An atomic-level controllable high-entropy catalyst, a preparation method and application thereof

Abstract

This invention provides an atomically controllable high-entropy catalyst, its preparation method, and its applications. The catalyst comprises a support and an active component; the catalyst support is selected from commercially available carbon supports; the active component is selected from five or more metals with catalytic activity; wherein the metal atoms in the active component are atomically dispersed on the support. This invention employs an alkali metal melting method to prepare an atomically controllable high-entropy catalyst. Based on the controllable mass ratio between metal atoms and the catalyst support, its specific surface area ensures the formation of an atomically dispersed high-entropy metal catalyst, thereby improving the catalytic activity of the high-entropy catalyst in carbon dioxide reduction, water electrolysis for hydrogen production, and oxygen reduction fuel cells. The high-entropy catalyst prepared by this invention has a simple process, controllable parameters, and recyclable byproducts, which is beneficial for the industrial production and application of high-entropy catalysts.

Description

Technical Field

[0001] This invention relates to the field of electrocatalysis technology, specifically to an atomically controllable high-entropy catalyst, its preparation method, and its applications. Background Technology

[0002] With the widespread use of fossil fuels, global energy is being rapidly depleted. Utilizing renewable resources such as solar, wind, and electricity to convert carbon dioxide into fuels with high chemical value, such as ethanol and formic acid, is crucial. However, the thermodynamic energy barrier for carbon dioxide reduction is high; therefore, developing catalysts with high selectivity and low overpotential is key to its widespread application. Hydrogen energy is a clean and renewable energy source applicable to various scenarios and is also crucial in the future global energy strategy. However, efficient hydrogen production urgently requires stable and economical catalysts. Furthermore, fuel cells are more environmentally friendly and pollution-free because they do not involve carbon-containing materials in the energy conversion process. However, currently commercially available catalysts are mostly precious metal catalysts, which are expensive and exhibit poor stability in practical applications. Therefore, it is also necessary to develop a low-cost and highly stable electrocatalyst.

[0003] High-entropy alloys, also known as multi-principal-element alloys, are solid solutions formed by mixing multiple metals in appropriate proportions. These elements can work synergistically, providing diverse adsorption sites for catalytic reactions. The high mechanical strength and corrosion resistance of high-entropy materials facilitate their stable application in various catalytic environments. Compared to nanoparticle catalysts, single-atom catalysts exhibit increased active surface area and improved catalytic activity. However, the preparation of high-entropy single-atom catalysts currently faces challenges such as complex processes and catalyst instability. Therefore, methods for preparing atomically controllable high-entropy catalysts are crucial for achieving efficient catalysis and large-scale industrial applications. Summary of the Invention

[0004] The present invention aims to provide a large-scale, atomically controlled, high-entropy catalyst, its preparation method, and its applications, enabling the high-energy-density reduction of carbon dioxide to high-value fuels, low-overpotential catalytic hydrogen production from water electrolysis, and the preparation and application of highly efficient and stable atomically dispersed high-entropy catalysts in oxygen reduction fuel cells. This invention uses a molten lithium (sodium, potassium, rubidium, cesium) method to prepare atomically dispersed metal catalysts supported on a catalytic substrate, wherein the catalytic metal exists primarily in single-atom form. These electrocatalysts have been shown to exhibit high efficiency and low overpotential, as well as high selectivity and stability for the formation of carbon dioxide reduction products ethanol and hydrocarbons. According to the embodiments, highly selective electrocatalytic reduction of carbon dioxide to formic acid, methanol, ethanol, etc., is achieved, suitable for large-scale electrocatalytic CO2 reduction.

[0005] The first aspect of this invention provides a method for preparing an atomically controllable high-entropy catalyst, comprising the following steps:

[0006] (1) Preparation of molten alkali metals under anhydrous and oxygen-free conditions;

[0007] (2) Add the catalytic metal to the molten alkali metal to obtain a molten alkali metal-catalytic metal mixture;

[0008] (3) After cooling the molten alkali metal-catalytic metal mixture, place it in a humid environment to obtain an alkali metal hydroxide-catalytic metal mixture;

[0009] (4) Mix the alkali metal hydroxide-catalytic metal mixture with the catalyst support evenly, then slowly rinse with a dropping funnel to remove the alkali metal hydroxide, and then dry to obtain an atomically controllable high-entropy catalyst.

[0010] In the technical solution of the invention, the operation of removing alkali metal hydroxides is to slowly rinse with water using a dropping funnel to remove the alkali metal hydroxides. The process can be carried out by suction filtration or not.

[0011] As a preferred implementation method,

[0012] In step (1), the alkali metal in the molten alkali metal is selected from lithium, sodium, potassium, rubidium and cesium.

[0013] As a preferred implementation method,

[0014] In step (2), the number of metal types corresponding to the catalytic metal is ≥4;

[0015] Preferably, the catalytic metal is selected from transition metals, main group metals, lanthanides, and actinides;

[0016] More preferably,

[0017] The transition metal is selected from at least one of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Pt, or Cd; and / or,

[0018] The main group metal is selected from at least one of Mg, Ca, Sr, Ba, B, Al, Ga, In, Tl, Ge, Sn, Pb, As, Sb, Bi, Se, Te, or Po; and / or,

[0019] The lanthanides are selected from at least one of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, or lutetium; and / or,

[0020] The actinide metals are selected from at least one of actinium, thorium, protactinium, uranium, neptunium, plutonium, americium, curium, or berkelium;

[0021] More preferably, the number of metal species corresponding to the catalytic metal is ≥5.

[0022] In the technical solution of the present invention, the catalytic metal is selected from a variety of metals, and the present invention has discovered that the synergistic effect of metal atoms in the above-mentioned multi-metal catalyst forms more catalytic centers, thereby further improving the catalytic activity of the catalyst; since different metals have different adsorption reaction sites, the selectivity of the product can be improved by regulating the d-band electronic structure.

[0023] As a preferred implementation method,

[0024] The catalytic metal is selected from four or more metals selected from Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Ge, Sn, Pb, As, Sb, Bi, Se, Te, Po, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, La-based, Ac-based, Hf, Ta, W, Re, Os, Ir, Pt, Au, and Hg.

[0025] Preferably, the catalytic metal is selected from five metals chosen from Cu, Sn, In, Bi, Pt, Ag, Ni, Ir, Pd, Ru, Rh, Fe, and Co;

[0026] More preferably, the catalytic metal is one of five metals: Cu, Sn, In, Bi, and Pt, and the preferred molar ratio of the five metals is 1:1:1:1:1; and / or,

[0027] The catalytic metal is one of five metals: Sn, In, Cu, Ag, and Ni, preferably in a molar ratio of 1:1:1:1:1; and / or,

[0028] The catalytic metal is one of five metals: Ir, Pd, Ru, Rh, and Pt, preferably in a molar ratio of 1:1:1:1:1; and / or,

[0029] The catalytic metal is one of five metals: Pt, Fe, Sn, Cu, and Co, with a preferred molar ratio of 1:1:1:1:1.

[0030] As a preferred implementation method,

[0031] In the catalytic metal, the total stoichiometry of four or more metals selected from transition metals, main group metals, lanthanides and actinides should be 100%, wherein the mass content of each transition metal, main group metal, lanthanide and actinide metal is independently selected from 10% to 60%.

[0032] Preferably,

[0033] The total stoichiometry of five or more metals selected from the catalytic metals (transition metals, main group metals, lanthanides, and actinides) should be 100%, wherein the mass content of each transition metal, main group metal, lanthanide, and actinide metal is independently selected from 10% to 60%.

[0034] As a preferred implementation method,

[0035] The molar ratio of the total mass of the catalytic metal to the alkali metal is (0.01% to 25%):1; for example, 0.01%:1, 0.1%:1, 1%:1, 4%:1, 10%:1, 15%:1, 20%:1, 25%:1.

[0036] The alkali metal is kept in the molten state for 0.5 to 10 hours; for example, 0.5, 1, 3, 5, 7, or 10 hours.

[0037] As a preferred implementation method,

[0038] Cooling time ≤ 20 minutes;

[0039] The humid environment is a humid air environment, preferably with a relative humidity (RH) of 50% to 100%;

[0040] The placement time is 24h to 72h; for example, 24, 30, 35, 40, 50, 60, or 72 hours.

[0041] As a preferred implementation method,

[0042] In step (4), the catalyst support is selected from carbon supports, preferably one or more of common commercial carbon powder, carbon black, carbon with high specific surface area such as graphene, and carbon nanotubes; and / or,

[0043] In the catalyst, the mass ratio of catalytic metal to catalyst support is 0.01% to 10%; preferably 0.01% to 5%; for example, 0.01%, 0.1%, 0.5%, 0.8%, 1%, 1.5%, 2%, 3%, 5%, 8%, 10%; and / or,

[0044] The method of achieving uniform mixing is mechanical mixing, preferably by grinding; and / or,

[0045] The drying method involves vacuum drying at 50-100℃.

[0046] A second aspect of the present invention provides a catalyst prepared by a method for preparing an atomically controllable high-entropy catalyst as described in any one of the first aspects of the present invention. The catalyst includes a support and an active component; the active component is selected from four or more metals with catalytic activity; wherein the metal atoms in the active component are atomically dispersed on the support; preferably, the active component is selected from five or more metals with catalytic activity.

[0047] In the catalyst described in this invention, the mass ratio of catalytic metal to catalyst support is 0.01% to 10%; preferably 0.01% to 5%; more preferably 0.01% to 1%; for example, 0.01%, 0.1%, 0.5%, 0.8%, 1%, 1.5%, 2%, 3%, 5%, 8%, and 10%.

[0048] The third aspect of this invention provides a catalyst prepared by the method for preparing an atomically controllable high-entropy catalyst as described in the first aspect of this invention, or the application of the catalyst as described in the second aspect of this invention as an electrocatalyst in an electroreduction reaction; preferably,

[0049] The catalyst is used as an electrocatalyst for the reduction of formic acid by CO2; and / or,

[0050] The catalyst is used as an electrocatalyst for the reduction of CO2 to methanol; and / or,

[0051] The catalyst is used as an electrocatalyst for the reduction of CO2 to ethanol; and / or,

[0052] The catalyst is used as an electrocatalyst for the reduction of acetic acid by CO2; and / or,

[0053] The catalyst is used as an electrocatalyst for hydrogen production via water electrolysis; and / or,

[0054] The catalyst is used as an electrocatalyst in an oxygen reduction fuel cell.

[0055] More specifically, the technical solution for large-scale preparation of atomically controllable high-entropy catalysts in this invention includes the following steps:

[0056] Step 1: Add multiple bulk metal catalytic metals to molten alkaline metal, wherein the catalytic metal sources added to the molten metal should include at least five metals;

[0057] Step 2: Add catalytic metal atoms to the molten alkali metal obtained in Step 1 until they are uniformly dispersed. Then, quickly quench the melt to form a solid solution and avoid the aggregation of metal components, forming an alkali metal-high entropy metal solid.

[0058] Step 3: Cut the alkali metal-high entropy metal solid obtained in Step 2 into small pieces and place them in a humid environment to convert the alkali metal into alkali metal hydroxide, forming a high entropy metal-alkali metal hydroxide solid.

[0059] Step 4: Mix the high-entropy metal-basic metal hydroxide solid described in Step 3 with the catalytic substrate material;

[0060] Step 5: Remove the alkaline metal hydroxide ions from the mixture described in Step 4, leaving an atomically dispersed high-entropy metal mixture on the catalytic substrate material (i.e., catalyst support). This is achieved by filtering the mixture described in Step 4 while slowly rinsing it to remove the alkali metal hydroxides.

[0061] Step 6: Dry the catalytic substrate-supported atomically dispersed metal mixture described in Step 5 to prepare an electrocatalyst with a catalytic substrate-supported high-entropy metal atomic dispersion.

[0062] According to the embodiments, the catalytic metals suitable for preparing the electrocatalysts of the present invention include four or more metals selected from Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Ge, Sn, Pb, As, Sb, Bi, Se, Te, Po, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, La-based, Ac-based, Hf, Ta, W, Re, Os, Ir, Pt, Au, and Hg, which are then reacted with molten lithium to form a Li-polymetallic melt.

[0063] Metals with melting points below 300℃ that can form solid solutions with lithium are preferred choices for electrocatalyst preparation, such as Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Ge, Sn, Pb, As, Sb, Bi, Se, Te, Po, Cu, Zn, Mo, Tc, Ru, Rh, Pd, Ag, and Cd. It is particularly important to note that metal single atoms can be formed directly in the form of ingots, wires, powders, or fragments, followed by drying and reduction steps. Under an inert atmosphere, transition metals dispersed in a hot lithium solution have a molten lithium temperature between 180℃ and 1330℃, which is between the melting and boiling points of lithium. For other alkali metals used in the melt, the temperature range is also between their respective melting and boiling points.

[0064] The alkali metal, including Li, Na, K, Rb, Cs, and other alkali materials, can be used as a melting medium to dissolve the aforementioned metals into a solid solution. In a preferred example, lithium is added to the melt (commonly referred to as lithium melt) as a melting medium because it has the largest range between its melting and boiling points.

[0065] The cutting method may also use one of the following mechanical methods: rolling, stamping or breaking down the solid solution into smaller pieces to promote interaction with moisture and air, wherein the relative humidity (RH) of the humidified air is preferably 50% to 100%.

[0066] The surface area of ​​the catalytic substrate material support is greater than 20m². 2 / g. The range is within 20m. 2 / g to 800m 2 / g. The catalyst substrate can be a commercial carbon support, such as graphene, carbon nanotubes, common commercial carbon powder, carbon black, metal oxides, or it can be based on high surface area materials, such as, but not limited to, metal-organic frameworks and chitosan-derived carbon supports, ensuring that metal atoms can be uniformly dispersed on a carbon matrix support with high specific surface area and high porosity. Using a carbon matrix support ensures that metal atoms (single or multiple metals) are uniformly distributed on the above scaffold, thus avoiding or reducing agglomeration.

[0067] This catalyst has the following advantages:

[0068] 1. The catalyst prepared by this invention exhibits good stability and catalytic activity. According to the preparation method of this invention, oxygen-containing functional groups, such as -OH and -COOH, are generated during the rinsing process with alkaline hydroxide, acting as anchoring sites and maintaining a highly dispersed state of metal atoms. Therefore, the catalyst of this invention exhibits long-term stability.

[0069] 2. The catalyst of the present invention can electrocatalyze the reduction of carbon dioxide to a single product with high selectivity, overcoming the shortcomings of low selectivity and low Faraday efficiency in the existing carbon dioxide reduction process.

[0070] 3. The active components of this invention can be selected from existing transition metals and non-transition metals with high reserves, resulting in lower costs.

[0071] 4. The high degree of atomic dispersion in this invention requires only a low loading to achieve high catalytic activity, further reducing the cost of the catalyst.

[0072] 6. The high-entropy catalyst prepared by this invention can achieve synergistic effects of multiple metals and can achieve synergistic response through structural adaptation and electronic conversion, thereby achieving high activity and selectivity. Attached Figure Description

[0073] The foregoing and other features of the invention will be more fully appreciated from the following description and appended claims, in conjunction with the accompanying drawings. Since these drawings illustrate only a few embodiments according to the invention and should not be considered as limiting its scope, the invention will be described in other detailed ways using the accompanying drawings.

[0074] Figure 1 A schematic diagram of the synthesis steps for dispersing high-entropy metal single atoms of CuSnInBiPt using the lithium melting method;

[0075] Figure 2 The nuclear magnetic resonance spectrum of a carbon-supported CuSnInBiPt catalyst with a total metal mass fraction of 0.1% for the production of formic acid at -0.6 V;

[0076] Figure 3 Time-current density curves (It plots) of carbon-supported CuSnInBiPt catalyst with a total catalytic metal mass fraction of 0.1% were tested at -0.6 V.

[0077] Figure 4 Current-voltage polarization curves of SnInCuAgNi high-entropy catalyst with a total carbon loading of 0.8% under different atmospheres;

[0078] Figure 5 Cyclic voltammetry curves and fitted electrochemical active areas of a high-entropy SnInCuAgNi catalyst with a total carbon loading of 0.8% at different scan rates are presented.

[0079] Figure 6 The time-current density curve (It plot) of the SnInCuAgNi high-entropy catalyst with a total carbon loading of 0.8% by mass is tested at -0.8V. Detailed Implementation

[0080] The technical solution of the present invention will be further described below with reference to the accompanying drawings, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention that do not depart from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention.

[0081] The embodiments described in this invention relate to a method for preparing carbon-supported high-entropy atom electrocatalysts using a molten lithium method. The electrocatalysts prepared by this method can be used for the electrocatalytic reduction of carbon dioxide (CO2RR) to valuable chemicals such as formic acid, acetic acid, and ethanol. The electrocatalysts prepared by this method can also be applied in water electrolysis for hydrogen production and oxygen reduction fuel cells. According to the embodiments, the catalysts exhibit high selectivity and stability for the reduction of carbon dioxide to hydrocarbons.

[0082] The following examples are provided for illustrative purposes and should not be considered as limiting the scope of the invention.

[0083] Example 1

[0084] This embodiment provides a method for preparing a carbon-supported Cu, Sn, In, Bi, Pt high-entropy catalyst with high selectivity and stability for ethanol. An electrocatalyst for CO2RR was prepared using a lithium melting method. The overall preparation process is as follows: Figure 1 As shown. The specific steps are as follows:

[0085] (1) The process was carried out in an argon glove box (oxygen level <0.3ppm) using a nickel crucible. 0.256 mol lithium (99.9%) was heated to 220°C and 0.019 mmol copper wire (99.9%), 0.019 mmol tin sheet (99.9%), 0.019 mmol indium wire (99.9%), 0.019 mmol bismuth block (99.9%) and 0.019 mmol platinum wire (99.9%) were added.

[0086] (2) A high-precision ultrasonic homogenizer was used to ensure uniform dispersion of metal atoms while the lithium melt was kept at 220°C for 1 hour. During the heating process, the liquid surface remained mirror-like and uniform. The ultrasonic action helped disperse large metal particles into individual atoms, preventing them from precipitating, re-aggregating, or depositing in the molten lithium.

[0087] (3) Quickly pour the molten liquid onto a clean stainless steel plate to form a solid solution.

[0088] (4) After the solid solution is cooled, the solid is taken out of the glove box, cut into small pieces, and lithium is slowly converted into LiOH in humid air.

[0089] (5) Mix the copper, indium, tin, bismuth, platinum atoms / LiOH material with the required amount of carbon black (Vulcan XC-72R) and mix with an agate mortar and pestle until homogeneous.

[0090] (6) LiOH was leached with a large amount of distilled water, leaving Cu, Sn, In, Bi, and Pt atoms embedded in the amorphous carbon support. The sample was vacuum dried at 100℃ for 24 h. Samples with different mass loadings were prepared on carbon black: Product 1: Carbon-loaded Cu, Sn, In, Bi, and Pt with a total catalytic metal mass fraction of 0.1% (0.1% refers to the mass fraction of the catalyst in the catalytic metal + catalyst support, and the same expression below has the same meaning, which will not be repeated here) or Product 2: Carbon-loaded Cu, Sn, In, Bi, and Pt with a total catalytic metal mass fraction of 0.4%.

[0091] (7) Drop 15 μL of electrocatalyst ink onto the RDE electrode. The ink was prepared by adding 5 mg of catalyst powder to 50 mg of Nafion (perfluorinated resin solution) and 200 mg of methanol. The electrode needs to be dried for 10 minutes before testing.

[0092] (8) At room temperature and atmospheric pressure, 30 mL of NaHCO3 was added to a 250 mL reactor with 0.149 mg of catalyst to determine the reaction rate and selectivity of CO2 reduction to prepare formic acid. Before the test, the electrolyte was purged with argon gas for 30 minutes to remove air from the environment. The electrolyte was then purified with CO2 for 30 minutes to fully saturate it and form a NaHCO3 buffer solution with a pH of 6.8.

[0093] The stability of the catalyst was determined using a time-amperometric method. The carbon-supported Cu, Sn, In, Bi, Pt catalyst with a total catalytic metal mass fraction of 0.1% remained stable for over 16 hours at -0.6 V. Specific results are shown below. Figure 3 As shown, the catalyst has a Faraday efficiency of 95% for formic acid at -0.6V and exceeds 90% throughout the stability test.

[0094] The NMR spectra of the products of a carbon-supported Cu, Sn, In, Bi, Pt catalyst with a total catalytic metal mass fraction of 0.1% are shown below. Figure 2 As shown.

[0095] Example 2

[0096] This embodiment provides a method for preparing a carbon-supported Sn, In, Cu, Ag, Ni high-entropy metal catalyst with high stability and high Faraday efficiency. The specific steps are as follows:

[0097] (1) A carbon-supported Sn, In, Cu, Ag, Ni high-entropy catalyst (Sn, In, Pd, Bi, Ni atomic ratio of 1:1:1:1:1) was prepared using the same preparation method as in Example 1. The total mass fraction of catalytic metal in the catalyst was 0.8%.

[0098] (2) The prepared sample, consisting of 5 mg of catalyst, was mixed with 50 mg of Nafion (perfluorinated resin solution) and 200 mg of methanol. The resulting solution was sonicated for 60 minutes to ensure sufficient dispersion of the electrocatalyst, and then deposited in 15 μL increments onto a rotating disk electrode (RDE) glassy carbon electrode, with each 5 μL deposition having a surface area of ​​0.196 cm². 2 .

[0099] (3) The above catalyst was tested in a carbon dioxide-saturated bicarbonate solution (pH 6.8) using a rotating disk electrode (RDE) at 1600 rpm, with an initial scan rate of 50 mV / s, from 0 to -1.5 V (compared to the standard hydrogen electrode), to ensure full-range carbon dioxide reduction activity. The results are as follows: Figure 4 As shown, the catalyst's onset potential under a carbon dioxide atmosphere is lower than that under an argon atmosphere, indicating that the catalyst has higher catalytic activity for carbon dioxide. Figure 5 As shown, the scan rate was increased from 10 mV to 100 mV / s in 10 mV intervals to evaluate the electrochemical active area of ​​the catalyst, which reached a high of 4.99 mF·cm⁻¹. -2 .

[0100] (4) Catalyst performance was studied using physicochemical characterization methods similar to those in Example 1. For a carbon-supported Sn, In, Cu, Ag, Ni high-entropy catalyst with a mass fraction of 0.8%, the results were as follows at an electrode polarization potential of -0.8V (compared to the standard hydrogen electrode): Figure 6 As shown, the catalyst has a stability of 20 h and a selectivity for acetic acid products (i.e., Faraday efficiency) close to 90%.

[0101] Example 3

[0102] This embodiment provides a method for preparing a carbon-supported Ir, Pd, Ru, Rh, Pt high-entropy atomically dispersed catalyst to reduce the overpotential of water splitting. The specific steps are as follows:

[0103] (1) Carbon-supported Ir, Pd, Ru, Rh, Pt high-entropy single-atom catalysts were prepared using the same method as in Example 1. The mass fraction of each catalytic metal in the catalyst was 0.2% (the molar ratio of catalytic metal atoms was 1:1:1:1:1).

[0104] (2) The prepared sample, consisting of 5 mg of catalyst, was mixed with 50 mg of Nafion (perfluorinated resin solution) and 200 mg of isopropanol. The resulting solution was sonicated for 60 minutes to ensure sufficient dispersion of the electrocatalyst, and 15 μL was deposited onto the gold electrode in stages. The water electrolysis reaction was then tested using RDE. The hydrogen evolution overpotential of the prepared metal was 0.502 V, while that of commercial iridium oxide was 0.579 V. It can be seen that the hydrogen evolution overpotential of the catalyst prepared in this invention is lower than that of commercial materials, indicating that its catalytic performance is improved.

[0105] Example 4

[0106] This embodiment provides a method for preparing a catalyst to improve the half-wave potential in an oxygen reduction fuel cell. The specific steps are as follows:

[0107] (1) A carbon-supported PtFeSnCuCo high-entropy atomic catalyst was prepared using the same method as in Example 1. The total mass fraction of metal on the catalytic substrate was 0.2% (the ratio of catalytic metal atoms was 1:1:1:1:1).

[0108] (2) The prepared sample, consisting of 5 mg of catalyst, was mixed with 50 mg of Nafion (perfluorinated resin solution) and 200 mg of isopropanol. The resulting solution was sonicated for 60 minutes to ensure sufficient dispersion of the electrocatalyst, and 15 μL was deposited in stages on a glassy carbon disk electrode and a Pt metal ring. The oxygen reduction reaction was then tested using RRDE.

[0109] (3) The catalyst of the present invention has advantages such as improved half-wave potential and active quality when applied in oxygen reduction fuel cells, and the prepared noble metal single-atom catalyst reduces the cost of using noble metal catalysts in fuel cells. According to the examples, the half-wave potential is shown to be 0.92V on the carbon-supported PtFeSnCuCo high-entropy single-atom catalyst.

[0110] Example 5

[0111] This embodiment provides a method for preparing a carbon-supported SnInPdFe high-entropy metal catalyst with high stability and high Faraday efficiency. The specific steps are as follows:

[0112] (1) A carbon-supported SnInPdFe high-entropy catalyst (Sn, In, Pd, Bi atomic ratio of 3:3:2:2) was prepared according to Example 1, with a total metal mass fraction of 0.12% on the catalyst substrate.

[0113] (2) The prepared sample, consisting of 5 mg of catalyst, was mixed with 50 mg of Nafion (perfluorinated resin solution) and 200 mg of methanol. The resulting solution was sonicated for 60 minutes to ensure sufficient dispersion of the electrocatalyst, and then deposited in 15 μL increments onto a rotating disk electrode (RDE) glassy carbon electrode, with each 5 μL deposition having a surface area of ​​0.196 cm². 2 .

[0114] (3) The catalyst performance was studied using a physicochemical characterization method similar to that in Example 1. For the carbon-supported SnInPdFe high-entropy catalyst with a mass fraction of 0.12%, the selectivity for acetic acid products was close to 90% at an electrode polarization potential of -0.6V (compared to the standard hydrogen electrode).

[0115] Comparative Example 1

[0116] It uses essentially the same method as Example 1, the only difference being that CuSnInBiPt is replaced by Cu with the same mass loaded on the catalyst.

[0117] Comparative Example 2

[0118] It uses essentially the same method as Example 1, the only difference being that Sn of the same mass is loaded onto the catalyst to replace CuSnInBiPt.

[0119] Comparative Example 3

[0120] It uses essentially the same method as Example 1, the only difference being that the same mass of In is loaded onto the catalyst to replace CuSnInBiPt.

[0121] Comparative Example 4

[0122] It uses essentially the same method as Example 1, the only difference being that the same mass of Bi is loaded onto the catalyst to replace CuSnInBiPt.

[0123] Comparative Example 5

[0124] It uses essentially the same method as Example 1, the only difference being that the same mass of Pt is loaded on the catalyst instead of CuSnInBiPt.

[0125] The catalysts prepared in Comparative Examples 1-5 were tested using the same method as in Example 1. The Faraday efficiency of the catalysts for formic acid at -0.6V is shown in Table 1.

[0126] Table 1. Faradaic efficiency of CO2 reduction of p-formic acid at -0.6 V for catalysts prepared in Comparative Examples 1-5.

[0127] Comparative Example Faraday efficiency (%) of formic acid Comparative Example 1 0.2 Comparative Example 2 82.1 Comparative Example 3 90.6 Comparative Example 4 88 Comparative Example 5 0

[0128] A comparison of the results of Example 1 and Comparative Examples 1-5 shows that the high-entropy catalyst prepared by the present invention can achieve the synergistic effect of multiple metals and can achieve synergistic response through structural adaptation and electronic conversion, thereby achieving high activity and selectivity of the catalyst.

[0129] Catalysts prepared in other embodiments of the present invention can also achieve synergistic effects of multiple metals, thereby improving the catalyst's high activity and selectivity.

[0130] It should be noted that the construction and arrangement of the various exemplary embodiments are merely illustrative. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art upon review of this disclosure will readily recognize that many modifications are possible (e.g., variations in the size, dimensions, structure, shape and proportions of various elements, parameter values, installation arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel doctrine and advantages of the subject matter described herein. Other substitutions, modifications, alterations, and omissions may be made to the design, operating conditions, and arrangements of the various exemplary embodiments without departing from the scope of the invention.

[0131] While this specification contains many specific implementation details, it should not be construed as a limitation on the scope or declarability of any invention, but rather as a specific description of the characteristics of a particular implementation of a particular invention. Some features described in this specification in the context of a single implementation may also be implemented in combination within a single implementation. Conversely, various features described in the context of a single implementation may also be implemented individually in multiple implementations or in any suitable sub-combination.

Claims

1. The application of an atomically controllable high-entropy catalyst as an electrocatalyst for the reduction of CO2 to formic acid, characterized in that, The atomically controllable high-entropy catalyst comprises a support and an active component; the active component consists of five metals: Cu, Sn, In, Bi, and Pt, in a molar ratio of 1:1:1:1:1; the metals in the active component are atomically dispersed on the support; the preparation method of the atomically controllable high-entropy catalyst includes the following steps: (1) Preparation of molten alkali metals under anhydrous and oxygen-free conditions; (2) Add the catalytic metal to the molten alkali metal to obtain a molten alkali metal-catalytic metal mixture; (3) After cooling the molten alkali metal-catalytic metal mixture, place it in a humid environment to obtain an alkali metal hydroxide-catalytic metal mixture; (4) The alkali metal hydroxide-catalytic metal mixture is mixed evenly with the catalyst support, and then the alkali metal hydroxide is removed and dried to obtain an atomically controllable high entropy catalyst.

2. The application of an atomically controllable high-entropy catalyst as an electrocatalyst for the reduction of CO2 to acetic acid, characterized in that, The atomically controllable high-entropy catalyst comprises a support and an active component; the active component consists of five metals: Sn, In, Cu, Ag, and Ni, in a molar ratio of 1:1:1:1:1; the metals in the active component are atomically dispersed on the support; the preparation method of the atomically controllable high-entropy catalyst includes the following steps: (1) Preparation of molten alkali metals under anhydrous and oxygen-free conditions; (2) Add the catalytic metal to the molten alkali metal to obtain a molten alkali metal-catalytic metal mixture; (3) After cooling the molten alkali metal-catalytic metal mixture, place it in a humid environment to obtain an alkali metal hydroxide-catalytic metal mixture; (4) The alkali metal hydroxide-catalytic metal mixture is mixed evenly with the catalyst support, and then the alkali metal hydroxide is removed and dried to obtain an atomically controllable high entropy catalyst.

3. The application according to claim 1 or 2, characterized in that, In step (1), the alkali metal in the molten alkali metal is selected from lithium, sodium, potassium, rubidium and cesium.

4. The application according to claim 1 or 2, characterized in that, In step (3), Cooling time ≤ 20 minutes; A humid environment is a humid air environment, with a relative humidity of 50% to 100%. The storage time is 24h to 72h.

5. The application according to claim 1 or 2, characterized in that, In step (4), the catalyst support is selected from a carbon support; and / or, In the catalyst, the mass ratio of catalytic metal to catalyst support is 0.01% to 10%; and / or, The method of achieving uniform mixing is mechanical mixing; and / or, The drying method is vacuum drying at 50-100℃.

6. The application according to claim 5, characterized in that, In step (4), the catalyst support is selected from one or more of carbon black, graphene, and carbon nanotubes; and / or, In the catalyst, the mass ratio of catalytic metal to catalyst support is 0.01% to 5%; and / or, Mechanical mixing is achieved by grinding to ensure uniform mixing.

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