Method for preparing surface platinum-enriched high-entropy alloy hydrogen evolution electrocatalyst by atomic layer deposition technology

Abstract

The invention discloses a method for preparing a surface platinum-enriched high-entropy alloy hydrogen evolution electrocatalyst by an atomic layer deposition technology. According to the method, controllable deposition and uniform distribution of platinum atoms are realized by utilizing self-limiting reaction of atomic layer deposition. Compared with an existing heat treatment, pulse annealing, wet chemical epitaxy or replacement modification method, the method has the advantages that precise deposition of atomic-scale platinum can be achieved, the problems of high-entropy base surface precious metal agglomeration, non-uniform enrichment, uncontrollable diffusion and the like are solved, and therefore the precious metal utilization efficiency and the surface structure controllability are remarkably improved. Through verification, the surface regulation strategy enables the catalyst to show lower overpotential, faster dynamics and higher quality activity in a hydrogen evolution reaction. According to the technical route, a new method is provided for high-entropy alloy surface engineering, and a new thought is provided for constructing an electro-catalytic material with high activity and high precious metal utilization rate.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electrocatalytic material preparation and surface interface regulation, and particularly relates to a method for preparing a surface platinum-enriched high-entropy alloy hydrogen evolution electrocatalyst by using an atomic layer deposition (ALD) technique. BACKGROUND

[0002] High-entropy alloys (HEAs) have been widely used in electrocatalysis in recent years due to their high configurational entropy, severe lattice distortion, sluggish diffusion effect and synergistic cocktail effect. HEAs have tunable composition and abundant active sites, but traditional preparation methods usually result in single-phase solid solution structures, with the surface composition close to the bulk phase, which leads to the burial of noble metal sites inside the particles, resulting in problems such as insufficient surface active sites, low utilization of noble metals, and limited catalytic efficiency. These problems are particularly prominent in the hydrogen evolution reaction (HER), which is highly sensitive to noble metal loading and reaction intermediate adsorption energy.

[0003] In order to improve the exposure of surface active sites and the utilization efficiency of noble metals of HEAs, various surface engineering strategies have been proposed, including:

[0004] The first method is to achieve surface enrichment by thermal shock / joule heat. For example, Yao et al. [1] A multistep joule heating method is used to prepare a FeCoNiCu noble metal-free HEA core through ultrafast high-temperature shock, and then introduce noble metal precursors in the second short-time heating to achieve the enrichment of Pd elements on the surface of HEA. However, this method relies on non-equilibrium, fast diffusion and annealing kinetics, and is highly sensitive to temperature and time window, which can easily lead to uncontrolled migration of noble metals on the surface, near the surface, and even in the bulk phase, making it difficult to accurately regulate the atomic-level distribution of noble metals. A slight deviation in temperature can cause grain growth, phase separation or excessive agglomeration of noble metal particles.

[0005] The second method is phase precipitation regulation based on pulsed annealing. For example, by applying multi-cycle rapid annealing on the HEA of PdSnFeCoNi, selective precipitation of PdSn ultrafine clusters in the HEA matrix is achieved, and an HEA / c-PdSn heterostructure is constructed [2] This method relies on phase separation induced by enthalpy difference and surface energy difference between different elements. However, this method is difficult to accurately control the size, number and distribution of clusters, and the resulting surface configuration is highly dependent on the chemical composition of the specific alloy system, which has limited universality.

[0006] The third method is epitaxial growth under liquid phase conditions. For example, Yang et al.[3] Pd@HEA structure of Pd core / HEA shell is reported, and a surface controllable structure is constructed by epitaxial growth of several layers of HEA shell on Pd nanocrystalline seeds. Although this method can obtain a HEA shell with a specific thickness, it usually requires a specific crystal face, a specific noble metal core and a multi-step chemical condition, and the preparation window is narrow, which is difficult to adapt to different HEA systems. At the same time, the thickness of the shell layer is difficult to accurately control at the atomic level, which leads to the difficulty of optimizing the synergistic effect of interface strain and electronic coupling.

[0007] The fourth type of method is to realize surface replacement by electrochemistry. For example, Pt is introduced on the surface of FeCoNiCu nanoparticles by displacement reaction, thereby forming a FeCoNiCu@Pt core-shell structure [4] However, such methods usually generate a variety of mixed states such as single atoms, small clusters and surface near-alloy, and the displacement efficiency, noble metal distribution and core-shell boundary configuration are difficult to accurately control. In addition, the displacement reaction is driven by potential difference and is easily affected by solution conditions, and the reproducibility is poor.

[0008] In summary, the existing surface engineering methods of high-entropy alloys generally have the following technical problems: the noble metal surface configuration is difficult to control at the atomic level: thermal diffusion, precipitation or displacement are limited by element diffusion potential and chemical potential, and do not have atomic level accuracy; the noble metal distribution and coverage are uncontrollable: easy to appear clustering, segregation, deep penetration, leading to non-uniform active site configuration; the method is strongly dependent on specific material system, and the universality is insufficient: such as pulse annealing or epitaxial growth is only suitable for specific crystal face or specific metal combination; the preparation process is sensitive to temperature / nucleation conditions, and the repeatability is poor; due to the uncontrollable surface structure, it is not conducive to the study of the structure-activity relationship of the catalyst.

[0009] Therefore, the existing technology still lacks a technical means capable of realizing controllable, atomic-scale noble metal modification on the surface of high-entropy alloys. This is the core technical problem to be solved by the present application. SUMMARY

[0010] The present application provides a method for preparing a surface platinum-rich high-entropy alloy hydrogen evolution electrocatalyst by atomic layer deposition technology, which realizes the preparation of a surface platinum-rich high-entropy alloy hydrogen evolution electrocatalyst by using the self-limiting reaction of atomic layer deposition (ALD) 0.25Controllable deposition and uniform distribution of platinum atoms on the surface of FeCoNiCu HEA. Compared with existing heat treatment, pulse annealing, wet chemical epitaxy or displacement modification methods, this method can achieve precise deposition of atomic platinum, avoiding problems such as high-entropy base surface noble metal aggregation, non-uniform enrichment, and uncontrollable diffusion, thereby significantly improving the utilization efficiency of noble metals and the controllability of the surface structure. It has been verified that the surface regulation strategy makes the catalyst exhibit lower overpotential, faster kinetics, and higher mass activity in the hydrogen evolution reaction (HER). The technical route of the present application provides a new method for high-entropy alloy surface engineering and a new idea for constructing electrocatalytic materials with high activity and high noble metal utilization rate.

[0011] The method for preparing a surface platinum-enriched high-entropy alloy hydrogen evolution electrocatalyst by atomic layer deposition technology of the present application is based on atomic layer deposition technology, and precisely prepares a catalyst with different loadings of platinum-enriched high-entropy alloy on the surface by adjusting the number of platinum deposition cycles, including the following steps:

[0012] Step 1: Mix metal salts, carbon carriers, and sodium borohydride reducing agents in a solvent to grow high-entropy alloy nanoparticles composed of iron, cobalt, nickel, copper, and platinum on the carbon carrier by liquid phase reduction method.

[0013] Step 2: Expose and remove metal platinum precursors and oxidizing agents in sequence by atomic layer deposition technology to achieve controllable deposition of platinum on the surface of high-entropy alloy, thereby obtaining a surface platinum-enriched high-entropy alloy catalyst.

[0014] In step 1, the feeding amount of the metal salt is 0.01-0.1 mmol, the feeding amount of sodium borohydride is 10-50 mmol, the feeding amount of the carbon carrier is 0.1-1 g, and the reaction time is 10-180 min.

[0015] The metal salt includes but is not limited to platinum chloride hexahydrate, iron chloride (or ferric nitrate), cobalt chloride (or cobalt nitrate), nickel chloride (or nickel nitrate), and copper chloride (or copper nitrate). Whether the metal salt contains crystal water does not affect the reaction, and the type of anion also does not constitute a limitation, as long as the metal salt can release the corresponding metal positive ion, which falls within the scope of the raw materials of the present application.

[0016] The carbon carrier (C) includes but is not limited to conductive carbon black (such as Ketjenblack EC-600JD, Vulcan XC-72R, acetylene black), carbon aerogel, mesoporous carbon, nitrogen / oxygen / sulfur heteroporous carbon, graphite phase carbon nitride (g-C3N4), reduced graphene oxide (rGO), graphene, carbon nanotubes (CNTs), carbon nanofibers (CNFs), hollow carbon spheres, carbon-coated materials, and other carbon-based carriers with good electrical conductivity and specific surface area.

[0017] In step 2, the metal platinum precursor used in the present application can be any metal platinum precursor known to those skilled in the art that can be used in atomic layer deposition technology, and there is no special restriction. In the present application, trimethyl(methylcyclopentadienyl) platinum (MeCpPtMe3) is preferred. The oxidizing agent used can be any oxidizing agent known to those skilled in the art, and oxygen is preferred.

[0018] In step 2, the atomic layer deposition sequence is as follows: metal platinum precursor exposure; metal platinum precursor removal (purging with inert gas such as nitrogen, argon, etc.); oxidizing substance exposure; oxidizing substance removal (purging with inert gas such as nitrogen, argon, etc.). The above cycle is one cycle, which can be repeated for multiple cycles. Further, it can be repeated for 1-7 cycles, preferably 3-5 cycles.

[0019] Further preferably, the metal platinum precursor exposure time is 100-500 s, and the metal platinum precursor removal time is 200-600 s; the oxidizing substance exposure time is 300-600 s, and the oxidizing substance removal time is 100-600 s.

[0020] In step 2, the reaction temperature is 120-300℃.

[0021] The surface platinum-enriched high-entropy alloy catalyst comprises a carbon carrier and a surface platinum-enriched high-entropy alloy supported on the carbon carrier.

[0022] In the surface platinum-enriched high-entropy alloy, the elements are platinum, iron, cobalt, nickel and copper. In the surface platinum-enriched high-entropy alloy catalyst, the loading of metal platinum is 1-13 wt%, and the loading of the remaining metals is 1-3 wt%. The element selection and element ratio of the high-entropy alloy according to the present application are not subject to special restrictions, and only need to meet the definition of high-entropy alloy.

[0023] The present application relates to the use of a surface platinum-enriched high-entropy alloy catalyst in an electrocatalytic hydrogen evolution reaction.

[0024] Further, a three-electrode system is used, a graphite electrode is used as the counter electrode, Ag / AgCl is used as the reference electrode, and the surface platinum-enriched high-entropy alloy catalyst is used as the working electrode to perform the electrocatalytic hydrogen evolution reaction.

[0025] The present application utilizes the self-limiting reaction characteristics of the atomic layer deposition process to achieve atomic-level precision platinum modification by adjusting the number of deposition cycles, so that platinum can be highly dispersed and selectively enriched on the surface of the high-entropy alloy, and the activity of the catalyst for the hydrogen evolution reaction (HER) and the utilization efficiency of noble metals are significantly improved.

[0026] The present application adopts atomic layer deposition technology to deposit noble metal platinum on the surface of high-entropy alloy, realizing the atomic level precision modification which is difficult to achieve by traditional methods. The technology relies on the self-limiting reaction characteristics of atomic layer deposition technology, enabling platinum atoms to be uniformly deposited on the surface of HEA in a highly dispersed manner without damaging the multi-metal solid solution structure of HEA, effectively improving the exposure degree and utilization rate of noble metals. The surface enrichment of platinum sites promotes the downward shift of the d-band center, optimizes the hydrogen adsorption energy, and the existence of hydrogen overflow effect speeds up the hydrogen evolution kinetics. In terms of HER performance, 3cPt@HEA only requires an overpotential of 11 mV at 10 mA cm -2 , and the Tafel slope is 19.3 mV dec -1 , which is significantly better than unmodified HEA and commercial 20 wt% Pt / C. In addition, the ALD preparation process is mild and highly repeatable, avoiding problems such as agglomeration and phase separation caused by thermal diffusion, making the catalyst structure stable and controllable.

[0027] In summary, the surface platinum modified high-entropy alloy material constructed by atomic layer deposition technology has the advantages of high noble metal utilization rate, strong hydrogen evolution activity, good structure controllability, and stable and reliable preparation process, effectively solving the technical bottleneck of atomic level regulation of existing high-entropy alloy surface engineering. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 (a) high-resolution TEM image and (b) particle size statistics of high-entropy alloy synthesized by liquid phase reduction method. As can be seen from Figure 1 , the obtained particles are uniform in size, with an average particle size of 2.1±0.4 nm.

[0029] Figure 2 The metal platinum content in the catalyst after the deposition of platinum on the surface of high-entropy alloy by different cycles. As can be seen from Figure 2 , the platinum content in the catalyst increases with the increase of the number of deposition cycles, indicating that the target platinum content can be accurately controlled by adjusting the implementation parameters of ALD.

[0030] Figure 3 The atomic resolution HAADF-STEM image and element analysis diagram of the platinum-rich catalyst on the surface of high-entropy alloy, with a scale of 1 nm. As can be seen from Figure 3 , HEA and the Pt@HEA series of catalysts obtained by ALD treatment do not show phase separation, and no obvious clusters or particle aggregation are observed at the particle edge, indicating that the platinum deposited by ALD is dispersed at the atomic scale. The element analysis results show that the five elements of Pt, Fe, Co, Ni and Cu are uniformly distributed in the catalyst, and the overall structure maintains the high-entropy characteristics, indicating that the ALD implementation process has no obvious effect on the structure of HEA.

[0031] Figure 4 Tafel slope curves of Pt-enriched high-entropy alloy catalysts. From Figure 4 It can be seen from the figure that the HER performance of the catalysts increases first and then decreases with the change of the degree of surface Pt enrichment. Among them, 3cPt@HEA and 5cPt@HEA show better HER activity; since the platinum loading of 3cPt@HEA is lower, it can have higher atomic utilization efficiency while ensuring higher activity.

[0032] Figure 5 Tafel slope curves of Pt-enriched high-entropy alloy catalysts. From Figure 5 It can be seen from the figure that the HER performance of the catalysts increases first and then decreases with the change of the degree of surface Pt enrichment. Among them, 3cPt@HEA and 5cPt@HEA show better HER activity; since the platinum loading of 3cPt@HEA is lower, it can have higher atomic utilization efficiency while ensuring higher activity. -1

[0033] Figure 6 Tafel slope curves of Pt-enriched high-entropy alloy catalysts. From Figure 6 It can be seen from the figure that 3cPt@HEA shows better HER activity than HEA / C, Pt (a pure Pt catalyst synthesized by the same method as HEA / C), Pt@FeCoNiCu (a comparative catalyst obtained by depositing Pt on FeCoNiCu alloy without Pt by ALD) and commercial 20 wt% Pt / C. DETAILED DESCRIPTION

[0034] In order to make the present application easier to understand, the technical solutions of the present application will be further described below in combination with specific embodiments. The following embodiments are only used to illustrate the present application, and should not be regarded as limiting the scope of protection of the present application.

[0035] Example 1: Preparation of HEA / C

[0036] ​A certain amount of carbon support (C), including but not limited to conductive carbon black (such as Ketjenblack EC-600JD, Vulcan XC-72R, acetylene black), carbon aerogel, mesoporous carbon, nitrogen / oxygen / sulfur hetero-porous carbon, graphite phase carbon nitride (g-C3N4), reduced graphene oxide (rGO), graphene, carbon nanotubes (CNTs), carbon nanofibers (CNFs), hollow carbon spheres, carbon-coated materials, and other carbon-based supports with good electrical conductivity and specific surface area. Preferably, 0.12 g of Ketjenblack EC-600JD carbon support is dispersed in 20 mL of ethanol solution, 0.025 mmol of chloroplatinic acid and 0.1 mmol of each of iron chloride, cobalt chloride, nickel chloride and copper chloride metal salt are added, and ultrasonic dispersion is uniform to obtain solution A. 20 mmmol of sodium borohydride is dispersed in 10 mL of water, ultrasonic dissolution is performed to obtain solution B; solution B is added dropwise to solution A, and stirring reaction is performed for 10 min; after the reaction is completed, suction filtration, washing and 60 ℃ vacuum drying are performed to obtain the HEA / C catalyst. The content of Pt is 1.50 wt%, the content of Fe is 1.82 wt%, the content of Co is 2.04 wt%, the content of Ni is 2.13 wt%, and the content of Cu is 2.63 wt%.

[0037] Example 2: Preparation 1cPt@HEA

[0038] The atomic layer deposition equipment (ACME (Beijing) Technology Co., Ltd.) was used for platinum enrichment on the surface of the high-entropy alloy, and ultra-pure N2 (99.999%) was used as the carrier gas, and the flow rate was 20 sccm.

[0039] MeCpPtMe3 (Sigma-Aldrich, 98%) was used as the metal platinum precursor, the source temperature was set to 65 ℃, and the metal platinum precursor source was fully preheated. The cavity temperature was set to 150 ℃, and one cycle of metal Pt was grown on the HEA / C catalyst synthesized in Example 1 by reacting MeCpPtMe3 with O2. The time sequence of one cycle of Pt atomic layer deposition was t1 (metal platinum precursor exposure time)-t2 (metal platinum precursor removal time)-t3 (oxygen exposure time)-t4 (oxygen removal time), and the corresponding time lengths were 300 s-300 s-600 s-300 s. After depositing one cycle of Pt, the content of Pt in the catalyst was 2.57 wt%.

[0040] Example 3: Preparation 3cPt@HEA

[0041] The platinum enrichment on the surface of high-entropy alloy was carried out by using an atomic layer deposition device (ACME (Beijing) Technology Co., Ltd.). Ultra-pure N2 (99.999%) was used as the carrier gas, and the flow rate was 20 sccm.

[0042] MeCpPtMe3 (Sigma-Aldrich, 98%) was used as the metal platinum precursor, and the source temperature was set to 65 °C. The metal platinum precursor source was fully preheated. The cavity temperature was set to 150 °C. Three cycles of metal Pt were grown on the HEA / C catalyst synthesized in Example 1 by reacting MeCpPtMe3 with O2. The time sequence of one cycle of Pt atomic layer deposition was t1 (metal platinum precursor exposure time)-t2 (metal platinum precursor removal time)-t3 (oxygen exposure time)-t4 (oxygen removal time), and the corresponding time lengths were 300 s-300 s-600 s-300 s, respectively. Three cycles of Pt means that three cycles of one cycle of Pt atomic layer deposition were completed. After depositing three cycles of Pt, the Pt content in the catalyst was 3.97 wt%.

[0043] Example 4: Preparation of 5cPt@HEA

[0044] The platinum enrichment on the surface of high-entropy alloy was carried out by using an atomic layer deposition device (ACME (Beijing) Technology Co., Ltd.). Ultra-pure N2 (99.999%) was used as the carrier gas, and the flow rate was 20 sccm.

[0045] MeCpPtMe3 (Sigma-Aldrich, 98%) was used as the metal platinum precursor, and the source temperature was set to 65 °C. The metal platinum precursor source was fully preheated. The cavity temperature was set to 150 °C. Three cycles of metal Pt were grown on the HEA / C catalyst synthesized in Example 1 by reacting MeCpPtMe3 with O2. The time sequence of one cycle of Pt atomic layer deposition was t1 (metal platinum precursor exposure time)-t2 (metal platinum precursor removal time)-t3 (oxygen exposure time)-t4 (oxygen removal time), and the corresponding time lengths were 300 s-300 s-600 s-300 s, respectively. Five cycles of Pt means that five cycles of one cycle of Pt atomic layer deposition were completed. After depositing five cycles of Pt, the Pt content in the catalyst was 6.01 wt%.

[0046] Example 5: Preparation of 7cPt@HEA

[0047] The platinum enrichment on the surface of high-entropy alloy was carried out by using an atomic layer deposition device (ACME (Beijing) Technology Co., Ltd.). Ultra-pure N2 (99.999%) was used as the carrier gas, and the flow rate was 20 sccm.

[0048] MeCpPtMe3(Sigma-Aldrich, 98%) was used as the metal platinum precursor, and the source temperature was set to 65 °C. The chamber temperature was set to 150 °C. Three cycles of metal Pt were grown on the HEA / C catalyst synthesized in Example 1 by reacting MeCpPtMe3 with O2. The time sequence of one cycle of Pt atomic layer deposition was t1 (metal platinum precursor exposure time) - t2 (metal platinum precursor removal time) - t3 (oxygen exposure time) - t4 (oxygen removal time), and the corresponding time lengths were 300 s - 300 s - 600 s - 300 s, respectively. Seven cycles of Pt, i.e., seven cycles of one cycle of Pt atomic layer deposition, were completed. After seven cycles of Pt deposition, the Pt content in the catalyst was 13.10 wt%.

[0049] Comparative Example 1

[0050] A certain amount of carbon support (C), specifically 0.12 g Ketjenblack EC-600JD, was dispersed in 20 mL of an ethanol solution, and 0.025 mmol of chloroplatinic acid was added and uniformly dispersed by ultrasonic dispersion. Solution A was obtained. 20 mmmol of sodium borohydride was dispersed in 10 mL of water and dissolved by ultrasonic dispersion to obtain solution B; solution B was added dropwise to solution A, and stirring was performed for 10 min; after the reaction was completed, suction filtration, washing, and vacuum drying at 60 °C were performed to obtain a Pt / C catalyst, which was simply denoted as Pt, as Comparative Example 1.

[0051] Comparative Example 2

[0052] A certain amount of carbon support (C), specifically 0.12 g Ketjenblack EC-600JD, was dispersed in 20 mL of an ethanol solution, and 0.1 mmol of each of iron chloride, cobalt chloride, nickel chloride, and copper chloride metal salt was added and uniformly dispersed by ultrasonic dispersion. Solution A was obtained. 20 mmmol of sodium borohydride was dispersed in 10 mL of water and dissolved by ultrasonic dispersion to obtain solution B; solution B was added dropwise to solution A, and stirring was performed for 10 min; after the reaction was completed, suction filtration, washing, and vacuum drying at 60 °C were performed to obtain a FeCoNiCu catalyst.

[0053] Atomic layer deposition equipment (ACME (Beijing) Technology Co., Ltd.) was used to enrich platinum on FeCoNiCu, and ultra-pure N2 (99.999%) was used as the carrier gas, and the flow rate was 20 sccm.

[0054] MeCpPtMe3(Sigma-Aldrich, 98%) was used as the metal platinum precursor, and the source temperature was set to 65 °C. The chamber temperature was set to 150 °C, and three cycles of metal Pt were grown on the synthesized FeCoNiCu catalyst by reacting MeCpPtMe3 with O2. The time sequence of one cycle of Pt atomic layer deposition was t1 (metal platinum precursor exposure time) - t2 (metal platinum precursor removal time) - t3 (oxygen exposure time) - t4 (oxygen removal time), and the corresponding time lengths were 300 s - 300 s - 600 s - 300 s, respectively. Three cycles of Pt were completed by three cycles of one cycle of Pt atomic layer deposition. After depositing three cycles of Pt, the Pt content in the catalyst was 3.70 wt%. This example is denoted as Pt@FeCoNiCu, and is compared with the sample 3cPt@HEA with the best surface platinum enrichment performance.

[0055] Example 3:

[0056] A commercial 20 wt% Pt / C (Sigma-Aldrich) catalyst was used as Example 3.

[0057] Test Example:

[0058] The performance of the examples and comparative examples was tested using a Chenhua electrochemical workstation. A three-electrode system was used, with a graphite electrode as the counter electrode, Ag / AgCl as the reference electrode, and a rotating disc electrode with a diameter of 4 mm as the working electrode. The electrolyte was 0.5 M H2SO4. 4 mg of the catalyst of the example was uniformly dispersed in 920 μL of an ethanol solution, 80 μL of a 5% Nafion solution was added to prepare a catalyst ink, and 10 μL of the catalyst ink was dropped onto the rotating disc electrode and naturally dried to obtain the working electrode. The catalyst was scanned in the potential range of 0.1 V to -0.1 V (vs. RHE) to obtain the polarization curve.

[0059] Other technical materials that are helpful for understanding the present invention

[0060] References:

[0061] [1] Zeng, K.; Zhang, J.; Gao, W.; Wu, L.; Liu, H.; Gao, J.; Li, Z.; Zhou, J.; Li, T.; Liang, Z.; Xu, B.; Yao, Y. Surface-Decorated High-Entropy Alloy Catalysts with Significantly Boosted Activity and Stability. Adv. Funct Mater. 2022, 32 (33), 2204643.

[0062] [2] Zeng, K.; Hu, R.; Zhang, J.; Li, X.; Xu, Y.; Mu, X.; Wu, H.; Liu, S.; Liu, H.; Chen, J.; Wang, Z.; Zhou, J.; Liang, Z.; Gao, W.; Wu, D.; Yao, Y. Finely Tailoring the Local Ensembles in Heterostructured High Entropy Alloy Catalysts through Pulsed Annealing. Nat. Commun. 2025, 16 (1), 3403.

[0063] [3] Wu, C.-Y.; Hsiao, Y.-C.; Chen, Y.; Lin, K.-H.; Lee, T.-J.; Chi, C.-C.; Lin, J.-T.; Hsu, L.-C.; Tsai, H.-J.; Gao, J.-Q.; Chang, C.-W.; Kao, I.-T.; Wu, C.-Y.; Lu, Y.-R.; Pao, C.-W.; Hung, S.-F.; Lu, M.-Y.; Zhou, S.; Yang, T.-H. A Catalyst Family of High-Entropy Alloy Atomic Layers with Square Atomic Arrangements Comprising Iron- and Platinum-Group Metals. Sci. Adv. 2024, 10 (30), eadl3693.

[0064] [4] Shi, W.; Liu, H.; Li, Z.; Li, C.; Zhou, J.; Yuan, Y.; Jiang, F.; Fu, (Kelvin) Kun; Yao, Y. High-entropy Alloy Stabilized and Activated Pt Clusters for Highly Efficient Electrocatalysis. SusMat. 2022, 2 (2), 186-196.

Claims

1. A method for preparing surface platinum-enriched high-entropy alloy hydrogen evolution electrocatalysts using atomic layer deposition technology, characterized in that... Includes the following steps: Step 1: Mix metal salt, carbon support, and sodium borohydride reducing agent in a solvent, and grow high-entropy alloy nanoparticles composed of iron, cobalt, nickel, copper and platinum on the carbon support by liquid-phase reduction method. Step 2: The platinum precursor and oxidant are exposed and removed sequentially using atomic layer deposition technology to achieve controllable deposition of platinum on the surface of the high-entropy alloy, thereby obtaining a high-entropy alloy catalyst enriched with platinum on the surface.

2. The method according to claim 1, characterized in that: In step 1, the amount of metal salt added is 0.01-0.1 mmol, the amount of sodium borohydride added is 10-50 mmol, the amount of carbon support added is 0.1-1 g, and the reaction time is 10-180 min.

3. The method according to claim 1, characterized in that: In step 2, the platinum precursor is trimethyl(methylcyclopentadienyl)platinum.

4. The method according to claim 1, characterized in that: In step 2, the atomic layer deposition sequence is as follows: exposure of platinum precursor, removal of platinum precursor, exposure of oxide, and removal of oxide; the above cycle is one cycle, and the cycle is repeated 1-7 times.

5. The method according to claim 4, characterized in that: The exposure time for the platinum precursor was 100–500 s, and the removal time for the platinum precursor was 200–600 s; the exposure time for the oxidizing agent was 300–600 s, and the removal time for the oxidizing agent was 100–600 s.

6. The method according to claim 5, characterized in that: Repeat the cycle 3-5 times.

7. The method according to claim 1, characterized in that: In the high-entropy alloy catalyst enriched with platinum on the surface, the loading of platinum is 1–13 wt%, and the loading of other metals is 1–3 wt%.

8. A high-entropy alloy catalyst with platinum enrichment on its surface, characterized in that... Prepared according to any one of the preparation methods in claims 1-7.

9. The application of the high-entropy alloy catalyst with platinum enrichment on its surface as described in claim 8 in the electrocatalytic hydrogen evolution reaction.

10. The application according to claim 9, characterized in that: A three-electrode system is used, with a graphite electrode as the counter electrode, Ag / AgCl as the reference electrode, and the surface platinum-enriched high-entropy alloy catalyst as the working electrode, to carry out the electrocatalytic hydrogen evolution reaction.

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