Oxygen reduction electrocatalyst as well as preparation method and application thereof

Abstract

The invention belongs to the field of electrocatalysts, and provides an oxygen reduction electrocatalyst and a preparation method and application thereof. The preparation method comprises the following steps: dispersing a platinum source, a non-noble metal source, a dispersing agent 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. According to the preparation method provided by the invention, the oxygen reduction electrocatalyst with different platinum loading capacities can be obtained only by simply mixing the raw materials and the dispersing agent and performing Joule heat treatment, and the prepared catalyst has the advantages of good dispersity, uniform metal nanoparticle size, high reaction kinetics and lasting stability; the preparation method provided by the invention is simple, easy to control and suitable for mass production.

Description

Technical Field

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

[0002] Hydrogen-oxygen fuel cells have advantages such as high energy conversion rate and clean products, but the oxygen reduction (ORR) reaction kinetics at the cathode are slow, and platinum or platinum-based catalysts are needed to accelerate the reaction. However, the platinum-based catalysts currently used 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 abnormally negative alloy formation energy, which gives them 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 the two metals are very different and rare earths have a strong affinity for oxygen. The current methods for synthesizing platinum-rare earth alloys are relatively extreme, such as extremely strong reducing agents and high temperatures. These conditions lead to larger particle sizes, or uneven dispersion, and even uneven distribution of Pt and rare earth elements, and phase separation. In addition, these preparation methods are time-consuming and energy-consuming, such as long-term high-temperature calcination using a heating device, reduction with extremely strong and dangerous reducing agents, or high-temperature smelting, belt throwing and other technologies. More importantly, many existing methods can only prepare catalysts with low platinum loading, and high platinum loading will cause particles to agglomerate and grow. However, catalysts with low platinum loading will cause many problems during the use of fuel cells. Although there are also some methods for preparing high platinum loading, the methods are complicated and have poor universality, and cannot prepare high-load 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 hot topic of research. Although there is an existing technology for preparing platinum-based catalysts using Joule heat methods, the preparation method has poor universality and cannot prepare platinum-rare earth related catalysts. It has many restrictions on the reaction raw materials, and the stability problem of the catalyst has not been solved. For example, CN202410299244.8 discloses a high entropy alloy composite material and its Joule heat preparation method and application, but the method does not prepare a platinum-based catalyst, and the carbon carrier needs to be oxidized first; CN202010714990.0 discloses an intermetallic compound-carbon nanotube composite material and its preparation method and application, but the non-precious metal in the catalyst does not involve rare earth metals, the carrier is also limited to carbon nanotubes, and the stability data of the catalyst cannot be verified.

[0005] Therefore, how to develop a mild, controllable, and universal preparation method that can achieve 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] In view of the deficiencies in the prior art, the purpose of the present invention is to provide an oxygen reduction electrocatalyst and its preparation method and application. The preparation method provided by the present invention does not require pretreatment of the carrier, and only requires simple mixing and Joule heat treatment of the raw materials and dispersants to obtain oxygen reduction electrocatalysts with different platinum loadings, and the prepared catalyst has good dispersibility and uniform metal nanoparticle size, showing 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] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a method for preparing an oxygen reduction electrocatalyst, the preparation method comprising: dispersing a platinum source, a non-precious 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, a platinum source, a non-precious metal source, a dispersant and a carrier are dispersed in a solvent at the same time, and then the solution is dried and subjected to Joule heat treatment. Due to the addition of the dispersant, on the one hand, the platinum source and the non-precious metal source can be uniformly distributed on the carrier during the mixing process; on the other hand, the dispersant can be adsorbed on the surface of the platinum and non-precious 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 promote the transfer of electrons between the platinum and the non-precious metals, thereby making the reduction temperatures of the two closer in the Joule heat reaction, which is beneficial to obtaining a more uniform phase.

[0010] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the technical objectives 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, the non-precious metal in the non-precious metal source and the dispersant is 1.0:(0.1~3.0):(0.1~4.0), for example, 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 is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0012] The mass ratio of platinum in the platinum source to the carrier is (2~8):(2~8), for example 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 the numerical range are also applicable.

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

[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, the use of a gadolinium source and / or a lanthanum source is more conducive to the simultaneous reduction of rare earth metals and platinum, thereby being more conducive to obtaining a phase-homogeneous oxygen reduction electrocatalyst.

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

[0018] It should be noted that the two elements Y and Sc are both rare earth metals and transition metals. In order to make the present invention easier to understand, 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, the non-precious metal in the non-precious metal source and the dispersant is 1.0:(0.1~0.5):(0.5~2.0), for example, 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 the numerical range are also applicable.

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

[0021] The mass ratio of platinum in the platinum source to the carrier is (3~7):(3~7), for example 3:7, 4:6, 5:5, 6:4 or 7:3, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0022] In the present invention, by regulating the mass ratio of platinum in the platinum source and the carrier, 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 balancing the catalyst activity and cost.

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

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

[0025] The ultrasonic time is 20 min to 30 min, for example 20 min, 22 min, 24 min, 25 min, 27 min, 28 min or 30 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

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

[0027] The drying temperature is 60°C to 100°C, for example 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also 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. to 100° C., it can be ensured that platinum is not oxidized during the drying process, thereby avoiding affecting the catalytic activity of the catalyst.

[0029] The drying time is 5 h to 7 h, for example, 5.0 h, 5.5 h, 6.0 h, 6.5 h or 7.0 h, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0030] The temperature of the Joule heat treatment is 500°C~2500°C, for example 500°C, 700°C, 1000°C, 1200°C, 1500°C, 1800°C, 2000°C, 2200°C or 2500°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0031] The time of the Joule heat treatment is 0.1s~1800s, for example 0.1s, 1s, 2s, 3s, 4s, 5s, 100s, 500s, 1000s, 1500s or 1800s, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

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

[0033] As a preferred technical solution of the present invention, the temperature of the Joule heat treatment is 700°C~1200°C, for example, 700°C, 800°C, 900°C, 1000°C, 1100°C or 1200°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] In the present invention, different Joule heat treatment temperatures can be selected according to different doping amounts of platinum and non-precious metals. By controlling the temperature of the Joule heat treatment within the range of 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 a relatively ideal state, thereby promoting the synergistic effect between platinum and non-precious metals, and further improving the catalytic activity, selectivity and stability of the catalyst.

[0035] The time of the Joule heat treatment is 20s to 90s, for example 20s, 30s, 40s, 50s, 60s, 70s, 80s or 90s, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

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

[0037] According to the molar ratio of platinum in the platinum source, the non-precious metal in the non-precious 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), the platinum source, the non-precious metal source, the dispersant and the carrier are dispersed in a solvent, ultrasonicated for 20 min-30 min, and then dried at 60° C.-100° C. for 5 h-7 h to obtain a precursor material, and finally the precursor material is subjected to Joule heat treatment at 700° C.-1200° C. for 20 s-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 of polyvinyl alcohol, ethyl acetate, polyvinyl pyrrolidone, hexadecyltrimethylammonium bromide or dodecyltrimethylammonium chloride, or a combination of at least two thereof;

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

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

[0042] The catalyst prepared by the preparation method of the present invention has metal particles with a small average particle size and uniform size, 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-precious metal alloy supported on the carrier.

[0044] Taking the total mass of the carrier and the platinum-non-precious metal alloy as 100wt%, the mass of the platinum accounts for 20wt% to 80wt%, for example, 20wt%, 30wt%, 40wt%, 50wt%, 60wt%, 70wt% or 80wt%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0045] The molar ratio of platinum to non-precious metal is 1.0:(0.1~3.0), for example 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 the numerical range are also applicable.

[0046] The average particle size of the platinum-non-precious metal alloy is 2nm~4nm, for example 2.0nm, 2.3nm, 2.5nm, 2.8nm, 3.0nm, 3.2nm, 3.5nm, 3.8nm or 4.0nm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

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

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

[0049] In a third aspect, the present invention further provides an application of the oxygen reduction electrocatalyst as described in the second aspect in the field of hydrogen and 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, and has a wide selectivity for the carrier, and does not require pretreatment of the carrier. The method is simple, rapid, easy to control, universal, and suitable for mass production.

[0052] (2) The present invention utilizes a dispersant to prepare catalysts with different platinum loadings. The platinum loading can be as high as 80 wt %, and the nanoparticles have uniform size and good dispersibility.

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

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

[0055] Figure 2 This is a linear voltammetric curve of the catalyst prepared by the preparation method provided in Example 1. DETAILED DESCRIPTION

[0056] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

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

[0058] Example 1

[0059] This embodiment provides a method for preparing an oxygen reduction electrocatalyst PtGd / C alloy, wherein the loading amount of Pt is 60wt%, and the preparation process is as follows: Figure 1 As shown, the raw materials are first dispersed uniformly in a solvent, and then subjected to Joule heat treatment after drying to obtain the oxygen reduction electrocatalyst, 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 container, and add 40 ml of deionized water to form a metal ion precursor solution;

[0061] (2) placing the solution obtained in step (1) in an ultrasonic cleaning machine and continuously ultrasonicating for 25 minutes to obtain a uniformly dispersed solution, and then transferring it to a vacuum drying oven and drying it at 100° C. for 6 hours to obtain a precursor material;

[0062] (3) The precursor material obtained in step (2) was transferred to a Joule heating device, and kept at 1000° C. for 30 seconds under nitrogen protection. The temperature was then lowered to room temperature under nitrogen protection and taken out to obtain a PtGd / C alloy catalyst with a Pt loading of 60 wt%.

[0063] Example 2

[0064] This embodiment provides a method for preparing an oxygen reduction electrocatalyst PtLa / C alloy, wherein the Pt loading is 70 wt %, and the preparation is performed 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 container, and add 40 ml of deionized water to form a metal ion precursor solution;

[0066] (2) placing the solution obtained in step (1) in an ultrasonic cleaning machine and continuously ultrasonicating for 30 minutes to obtain a uniformly dispersed solution, and then transferring it to a vacuum drying oven and drying it at 80° C. for 5 hours to obtain a precursor material;

[0067] (3) The precursor material obtained in step (2) was transferred to a Joule heating device, and kept at 1200° C. for 20 seconds under nitrogen protection. The temperature was then lowered to room temperature under nitrogen protection and taken out to obtain a PtLa / C alloy catalyst with a Pt loading of 70 wt%.

[0068] Example 3

[0069] This embodiment provides a method for preparing an oxygen reduction electrocatalyst PtFe / C alloy, wherein the Pt loading is 30 wt %, and the preparation is performed by the following steps:

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

[0071] (2) placing the solution obtained in step (1) in an ultrasonic cleaning machine and continuously ultrasonicating for 20 minutes to obtain a uniformly dispersed solution, and then transferring it to a vacuum drying oven and drying it at 60° C. for 7 hours to obtain a precursor material;

[0072] (3) The precursor material obtained in step (2) was transferred to a Joule heating device, kept at 700°C for 90 seconds under nitrogen protection, and then taken out after cooling to room temperature under nitrogen protection to obtain a PtFe / C alloy catalyst with a Pt loading of 30 wt%.

[0073] Example 4

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

[0075] The rest of the preparation methods and parameters were the same as those in Example 1.

[0076] Example 5

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

[0078] The rest of the preparation methods and parameters were the same as those in Example 1.

[0079] Example 6

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

[0081] The rest of the preparation methods and parameters were 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 carrier is added;

[0084] The rest of the preparation methods and parameters were the same as those in Example 1.

[0085] Example 8

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

[0087] The rest of the preparation methods and parameters were the same as those in Example 1.

[0088] Example 9

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

[0090] The rest of the preparation methods and parameters were the same as those in Example 1.

[0091] Example 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 rest of the preparation methods and parameters were the same as those in Example 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 rest of the preparation methods and parameters were the same as those in Example 1.

[0097] Example 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 rest of the preparation methods and parameters were the same as those in Example 1.

[0100] Example 13

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

[0102] The rest of the preparation methods and parameters were the same as those in Example 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 rest of the preparation methods and parameters were 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 rest of the preparation methods and parameters were 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 rest of the preparation methods and parameters were 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 rest of the preparation methods and parameters were the same as those in Example 1.

[0115] Performance Testing

[0116] The oxygen reduction electrocatalysts prepared in Examples 1-14 and Comparative Examples 1-3 were subjected to LSV tests. The test method parameters were set as follows: scanning voltage 0.05 V to 1.15 V, scanning rate 5 mV / s, rotation speed 1600 rpm, and under oxygen flow conditions, the mass of the oxygen reduction electrocatalyst added to the glassy carbon electrode tip was 0.02 mg, and the area was 0.196 cm 2 The test results are shown in Table 1 and Figure 2 shown.

[0117] Table 1

[0118]

[0119] Depend on Figure 2 As can be seen from the data of Examples 1-14 in Table 1, the preparation method of the present invention can achieve the preparation of different platinum loadings and different types of platinum-non-precious metal alloys, and the prepared catalyst has high activity and stability. From the comparison of the data of Example 1 and Comparative Examples 1-3 in Table 1, it can be seen that the addition of dispersants and rare earth metals in the preparation process plays a crucial role. If no dispersant is added, as shown in Comparative Examples 1 and Comparative Examples 3, the performance of the catalyst is greatly reduced compared to the case where a 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 ratio of platinum in the platinum source, the non-precious metal in the non-precious metal source and the dispersant during the preparation process will also affect the performance of the catalyst. By controlling the molar ratio within the range of 1.0:(0.1~3.0):(0.1~4.0), and further 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, the better. When the preparation method of the present invention is adopted, when the platinum loading is 30wt%~70wt%, it is more conducive to obtaining a catalyst with excellent performance.

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

[0122] The applicant declares that the above is only a specific implementation mode 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 those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing an oxygen reduction electrocatalyst, characterized in that: The preparation method comprises: dispersing a platinum source, a non-precious 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.

2. The method for preparing an oxygen reduction electrocatalyst according to claim 1, characterized in that: The molar ratio of platinum in the platinum source, the non-precious metal in the non-precious metal source and the dispersant is 1.0:(0.1-3.0):(0.1-4.0); The mass ratio of platinum in the platinum source to the carrier is (1-8):(2-9); The dispersant includes any one of polyvinyl alcohol, ethyl acetate, polyvinyl pyrrolidone, hexadecyltrimethylammonium bromide or dodecyltrimethylammonium chloride, or a combination of at least two thereof; The non-noble metal source includes a rare earth metal source and / or a transition metal source; The rare earth metal source includes a gadolinium source and / or a lanthanum source; The transition metal source includes any one of an iron source, a cobalt source or a nickel source, or a combination of at least two of them.

3. The method for preparing an oxygen reduction electrocatalyst according to claim 1, characterized in that: The molar ratio of platinum in the platinum source, the non-precious metal in the non-precious 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 method for preparing an oxygen reduction electrocatalyst according to claim 1, characterized in that: The dispersion method includes ultrasound; The ultrasound time is 20min~30min; The drying temperature is 60°C to 100°C; The drying time is 5h~7h; The temperature of the Joule heat treatment is 500°C to 2500°C; The Joule heat treatment time is 0.1s~1800s; The atmosphere of the Joule heat treatment is any one of argon, nitrogen, ammonia or hydrogen, or a combination of at least two of them.

5. The method for preparing an oxygen reduction electrocatalyst according to claim 1, characterized in that: The temperature of the Joule heat treatment is 700°C to 1200°C; The Joule heat treatment time is 20s to 90s.

6. The method for preparing an oxygen reduction electrocatalyst according to claim 1, characterized in that: The preparation method comprises the following steps: According to the molar ratio of platinum in the platinum source, the non-precious metal in the non-precious 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), the platinum source, the non-precious metal source, the dispersant and the carrier are dispersed in a solvent, ultrasonicated for 20 min-30 min, and then dried at 60° C.-100° C. for 5 h-7 h to obtain a precursor material, and finally the precursor material is subjected to Joule heat treatment at 700° C.-1200° C. for 20 s-90 s to obtain the oxygen reduction electrocatalyst; 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; The dispersant includes any one of polyvinyl alcohol, ethyl acetate, polyvinyl pyrrolidone, hexadecyltrimethylammonium bromide or dodecyltrimethylammonium chloride, or a combination of at least two thereof; The atmosphere of the Joule heat treatment is any one of argon, nitrogen, ammonia or hydrogen, or a combination of at least two of them.

7. An oxygen reduction electrocatalyst prepared by the method for preparing an oxygen reduction electrocatalyst according to any one of claims 1 to 6.

8. The oxygen reduction electrocatalyst according to claim 7, characterized in that The oxygen reduction electrocatalyst includes a carrier and a platinum-non-precious metal alloy supported on the carrier; Taking the total mass of the carrier and the platinum-non-precious metal alloy as 100wt%, the mass of the platinum accounts for 10wt% to 80wt%; The molar ratio of platinum to non-precious metal is 1.0:(0.1-3.0); The average particle size of the platinum-non-precious metal alloy is 2nm~4nm.

9. The oxygen reduction electrocatalyst according to claim 8, characterized in that Taking the total mass of the carrier and the platinum-non-precious metal alloy as 100wt%, the mass of the platinum accounts for 30wt% to 70wt%; The molar ratio of platinum to non-precious metal is 1.0:(0.1-0.5).

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

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