An oxygen reduction electrocatalyst, its preparation method and application

Abstract

The present invention belongs to the field of electrocatalysts, and provides an oxygen reduction electrocatalyst, a preparation method thereof and an application. The preparation method includes: dispersing a platinum source, a non-noble metal source, a dispersant and a carrier in a solvent, drying to obtain a precursor material, and then performing Joule heat treatment on the precursor material to obtain the oxygen reduction electrocatalyst. The preparation method provided by the present invention only needs to simply mix the raw materials and the dispersant and perform Joule heat treatment to obtain oxygen reduction electrocatalysts with different platinum loadings. Moreover, the prepared catalyst has good dispersibility, uniform metal nanoparticle sizes, and exhibits efficient reaction kinetics and lasting stability. The preparation method provided by the present invention is simple, easy to control, and suitable for mass production.

Description

Technical Field

[0001] The present invention belongs to the field of electrocatalysts, and relates to an oxygen reduction electrocatalyst, a preparation method thereof, and an application thereof. Background Art

[0002] Hydrogen-oxygen fuel cells have advantages such as high energy conversion efficiency and clean products. However, the oxygen reduction (ORR) reaction kinetics at the cathode is slow, and platinum or platinum-based catalysts are required to accelerate the reaction. However, the currently used platinum-based catalysts have problems such as poor stability and slow reaction kinetics. Theoretical and experimental studies have shown that platinum-rare earth alloys have significant ORR activity, and platinum-rare earth alloys have an unusually negative alloy formation energy, making them have excellent stability.

[0003] However, the synthesis of platinum-rare earth alloy nanoparticles has always been a huge challenge, mainly because the standard reduction potentials of these two metals differ greatly, and rare earths have a strong affinity for oxygen. Currently, the methods for synthesizing platinum-rare earth alloys are relatively extreme, such as extremely strong reducing agents and high temperatures. These conditions result in larger particle sizes, uneven dispersion, or even uneven distribution of Pt and rare earth elements, and there is a phase separation situation. In addition, these preparation methods are time-consuming and energy-consuming, such as long-term high-temperature calcination using a heating device, reduction with a highly reducing and dangerous reducing agent, or techniques such as high-temperature melting and spinning. More importantly, many existing methods can only prepare catalysts with low platinum loadings. High platinum loadings will cause particle agglomeration and growth. However, low-platinum-loading catalysts will bring many problems during the use of fuel cells. Although there are also some methods for preparing high-platinum-loading catalysts, the methods are complex and have poor universality, and cannot prepare high-loading platinum-rare earth alloys.

[0004] In recent years, the rapidly developing Joule heat technology has the advantage of ultra-fast preparation of catalysts and has become a research hotspot. Although there are existing technologies for preparing platinum-based catalysts using the Joule heat method, its preparation method has poor universality, cannot prepare platinum-rare earth related catalysts, has many restrictions on reaction raw materials, and the stability problem of the catalysts has still not been solved. For example, CN202410299244.8 discloses a high-entropy alloy composite material, a Joule heat preparation method thereof, and an application thereof. However, the catalyst prepared by this method is not a platinum-based catalyst, and the carbon support needs to be oxidized first; CN202010714990.0 discloses an intermetallic compound-carbon nanotube composite material, a preparation method thereof, and an application thereof. However, the non-noble metals in this catalyst do not involve rare earth metals, the support is only limited to carbon nanotubes, and the stability data of this catalyst cannot be verified.

[0005] Therefore, how to develop a mild, controllable, and highly universal preparation method that can achieve the preparation of different platinum loadings and different types of platinum-non-precious metal alloys is a technical problem that needs to be solved urgently. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide an oxygen reduction electrocatalyst, a preparation method thereof and an application. The preparation method provided by the present invention does not require pretreatment of the carrier. Only by simply mixing the raw materials and the dispersant and performing Joule heat treatment, oxygen reduction electrocatalysts with different platinum loadings can be obtained. Moreover, the prepared catalysts have good dispersibility, uniform metal nanoparticle sizes, exhibit efficient reaction kinetics and lasting stability. The preparation method provided by the present invention is simple, easy to control, and suitable for mass production.

[0007] To achieve the purpose of this invention, the following technical solutions are adopted:

[0008] In a first aspect, the present invention provides a preparation method of an oxygen reduction electrocatalyst, which includes: dispersing a platinum source, a non-noble metal source, a dispersant and a carrier in a solvent, drying to obtain a precursor material, and then performing Joule heat treatment on the precursor material to obtain the oxygen reduction electrocatalyst.

[0009] In the present invention, by simultaneously dispersing the platinum source, the non-noble metal source, the dispersant and the carrier in the solvent, and then drying the above solution and performing Joule heat treatment, due to the addition of the dispersant, on the one hand, the platinum source and the non-noble metal source can be evenly distributed on the carrier simultaneously during the mixing process; on the other hand, the dispersant can adsorb on the surfaces of the platinum and non-noble metal particles, changing their surface properties and enhancing their interfacial interaction. This enhanced interaction will affect the electron cloud distribution and energy state of the metal particles during the reduction process, which is beneficial to promoting the transfer of electrons between platinum and non-noble metals, so that the reduction temperatures of the two in the Joule heat reaction are closer, and it is beneficial to obtain a more uniform phase.

[0010] The following are the preferred technical solutions of the present invention, but not the limitations on the technical solutions provided by the present invention. Through the following preferred technical solutions, the technical purpose and beneficial effects of the present invention can be better achieved and realized.

[0011] As a preferred technical solution of the present invention, the molar ratio of platinum in the platinum source, non-noble metal in the non-noble metal source and the dispersant is 1.0:(0.1~3.0):(0.1~4.0), such as 1.0:0.1:0.1, 1.0:0.2:1.0, 1.0:0.3:1.7, 1.0:1.0:2.0, 1.0:1.5:2.5, 1.0:2.0:3.0, 1.0:2.5:3.5 or 1.0:3.0:4.0, etc., but not limited to the listed values. Other unlisted values within this numerical range are equally applicable.

[0012] The mass ratio of platinum in the platinum source to the carrier is (2 to 8):(2 to 8), such as 2:8, 3:7, 4:6, 5:5, 6:4, 7:3 or 8:2, etc., but is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0013] The dispersant includes any one or a combination of at least two of polyvinyl alcohol, ethyl acetate, polyvinylpyrrolidone, cetyltrimethylammonium bromide or dodecyltrimethylammonium chloride.

[0014] The non-noble metal source includes a rare earth metal source and / or a transition metal source.

[0015] The rare earth metal source includes a gadolinium source and / or a lanthanum source.

[0016] In the present invention, using a gadolinium source and / or a lanthanum source is more conducive to the simultaneous reduction of rare earth metals and platinum, and thus more conducive to obtaining an oxygen reduction electrocatalyst with a uniform phase.

[0017] The transition metal source includes any one or a combination of at least two of an iron source, a cobalt source or a nickel source.

[0018] It should be noted that the two elements Y and Sc belong to both rare earth metals and transition metals. For the convenience of understanding the present invention, the present invention classifies the two elements Y and Sc into rare earth metals.

[0019] As a preferred technical solution of the present invention, the molar ratio of platinum in the platinum source, non-noble metal in the non-noble metal source and the dispersant is 1.0:(0.1 to 0.5):(0.5 to 2.0), such as 1.0:0.1:0.5, 1.0:0.2:1.0, 1.0:0.3:1.5, 1.0:0.4:1.8 or 1.0:0.5:2.0, etc., but is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0020] In the present invention, by adjusting the molar ratio of platinum in the platinum source and non-noble metal in the non-noble metal source, catalysts with different platinum and non-noble metal molar ratios can be obtained, and in practical applications, selection can be made according to the required catalyst activity requirements and costs; in addition, by controlling the molar ratio of platinum in the platinum source, non-noble metal in the non-noble metal source and the dispersant within 1.0:(0.1 to 3.0):(0.1 to 4.0), and further controlling it within the range of 1.0:(0.1 to 0.5):(0.5 to 2.0), it is more conducive to promoting the regulation effect of the dispersant on the interface between platinum and non-noble metals, and thus conducive to obtaining a more uniform phase of platinum and non-noble metals.

[0021] The mass ratio of platinum in the platinum source to the support is (3 - 7):(3 - 7), such as 3:7, 4:6, 5:5, 6:4, or 7:3, etc., but not limited to the listed values. Other unlisted values within this numerical range are equally applicable.

[0022] In the present invention, by regulating the mass ratio of platinum in the platinum source to the support, catalysts with different platinum loadings can be obtained. By controlling the mass ratio of the two within the range of (3 - 7):(3 - 7), it is more conducive to the balance of catalyst activity and cost.

[0023] The present invention does not limit the types of the platinum source and the support. Exemplarily, the platinum source includes any one or a combination of at least two of chloroplatinic acid, platinum chloride salt, platinum acetylacetonate, or organic platinum salt; the support includes any one or a combination of at least two of carbon support, oxide support, metal support, or ceramic support.

[0024] As a preferred technical solution of the present invention, the method of dispersion includes ultrasonic treatment.

[0025] The time of the ultrasonic treatment is 20 min - 30 min, such as 20 min, 22 min, 24 min, 25 min, 27 min, 28 min, or 30 min, etc., but not limited to the listed values. Other unlisted values within this numerical range are equally applicable.

[0026] The present invention does not limit the drying method. Exemplarily, the drying includes any one or a combination of at least two of forced air drying, vacuum drying, or freeze drying.

[0027] The temperature of the drying is 60°C - 100°C, such as 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, or 100°C, etc., but not limited to the listed values. Other unlisted values within this numerical range are equally applicable.

[0028] In the present invention, the drying temperature will affect the state of platinum. By controlling the drying temperature within the range of 60°C - 100°C, it can ensure that platinum is not oxidized during drying, thereby avoiding affecting the catalytic activity of the catalyst.

[0029] The time of the drying is 5 h - 7 h, such as 5.0 h, 5.5 h, 6.0 h, 6.5 h, or 7.0 h, etc., but not limited to the listed values. Other unlisted values within this numerical range are equally applicable.

[0030] The temperature of the Joule heat treatment is 500°C to 2500°C, such as 500°C, 700°C, 1000°C, 1200°C, 1500°C, 1800°C, 2000°C, 2200°C or 2500°C, etc., but not limited to the listed values, and other unlisted values within this range are equally applicable.

[0031] The time of the Joule heat treatment is 0.1 s to 1800 s, such as 0.1 s, 1 s, 2 s, 3 s, 4 s, 5 s, 100 s, 500 s, 1000 s, 1500 s or 1800 s, etc., but not limited to the listed values, and other unlisted values within this range are equally applicable.

[0032] The atmosphere of the Joule heat treatment is any one or a combination of at least two of argon, nitrogen, ammonia or hydrogen.

[0033] As a preferred technical solution of the present invention, the temperature of the Joule heat treatment is 700°C to 1200°C, such as 700°C, 800°C, 900°C, 1000°C, 1100°C or 1200°C, etc., but not limited to the listed values, and other unlisted values within this range are equally applicable.

[0034] In the present invention, different Joule heat treatment temperatures can be selected according to the doping amounts of different platinum and non-noble metals. By controlling the temperature of the Joule heat treatment within 500°C to 2500°C, and further within the range of 700°C to 1200°C, the crystal structure, particle size and surface properties of the catalyst can all reach an ideal state, promoting the synergistic effect between platinum and non-noble metals, and further improving the catalytic activity, selectivity and stability of the catalyst.

[0035] The time of the Joule heat treatment is 20 s to 90 s, such as 20 s, 30 s, 40 s, 50 s, 60 s, 70 s, 80 s or 90 s, etc., but not limited to the listed values, and other unlisted values within this range are equally applicable.

[0036] As a preferred technical solution of the present invention, the preparation method includes the following steps:

[0037] According to the molar ratio of platinum in the platinum source, non-noble metal in the non-noble metal source and dispersant of 1.0:(0.1 - 0.5):(0.5 - 2.0), and the mass ratio of platinum in the platinum source to the carrier of (3 - 7):(3 - 7), disperse the platinum source, non-noble metal source, dispersant and carrier in a solvent, ultrasonicate for 20 min to 30 min, then dry at 60°C to 100°C for 5 h to 7 h to obtain a precursor material, and finally perform Joule heat treatment on the precursor material at 700°C to 1200°C for 20 s to 90 s to obtain the oxygen reduction electrocatalyst;

[0038] The non-noble metal source includes a rare earth metal source and / or a transition metal source, and the rare earth metal source includes a gadolinium source and / or a lanthanum source;

[0039] The dispersant includes any one or a combination of at least two of polyvinyl alcohol, ethyl acetate, polyvinylpyrrolidone, cetyltrimethylammonium bromide, or dodecyltrimethylammonium chloride;

[0040] The atmosphere for the Joule heat treatment is any one or a combination of at least two of argon, nitrogen, ammonia, or hydrogen.

[0041] In a second aspect, the present invention provides an oxygen reduction electrocatalyst prepared by the preparation method of the oxygen reduction electrocatalyst as described in the first aspect.

[0042] The catalyst prepared by the preparation method of the present invention has a relatively small average particle size and uniform size of metal particles, has good dispersibility on the carrier, and exhibits efficient reaction kinetics and lasting stability.

[0043] As a preferred technical solution of the present invention, the oxygen reduction electrocatalyst includes a carrier and a platinum-non-noble metal alloy supported on the carrier.

[0044] Based on the total mass of the carrier and the platinum-non-noble metal alloy being 100 wt%, the mass proportion of platinum is 20 wt% to 80 wt%, such as 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt%, or 80 wt%, etc., but is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0045] The molar ratio of platinum to the non-noble metal is 1.0:(0.1 - 3.0), such as 1.0:0.1, 1.0:0.5, 1.0:1.0, 1.0:1.5, 1.0:2.0, 1.0:2.5, or 1.0:3.0, etc., but is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0046] The average particle size of the platinum-non-noble metal alloy is 2 nm to 4 nm, such as 2.0 nm, 2.3 nm, 2.5 nm, 2.8 nm, 3.0 nm, 3.2 nm, 3.5 nm, 3.8 nm, or 4.0 nm, etc., but is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0047] As a preferred technical solution of the present invention, based on the total mass of the carrier and the platinum-non-precious metal alloy being 100 wt%, the mass proportion of platinum is 30 wt% to 70 wt%, such as 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt% or 70 wt% etc., but not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0048] The molar ratio of the platinum to the non-precious metal is 1.0:(0.1~0.5), such as 1.0:0.1, 1.0:0.2, 1.0:0.3, 1.0:0.4 or 1.0:0.5 etc., but not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0049] In the third aspect, the present invention also provides an application of the oxygen reduction electrocatalyst as described in the second aspect in the field of hydrogen-oxygen fuel cells.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] (1) The preparation method provided by the present invention is not only applicable to the preparation of platinum-rare earth alloys, but also applicable to the preparation of platinum-transition metals, has a wide selectivity for carriers, does not require pre-treatment of the carriers, is simple, rapid, easy to control, has universality, and is suitable for mass production.

[0052] (2) By using a dispersant, the present invention can prepare catalysts with different platinum loadings, and the platinum loading can be as high as 80 wt%, and the nanoparticle sizes are uniform and the dispersibility is good.

[0053] (3) The oxygen reduction catalyst prepared by the present invention has efficient reaction kinetics and lasting stability, and its mass activity is more than 5 times that of commercial Pt / C, and the mass activity will not decrease after cycling 30,000 times at a low potential (0.6V~0.95V). BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 is a schematic flow chart of the preparation method provided in Example 1.

[0055] Figure 2 is a linear voltammogram of the catalyst prepared by the preparation method provided in Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0056] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations to the present invention.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs; the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "comprising" and "having" and any variations thereof in the specification and claims of this application and the above description of the drawings are intended to cover non-exclusive inclusion.

[0058] Example 1

[0059] This example provides a method for preparing an oxygen reduction electrocatalyst PtGd / C alloy with a Pt loading of 60 wt%, and the preparation process is as Figure 1 shown. First, the raw materials are dispersed evenly in a solvent, and then after drying, Joule heat treatment is carried out to obtain the oxygen reduction electrocatalyst, specifically as follows:

[0060] (1) Weigh 0.06 mmol of H2PtCl6, 0.02 mmol of GdCl2, 0.1 mmol of polyvinyl alcohol, and 7.8 mg of carbon support into a reaction vessel, and add 40 ml of deionized water thereto to form a metal ion precursor solution;

[0061] (2) Place the solution obtained in step (1) in an ultrasonic cleaner and ultrasonicate continuously for 25 min to obtain a uniformly dispersed solution, and then transfer it to a vacuum drying oven and dry it at 100 °C for 6 h to obtain a precursor material;

[0062] (3) Transfer the precursor material obtained in step (2) to a Joule heat device, keep it at 1000 °C for 30 s under nitrogen protection, and then take it out after cooling to room temperature under nitrogen protection to obtain a PtGd / C alloy catalyst with a Pt loading of 60 wt%.

[0063] Example 2

[0064] This example provides a method for preparing an oxygen reduction electrocatalyst PtLa / C alloy with a Pt loading of 70 wt%, which is prepared by the following steps:

[0065] (1) Weigh 0.06 mmol of H2PtCl6, 0.03 mmol of LaCl3, 0.12 mmol of ethyl acetate, and 5.0 mg of carbon support into a reaction vessel, and add 40 ml of deionized water thereto to form a metal ion precursor solution;

[0066] (2) Place the solution obtained in step (1) in an ultrasonic cleaner and ultrasonicate continuously for 30 min to obtain a uniformly dispersed solution, and then transfer it to a vacuum drying oven and dry it at 80 °C for 5 h to obtain a precursor material;

[0067] (3) Transfer the precursor material obtained in step (2) to a joule heating device. Under nitrogen protection, keep it at 1200 °C for 20 s, then cool it to room temperature under nitrogen protection and take it out to obtain a PtLa / C alloy catalyst with a Pt loading of 70 wt%.

[0068] Example 3

[0069] This example provides a method for preparing an oxygen reduction electrocatalyst PtFe / C alloy with a Pt loading of 30 wt%, which is prepared by the following steps:

[0070] (1) Weigh 0.06 mmol of H2PtCl6, 0.006 mmol of FeCl3, 0.03 mmol of polyvinylpyrrolidone and 27.3 mg of carbon support into a reaction vessel, and add 40 ml of deionized water thereto to form a metal ion precursor solution;

[0071] (2) Place the solution obtained in step (1) in an ultrasonic cleaner and ultrasonicate it continuously for 20 min to obtain a uniformly dispersed solution, and then transfer it to a vacuum drying oven and dry it at 60 °C for 7 h to obtain a precursor material;

[0072] (3) Transfer the precursor material obtained in step (2) to a joule heating device. Under nitrogen protection, keep it at 700 °C for 90 s, then cool it to room temperature under nitrogen protection and take it out to obtain a PtFe / C alloy catalyst with a Pt loading of 30 wt%.

[0073] Example 4

[0074] The difference between this example and Example 1 is that in this example, 0.3 mmol of polyvinyl alcohol is added;

[0075] The remaining preparation methods and parameters are the same as those in Example 1.

[0076] Example 5

[0077] The difference between this example and Example 1 is that in this example, 0.018 mmol of polyvinyl alcohol is added;

[0078] The remaining preparation methods and parameters are the same as those in Example 1.

[0079] Example 6

[0080] The difference between this example and Example 1 is that in this example, 0.18 mmol of polyvinyl alcohol is added;

[0081] The remaining preparation methods and parameters are the same as those in Example 1.

[0082] Example 7

[0083] The difference between this embodiment and Embodiment 1 is that in this embodiment, 0.62 mg of carbon support is added;

[0084] The remaining preparation methods and parameters are the same as those in Embodiment 1.

[0085] Embodiment 8

[0086] The difference between this embodiment and Embodiment 1 is that in this embodiment, 46.8 mg of carbon support is added;

[0087] The remaining preparation methods and parameters are the same as those in Embodiment 1.

[0088] Embodiment 9

[0089] The difference between this embodiment and Embodiment 1 is that in this embodiment, 2.9 mg of carbon support is added;

[0090] The remaining preparation methods and parameters are the same as those in Embodiment 1.

[0091] Embodiment 10

[0092] The difference between this embodiment and Embodiment 1 is that in this embodiment, the temperature of Joule heat is 3000 °C;

[0093] The remaining preparation methods and parameters are the same as those in Embodiment 1.

[0094] Embodiment 11

[0095] The difference between this embodiment and Embodiment 1 is that in this embodiment, the temperature of Joule heat is 300 °C;

[0096] The remaining preparation methods and parameters are the same as those in Embodiment 1.

[0097] Embodiment 12

[0098] The difference between this embodiment and Embodiment 1 is that in this embodiment, the temperature of Joule heat is 1300 °C;

[0099] The remaining preparation methods and parameters are the same as those in Embodiment 1.

[0100] Embodiment 13

[0101] The difference between this embodiment and Embodiment 1 is that in this embodiment, the drying temperature is 120 °C;

[0102] The remaining preparation methods and parameters are the same as those in Embodiment 1.

[0103] Embodiment 14

[0104] The difference between this embodiment and Embodiment 1 is that in this embodiment, GdCl2 is replaced by DyCl2;

[0105] The remaining preparation methods and parameters are the same as those in Example 1.

[0106] Comparative Example 1

[0107] The difference between this comparative example and Example 1 is that in this comparative example, polyvinyl alcohol is not added;

[0108] The remaining preparation methods and parameters are the same as those in Example 1.

[0109] Comparative Example 2

[0110] The difference between this comparative example and Example 1 is that in this comparative example, GdCl2 is not added;

[0111] The remaining preparation methods and parameters are the same as those in Example 1.

[0112] Comparative Example 3

[0113] The difference between this comparative example and Example 1 is that in this comparative example, polyvinyl alcohol is replaced by sodium citrate;

[0114] The remaining preparation methods and parameters are the same as those in Example 1.

[0115] Performance Test

[0116] The oxygen reduction electrocatalysts prepared in Examples 1-14 and Comparative Examples 1-3 were tested by LSV. The test method parameters were set as follows: scanning voltage 0.05V~1.15V, scanning rate 5mV / s, rotation speed 1600rpm. Under the condition of oxygen passing, the mass of the oxygen reduction electrocatalyst dropped on the glassy carbon electrode head was 0.02mg, and the area was 0.196cm 2 . The test results are shown in Table 1 below and Figure 2 as follows.

[0117] Table 1

[0118]

[0119] From Figure 2 and the data of Examples 1-14 in Table 1, it can be seen that the preparation method of the present invention can realize the preparation of different platinum loadings and different types of platinum-non-noble metal alloys, and the prepared catalysts have high activity and stability. From the data comparison between Example 1 and Comparative Examples 1-3 in Table 1, it can be known that the addition of the dispersant and rare earth metal in the preparation process plays a crucial role. If the dispersant is not added, as shown in Comparative Examples 1 and 3, the performance of the catalyst drops significantly compared with the case where the dispersant is added in Example 1.

[0120] From the data comparison between Example 1 and Examples 4 - 6 in Table 1, it can be seen that the molar ratios of platinum in the platinum source, non - precious metals in the non - precious metal source, and the dispersant during the preparation process also have an impact on the performance of the catalyst. By controlling their molar ratios within 1.0:(0.1 - 3.0):(0.1 - 4.0), and further controlling within the range of 1.0:(0.1 - 0.5):(0.5 - 2.0), it is more conducive to improving the performance of the catalyst; from the data comparison between Example 1 and Examples 7 - 9 in Table 1, it can be seen that the higher the platinum loading is not necessarily better. When using the preparation method of the present invention, when the platinum loading is within 30wt% - 70wt%, it is more conducive to obtaining a catalyst with excellent performance.

[0121] From the data comparison between Example 1 and Examples 10 - 13, it can be seen that by controlling the temperature of Joule heat treatment within 500℃ - 2500℃, and further controlling within 700℃ - 1200℃, and controlling the drying temperature within the range of 60℃ - 100℃, the prepared catalyst can have higher mass activity; from the data comparison between Example 1 and Example 14, it can be seen that choosing Gd element as the rare earth metal can further improve the performance of the catalyst compared with Dy element.

[0122] The applicant declares that the above - mentioned is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by any person skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A preparation method of an oxygen reduction electrocatalyst, characterized in that, The preparation method includes: dispersing a platinum source, a non-noble metal source, a dispersant and a carrier in a solvent, drying to obtain a precursor material, and then subjecting the precursor material to Joule heat treatment to obtain the oxygen reduction electrocatalyst; The non-noble metal source is a rare earth metal source; The molar ratio of platinum in the platinum source, non-noble metal in the non-noble metal source and the dispersant is 1.0:(0.1~3.0):(0.1~4.0); The platinum source is any one or a combination of at least two of chloroplatinic acid, platinum chloride or organic platinum salt, the rare earth metal source is any one of GdCl2, LaCl3 or DyCl2, the dispersant is any one or a combination of at least two of polyvinyl alcohol, ethyl acetate, polyvinylpyrrolidone, cetyltrimethylammonium bromide or dodecyltrimethylammonium chloride, and the solvent is deionized water; The oxygen reduction electrocatalyst includes a carrier and a platinum-non-noble metal alloy supported on the carrier.

2. The preparation method of the oxygen reduction electrocatalyst according to claim 1, characterized in that The mass ratio of platinum in the platinum source to the carrier is (2~8):(2~8).

3. The preparation method of the oxygen reduction electrocatalyst according to claim 1, wherein, The molar ratio of platinum in the platinum source, non-noble metal in the non-noble metal source and the dispersant is 1.0:(0.1~0.5):(0.5~2.0); The mass ratio of platinum in the platinum source to the carrier is (3~7):(3~7).

4. The preparation method of the oxygen reduction electrocatalyst according to claim 1, characterized in that, The method of dispersion includes ultrasonic treatment; The time of ultrasonic treatment is 20 min to 30 min; The drying temperature is 60°C to 100°C; The drying time is 5 h to 7 h; The temperature of Joule heat treatment is 500°C to 2500°C; The time of Joule heat treatment is 5 s to 100 s; The atmosphere of Joule heat treatment is any one or a combination of at least two of argon, nitrogen, ammonia or hydrogen.

5. The preparation method of the oxygen reduction electrocatalyst according to claim 1, wherein, The temperature of Joule heat treatment is 700°C to 1200°C; The time of Joule heat treatment is 20 s to 90 s.

6. The preparation method of the oxygen reduction electrocatalyst according to claim 1, characterized in that, The preparation method includes the following steps: According to the molar ratio of platinum in the platinum source, non-noble metal in the non-noble metal source and the dispersant of 1.0:(0.1~0.5):(0.5~2.0), and the mass ratio of platinum in the platinum source to the carrier of (3~7):(3~7), disperse the platinum source, non-noble metal source, dispersant and carrier in a solvent, perform ultrasonic treatment for 20 min to 30 min, then dry at 60°C to 100°C for 5 h to 7 h to obtain a precursor material, and finally perform Joule heat treatment on the precursor material at 700°C to 1200°C for 20 s to 90 s to obtain the oxygen reduction electrocatalyst; The non-noble metal source is a rare earth metal source, and the rare earth metal source is any one of GdCl2, LaCl3 or DyCl2; The dispersant is any one or a combination of at least two of polyvinyl alcohol, ethyl acetate, polyvinylpyrrolidone, cetyltrimethylammonium bromide or dodecyltrimethylammonium chloride; The atmosphere of Joule heat treatment is any one or a combination of at least two of argon, nitrogen, ammonia or hydrogen.

7. An oxygen reduction electrocatalyst prepared by the preparation method of the oxygen reduction electrocatalyst according to any one of claims 1-6.

8. An oxygen reduction electrocatalyst prepared by the method for preparing an oxygen reduction electrocatalyst according to claim 1, characterized in that, The oxygen reduction electrocatalyst includes a carrier and a platinum-non-precious metal alloy supported on the carrier; Based on the total mass of the carrier and the platinum-non-precious metal alloy being 100 wt%, the mass proportion of platinum is 20 wt% to 80 wt%; The average particle size of the platinum-non-precious metal alloy is 2 nm to 4 nm.

9. The oxygen reduction electrocatalyst according to claim 8, characterized in that, Based on the total mass of the carrier and the platinum-non-precious metal alloy being 100 wt%, the mass proportion of platinum is 30 wt% to 70 wt%.

10. Use of an oxygen reduction electrocatalyst according to any one of claims 7-9 in the field of hydrogen-oxygen fuel cells.

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