Tin dioxide loaded binary noble metal nanoparticle electrocatalyst as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of hydroxidation reaction electrocatalysts, and particularly relates to a tin dioxide loaded binary noble metal nanoparticle electrocatalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: adding a tin source and a sulfur source into an alcohol-water mixed solution, and carrying out hydrothermal reaction to prepare tin disulfide; carrying out heat treatment on the tin disulfide to obtain tin dioxide; the preparation method comprises the following steps: adding tin dioxide and a noble metal source into an alcohol solution containing a surfactant, and carrying out a heating reaction to obtain the tin dioxide loaded binary noble metal nanoparticle electrocatalyst. The tin dioxide carrier in the electrocatalyst effectively regulates and controls the electronic structure of the binary noble metal nanoparticles, and improves the hydrogen oxidation reaction activity of the metal nanoparticles. Meanwhile, the structural stability of the composite electrocatalyst is obviously improved due to the strong anchoring effect of the carrier on the binary metal nanoparticles. In addition, by means of the characteristics of high corrosion resistance and oxidation resistance of the tin dioxide carrier, high electrocatalytic activity and good durability are guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of electrocatalyst technology for hydroxide reaction, specifically relating to a tin dioxide-supported binary noble metal nanoparticle electrocatalyst, its preparation method, and its application. Background Technology

[0002] The continued consumption of traditional fossil fuels has triggered an increasingly severe energy crisis and environmental problems, driving the energy system towards a "cleaner, lower-carbon, safer, and more efficient" transformation. While renewable energy sources such as solar and wind power have the significant advantages of being clean and renewable, their inherent intermittency and volatility severely restrict large-scale, stable, and reliable grid connection and utilization. Developing efficient energy storage and conversion technologies is a key support for achieving effective renewable energy absorption and promoting the development of the new energy industry.

[0003] Hydrogen fuel cells, as efficient and zero-emission energy conversion devices, can directly convert the chemical energy of hydrogen fuel and oxidant into electrical energy, making them an important component of future clean energy systems. Among them, anion exchange membrane fuel cells (AEMFCs) exhibit significant cost advantages and application prospects due to their ability to operate under alkaline conditions and relatively lower requirements for catalyst materials. However, the anode and cathode reactions of AEMFCs still heavily rely on commercially available carbon black-supported platinum group metal catalysts. In alkaline media, the kinetic rate of the hydrogen oxidation reaction (HOR) of these commercial catalysts is about two orders of magnitude slower than in acidic media, resulting in a persistently high platinum group metal catalyst loading at the anode, severely restricting cost control and power density improvement. Furthermore, under actual operating conditions, the anode catalyst is prone to dissolution, migration, and Ostwald ripening of platinum group metal nanoparticles, leading to active particle aggregation and deactivation. In addition, traditional carbon supports are thermodynamically unstable at high potentials and are prone to electrochemical corrosion. Furthermore, the interfacial interaction between carbon supports and metal particles is weak, making it difficult to effectively anchor metal particles. This further exacerbates the loss of active components and the destruction of catalyst structure, resulting in a sharp decrease in electrochemical active area and severely impairing battery durability. Summary of the Invention

[0004] The purpose of this invention is to provide a tin dioxide-supported binary noble metal nanoparticle electrocatalyst, its preparation method, and its application. The catalyst comprises a tin dioxide support and a binary noble metal active component supported thereon. Using this electrocatalyst as an anode catalyst can improve the catalytic activity and structural stability of the noble metal nanoparticles. Furthermore, the choice of tin dioxide support overcomes the problem of dissolution due to thermodynamic instability under high voltage found in traditional carbon supports, thus improving durability.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: In a first aspect, the present invention provides a method for preparing a tin dioxide-supported binary noble metal nanoparticle electrocatalyst, comprising the following steps: Tin disulfide is prepared by adding a tin source and a sulfur source to a mixed solution of alcohol and water and carrying out a hydrothermal reaction. Tin disulfide is heat-treated to obtain tin dioxide; Tin dioxide and a noble metal source are added to an alcohol solution containing a surfactant and heated to react, thus obtaining a tin dioxide-supported binary noble metal nanoparticle electrocatalyst. The heating reaction is carried out at a temperature of 80-180 ℃ for 2-10 h.

[0006] The SnS2 prepared in this invention has a flake structure, which is completely oxidized into SnO2 flakes after calcination. The morphology of the SnS2 flakes allows for the uniform loading of noble metals onto the SnO2 surface. Compared to SnS2 flakes, SnO2 exhibits better stability and corrosion resistance. Furthermore, the oxygen on the SnO2 surface coordinates with the metal to form strong interfacial interactions, promoting the formation of oxygen defects on the tin dioxide surface and providing more abundant sites for the anchoring of noble metals, thus significantly improving the uniformity of the noble metal nanoparticles. Mixing tin dioxide with two noble metal sources in an alcohol and using surfactants such as P123 to control the growth rate of metal particles on the support prevents the metal particles from agglomerating into large particles, thereby improving the stability of the electrocatalyst. Simultaneously, tin dioxide and the two noble metal sources can yield an electrocatalyst with uniformly dispersed metal particles and enhanced binding force to the support at a relatively low loading temperature.

[0007] The preparation method of this electrocatalyst is simple, and the resulting electrocatalyst particles are dispersed, which can reduce the loading of noble metal nanoparticles and effectively control the size of noble metal nanoparticles in the range of 1-10 nm. This size is beneficial to exert the catalytic activity of noble metals.

[0008] In some other embodiments, the tin source is one or more of stannate, tin sulfate, tin tetrachloride, tin tetrachloride pentahydrate, tetramethyltin, tetraethyltin, tetrabutyltin, tin alkoxide, tin acetylacetone, tin acetate, and tin fluoride; The sulfur source is one or more of thiourea, sulfides, thiosulfates, polysulfides, thioacetic acid, and thioacetamide; The alcohol is one or two of ethanol, ethylene glycol and isopropanol; Preferably, the tin source is tin tetrachloride, the sulfur source is thioacetamide, and the alcohol is ethylene glycol.

[0009] In some other embodiments, the mass ratio of tin source to sulfur source is (85-90):(148-152); The hydrothermal reaction temperature is 80-200℃, and the hydrothermal reaction time is 6-78 h; during the heat treatment process, tin dioxide forms a large number of oxygen defects on the surface.

[0010] Preferably, the mass ratio of the tin source to the sulfur source is (87-88):(150-151). The hydrothermal reaction temperature is 150-160℃, and the hydrothermal reaction time is 20-25h.

[0011] Specifically, the mass ratio of tin tetrachloride pentahydrate to thioacetamide is 87.68:150.26. The volume ratio of alcohol to water in the alcohol-water mixture is (3-5):(2-5); the concentration of tin tetrachloride pentahydrate is 7.0-7.2×10⁻⁶. -3 mol / L. The hydrothermal reaction was carried out at 160 °C for 24 h; after the hydrothermal reaction was completed, the product was washed with deionized water, centrifuged, and vacuum dried at 60 °C to obtain tin disulfide.

[0012] In some other embodiments, the heat treatment temperature is 400-900 °C, the heat treatment time is 20-120 min, and the heat treatment atmosphere is air or oxygen; Preferably, the heat treatment temperature is 550-650 °C, the heat treatment time is 20-40 min, and the heat treatment atmosphere is air.

[0013] Specifically, the heat treatment involves calcining in air at 600 °C for 30 min.

[0014] In some other embodiments, the precious metal source is any two of the following: platinum source, palladium source, iridium source, ruthenium source, and rhodium source; The surfactant is one or more of polyether P123, hexadecyltrimethylammonium bromide, sodium dodecyl sulfonate, and glutathione; The alcohol is one or more selected from ethanol, isopropanol, and ethylene glycol; The platinum source is selected from one or more of acetylacetonate platinum, chloroplatinic acid, tetrachloroplatinic acid, platinum tetrachloride, sodium tetrachloroplatinate, potassium tetrachloroplatinate, sodium chloroplatinate, and potassium chloroplatinate. The iridium source is selected from one or more of iridium chloride, iridium nitrate, iridium acetylacetone, and potassium hexachloroiridate; The ruthenium source is selected from one or more of ruthenium dioxide, ruthenium chloride, ruthenium nitrate, ruthenium sulfate, ruthenium acetate, and ruthenium acetylacetone. The palladium source is selected from one or more of palladium acetylacetonate, palladium chloropalladate, palladium nitrate, palladium chloride, sodium chloropalladate, and potassium chloropalladate. The rhodium source is selected from one or more of rhodium trichloride, rhodium acetate, rhodium oxide, and rhodium acetylacetonate; Preferably, the surfactant is polyether p123, the alcohol is ethylene glycol, and the noble metal source is a platinum source and an iridium source; The platinum source is chloroplatinic acid; the iridium source is potassium hexachloroiridate; the ruthenium source is ruthenium chloride; the palladium source is palladium acetylacetonate; and the rhodium source is rhodium trichloride.

[0015] In some other embodiments, the mass ratio of tin dioxide to the total loaded noble metal is (1-4):(4-1).

[0016] The heating reaction is carried out in an inert atmosphere by oil bath heating at a temperature of 110-130℃ for 2-4 hours.

[0017] The specific reaction process includes: taking a surfactant such as polyether P123 and sonicating it until it is completely dissolved in an alcohol; further, the alcohol is one or more of ethanol, isopropanol, or ethylene glycol, preferably ethylene glycol. Then, two noble metal sources and tin dioxide are added, and the resulting mixed solution is purged with argon gas for 30 minutes to remove air, then sealed. After sonication for 30 minutes, it is heated in an oil bath at 80-180 °C for 2-10 hours under an argon atmosphere of 50-300 mL / min, preferably at 120 °C for 3 hours under an argon atmosphere of 150 mL / min. After the reaction is complete, the mixture is repeatedly washed with ethanol and deionized water, centrifuged, and then vacuum dried. The resulting product is a composite electrocatalyst of tin dioxide-supported binary noble metal nanoparticles.

[0018] The inventors' research revealed that traditional methods for loading noble metal nanoparticles onto supports all employ high-temperature calcination. However, high-temperature calcination promotes the volatilization of metal particles, leading to metal agglomeration and hindering the synergistic effect between the support and the metal particles. In contrast, this invention mixes tin dioxide with two noble metal sources in an alcohol, and uses surfactants such as P123 to control the growth rate of metal particles on the support, preventing agglomeration into large particles and thus reducing the stability of the electrocatalyst. Then, through low-temperature heat treatment, an electrocatalyst with uniformly dispersed metal particles and enhanced binding force to the support is obtained.

[0019] In a second aspect, the present invention provides a tin dioxide-supported binary noble metal nanoparticle electrocatalyst prepared by the preparation method described in the first aspect. The electrocatalyst includes a tin dioxide support and a noble metal active component, wherein the noble metal active component is supported on the tin dioxide support and is selected from any two of platinum, palladium, iridium, ruthenium, and rhodium.

[0020] Tin dioxide exhibits excellent chemical stability due to its numerous metal-oxygen covalent bonds. The tin dioxide metal oxide synthesized in this invention, with its high stability and abundant surface oxygen-containing coordination sites, is used as a support for anchoring noble metals. Through strong metal-oxygen interactions, it slows down the dissolution, migration, and detachment of platinum nanoparticles, thereby improving the catalyst's corrosion resistance and anti-sintering properties.

[0021] This invention utilizes tin dioxide-supported binary noble metal nanoparticles, which can effectively balance the adsorption energies of hydrogen and hydroxyl groups during the reaction process through the interaction of electronic structures. At the same time, the strong anchoring effect of the support ensures the structural stability of the nanoparticles during the reaction, significantly improving the activity and durability of the hydrogenation reaction.

[0022] In some other embodiments, the loaded binary noble metal nanoparticles have a particle size of 1-10 nm; controlling the noble metal nanoparticles to be 1-10 nm provides a larger number of active sites due to their smaller size.

[0023] The loading of binary noble metals in the tin dioxide-supported binary noble metal nanoparticle electrocatalysts is 10-40 wt%.

[0024] Specifically, the binary noble metal nanoparticles are one or more of the following: platinum / iridium nanoparticles, platinum / palladium nanoparticles, platinum / ruthenium nanoparticles, and platinum / rhodium nanoparticles.

[0025] More specifically, the mass ratio of platinum / iridium nanoparticles is (17-20):(17-37).

[0026] Thirdly, the present invention provides the application of the tin dioxide-supported binary noble metal nanoparticle electrocatalyst described in the second aspect in anion exchange membrane fuel cells.

[0027] Fourthly, the present invention provides a hydrogen-oxygen fuel cell anode, which employs the tin dioxide-supported binary noble metal nanoparticle electrocatalyst described in the second aspect.

[0028] The beneficial effects of this invention are: (1) This invention prepares tin disulfide first, and then prepares tin dioxide support by heating tin disulfide. This preparation process can directionally obtain a high-performance catalyst support rich in stable oxygen vacancies and with excellent microstructure. It provides a widely available and low-cost raw material for constructing high-performance, long-life noble metal electrocatalysts. Moreover, its preparation process is simple, mild, and easy to control, which is conducive to large-scale and reproducible production. While ensuring high performance, it significantly reduces the overall manufacturing cost of the catalyst, laying a solid foundation for its commercial application.

[0029] Meanwhile, at a lower temperature, the noble metal precursor was mixed with the aforementioned SnO2 support in an alcohol solvent, and the mixture was controlled using the surfactant P123. The sustained-release effect of P123 allowed sufficient time for the noble metal precursor to be transported and stably anchored at these specific sites, achieving extremely high dispersion and uniformity of the noble metal nanoparticles. The low-temperature environment thermodynamically weakened the driving forces of particle migration and Ostwald ripening.

[0030] Not only were small-sized particles obtained, but the superior stability of these particles under service conditions was also ensured, effectively preventing deactivation.

[0031] (2) The tin dioxide support used in this invention has a high specific surface area and rich surface properties, which can efficiently load and highly disperse binary noble metal nanoparticles, significantly increasing the exposure density of active sites. At the same time, the large number of metal-oxygen bonds and controllable oxygen vacancy defects on the support surface provide strong anchoring sites for the noble metal active components. Through strong metal-support interaction, the migration, aggregation and loss of nanoparticles during the reaction process are effectively suppressed, thereby ensuring the long-term stability of the catalyst active area.

[0032] The strong interfacial interaction between the tin oxide support and the binary noble metal nanoparticles constructs a unique "metal-oxide" two-phase catalytic interface. This interface not only optimizes the electronic structure but also provides diverse adsorption sites for reaction intermediates, dynamically modulating their adsorption / desorption behavior, effectively reducing the reaction energy barrier, and thus significantly enhancing the intrinsic catalytic activity of the catalyst for target reactions (such as the hydroxide reaction).

[0033] (3) Tin dioxide support itself has excellent thermodynamic stability and chemical inertness. Especially in the high potential and strong oxidation environment of fuel cell operation, it exhibits corrosion resistance and oxidation resistance far exceeding that of traditional carbon support. This characteristic fundamentally solves the problem of overall catalyst structure collapse caused by the degradation of support material, and greatly improves the cycle life and durability of composite catalyst in long-term operation.

[0034] In summary, by cleverly utilizing the characteristics of tin dioxide support, this invention has successfully prepared a composite electrocatalyst that combines high activity, high stability, and low cost, effectively overcoming the core bottleneck faced by existing noble metal catalysts in applications such as anion exchange membrane fuel cells. Attached Figure Description

[0035] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0036] Figure 1The XRD patterns of the catalysts prepared in Example 1 and Comparative Example 1 are shown below. Figure 2 The image shows a TEM image of the catalyst prepared in Example 1 of this invention. Figure 3 XPS spectra of tin dioxide / platinum in Example 1 and Comparative Example 1 of this invention; Figure 4 XPS spectra of tin dioxide / iridium in Example 1 and Comparative Example 1 of this invention; Figure 5 The LSV curves are shown in Embodiment 1 and Comparative Examples 1-2 of this invention; Figure 6 The it curves are from Embodiment 1 and Comparative Examples 1-2 of this invention; Figure 7 Here are TEM images of tin dioxide / platinum in Comparison 1 of this invention; Figure 8 This is a TEM image of tin dioxide / iridium in Example 1 of the present invention; Figure 9 The LSV curves are shown in Embodiment 2 and Comparative Examples 1-2 of this invention; Figure 10 The LSV curves are from Comparative Examples 1-2 of Embodiment 3 of the present invention. Detailed Implementation

[0037] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0038] As mentioned earlier, carbon-supported platinum metal (elemental or alloyed) remains the mainstream catalyst for both the cathode and anodic reactions of AEMFCs. Compared to the oxygen reduction reaction at the cathode, the kinetics of the hydroxide reaction at the anode are two orders of magnitude slower under alkaline conditions than under acidic conditions, thus placing higher demands on the loading of noble metals. Simultaneously, during the catalytic process, the noble metal platinum undergoes Ostwald ripening, and the carbon black support is easily oxidized and corroded at high potentials. Both of these factors contribute to the destruction of the catalyst structure and a significant decrease in stability. Furthermore, the electrostatic interaction between the carbon black support and the noble metal is singular and weak, limiting the controllable space of the support for the active sites of the noble metal, severely hindering the commercialization of AEMFCs. Therefore, this invention develops a novel hydroxide reaction catalyst that combines high intrinsic activity with excellent structural stability.

[0039] To enable those skilled in the art to better understand the technical solutions of this disclosure, the technical solutions of this disclosure will be described in detail below with reference to specific embodiments.

[0040] Example 1 A tin dioxide-supported binary platinum / iridium nanoparticle electrocatalyst for hydroxide reaction and its preparation method thereof, specifically including the following steps: The preparation method of tin dioxide is as follows: 87.68 mg of tin tetrachloride pentahydrate and 150.26 mg of thioacetamide were completely dissolved in a mixed solution of 20 mL of deionized water and 15 mL of ethylene glycol. The resulting solution was placed in a reaction vessel and then heated in a forced-air oven at 160 °C for 24 h. After the reaction was complete, the mixture was repeatedly washed with ethanol and deionized water, centrifuged, and finally dried in a vacuum drying oven at 60 °C. The obtained product was tin disulfide. 70 mg of tin disulfide was placed in a porcelain boat and calcined in a muffle furnace at 600 °C for 30 min to obtain tin dioxide.

[0041] The method for loading platinum and iridium onto tin dioxide is as follows: Take 100 mg of polyether P 123 The solution was sonicated in 20 mL of ethylene glycol until completely dissolved. Then, 15.1 mg of tin dioxide, 19.8 mg of potassium hexachloroiridate, and 120 μL of 0.2 M chloroplatinic acid were added to prepare a mixed solution. After purging the mixed solution with argon gas for 30 min, the solution was sealed and sonicated for 30 min. Then, it was heated in an oil bath at 120 °C for 3 h under an argon atmosphere of 150 mL / min. After the reaction was completed, the solution was repeatedly washed with ethanol and water, centrifuged, and finally dried in a vacuum drying oven at 60 °C. The product obtained was a composite electrocatalyst of tin dioxide supported on platinum-iridium nanoparticles (platinum loading of 17 wt.% and iridium loading of 28 wt.%), labeled as tin dioxide / platinum / iridium (platinum 17 wt.% and iridium 28 wt.%).

[0042] Comparative Example 1 Unlike Example 1, tin dioxide was loaded with only platinum or iridium. The other preparation methods were the same as in Example 1, and tin dioxide-loaded platinum nanoparticles and tin dioxide-loaded iridium nanoparticles were prepared, respectively labeled as tin dioxide / platinum and tin dioxide / iridium.

[0043] Comparative Example 2 Commercial platinum / carbon catalyst, wherein the platinum loading is 20 wt.%.

[0044] The catalysts prepared in Example 1 and Comparative Example 1 were characterized by XRD, and the results are as follows: Figure 1 As shown. By Figure 1 It can be seen that the catalyst in Example 1 contains characteristic peaks of both platinum and iridium, indicating that tin dioxide was successfully loaded with platinum and iridium.

[0045] The catalyst of Example 1 was characterized by TEM, and the results are as follows: Figure 2 As shown. By Figure 2 It can be seen that the average particle size of the catalyst in Example 1 is about 5 nm. The catalyst of Comparative Example 1 was characterized by TEM, and the results are as follows: Figure 7 and Figure 8 As shown. By Figure 7 It can be seen that the average particle size of tin dioxide / platinum is around 4 nm. From... Figure 8 It can be seen that the average particle size of tin dioxide / iridium is around 2 nm.

[0046] The obtained tin dioxide-supported binary platinum / iridium nanoparticle composite electrocatalyst was characterized by XPS, such as... Figure 3-4 As shown, the catalyst in Example 1 contains peaks of both platinum and iridium, indicating that tin dioxide was successfully loaded with platinum and iridium.

[0047] The prepared catalyst was subjected to a hydroxide reaction test, and the specific test procedure is as follows: Take 2 mg of the composite catalyst prepared in Example 1 above, add 200 μL of isopropanol, 768 μL of water and 32 μL of a 5 wt.% Nafion solution, and sonicate for 2 h to obtain a uniform slurry. Take 10 μL of the slurry and add it dropwise to a 0.196 cm⁻¹ solution. 2 The glassy carbon electrode surface was dried in a fume hood for 2 hours to obtain a loading of 0.2 mg / cm³. 2 The working electrode was a platinum wire electrode as the counter electrode, an Hg / HgO electrode as the reference electrode, and a 0.1 M potassium hydroxide solution as the electrolyte. Hydrogen gas was passed through the solution at a flow rate of 510 mL / min for 30 min until the solution was saturated with hydrogen.

[0048] Cyclic voltammetry curves were obtained by fixing the working electrode in a three-electrode electrolytic cell using an electrochemical workstation and scanning at a rate of 50 mV / s. Polarization curves were obtained at different rotational speeds of 400-2500 rpm / min and a linear scan rate of 1 mV / s. Stability was tested for 10 hours at a constant voltage of 0.05 V vs. RHE using the amperometric chronoamperometry method.

[0049] The LSV curves of the catalysts in Example 1, Comparative Example 1, and Comparative Example 2 were measured as follows: Figure 5 As shown, by Figure 5 It can be seen that the composite electrocatalyst in Example 1 achieved a half-wave potential of 0.012 V (vs. RHE). The half-wave potentials of the tin dioxide / platinum and tin dioxide / iridium electrocatalysts in Comparative Example 1 were both 0.026 V (vs. RHE). The test results are as follows... Figure 6 As shown, the composite electrocatalyst in Example 1 showed a 13% decrease in current during the 10-hour test, which was superior to the tin dioxide / platinum (39%) and tin dioxide / iridium electrocatalysts in Comparative Example 1 (26%) and the commercial platinum / carbon (40%) in Comparative Example 2.

[0050] Example 2 A tin dioxide-supported binary platinum / iridium nanoparticle electrocatalyst for hydroxide reaction and its preparation method thereof, specifically including the following steps: The difference from Example 1 lies in the different contents of platinum and iridium loaded on it; the other preparation steps are the same as in Example 1. Specifically, the method for loading platinum and iridium onto tin dioxide is as follows: Take 100 mg of polyether P 123 The solution was sonicated until completely dissolved in 20 mL of ethylene glycol. Then, 15.1 mg of tin dioxide, 9.9 mg of potassium hexachloroiridate, and 120 μL of 0.2 M chloroplatinic acid were added to prepare a mixed solution. Argon gas was passed through the mixed solution for 30 min to purge the air, and the solution was sealed. After sonication for 30 min, the solution was heated in an oil bath at 120 °C for 3 h under an argon atmosphere of 150 mi / min. After the reaction was completed, the solution was repeatedly washed with ethanol and water, centrifuged, and finally dried in a vacuum drying oven at 60 °C. The product obtained was a composite electrocatalyst of tin dioxide supported on platinum-iridium nanoparticles (platinum loading of 20 wt.% and iridium loading of 17 wt.%), labeled as tin dioxide / platinum / iridium (platinum 20 wt.% and iridium 17 wt.%).

[0051] The tin dioxide / platinum / iridium (platinum 20 wt.%, iridium 17 wt.%) prepared in Example 2 was subjected to a hydroxide reaction, and the LSV curve was tested as follows. Figure 9 As shown. By Figure 9 It can be seen that the tin dioxide / platinum / iridium (platinum 20 wt.%, iridium 17 wt.%) composite electrocatalyst prepared in Example 2 achieved a half-wave potential of 0.014 V (vs. RHE). The tin dioxide / platinum composite electrocatalyst prepared in Comparative Example 1 had a half-wave potential of 0.026 V (vs. RHE).

[0052] Example 3 A tin dioxide-supported platinum / iridium nanoparticle electrocatalyst for hydroxide reaction and its preparation method thereof, specifically including the following steps: The difference from Example 1 lies in the different contents of platinum and iridium loaded on it; the other preparation steps are the same as in Example 1. Specifically, the method for loading platinum and iridium onto tin dioxide is as follows: Take 100mg of polyether P 123The solution was sonicated until completely dissolved in 20 mL of ethylene glycol. Then, 15.1 mg of tin dioxide, 29.7 mg of potassium hexachloroiridate, and 120 μL of 0.2 M chloroplatinic acid were added to prepare a mixed solution. Argon gas was bubbled through the solution for 30 min to purge air, and the solution was sealed. After sonication for 30 min, the solution was heated in an oil bath at 120 °C for 3 h under an argon atmosphere of 150 mL / min. After the reaction was complete, the solution was repeatedly washed with ethanol and water, centrifuged, and finally dried in a vacuum drying oven at 60 °C. The resulting product was a composite electrocatalyst of tin dioxide supported on platinum / iridium nanoparticles (platinum loading of 15 wt.% and iridium loading of 37 wt.%). It was labeled as tin dioxide / platinum / iridium (platinum 15 wt.%, iridium 37 wt.%).

[0053] The tin dioxide / platinum / iridium (platinum 15 wt.%, iridium 37 wt.%) prepared in Example 3 was subjected to a hydroxide reaction, and the LSV curve was tested as follows. Figure 10 As shown. By Figure 10 It can be seen that the tin dioxide / platinum / iridium (platinum 15 wt.%, iridium 37 wt.%) composite electrocatalyst prepared in Example 3 achieved a half-wave potential of 0.015 V (vs. RHE).

[0054] Example 4 A tin dioxide-supported binary platinum / palladium nanoparticle electrocatalyst for hydroxide reaction and its preparation method specifically include: The difference from Example 1 is that the loaded noble metals are platinum and palladium. The other preparation steps are the same as in Example 1. Specifically, the method for loading platinum and palladium onto tin dioxide is as follows: Take 100mg of polyether P 123 The solution was sonicated until completely dissolved in 20 mL of ethylene glycol. Then, 15.1 mg of tin dioxide, 12.5 mg of palladium acetylacetonate, and 120 μL of 0.2 M chloroplatinic acid were added. The resulting mixture was purged with argon gas for 30 min to remove air, then sealed. After sonication for 30 min, the mixture was heated in an oil bath at 120 °C for 3 h under an argon atmosphere of 150 mL / min. After the reaction was complete, the mixture was repeatedly washed with ethanol and water, centrifuged, and finally dried in a vacuum drying oven at 60 °C. The resulting product was a composite electrocatalyst of tin dioxide supported on platinum / palladium nanoparticles.

[0055] The tin dioxide-supported binary platinum / palladium prepared in Example 4 was subjected to a hydrogenation reaction, and the tin dioxide-supported platinum / palladium nanoparticle hydrogenation reaction composite electrocatalyst was found to have a half-wave potential of 0.016 V (vs. RHE).

[0056] Comparative Example 3 Unlike Example 4, only palladium was loaded onto tin dioxide, while the other preparation methods were the same as in Example 4, resulting in tin dioxide-loaded palladium nanoparticles.

[0057] The hydrogenation reaction performance of tin dioxide-supported palladium nanoparticles was tested, and the half-wave potential of the tin dioxide-supported palladium composite electrocatalyst was measured to be 0.049 V (vs. RHE).

[0058] Example 5 A tin dioxide-supported binary platinum / ruthenium nanoparticle electrocatalyst for hydroxide reaction and its preparation method specifically include the following steps: The difference from Example 1 is that the loaded noble metals are platinum and ruthenium. The other preparation steps are the same as in Example 1. Specifically, the method for loading platinum and ruthenium onto tin dioxide is as follows: Take 100mg of polyether P 123 The solution was sonicated until completely dissolved in 20 mL of ethylene glycol. Then, 15.1 mg of tin dioxide, 16.3 mg of ruthenium acetylacetonate, and 120 μL of 0.2 M chloroplatinic acid were added. The resulting mixture was purged with argon gas for 30 min to remove air, then sealed. After sonication for 30 min, the mixture was heated in an oil bath at 180 ℃ for 8 h under an argon atmosphere of 150 mL / min. After the reaction was complete, the mixture was repeatedly washed with ethanol and water, centrifuged, and finally dried in a vacuum drying oven at 60 ℃. The resulting product was a composite electrocatalyst of tin dioxide supported on platinum / ruthenium nanoparticles.

[0059] The tin dioxide-supported binary platinum / ruthenium prepared in Example 5 was subjected to a hydrogenation reaction, and the tin dioxide-supported platinum / palladium nanoparticle hydrogenation reaction composite electrocatalyst was found to have a half-wave potential of 0.014 V (vs. RHE).

[0060] Comparative Example 4 Unlike Example 5, tin dioxide was only loaded with ruthenium, while the other preparation methods were the same as in Example 5, resulting in tin dioxide-loaded ruthenium nanoparticles.

[0061] The hydrogenation reaction performance of tin dioxide-supported ruthenium nanoparticles was tested, and the half-wave potential of the tin dioxide-supported ruthenium composite electrocatalyst was measured to be 0.036 V (vs. RHE).

[0062] Example 6 A tin dioxide-supported binary platinum / rhodium nanoparticle electrocatalyst for hydroxide reaction and its preparation method specifically include the following steps: The difference from Example 1 is that the loaded noble metals are platinum and rhodium. The other preparation steps are the same as in Example 1. Specifically, the method for loading platinum and rhodium onto tin dioxide is as follows: 100 mg of polyether P123 was sonicated until it was completely dissolved in 20 mL of ethylene glycol. Then, 15.1 mg of tin dioxide, 8.6 mg of rhodium chloride, and 120 μL of 0.2 M chloroplatinic acid were added. The resulting mixture was purged with argon gas for 30 min to remove air, then sealed. After sonication for 30 min, the mixture was heated in an oil bath at 120 °C for 3 h under an argon atmosphere of 150 mL / min. After the reaction was complete, the mixture was repeatedly washed with ethanol and water, centrifuged, and finally dried in a vacuum drying oven at 60 °C. The resulting product was a composite electrocatalyst of tin dioxide supported on platinum / rhodium nanoparticles.

[0063] The tin dioxide-supported binary platinum / rhodium prepared in Example 6 was subjected to a hydrogenation reaction, and the tin dioxide-supported platinum / rhodium nanoparticle hydrogenation reaction composite electrocatalyst was found to have a half-wave potential of 0.014 V (vs. RHE).

[0064] Comparative Example 5 Unlike Example 6, tin dioxide was only loaded with rhodium, while the other preparation methods were the same as in Example 5, resulting in tin dioxide-loaded rhodium nanoparticles.

[0065] The hydrogenation reaction performance of tin dioxide-supported rhodium nanoparticles was tested, and the half-wave potential of the tin dioxide-supported rhodium composite electrocatalyst was measured to be 0.045 V (vs. RHE).

[0066] Comparative Example 6 Unlike Example 1, the preparation method of tin dioxide was omitted, and commercially available tin dioxide was used directly as the support. Other preparation methods were the same as in Example 1. The half-wave potential of the composite electrocatalyst was measured to be 0.045 V (vs. RHE).

[0067] Studies have found that commercially available SnO2 is often in granular form, resulting in poor utilization of precious metals and poor loading dispersion. This invention, however, produces sheet-like SnO2. The preparation of sheet-like SnO2 often requires the addition of surfactants or reducing organic compounds to inhibit the growth of specific crystal planes of tin dioxide, thereby controlling its growth into SnO2 nanosheets. SnS2 has a CdI2-type layered crystal structure; therefore, this patent synthesizes layered SnS2 via a hydrothermal method, followed by calcination to replace S in the crystal lattice with O, preserving the layered morphology of the SnS2 precursor.

[0068] Comparative Example 7 Unlike Example 1, the method for loading platinum and iridium onto tin dioxide employs a conventional high-temperature calcination method; other preparation methods are the same as in Example 1. Specifically, the high-temperature calcination method for loading platinum and iridium onto tin dioxide is as follows: The half-wave potential of the composite electrocatalyst was measured to be 0.086 V (vs. RHE).

[0069] Studies have found that metal particles synthesized by high-temperature calcination undergo chemical reactions through solid-state diffusion of metal atoms, a top-down process. This reaction is not only energy-intensive, but also results in poor uniformity of metal nanoparticle size, making them prone to agglomeration and hindering the exposure of metal active sites, thus reducing the utilization rate and catalytic activity of precious metals. In contrast, the electrocatalyst in this invention is prepared using a mild, low-cost wet chemical reduction method. SnO2 support is mixed with two precious metal sources in a low-alcohol solution, and surfactant P123 is used to control the growth rate of metal particles on the support, preventing agglomeration into large particles. Through mild reduction with low-temperature alcohol, a composite electrocatalyst of precious metal nanoparticles uniformly supported on the SnO2 support surface is obtained. The accompanying drawings also show that the obtained composite electrocatalyst exhibits a uniform distribution of supported platinum / iridium nanoparticles, with an average particle size of approximately 5 nm.

[0070] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a tin dioxide-supported binary noble metal nanoparticle electrocatalyst, characterized in that, Includes the following steps: Tin disulfide is prepared by adding a tin source and a sulfur source to a mixed solution of alcohol and water and carrying out a hydrothermal reaction. Tin disulfide is heat-treated to obtain tin dioxide; Tin dioxide and a noble metal source are added to an alcohol solution containing a surfactant and heated to react, thus obtaining a tin dioxide-supported binary noble metal nanoparticle electrocatalyst. The heating reaction is carried out at a temperature of 80-180 ℃ for 2-10 h.

2. The preparation method according to claim 1, characterized in that, The tin source is one or more of the following: stannate, tin sulfate, tin tetrachloride, tin tetrachloride pentahydrate, tetramethyltin, tetraethyltin, tetrabutyltin, tin alkoxide, tin acetylacetone, tin acetate, and tin fluoride; The sulfur source is one or more of thiourea, sulfides, thiosulfates, polysulfides, thioacetic acid, and thioacetamide; The alcohol is one or two of ethanol, ethylene glycol and isopropanol; Preferably, the tin source is tin tetrachloride, the sulfur source is thioacetamide, and the alcohol is ethylene glycol.

3. The preparation method according to claim 1, characterized in that, The mass ratio of the tin source to the sulfur source is (85-90):(148-152); The hydrothermal reaction temperature is 80-200℃, and the hydrothermal reaction time is 6-78 h; Preferably, the mass ratio of the tin source to the sulfur source is (87-88):(150-151); The hydrothermal reaction temperature is 150-160℃, and the hydrothermal reaction time is 20-25 h.

4. The preparation method according to claim 1, characterized in that, The heat treatment temperature is 400-900 ℃, the heat treatment time is 20-120 min, and the heat treatment atmosphere is air or oxygen; Preferably, the heat treatment temperature is 550-650℃, the heat treatment time is 20-40 min, and the heat treatment atmosphere is air.

5. The preparation method according to claim 1, characterized in that, The precious metal source is any two of the following: platinum source, palladium source, iridium source, ruthenium source, and rhodium source; The surfactant is one or more of polyether p123, hexadecyltrimethylammonium bromide, sodium dodecyl sulfonate, and glutathione; The platinum source is selected from one or more of acetylacetonate platinum, chloroplatinic acid, tetrachloroplatinic acid, platinum tetrachloride, sodium tetrachloroplatinate, potassium tetrachloroplatinate, sodium chloroplatinate, and potassium chloroplatinate. The iridium source is selected from one or more of iridium chloride, iridium nitrate, iridium acetylacetone, and potassium hexachloroiridate; The ruthenium source is selected from one or more of ruthenium dioxide, ruthenium chloride, ruthenium nitrate, ruthenium sulfate, ruthenium acetate, and ruthenium acetylacetone. The palladium source is selected from one or more of palladium acetylacetonate, palladium chloropalladate, palladium nitrate, palladium chloride, sodium chloropalladate, and potassium chloropalladate. The rhodium source is selected from one or more of rhodium trichloride, rhodium acetate, rhodium oxide, and rhodium acetylacetonate; Preferably, the alcohol is ethylene glycol; the noble metal source is a platinum source and an iridium source; The platinum source is chloroplatinic acid; the iridium source is potassium hexachloroiridate. The ruthenium source is ruthenium chloride; the palladium source is palladium acetylacetone; and the rhodium source is rhodium trichloride.

6. The preparation method according to claim 1, characterized in that, The mass ratio of tin dioxide to the total loaded noble metal is (1-4):(4-1); The heating reaction is carried out in an inert atmosphere by oil bath heating, the temperature of the heating reaction is 110-130℃, and the heating reaction time is 2-4 h.

7. A tin dioxide-supported binary noble metal nanoparticle electrocatalyst prepared by the preparation method according to any one of claims 1-6, characterized in that, The electrocatalyst comprises a tin dioxide support and a noble metal active component, wherein the noble metal active component is supported on the tin dioxide support and is selected from any two of platinum, palladium, iridium, ruthenium, and rhodium.

8. The tin dioxide-supported binary noble metal nanoparticle electrocatalyst according to claim 7, characterized in that, The particle size of the binary noble metal nanoparticles is 1-10 nm; The loading of binary noble metals in the tin dioxide-supported binary noble metal nanoparticle electrocatalysts is 10-40 wt%.

9. The application of the tin dioxide-supported binary noble metal nanoparticle electrocatalyst according to claim 7 or 8 in anion exchange membrane fuel cells.

10. An anode for a hydrogen-oxygen fuel cell, characterized in that, The tin dioxide-supported binary noble metal nanoparticle electrocatalyst described in claim 7 or 8 is used.

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