Multicomponent platinum-bismuth-based intermetallic ordered nanosheets, and preparation method and application thereof

Abstract

The application provides a multi-component platinum-bismuth-based intermetallic ordered nanosheet and a preparation method and application thereof, and relates to the technical field of multi-metal alloy catalysts.The multi-component platinum-bismuth-based intermetallic ordered nanosheet provided by the application comprises platinum elements, bismuth elements and auxiliary metal elements, the auxiliary elements comprise 1-4 kinds of iridium elements, ruthenium elements, osmium elements, rhodium elements, tin elements and lead elements, and the multi-component platinum-bismuth-based intermetallic ordered nanosheet has an intermetallic ordered structure and a two-dimensional nanosheet morphology.The multi-component platinum-bismuth-based intermetallic ordered nanosheet provided by the application is structurally stable, is applied to a fuel cell as a catalyst, and has excellent electrocatalytic performance, including formic acid oxidation electrocatalytic performance and alcohol oxidation electrocatalytic performance.The application provides a preparation method of the multi-component platinum-bismuth-based intermetallic ordered nanosheet, the preparation conditions are mild and simple to operate, and problems such as catalyst agglomeration caused by high-temperature calcination to transform an ordered phase are effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of multi-metal alloy catalyst technology, and in particular to a multi-component platinum-bismuth-based intermetallic ordered nanosheet, its preparation method, and its application. Background Technology

[0002] Platinum-based multimetallic alloy catalysts are key catalytic materials for energy devices such as fuel cells. Modifying the composition of catalytic materials and regulating the electronic structure of metal atoms are effective strategies for optimizing the adsorption / desorption of reaction intermediates and improving catalytic performance. Forming alloys (PtM, M = Fe / Co / Ni / Cu) with other transition metals (Pt) not only adjusts the d-band center position of Pt and optimizes the binding energy between Pt and reaction intermediates, but also effectively reduces the loading of platinum. However, due to thermodynamic limitations, the M atoms in traditional alloys (PtM) have limited control over the electronic structure of platinum; the diffusion barrier of M atoms is low, resulting in poor durability. How to improve the catalytic activity and stability of traditional alloy nanomaterials has always been one of the core issues in the field of fuel cell catalytic reactions. Summary of the Invention

[0003] In view of this, the purpose of this invention is to provide a multi-component platinum-bismuth-based intermetallic ordered nanosheet, its preparation method, and its application. The multi-component platinum-bismuth-based intermetallic ordered nanosheet provided by this invention, when used as a catalyst in fuel cells, exhibits excellent electrocatalytic performance.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] This invention provides a multi-component platinum-bismuth-based intermetallic ordered nanosheet, comprising platinum, bismuth, and auxiliary metal elements. The auxiliary elements include 1 to 4 of iridium, ruthenium, osmium, rhodium, tin, and lead. The multi-component platinum-bismuth-based intermetallic ordered nanosheet has an intermetallic ordered structure and a two-dimensional nanosheet morphology.

[0006] Preferably, the molar percentage of each metal element in the multi-component platinum-bismuth-based intermetallic ordered nanosheet is independently 5-65%.

[0007] Preferably, the diameter of the multi-component platinum-bismuth-based intermetallic ordered nanosheets is 20–25 nm, and the thickness is 4–5 nm.

[0008] This invention provides a method for preparing multi-component platinum-bismuth-based intermetallic ordered nanosheets as described above, comprising the following steps:

[0009] A precursor dispersion is obtained by mixing a platinum source, a bismuth source, an auxiliary metal source, a reducing agent, a surfactant, and an organic solvent; the auxiliary metal source includes 1 to 4 of the following: iridium source, ruthenium source, osmium source, rhodium source, tin source, and lead source.

[0010] The precursor dispersion was heated to obtain a black colloidal dispersion;

[0011] The black colloidal dispersion was mixed with a cyclohexane-ethanol mixture and centrifuged. The resulting precipitate was washed to obtain the multi-component platinum-bismuth-based intermetallic ordered nanosheets.

[0012] Preferably, the platinum source includes one or more of platinum acetylacetonate, chloroplatinic acid, and potassium chloroplatinate; the bismuth source includes bismuth acetate and / or bismuth nitrate; the iridium source includes iridium acetylacetonate and / or iridium chloride; the ruthenium source includes one or more of ruthenium acetylacetonate, triruthenium dodecylcarbonyl, and ruthenium chloride; the osmium source includes triosmium dodecylcarbonyl and / or osmium chloride; the rhodium source includes rhodium acetylacetonate and / or rhodium chloride; the tin source includes tin acetylacetonate and / or tin chloride; and the lead source includes lead acetylacetonate and / or lead acetate.

[0013] Preferably, the reducing agent includes one or more of glucose, citric acid, and ascorbic acid; the surfactant includes one or more of quaternary ammonium salts, halide salts, and polyvinylpyrrolidone; and the organic solvent includes one or more of oleylamine, octadecene, ethylene glycol, and benzyl alcohol.

[0014] Preferably, the concentration of the platinum source in the precursor dispersion is 1-2 mg / mL, the concentration of the bismuth source is 0.5-2 mg / mL, the concentration of each auxiliary metal source is independently 0.5-2 mg / mL, the concentration of the reducing agent is 3-5 mg / mL, and the concentration of the surfactant is 3-5 mg / mL.

[0015] Preferably, the heating temperature is 180–230°C, and the holding time is 30–300 min.

[0016] This invention provides the application of multi-component platinum-bismuth-based intermetallic ordered nanosheets as described in the above technical solutions or the multi-component platinum-bismuth-based intermetallic ordered nanosheets prepared by the above technical solutions as catalysts in fuel cells.

[0017] Preferably, the application includes the catalytic oxidation of formic acid or alcohol, wherein the alcohol includes methanol and / or ethanol.

[0018] This invention provides a multi-component platinum-bismuth-based intermetallic ordered nanosheet, comprising platinum, bismuth, and auxiliary metal elements. The auxiliary elements include one to four elements selected from iridium, ruthenium, osmium, rhodium, tin, and lead. The multi-component platinum-bismuth-based intermetallic ordered nanosheet possesses an intermetallic ordered structure and a two-dimensional nanosheet morphology. The multi-component platinum-bismuth-based intermetallic ordered nanosheet provided by this invention not only possesses the high-activity site structure characteristics of two-dimensional nanosheets but also combines the unique electronic structure regulation advantages of intermetallic ordered structures, enabling this series of catalysts to exhibit excellent electrocatalytic performance, including formic acid oxidation electrocatalytic performance and methanol and ethanol oxidation electrocatalytic performance.

[0019] This invention provides a method for preparing multi-component platinum-bismuth-based intermetallic ordered nanosheets as described above. This invention adopts a wet chemical organic phase preparation method, which has mild preparation conditions and simple operation, and effectively avoids problems such as catalyst agglomeration caused by high-temperature calcination to transform into an ordered phase. Attached Figure Description

[0020] Figure 1 Transmission electron microscopy image of the hexa-membered high-entropy platinum-bismuth-based intermetallic ordered nanosheets prepared in Example 4;

[0021] Figure 2 Transmission electron microscopy image of the hexa-membered high-entropy platinum-bismuth-based intermetallic ordered nanosheets prepared in Example 4;

[0022] Figure 3 The X-ray diffraction pattern of the hexa-membered high-entropy platinum-bismuth-based intermetallic ordered nanosheets prepared in Example 4;

[0023] Figure 4 The formic acid oxidation activity comparison diagrams are shown for the series of multi-component platinum-bismuth-based intermetallic ordered nanosheets prepared in Examples 1-4 and commercial Pt / C catalysts under acidic conditions.

[0024] Figure 5 This is a comparison of the formic acid oxidation stability of the hexa-membered high-entropy platinum-bismuth-based intermetallic ordered nanosheets prepared in Example 4 and the commercial Pt / C catalyst under acidic conditions.

[0025] Figure 6 The graph shows a comparison of the methanol oxidation activities of the series of multi-component platinum-bismuth-based intermetallic ordered nanosheets prepared in Examples 1-4 and commercial Pt / C catalysts under acidic conditions.

[0026] Figure 7 This is a comparison of the methanol oxidation stability performance of the hexa-membered high-entropy platinum-bismuth-based intermetallic ordered nanosheets prepared in Example 4 and the commercial Pt / C catalyst under acidic conditions. Detailed Implementation

[0027] This invention provides a multi-component platinum-bismuth-based intermetallic ordered nanosheet, comprising platinum, bismuth, and auxiliary metal elements. The auxiliary elements include 1 to 4 of iridium, ruthenium, osmium, rhodium, tin, and lead. The multi-component platinum-bismuth-based intermetallic ordered nanosheet has an intermetallic ordered structure and a two-dimensional nanosheet morphology.

[0028] In this invention, when the auxiliary element includes one of iridium, ruthenium, osmium, rhodium, tin, and lead, the multi-component platinum-bismuth-based intermetallic ordered nanosheet is a ternary low-entropy platinum-bismuth-based intermetallic ordered nanosheet. In an embodiment of this invention, the ternary low-entropy platinum-bismuth-based intermetallic ordered nanosheet is a platinum-bismuth-iridium intermetallic ordered nanosheet. In this invention, when the auxiliary element includes two of iridium, ruthenium, osmium, rhodium, tin, and lead, the multi-component platinum-bismuth-based intermetallic ordered nanosheet is a quaternary medium-entropy platinum-bismuth-based intermetallic ordered nanosheet. In an embodiment of this invention, the quaternary medium-entropy platinum-bismuth-based intermetallic ordered nanosheet is a platinum-bismuth-iridium-rhodium intermetallic ordered nanosheet. In this invention, when the auxiliary element includes three of the elements iridium, ruthenium, osmium, rhodium, tin, and lead, the multi-component platinum-bismuth-based intermetallic ordered nanosheets are pentagonal high-entropy platinum-bismuth-based intermetallic ordered nanosheets. In this embodiment, the pentagonal high-entropy platinum-bismuth-based intermetallic ordered nanosheets are platinum-bismuth-iridium-rhodium-osmium intermetallic ordered nanosheets. In this invention, when the auxiliary element includes four of the elements iridium, ruthenium, osmium, rhodium, tin, and lead, the multi-component platinum-bismuth-based intermetallic ordered nanosheets are hexaagonal high-entropy platinum-bismuth-based intermetallic ordered nanosheets. In this embodiment, the hexaagonal high-entropy platinum-bismuth-based intermetallic ordered nanosheets are platinum-bismuth-iridium-rhodium-osmium-ruthenium intermetallic ordered nanosheets. In this invention, the molar percentage of each metal element in the multi-component platinum-bismuth-based intermetallic ordered nanosheets is preferably independently 5-65%, more preferably independently 9-42%.

[0029] In this invention, the multi-component platinum-bismuth-based intermetallic ordered nanosheets have an intermetallic ordered structure and a two-dimensional nanosheet morphology (nanosheet thickness is in the nanometer size). The diameter of the multi-component platinum-bismuth-based intermetallic ordered nanosheets is preferably 20-25 nm, and the thickness is preferably 4-5 nm.

[0030] This invention constructs a multi-metal intermetallic ordered nanosheet material, which has high activity and high stability.

[0031] This invention provides a method for preparing multi-component platinum-bismuth-based intermetallic ordered nanosheets as described above, comprising the following steps:

[0032] A precursor dispersion is obtained by mixing a platinum source, a bismuth source, an auxiliary metal source, a reducing agent, a surfactant, and an organic solvent; the auxiliary metal source includes 1 to 4 of the following: iridium source, ruthenium source, osmium source, rhodium source, tin source, and lead source.

[0033] The precursor dispersion was heated to obtain a black colloidal dispersion;

[0034] The black colloidal dispersion was mixed with a cyclohexane-ethanol mixture and centrifuged. The resulting precipitate was washed to obtain the multi-component platinum-bismuth-based intermetallic ordered nanosheets.

[0035] Unless otherwise specified, all raw materials involved in this invention are commercially available products well known in the art.

[0036] The present invention mixes a platinum source, a bismuth source, an auxiliary metal source, a reducing agent, a surfactant, and an organic solvent to obtain a precursor dispersion; the auxiliary metal source includes 1 to 4 of the following: iridium source, ruthenium source, osmium source, rhodium source, tin source, and lead source.

[0037] In this invention, the platinum source preferably includes one or more of platinum acetylacetonate, chloroplatinic acid, and potassium chloroplatinate; the bismuth source preferably includes bismuth acetate and / or bismuth nitrate; the iridium source preferably includes iridium acetylacetonate and / or iridium chloride; the ruthenium source preferably includes ruthenium acetylacetonate, ruthenium dodecylcarbonyl, and ruthenium chloride; the osmium source preferably includes osmium dodecylcarbonyl and / or osmium chloride; the rhodium source preferably includes rhodium acetylacetonate and / or rhodium chloride; the tin source preferably includes tin acetylacetonate and / or tin chloride; and the lead source preferably includes lead acetylacetonate and / or lead acetate. In this invention, the reducing agent preferably includes one or more of glucose, citric acid, and ascorbic acid; the surfactant preferably includes one or more of quaternary ammonium salts, halide salts (i.e., salts containing halide ions) and polyvinylpyrrolidone (PVP), wherein the quaternary ammonium salt is preferably hexadecyltrimethylammonium chloride, and the halide salt is preferably ammonium bromide; the organic solvent preferably includes one or more of oleylamine, octadecene, ethylene glycol, and benzyl alcohol.

[0038] In this invention, the mixing method is preferably ultrasonic stirring, the ultrasonic power of which is preferably 50-100W, but can be 60, 70, 80 or 90W, and the time is preferably 30-90min, but can be 50, 60 or 70min. After ultrasonic stirring, a uniformly dispersed precursor dispersion is obtained, which is a turbid and uniform gel.

[0039] In this invention, the concentration of the platinum source in the precursor dispersion is preferably 1-2 mg / mL, which can be 1 or 2 mg / mL; the concentration of the bismuth source is preferably 0.5-2 mg / mL, which can be 0.5, 1, 1.5 or 2 mg / mL; the concentration of each auxiliary metal source is preferably 0.5-2 mg / mL independently, which can be 0.5, 1, 1.5 or 2 mg / mL; the concentration of the reducing agent is preferably 3-5 mg / mL, which can be 3, 3.5, 4, 4.5 or 5 mg / mL; and the concentration of the surfactant is preferably 3-5 mg / mL, which can be 3, 3.5, 4, 4.5 or 5 mg / mL.

[0040] After obtaining the precursor dispersion, the present invention heats the precursor dispersion to obtain a black colloidal dispersion. In the present invention, the heating temperature is preferably 180–230°C, more preferably 200–230°C, and even more preferably 220–230°C; the holding time is preferably 30–300 min, more preferably 60–180 min, and even more preferably 60–100 min; the heating is preferably oil bath heating, that is, the precursor dispersion is transferred to an oil bath for heating. During the heating process, chemical nucleation growth occurs to obtain a black colloidal dispersion containing two-dimensional intermetallic ordered nanosheets.

[0041] After obtaining the black colloidal dispersion, the present invention mixes the black colloidal dispersion with a cyclohexane-ethanol mixed solution and centrifuges the mixture, and washes the resulting precipitate to obtain the multi-component platinum-bismuth-based intermetallic ordered nanosheets.

[0042] In this invention, the preferred volume ratio of cyclohexane to ethanol in the cyclohexane-ethanol mixed solution is 2:1, and the preferred volume ratio of the black colloidal dispersion to the cyclohexane-ethanol mixed solution is 1-3:1-3, more preferably 5:3. In this invention, the cyclohexane-ethanol mixed solution serves to separate the precipitated products. Preferably, the black colloidal dispersion is cooled to room temperature before the cyclohexane-ethanol mixed solution is added. In this invention, the preferred centrifugation speed is 8000-9500 r / min, more preferably 9000 r / min, and the preferred centrifugation time is 3-5 min.

[0043] In this invention, the cleaning solution used is preferably a cyclohexane-ethanol mixed solution, wherein the volume ratio of cyclohexane to ethanol in the cyclohexane-ethanol mixed solution is preferably 1-3:1-3, more preferably 1:3; and the number of cleaning cycles is preferably 2-3.

[0044] In this embodiment of the invention, after obtaining the multi-component platinum-bismuth-based intermetallic ordered nanosheets, it is preferable to disperse the multi-component platinum-bismuth-based intermetallic ordered nanosheets in cyclohexane to prepare a standby solution.

[0045] Compared to disordered solid solution structures, ordered intermetallic structures not only allow for uniaxial strain modulation of surface electronic structures but also exhibit strong structural stability in strong acids. Furthermore, to enhance the application of catalytic materials in practical membrane electrodes, it is often necessary to design catalytic materials with ultra-high specific surface areas to improve surface transport impedance, which poses a new challenge to the number of active sites on the surface of traditional alloy materials. Among various platinum-based nanomaterials, two-dimensional platinum-based multimetallic materials have attracted attention due to their large specific surface area and strong contact with the support, making them highly promising for applications in various energy catalysis fields. However, the construction of two-dimensional platinum-based materials remains a significant challenge in the field of nanometal preparation due to both thermodynamic and kinetic limitations. This invention, by controlling the concentrations of metal precursors, surfactants, and reducing agents, as well as the reaction temperature and reaction time, can precisely regulate the reaction kinetics of the formation process of multi-component platinum-bismuth-based ordered intermetallic nanosheets. The reaction conditions are mild, and the microstructure of the resulting multi-component platinum-bismuth-based ordered intermetallic nanosheets is controllable, which is of great significance in the research of ordered intermetallic alloys. The preparation method provided by this invention is simple, feasible, and easy to scale up.

[0046] This invention provides the application of multi-component platinum-bismuth-based intermetallic ordered nanosheets, as described in the above technical solutions or prepared by the above methods, as catalysts in fuel cells. In this invention, the application preferably includes catalytic oxidation of formic acid or alcohol, wherein the alcohol preferably includes methanol and / or ethanol; the formic acid or alcohol oxidation is preferably carried out under acidic conditions. This invention does not impose any particular requirements on the method of application; methods well-known to those skilled in the art can be used.

[0047] To further illustrate the present invention, the following detailed description, in conjunction with examples, of the multi-component platinum-bismuth-based intermetallic ordered nanosheets, their preparation methods, and applications provided by the present invention, should not be construed as limiting the scope of protection of the present invention.

[0048] Example 1

[0049] The preparation steps of multi-component platinum-bismuth-based intermetallic ordered nanosheets (ternary low-entropy platinum-bismuth-based intermetallic ordered nanosheets) are as follows:

[0050] (1) Platinum acetylacetonate, bismuth acetate, iridium acetylacetonate, glucose and ammonium bromide were dissolved in oleylamine solvent at concentrations of 2 mg / mL, 1 mg / mL, 1.5 mg / mL, 3 mg / mL and 3 mg / mL, respectively, and sonicated (sonication power of 60W) for 60 min to obtain a turbid and uniform colloidal precursor dispersion.

[0051] (2) The precursor dispersion is transferred to an oil bath and heated in an oil bath. After the dispersion is heated to 230°C, it is kept at the temperature. After the dispersion reacts at this temperature for 60 minutes, a black gel-like dispersion is generated. Then the heating is stopped.

[0052] (3) After the reaction vessel is cooled to room temperature, 3 mL of cyclohexane-ethanol mixed solution (the volume ratio of cyclohexane to ethanol is 2:1) is added to 5 mL of the black colloidal dispersion. Then, the mixture is centrifuged at 9000 r / min for 5 min, and then washed twice with cyclohexane-ethanol mixed solution (the volume ratio of cyclohexane to ethanol is 1:3) to obtain ternary low-entropy platinum-bismuth-iridium intermetallic ordered nanosheets with a diameter of 20 nm and a thickness of 4 nm. The molar ratio of each metal element in the nanosheet is Pt:Bi:Ir=42:36:22.

[0053] Example 2

[0054] The preparation steps of multi-component platinum-bismuth-based intermetallic ordered nanosheets (quaternary medium-entropy platinum-bismuth-based intermetallic ordered nanosheets) are as follows:

[0055] (1) Platinum acetylacetone, bismuth acetate, iridium acetylacetone, rhodium acetylacetone, glucose and ammonium bromide were dissolved in oleylamine solvent at concentrations of 2 mg / mL, 1 mg / mL, 1.5 mg / mL, 1.5 mg / mL, 3 mg / mL and 3 mg / mL, respectively, and sonicated (sonication power of 70W) for 70 min to obtain a turbid and uniform colloidal precursor dispersion.

[0056] (2) The precursor dispersion is transferred to an oil bath and heated in an oil bath. After the dispersion is heated to 230°C, it is kept at the temperature. After the dispersion reacts at this temperature for 60 minutes, a black gel-like dispersion is generated. Then the heating is stopped.

[0057] (3) After the reaction vessel is cooled to room temperature, 3 mL of cyclohexane-ethanol mixed solution (the volume ratio of cyclohexane to ethanol is 2:1) is added to 5 mL of the black colloidal dispersion. Then, the mixture is centrifuged at 9000 r / min for 5 min and then washed twice with cyclohexane-ethanol mixed solution (the volume ratio of cyclohexane to ethanol is 1:3) to obtain quaternary medium-entropy platinum-bismuth-iridium-rhodium intermetallic ordered nanosheets with a diameter of 20 nm and a thickness of 4 nm. The molar ratio of each metal element in the nanosheet is Pt:Bi:Ir:Rh=32:35:15:18.

[0058] Example 3

[0059] The preparation steps of multi-component platinum-bismuth-based intermetallic ordered nanosheets (pentabyte high-entropy platinum-bismuth-based intermetallic ordered nanosheets) are as follows:

[0060] (1) Platinum acetylacetone, bismuth acetate, iridium acetylacetone, rhodium acetylacetone, triosmium dodecyl carbonyl, glucose and ammonium bromide were dissolved in oleylamine solvent at concentrations of 2 mg / mL, 1 mg / mL, 1.5 mg / mL, 1.5 mg / mL, 1.5 mg / mL, 5 mg / mL and 5 mg / mL, respectively, and sonicated (sonication power of 80W) for 70 min to obtain a turbid and uniform colloidal precursor dispersion.

[0061] (2) The precursor dispersion is transferred to an oil bath and heated in an oil bath. After the dispersion is heated to 230°C, it is kept at the temperature. After the dispersion reacts at this temperature for 60 minutes, a black gel-like dispersion is generated. Then the heating is stopped.

[0062] (3) After the reaction vessel is cooled to room temperature, 3 mL of cyclohexane-ethanol mixed solution (the volume ratio of cyclohexane to ethanol is 2:1) is added to 5 mL of the black colloidal dispersion. Then, the mixture is centrifuged at 9000 r / min for 5 min and then washed twice with cyclohexane-ethanol mixed solution (the volume ratio of cyclohexane to ethanol is 1:3) to obtain five-element high-entropy platinum-bismuth-iridium-rhodium-osmium intermetallic ordered nanosheets with a diameter of 20 nm and a thickness of 5 nm. The molar ratio of each metal element in the nanosheet is Pt:Bi:Ir:Rh:Os=28:30:13:16:13.

[0063] Example 4

[0064] The preparation steps of multi-component platinum-bismuth-based intermetallic ordered nanosheets (six-component high-entropy platinum-bismuth-based intermetallic ordered nanosheets) are as follows:

[0065] (1) Platinum acetylacetonate, bismuth acetate, iridium acetylacetonate, rhodium acetylacetonate, triosmium dodecyl carbonyl, ruthenium acetylacetonate, glucose and ammonium bromide were dissolved in oleylamine solvent at concentrations of 2 mg / mL, 1 mg / mL, 1.5 mg / mL, 1.5 mg / mL, 1.5 mg / mL, 1.5 mg / mL, 5 mg / mL and 5 mg / mL, respectively, and sonicated (ultrasonic power of 90W) for 70 min to obtain a turbid and uniform colloidal precursor dispersion.

[0066] (2) The precursor dispersion is transferred to an oil bath and heated in an oil bath. After the dispersion is heated to 230°C, it is kept at the temperature. After the dispersion reacts at this temperature for 60 minutes, a black gel-like dispersion is generated. Then the heating is stopped.

[0067] (3) After the reaction vessel is cooled to room temperature, 3 mL of cyclohexane-ethanol mixed solution (the volume ratio of cyclohexane to ethanol is 2:1) is added to 5 mL of the black colloidal dispersion. Then, the mixture is centrifuged at 9000 r / min for 5 min and then washed twice with cyclohexane-ethanol mixed solution (the volume ratio of cyclohexane to ethanol is 1:3) to obtain six-element high-entropy platinum-bismuth-iridium-rhodium-osmium-ruthenium intermetallic ordered nanosheets with a diameter of 20 nm and a thickness of 5 nm. The molar ratio of each metal element in the nanosheet is Pt:Bi:Ir:Rh:Os:Ru=20:31:14:15:11:9.

[0068] Figure 1 and Figure 2 The images show transmission electron microscopy (TEM) images at different scales of the hexa-membered high-entropy platinum-bismuth-based intermetallic ordered nanosheets prepared in Example 4. Figure 1 It can be seen that the diameter of the nanosheets is 20–25 nm; from Figure 2 It can be seen that the thickness of the nanosheets is 4–5 nm.

[0069] Figure 3 The X-ray diffraction pattern of the hexa-membered high-entropy platinum-bismuth-based intermetallic ordered nanosheets prepared in Example 4 shows that they have an ordered structure.

[0070] The electrocatalytic performance of the poly-component platinum-bismuth-based intermetallic ordered nanosheets prepared in the examples for formic acid oxidation was tested. The test methods and conditions were as follows: all electrochemical test data were collected by the Shanghai Chenhua workstation. A three-electrode system was used for the electrochemical formic acid oxidation performance test. The working electrode was a Pine disk electrode, the reference electrode was a saturated calomel electrode, and the counter electrode was a carbon rod. The formic acid oxidation electrolyte was a 0.1 M perchloric acid solution containing 0.5 M formic acid. The formic acid oxidation potential window was 0.1–1.1 V (vs. RHE), and the scan rate was 50 mV / s. -1 Stability testing was performed using IT technology at 0.4V for 5000s, with a commercial platinum-carbon (Pt / C) catalyst as a control. Figure 4 This is a comparison of the formic acid oxidation activities of the series of multi-component platinum-bismuth-based intermetallic ordered nanosheets prepared in Examples 1-4 and commercial Pt / C catalysts under acidic conditions. Figure 4 The ternary low-entropy, quaternary medium-entropy, pentagonal high-entropy, and hexagram high-entropy intermetallic ordered nanosheet catalysts correspond to Examples 1, 2, 3, and 4, respectively. Figure 4 It can be seen that the multi-component platinum-bismuth-based intermetallic ordered nanosheet catalysts exhibit superior formic acid oxidation performance. Among them, the hexa-component high-entropy platinum-bismuth-based intermetallic ordered nanosheets show the best performance, with the reaction following a dehydrogenation pathway. At 0.75V, its formic acid oxidation mass activity is 12.4 Amg. Pt -1 It is about 62 times higher than commercial Pt / C. Figure 5This is a comparison of the formic acid oxidation stability performance of the hexa-membered high-entropy platinum-bismuth-based intermetallic ordered nanosheets prepared in Example 4 and a commercial platinum-carbon catalyst under acidic conditions. Figure 5 As can be seen from the 5000s stability test results, the mass activity of the hexa-membered high-entropy intermetallic ordered nanosheets is much higher than that of commercial platinum-carbon catalysts.

[0071] The electrocatalytic performance of methanol oxidation of the multi-component platinum-bismuth-based intermetallic ordered nanosheets prepared in the examples was tested. The test methods and conditions were as follows: all electrochemical test data were collected by the Shanghai Chenhua workstation. A three-electrode system was used for the electrochemical methanol oxidation performance test. The working electrode was a Pine disk electrode, the reference electrode was a saturated calomel electrode, and the counter electrode was a carbon rod. The methanol oxidation electrolyte was a 0.1M perchloric acid solution containing 0.5M methanol. The methanol oxidation potential window was 0.1–1.1 V (vs. RHE), and the scan rate was 50 mV / s. -1 Stability testing was performed using IT technology at 0.9V for 5000s, with a commercial platinum-carbon (Pt / C) catalyst as a control. Figure 6 This is a comparison of the methanol oxidation activities of the series of multi-component platinum-bismuth-based intermetallic ordered nanosheets prepared in Examples 1-4 and the commercial Pt / C catalyst under acidic conditions. Figure 6 It can be seen that the multi-component platinum-bismuth-based intermetallic ordered nanosheet catalysts exhibit superior methanol oxidation performance. Among them, the hexa-component high-entropy platinum-bismuth-based intermetallic ordered nanosheets show the best performance, with a methanol oxidation mass activity of 5.2 Amg at 0.9 V. Pt -1 It is about 5 times higher than commercial Pt / C. Figure 7 This is a comparison of the stability of the hexa-membered high-entropy platinum-bismuth-based intermetallic ordered nanosheets prepared in Example 4 with that of a commercial platinum-carbon catalyst under acidic conditions during methanol oxidation. Figure 7 As can be seen from the 5000s stability test results, the mass activity of the hexa-membered high-entropy intermetallic ordered nanosheets is much higher than that of commercial platinum-carbon catalysts.

[0072] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A multi-component platinum-bismuth-based intermetallic ordered nanosheet, characterized in that, Composed of platinum, bismuth, and auxiliary metal elements, the auxiliary metal elements being iridium, ruthenium, osmium, and rhodium, the multi-component platinum-bismuth-based intermetallic ordered nanosheets possess an intermetallic ordered structure and a two-dimensional nanosheet morphology. The diameter of the multi-component platinum-bismuth-based intermetallic ordered nanosheets is 20-25 nm, and the thickness is 4-5 nm. The molar ratio of each metal element in the nanosheets is Pt:Bi:Ir:Rh:Os:Ru = 20:31:14:15:11:

9.

2. The method for preparing the multi-component platinum-bismuth-based intermetallic ordered nanosheets according to claim 1, characterized in that, Includes the following steps: A precursor dispersion is obtained by mixing a platinum source, a bismuth source, an auxiliary metal source, a reducing agent, a surfactant, and an organic solvent; the auxiliary metal source includes an iridium source, a ruthenium source, an osmium source, and a rhodium source. The precursor dispersion was heated to obtain a black colloidal dispersion; The black colloidal dispersion was mixed with a cyclohexane-ethanol mixture and centrifuged. The resulting precipitate was washed to obtain the multi-component platinum-bismuth-based intermetallic ordered nanosheets.

3. The preparation method according to claim 2, characterized in that, The platinum source includes one or more of platinum acetylacetonate, chloroplatinic acid, and potassium chloroplatinate; the bismuth source includes bismuth acetate and / or bismuth nitrate; the iridium source includes iridium acetylacetonate and / or iridium chloride; the ruthenium source includes one or more of ruthenium acetylacetonate, ruthenium dodecylcarbonyltriruthenium, and ruthenium chloride; the osmium source includes osmium dodecylcarbonyltriruthenium and / or osmium chloride; and the rhodium source includes rhodium acetylacetonate and / or rhodium chloride.

4. The preparation method according to claim 2, characterized in that, The reducing agent includes one or more of glucose, citric acid, and ascorbic acid; the surfactant includes one or more of quaternary ammonium salts, halide salts, and polyvinylpyrrolidone; and the organic solvent includes one or more of oleylamine, octadecene, ethylene glycol, and benzyl alcohol.

5. The preparation method according to claim 2, 3 or 4, characterized in that, The concentration of platinum source in the precursor dispersion is 1~2 mg / mL, the concentration of bismuth source is 0.5~2 mg / mL, the concentration of each auxiliary metal source is independently 0.5~2 mg / mL, the concentration of reducing agent is 3~5 mg / mL, and the concentration of surfactant is 3~5 mg / mL.

6. The preparation method according to claim 2, characterized in that, The heating temperature is 180~230℃, and the holding time is 30~300min.

7. The application of the multi-component platinum-bismuth-based intermetallic ordered nanosheets of claim 1 or the multi-component platinum-bismuth-based intermetallic ordered nanosheets prepared by any one of claims 2 to 6 as catalysts in fuel cells.

8. The application according to claim 7, characterized in that, The applications include the catalytic oxidation of formic acid or alcohols, including methanol and / or ethanol.

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