Pt-Ni-Mo-Pd-Rh high-entropy alloy nanocrystalline catalyst, preparation method and application

Abstract

The application relates to a platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst, a preparation method and application, which comprises the following steps: taking a surfactant, hexacarbonylmolybdenum and corresponding metal salts of platinum, nickel, palladium and rhodium, dissolving with a solvent to obtain a first mixed solution; adding a reducing agent to the first mixed solution, stirring and mixing to obtain a second mixed solution; heating the second mixed solution, and then centrifuging to obtain a platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst. The method is simple and easy to operate, and the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst prepared by assembling nanosheets has high activity and stability in electrochemical catalyst application.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of metal nanocatalysts, in particular to a platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst, a preparation method and application thereof. BACKGROUND

[0002] Hydrogen energy is expected to become a clean energy carrier to replace fossil energy due to its zero pollution, high energy efficiency and other advantages. So far, the water electrolysis method for preparing hydrogen is a green and pollution-free and sustainable way in the renewable energy storage system. In addition, the alkaline water electrolysis technology has more advantages than the acidic water electrolysis technology, such as better long-term stability, large-scale implementation and lower cost, which greatly reduces the cost for the further development of clean energy. However, due to the involvement of a relatively complex multi-step reaction in the process of alkaline water electrolysis, the reaction kinetics is relatively slow, and the energy barrier to be overcome is also relatively high. In order to solve this problem, continuous exploration of catalysts is carried out. At present, platinum has a special d electron orbital structure, and exhibits excellent characteristics in physical and chemical properties, so it is crucial in the electrochemical energy conversion system. Therefore, greatly improving the atomic utilization of noble metal-based catalysts can maximize the catalytic activity and reduce the cost.

[0003] There are mainly two methods for the rational design of high-performance platinum-based catalysts: one is to use main group elements or transition metals to modify platinum or alloy with platinum, which is beneficial to improve the intrinsic activity of the catalyst in the alkaline hydrogen evolution reaction. High-entropy alloys have great potential in a series of efficient catalytic reactions due to their high efficiency, stability, adjustable electronic structure and cocktail effect. The understanding of the diversity of structural information and the complexity of the catalytic reaction process is not comprehensive enough, so the research and development of high-entropy alloy catalysts still face great challenges. Therefore, it is very important to effectively control the electronic structure of high-entropy alloys by different alloy elements for the preparation of high-performance catalysts.

[0004] The other method is to control the morphology of platinum-based catalysts, such as synthesizing nanowires, nanoflowers, three-dimensional nanoframes and the like. Due to the lattice disorder between elements, controllable synthesis of platinum-based nanomaterials at the atomic level, especially high-entropy alloy nanomaterials with specific morphology and size, is still a great challenge.

[0005] At present, the main methods for preparing high-entropy alloy nanocatalyst materials are carbon thermal shock method, fast moving bed pyrolysis, arc method and liquid phase synthesis method. However, these preparation methods have long reaction time, complex synthesis process and harsh reaction conditions. SUMMARY

[0006] The embodiment of the present application provides a platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst, a preparation method and application. The method is simple and easy to operate. The platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst prepared by assembling nanosheets has high activity and stability in electrochemical catalyst application.

[0007] In a first aspect, a preparation method of a platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst is provided, which comprises the following steps:

[0008] The corresponding metal salts of platinum, nickel, molybdenum, palladium and rhodium are dissolved in a solvent to obtain a first mixed solution;

[0009] A reducing agent is added to the first mixed solution, and the mixture is stirred to obtain a second mixed solution;

[0010] The second mixed solution is heated, and then centrifuged to obtain the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst.

[0011] In some embodiments, the corresponding metal salts of platinum, palladium and rhodium are platinum acetylacetone, palladium acetylacetone and rhodium acetylacetone, respectively, and the corresponding metal salt of nickel is nickel acetylacetone, nickel acetate or nickel chloride;

[0012] And / or, the surfactant is benzyltriethylammonium chloride;

[0013] And / or, the addition amount of the surfactant is that the mass ratio of the metal salt of platinum to the surfactant is 1: (40-60);

[0014] And / or, the solvent is triethylene glycol;

[0015] And / or, the addition amount of the reducing agent is that the mass ratio of the metal salt of platinum to the reducing agent is 1: (4-8).

[0016] In some embodiments, the reducing agent is glucose.

[0017] In some embodiments, the glucose is dissolved in the solvent and then added to the first mixed solution.

[0018] In some embodiments, the total amount of the solvent used in the first mixed solution and the solvent used for dissolving the glucose is 10-15 ml.

[0019] In some embodiments, the heating temperature is 230-240 DEG C, and the heating time is 1-1.5 h.

[0020] In some embodiments, oil bath heating is used.

[0021] In a second aspect, a platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst is provided, which is prepared by the preparation method of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst as described in any one of the above.

[0022] In some embodiments, the nanocrystal catalyst is in a sheet shape, and has a diameter of 15-25 nm.

[0023] In a third aspect, the application provides a use of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst as described above in an electrochemical hydrogen evolution reaction.

[0024] The application provides the following beneficial effects:

[0025] The application provides a platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst, a preparation method and an application.

[0026] The application can control the product by the type and content of the metal precursor, and obtain a platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst material assembled by nanosheets with different atomic ratios.

[0027] The platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst prepared in the application has the following two significant features. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0029] Figure 1are the XRD and XPS figures of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst prepared in Example 1 of the present application; wherein a is the XRD figure of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst, b is the XPS Pt 4f hybrid peak figure of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst, c is the XPS Ni2p hybrid peak of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst, d is the XPS Rh 3d hybrid peak of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst, e is the XPS Pd 3d hybrid peak of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst, and f is the XPS Mo 3d hybrid peak of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst.

[0030] Figure 2 are the morphology structure information figures of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst prepared in Example 1; wherein a is a TEM figure, b and c are HADDF figures at different resolutions, d is the result of energy spectrum and content spectrum figure, e is a STEM figure, and e1-e5 are corresponding element distribution figures.

[0031] Figure 3 are the morphology structure information figures of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst prepared in Example 2 of the present application; wherein a is a STEM figure, and the inserted figure in a is a corresponding energy spectrum result figure, b-f are corresponding element distribution figures.

[0032] Figure 4 are the morphology structure information figures of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst prepared in Example 3 of the present application; wherein a and b are STEM figures, c-g are corresponding element distribution figures, and e figure is a corresponding energy spectrum result figure and content spectrum figure.

[0033] Figure 5 are the morphology structure information figures of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst prepared in Example 4 of the present application; wherein a and b are STEM figures, c-g are corresponding element distribution figures, and h figure is a corresponding energy spectrum result figure and content spectrum figure.

[0034] Figure 6 are the morphology structure information figures of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst prepared in Example 5 of the present application; wherein a, b, and c figures are HADDF figures at different resolutions.

[0035] Figure 7 are the hydrogen evolution electrochemical performance figures of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst prepared in Example 1 of the present application and a commercial platinum-carbon catalyst in a 1 M KOH electrolyte saturated with nitrogen gas; a is an LSV figure of the electrochemical performance, b is a Tafel figure, and c is a corresponding overpotential value. -2 corresponding overpotential value. DETAILED DESCRIPTION

[0036] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present application.

[0037] The present application provides a preparation method of a platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst, which comprises the following steps:

[0038] 101: A surfactant, molybdenum hexacarbonyl, and metal salts corresponding to platinum, nickel, palladium, and rhodium are dissolved with a solvent to obtain a first mixed solution.

[0039] The metal salts corresponding to platinum, palladium, and rhodium are platinum acetylacetonate, palladium acetylacetonate, and rhodium acetylacetonate, respectively, and the metal salt corresponding to nickel is nickel acetylacetonate, nickel acetate, or nickel chloride.

[0040] The surfactant can be benzyltriethylammonium chloride, and the addition amount of the surfactant can be measured by the metal salt of platinum, and specifically, the mass ratio of the metal salt of platinum to the surfactant is 1: (40-60).

[0041] The solvent can be triethylene glycol.

[0042] 102: A reducing agent is added to the first mixed solution, and the mixture is stirred to obtain a second mixed solution.

[0043] The reducing agent can be glucose, and the addition amount of the reducing agent can be measured by the metal salt of platinum, and specifically, the mass ratio of the metal salt of platinum to the reducing agent is 1: (4-8), and the glucose is dissolved in a solvent and then added to the first mixed solution. The total amount of the solvent used in the first mixed solution and the solvent used for the glucose is 10-15 ml.

[0044] 103: The second mixed solution is heated.

[0045] The second mixed solution is placed in an oil bath pot and heated by oil bath, the heating temperature is 230-240℃, and the heating time is 1h-1.5h.

[0046] 104: Then cooled to room temperature, and sequentially washed, centrifuged, and dried to obtain a platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst.

[0047] The method of the present application is simple and easy to operate, the reaction needs to be heated for 1h-1.5h, the time consumption is short, and the whole process does not need complex instruments and equipment, and the cost is low.

[0048] In the present application, triethylene glycol plays a role in ionizing the solute, while providing a reducing environment to reduce metal ions into elemental substances under high temperature conditions. Meanwhile, glucose acts as a reducing agent to reduce metals in the process of metal alloying. In addition to being a source of molybdenum, the CO generated by the pyrolysis of hexacarbonylmolybdenum at 230-240°C can effectively prevent the reduced metal elements from being oxidized by O2 in the solvent.

[0049] The method of the present application can regulate the product by the type and different content of metal precursors, so that platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst materials with different atomic ratios can be obtained. The prepared catalyst has high activity and stability in electrochemical catalyst applications.

[0050] The platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst prepared by the above method is in the form of a sheet with a diameter of 15-25 nm. The nanosheet of this size is beneficial to exposing more active sites, and the sheet structure is beneficial to the transmission of protons and electrons during the reaction, thereby improving the catalytic activity.

[0051] The platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst prepared in the present application has the following two significant features. First, it is encapsulated by a nano-sheet structure, a relatively regular and uniform nanocrystal with a high specific surface area, and there is a mutual synergistic mechanism between the Pt, Ni, Mo, etc. active sites in multiple directions. The second significant feature is the five-element alloy nanostructure, and the d-electron orbitals of the elements interact with each other, thereby achieving a hydrogen evolution performance that exceeds that of the current commercial platinum-carbon. In summary, the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst assembled by nanosheets prepared in the present application has the following advantages: the material has sufficient active sites, good structural stability, strong d-electron interaction, and high catalytic activity.

[0052] Example 1

[0053] A method for preparing a platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystal catalyst assembled by nanosheets, the operation steps are as follows:

[0054] (1) According to the molar ratio of acetylacetone metal salt metal 1:1:1:5.52, 10 mg of acetylacetone platinum (II), 7.69 mg of diacetylacetone palladium (II), 10.1 mg of triacetylacetone rhodium (III), 50 mg of acetylacetone nickel, 50 mg of hexacarbonylmolybdenum, 600 mg of surfactant benzyltriethylammonium chloride, and 7 ml of triethylene glycol are added to a 25 ml beaker, and the mixture is stirred uniformly by magnetic stirring.

[0055] (ii) Add 3 ml of glucose-triethylene glycol solution (containing 60 mg of glucose) to the above solution and mix thoroughly by magnetic stirring.

[0056] (iii) Transfer the solution into a 100 ml round-bottom flask and react in an oil bath at 230 ºC for 1 h.

[0057] (iv) Allow the reaction to cool to room temperature in an oil bath, centrifuge the resulting solution, wash five times with anhydrous ethanol, and dry to obtain the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst assembled from nanosheets. The test results of the obtained platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst are as follows: Figure 1 and Figure 2 As shown. From Figure 2 As can be seen, this is a monolithic nanocrystalline structure. Dark-field TEM provides a more direct view, revealing that this nanocrystal is assembled from nanosheets of 20 nm in size. Furthermore, corresponding energy dispersive spectroscopy analysis shows that platinum, nickel, molybdenum, palladium, and rhodium are uniformly dispersed. The elemental distribution results in the atomic ratios of Pt / Ni / Mo / Pd / Rh of 26.51 / 16.22 / 5.32 / 28.62 / 23.33.

[0058] Example 2

[0059] A method for preparing a platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst assembled from nanosheets, comprising the following steps:

[0060] (a) According to the metal molar ratio of acetylacetone metal salts of 1:1:1:1.1, 10 mg of platinum acetylacetone (II), 7.69 mg of palladium diacetylacetone (II), 10.1 mg of rhodium triacetylacetone (III), 10 mg of nickel acetylacetone, 50 mg of molybdenum hexacarbonyl, 600 mg of surfactant benzyltriethylammonium chloride, and 7 ml of triethylene glycol were added to a 25 ml beaker and mixed evenly by magnetic stirring.

[0061] (ii) Add 3 ml of glucose-triethylene glycol solution (containing 60 mg of glucose) to the above solution and mix thoroughly by magnetic stirring.

[0062] (iii) Transfer the solution into a 100 ml round-bottom flask and react in an oil bath at 230 ºC for 1 h.

[0063] (iv) The reaction was cooled to room temperature in an oil bath. The resulting solution was centrifuged, washed five times with anhydrous ethanol, and dried to obtain the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst assembled from nanosheets. The obtained platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst was obtained from... Figure 3It can be seen that this nanocrystal is assembled from nanosheets with a size of 20 nm. Furthermore, the corresponding energy dispersive spectroscopy analysis shows that platinum, nickel, molybdenum, palladium, and rhodium are uniformly dispersed. The elemental distribution results show that the atomic ratios of Pt / Ni / Mo / Pd / Rh are 24.32 / 6.25 / 6.78 / 25.12 / 37.53.

[0064] Example 3

[0065] A method for preparing a platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst assembled from nanosheets, comprising the following steps:

[0066] (a) According to the metal molar ratio of acetylacetone metal salts of 1:1:1:3.31, 10 mg of platinum acetylacetone (II), 7.69 mg of palladium diacetylacetone (II), 10.1 mg of rhodium triacetylacetone (III), 30 mg of nickel acetylacetone, 50 mg of molybdenum hexacarbonyl, 600 mg of surfactant benzyltriethylammonium chloride, and 7 ml of triethylene glycol were added to a 25 ml beaker and mixed evenly by magnetic stirring.

[0067] (ii) Add 3 ml of glucose-triethylene glycol solution (containing 60 mg of glucose) to the above solution and mix thoroughly by magnetic stirring.

[0068] (iii) Transfer the solution into a 100 ml round-bottom flask and react in an oil bath at 230 ºC for 1 h.

[0069] (iv) Allow the reaction to cool to room temperature in an oil bath, centrifuge the resulting solution, wash five times with anhydrous ethanol, and dry to obtain the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst assembled from nanosheets. The test results of the obtained platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst are as follows: Figure 4 As shown, this nanocrystal is assembled from nanosheets with a size of 20 nm. Furthermore, energy dispersive spectroscopy analysis reveals that platinum, nickel, molybdenum, palladium, and rhodium are uniformly dispersed. The elemental distribution shows that the atomic ratios of Pt / Ni / Mo / Pd / Rh are 35.51 / 10.82 / 6.54 / 30.25 / 16.88.

[0070] Example 4

[0071] A method for preparing a platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst assembled from nanosheets, comprising the following steps:

[0072] (One) 10 mg acetylacetone platinum (II), 7.69 mg diacetylacetone palladium (II), 10.1 mg triacetylacetone rhodium (III), 70 mg acetylacetone nickel, 50 mg hexacarbonylmolybdenum, 600 mg surfactant benzyl triethyl ammonium chloride, 7 ml triethylene glycol are added into a 25 ml beaker in the proportion of 1:1:1:4.58 of the metal molar ratio in acetylacetone metal salt, and magnetically stirred and mixed uniformly.

[0073] (Two) 3 ml of glucose-triethylene glycol solution (containing 60 mg of glucose) is added to the above solution, and magnetically stirred and mixed uniformly.

[0074] (Three) The solution is moved into a 100 ml round bottom flask, and reacted at 230 °C in an oil bath for 1 h.

[0075] (Four) The reaction is allowed to cool to room temperature in an oil bath, and the resulting solution is centrifuged and washed with anhydrous ethanol 5 times, and dried to obtain a nanosheet-assembled platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst. The detection results of the obtained nanosheet-assembled platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst are shown in Figure 5 , which is assembled by 20 nm-sized nanosheets. Secondly, through corresponding energy spectrum analysis, it can be seen that platinum, nickel, molybdenum, palladium and rhodium are uniformly dispersed. The element distribution results are Pt / Ni / Mo / Pd / Rh atomic ratio of 18.82 / 41.28 / 6.59 / 22.12 / 11.19.

[0076] Example 5

[0077] A method for preparing a nanosheet-assembled platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst, the operation steps are as follows:

[0078] (One) 10 mg acetylacetone platinum (II), 7.69 mg diacetylacetone palladium (II), 10.1 mg triacetylacetone rhodium (III), 70 mg acetylacetone nickel, 50 mg hexacarbonylmolybdenum, 600 mg surfactant benzyl triethyl ammonium chloride, 7 ml triethylene glycol are added into a 25 ml beaker in the proportion of 1:1:1:4.58 of the metal molar ratio in acetylacetone metal salt, and magnetically stirred and mixed uniformly.

[0079] (Two) 3 ml of glucose-triethylene glycol solution (containing 60 mg of glucose) is added to the above solution, and magnetically stirred and mixed uniformly.

[0080] (Three) The solution is moved into a 100 ml round bottom flask, and reacted at 230 °C in an oil bath for 1 h.

[0081] (iv) Allow the reaction to cool to room temperature in an oil bath, centrifuge the resulting solution, wash five times with anhydrous ethanol, and dry to obtain the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst assembled from nanosheets. The obtained platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst assembled from nanosheets is as follows: Figure 6 As shown, this high-entropy alloy nanocrystal is assembled from nanosheets.

[0082] Specific applications:

[0083] A three-electrode system was used, with the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst assembled from nanosheets in Example 1 as the working electrode. A reversible hydrogen electrode (RHE) and a graphite rod electrode were used as the reference and counter electrodes, respectively. The electrolyte was 1 M KOH. The test environment was room temperature, and nitrogen gas was saturated during the test.

[0084] (1) The platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst assembled from the nanosheets prepared in Example 1 was mixed with commercial carbon powder in equal mass ratio. After mixing evenly, the mixture was dried to obtain PtNiMoPdRh / C catalyst. 3 mg of PtNiMoPdRh / C catalyst was weighed into a glass sample bottle, and 2 ml of mixed solution (1500 µl anhydrous ethanol, 480 µl ultrapure water and 20 µl 5wt% perfluorosulfonic acid solution) was added. The mixture was then sonicated for 30 min to obtain black mixed solution A. Similarly, 3 mg of commercial platinum carbon catalyst was weighed into a glass sample bottle, and 2 ml of mixed solution (1500 µl anhydrous ethanol, 480 µl ultrapure water and 20 µl 5wt% perfluorosulfonic acid solution) was added. The mixture was then sonicated for 30 min to obtain black mixed solution B.

[0085] (2) Take 8 µl of the black mixture A and B obtained in step (1) and drop them onto different platinum carbon electrodes. After the black mixture A and B stand at room temperature for 30 min, connect them to the electrochemical workstation as working electrodes, and connect the circuit of the counter electrode and the reference electrode. Add the three electrodes to the electrolyte saturated with nitrogen gas.

[0086] (3) Introduce nitrogen gas, set the test parameters, and activate the electrode within a potential range of 0.05 V to -0.4 V. After stabilization, the polarization curve can be obtained by testing the working electrode at 1600 rpm in a nitrogen-saturated electrolyte. Figure 7 ,from Figure 7 As can be seen from a, based on its electrochemical performance, under alkaline conditions, its hydrogen evolution performance is superior to that of commercial platinum-carbon. Specifically, it exhibits performance at a current density of -10 mA cm⁻¹. -2 It has an extremely low overpotential.

[0087] Figure 7b is the electrochemical performance numerical value of the platinum nickel molybdenum palladium rhodium high-entropy alloy nanocrystal catalyst assembled by the nanosheets prepared in Example 1 and the commercial platinum carbon catalyst under 1 M KOH condition, the platinum nickel molybdenum palladium rhodium high-entropy alloy nanocrystal is -10 mA cm -2 The required overpotential is only 9.7 mV, while the commercial platinum carbon requires 70.6 mV to reach the same current density, which shows that the hydrogen evolution reaction is greatly accelerated in the water electrolysis for hydrogen production, and a low energy barrier is achieved to produce high hydrogen.

[0088] In the description of the present application, it should be noted that the terms "upper", "lower", and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. Unless otherwise expressly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0089] It should be noted that in the present application, relational terms such as "first" and "second" and the like are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the sentence "including a" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0090] The above is only a specific embodiment of the present application, which enables those skilled in the art to understand or implement the present application. Various modifications of these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. A method for preparing a platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst, characterized in that, It includes the following steps: Take a surfactant, molybdenum hexacarbonyl and the corresponding metal salts of platinum, nickel, palladium and rhodium, dissolve them in a solvent to obtain a first mixture. The molar ratio of the metal salts corresponding to platinum, palladium, rhodium and nickel is 1:1:1:5.

52. The surfactant is benzyltriethylammonium chloride. The amount of surfactant added is the mass ratio of platinum metal salt to surfactant of 1:

60. A reducing agent is added to the first mixture and stirred to obtain a second mixture. The reducing agent is glucose, and the mass ratio of the reducing agent to the metal salt of platinum is 1:

6. The second mixture was heated and then centrifuged to obtain a platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst. The nanocrystalline catalyst was in the form of sheets with a diameter of 15-25 nm.

2. The preparation method of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst as described in claim 1, characterized in that: The metal salts corresponding to platinum, palladium, and rhodium are platinum acetylacetonate, palladium acetylacetonate, and rhodium acetylacetonate, respectively, while the metal salts corresponding to nickel are nickel acetylacetonate, nickel acetate, or nickel chloride. And / or, the solvent is triethylene glycol.

3. The preparation method of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst as described in claim 1, characterized in that: The glucose is dissolved in the solvent and then added to the first mixture.

4. The preparation method of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst as described in claim 3, characterized in that: The total amount of solvent used in the first mixture and the solvent used for glucose is 10-15 ml.

5. The preparation method of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst as described in claim 1, characterized in that: The heating temperature is 230~240℃, and the heating time is 1~1.5h.

6. The preparation method of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst as described in claim 1, characterized in that: Heating is performed using an oil bath.

7. A platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst, characterized in that: It is prepared using the preparation method of platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst as described in any one of claims 1 to 6.

8. The application of the platinum-nickel-molybdenum-palladium-rhodium high-entropy alloy nanocrystalline catalyst as described in claim 7 in the electrochemical hydrogen evolution reaction.

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