Preparation method and application of a length-controllable Pd2Sn@Pt core-shell structure catalyst

Abstract

This invention discloses a method for preparing and applying a Pd₂Sn@Pt core-shell structured catalyst with controllable length. The material is prepared by a bottom-up colloidal method, consisting of a core of intermetallic compound Pd₂Sn and a shell of Pt, exhibiting a rod-like structure with a controllable length of 15-200 nm. The Pd₂Sn@Pt core-shell structured nanomaterial combined with carbon catalyst demonstrates excellent electrocatalytic selective oxidation of ethanol to the high-value-added fine chemical acetic acid. As an anode catalyst, it is used in an electrolysis system composed of a platinum mesh cathode to couple the anodic oxidation of ethanol to acetic acid and the cathode hydrogen evolution reaction under alkaline conditions. The coupled reaction system using Pd₂Sn@Pt as the catalyst requires only approximately 0.59 V to achieve a 10 mA cm⁻¹ voltage. ‑2 The novel Pd2Sn@Pt core-shell structure catalyst material disclosed in this invention exhibits high current density and good catalytic stability. Its application in the simultaneous electrocatalytic production of acetic acid and hydrogen is a highly efficient, low-energy-consumption electrocatalytic coupling technology with significant social and economic benefits.

Description

Technical Field

[0001] This invention belongs to the field of functionalized nanomaterials and new energy technology, specifically involving the preparation of novel core-shell structured electrocatalysts, and the low-energy electrochemical co-production technology of high-value-added fine chemical acetic acid and clean energy hydrogen. Background Technology

[0002] Developing new, sustainable energy storage and conversion devices is a crucial aspect of national energy transition and holds significant strategic importance. Hydrogen, as a representative of new energy carriers, boasts advantages such as wide availability, environmental friendliness, and high energy density, and is becoming a commanding height in the future new energy field. Water electrolysis for hydrogen production is an effective strategy for low-cost production of high-purity hydrogen, attracting widespread attention from researchers both domestically and internationally. Water electrolysis for hydrogen production involves two half-reactions: the oxygen evolution reaction at the anode and the hydrogen evolution reaction at the cathode. The four-electron process of the oxygen evolution reaction at the anode exhibits slow reaction kinetics and requires a high electrode potential. The significant potential difference between the anode and cathode results in high energy consumption, severely hindering the industrial application of water electrolysis for hydrogen production.

[0003] One effective strategy to reduce energy consumption is to replace the oxygen evolution reaction (OER) at the anode with the oxidation reaction of organic compounds. Among various organic molecules, ethanol can be produced through technologies such as biomass fermentation, and it is characterized by its low price, low toxicity, relatively high boiling point, and ease of storage and transportation. Compared to the OER, the catalytic oxidation of ethanol is a thermodynamically controlled process, requiring very low overpotentials and exhibiting high energy conversion efficiency. Furthermore, the catalytic oxidation of ethanol can be used to prepare various high-value-added fine chemicals such as acetaldehyde and acetic acid. Specifically, the electrocatalytic oxidation of ethanol to produce acetic acid does not require the high temperature or high pressure conditions of industrial production, has lower equipment requirements, milder reaction conditions, and produces acetic acid with high purity, avoiding complex subsequent purification processes. On the other hand, a co-production system combining alcohol oxidation with hydrogen evolution can fundamentally avoid the danger of hydrogen and oxygen mixing and exploding during water electrolysis for hydrogen production, making it a safe, low-energy-consumption, and high-value-added catalytic reaction process.

[0004] The development of electrocatalytic coupling for the production of acetic acid and hydrogen relies heavily on efficient electrocatalysts. While platinum, a noble metal, exhibits excellent electrocatalytic activity for alcohol oxidation, its limited reserves and high cost severely hinder its practical application. Furthermore, the stability and anti-poisoning properties of platinum in alcohol oxidation require further improvement. Preparing nanoscale catalysts can reduce the amount of platinum used and improve its atomic utilization. Optimizing the electronic structure of platinum active sites by controlling the catalyst's structure, composition, and surface stress is a common strategy for regulating catalyst performance. For example, catalysts constructed with a metal core-platinum shell structure can influence the electronic states of surface platinum through the core metal elements, optimizing the binding energy between platinum sites and adsorption intermediates, thereby improving catalyst stability and anti-poisoning capabilities.

[0005] Based on the above strategies, this invention has developed a novel core-shell catalyst with an intermetallic compound core-platinum shell, namely Pd₂Sn@Pt nanorods, and achieved control over the length of the nanorods. By using Pd₂Sn@Pt / C as the anolyte catalyst for ethanol oxidation and combining it with the hydrogen evolution reaction via a platinum mesh cathode to assemble a dual-electrode electrolyzer, low-energy electrocatalytic co-production of acetic acid and hydrogen has been achieved. Summary of the Invention

[0006] To address the high energy consumption problem in current water electrolysis technology, this invention provides a novel method for preparing Pd2Sn@Pt core-shell structured materials. The length of the Pd2Sn@Pt core-shell structured catalyst is controlled by methylamine hydrochloride, and it is applied to the selective oxidation of ethanol to acetic acid at the electrocatalytic anode. Furthermore, by coupling with the cathode for hydrogen evolution, this method promotes the development of low-energy electrocatalytic hydrogen production technology.

[0007] This invention utilizes a bottom-up colloidal synthesis method to prepare monodisperse Pd2Sn nanorods with controllable length by regulating the content of methylamine hydrochloride. Furthermore, a Pt shell is grown on the surface of the Pd2Sn nanorods, giving the prepared material excellent electrocatalytic ethanol oxidation performance.

[0008] A method for preparing a Pd₂Sn@Pt core-shell structured catalyst with controllable length includes the following steps:

[0009] (1) Under nitrogen protection, palladium precursor palladium acetylacetonate, tin precursor tin acetate (II) and structure directing agent methylamine hydrochloride were dissolved in a mixed solution of oleylamine and tri-n-octylphosphine. The mixture was stirred at a constant speed to ensure thorough mixing. The mixture was reacted at 60°C for 30 minutes, then heated to 200°C within 10 minutes and reacted at 200°C for 30 minutes. Subsequently, the mixture was heated to 300°C within 40 minutes and held at this temperature for 30 minutes.

[0010] (2) After the reaction in step (1) is completed, cool to room temperature and transfer the reactants to centrifuge tubes for centrifugation and washing. Discard the supernatant, add chloroform and ethanol to the precipitate, mix by sonication, and then centrifuge and wash again. Repeat the washing operation several times and finally collect the bottom product.

[0011] (3) Dissolve the product collected in step (2), chloroplatinic acid hexahydrate and glucose monohydrate in oleylamine, stir at a constant speed to make them fully mixed, heat to 60°C under nitrogen protection and react for 10 minutes, then heat to 200°C and continue to react for 30 minutes.

[0012] (4) After the reaction in step (3) is completed, cool to room temperature and transfer the reactants to a centrifuge tube for centrifugation and washing. Discard the supernatant, add chloroform and ethanol to the precipitate, mix with sonication and then centrifuge and wash again. Repeat the above washing operation several times. Then add an appropriate amount of ammonium thiocyanate and acetone solution to the product in the centrifuge tube, disperse with sonication and then centrifuge and wash. Continue to wash the bottom precipitate with chloroform and ethanol twice. Dry the precipitate at room temperature.

[0013] (5) The sample dried in step (4) is ultrasonically mixed with carbon black, Nafion, ethanol and deionized water to obtain carbon-supported Pd2Sn@Pt catalyst.

[0014] In step (1), the ratio of the amount of palladium acetylacetone, tin(II) acetate, methylamine hydrochloride, oleylamine and tri-octylphosphine is 91.4 mg: 37.6 mg: 50.4-100 mg: 20 mL: 1 mL.

[0015] Further, in step (1), the ratio of the amount of palladium acetylacetone, tin(II) acetate, methylamine hydrochloride, oleylamine and tri-n-octylphosphine is 91.4 mg: 37.6 mg: 50.4 mg: 20 mL: 1 mL.

[0016] In step (3), the ratio of chloroplatinic acid hexahydrate, glucose monohydrate and oleylamine is 25mg:125mg:20mL;

[0017] The ratio of palladium acetylacetone, tin(II) acetate, and chloroplatinic acid hexahydrate was 0.3 mmol: 0.15 mmol: 0.06 mmol.

[0018] In step (5), the ratio of sample: carbon black: Nafion: ethanol: deionized water is 1 mg: 4 mg: 10 μL: 0.4 mL: 0.6 mL, wherein the mass percentage concentration of Nafion is 10%.

[0019] In addition to developing a method for preparing Pd2Sn@Pt core-shell structured materials, this invention also applies them to the selective oxidation of ethanol in electrocatalytic anodic reactions, developing a highly efficient and low-energy-consumption technology for the co-production of acetic acid and hydrogen based on Pd2Sn@Pt anode catalyst.

[0020] The prepared carbon-supported Pd₂Sn@Pt catalyst was uniformly drop-coated onto the surface of a glassy carbon electrode as the working electrode. An Hg / HgO electrode was used as the reference electrode, and a platinum mesh as the counter electrode. A 1M KOH + 1M ethanol solution was used as the electrolyte. The performance of the electrocatalytic ethanol oxidation reaction was tested using a three-electrode system on an electrochemical workstation. Alternatively, a two-electrode system was used with a carbon-modified Pd₂Sn@Pt glassy carbon electrode as the anode and a platinum mesh as the cathode. The performance of the electrocatalytic coupling of ethanol oxidation and hydrogen evolution was tested in a 1M KOH + 1M ethanol solution.

[0021] The beneficial effects of this invention are as follows:

[0022] The method for preparing Pd2Sn@Pt core-shell nanomaterials described in this invention is simple, and the length of the prepared core-shell nanomaterials is controllable, exhibiting good dispersibility. The prepared Pd2Sn@Pt is an excellent novel catalyst material for the selective electrocatalytic oxidation of ethanol to acetic acid. The electrocatalytic coupling reaction system based on the Pd2Sn@Pt catalyst to prepare acetic acid and hydrogen is a highly efficient and low-energy-consumption coupled electrolysis technology. Attached Figure Description

[0023] Figure 1 The images show the transmission electron microscope (TEM) images, X-ray powder diffraction (XRD) images, high-magnification TEM images, and elemental distribution maps of the Pd₂Sn@Pt nanomaterials obtained in the examples. Specifically, ac are TEM images of the Pd₂Sn@Pt nanomaterials obtained in Examples 1, 2, and 3, respectively; d is the XRD image of the Pd₂Sn@Pt nanomaterials obtained in Examples 1-3; e and f are high-magnification TEM images of the Pd₂Sn@Pt nanomaterials obtained in Example 1; and g is the elemental distribution map of the Pd₂Sn@Pt nanomaterials obtained in Example 1.

[0024] Figure 2 Cyclic voltammetry diagrams of the electrocatalytic oxidation of ethanol in a 1M KOH + 1M ethanol mixture using the Pd2Sn@Pt-based catalysts obtained in Examples 1-3 and the commercial Pt / C catalyst.

[0025] Figure 3 The NMR spectra of the electrolyte before and after testing the electrocatalytic ethanol oxidation reaction of the Pd2Sn@Pt-based catalyst obtained in Example 1 in a 1M KOH + 1M ethanol mixture are shown.

[0026] Figure 4The diagram shows a schematic of the apparatus and a linear scan curve of the electrocatalytic reaction, in which the Pd2Sn@Pt-based catalyst, Pd2Sn, or Pt / C catalyst obtained in Example 1 is used as the anode catalyst and a platinum mesh is used as the cathode catalyst, respectively, for coupled electrolysis in a 1M KOH + 1M ethanol mixture.

[0027] Figure 5 The time-current curves of the coupled electrolysis reaction in a 1M KOH + 1M ethanol mixture are shown, with the Pd2Sn@Pt-based catalyst, Pd2Sn, or Pt / C catalyst obtained in Example 1 as the anode catalyst and a platinum mesh as the cathode catalyst. Detailed Implementation

[0028] The invention will be described below with specific examples. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, after reading the specific content of this invention, those skilled in the art can gain a clearer understanding of it and innovate upon it to better apply it to the preparation of core-shell structured catalysts and the electrocatalytic coupling of high-value-added small molecule compounds and hydrogen production technologies.

[0029] Example 1

[0030] A method for preparing and applying a Pd₂Sn@Pt core-shell structured catalyst with controllable length includes the following steps:

[0031] 91.4 mg of palladium acetylacetone, 37.6 mg of tin(II) acetate, 50.4 mg of methylamine hydrochloride, and 20 mL of oleylamine were added to a 50 mL three-necked flask. Under nitrogen protection, 1 mL of tri-n-octylphosphine was added to the reaction system. The mixture was magnetically stirred at 1000 rpm and reacted at 60 °C for 30 minutes. The temperature was then raised to 200 °C and reacted for another 30 minutes, followed by a further increase to 300 °C over 40 minutes, and reacted at this temperature for 30 minutes. The mixture was then cooled to room temperature. The reaction solution was transferred to centrifuge tubes and washed by centrifugation at 8000 rpm. The washings were then repeated twice with a mixture of chloroform and ethanol. The washed product was transferred to a 50 mL three-necked flask, and 25 mg of chloroplatinic acid hexahydrate, 125 mg of glucose monohydrate, and 20 mL of oleylamine were added. The mixture was heated to 60 °C under nitrogen atmosphere for 10 minutes, followed by a further increase to 200 °C and a reaction time of 30 minutes. After the reaction system cooled to room temperature, the reaction solution was transferred to a centrifuge tube and washed by centrifugation at 8000 rpm. The washing was then repeated twice with a mixture of chloroform and ethanol. An appropriate amount of ammonium thiocyanate and acetone solution was added to the washed precipitate, which was then ultrasonically dispersed, centrifuged, and washed twice more with chloroform and ethanol. The resulting precipitate was dried at room temperature and named Pd₂Sn-s@Pt.

[0032] Figure 1 The transmission electron microscope (TEM) image (a) and X-ray diffraction (XRD) images (d) of the Pd₂Sn-s@Pt material prepared in this embodiment are shown. TEM indicates that the prepared material has good dispersion, uniform size, and a rod-like structure with a nanorod length of approximately 15 nm. XRD shows that the material has significant (111), (013), (020), and (203) crystal planes, originating from the core layer of the intermetallic compound Pd₂Sn and the Pt shell layer on the surface. High-magnification TEM and elemental distribution maps further show that the core of the prepared core-shell structure is the intermetallic compound Pd₂Sn, and the shell is Pt. Elements Pd and Sn are uniformly distributed inside the nanoparticles, while Pt is uniformly distributed on the outer layer, indicating that the Pd₂Sn@Pt core-shell structured nanomaterial was successfully prepared.

[0033] A uniformly dispersed catalyst dispersion was obtained by mixing 1 mg of sample with 4 mg of carbon black, 10 μL of 10% Nafion solution, 0.4 mL of ethanol, and 0.6 mL of deionized water, followed by ultrasonic treatment for 2 hours. 3 μL of the catalyst dispersion was uniformly drop-coated onto the surface of a glassy carbon electrode and allowed to air dry at room temperature. The ethanol oxidation reaction was then carried out in a three-electrode system. The cyclic voltammetry curve for ethanol oxidation is shown below. Figure 2 As shown, the Pd₂Sn-s@Pt catalyst exhibits the highest mass activity of 4.75 A mg. -1 Pd+Pt The catalytic activity is significantly higher than that of commercial Pt / C, indicating that this core-shell structure material can significantly enhance the catalytic oxidation activity of ethanol.

[0034] The electrolyte before and after the catalytic reaction was analyzed by proton nuclear magnetic resonance spectroscopy, such as... Figure 3 As shown, the main product of the electrocatalytic ethanol oxidation reaction is acetic acid, and no other oxidation products were detected in the electrolyte, indicating that the Pd2Sn-s@Pt catalyst has very high selectivity for the oxidation of ethanol to acetic acid.

[0035] Using Pd₂Sn₄@Pt catalyst as the anode catalyst and platinum mesh as the cathode, a coupled electrolysis reaction was carried out in a two-electrode system, such as... Figure 4 As shown, the catalytic system exhibits a lower overpotential than both Pd₂Sn and Pt / C, requiring only approximately 0.59V to reach a voltage of 10mA cm⁻¹. -2 The current density.

[0036] also, Figure 5 The time-current curves show that the coupling system with Pd2Sn-s@Pt as the anode catalyst has better stability than the coupling catalytic system of Pd2Sn and Pt / C.

[0037] Example 2

[0038] A method for preparing and applying a Pd₂Sn@Pt core-shell structured catalyst with controllable length includes the following steps:

[0039] 91.4 mg of palladium acetylacetone, 37.6 mg of tin(II) acetate, 58.7 mg of methylamine hydrochloride, and 20 mL of oleylamine were added to a 50 mL three-necked flask. Under nitrogen protection, 1 mL of tri-n-octylphosphine was added to the reaction system. The mixture was magnetically stirred at 1000 rpm and reacted at 60 °C for 30 minutes. The temperature was then raised to 200 °C and reacted for another 30 minutes, followed by a further increase to 300 °C over 40 minutes, and reacted at this temperature for 30 minutes. The mixture was then cooled to room temperature. The reaction solution was transferred to centrifuge tubes and washed by centrifugation at 8000 rpm. The washings were then repeated twice with a mixture of chloroform and ethanol. The washed product was transferred to a 50 mL three-necked flask, and 25 mg of chloroplatinic acid hexahydrate, 125 mg of glucose monohydrate, and 20 mL of oleylamine were added. The mixture was heated to 60 °C under nitrogen atmosphere for 10 minutes, followed by a further increase to 200 °C and a reaction time of 30 minutes. After the reaction system cooled to room temperature, the reaction solution was transferred to a centrifuge tube and washed by centrifugation at 8000 r / min. The washing was then repeated twice with a mixture of chloroform and ethanol. An appropriate amount of ammonium thiocyanate and acetone solution was added to the washed precipitate, which was then ultrasonically dispersed, centrifuged, and washed twice more with chloroform and ethanol. The resulting precipitate was dried at room temperature and named the sample Pd2Sn-m@Pt.

[0040] Figure 1 The transmission electron microscope (TEM) image (b) and X-ray diffraction (XRD) images of the Pd₂Sn-m@Pt material prepared in this embodiment are shown. TEM indicates that the prepared material has good dispersion, uniform size, and a rod-like structure with nanorods approximately 35 nm in length. XRD shows that the material has significant (111), (013), (020), and (203) crystal planes, originating from the core layer of the intermetallic compound Pd₂Sn and the Pt shell layer on the surface, indicating that the Pd₂Sn@Pt core-shell structured nanomaterial was successfully prepared.

[0041] A uniformly dispersed catalyst dispersion was obtained by mixing 1 mg of sample with 4 mg of carbon black, 10 μL of 10% Nafion solution, 0.4 mL of ethanol, and 0.6 mL of deionized water, followed by ultrasonic treatment for 2 hours. 3 μL of the catalyst dispersion was uniformly drop-coated onto the surface of a glassy carbon electrode and allowed to air dry at room temperature. The ethanol oxidation reaction was then carried out in a three-electrode system. The cyclic voltammetry curve for ethanol oxidation is shown below. Figure 2 As shown.

[0042] Example 3

[0043] A method for preparing and applying a Pd₂Sn@Pt core-shell structured catalyst with controllable length includes the following steps:

[0044] 91.4 mg palladium acetylacetone, 37.6 mg tin(II) acetate, 100.0 mg methylamine hydrochloride, and 20 mL oleylamine were added to a 50 mL three-necked flask. Under nitrogen protection, 1 mL of tri-n-octylphosphine was added to the reaction system. The mixture was magnetically stirred at 1000 rpm and reacted at 60 °C for 30 minutes. The temperature was then increased to 200 °C and reacted for another 30 minutes. The temperature was then further increased to 300 °C over 40 minutes and reacted at this temperature for 30 minutes. The mixture was then cooled to room temperature. The reaction solution was transferred to centrifuge tubes and washed by centrifugation at 8000 rpm. The washings were then repeated twice with a mixture of chloroform and ethanol. The washed product was transferred to a 50 mL three-necked flask, and 25 mg of chloroplatinic acid hexahydrate, 125 mg of glucose monohydrate, and 20 mL of oleylamine were added. The mixture was heated to 60 °C for 10 minutes under a nitrogen atmosphere, then heated to 200 °C and reacted for another 30 minutes. After the reaction system cooled to room temperature, the reaction solution was transferred to a centrifuge tube and washed by centrifugation at 8000 rpm. The washings were then repeated twice with a mixture of chloroform and ethanol. An appropriate amount of ammonium thiocyanate and acetone solution was added to the washed precipitate, which was then ultrasonically dispersed, centrifuged, and washed twice more with chloroform and ethanol. The resulting precipitate was dried at room temperature and named Pd₂Sn-l@Pt.

[0045] Figure 1 The transmission electron microscope (TEM) image (c) and X-ray diffraction (XRD) images of the Pd2Sn-l@Pt material prepared in this embodiment are shown. TEM indicates that the prepared material has good dispersion, uniform size, and a rod-like structure with nanorods approximately 200 nm in length. XRD shows that the material has significant (111), (013), (020), and (203) crystal planes, originating from the core layer of the intermetallic compound Pd2Sn and the Pt shell layer on the surface, indicating that the Pd2Sn@Pt core-shell structured nanomaterial was successfully prepared.

[0046] A uniformly dispersed catalyst dispersion was obtained by mixing 1 mg of sample with 4 mg of carbon black, 10 μL of 10% Nafion solution, 0.4 mL of ethanol, and 0.6 mL of deionized water, followed by ultrasonic treatment for 2 hours. 3 μL of the catalyst dispersion was uniformly drop-coated onto the surface of a glassy carbon electrode and allowed to air dry at room temperature. The ethanol oxidation reaction was then carried out in a three-electrode system. The cyclic voltammetry curve for ethanol oxidation is shown below. Figure 2 As shown.

[0047] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made using the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for preparing a Pd₂Sn@Pt core-shell structured catalyst with controllable length, characterized in that, Includes the following steps: (1) Under nitrogen protection, palladium acetylacetone, tin(II) acetate and methylamine hydrochloride were dissolved in a mixed solution of oleylamine and tri-n-octylphosphine. The mixture was stirred at a constant speed to ensure thorough mixing. The reaction was carried out in sequence at a low temperature of 60°C, a medium temperature of 200°C and a high temperature of 300°C. (2) After the reaction in step (1) is completed, cool to room temperature and transfer the reactants to centrifuge tubes for centrifugation and washing. Discard the supernatant, add chloroform and ethanol to the precipitate, mix by sonication, and then centrifuge and wash again. Repeat the washing operation several times and finally collect the bottom product. (3) Dissolve the product collected in step (2), chloroplatinic acid hexahydrate and glucose monohydrate in oleylamine, stir at a constant speed to make them fully mixed, and carry out a low temperature reaction stage of 60°C and a medium temperature reaction stage of 200°C in sequence under nitrogen protection. (4) After the reaction in step (3) is completed, cool to room temperature and transfer the reactants to a centrifuge tube for centrifugation and washing. Discard the supernatant, add chloroform and ethanol to the precipitate, mix with sonication and then centrifuge and wash again. Repeat the above washing operation several times. Then add an appropriate amount of ammonium thiocyanate and acetone solution to the product in the centrifuge tube, disperse with sonication and then centrifuge and wash. Continue to wash the bottom precipitate with chloroform and ethanol twice. Dry the precipitate at room temperature. (5) The sample dried in step (4) is ultrasonically mixed with carbon black, Nafion, ethanol and deionized water to obtain carbon-supported Pd2Sn@Pt catalyst.

2. The preparation method according to claim 1, characterized in that, In step (1), the low-temperature reaction stage of 60°C, the medium-temperature reaction stage of 200°C, and the high-temperature reaction stage of 300°C are specifically as follows: react at 60°C for 30 minutes, then raise the temperature to 200°C within 10 minutes and react at 200°C for 30 minutes, then raise the temperature to 300°C within 40 minutes and continue to react at this temperature for 30 minutes.

3. The preparation method according to claim 1, characterized in that, In step (1), the ratio of the amount of palladium acetylacetone, tin(II) acetate, methylamine hydrochloride, oleylamine and tri-octylphosphine is 91.4 mg: 37.6 mg: 50.4-100 mg: 20 mL: 1 mL.

4. The preparation method according to claim 3, characterized in that, In step (1), the ratio of the amounts of palladium acetylacetone, tin(II) acetate, methylamine hydrochloride, oleylamine and tri-octylphosphine is 91.4 mg: 37.6 mg: 50.4 mg: 20 mL: 1 mL.

5. The preparation method according to claim 1, characterized in that, In step (3), the low-temperature reaction stage at 60°C and the medium-temperature reaction stage at 200°C are as follows: first, the temperature is raised to 60°C and reacted for 10 minutes, then the temperature is raised to 200°C and the reaction continues for 30 minutes.

6. The preparation method according to claim 1, characterized in that, In step (3), the ratio of chloroplatinic acid hexahydrate, glucose monohydrate and oleylamine is 25mg:125mg:20mL; The ratio of palladium acetylacetone, tin(II) acetate, and chloroplatinic acid hexahydrate was 0.3 mmol: 0.15 mmol: 0.06 mmol.

7. The preparation method according to claim 1, characterized in that, In step (5), the ratio of sample, carbon black, Nafion, ethanol and deionized water is 1 mg: 4 mg: 10 μL: 0.4 mL: 0.6 mL, wherein the mass percentage concentration of Nafion is 10%.

8. A Pd₂Sn@Pt core-shell structure catalyst with controllable length, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 7.

9. The application of the length-controllable Pd2Sn@Pt core-shell structure catalyst as described in claim 8 for the electrocatalytic oxidation of ethanol to acetic acid.

10. Using the length-controllable Pd2Sn@Pt core-shell structure catalyst of claim 8 as an anode catalyst for the simultaneous production of acetic acid and hydrogen through coupled electrolysis reaction.

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