High-entropy selenide catalyst, preparation method and application thereof

Abstract

The application provides a high-entropy selenide catalyst and a preparation method and application thereof, and the preparation method comprises the following steps: mixing a carbon material and a non-noble metal salt solution to obtain a mixture; the mixture is dried and ground to obtain a metal salt precursor; selenium powder and the metal salt precursor are mixed and subjected to thermal shock to obtain the high-entropy selenide catalyst; and the mass ratio of the selenium powder to the metal in the metal salt precursor is (1-8):1. The application has the high-entropy effect of multi-element mixing and the selenium ligand regulates the coordination environment of the metal, so that the catalytic performance and stability of the obtained high-entropy selenide catalyst are improved; the thermal shock can effectively prevent alloy particle agglomeration, maximally maintains the structural uniformity of the high-entropy selenide catalyst, avoids phase segregation, avoids the use of noble metals, reduces the preparation cost, and is simple in process, easy to control, short in flow, and beneficial to realize the large-scale production of the high-entropy selenide catalyst.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of water electrolysis catalyst materials, and relates to a catalyst and a preparation method and application thereof, in particular to a high-entropy selenide catalyst and a preparation method and application thereof. BACKGROUND

[0002] Hydrogen energy, as the cleanest energy with the highest heat value and the lowest pollution and greenhouse gas emission, has attracted widespread attention. Large-scale hydrogen production technology is an essential key technology for the sustainable development of hydrogen energy. Compared with the carbon-based energy steam reforming process used in industrial hydrogen production, water electrolysis hydrogen production technology can realize pollution-free "green" hydrogen production by using renewable energy power, and is considered to be an ideal hydrogen production method in the future.

[0003] As a new type of alloy material, the design concept of high-entropy alloy breaks the traditional single main element design framework of alloy and creates a new alloy system. Although the main element of high-entropy alloy is multiple, it has high-performance phases such as simple cubic solid solution phase, nano-particle dispersion phase, amorphous phase, and non-fragile intermetallic compound. This organizational structure characteristic makes high-entropy alloy have excellent properties such as high hardness, high strength, high corrosion resistance, and high-temperature oxidation resistance, which cannot be compared with traditional alloy materials. Alloy nanoparticles exhibit different properties from pure metal nanoparticles in catalysis, electrochemistry, optics, and other aspects.

[0004] CN115058729A discloses an iridium-based high-entropy alloy nanocatalyst for oxygen evolution reaction and a preparation method thereof. The invention successfully prepared an iridium-based high-entropy alloy nanomaterial by an oil phase synthesis method, and added glucose during the synthesis process to make the nanocrystal size uniform. The "cocktail effect" and synergistic effect between the constituent elements make it have excellent oxygen evolution catalytic activity. In a 1 mol / L potassium hydroxide solution, only 360 mV of overpotential is needed to reach a current density of 10 mA / cm 2 , with a Tafel slope as low as 54 mV / dec and excellent long-term stability.

[0005] CN113774422A discloses a preparation method of a PdCuFeCoNi high-entropy alloy nanoparticle catalyst applied to water electrolysis. Pd, Cu, Fe, Co, and Ni reduced metal salts are added to an oil amine solvent, and a surfactant is used to prevent high-entropy alloy nanoparticles from agglomerating and control their formation of specific morphology. A washing solution is prepared to clean the alloy surface oil amine and surfactant, and high-dispersion, uniform-particle-size high-entropy alloy nanoparticles are obtained. The high-entropy alloy particles are loaded with carbon black XC-72 to obtain their water electrolysis catalyst. The catalyst exhibits excellent hydrogen evolution and oxygen evolution performance at full pH, and is a high-efficiency water electrolysis catalyst.

[0006] The most effective water electrolysis catalysts at present are still noble metal catalysts such as platinum, iridium and ruthenium, but their reserves are low, the price is high, and they are difficult to run stably in long-term high-power electrolysis, which leads to the inability to realize large-scale industrial application and popularization. Therefore, the research on cheap, abundant, efficient and stable catalyst materials has become the key to promoting the development of hydrogen production by water electrolysis and hydrogen energy economy.

[0007] CN114892062A discloses a porous high-entropy alloy material for efficient hydrogen production and a preparation method thereof. According to the atomic percentage of metal elements, it contains 10-25% of Cr, 10-15% of Fe, 3-8% of V, 5-15% of Mn, and the balance of Ni. The percentage of V and Mn is 20-50%. The synergistic effect of Ni, Cr, Fe, V and Mn elements is utilized, and the heat treatment strengthening is combined with solid solution and aging precipitation. The catalytic performance of V and Mn elements makes the material have relatively high electrocatalytic hydrogen evolution activity and low reaction overpotential, which can realize good catalysis, is beneficial to the adsorption and desorption of ions in the electrolytic hydrogen evolution process, and realizes the preparation effect of efficient and stable hydrogen. However, the technical scheme process is complex, not easy to control, and the preparation period is long, which is not conducive to large-scale batch production.

[0008] The present application provides a high-entropy selenide catalyst, a preparation method and application thereof. The process is simple, easy to control, short, and conducive to the realization of large-scale production of high-performance mixed and uniform non-noble metal high-entropy nanocatalysts. SUMMARY

[0009] The present application provides a high-entropy selenide catalyst, a preparation method and application thereof. The preparation method can effectively solve the problem of particle agglomeration, the process is simple, easy to control, short, and conducive to the realization of large-scale production of high-performance mixed and uniform non-noble metal high-entropy nanocatalysts.

[0010] To achieve the purpose of the present application, the following technical solutions are adopted:

[0011] In a first aspect, the present application provides a preparation method of a high-entropy selenide catalyst, which comprises the following steps:

[0012] (1) mixing a carbon material and a non-noble metal salt solution to obtain a mixture; the mixture is dried and ground to obtain a metal salt precursor;

[0013] (2) mixing selenium powder with the metal salt precursor obtained in step (1) and subjecting to thermal shock to obtain the high-entropy selenide catalyst;

[0014] The mass ratio of the selenium powder to the metal in the metal salt precursor obtained in step (1) in step (2) is (1-8):1.

[0015] In the present invention, the carbon material serves as a carrier to improve the conductivity of the obtained high-entropy selenide catalyst, and also acts as a reducing agent to effectively reduce the non-precious metal salt to a metal element. The metal element diffuses and undergoes in-situ selenization during the thermal shock process. Selenium powder can regulate the coordination environment of the metal element, thereby improving the catalytic activity and stability of the obtained high-entropy selenide catalyst. At the same time, the thermal shock has the characteristics of rapid heating and rapid cooling, which can effectively prevent the agglomeration of alloy particles, maximize the structural uniformity of the high-entropy selenide catalyst, and avoid phase segregation. The present invention uses a non-precious metal salt solution as a raw material, avoids the use of precious metals, greatly reduces the preparation cost, has a simple process, is easy to control, and has a short process flow, which is conducive to the large-scale production of high-entropy selenide catalysts.

[0016] The mass ratio of the selenium powder in step (2) of the present invention to the metal in the metal salt precursor obtained in step (1) is (1-8):1, which is beneficial to regulating the coordination environment of the metal element during the selenization process and improving the catalytic performance of the obtained high-entropy selenide catalyst. For example, it can be 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1 or 8:1, but is not limited to the listed values. Other unlisted values ​​within this numerical range are also applicable. When the mass ratio is lower than 1:1, the selenium powder does not thoroughly regulate the metal coordination environment, affecting the catalytic performance of the obtained high-entropy selenide catalyst; when the mass ratio is higher than 8:1, excess selenium powder will cause incomplete exposure of the metal active sites, thereby reducing the catalytic performance.

[0017] Preferably, the D80 particle size of the selenium powder in step (2) is 150-250 mesh, for example, 150 mesh, 180 mesh, 200 mesh, 220 mesh or 250 mesh, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0018] Preferably, the temperature of the thermal shock in step (2) is 750-950°C, for example, 750°C, 800°C, 850°C, 900°C or 950°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0019] In the present invention, the temperature of the thermal shock is controlled within the range of 750-950° C., which can effectively solve the problem of particle agglomeration of the high-entropy selenide catalyst, ensure its structural uniformity, and avoid phase segregation. When the temperature is lower than 750° C., it is insufficient to reduce the non-noble metal salt and form a high-entropy selenide catalyst with selenium powder, resulting in phase segregation of the material, thereby reducing activity and stability. When the temperature is higher than 950° C., the particles of the obtained high-entropy selenide catalyst are easily agglomerated, which is not conducive to the progress of the catalytic reaction.

[0020] Preferably, the time of the thermal shock in step (2) is 15-35 s, for example, it can be 15 s, 20 s, 25 s, 30 s or 35 s, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0021] The time of the thermal shock in the present application is controlled in the range of 15-35 s, which can effectively solve the problem of particle agglomeration of the high-entropy selenide catalyst, ensure the structural uniformity, and avoid phase segregation; when the time is less than 15 s, the non-noble metal salt is not completely reduced and forms a high-entropy selenide with selenium powder, resulting in phase segregation of the material, thereby reducing the activity and stability; when the time is more than 35 s, the particles are prone to agglomeration, affecting the catalytic activity.

[0022] Preferably, the relative pressure of the thermal shock in step (2) is -0.05 to 0.1 MPa, for example, it can be -0.05 MPa, -0.04 MPa, -0.03 MPa, -0.02 MPa, -0.01 MPa, 0 MPa, 0.05 MPa or 0.1 MPa, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0023] Preferably, the thermal shock in step (2) is carried out in a protective atmosphere.

[0024] Preferably, the protective atmosphere comprises nitrogen and / or an inert gas.

[0025] Preferably, the inert gas comprises any one or a combination of at least two of helium, neon, argon, krypton or xenon, and a typical but non-limiting combination includes a combination of helium and neon, a combination of neon and argon, a combination of argon and krypton, a combination of krypton and xenon, or a combination of helium, neon and argon.

[0026] Preferably, the solid-liquid ratio of the carbon material to the non-noble metal salt solution in step (1) is (0.5-3):1, for example, it can be 0.5:1, 0.8:1, 1:1, 1:2 or 3:1, but is not limited to the listed values, and other values not listed in the range are also applicable, and the unit of the solid-liquid ratio is g / L.

[0027] Preferably, the mass ratio of the non-noble metal in the non-noble metal salt solution to the carbon material in step (1) is (5-25):100, for example, it can be 5:100, 8:100, 10:100, 13:100, 15:100, 18:100, 20:100, 23:100 or 25:100, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0028] Preferably, the carbon material in step (1) comprises carbon black XC-72.

[0029] Preferably, the molar concentration of the metal salt solution in step (1) is 0.005-0.1 mol / mL, for example, it can be 0.005 mol / mL, 0.01 mol / mL, 0.02 mol / mL, 0.03 mol / mL, 0.04 mol / mL, 0.05 mol / mL, 0.06 mol / mL, 0.07 mol / mL, 0.08 mol / mL, 0.09 mol / mL or 0.1 mol / mL, but is not limited to the listed values, other values not listed within the range of values are also applicable.

[0030] Preferably, the non-noble metal salt in the non-noble metal salt solution in step (1) includes iron salt, nickel salt, cobalt salt, chromium salt and copper salt.

[0031] Preferably, the molar fraction of iron element in the iron salt relative to the non-noble metal elements in the non-noble metal salt solution in step (1) is 5-40%, for example, it can be 5%, 10%, 15%, 20%, 25%, 30%, 35% or 40%, but is not limited to the listed values, other values not listed within the range of values are also applicable.

[0032] Preferably, the molar fraction of nickel element in the nickel salt relative to the non-noble metal elements in the non-noble metal salt solution in step (1) is 5-40%, for example, it can be 5%, 10%, 15%, 20%, 25%, 30%, 35% or 40%, but is not limited to the listed values, other values not listed within the range of values are also applicable.

[0033] Preferably, the molar fraction of cobalt element in the cobalt salt relative to the non-noble metal elements in the non-noble metal salt solution in step (1) is 5-40%, for example, it can be 5%, 10%, 15%, 20%, 25%, 30%, 35% or 40%, but is not limited to the listed values, other values not listed within the range of values are also applicable.

[0034] Preferably, the molar fraction of chromium element in the chromium salt relative to the non-noble metal elements in the non-noble metal salt solution in step (1) is 5-40%, for example, it can be 5%, 10%, 15%, 20%, 25%, 30%, 35% or 40%, but is not limited to the listed values, other values not listed within the range of values are also applicable.

[0035] Preferably, the molar fraction of copper element in the copper salt relative to the non-noble metal elements in the non-noble metal salt solution in step (1) is 5-40%, for example, it can be 5%, 10%, 15%, 20%, 25%, 30%, 35% or 40%, but is not limited to the listed values, other values not listed within the range of values are also applicable.

[0036] Preferably, the non-noble metal salt in the non-noble metal salt solution in step (1) comprises any one or a combination of at least two of nitrate, acetate, acetylacetone or chloride, typical but not limited combinations include a combination of nitrate and acetate, a combination of acetate and acetylacetone, a combination of acetylacetone and chloride, a combination of nitrate, acetate and acetylacetone, a combination of acetate, acetylacetone and chloride, or a combination of nitrate, acetate, acetylacetone and chloride.

[0037] Preferably, the solvent of the non-noble metal salt solution in step (1) is a mixture of ethanol and water.

[0038] Preferably, the volume ratio of ethanol to water in the mixture of ethanol and water is (1-6): 1, for example, it can be 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1 or 6:1, but not limited to the listed values, other values not listed in this range are also applicable.

[0039] Preferably, the temperature of the mixing in step (1) is 20-30℃, for example, it can be 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃ or 30℃, but not limited to the listed values, other values not listed in this range are also applicable.

[0040] Preferably, the time of the mixing in step (1) is 20-28h, for example, it can be 20h, 21h, 22h, 23h, 24h, 25h, 26h, 27h or 28h, but not limited to the listed values, other values not listed in this range are also applicable.

[0041] Preferably, the mixing in step (1) is accompanied by stirring, and the stirring rate is 300-600r / min, for example, it can be 300r / min, 350r / min, 400r / min, 450r / min, 500r / min, 550r / min or 600r / min, but not limited to the listed values, other values not listed in this range are also applicable.

[0042] Preferably, the temperature of the drying in step (1) is 60-100℃, for example, it can be 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃ or 100℃, but not limited to the listed values, other values not listed in this range are also applicable.

[0043] Preferably, the drying in step (1) is performed for 8-12 hours, for example, 8 hours, 9 hours, 10 hours, 11 hours or 12 hours, but not limited to the listed values, other values not listed in the range are also applicable.

[0044] Preferably, the drying in step (1) is accompanied by stirring at a stirring rate of 300-600 r / min, for example, 300 r / min, 350 r / min, 400 r / min, 450 r / min, 500 r / min, 550 r / min or 600 r / min, but not limited to the listed values, other values not listed in the range are also applicable.

[0045] As a preferred technical solution of the preparation method of the first aspect of the present application, the preparation method comprises the following steps:

[0046] (1) mixing carbon material and non-noble metal salt solution at a solid-liquid ratio of (0.5-3):1 g / L at 20-30℃ for 20-28 hours, and drying at 60-100℃ for 8-12 hours to obtain a metal salt precursor;

[0047] The drying is accompanied by stirring at a stirring rate of 300-600 r / min;

[0048] The drying is accompanied by stirring at a stirring rate of 300-600 r / min;

[0049] The non-noble metal salt solution comprises iron salt, nickel salt, cobalt salt, chromium salt and copper salt;

[0050] The solvent of the non-noble metal salt solution is a mixture of ethanol and water;

[0051] The mass ratio of non-noble metal in the non-noble metal salt solution to the carbon material is (5-25):100;

[0052] (2) mixing selenium powder with the metal salt precursor obtained in step (1), and performing thermal shock at 750-950℃ for 15-35 seconds in a protective atmosphere to obtain the high-entropy selenide catalyst;

[0053] The mass ratio of selenium powder to metal in the metal salt precursor is (1-8):1.

[0054] In a second aspect, the present application provides a high-entropy selenide catalyst, which is obtained by the preparation method of the first aspect.

[0055] In a third aspect, the present application provides an electrolytic cell, wherein the anode of the electrolytic cell comprises the high-entropy selenide catalyst of the second aspect.

[0056] Compared with the prior art, the present invention has the following beneficial effects:

[0057] In the present invention, a metal salt precursor and selenium powder are subjected to thermal shock to obtain a high-entropy selenide catalyst, which has a high-entropy effect of a multi-element mixture; the selenium ligand regulates the coordination environment of the metal to improve the catalytic performance and stability of the obtained high-entropy selenide catalyst; at the same time, the thermal shock has the characteristics of rapid heating and cooling, which can effectively prevent the agglomeration of alloy particles, maximize the maintenance of the structural uniformity of the high-entropy selenide catalyst, and avoid phase segregation; and the use of precious metals is avoided, which greatly reduces the preparation cost, has a simple process, is easy to control, and has a short flow, which is conducive to the large-scale production of the high-entropy selenide catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 This is a STEM image of the high-entropy selenide catalyst obtained in Example 1.

[0059] Figure 2 This is the XRD pattern of the high entropy selenide catalyst obtained in Example 1.

[0060] Figure 3 The high entropy selenide catalyst obtained in Example 1 is 10mA / cm 2 Constant current stability test diagram under current density.

[0061] Figure 4 The high entropy selenide catalyst obtained in Example 1 is 100mA / cm 2 Constant current stability test diagram under current density. DETAILED DESCRIPTION

[0062] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0063] Example 1

[0064] This embodiment provides a method for preparing a high-entropy selenide catalyst, the preparation method comprising the following steps:

[0065] (1) A non-noble metal salt solution containing ferric nitrate, nickel chloride, cobalt acetate, chromium chloride, and copper nitrate with a concentration of 0.01 mol / mL was mixed with a carbon material at 25°C for 24 hours, dried at 90°C for 10 hours, and ground to obtain a metal salt precursor;

[0066] The molar fractions of iron, nickel, cobalt, chromium and copper in the non-noble metal salt solution are 20%, 20%, 20%, 20% and 20% of the total molar amount of the metal elements, respectively;

[0067] The mixing and drying are accompanied by stirring, and the stirring speed is 500 r / min;

[0068] The solvent of the non-noble metal salt solution is a mixture of ethanol and water in a volume ratio of 4:1;

[0069] The solid-liquid ratio of the carbon material to the non-noble metal salt solution is (1:1) g / L;

[0070] The mass ratio of non-noble metal in the non-noble metal salt solution to the carbon material is 20:100;

[0071] (2) The selenium powder is mixed with the metal salt precursor obtained in step (1), and heat shock is performed at 800 DEG C for 20 s in a helium atmosphere, and the relative pressure during heat shock is 0 MPa, to obtain the high-entropy selenide catalyst;

[0072] The mass ratio of the selenium powder to the metal in the metal salt precursor is 4:1.

[0073] Example 2

[0074] The embodiment provides a preparation method of a high-entropy selenide catalyst, and the preparation method comprises the following steps:

[0075] (1) A non-noble metal salt solution containing iron acetylacetone, nickel nitrate, cobalt chloride, chromium nitrate and copper chloride with a concentration of 0.005 mol / mL is mixed with a carbon material at 20 DEG C for 28 h, and dried at 100 DEG C for 8 h, and then grinded to obtain a metal salt precursor;

[0076] The mole fractions of iron, nickel, cobalt, chromium and copper in the non-noble metal salt solution are 5%, 40%, 10%, 40% and 5% of the total metal element mole amount, respectively;

[0077] The mixing and drying are accompanied by stirring, and the stirring speed is 300 r / min;

[0078] The solvent of the non-noble metal salt solution is a mixture of ethanol and water in a volume ratio of 1:1;

[0079] The solid-liquid ratio of the carbon material to the non-noble metal salt solution is (0.5:1) g / L;

[0080] The mass ratio of non-noble metal in the non-noble metal salt solution to the carbon material is 25:100;

[0081] (2) The selenium powder is mixed with the metal salt precursor obtained in step (1), and heat shock is performed at 750 DEG C for 35 s in an argon atmosphere, and the relative pressure during heat shock is 0.1 MPa, to obtain the high-entropy selenide catalyst;

[0082] The mass ratio of the selenium powder to the metal in the metal salt precursor is 1:1.

[0083] Embodiment 3

[0084] The embodiment provides a preparation method of a high-entropy selenide catalyst, and the preparation method comprises the following steps:

[0085] (1) mixing a non-noble metal salt solution containing iron acetate, nickel acetate, cobalt nitrate, chromium chloride and copper nitrate with a concentration of 0.1 mol / mL and a carbon material at 30 DEG C for 20 h, drying at 60 DEG C for 12 h, and grinding to obtain a metal salt precursor;

[0086] The molar fractions of iron, nickel, cobalt, chromium and copper in the non-noble metal salt solution are 40%, 5%, 40%, 5% and 10% of the total molar amount of metal elements respectively;

[0087] The mixing and drying are accompanied by stirring, and the stirring speed is 600 r / min;

[0088] The solvent of the non-noble metal salt solution is a mixture of ethanol and water in a volume ratio of 6:1;

[0089] The solid-liquid ratio of the carbon material to the non-noble metal salt solution is (3:1) g / L;

[0090] The mass ratio of the non-noble metal in the non-noble metal salt solution to the carbon material is 5:100;

[0091] (2) mixing selenium powder with the metal salt precursor obtained in step (1), and performing thermal shock at 950 DEG C for 15 s in a nitrogen atmosphere, wherein the relative pressure during the thermal shock is-0.05 MPa, to obtain the high-entropy selenide catalyst;

[0092] The mass ratio of the selenium powder to the metal in the metal salt precursor is 8:1.

[0093] Embodiment 4

[0094] The embodiment provides a preparation method of a high-entropy selenide catalyst, and the preparation method is same as that in Embodiment 1, except that the temperature of thermal shock in step (2) is 700 DEG C.

[0095] Embodiment 5

[0096] The embodiment provides a preparation method of a high-entropy selenide catalyst, and the preparation method is same as that in Embodiment 1, except that the temperature of thermal shock in step (2) is 1000 DEG C.

[0097] Embodiment 6

[0098] The embodiment provides a preparation method of a high-entropy selenide catalyst, wherein, except that the time of thermal shock in step (2) is 10s, the rest are the same as those in embodiment 1.

[0099] Embodiment 7

[0100] The embodiment provides a preparation method of a high-entropy selenide catalyst, wherein, except that the time of thermal shock in step (2) is 40s, the rest are the same as those in embodiment 1.

[0101] Comparative example 1

[0102] The embodiment provides a preparation method of a high-entropy selenide catalyst, wherein, except that the mass ratio of selenium powder to metal in the metal salt precursor in step (2) is 0.5:1, the rest are the same as those in embodiment 1.

[0103] Comparative example 2

[0104] The embodiment provides a preparation method of a high-entropy selenide catalyst, wherein, except that the mass ratio of selenium powder to metal in the metal salt precursor in step (2) is 9:1, the rest are the same as those in embodiment 1.

[0105] Comparative example 3

[0106] The embodiment provides a preparation method of a high-entropy alloy catalyst, wherein, except that no selenium powder is added in step (2), the rest are the same as those in embodiment 1, and finally a high-entropy alloy catalyst is obtained.

[0107] Comparative example 4

[0108] The comparative example provides a commercial iridium oxide catalyst, which is from Zhongkekechuang.

[0109] Performance test

[0110] Electrochemical tests and stability tests are conducted on the high-entropy selenide catalysts provided in embodiments 1-7 and comparative examples 1-2, the high-entropy alloy catalyst provided in comparative example 3 and the commercial iridium oxide catalyst provided in comparative example 4, and the test method is as follows:

[0111] 5mg of the high-entropy selenide catalysts in embodiments 1-7 and comparative examples 1-2, the high-entropy alloy catalyst in comparative example 3 and the commercial iridium oxide catalyst in comparative example 4 are respectively taken in 1mL centrifuge tubes, and are added to a mixed solution containing 450ul of ethanol and 50ul of 5% Nafion, and then are uniformly mixed by ultrasonic and are dropped on 0.25cm 2 hydrophilic carbon paper, wherein, the loading of Ir in comparative example 4 is 0.2mg / cm 2After the solvent is completely volatilized at room temperature, electrochemical test and stability test are carried out; the electrochemical test system is a three-electrode system, a platinum sheet is used as a counter electrode, carbon paper is used as a working electrode, mercury / mercury oxide is used as a reference electrode, and a 1M KOH solution is used as an electrolyte.

[0112] The overpotential (mV@10mA / cm 2 ) of the current density reaching 10mA / cm 2 is tested, and the attenuation rate (%) after 100h of current density 10mA / cm 2 is tested, and the results are shown in Table 1.

[0113] Table 1

[0114]

[0115]

[0116] The overpotential of the high-entropy selenide catalyst in the process of catalyzing electrolysis of water is as low as 222mV@10mA / cm 2 , and the attenuation rate after 100h of current density 10mA / cm 2 is only 0.2%, so the high-entropy selenide catalyst has good catalytic activity and stability.

[0117] Figure 1 The STEM image of the high-entropy selenide catalyst obtained in Example 1 can be seen to have a narrow particle size distribution, with a particle size of about 200nm, and the metals are evenly distributed on the particles, proving that the high-entropy selenide catalyst is successfully synthesized; Figure 2 The XRD image of the high-entropy selenide catalyst obtained in Example 1 can be seen to have a single-phase CoSe structure; Figure 3 and Figure 4 are the constant current stability test images of the high-entropy selenide catalyst obtained in Example 1 at current densities of 10mA / cm 2 and 100mA / cm 2 , respectively, and it can be seen that the high-entropy selenide catalyst prepared in the application can be stably operated for more than 100h at current densities of 10mA / cm 2 and 100mA / cm 2 , indicating that the synthesized high-entropy selenide catalyst has good stability.

[0118] From the comparison of Examples 4 and 5 with Example 1, it can be seen that the temperature of the thermal shock in the present invention is controlled in the range of 750-950°C, which can improve the catalytic activity and stability of the obtained high-entropy selenide catalyst in the water electrolysis process; when the temperature is lower than 750°C, it is not enough to reduce the non-precious metal salt and form a high-entropy selenide catalyst with the selenium powder, resulting in phase segregation of the material, thereby reducing the activity and stability; when the temperature is higher than 950°C, the particles of the obtained high-entropy selenide catalyst are easily agglomerated, which is not conducive to the catalytic reaction and leads to a decrease in catalytic stability.

[0119] From the comparison of Examples 6 and 7 with Example 1, it can be seen that the thermal shock time in the present invention is controlled within the range of 15-35 s, which can ensure that the obtained high-entropy selenide catalyst has good catalytic activity and stability in the water electrolysis process; when the time is less than 15 s, the non-precious metal salt is not completely reduced and forms a high-entropy selenide with the selenium powder, resulting in phase segregation of the material, thereby reducing the activity and stability; when the time is more than 35 s, the particles are likely to agglomerate, affecting the catalytic activity.

[0120] From the comparison of Comparative Examples 3 and 4 with the embodiment, it can be seen that when the mass ratio of selenium powder to the metal in the metal salt precursor is lower than 1:1, the selenium powder does not thoroughly regulate the metal coordination environment, thereby affecting the catalytic performance of the resulting high-entropy selenide catalyst; when the mass ratio is higher than 8:1, the excess selenium powder will cause incomplete exposure of the metal active sites, resulting in reduced catalytic performance. Therefore, controlling the mass ratio of selenium powder to the metal in the metal salt precursor to (1-8):1 is beneficial to regulating the coordination environment of the metal element during selenization, thereby improving the catalytic performance and stability of the resulting high-entropy selenide catalyst.

[0121] From the comparison between Comparative Example 3 and Example 1, it can be seen that the overpotential of the high entropy alloy catalyst without adding selenium powder in the process of catalyzing the electrolysis of water is 264mV@10mA / cm 2 , 10mA / cm 2 The attenuation rate after 100 h of circulation is 1%. Therefore, the high-entropy selenide catalyst provided by the present invention is beneficial to reducing the overpotential during the reaction process and improving the catalytic activity and stability of water electrolysis.

[0122] From the comparison between Comparative Example 4 and Example 1, it can be seen that the overpotential of the commercial iridium oxide catalyst in the process of catalyzing the electrolysis of water is 275mV@10mA / cm 2 , 10mA / cm 2 The decay rate after 10 h of circulation is 20%, so the high-entropy selenide catalyst provided by the present invention has good catalytic activity and stability for water electrolysis.

[0123] In summary, the application provides a high-entropy selenide and a preparation method and application thereof, the high-entropy selenide catalyst is obtained by heat shock of metal salt precursors and selenium powder, and has a high-entropy effect of multi-element mixing; the selenium ligand regulates the coordination environment of the metal, thereby improving the catalytic performance and stability of the obtained high-entropy selenide catalyst; meanwhile, the heat shock has the characteristics of rapid heating and cooling, can effectively prevent alloy particle agglomeration, maximally maintains the structural uniformity of the high-entropy selenide catalyst, avoids phase segregation, and avoids the use of noble metals, thereby greatly reducing the preparation cost, the process is simple, easy to control, the flow is short, and the application is conducive to realizing the large-scale production of the high-entropy selenide catalyst.

[0124] The above merely describes a specific implementation of the application, but the protection scope of the application is not limited thereto, and those skilled in the art should understand that any change or replacement within the technical scope disclosed by the application can be easily thought of by those skilled in the art, and falls within the protection scope and disclosure scope of the application.

Claims

1. A method for preparing a high-entropy selenide catalyst, characterized in that, The preparation method comprises the following steps: (1) mixing a carbon material and a non-noble metal salt solution to obtain a mixture; the mixture is dried and ground to obtain a metal salt precursor; (2) mixing selenium powder and the metal salt precursor obtained in step (1) and performing thermal shock to obtain the high-entropy selenide catalyst; The temperature of the thermal shock is 750-950℃; The time of the thermal shock is 15-35s; The relative pressure of the thermal shock is -0.05 to 0.1 MPa; The thermal shock is performed in a protective atmosphere; The mass ratio of the selenium powder to the metal in the metal salt precursor obtained in step (1) in step (2) is (1-8):

1.

2. The production method according to claim 1, characterized by, The D80 particle size of the selenium powder in step (2) is 150-250 mesh.

3. The production method according to claim 1, characterized by, The protective atmosphere comprises nitrogen and / or an inert gas.

4. The production method according to claim 3, characterized by, The inert gas comprises any one or a combination of at least two of helium, neon, argon, krypton or xenon.

5. The preparation method according to claim 1, characterized in that The solid-liquid ratio of the carbon material to the non-noble metal salt solution in step (1) is (0.5-3):1, and the unit of the solid-liquid ratio is g / L.

6. The method of claim 1, wherein, The mass ratio of the non-noble metal in the non-noble metal salt solution to the carbon material in step (1) is (5-25):

100.

7. The preparation method according to claim 1, characterized in that The carbon material in step (1) comprises carbon black XC-72.

8. The method of claim 1, wherein, The molar concentration of the metal salt solution in step (1) is 0.005-0.1 mol / mL.

9. The method of claim 1, wherein, The non-noble metal salt in the non-noble metal salt solution in step (1) comprises iron salt, nickel salt, cobalt salt, chromium salt and copper salt.

10. The method of claim 9, wherein, The mole fraction of iron in the iron salt relative to the non-noble metal elements in the non-noble metal salt solution in step (1) is 5-40%.

11. The preparation method according to claim 9, characterized in that The mole fraction of nickel in the nickel salt relative to the non-noble metal elements in the non-noble metal salt solution in step (1) is 5-40%.

12. The method of claim 9, wherein, The mole fraction of cobalt in the cobalt salt relative to the non-noble metal elements in the non-noble metal salt solution in step (1) is 5-40%.

13. The preparation method according to claim 9, characterized in that The mole fraction of chromium in the chromium salt relative to the non-noble metal elements in the non-noble metal salt solution in step (1) is 5-40%.

14. The method of claim 9, wherein, The mole fraction of copper in the copper salt relative to the non-noble metal elements in the non-noble metal salt solution in step (1) is 5-40%.

15. The method of claim 1, wherein, The non-noble metal salt in the non-noble metal salt solution in step (1) comprises any one or a combination of at least two of nitrate, acetate, acetylacetone salt or chloride salt.

16. The method of claim 1, wherein, The solvent of the non-noble metal salt solution in step (1) is an ethanol and water mixture.

17. The method of claim 16, wherein the method further comprises, The volume ratio of ethanol to water in the ethanol and water mixture is (1-6):

1.

18. The method of claim 1, wherein, The temperature of the mixing in step (1) is 20-30℃.

19. The method of claim 1, wherein, The time of the mixing in step (1) is 20-28h.

20. The method of claim 1, wherein, The mixing in step (1) is accompanied by stirring, and the stirring rate is 300-600r / min.

21. The method of claim 1, wherein, The temperature of the drying in step (1) is 60-100℃.

22. The method of claim 1, wherein, The time of the drying in step (1) is 8-12h.

23. The method of claim 1, wherein, The drying in step (1) is accompanied by stirring, and the stirring rate is 300-600r / min.

24. The method of claim 1, wherein, The preparation method comprises the following steps: (1) mixing carbon material and non-precious metal salt solution with a solid-liquid ratio of (0.5-3):1 g / L at 20-30℃ for 20-28h, drying at 60-100℃ for 8-12h, and grinding to obtain metal salt precursor; the drying is accompanied by stirring at a stirring rate of 300-600r / min; the drying is accompanied by stirring at a stirring rate of 300-600r / min; the non-precious metal salt solution comprises iron salt, nickel salt, cobalt salt, chromium salt and copper salt; the solvent of the non-precious metal salt solution is a mixture of ethanol and water; the mass ratio of non-precious metal in the non-precious metal salt solution to the carbon material is (5-25):100; (2) mixing selenium powder with the metal salt precursor obtained in step (1), and performing thermal shock at 750-950℃ for 15-35s in a protective atmosphere to obtain the high-entropy selenide catalyst; the mass ratio of the selenium powder to the metal in the metal salt precursor is (1-8):

1.

25. A high-entropy selenide catalyst, characterized in that, The high-entropy selenide catalyst is obtained by the preparation method of any one of claims 1-24.

26. An electrolytic cell characterized by The anode of the electrolytic cell comprises the high-entropy selenide catalyst of claim 25.

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