Synthesis method of a platinum-enriched Pt-Co hyperbranched nanostructure catalyst
By adding platinum source, cobalt source, formaldehyde and PVP to oleamine, a one-pot solvent-heat reaction was carried out to prepare a branch structure with high density distribution, which solved the problem of Pt-Co nanodendrite branch length, and maximized the utilization rate of platinum atoms and improved catalytic activity.
Patent Information
- Application Number
- CN202211643807.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-12-20
- Publication Date
- 2025-06-13
- Estimated Expiration
- 2042-12-20
AI Technical Summary
The branch lengths of existing Pt-Co nanodendrites are too short to provide sufficient active sites, limiting catalytic activity.
A synthesis method of platinum-enriched Pt-Co hyperbranched nanostructure catalyst was adopted. By adding platinum source, cobalt source, formaldehyde and PVP to oleamine, a one-pot solvent-heat reaction was carried out to control the growth and deposition process of nanocrystals, and a high-density distribution branch structure was prepared.
The utilization rate of platinum atoms is maximized, the efficiency of oxygen reduction reaction is improved, the amount of precious metal platinum is reduced, and the catalytic activity is significantly improved.
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Figure CN115986152B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of electrochemical energy, and relates to a synthesis method of a platinum-enriched Pt-Co hyperbranched nanostructure catalyst. Background Art
[0002] Polymer electrolyte membrane fuel cells (PEMFCs) offer great potential as a renewable energy source for portable electronic devices and vehicles. Due to their high energy conversion and zero greenhouse gas emissions, the development of efficient electrocatalysts for the cathode oxygen reduction reaction (ORR) and the anode methanol oxidation reaction (MOR) is an important step in fuel cell applications. In recent years, noble metal platinum (Pt) nanomaterials have become widely used catalysts due to their excellent performance in electrooxidation reactions. However, the overall progress of fuel cells has been severely limited by the high cost and extreme scarcity of platinum. Therefore, it is necessary to find effective strategies to reduce the platinum demand and improve the atomic utilization while maintaining the catalytic performance. As a major challenge, various bimetallic catalysts, such as Pt-Pb, Pt-Ni, Pt-Cu, Pt-Rh, and Pt-Pd, have been studied to replace pure Pt catalysts. Platinum-based bimetallic catalysts with transition elements can improve the catalytic activity due to lattice strain, downshift of the d-band center, and possible synergistic effects. In the bimetallic system, Pt-Co alloy has become a potential choice due to its excellent electrooxidation reaction characteristics.
[0003] Among various Pt-Co nanocrystals, nanoporous, nanowire, nanotube, and hollow structures are very important, and they exhibit enhanced catalytic performance by maximizing their high surface-to-volume ratio and atomic utilization. In particular, from the experimental results in recent years, researchers have paid great attention to the synthesis of nanodendrites with branched structures. Despite these successes, it should be mentioned that the branch lengths of most previously prepared nanodendrites are too short and too few to provide sufficient active sites, which severely limits the catalytic activity. Therefore, the synthesis of Pt-Co nanodendrites with ultra-long branched platinum atom enrichment by a simple one-pot solvothermal method remains a great challenge. Summary of the Invention
[0004] Aiming at the technical problem that the degree of branching of Pt-Co nanodendrites in the prior art is not high and cannot provide sufficient active sites, the present invention proposes a synthesis method of a platinum-enriched Pt-Co hyperbranched nanostructure catalyst. The present invention adopts a simple and effective preparation method and a reasonable formulation design to achieve atomic-level control of the growth and deposition processes of nanocrystals, thereby preparing a fine three-dimensional nano-framework structure. The platinum-enriched Pt-Co hyperbranched nanostructure catalyst can not only improve the efficiency of the oxygen reduction reaction but also reduce the consumption of noble metals.
[0005] To achieve the above object, the technical solution of the present invention is implemented as follows:
[0006] A method for synthesizing a platinum-enriched Pt-Co hyperbranched nanostructure catalyst, wherein a platinum source, a cobalt source, formaldehyde and PVP are added to oleylamine, and after mixing and stirring, a one-pot solvothermal reaction is carried out. After the reaction is completed, the platinum-enriched Pt-Co hyperbranched nanostructure is obtained by collection, washing and centrifugation.
[0007] Further, the cobalt source is any one of cobalt acetylacetonate, cobalt nitrate, cobalt chloride or cobalt sulfate, and the platinum source is platinum acetylacetonate or chloroplatinic acid.
[0008] Further, the mass ratio of the platinum source, the cobalt source and PVP is (100-150):(100-150):(100-300).
[0009] Further, the mass-volume ratio of the platinum source to formaldehyde and oleylamine is (100-150) mg:(10-30) mL:(50-150) mL.
[0010] Preferably, the cobalt source is cobalt acetylacetonate and the platinum source is platinum acetylacetonate.
[0011] Further, the temperature of the one-pot solvothermal reaction is 110-140 °C.
[0012] Further, the temperature of the one-pot solvothermal reaction is 115-125 °C.
[0013] Preferably, the temperature of the one-pot solvothermal reaction is 120 °C.
[0014] Further, the time of the one-pot solvothermal reaction is 12-36 h.
[0015] Further, the time of the one-pot solvothermal reaction is 15-30 h.
[0016] Preferably, the time of the one-pot solvothermal reaction is 24 h.
[0017] Further, the number of branches of the platinum-enriched Pt-Co hyperbranched nanostructure catalyst prepared by the above method can reach more than 15, and the lateral width of the branches is 2.1-4.1 nm, and the longitudinal length is 60.2-70.2 nm.
[0018] Further, the application of the above platinum-enriched Pt-Co hyperbranched nanostructure catalyst in the field of electrocatalysis.
[0019] The present invention has the following beneficial effects:
[0020] 1. In the present invention, polyvinylpyrrolidone (PVP) serves as a surface capping agent and a structure-directing agent, controlling the growth direction of crystal nuclei and promoting the growth of nuclei with a high-density distribution of branched structures. Specifically, in a sealed environment of relatively high temperature and pressure, the reactivity and solubility of reactants can be greatly increased. When the crystal nuclei grow to a certain extent, as a long-chain polymer, the main chain of PVP acts as a natural aggregation inhibitor to prevent particle aggregation, capable of reducing the reaction process and inhibiting the further growth of nuclei. Moreover, the hydrophilic group (pyrrolidone) and hydrophobic group (alkyl) in PVP will promote the growth of some specific crystal planes and hinder the growth of other crystal planes. At the same time, as a structure-directing agent, PVP adsorbs on specific crystal planes, promoting the growth of nuclei along specific crystal directions to achieve growth under kinetic control. Additionally, when PVP adheres to the crystal surface, it can provide more growth sites, increase the accumulation of atoms, and thus promote the growth of crystals with a high-density distribution of branched structures, enabling the hyperbranched nanostructures to have an open surface area and more active sites, and maximizing the utilization rate of platinum atoms.
[0021] 2. In the present invention, formaldehyde serves as a reducing agent to provide a faster reduction rate, and under the synergistic effect of PVP, platinum acetylacetonate with a relatively high redox potential is more likely to deposit on the branched structures, forming a hyperbranched structure enriched with platinum atoms. Specifically, the cobalt reduction / nucleation / growth process is slower than that of Pt reduction. Only a small part of cobalt salt can be reduced, and PVP with a certain reducing ability is not sufficient to reduce Co(acac) 2 , after adding formaldehyde, as a stronger reducing agent, formaldehyde can adjust the redox potential of metal precursors and provide a faster reduction rate. In the initial stage, platinum atoms are reduced quickly, and then the deposition of Co phase accelerates, while the growth of Pt phase slows down due to the substantial depletion of Pt precursors. After the substantial consumption of Pt precursors and Co precursors, due to the driving force for forming platinum-cobalt alloy, platinum atoms diffuse and preferentially deposit on the branched structures, thus forming hyperbranched nanocrystals enriched with platinum atoms. The platinum-enriched branched structures can optimize the arrangement of surface platinum atoms, which can effectively reduce the consumption of precious metal platinum, save a part of the cost, and fully exert the catalytic performance of platinum atoms at the same time.
[0022] 3. The present invention adopts a stirring-assisted one-pot solvothermal method. By using oleylamine as the solvent, PVP as the structure-directing agent and surface capping agent, formaldehyde as the reducing agent, and platinum acetylacetonate and cobalt acetylacetonate as metal precursors, a platinum-enriched Pt-Co hyperbranched nanostructured catalyst with a special morphology is directly synthesized in one step. The combined use of PVP and formaldehyde is the key to synthesizing the hyperbranched structure in the present invention. The present invention realizes atomic-level control over the growth and deposition processes of nanocrystals, thereby preparing a fine three-dimensional nano-framework structure. The number of branches in this structure can reach more than 15, which is highly concentrated, and the lateral width of the branches is 2.1 - 4.1 nm, and the longitudinal length can reach 60.2 - 70.2 nm..
[0023] 4. When the platinum-enriched Pt-Co hyperbranched nanostructure is used as an electrocatalyst in the present invention, it exhibits excellent oxygen reduction catalytic activity. Compared with the commercial platinum-carbon (Pt / C) catalyst, the platinum-enriched Pt-Co hyperbranched nanostructure prepared in the present invention shows a high mass activity of 1.63 A mg -1 Pt, which is 12.5 times that of the commercial platinum-carbon (Pt / C) catalyst (0.13 A mg -1 Pt); its specific activity is 4.53 mA cm -2 , which is 15.1 times that of the commercial platinum-carbon Pt / C catalyst (0.30 mA cm –2 ). BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.
[0025] Figure 1 It is a TEM image of the platinum-enriched Pt-Co hyperbranched nanostructured catalyst prepared in Example 1 of the present invention.
[0026] Figure 2 It is a high-resolution TEM single-crystal Pt-Co branch atomic deposition direction diagram of Example 1 of the present invention.
[0027] Figure 3 It is a mapping schematic diagram of the enrichment of branched platinum elements in the platinum-enriched Pt-Co hyperbranched nanostructured catalyst prepared in Example 1 of the present invention.
[0028] Figure 4 It is a TEM image of the Pt-Co nanocrystals prepared in Comparative Example 1 of the present invention.
[0029] Figure 5TEM image of the Pt-Co nanocrystals prepared in Comparative Example 2 of the present invention.
[0030] Figure 6 TEM image of the Pt-Co nanocrystals prepared in Comparative Example 3 of the present invention.
[0031] Figure 7 TEM image of the Pt-Co nanocrystals prepared in Comparative Example 4 of the present invention.
[0032] Figure 8 Oxygen reduction polarization curve of the platinum-rich Pt-Co hyperbranched nanostructure catalyst prepared in Example 1 of the present invention and the commercial platinum-carbon (Pt / C) catalyst.
[0033] Figure 9 Mass activity diagram of the platinum-rich Pt-Co hyperbranched nanostructure catalyst prepared in Example 1 of the present invention and the mass activity diagram of the commercial platinum-carbon (Pt / C) catalyst.
[0034] Figure 10 Mass activity diagram of the platinum-rich Pt-Co hyperbranched nanostructure catalyst prepared in Example 1 of the present invention and the specific activity diagram of the commercial platinum-carbon (Pt / C) catalyst. Detailed implementation mode
[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
[0036] Chemical reagents: Platinum acetylacetonate (Pt(acac) 2 , 97%), cobalt acetylacetonate (Co(acac) 2 , 97%), oleylamine (OAM, 80-90%), cobalt nitrate, cobalt chloride, cobalt sulfate, chloroplatinic acid, polyvinylpyrrolidone (PVP), formaldehyde (HCHO) are all commercial reagents and have not been treated or purified. The experimental water is ultrapure water (18.2 MΩ . cm), and the absolute ethanol for the solution is of analytical grade and has not been purified.
[0037] Example 1
[0038] A synthesis method of a platinum-rich Pt-Co hyperbranched nanostructure catalyst is as follows:
[0039] Take 118 mg of platinum acetylacetonate Pt(acac) 2 and 106.9 mg of cobalt acetylacetonate Co(acac)2 , 10 mL of formaldehyde (HCHO) and 100 mg of polyvinylpyrrolidone (PVP) were added to 90 mL of OAm at one time. The above mixture was stirred with a magnetic stirrer at 60 °C for 30 min. Then, the well-mixed solution was placed in a 200 mL polytetrafluoroethylene reaction kettle, sealed with a stainless steel outer liner, and then placed in an oil bath at 120 °C and heated for 24 h, and then cooled to room temperature. The prepared black product was collected, washed twice with ethanol, and centrifuged at 5000 rpm in a centrifuge for 5 min. Finally, the cleaned platinum-enriched Pt-Co hyperbranched nanocrystals were obtained.
[0040] Figure 1 This is the TEM image of the platinum-enriched Pt-Co hyperbranched nanostructured catalyst prepared in Example 1 of the present invention. As shown in the figure, the TEM image shows that the black product is composed of hyperbranched nanostructures, and the dispersion between the hyperbranched nanostructures is good, and no large-scale agglomeration phenomenon occurs. At the same time, this figure clearly shows the degree of high branching of the platinum-enriched Pt-Co hyperbranched nanocrystal catalyst, and the number of branches of individual nanocrystal particles is dense, and the number of branches can reach more than 15. The transverse width of the branches is 2.1 - 4.1 nm, and the longitudinal length can reach 60.2 - 70.2 nm. This provides an open surface area and more active sites for it, further enhancing the electrocatalytic activity.
[0041] Figure 2 This is the high-resolution TEM single-crystal Pt-Co branch atomic deposition direction diagram of Example 1 of the present invention. Figure 2 It shows that each branch of the hyperbranched nanostructure grows along the
[100] direction, which indicates that PVP is adsorbed on specific crystal planes as a structure-directing agent, promoting the growth of the nucleus along a specific crystal direction and realizing the growth controlled by kinetics.
[0042] Figure 3 This is the mapping schematic diagram of the enrichment of branched platinum elements in the platinum-enriched Pt-Co hyperbranched nanostructured catalyst prepared in Example 1 of the present invention. It can be seen from the figure that the Pt element is more obvious, indicating that the distribution area of the Pt element is larger than that of the Co element, suggesting the phenomenon of platinum enrichment in crystal particles.
[0043] Example 2
[0044] A method for synthesizing a platinum-enriched Pt-Co hyperbranched nanostructured catalyst comprises the following steps:
[0045] Take 100 mg of chloroplatinic acid, 120 mg of cobalt nitrate, 13 mL of formaldehyde (HCHO), and 150 mg of polyvinylpyrrolidone (PVP) and add them to 50 mL of OAm at one time. Stir the above mixture with a magnetic stirrer at 60 °C for 30 min. Then, place the uniformly mixed solution in a 200 mL polytetrafluoroethylene reaction kettle, seal it with a stainless steel outer liner, and put it into an oil bath at 130 °C. Heat it for 28 h, and then cool it to room temperature. Collect the prepared black product, wash it twice with ethanol, and centrifuge it at 5000 rpm for 5 min in a centrifuge. Finally, obtain the cleaned platinum-enriched Pt-Co hyperbranched nanocrystals.
[0046] Example 3
[0047] A method for synthesizing a platinum-enriched Pt-Co hyperbranched nanostructured catalyst comprises the following steps:
[0048] Take 132 mg of platinum acetylacetonate Pt(acac) 2 、150 mg of cobalt chloride, 25 mL of formaldehyde (HCHO), and 200 mg of polyvinylpyrrolidone (PVP) and add them to 100 mL of OAm at one time. Stir the above mixture with a magnetic stirrer at 60 °C for 30 min. Then, place the uniformly mixed solution in a 200 mL polytetrafluoroethylene reaction kettle, seal it with a stainless steel outer liner, and put it into an oil bath at 140 °C. Heat it for 36 h, and then cool it to room temperature. Collect the prepared black product, wash it twice with ethanol, and centrifuge it at 5000 rpm for 5 min in a centrifuge. Finally, obtain the cleaned platinum-enriched Pt-Co hyperbranched nanocrystals.
[0049] Example 4
[0050] A method for synthesizing a platinum-enriched Pt-Co hyperbranched nanostructured catalyst comprises the following steps:
[0051] Take 150 mg of platinum acetylacetonate Pt(acac) 2 、127 mg of cobalt sulfate, 30 mL of formaldehyde (HCHO), and 300 mg of polyvinylpyrrolidone (PVP) and add them to 150 mL of OAm at one time. Stir the above mixture with a magnetic stirrer at 60 °C for 30 min. Then, place the uniformly mixed solution in a 200 mL polytetrafluoroethylene reaction kettle, seal it with a stainless steel outer liner, and put it into an oil bath at 125 °C. Heat it for 32 h, and then cool it to room temperature. Collect the prepared black product, wash it twice with ethanol, and centrifuge it at 5000 rpm for 5 min in a centrifuge. Finally, obtain the cleaned platinum-enriched Pt-Co hyperbranched nanocrystals.
[0052] Comparative Example 1
[0053] A preparation method of Pt-Co nanocrystals is as follows:
[0054] Take 118 mg of platinum acetylacetonate Pt(acac) 2 、106.9 mg of cobalt acetylacetonate Co(acac) 2 、10 mL of N,N-dimethylformamide (DMF), and 300 mg of polyvinylpyrrolidone (PVP) are added to 90 mL of OAm at one time. Stir the above mixture with a magnetic stirrer at 60 °C for 30 min. Then, place the uniformly mixed solution in a 200 mL polytetrafluoroethylene reaction kettle, seal it with a stainless steel outer lining, and put it into an oil bath at 120 °C, heat for 24 h, and then cool to room temperature. Collect the prepared black product, wash it twice with ethanol, and centrifuge it at a speed of 5000 rpm in a centrifuge for 5 min. Finally, obtain the cleaned Pt-Co nanocrystals.
[0055] Figure 4 This is the TEM image of the Pt-Co nanocrystals prepared in this comparative example. It can be seen from the figure that the obtained product is in a thorn-ball shape, and the branches are short and not obvious.
[0056] Comparative Example 2
[0057] A preparation method of Pt-Co nanocrystals is as follows:
[0058] Take 118 mg of platinum acetylacetonate Pt(acac)2, 106.9 mg of cobalt acetylacetonate Co(acac)2, 10 mL of ethylene glycol, and 300 mg of polyvinylpyrrolidone (PVP) and add them to 90 mL of OAm at one time. Stir the above mixture with a magnetic stirrer at 60 °C for 30 min. Then, place the uniformly mixed solution in a 200 mL polytetrafluoroethylene reaction kettle, seal it with a stainless steel outer lining, and put it into an oil bath at 120 °C, heat for 24 h, and then cool to room temperature. Collect the prepared black product, wash it twice with ethanol, and centrifuge it at a speed of 5000 rpm in a centrifuge for 5 min. Finally, obtain the cleaned Pt-Co nanocrystals.
[0059] Figure 5 This is the TEM image of the Pt-Co nanocrystals prepared in this comparative example. It can be seen from the figure that the obtained product has an irregular shape, fewer branches, and uneven growth.
[0060] Comparative Example 3
[0061] A preparation method of Pt-Co nanocrystals is as follows:
[0062] Take 118 mg of platinum acetylacetonate Pt(acac) 2 、106.9 mg of cobalt acetylacetonate Co(acac) 2 、10 mL of formaldehyde (HCHO), 300 mg of octadecyltrimethylammonium bromide (OTAB) are added to 90 mL of OAm at one time. Stir the above mixture with a magnetic stirrer at 60 °C for 30 min. Then, place the uniformly mixed solution in a 200 mL polytetrafluoroethylene reaction kettle, seal it with a stainless steel outer lining and put it into an oil bath at 120 °C, heat for 24 h, and then cool to room temperature. Collect the prepared black product, wash it twice with ethanol, and centrifuge it at a speed of 5000 rpm in a centrifuge for 5 min to finally obtain clean Pt-Co nanocrystals.
[0063] Figure 6 This is the TEM image of the Pt-Co nanocrystals prepared in this comparative example. It can be seen from the figure that the obtained product particles are of different sizes and are in the shape of a sea urchin.
[0064] Comparative Example 4
[0065] A method for preparing Pt-Co nanocrystals is as follows:
[0066] Take 118 mg of platinum acetylacetonate Pt(acac) 2 、106.9 mg of cobalt acetylacetonate Co(acac) 2 、10 mL of formaldehyde (HCHO), 300 mg of octadecyltrimethylammonium chloride (OTAC) are added to 90 mL of OAm at one time. Stir the above mixture with a magnetic stirrer at 60 °C for 30 min. Then, place the uniformly mixed solution in a 200 mL polytetrafluoroethylene reaction kettle, seal it with a stainless steel outer lining and put it into an oil bath at 120 °C, heat for 24 h, and then cool to room temperature. Collect the prepared black product, wash it twice with ethanol, and centrifuge it at a speed of 5000 rpm in a centrifuge for 5 min to finally obtain clean Pt-Co nanocrystals.
[0067] Figure 7 This is the TEM image of the Pt-Co nanocrystals prepared in this comparative example. It can be seen from the figure that the obtained product agglomerates together, is not evenly dispersed, and has no obvious hyperbranched structure.
[0068] Test Example
[0069] The oxygen reduction performance test of the platinum-enriched Pt-Co hyperbranched nanostructure catalyst prepared in Example 1 is as follows:
[0070] The impregnated rotating disk electrode was installed on the test device, and a bipotentiostat (AFCBP1E, Pine Instrument Co., USA) and a three-electrode system were used to measure the electrocatalytic performance of the catalyst in the oxygen reduction reaction. Among them, the working electrode was the rotating disk electrode, the reference electrode was the reversible hydrogen electrode (RHE), and the Pt sheet was used as the counter electrode (1.0×1.0 cm 2 ). All glassware such as the electrolytic cell, beaker, and gas pipe were cleaned. The oxygen reduction polarization curve (LSV) of the catalyst was tested for oxygen reduction performance in an O 2 -saturated 0.1 M HClO 4 electrolyte. The rotation speed of the working electrode was 1600 revolutions per minute (rpm), the potential scanning range was 0.05 - 1.1 V, and the scanning rate was 10 mV / s.
[0071] Figure 8 This is the oxygen reduction polarization curve graph of the platinum-enriched Pt-Co hyperbranched nanostructure catalyst prepared in Example 1 of the present invention and the commercial Pt / C catalyst. It can be seen from the graph that the half-wave potential of the Pt-Co hyperbranched nanocrystal is significantly higher than that of the commercial Pt / C catalyst, indicating that the catalytic activity of the Pt-Co hyperbranched nanocrystal is higher than that of the latter.
[0072] Figure 9 This is the mass activity graph of the platinum-enriched Pt-Co hyperbranched nanostructure catalyst prepared in Example 1 of the present invention and the mass activity graph of the commercial platinum-carbon (Pt / C) catalyst. It can be seen from the graph that the platinum-enriched Pt-Co hyperbranched nanostructure catalyst prepared in Example 1 shows a high mass activity of 1.63 A mg -1 Pt, which is 12.5 times that of the commercial Pt / C catalyst (0.13 A mg -1 Pt).
[0073] Figure 10 This is the mass activity graph of the platinum-enriched Pt-Co hyperbranched nanostructure catalyst prepared in Example 1 of the present invention and the specific activity graph of the commercial platinum-carbon (Pt / C) catalyst. It can be seen from the graph that the specific activity of the platinum-enriched Pt-Co hyperbranched nanostructure catalyst prepared in the example is 4.53 mA cm -2 , which is 15.1 times that of the commercial Pt / C catalyst (0.30 mA cm –2 ).
[0074] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.
Claims
1. A method for synthesizing a platinum-enriched Pt-Co hyperbranched nanostructure catalyst, characterized in that: A platinum source, a cobalt source, formaldehyde and PVP are added to oleylamine. After mixing and stirring, a one-pot solvothermal reaction is carried out. After the reaction is completed, the platinum-enriched Pt-Co hyperbranched nanostructure catalyst is obtained by collection, washing and centrifugation; the number of branches of the platinum-enriched Pt-Co hyperbranched nanostructure can reach more than 15, and the lateral width of the branches is 2.1-4.1 nm, and the longitudinal length is 60.2-70.2 nm.
2. The method for synthesizing a platinum-enriched Pt-Co hyperbranched nanostructure catalyst according to claim 1, characterized in that: The cobalt source is any one of cobalt acetylacetonate, cobalt nitrate, cobalt chloride or cobalt sulfate, and the platinum source is platinum acetylacetonate or chloroplatinic acid.
3. The method for synthesizing a platinum-enriched Pt-Co hyperbranched nanostructure catalyst according to claim 1 or 2, characterized in that: The mass ratio of the platinum source, the cobalt source and PVP is (100-150):(100-150):(100-300).
4. The method for synthesizing a platinum-enriched Pt-Co hyperbranched nanostructure catalyst according to claim 1 or 2, characterized in that: The mass-volume ratio of the platinum source to formaldehyde and oleylamine is (100-150) mg:(10-30) mL:(50-150) mL.
5. The method for synthesizing a platinum-enriched Pt-Co hyperbranched nanostructure catalyst according to claim 2, characterized in that: The temperature of the one-pot solvothermal reaction is 110-140 °C.
6. The method for synthesizing a platinum-enriched Pt-Co hyperbranched nanostructure catalyst according to claim 5, characterized in that: The temperature of the one-pot solvothermal reaction is 115-125 °C.
7. The method for synthesizing a platinum-enriched Pt-Co hyperbranched nanostructure catalyst according to claim 1, 2, 5 or 6, characterized in that: The time of the one-pot solvothermal reaction is 12-36 h.
8. The method for synthesizing a platinum-enriched Pt-Co hyperbranched nanostructure catalyst according to claim 7, characterized in that: The time of the one-pot solvothermal reaction is 15-30 h.