygen reduction reaction.

Example 6

(1) Dissolve 90 mg of carbon black (Vulcan XC-72), 10.28 mg of nickel acetylacetonate, 80 mg of hexadecyltrimethylammonium bromide, 50 mg of benzoic acid, and 8 mg of platinum acetylacetonate in 5 mL of solvent and stir until the solution is uniform. Then transfer the solution to an oil bath and react at 210°C for 12 h.

(2) washing the product synthesized in step (1) with ethanol and acetone, and then centrifuging to separate the solid product;

(3) Dry the sample synthesized in step (2) in a drying oven for 12 hours to obtain a platinum-nickel nanocrystal-modified carbon-based catalyst PtNi/C (denoted as: synthesized PtNi/C-210°C). The PtNi/C catalyst synthesized at this temperature has better catalytic performance for oxygen reduction reaction.

Figure 5 is the results of the oxygen reduction reaction performance test of the PtNi/C catalyst synthesized at different temperatures in Examples 1-6 of the present invention in an alkaline solution (0.1M potassium hydroxide). By comparison, it was found that when the temperature increased from 130°C to 200°C, as the temperature increased during the synthesis of the sample, the results of the catalytic oxygen reduction reaction performance test became better. When the temperature was raised to 210°C, the temperature during the synthesis of the sample had a slightly worse oxygen reduction reaction performance than the PtNi/C catalyst synthesized at 200°C, but it still had excellent catalytic activity for the oxygen reduction reaction. Therefore, the PtNi/C catalyst synthesized at 200°C is the optimal temperature for the synthesis of the sample.

The PtNi/C catalysts synthesized at different temperatures in the present invention show excellent catalytic performance for oxygen reduction reaction in an acidic solution (0.1M perchloric acid). And under the different temperatures investigated (130°C, 150°C, 170°C, 190°C, 200°C, or 210°C), the synthesized catalysts all show excellent catalytic activity for oxygen reduction reaction.

Example 7

(1) Dissolve 90 mg of carbon black (Vulcan XC-72), 1.742 mg of nickel acetylacetonate, 80 mg of hexadecyltrimethylammonium bromide, 50 mg of benzoic acid, and 8 mg of platinum acetylacetonate in 5 mL of benzyl alcohol and stir until the solution is uniform. Then transfer the solution to an oil bath and react at 200°C for 12 h.

(2) washing the product synthesized in step (1) with ethanol and acetone, and then centrifuging to separate the solid product;

(3) The sample synthesized in step (2) was dried in a drying oven for 12 hours to obtain a platinum-nickel nanocrystal modified carbon-based catalyst PtNi/C (recorded as: synthesized PtNi/C-200°C-Pt:Ni=3:1). The composition of the platinum-nickel nanocrystal modified carbon-based catalyst PtNi/C is shown in Table 1.

Example 8

(1) Dissolve 90 mg of carbon black (Vulcan XC-72), 2.613 mg of nickel acetylacetonate, 80 mg of hexadecyltrimethylammonium bromide, 50 mg of benzoic acid, and 8 mg of platinum acetylacetonate in 5 mL of benzyl alcohol and stir until the solution is uniform. Then transfer the solution to an oil bath and react at 200°C for 12 h.

(2) washing the product synthesized in step (1) with ethanol and acetone, and then centrifuging to separate the solid product;

(3) The sample synthesized in step (2) was dried in a drying oven for 12 hours to obtain a platinum-nickel nanocrystal modified carbon-based catalyst PtNi/C (recorded as: synthesized PtNi/C-200°C-Pt:Ni=2:1). The composition of the platinum-nickel nanocrystal modified carbon-based catalyst PtNi/C is shown in Table 1.

Example 9

(1) Dissolve 90 mg of carbon black (Vulcan XC-72), 5.203 mg of nickel acetylacetonate, 80 mg of hexadecyltrimethylammonium bromide, 50 mg of benzoic acid, and 8 mg of platinum acetylacetonate in 5 mL of benzyl alcohol and stir until the solution is uniform. Then transfer the solution to an oil bath and react at 200°C for 12 h.

(2) washing the product synthesized in step (1) with ethanol and acetone, and then centrifuging to separate the solid product;

(3) The sample synthesized in step (2) was dried in a drying oven for 12 hours to obtain a platinum-nickel nanocrystal modified carbon-based catalyst PtNi/C (recorded as: synthesized PtNi/C-200°C-Pt:Ni=1:1). The composition of the platinum-nickel nanocrystal modified carbon-based catalyst PtNi/C is shown in Table 1.

Example 10

(1) Dissolve 90 mg of carbon black (Vulcan XC-72), 10.451 mg of nickel acetylacetonate, 80 mg of hexadecyltrimethylammonium bromide, 50 mg of benzoic acid, and 8 mg of platinum acetylacetonate in 5 mL of benzyl alcohol and stir until the solution is uniform. Then transfer the solution to an oil bath and react at 200°C for 12 h.

(2) washing the product synthesized in step (1) with ethanol and acetone, and then centrifuging to separate the solid product;

(3) The sample synthesized in step (2) was dried in a drying oven for 12 hours to obtain a platinum-nickel nanocrystal modified carbon-based catalyst PtNi/C (recorded as: synthesized PtNi/C-200°C-Pt:Ni=1:2). The composition of the platinum-nickel nanocrystal modified carbon-based catalyst PtNi/C is shown in Table 1.

Embodiment 11

(1) Dissolve 90 mg of carbon black (Vulcan XC-72), 15.677 mg of nickel acetylacetonate, 80 mg of hexadecyltrimethylammonium bromide, 50 mg of benzoic acid, and 8 mg of platinum acetylacetonate in 5 mL of benzyl alcohol and stir until the solution is uniform. Then transfer the solution to an oil bath and react at 200°C for 12 h.

(2) washing the product synthesized in step (1) with ethanol and acetone, and then centrifuging to separate the solid product;

(3) The sample synthesized in step (2) was dried in a drying oven for 12 hours to obtain a platinum-nickel nanocrystal modified carbon-based catalyst PtNi/C (recorded as: synthesized PtNi/C-200°C-Pt:Ni=1:3). The composition of the platinum-nickel nanocrystal modified carbon-based catalyst PtNi/C is shown in Table 1.

Table 1 Composition of the platinum-nickel nanocrystal-modified carbon-based catalyst prepared in Examples 7-11

Figure 6 is the result of the oxygen reduction reaction performance test of the PtNi/C catalyst synthesized by different platinum-nickel ratios in Examples 7-11 of the present invention in an alkaline solution (0.1M potassium hydroxide). By comparison, it was found that when the platinum-nickel ratio increased from 3:1 to 1:2, as the platinum-nickel ratio increased during the synthesis of the sample, the result of the catalytic oxygen reduction reaction performance test was better. When the platinum-nickel ratio increased to 1:3, the platinum-nickel ratio during the synthesis of the sample had a slightly worse oxygen reduction reaction performance than the PtNi/C catalyst synthesized at 1:2. Therefore, the PtNi/C catalyst synthesized at a platinum-nickel ratio of 1:2 is the optimal platinum-nickel ratio for the synthetic sample.

Comparative Example 1

Commercial Pt/C-5% and commercial Pt/C-20% were used to test the oxygen reduction reaction performance;

7 is a test graph of the oxygen reduction reaction performance of PtNi/C-200°C-Pt∶Ni＝1∶2 in Example 10 of the present invention, commercial Pt/C-5% and commercial Pt/C-20% in Comparative Example 1.

Comparative Example 2

The method is the same as Example 10, except that the stabilizer benzoic acid is not used; FIG8 is a transmission electron micrograph of the catalyst prepared in this comparative example 2.

Comparative Example 3

The method is the same as Example 10, except that the structure directing agent hexadecyltrimethylammonium bromide is not used; FIG. 9 is a transmission electron micrograph of the catalyst prepared in this comparative example 3.

Comparative Example 4

The method is the same as Example 10, except that the stabilizer benzoic acid and the structure-directing agent hexadecyltrimethylammonium bromide are not used; Figure 10 is a transmission electron micrograph of the catalyst prepared in this comparative example 4; Figure 11 is a test graph of the oxygen reduction reaction performance of the catalyst prepared in this comparative example 2-4.

In addition, the inventors of this case also referred to the aforementioned embodiments and conducted experiments with other raw materials, process operations, and process conditions described in this specification, and obtained relatively ideal results.

It should be understood that the technical solution of the present invention is not limited to the above-mentioned specific implementation cases. Any technical deformation made according to the technical solution of the present invention without departing from the scope of protection of the purpose of the present invention and the claims shall fall within the protection scope of the present invention.

Claims (8)

1. A gram-sized low-pressure preparation method of a platinum-nickel nanocrystalline modified carbon-based catalyst, which is characterized by comprising the following steps: reacting a mixed reaction system containing a platinum precursor, a nickel precursor, carbon black, a stabilizer, a structure directing agent and a solvent at the normal pressure of 130-210 ^o ℃ for 12 hours to prepare a platinum-nickel nanocrystalline modified carbon-based catalyst; wherein the platinum precursor is selected from platinum acetylacetonate; the nickel precursor is selected from nickel acetylacetonate; the stabilizer is selected from benzoic acid; the structure directing agent is selected from cetyl trimethyl ammonium bromide; the mass ratio of the platinum precursor to the nickel precursor is 3:1-1:3; the mass ratio of the carbon black to the platinum precursor is 11.25:1; the mass ratio of the stabilizer to the platinum precursor is 6.25:1; the mass ratio of the structure directing agent to the platinum precursor is 10.00:1;

The particle size of PtNi particles in the platinum-nickel nanocrystalline modified carbon-based catalyst is 3-4 nm; the Pt content of the platinum-nickel nanocrystalline modified carbon-based catalyst is 3.00-3.36wt%.

2. The gram-scale low pressure process of claim 1, comprising: dispersing a platinum precursor, a nickel precursor, carbon black, a stabilizing agent and a structure directing agent in a solvent to form the mixed reaction system.

3. The gram-scale low pressure process of claim 1, wherein: the carbon black is selected from any one or more than two of Vulcan XC-72, ketjen black and acetylene black.

4. The gram-scale low pressure process of claim 1, wherein: the solvent is selected from benzyl alcohol.

5. The gram-scale low pressure process of claim 1, further comprising: after the reaction is completed, the obtained product is washed, centrifuged and dried.

6. The gram-grade low-pressure preparation method as claimed in claim 5, wherein the obtained product is washed and centrifuged by ethanol and acetone.

7. A platinum nickel nanocrystalline modified carbon-based catalyst produced by the gram-grade low-pressure production method of any one of claims 1-6.

8. Use of the platinum nickel nanocrystalline modified carbon-based catalyst according to claim 7 for preparing a fuel cell.