Preparation method and application of Tailing-shaped high-entropy alloy catalyst under interlayer confinement

Abstract

The invention relates to a preparation method and application of a Turing-shaped high-entropy alloy catalyst under an interlayer confinement range, and belongs to the technical field of catalyst preparation and electro-catalysis. According to the method, materials are ingeniously taken, commercialized crystalline flake graphite which is low in cost and resistant to acid and alkali corrosion is particularly selected to be combined with aniline to assist metal salt cation coordination, and simple mixing and sufficient intercalation are conducted firstly. And finally, performing in-situ pyrolysis on the metal salt ions confined between the carbon layers through low-temperature heat treatment, and promoting the formation of a Turing structure pattern with uniform size and uniform distribution by virtue of a confinement diffusion-reaction mechanism, so as to successfully obtain the Turing-shaped high-entropy alloy catalyst. In a performance test, the catalyst shows excellent three-function electro-catalysis HER / ORR / OER activity and stability under an alkaline medium. Furthermore, an oxygen electricity-hydrogen electricity sustainable energy system based on self-driving of the metal-air battery is constructed by virtue of the excellent multifunctional catalytic performance of the catalyst.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of catalyst preparation and electrocatalysis, and particularly relates to a preparation method and application of a Turing-shaped high-entropy alloy catalyst. BACKGROUND

[0002] Greenhouse gas emissions are increasing year by year, leading to the trend of global warming to continue. The core measure of the "double carbon" goal is to carry out a coal power revolution, actively develop renewable energy power generation, further achieve large-scale and safe and stable supply, and gradually reduce dependence on fossil energy. Therefore, under the drive of the "double carbon" goal, the green low-carbon road represented by hydrogen-electricity fusion has become an inevitable choice. Hydrogen energy, as a clean, efficient, safe and sustainable secondary energy, has a wide range of application scenarios and can provide deep decarbonization for traditional industries. Therefore, accelerating the development of green hydrogen production industry taking water electrolysis technology as the core is a strategic choice for countries to respond to global climate change, ensure energy security and achieve high-quality economic and social development, and is of great significance for further accelerating the "double carbon" goal process. In recent years, with the continuous maturation of the hydrogen energy industry chain, the continuous development of preparation technology and the gradual improvement of related industries, the cost of green hydrogen production has further decreased. However, there are still many bottlenecks in the development of current green hydrogen production technology, such as high production cost, lack of special infrastructure, and serious energy loss in the electrolysis process. Therefore, it is urgent to further break through the problems.

[0003] Electrocatalysts can reduce the reaction energy barrier of specific electrochemical reactions to accelerate their reaction kinetics, and even change the reaction mechanism to accelerate the reaction process. However, the key bottleneck to achieve efficient water electrolysis for hydrogen production is to solve the problem of poor activity and stability of the electrocatalyst involved in the hydrogen evolution and oxygen evolution reactions (HER / OER) in the process of alkaline water electrolysis, so as to further develop a low-cost, high-activity, high-stability and dual-functional or multi-functional catalyst electrode material with HER / OER. In addition, the development of multi-functional catalysts (with high activity for multiple reactions) not only can reduce the cost of catalyst development and be applied to different energy conversion and storage devices, but also is necessary for the integration and integration of energy conversion and storage devices. However, the catalytic conditions and reaction paths required by different reactions (such as HER / ORR / OER) are different. For example, the catalysts commonly used for oxygen reduction and oxygen evolution reactions show better activity in alkaline conditions than in acidic conditions, while the catalysts for hydrogen evolution reaction often perform better in acidic conditions, which makes the development and application of energy devices very difficult. Therefore, realizing "one catalyst with multiple functions" is of great significance for the integration of related energy storage and conversion equipment, the improvement of conversion efficiency and the further promotion of the "double carbon" process.

[0004] In view of this, the inventors have developed a simple and efficient method for preparing a Turing-like high-entropy alloy multifunctional catalyst, and successfully prepared a series of ultra-low load platinum-based high-entropy alloy multifunctional catalysts in batches. The method mainly utilizes the diffusion-reaction process in the interlayer space of low-cost and acid and alkali corrosion-resistant commercial flake graphite to synthesize Turing-like high-entropy alloys through a small molecule aniline assisted diffusion strategy. By simply changing the reaction conditions, a series of Turing-like platinum-based high-entropy alloy catalysts with similar sizes and different crystallinities can be synthesized. The catalyst exhibits excellent HER / ORR / OER three-function catalytic performance on a rotating disc electrode and in an alkaline medium. Subsequently, it is further assembled into a self-driven water electrolysis device to effectively address the special situation of unstable power output and intermittent power supply of renewable energy conversion power supply (such as wind power, photovoltaic power, etc.). The above catalyst preparation technology has wide commercial application prospects. SUMMARY

[0005] The present summary is particularly directed to the current problem of slow hydrogen electrochemical reaction kinetics in alkaline medium, and proposes the use of high-entropy alloys as efficient catalysts to design and successfully prepare high-entropy alloy catalysts with excellent multifunctional hydrogen and oxygen electrocatalytic effects. The multifunctional catalyst not only reduces the cost of developing multiple catalysts for different energy conversion and storage devices, but is also necessary for the integration and integration of energy conversion and storage devices.

[0006] TECHNICAL SCHEME

[0007] The present application mainly utilizes the interlayer limited diffusion-reaction process of commercial flake graphite to realize limited synthesis through a small molecule aniline assisted diffusion mechanism. The interlayer limited diffusion-reaction mechanism effectively assists the formation of Turing-like structure of high-entropy alloy. The aniline assisted synthesis strategy can further optimize the dispersion state of nanocrystals. The present application ingeniously selects low-cost and acid and alkali corrosion-resistant commercial flake graphite combined with aniline assisted metal salt cation coordination, which is simply mixed and then fully intercalated. Finally, the metal salt ions limited in the interlayer of carbon are in-situ pyrolyzed by low temperature heat treatment, and the limited diffusion-reaction mechanism is used to promote the formation of uniform size and uniform distribution of Turing structure pattern, and then Turing-like high-entropy alloy catalyst is successfully obtained. In addition, the morphology and structure of the prepared material are comprehensively characterized by AC-STEM, XRD, TEM and other analysis and test methods. In addition, the catalyst exhibits excellent three-function electrocatalytic HER / ORR / OER activity and stability in alkaline medium in performance test. Further, a metal-air battery self-driven oxygen-hydrogen energy system is constructed based on the excellent multifunctional catalytic performance of the catalyst.

[0008] The first object of the present application is to provide a small-size, low-platinum-loading Turing-like high-entropy alloy multifunctional catalyst, which has good structural stability and activity, is resistant to strong oxidation, strong acid and strong base, and has excellent three-function electrocatalytic HER / ORR / OER activity and stability in alkaline media.

[0009] The second object of the present application is to provide a general and batch preparation method of a nanoscale, low-platinum-loading Turing-like high-entropy alloy multifunctional catalyst.

[0010] The third object of the present application is to provide an application of a nanoscale, low-platinum-loading Turing-like high-entropy alloy multifunctional catalyst.

[0011] To achieve the above objects, the present application adopts the following technical solutions:

[0012] The preparation method of the nanoscale, low-platinum-loading Turing-like high-entropy alloy multifunctional catalyst specifically comprises the following steps:

[0013] S1, dispersing a commercialized graphite carbon precursor in a mixed solvent of water and ethanol;

[0014] S2, simultaneously, mixing and dispersing various metal salt precursor solutions and a small molecule compound aniline under ultrasonic assistance;

[0015] S3, adding the mixed and uniform liquid mixture obtained in step S2 to the graphite dispersion liquid of S1;

[0016] S4, ultrasonic dispersion treatment of the mixed and uniform liquid mixture obtained in step S3;

[0017] S5, adding ammonium persulfate to the mixed solution obtained after the ultrasonic dispersion treatment of step S4, and stirring;

[0018] S6, adding sulfuric acid to the mixed solution obtained after the stirring and dispersion treatment of step S5, and stirring;

[0019] S7, ice bath treatment of the solid-liquid mixture obtained in step S6 for a period of time;

[0020] S8, after ice bath, washing treatment, centrifugal separation and vacuum drying using a mixed solvent of water and ethanol;

[0021] S9, sufficiently grinding the solid product obtained in step S8, and then transferring to a high-temperature furnace for hydrogen / argon mixed atmosphere heat annealing treatment, and then reducing to room temperature to obtain the final catalyst product;

[0022] S10, electrochemical performance test;

[0023] In addition, the preparation method of the high-entropy alloy catalyst according to the above-mentioned embodiment steps of the application can further have the following additional technical features.

[0024] In step S1 of the application, the graphite precursor used is commercialized flake graphite.

[0025] In step S2 of the application, all the metal salts used are corresponding chloride metal salt precursors, such as ferric chloride, cobalt chloride, nickel chloride, ruthenium chloride, platinum chloride, manganese chloride, copper chloride, and palladium chloride.

[0026] In step S2 of the application, the mixing and dispersion of the metal salt precursor solution and aniline is carried out under the assistance of ultrasonic, and the ultrasonic treatment time is 1-12 hours.

[0027] In step S5 of the application, the stirring equipment used is a normal-temperature stirring table, the stirring speed is set to 200-1000 revolutions per minute, and the time is 0.5-2 hours.

[0028] In steps S2 and S5 of the application, the molar ratio of aniline to ammonium persulfate added to the system is 1:1.

[0029] In step S8 of the application, the ice bath treatment time of the solid product obtained in step S7 is 24 hours.

[0030] In step S8 of the application, the solid product obtained after centrifugation and washing is subjected to vacuum drying treatment, and the conditions are set as follows: 40-60℃ / 10-24 hours.

[0031] In step S9 of the application, the specific gas used in the annealing stage is 5% hydrogen / argon mixed gas; the heating rate can be 1-10℃ / min, the holding temperature can be 200-800℃, and the holding time can be 0.5-5 hours.

[0032] In step S10 of this invention, electrochemical performance testing is performed using a glassy carbon electrode further prepared with the catalyst obtained in step S9 above as the working electrode and a carbon rod as the counter electrode. In an alkaline medium (with a mercury / mercury oxide electrode as the reference electrode), 0.1 mol / L potassium hydroxide (alkaline) aqueous solutions saturated with nitrogen and oxygen are used as the electrolyte solution, respectively. The linear scan range for the hydrogen evolution reaction is -0.5 to 0 V (relative to the standard hydrogen electrode), with a scan rate of 10 mV / s and a rotation speed of 1600 rpm. The linear scan range for the oxygen reduction reaction is 0 to 1.2 V (relative to the standard hydrogen electrode), with a scan rate of 10 mV / s and a rotation speed of 1600 rpm. The linear scan range for the oxygen evolution reaction is 1.2 to 2.0 V (relative to the standard hydrogen electrode), with a scan rate of 10 mV / s and a rotation speed of 1600 rpm. The present invention also provides the application of the high-entropy alloy catalyst in the hydrogen evolution / oxygen evolution reaction of the alkaline total water splitting process and in the air electrode of a metal-air battery device.

[0033] Beneficial effects

[0034] Compared with the prior art, the beneficial effects achieved by the technical solution of this invention are:

[0035] 1. A solid-phase low-temperature reduction preparation method is adopted, and the synthesis method can achieve preparation at the hundred-gram scale;

[0036] 2. This method adopts a high-temperature reduction route, resulting in high precious metal yield. The catalyst is small in size and uniformly dispersed, making it highly versatile and suitable for large-scale production.

[0037] 3. The synthesis process used in this method is simple and efficient. It only requires five steps: mixing and evaporation, reduction, washing, drying and calcination, to obtain a practical trifunctional catalyst with a clean surface, which has great application potential.

[0038] 4. In addition to the necessary platinum and transition metal precursors, the materials required for this method only include water, ethanol, inexpensive aniline, concentrated sulfuric acid, and ammonium persulfate, which controls the platinum loading and results in lower costs.

[0039] 5. This method has a wide range of applications. By changing the reaction conditions, it is possible to synthesize a variety of Turing-like platinum-based high-entropy alloy catalysts with different compositions and degrees of crystallinity.

[0040] 6. The synthesis process used in this method is relatively stable, and the prepared platinum-based catalyst has excellent trifunctional catalytic performance.

[0041] 7. Small molecule aniline-assisted coordination of metal ions can effectively confine them within the interlayer structure of carbon on a two-dimensional support, enabling them to be uniformly dispersed on the support. This effectively solves the problems of metal precipitation and element segregation, avoids the aggregation of nanocrystals during high-temperature processing, and achieves a high dispersion effect.

[0042] 8、In the sintering process, the reduction in the low temperature zone is controlled to improve the metal dispersion, and the rapid cooling process produces abundant grain boundaries inside the catalyst, thereby exposing more active sites, which is beneficial to improve the catalyst activity.

[0043] 9、The method designs and prepares a Turing-shaped high-entropy alloy catalyst, which has a variable composition space and a unique multi-element mixed structure, can simultaneously realize the design goals of high activity (composition design), high stability (high-entropy stability), and low cost (non-noble metal substitute), realizes high HER / ORR / OER catalytic performance in harsh alkaline environment, and has broad application prospects. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 is the transmission electron microscope image of the catalyst obtained in the first, second, third, fourth, fifth, sixth and seventh embodiments of the application;

[0045] Figure 2 is the X-ray diffraction pattern of the catalyst obtained in the first, second, third, fourth, fifth, sixth and seventh embodiments of the application;

[0046] Figure 3 is the electrochemical performance test graph of the catalyst obtained in the first, second, third, fourth, fifth, sixth and seventh embodiments of the application;

[0047] Figure 4 is the X-ray diffraction pattern of the catalyst obtained in the fourth embodiment of the application;

[0048] Figure 5 is the morphology structure characterization of the catalyst obtained in the fourth embodiment of the application;

[0049] Figure 6 is the electrochemical performance graph of the catalyst obtained in the fourth embodiment of the application and the commercialized catalyst;

[0050] Figure 7 is the electrochemical cycle stability graph of the catalyst obtained in the fourth embodiment of the application and the commercialized catalyst;

[0051] Figure 8 is the full-split water performance and assembled zinc-air battery device performance graph of the catalyst obtained in the fourth embodiment of the application;

[0052] Figure 9 is the long-term stability performance and self-driven full-split water assembly graph of the catalyst obtained in the fourth embodiment of the application;

[0053] Figure 10 is the structure characterization graph of the catalyst obtained in the fourth embodiment of the application after durability test. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of, but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0055] Embodiment 1

[0056] Embodiment 1 of the present application provides a preparation method of a high-entropy alloy multifunctional electrocatalyst, comprising the following steps:

[0057] The specific experimental steps are as follows:

[0058] S1, 1.20 grams of commercial graphite precursor was weighed, and was fully dispersed in a mixed solvent of water (5.0 milliliters) and ethanol (5.0 milliliters) by stirring for 1 hour to make it completely and uniformly dispersed;

[0059] S2, 405.0 milligrams of iron chloride, 561.0 milligrams of cobalt chloride, 357.0 milligrams of nickel chloride, 505.0 milligrams of platinum chloride and 319.0 milligrams of ruthenium chloride were weighed and completely dissolved in 10.0 milliliters of ultrapure water (the molar amount of each metal salt was 1.5 millimoles, and the molar ratio was 1:1), to form a mixed solution of metal salt precursors, and then 0.5 grams of aniline was added and mixed uniformly;

[0060] S3, the liquid mixture obtained in step S2 was added to the graphite dispersion liquid obtained in S1, and was ultrasonically dispersed for 12 hours to make it uniformly dispersed and fully intercalated;

[0061] S4, 1.23 grams of ammonium persulfate was added to the mixed solution obtained after the ultrasonic dispersion treatment in step S3, and was stirred for 12 hours;

[0062] S5, 5.0 milliliters of 0.5 moles per liter of sulfuric acid was added to the mixed solution obtained after the stirring and dispersion treatment in step S4, and was stirred for 12 hours;

[0063] S6, the solid-liquid mixture obtained in step S5 was subjected to ice bath treatment for 24 hours;

[0064] S7, after ice bath, the mixture was washed and treated with a mixed solvent of water and ethanol, and was centrifuged three times, and was vacuum dried under the condition of 60℃ for 12 hours;

[0065] S8, the solid product obtained in step S7 is fully ground, then transferred to a high-temperature furnace for maintaining at 200 degrees Celsius for 3 hours in a hydrogen / argon mixed atmosphere (hydrogen 5%), and then reduced to room temperature to obtain the final catalyst product, denoted as RITD-HEAs-200;

[0066] S9, electrochemical performance test: using the glassy carbon electrode prepared by the catalyst obtained in S8 as the working electrode, carbon rod as the counter electrode, in the alkaline medium (mercury / mercury oxide electrode as the reference electrode), 0.1 mol / L potassium hydroxide (alkaline) aqueous solution saturated with nitrogen and oxygen as the electrolyte solution respectively. The linear scan range of hydrogen evolution reaction is -0.5-0V (relative to standard hydrogen electrode), the scan speed is 10mV / s respectively, the rotation speed is 1600rpm, and the performance test is carried out. The linear scan range of oxygen reduction is 0-1.2V (relative to standard hydrogen electrode), the scan speed is 10mV / s respectively, the rotation speed is 1600rpm, and the performance test is carried out. The linear scan range of oxygen evolution reaction is 1.2-2.0V (relative to standard hydrogen electrode), the scan speed is 10mV / s respectively, the rotation speed is 1600rpm, and the performance test is carried out.

[0067] Example 2

[0068] Example 2 of the present application provides a preparation method of a high-entropy alloy multifunctional electrocatalyst. On the basis of example 1, the reduction temperature is increased to 300℃, and the obtained sample is denoted as example 2 sample.

[0069] The specific experimental steps are as follows:

[0070] S1, 1.20 grams of commercial graphite precursor is weighed, and by stirring, it is fully dispersed in a mixed solvent of water (5.0ml) and ethanol (5.0ml), and stirred for 1 hour to make it completely and uniformly dispersed;

[0071] S2, 405.0 milligrams of iron chloride, 561.0 milligrams of cobalt chloride, 357.0 milligrams of nickel chloride, 505.0 milligrams of platinum chloride and 319.0 milligrams of ruthenium chloride are weighed and completely dissolved in 10.0 milliliters of ultrapure water (the molar amount of each metal salt is 1.5 millimoles, and the molar ratio is 1:1), to form a mixed solution of metal salt precursors, and then 0.5 grams of aniline is added and mixed uniformly;

[0072] S3, the liquid mixture obtained in step S2 is added to the graphite dispersion liquid obtained in S1, and ultrasonic treatment is performed for 12 hours to make it uniformly dispersed and fully intercalated;

[0073] S4, 1.23 grams of ammonium persulfate is added to the mixed solution obtained after the ultrasonic dispersion treatment in step S3, and stirring treatment is performed for 12 hours;

[0074] S5, 5.0 ml of 0.5 mol / L sulfuric acid is added to the mixed solution obtained after the stirring and dispersion treatment in step S4, and stirring treatment is performed for 12 hours;

[0075] S6, the solid-liquid mixture obtained in step S5 is subjected to ice bath treatment for 24 hours;

[0076] S7, after the ice bath is completed, washing treatment, centrifugal separation and vacuum drying are performed three times using a mixed solvent of water and ethanol, and the drying conditions are 60 DEG C for 12 hours;

[0077] S8, the solid product obtained in step S7 is ground, and then transferred to a high-temperature furnace for hydrogen / argon mixed atmosphere (hydrogen 5%) at 300 DEG C for 3 hours, and then cooled to room temperature to obtain the final catalyst product, which is denoted as RITD-HEAs-300;

[0078] S9, electrochemical performance test: the glassy carbon electrode prepared using the catalyst obtained in S8 is used as the working electrode, the carbon rod is used as the counter electrode, the mercury / mercury oxide electrode is used as the reference electrode in the alkaline medium, and the 0.1 mol / L potassium hydroxide (alkaline) aqueous solution saturated with nitrogen and oxygen is used as the electrolyte solution. The hydrogen evolution reaction linear scan range is -0.5-0 V (relative to the standard hydrogen electrode), the scan speed is 10 mV / s, the rotation speed is 1600 rpm, and the performance test is performed. The oxygen reduction linear scan range is 0-1.2 V (relative to the standard hydrogen electrode), the scan speed is 10 mV / s, the rotation speed is 1600 rpm, and the performance test is performed. The oxygen evolution reaction linear scan range is 1.2-2.0 V (relative to the standard hydrogen electrode), the scan speed is 10 mV / s, the rotation speed is 1600 rpm, and the performance test is performed.

[0079] Example 3

[0080] Example 3 of the present application provides a preparation method of a high-entropy alloy multifunctional electrocatalyst. The reduction temperature is increased to 400 DEG C based on example 2, and the obtained sample is denoted as example 3 sample

[0081] The specific experimental steps are as follows:

[0082] S1, 1.20 g of commercial graphite precursor is weighed, and dispersed in a mixed solvent of water (5.0 ml) and ethanol (5.0 ml) by stirring for 1 hour to make it completely and uniformly dispersed;

[0083] S2, 405.0 mg of iron chloride, 561.0 mg of cobalt chloride, 357.0 mg of nickel chloride, 505.0 mg of platinum chloride and 319.0 mg of ruthenium chloride were weighed and completely dissolved in 10.0 ml of ultrapure water (the molar amount of each metal salt was 1.5 mmol, and the molar ratio was 1:1), to form a metal salt precursor mixed solution, and then 0.5 g of aniline was added and uniformly mixed;

[0084] S3, the liquid mixture obtained in step S2 was added to the graphite dispersion liquid obtained in S1, and ultrasonic dispersion was performed for 12 hours to uniformly disperse and fully intercalate;

[0085] S4, 1.23 g of ammonium persulfate was added to the mixed solution obtained after the ultrasonic dispersion treatment in step S3, and stirring treatment was performed for 12 hours;

[0086] S5, 5.0 ml of 0.5 mol / L sulfuric acid was added to the mixed solution obtained after the stirring and dispersion treatment in step S4, and stirring treatment was performed for 12 hours;

[0087] S6, the solid-liquid mixture obtained in step S5 was subjected to ice bath treatment for 24 hours;

[0088] S7, after the ice bath, the mixture was washed and treated with a mixed solvent of water and ethanol, and centrifugal separation was performed three times, followed by vacuum drying at 60°C for 12 hours;

[0089] S8, the solid product obtained in step S7 was sufficiently ground, and then transferred to a high-temperature furnace for treatment at 400°C for 3 hours in a hydrogen / argon mixed atmosphere (hydrogen 5%), and then cooled to room temperature to obtain the final catalyst product, denoted as RITD-HEAs-400;

[0090] S9, electrochemical performance test: the glassy carbon electrode prepared using the catalyst obtained in S8 was used as the working electrode, the carbon rod was used as the counter electrode, and the mercury / mercury oxide electrode was used as the reference electrode in an alkaline medium. The 0.1 mol / L potassium hydroxide (alkaline) aqueous solution saturated with nitrogen and oxygen was used as the electrolyte solution. The linear scan range of the hydrogen evolution reaction was -0.5-0 V (vs. standard hydrogen electrode), the scan speed was 10 mV / s, the rotation speed was 1600 rpm, and the performance test was performed. The linear scan range of the oxygen reduction reaction was 0-1.2 V (vs. standard hydrogen electrode), the scan speed was 10 mV / s, the rotation speed was 1600 rpm, and the performance test was performed. The linear scan range of the oxygen evolution reaction was 1.2-2.0 V (vs. standard hydrogen electrode), the scan speed was 10 mV / s, the rotation speed was 1600 rpm, and the performance test was performed.

[0091] Example 4:

[0092] Embodiment 4 of the present application provides a preparation method of a high-entropy alloy multifunctional electrocatalyst. The reduction temperature is increased to 500 DEG C on the basis of embodiment 3, and the obtained sample is recorded as the sample of embodiment 4

[0093] The specific experimental steps are as follows:

[0094] S1, 1.20 grams of commercial graphite precursor was weighed, and was fully dispersed in a mixed solvent of water (5.0 milliliters) and ethanol (5.0 milliliters) by stirring for 1 hour to make it completely and uniformly dispersed;

[0095] S2, 405.0 milligrams of iron chloride, 561.0 milligrams of cobalt chloride, 357.0 milligrams of nickel chloride, 505.0 milligrams of platinum chloride and 319.0 milligrams of ruthenium chloride were weighed and completely dissolved in 10.0 milliliters of ultrapure water (the molar amount of each metal salt was 1.5 millimoles, and the molar ratio was 1:1), to form a mixed solution of metal salt precursors, and then 0.5 grams of aniline was added and mixed uniformly;

[0096] S3, the liquid mixture obtained in step S2 was added to the graphite dispersion liquid obtained in S1, and was ultrasonically dispersed for 12 hours to make it uniformly dispersed and fully intercalated;

[0097] S4, 1.23 grams of ammonium persulfate was added to the mixed solution obtained after the ultrasonic dispersion treatment in step S3, and was stirred for 12 hours;

[0098] S5, 5.0 milliliters of 0.5 moles per liter of sulfuric acid was added to the mixed solution obtained after the stirring and dispersion treatment in step S4, and was stirred for 12 hours;

[0099] S6, the solid-liquid mixture obtained in step S5 was subjected to ice bath treatment for 24 hours;

[0100] S7, after ice bath, the mixed solvent of water and ethanol was used for washing treatment, and was centrifuged three times, and was vacuum dried under the condition of 60 DEG C for 12 hours;

[0101] S8, the solid product obtained in step S7 was fully ground, and was then transferred to a high-temperature furnace for heat treatment under a hydrogen / argon mixed atmosphere (hydrogen 5%) at 500 DEG C for 3 hours, and then was cooled to room temperature to obtain the final catalyst product, which was recorded as RITD-HEAs-500;

[0102] S9, electrochemical performance test: using the glassy carbon electrode prepared by the catalyst obtained in S8 as the working electrode, carbon rod as the counter electrode, in the alkaline medium (mercury / mercury oxide electrode as the reference electrode), 0.1 mol / L potassium hydroxide (alkaline) aqueous solution saturated with nitrogen and oxygen as the electrolyte solution respectively. The linear scan range of hydrogen evolution reaction is -0.5-0 V (relative to the standard hydrogen electrode), the scan speed is 10 mV / s respectively, the rotation speed is 1600 rpm, and the performance test is carried out. The linear scan range of oxygen reduction is 0-1.2 V (relative to the standard hydrogen electrode), the scan speed is 10 mV / s respectively, the rotation speed is 1600 rpm, and the performance test is carried out. The linear scan range of oxygen evolution reaction is 1.2-2.0 V (relative to the standard hydrogen electrode), the scan speed is 10 mV / s respectively, the rotation speed is 1600 rpm, and the performance test is carried out.

[0103] Example 5

[0104] Example 5 of the present application provides a preparation method of a high-entropy alloy multifunctional electrocatalyst. The reduction temperature is increased to 600 DEG C based on Example 4, and the obtained sample is recorded as Example 5 sample

[0105] The specific experimental steps are as follows:

[0106] S1, 1.20 grams of commercial graphite precursor is weighed, and it is fully dispersed in a mixed solvent of water (5.0 ml) and ethanol (5.0 ml) by stirring for 1 hour to make it completely and uniformly dispersed;

[0107] S2, 405.0 milligrams of iron chloride, 561.0 milligrams of cobalt chloride, 357.0 milligrams of nickel chloride, 505.0 milligrams of platinum chloride and 319.0 milligrams of ruthenium chloride are weighed and completely dissolved in 10.0 milliliters of ultrapure water (the molar amount of each metal salt is 1.5 millimoles, and the molar ratio is 1:1), to form a mixed solution of metal salt precursors, and then 0.5 grams of aniline is added and mixed uniformly;

[0108] S3, the liquid mixture obtained in step S2 is added to the graphite dispersion liquid obtained in S1, and ultrasonic treatment is performed for 12 hours to make it uniformly dispersed and fully intercalated;

[0109] S4, 1.23 grams of ammonium persulfate is added to the mixed solution obtained after the ultrasonic dispersion treatment in step S3, and stirring treatment is performed for 12 hours;

[0110] S5, 5.0 milliliters of 0.5 mol / L sulfuric acid is added to the mixed solution obtained after the stirring and dispersion treatment in step S4, and stirring treatment is performed for 12 hours;

[0111] S6, the solid-liquid mixture obtained in step S5 is subjected to ice bath treatment for 24 hours;

[0112] S7, ice bath is ended, the solid product obtained in step S7 is washed with a mixed solvent of water and ethanol, centrifuged three times, and vacuum dried at 60°C for 12 hours;

[0113] S8, the solid product obtained in step S7 is fully ground, then transferred to a high-temperature furnace, and maintained at 600°C for 3 hours in a hydrogen / argon mixed atmosphere (hydrogen 5%), and then cooled to room temperature to obtain a final catalyst product, denoted as RITD-HEAs-600;

[0114] S9, electrochemical performance test: a glassy carbon electrode prepared using the catalyst obtained in S8 is used as a working electrode, a carbon rod is used as a counter electrode, and a mercury / mercury oxide electrode is used as a reference electrode in an alkaline medium. A 0.1 mol / L potassium hydroxide (alkaline) aqueous solution saturated with nitrogen and oxygen is used as an electrolyte solution. The linear scan range for hydrogen evolution reaction is -0.5-0 V (vs. standard hydrogen electrode), the scan speed is 10 mV / s, the rotation speed is 1600 rpm, and the performance test is performed. The linear scan range for oxygen reduction is 0-1.2 V (vs. standard hydrogen electrode), the scan speed is 10 mV / s, the rotation speed is 1600 rpm, and the performance test is performed. The linear scan range for oxygen evolution reaction is 1.2-2.0 V (vs. standard hydrogen electrode), the scan speed is 10 mV / s, the rotation speed is 1600 rpm, and the performance test is performed.

[0115] Example 6

[0116] Example 6 of the present application provides a preparation method of a high-entropy alloy multifunctional electrocatalyst. The reduction temperature is increased to 700°C based on Example 5, and the obtained sample is denoted as Example 6 sample

[0117] The specific experimental steps are as follows:

[0118] S1, 1.20 grams of a commercial graphite precursor is weighed, and fully dispersed in a mixed solvent of water (5.0 ml) and ethanol (5.0 ml) by stirring for 1 hour to make it completely and uniformly dispersed;

[0119] S2, 405.0 milligrams of iron chloride, 561.0 milligrams of cobalt chloride, 357.0 milligrams of nickel chloride, 505.0 milligrams of platinum chloride, and 319.0 milligrams of ruthenium chloride are weighed and completely dissolved in 10.0 milliliters of ultrapure water (the molar amount of each metal salt is 1.5 millimoles, and the molar ratio is 1:1), to form a mixed solution of metal salt precursors, and then 0.5 grams of aniline is added and mixed uniformly;

[0120] S3, the liquid mixture obtained in step S2 is added to the graphite dispersion liquid obtained in S1, and ultrasonic treatment is performed for 12 hours to make it uniformly dispersed and fully intercalated;

[0121] S4, 1.23 g of ammonium persulfate was added to the mixed solution obtained after the ultrasonic dispersion treatment of step S3, and stirring treatment was performed for 12 hours;

[0122] S5, 5.0 ml of 0.5 mol / L sulfuric acid was added to the mixed solution obtained after the stirring and dispersion treatment of step S4, and stirring treatment was performed for 12 hours;

[0123] S6, the solid-liquid mixture obtained in step S5 was subjected to ice bath treatment for 24 hours;

[0124] S7, after ice bath, washing treatment with a mixed solvent of water and ethanol, centrifugal separation three times, vacuum drying, drying conditions were 60℃, and the drying time was 12 hours;

[0125] S8, the solid product obtained in step S7 was ground, and then transferred to a high-temperature furnace for hydrogen / argon mixed atmosphere (hydrogen 5%) at 700℃ for 3 hours, and then cooled to room temperature to obtain the final catalyst product, denoted as RITD-HEAs-700;

[0126] S9, electrochemical performance test: the glassy carbon electrode prepared using the catalyst obtained in S8 was used as the working electrode, the carbon rod was used as the counter electrode, the mercury / mercury oxide electrode was used as the reference electrode, and the 0.1 mol / L potassium hydroxide (alkaline) aqueous solution saturated with nitrogen and oxygen was used as the electrolyte solution. The linear scan range of hydrogen evolution reaction was -0.5-0V (vs. standard hydrogen electrode), the scan speed was 10 mV / s, the rotation speed was 1600 rpm, and the performance test was performed. The linear scan range of oxygen reduction was 0-1.2V (vs. standard hydrogen electrode), the scan speed was 10 mV / s, the rotation speed was 1600 rpm, and the performance test was performed. The linear scan range of oxygen evolution reaction was 1.2-2.0V (vs. standard hydrogen electrode), the scan speed was 10 mV / s, the rotation speed was 1600 rpm, and the performance test was performed.

[0127] Example 7:

[0128] Example 7 of the present application provides a preparation method of a high-entropy alloy multifunctional electrocatalyst. The reduction temperature is increased to 800℃ based on example 6, and the obtained sample is denoted as example 7 sample

[0129] The specific experimental steps are as follows:

[0130] S1, 1.20 g of commercial graphite precursor was weighed, and was dispersed in a mixed solvent of water (5.0 ml) and ethanol (5.0 ml) by stirring for 1 hour to make it completely and uniformly dispersed;

[0131] S2, 405.0 milligrams of iron chloride, 561.0 milligrams of cobalt chloride, 357.0 milligrams of nickel chloride, 505.0 milligrams of platinum chloride and 319.0 milligrams of ruthenium chloride are weighed and completely dissolved in 10.0 milliliters of ultrapure water (the molar amount of each metal salt is 1.5 millimoles, and the molar ratio is 1:1) to form a metal salt precursor mixed solution, and then 0.5 grams of aniline is added and uniformly mixed;

[0132] S3, the liquid mixture obtained in step S2 is added to the graphite dispersion liquid obtained in S1, and ultrasonic treatment is performed for 12 hours to uniformly disperse and intercalate;

[0133] S4, 1.23 grams of ammonium persulfate is added to the mixed solution obtained after the ultrasonic dispersion treatment in step S3, and stirring treatment is performed for 12 hours;

[0134] S5, 5.0 milliliters of 0.5 moles per liter of sulfuric acid is added to the mixed solution obtained after the stirring and dispersion treatment in step S4, and stirring treatment is performed for 12 hours;

[0135] S6, the solid-liquid mixture obtained in step S5 is subjected to ice bath treatment for 24 hours;

[0136] S7, after the ice bath treatment, the mixture is washed and treated with a mixed solvent of water and ethanol, and centrifugal separation is performed three times, and vacuum drying is performed at 60℃ for 12 hours;

[0137] S8, the solid product obtained in step S7 is sufficiently ground, and then transferred to a high-temperature furnace for hydrogen / argon mixed gas atmosphere (hydrogen 5%) at 800℃ for 3 hours, and then cooled to room temperature to obtain the final catalyst product, which is denoted as RITD-HEAs-800;

[0138] S9, electrochemical performance test: the glassy carbon electrode prepared using the catalyst obtained in S8 is used as the working electrode, the carbon rod is used as the counter electrode, the mercury / mercury oxide electrode is used as the reference electrode, and the 0.1 moles per liter of potassium hydroxide (alkaline) aqueous solution saturated with nitrogen and oxygen is used as the electrolyte solution. The linear scan range of the hydrogen evolution reaction is -0.5-0V (relative to the standard hydrogen electrode), the scan speed is 10 millivolts per second, the rotation speed is 1600 revolutions per minute, and the performance test is performed. The linear scan range of the oxygen reduction reaction is 0-1.2V (relative to the standard hydrogen electrode), the scan speed is 10 millivolts per second, the rotation speed is 1600 revolutions per minute, and the performance test is performed. The linear scan range of the oxygen evolution reaction is 1.2-2.0V (relative to the standard hydrogen electrode), the scan speed is 10 millivolts per second, the rotation speed is 1600 revolutions per minute, and the performance test is performed.

[0139] Test results of the application:

[0140] The present application is particularly directed to the problem of slow kinetics of hydrogen electrochemical reactions in current alkaline media, and proposes the use of high-entropy alloys as efficient catalysts. Multifunctional hydrogen-oxygen electrochemical high-entropy alloy catalysts with excellent catalytic performance are designed and successfully prepared. The present application ingeniously selects low-cost, acid and alkali corrosion resistant commercialized flake graphite combined with aniline assisted metal salt cation coordination. Through simple mixing and intercalation between molecular layers, the metal salt ions confined in the carbon layer are in-situ pyrolyzed by low-temperature heat treatment, and the formation of uniform size and uniform distribution of Turing structure patterns is promoted by the confined reaction-diffusion mechanism, and then the Turing-shaped high-entropy alloy catalyst is successfully obtained. In addition, the morphology and structure of the prepared material are comprehensively characterized by AC-STEM, XRD, TEM and other analysis and testing methods. The catalyst shows excellent three-function electrocatalytic HER / ORR / OER activity and stability in alkaline medium in performance test. Further, an oxygen-hydrogen energy system based on metal-air battery self-driven is constructed by virtue of the excellent multifunctional catalytic properties of the catalyst.

[0141] The prepared Turing-shaped high-entropy alloy multifunctional catalyst has the characteristics of uniform size and uniform distribution, and presents a Turing pattern state, which can be shown from the transmission electron micrograph of the alloy catalyst. Figure 1 As can be seen from the figure, the particle size of the catalyst increases as the reduction temperature increases, but the average particle size is still less than 10 nm. Figure 2 It is shown that the catalyst prepared in all examples is a face-centered cubic crystal structure (FCC), and the standard card below is a carbon (CJCPDS No. 12-0212) and a platinum face-centered cubic crystal phase card (Pt JCPDS No. 04-0802); Figure 3 The bifunctional (ORR / OER) performance chart of the catalyst obtained from examples 1-7 can be seen, and when the reduction temperature is controlled at 500 DEG C (the catalyst obtained from example 4), the catalyst performance is better; more detailed XRD analysis of the catalyst obtained from example 4 ( Figure 4 ) shows that the XRD characteristic peak shifts to the right, and there is obvious lattice compression strain, which is beneficial to the improvement of catalytic activity; in addition, more detailed morphology and structure analysis of the catalyst obtained from example 4 ( Figure 5 ) confirms that RITD-HEAs-500 has the most typical Turing morphology ( Figure 5 a,b), high-resolution confirms that there are rich grain boundary structures in the crystal ( Figure 5 c), there is lattice compression strain ( Figure 5 d) and the crystal structure also conforms to the FCC structure ( Figure 5 e), which is consistent with the above XRD analysis result ( Figure 4 ); further, the grain boundary distribution is analyzed in detail by means of spherical aberration correction high-resolution transmission (Figure 5 f), the results prove the existence of abundant interfaces, including heterogeneous phase grain boundary interfaces ( Figure 5 g), twin boundary interfaces ( Figure 5 f7), and lattice mismatched dislocation interfaces, the existence of these abundant interfaces can be beneficial to its catalytic activity; in addition, the element distribution map ( Figure 5 h) can be seen that each element is uniformly distributed, and there is no element segregation phenomenon. Figure 6 It is shown that the catalyst prepared in Example 4 has the most outstanding three-function catalytic performance, and the catalytic activity and durability performance ( Figure 7 ) are better than the commercial standard catalyst; most importantly, the catalyst prepared in Example 4 has better performance in full water splitting and zinc-air battery device performance ( Figure 8 ); further, by virtue of the outstanding multifunctional catalytic properties of the catalyst, a self-driven oxygen-hydrogen energy system based on metal-air battery ( Figure 9 ) can be constructed, which can effectively cope with the special situation of intermittent power supply. Figure 10 It can be seen that the catalyst prepared by the method of the present application has greatly improved activity and stability compared with the traditional Pt / C catalyst.

[0142] In summary, the preparation method of the Turing-like high-entropy alloy catalyst described in the examples of the present application mainly uses the reaction-diffusion mechanism in the limited space between the graphite carbon layers and the aniline assisted synthesis strategy to effectively help the formation of the Turing-like morphology of the high-entropy alloy and promote the preparation of the target catalyst. The Turing-like morphology is more conducive to the formation and maintenance of abundant interfaces, which helps to fully expose the active sites and improve the catalytic activity. The aniline assisted synthesis strategy is conducive to achieving high dispersion of nanocrystals without damaging the catalyst structure, limiting metal migration and agglomeration, and avoiding agglomeration of nanocrystals during further high temperature treatment. The catalyst exhibits excellent HER / ORR / OER three-function catalytic performance on a rotating disc electrode and in an alkaline medium. The development of the above multifunctional electrocatalyst can reduce the cost of developing multiple catalysts for different energy conversion and storage devices, and is conducive to the integration and integration of energy conversion and storage devices. As a self-driven water electrolysis device is further assembled, it can effectively cope with intermittent power supply and realize the design concept of "one catalyst with multiple functions", so the catalyst preparation technology involved in this technology has wide commercial application prospects.

[0143] Special notes:

[0144] In this disclosure, the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" mean that a particular feature, structure, material, or characteristic is included in at least one embodiment or example of the present disclosure. The illustrative appearances of the above-mentioned terms in various places in the specification are not necessarily referred to the same embodiment or example. Moreover, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples. Furthermore, the terminology "comprising" is used in the disclosure as comprising but not limited to, that is, it is open-ended and does not exclude the presence of additional features, structures, materials, or characteristics.

[0145] Although the embodiments of the present disclosure have been shown and described above, it should be understood by those having ordinary skill in the art that the above-mentioned embodiments are exemplary and should not be construed as limiting the present disclosure, and those skilled in the art can make changes, modifications, replacements, and variations to the above-mentioned embodiments within the scope of the present disclosure.

Claims

1. A method for preparing and using a high-entropy alloy catalyst with interlayer confinement and Turing-like behavior, comprising the following steps: S1. Dispersing a commercial graphite carbon precursor in a mixed solvent of water and ethanol; S2. Simultaneously, mixing and dispersing various metal salt precursor solutions and a small molecule compound, aniline, under ultrasonic assistance; S3. Adding the mixed and uniform liquid mixture obtained in step S2 to the graphite dispersion liquid of S1; S4. Ultrasonic dispersion treatment of the mixed and uniform liquid mixture obtained in step S3; S5. Adding ammonium persulfate to the mixed solution obtained after the ultrasonic dispersion treatment of step S4 and stirring; S6. Adding sulfuric acid to the mixed solution obtained after the stirring and dispersion treatment of step S5 and stirring; S7. Ice bath treatment of the solid-liquid mixture obtained in step S6 for a period of time; S8. After ice bath, washing treatment with a mixed solvent of water and ethanol, centrifugal separation, and vacuum drying; S9. Thoroughly grinding the solid product obtained in step S8, then transferring it to a high-temperature furnace for heat annealing treatment under a hydrogen / argon mixed atmosphere, and then cooling to room temperature to obtain the final catalyst product; S10. Electrochemical performance test; In addition, the method for preparing a high-entropy alloy catalyst according to the above implementation steps of the present application can also have the following additional technical features: In step S1 of the present application, the graphite precursor used is commercialized flake graphite; In step S2 of the present application, all the metal salts used are corresponding chloride metal salt precursors, such as iron chloride, cobalt chloride, nickel chloride, ruthenium chloride, platinum chloride, manganese chloride, copper chloride, and palladium chloride; In step S2 of the present application, the metal salt precursor solution and aniline are mixed and dispersed under ultrasonic assistance, and the ultrasonic treatment time is 1-12 hours; In step S5 of the present application, the stirring equipment used is a normal temperature stirring table, the stirring speed is set to 200-1000 revolutions per minute, and the time is 0.5-2 hours; In steps S2 and S5 of the present application, the molar ratio of aniline to ammonium persulfate added to the system is 1:1; In step S8 of the present application, the ice bath treatment time of the solid product obtained in step S7 is 24 hours; In step S8 of the present application, vacuum drying treatment of the solid product obtained after centrifugation and washing is performed under the following conditions: 40-60℃ / 10-24 hours; In step S9 of the present application, the specific gas used in the annealing stage is a 5% hydrogen / argon mixed gas; the heating rate can be 1-10℃ / min, the holding temperature can be 200-800℃, and the holding time can be 0.5-5 hours; In step S10 of the present application, electrochemical performance test: using the catalyst prepared in step S9 above, further prepare a glassy carbon electrode as the working electrode, a carbon rod as the counter electrode, in an alkaline medium (mercury / mercury oxide electrode as the reference electrode), and 0.1 mol / L potassium hydroxide (alkaline) aqueous solution saturated with nitrogen and oxygen as the electrolyte solution. The hydrogen evolution reaction linear scan range is-0.5-0 V (relative to the standard hydrogen electrode), the scan speed is 10 mV / s, and the rotation speed is 1600 rpm, and the performance test is carried out. The oxygen reduction linear scan range is 0-1.2 V (relative to the standard hydrogen electrode), the scan speed is 10 mV / s, and the rotation speed is 1600 rpm, and the performance test is carried out. The oxygen evolution reaction linear scan range is 1.2-2.0 V (relative to the standard hydrogen electrode), the scan speed is 10 mV / s, and the rotation speed is 1600 rpm, and the performance test is carried out. The present application also provides the high-entropy alloy catalyst for hydrogen evolution / oxygen evolution reaction in the alkaline overall water splitting process and in the air electrode of the metal-air battery device.

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