Preparation method of high-entropy alloy hydrogen evolution catalytic material with Pt-rich shell structure

Abstract

The invention discloses a preparation method of a high-entropy alloy hydrogen evolution catalytic material with a Pt-rich shell structure, which comprises the following steps: step 1, performing primary carbon thermal shock on a non-noble metal alloy nanoparticle precursor growing on carbon paper: dropwise adding a precursor solution on carbon fibers, and drying under the irradiation of an infrared lamp to obtain a carbon fiber precursor; carrying out primary carbon thermal shock through a Joule heating furnace, and introducing argon for protection in the carbon thermal shock process, so as to obtain a non-noble metal alloy nanoparticle precursor loaded on carbon fibers; and 2, secondary carbon thermal shock: dropwise adding a chloroplatinic acid solution on the non-noble metal alloy nanoparticle precursor, and carrying out secondary carbon thermal shock to obtain the high-entropy alloy hydrogen evolution catalytic material with the Pt-rich shell structure. The utilization rate of Pt metal on the surface of the high-entropy alloy can be increased, and the catalytic activity of the catalyst is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen evolution catalytic material production, and in particular to a method for preparing a high entropy alloy hydrogen evolution catalytic material with a Pt-rich shell structure. Background Art

[0002] Renewable energy-driven water electrolysis is one of the most promising methods for generating green hydrogen energy and has attracted widespread attention due to its high energy density and abundant resources. However, the slow kinetics of water electrolysis limit its large-scale application. Therefore, highly active and durable catalysts are needed to increase the chemical reaction rate and reduce energy loss. Pt-based materials are considered to be the best electrocatalysts for the hydrogen evolution reaction (HER) due to their high catalytic activity and good stability in alkaline solutions. However, their high cost and scarcity hinder their widespread application. Therefore, the introduction of non-precious metals to alloy with Pt metal would be a feasible strategy. The sufficient incorporation of non-precious metals into the Pt matrix significantly reduces the cost of the catalyst while maintaining or even improving the intrinsic activity of the alloy catalyst.

[0003] High-entropy alloys (HEAs) are single-phase solid solutions composed of multiple elements. Their complex atomic configuration provides a tunable structure. Compared to pure metals or conventional alloys, HEAs offer a more flexible compositional range and synergistic effects. Their random atomic arrangement facilitates electronic structure adjustment, shifting the d-band center of active sites and enhancing catalytic performance. Furthermore, the inherent high entropy effect and delayed diffusion effect of HEAs ensure excellent catalyst stability.

[0004] Carbothermal shock is a non-equilibrium technique that achieves rapid heating and cooling in a short period of time. Its rapid heating / cooling rates and high reaction temperatures effectively promote the homogeneous mixing of virtually any metal, making it a significant advantage in the preparation of catalysts. However, research on high-entropy alloys (HEAs) using carbothermal shock has primarily focused on elemental composition and nanoscale size, resulting in the majority of the precious metal being concentrated within the HEA nanoparticles. This reduces the utilization of the precious metal atoms and significantly diminishes the HEA's catalytic activity.

[0005] CN 117966191 A discloses a high entropy alloy catalytic material for hydrogen evolution by electrolysis of water and a preparation method thereof. The catalytic material comprises a conductive base material and a high entropy alloy film deposited on the surface of the conductive base material; the high entropy alloy film has a chemical formula of (FeCoNiCr) in terms of the molar percentage of each atom. 100-x Pt x, where 10≤x≤40. The preparation method comprises: weighing iron, cobalt, nickel, chromium, and platinum raw materials according to their atomic percentages, and preparing a master alloy ingot using vacuum arc melting. Using the master alloy ingot as a target, a high-entropy alloy thin film is deposited on a substrate using pulsed laser deposition, followed by electrochemical treatment. This method utilizes pulsed laser deposition, which randomly distributes the elements in the high-entropy alloy catalytic material. This results in the majority of the precious metals being located within the high-entropy alloy nanoparticles, reducing the utilization of the precious metal atoms and significantly diminishing the catalytic activity of the high-entropy alloy. Summary of the Invention

[0006] The present invention aims to provide a method for preparing a high-entropy alloy hydrogen evolution catalyst with a Pt-rich shell structure, which can improve the utilization rate of Pt metal on the surface of the high-entropy alloy and enhance the catalytic activity of the catalyst. Furthermore, the stability of the high-entropy alloy core and the interaction between the core and shell improve the stability of the catalyst.

[0007] The technical solution adopted by the present invention to solve its technical problem is: A method for preparing a high entropy alloy hydrogen evolution catalytic material having a Pt-rich shell structure, comprising the following steps: Step 1: Single carbon thermal shock growth of non-precious metal alloy nanoparticle precursors on carbon paper: mixing ferric chloride hexahydrate, cobalt chloride hexahydrate, nickel chloride hexahydrate, and chromium chloride hexahydrate with ethanol to form ferric chloride hexahydrate alcohol solution, cobalt chloride hexahydrate alcohol solution, nickel chloride hexahydrate alcohol solution, and chromium chloride hexahydrate alcohol solution, respectively, and mixing the alcohol solutions to form a precursor solution; The precursor solution is dropped onto the carbon fiber, dried under infrared light, and subjected to a carbon thermal shock in a Joule heating furnace. Argon gas is introduced during the carbon thermal shock process to obtain a non-precious metal alloy nanoparticle precursor supported on the carbon fiber; Step 2: Secondary carbon thermal shock: Chloroplatinic acid solution is added dropwise onto the non-precious metal alloy nanoparticle precursor to perform a secondary carbon thermal shock. Argon gas is introduced during the carbon thermal shock process to allow the Pt element to be secondary loaded with the non-precious metal alloy nanoparticle precursor, thereby regulating the distribution of Pt metal on the surface and ultimately obtaining a high-entropy alloy hydrogen evolution catalytic material with a Pt-rich shell structure.

[0008] The present invention uses carbon thermal shock to prepare a high-entropy alloy catalytic material, which has a high reaction temperature and a short reaction time. It also avoids excessive oxidation caused by prolonged heating, ensuring that the material exists in the form of an alloy. The second carbon thermal shock is performed for a shorter time than the first.

[0009] The Pt-rich shell is obtained by shortening the carbon thermal shock time. The catalytic material prepared by this invention exhibits superior catalytic activity and stability primarily because, compared to conventional high-entropy alloys, this invention utilizes a secondary carbon thermal shock to form a Pt-rich shell on the surface of the high-entropy alloy, increasing the utilization of Pt atoms and accelerating water decomposition. Furthermore, the stability of the high-entropy alloy core and the interaction between the core and shell enhance the stability of the catalyst.

[0010] The current of the two carbon thermal shocks of the present invention is the same, ensuring that the temperature reached by the two carbon thermal shocks is the same, which is conducive to the secondary loading of the Pt element and the non-precious metal alloy nanoparticles, so that more Pt elements are exposed outside the non-precious metal alloy nanoparticles, forming a high-entropy alloy hydrogen evolution catalytic material with a Pt-rich shell structure.

[0011] The present invention uses carbon paper as the substrate because the carbon fiber surface can load more nanoparticles and has better conductivity, which is beneficial to the subsequent catalytic reaction.

[0012] Preferably, the molar ratio of ferric chloride hexahydrate: cobaltous chloride hexahydrate: nickel chloride hexahydrate: chromium chloride hexahydrate: chloroplatinic acid is 1:1:1:1:1.

[0013] Preferably, in step 1, the conditions for a single carbon thermal shock are: a carbon thermal shock current of 30-40A and a carbon thermal shock duration of 1-2 seconds. The thermal shock current primarily controls the temperature at which the high-entropy alloy is formed. A low temperature prevents the high-entropy alloy from forming a single-phase structure. Higher currents and temperatures have no effect on the high-entropy alloy, but may actually degrade its performance. Therefore, selecting the optimal current ensures both the formation of a high-entropy alloy and optimal performance.

[0014] Preferably, the temperature change process of a carbon thermal shock is divided into three stages: the first stage is heating: from room temperature to 2200±100℃, with a heating rate of 3500-4000℃ / s; the second stage is heat preservation: keeping at 2200±100℃ for 0.6-1 second; the third stage is cooling: cooling down to room temperature at a cooling rate of 2000-2200℃ / s.

[0015] Preferably, the concentrations of the ferric chloride hexahydrate alcohol solution, the cobalt chloride hexahydrate alcohol solution, the nickel chloride hexahydrate alcohol solution, and the chromium chloride hexahydrate alcohol solution are all 0.1-0.2 mmol / mL.

[0016] Preferably, the concentration of the chloroplatinic acid solution is 0.1-0.2 mmol / mL.

[0017] Preferably, in step 2, the secondary carbon thermal shock current is 30-40A, and the carbon thermal shock time is half of the primary carbon thermal shock time.

[0018] Preferably, the temperature change process of the secondary carbon thermal shock is divided into three stages: the first stage is heating: from room temperature to 2200±100℃, with a heating rate of 7000-8000℃ / s; the second stage is heat preservation: keeping at 2200±100℃ for 0.2-0.4 seconds; the third stage is cooling: cooling to room temperature at a cooling rate of 10000-11000℃ / s.

[0019] The beneficial effects of the present invention are: 1. The high entropy alloy hydrogen evolution catalytic material with a Pt-rich shell structure prepared by the present invention can reach 10 mA / cm in the hydrogen evolution reaction (HER) process with an overpotential of only 51 mV in 1M KOH alkaline medium. 2 At a current density of 100 mA / cm 2 In the stability test of continuous discharge at a current density of 100 h, the overpotential dropped by only 8%, indicating good stability.

[0020] 2. The raw materials of the present invention are selected from non-precious metals as the core and precious metals as the core-shell, which not only reduces the cost of precious metals but also utilizes the synergistic effect of the metals to enhance the catalytic activity of the catalytic material. By shortening the carbon thermal shock time, the distribution of precious metals on the surface of high-entropy alloy nanoparticles is improved, reducing the probability of precious metals entering the inner core, and exposing more catalytically active sites. Thus, the hydrogen evolution catalytic material prepared by the present invention has great application potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is an X-ray diffraction (XRD) test spectrum of the high entropy alloy hydrogen evolution catalytic material with a Pt-rich shell structure prepared by the present invention.

[0022] Figure 2 This is a scanning electron microscope (SEM) image of the high entropy alloy hydrogen evolution catalytic material with a Pt-rich shell structure prepared by the present invention; Figure 2 a and Figure 2 b is the scanning electron microscopy image at different magnifications.

[0023] Figure 3 This is a high-angle annular dark field scanning transmission electron microscope (HAADF-STEM) image of a high-entropy alloy hydrogen evolution catalytic material with a Pt-rich shell structure prepared by the present invention; Figure 3 a Low resolution transmission and Figure 3 b is high-resolution transmission.

[0024] Figure 4 is a line scan of a high entropy alloy hydrogen evolution catalytic material having a Pt-rich shell structure prepared by the present invention; wherein Figure 4 a is a line scan image, Figure 4 b is the result graph.

[0025] Figure 5 The LSV comparison curve and stability test curve corresponding to HER in 1 M KOH alkaline environment of the high entropy alloy hydrogen evolution catalytic material with a Pt-rich shell structure prepared by the present invention are shown in FIG. Figure 5 a is the hydrogen evolution catalytic performance diagram, Figure 5 b is the hydrogen evolution performance diagram of different Pt-based catalytic materials, Figure 5 c is the stability test diagram of different Pt-based catalytic materials.

[0026] Figure 6 This is a carbon thermal shock temperature change curve of the high entropy alloy hydrogen evolution catalytic material with a Pt-rich shell structure prepared in Example 1.

[0027] Figure 7 3 is a comparison chart of the hydrogen evolution catalytic performance of the material prepared in Example 1 and the material prepared in Comparative Example 5; wherein Pt / FeCoNiCr is Example 1, and Pt2 / FeCoNiCr is Comparative Example 5. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further described in detail below through specific embodiments.

[0029] In the present invention, unless otherwise specified, the raw materials and equipment used can be purchased from the market or are commonly used in the art. The methods in the following examples, unless otherwise specified, are all conventional methods in the art.

[0030] Ferric chloride hexahydrate, nickel chloride hexahydrate, and chromium chloride hexahydrate were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; cobalt chloride hexahydrate was purchased from Shanghai MacLean Biotechnology Co., Ltd.; chloroplatinic acid was purchased from Leyan Technology Co., Ltd.; and carbon paper was purchased from Taiwan Carbon Energy Technology Co., Ltd.

[0031] Example 1: The first step is to mix 30uL of 0.15mmol / ml ferric chloride hexahydrate alcohol solution (alcohol is anhydrous ethanol, the same below), 30uL of 0.15mmol / ml cobalt chloride hexahydrate alcohol solution, 30uL of 0.15mmol / ml nickel chloride hexahydrate alcohol solution, and 30uL of 0.15mmol / ml chromium chloride hexahydrate alcohol solution, and drop them on carbon paper (1cm×4cm). Ensure that the ethanol is completely evaporated under infrared lamp irradiation. Then place it in a Joule heating furnace for a carbon thermal shock. Argon is introduced as a protective gas during the carbon thermal shock process. The carbon thermal shock current is 30A, the carbon thermal shock time is 2S, and the temperature change of one carbon thermal shock is shown in FIG. Figure 6 (thermal shock temperature 2200°C), thereby obtaining a non-noble metal alloy nanoparticle precursor supported on carbon fiber.

[0032] In the second step, 30 μL of a 0.15 mmol / ml chloroplatinic acid alcohol solution was added dropwise onto the carbon paper containing the non-precious metal alloy nanoparticle precursor. The ethanol was completely evaporated by infrared light irradiation. The paper was then placed in a Joule heating furnace for a secondary carbon thermal shock. Argon was introduced as a protective gas during the carbon thermal shock process. The secondary carbon thermal shock current was 30 A, the secondary carbon thermal shock time was 1 s, and the secondary carbon thermal shock temperature change was shown in Figure 2. Figure 6 (Thermal shock temperature 2200℃).

[0033] Comparative Example 1: Mix 30uL of 0.15mmol / ml ferric chloride hexahydrate alcohol solution, 30uL of 0.15mmol / ml cobalt chloride hexahydrate alcohol solution, 30uL of 0.15mmol / ml nickel chloride hexahydrate alcohol solution, 30uL of 0.15mmol / ml chromium chloride hexahydrate alcohol solution, and 30uL of 0.15mmol / ml chloroplatinic acid alcohol solution, and drop them onto carbon paper (1cm×4cm). Ensure that the ethanol is completely evaporated under infrared lamp irradiation. Then place it in a Joule heating furnace for a carbon thermal shock. Argon is introduced as a protective gas during the carbon thermal shock process. The carbon thermal shock current is 30A, the carbon thermal shock time is 2S, and the temperature change of one carbon thermal shock is shown in FIG. Figure 6 (thermal shock temperature 2200℃), thus obtaining a single thermal shock high entropy alloy nanoparticle catalytic material supported on carbon fiber.

[0034] Comparative Example 2: Mix 30uL of 0.15mmol / ml ferric chloride hexahydrate alcohol solution, 30uL of 0.15mmol / ml cobalt chloride hexahydrate alcohol solution, 30uL of 0.15mmol / ml nickel chloride hexahydrate alcohol solution, and 30uL of 0.15mmol / ml chromium chloride hexahydrate alcohol solution evenly, drop them onto carbon paper (1cm×4cm), and ensure that the ethanol is completely evaporated under infrared light. Then place it in a Joule heating furnace for a carbon thermal shock. Argon is introduced as a protective gas during the carbon thermal shock process. The carbon thermal shock current is 30A, the carbon thermal shock time is 1S, and the temperature change of one carbon thermal shock is shown in FIG. Figure 6 (thermal shock temperature 2200°C), thereby obtaining a non-noble metal alloy nanoparticle precursor supported on carbon fiber.

[0035] Comparative Example 3: Pipette 30 μL of 0.15mmol / ml chloroplatinic acid alcohol solution and drop it onto carbon paper. Ensure that the ethanol is completely evaporated under infrared light. Then place it in a Joule heating furnace for a carbon thermal shock. During the carbon thermal shock, argon is introduced as a protective gas. The carbon thermal shock current is 30A and the carbon thermal shock time is 1s. The temperature change of one carbon thermal shock is shown in Figure 2. Figure 6 (Thermal shock temperature 2200℃).

[0036] Comparative Example 4: Pipette 150 μL of a 0.15 mmol / ml chloroplatinic acid alcohol solution (the same total molar amount as the high-entropy alloy + Pt in Example 1) and drip it onto carbon paper. Ensure complete evaporation of the ethanol under infrared light. Then place it in a Joule heating device for a single carbon thermal shock, using argon as a protective gas. The carbon thermal shock current is 30 A, the carbon thermal shock time is 2 s, and the temperature change after one carbon thermal shock is shown in Figure 2. Figure 6 (Thermal shock temperature 2200℃).

[0037] Example 2: The first step involves mixing 30 μL of a 0.1 mmol / mL ferric chloride hexahydrate alcohol solution (the alcohol is anhydrous ethanol, the same below), 30 μL of a 0.1 mmol / mL cobalt chloride hexahydrate alcohol solution, 30 μL of a 0.1 mmol / mL nickel chloride hexahydrate alcohol solution, and 30 μL of a 0.1 mmol / mL chromium chloride hexahydrate alcohol solution. The mixture is then dropped onto a 1 cm × 4 cm carbon paper sheet. Irradiation with an infrared lamp ensures complete evaporation of the ethanol. The sheet is then placed in a Joule heating furnace for a carbon shock cycle, with argon as the protective gas. The carbon thermal shock current is 30A, the carbon thermal shock time is 2S, and the carbon thermal shock temperature is 2200℃ (the first stage of heating: from room temperature to 2200℃, the heating rate is 3500℃ / s; the second stage of keeping warm: keeping warm at 2200℃ for 1 second; the third stage of cooling: cooling down to room temperature at a cooling rate of 2000℃ / s), thereby obtaining a non-precious metal alloy nanoparticle precursor loaded on carbon fiber.

[0038] In the second step, 30 μL of a 0.1 mmol / mL chloroplatinic acid-alcohol solution was pipetted onto the carbon paper containing the non-precious metal alloy nanoparticle precursor. The ethanol was completely evaporated by infrared irradiation. The paper was then placed in a Joule furnace for a secondary carbon thermal shock, with argon as a protective gas. The secondary carbon thermal shock current was 30 A, the duration was 1 second, and the temperature was 2200°C. (The first stage involved heating from room temperature to 2200°C at a rate of 7000°C / s; the second stage involved holding at 2200°C for 0.4 seconds; and the third stage involved cooling to room temperature at a rate of 10,000°C / s.)

[0039] Example 3: The first step is to mix 30 μL of a 0.2 mmol / mL ferric chloride hexahydrate alcohol solution (the alcohol is anhydrous ethanol, the same below), 30 μL of a 0.2 mmol / mL cobalt chloride hexahydrate alcohol solution, 30 μL of a 0.2 mmol / mL nickel chloride hexahydrate alcohol solution, and 30 μL of a 0.2 mmol / mL chromium chloride hexahydrate alcohol solution. The mixture is then dropped onto a 1 cm × 4 cm carbon paper sheet. Irradiation with an infrared lamp ensures complete evaporation of the ethanol. The sheet is then placed in a Joule heating furnace for a carbon shock cycle, with argon as the protective gas. The carbon thermal shock current is 40A, the carbon thermal shock time is 1S, and the carbon thermal shock temperature is 2300℃ (the first stage of heating: from room temperature to 2300℃, the heating rate is 4000℃ / s; the second stage of keeping warm: keeping warm at 2300℃ for 0.6 seconds; the third stage of cooling: cooling down to room temperature at a cooling rate of 2200℃ / s), thereby obtaining a non-precious metal alloy nanoparticle precursor loaded on carbon fiber.

[0040] In the second step, 30 μL of a 0.2 mmol / mL chloroplatinic acid-alcohol solution was pipetted onto the carbon paper containing the non-precious metal alloy nanoparticle precursor. The ethanol was completely evaporated by infrared irradiation. The paper was then placed in a Joule furnace for a secondary carbon thermal shock, with argon as a protective gas. The secondary carbon thermal shock current was 40 A, the secondary carbon thermal shock duration was 0.5 s, and the secondary carbon thermal shock temperature was 2300°C. (The first stage involved heating from room temperature to 2300°C at a rate of 8000°C / s; the second stage involved holding at 2300°C for 0.2 seconds; and the third stage involved cooling to room temperature at a rate of 11000°C / s.)

[0041] Comparative Example 5: The first step is to mix 30uL of 0.15mmol / ml ferric chloride hexahydrate alcohol solution (the alcohol is anhydrous ethanol), 30uL of 0.15mmol / ml cobalt chloride hexahydrate alcohol solution, 30uL of 0.15mmol / ml nickel chloride hexahydrate alcohol solution, and 30uL of 0.15mmol / ml chromium chloride hexahydrate alcohol solution evenly, and drop it on carbon paper (1cm×4cm). Ensure that the ethanol is completely evaporated under infrared lamp irradiation. Then place it in a Joule heating furnace for a carbon thermal shock. Argon is introduced as a protective gas during the carbon thermal shock process. The carbon thermal shock current is 30A, the carbon thermal shock time is 2S, and the temperature change of one carbon thermal shock is shown in FIG. Figure 6 (thermal shock temperature 2200°C), thereby obtaining a non-precious metal alloy nanoparticle precursor supported on carbon fiber.

[0042] In the second step, 30 μL of a 0.15 mmol / ml chloroplatinic acid alcohol solution was added dropwise onto the carbon paper containing the non-precious metal alloy nanoparticle precursor. The ethanol was completely evaporated by infrared light irradiation. The paper was then placed in a Joule heating furnace for a secondary carbon thermal shock. Argon was introduced as a protective gas during the carbon thermal shock process. The secondary carbon thermal shock current was 30 A, the secondary carbon thermal shock time was 2 s, and the secondary carbon thermal shock temperature change was shown in Figure 2. Figure 6 (thermal shock temperature 2200℃), thus obtaining a high-entropy alloy catalytic material with two thermal shock times of 2S.

[0043] Figure 1 This is an X-ray diffraction (XRD) test pattern of the catalytic material prepared in Example 1 of the present invention.

[0044] Figure 2 This is a scanning electron microscope (SEM) characterization image of the catalytic material prepared in Example 1 of the present invention. It can be seen from the image that high entropy alloy nanoparticles are evenly distributed on the carbon fiber without obvious agglomeration.

[0045] Figure 3 This is a high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) characterization image of the catalytic material prepared in Example 1 of the present invention, showing that the five metal elements Pt, Fe, Co, Ni and Cr are evenly distributed without phase separation.

[0046] Figure 4 This is a line scan of the catalytic material prepared in Example 1 of the present invention. The Pt element is primarily distributed on the outside, while the signals of Fe, Co, Ni, and Cr are distributed on the inside. The intensity of Pt is much higher than that of the other four elements, confirming the formation of a high-entropy alloy catalytic material with a Pt-rich shell structure.

[0047] Figure 5 This is the LSV curve diagram and stability test curve of the hydrogen evolution reaction (HER) of the catalytic material prepared in Example 1 of the present invention in an alkaline electrolyte (1 M KOH). It can be concluded that the catalytic material has excellent catalytic activity and stability in an alkaline environment. Figure 5 In Figure a, Pt@FeCoNiCr is the catalyst material prepared in Example 1. A high-entropy alloy hydrogen evolution catalyst with a Pt-rich shell structure was prepared using a double carbon thermal shock technique. FeCoNiCrPt is the catalyst material prepared in Comparative Example 1. The catalytic performance of the catalyst prepared using only a single carbon thermal shock technique is significantly reduced compared to using a double carbon thermal shock technique. FeCoNiCr is the non-precious metal alloy nanoparticle precursor prepared in Comparative Example 2. Pt / C is commercial Pt / C, purchased.

[0048] Figure 5A comparison of these materials demonstrates that the Pt-rich shell high-entropy alloy catalyst outperforms the FeCoNiCrPt high-entropy alloy catalyst obtained through a single thermal shock, highlighting the role of Pt on the surface. Furthermore, its superior performance over Pt / C demonstrates that the advantages of the high-entropy alloy are leveraged while reducing costs.

[0049] Pt-1 is comparative example 3, Pt-2 is comparative example 4, Figure 5 b The high entropy alloy catalytic material with a Pt-rich shell structure has the best performance compared with different Pt-based catalytic materials. The comparison with Pt-1 mainly shows that the non-precious metal alloy nanoparticle precursor prepared in the first thermal shock process also plays a catalytic role. The comparison with Pt-2 mainly shows that the high entropy alloy has better hydrogen evolution performance than pure Pt.

[0050] Figure 5 c indicates that at 100 mA / cm 2 In the stability test of continuous discharge at a current density of 100 h, the overpotential dropped by only 8%, indicating good stability.

[0051] Pt-based materials are considered to be the best electrocatalysts for HER due to their high catalytic activity and good stability in alkaline solutions. However, by comparison, the catalytic performance of high-entropy alloy hydrogen evolution catalytic materials with a Pt-rich shell structure is far superior to that of different types of Pt-based catalytic materials, indicating that high-entropy alloy hydrogen evolution catalytic materials with a Pt-rich shell structure have broad application prospects.

[0052] like Figure 7 As shown, the second thermal shock time of Comparative Example 5 is 2S, which is beyond the scope of the present invention. It is found that the performance is significantly lower than that of Example 1. This may be because the second thermal shock time is too long, causing more Pt to enter the interior of the high-entropy alloy and reducing the distribution rate of Pt on the surface.

[0053] The embodiment described above is only a preferred solution of the present invention and does not limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solution described in the claims.

Claims

1. A method for preparing a high entropy alloy hydrogen evolution catalytic material having a Pt-rich shell structure, characterized in that: Here are the steps: Step 1: Single carbon thermal shock growth of non-precious metal alloy nanoparticle precursors on carbon paper: mixing ferric chloride hexahydrate, cobalt chloride hexahydrate, nickel chloride hexahydrate, and chromium chloride hexahydrate with ethanol to form ferric chloride hexahydrate alcohol solution, cobalt chloride hexahydrate alcohol solution, nickel chloride hexahydrate alcohol solution, and chromium chloride hexahydrate alcohol solution, respectively, and mixing the alcohol solutions to form a precursor solution; The precursor solution is dropped onto the carbon fiber, dried under infrared light, and subjected to a carbon thermal shock in a Joule heating furnace. Argon gas is introduced during the carbon thermal shock process to obtain a non-precious metal alloy nanoparticle precursor supported on the carbon fiber; Step 2: Secondary carbon thermal shock: Chloroplatinic acid solution is added dropwise onto the non-precious metal alloy nanoparticle precursor to perform a secondary carbon thermal shock. Argon gas is introduced during the carbon thermal shock process to allow the Pt element to be secondary loaded with the non-precious metal alloy nanoparticle precursor, thereby regulating the distribution of Pt metal on the surface and ultimately obtaining a high-entropy alloy hydrogen evolution catalytic material with a Pt-rich shell structure.

2. The preparation method according to claim 1, characterized in that The molar ratio of ferric chloride hexahydrate: cobalt chloride hexahydrate: nickel chloride hexahydrate: chromium chloride hexahydrate: chloroplatinic acid is 1:1:1:1:

1.

3. The preparation method according to claim 1, characterized in that In step 1, the conditions for a carbon thermal shock are: a carbon thermal shock current of 30-40A, and a carbon thermal shock time of 1-2 seconds.

4. The preparation method according to claim 3, characterized in that The temperature change process of a carbon thermal shock is divided into three stages: the first stage is heating: from room temperature to 2200±100℃, with a heating rate of 3500-4000℃ / s; the second stage is keeping warm: keeping warm at 2200±100℃ for 0.6-1 second; the third stage is cooling: cooling down to room temperature at a cooling rate of 2000-2200℃ / s.

5. The preparation method according to claim 1, characterized in that The concentrations of the ferric chloride hexahydrate alcohol solution, the cobalt chloride hexahydrate alcohol solution, the nickel chloride hexahydrate alcohol solution, and the chromium chloride hexahydrate alcohol solution are all 0.1-0.2 mmoL / mL.

6. The preparation method according to claim 1, characterized in that The concentration of the chloroplatinic acid solution is 0.1-0.2 mmol / mL.

7. The preparation method according to claim 1, characterized in that In step 2, the secondary carbon thermal shock current is 30-40A, and the carbon thermal shock time is half of the primary carbon thermal shock time.

8. The preparation method according to claim 7, characterized in that The temperature change process of the secondary carbon thermal shock is divided into three stages: the first stage is heating: from room temperature to 2200±100℃, with a heating rate of 7000-8000℃ / s; the second stage is keeping warm: keeping warm at 2200±100℃ for 0.2-0.4 seconds; the third stage is cooling: cooling down to room temperature at a cooling rate of 10000-11000℃ / s.

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