A multi-component ruthenium nickel-based metal nanosheet and its preparation method and application

Abstract

This invention provides a multi-component ruthenium-nickel-based metal nanosheet, its preparation method, and its applications, relating to the field of catalyst technology. The invention provides a multi-component ruthenium-nickel-based metal nanosheet, which is a two-dimensional nanosheet with a core-shell structure. The core-shell structure includes a core metal element and a shell metal element. The core metal element includes nickel and an auxiliary metal element, which includes one or more of cobalt, copper, iron, and manganese. The shell metal element is ruthenium. The multi-component ruthenium-nickel-based metal nanosheet provided by this invention is highly efficient and stable, exhibiting excellent anodic hydroxide electrocatalytic performance in alkaline membrane fuel cells. This invention also provides a simple, feasible, and easily mass-producible method for preparing the multi-component ruthenium-nickel-based metal nanosheet.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, and in particular to a multi-component ruthenium-nickel based metal nanosheet, its preparation method, and its application. Background Technology

[0002] Alkaline membrane fuel cells (EMCs) are highly efficient and clean energy conversion devices that generate electricity through chemical reactions. Using anion exchange membranes, EMCs work by reacting hydrogen and oxygen in the presence of a catalyst to produce electricity and water. The energy density of EMCs is significantly higher than that of traditional fuel cells, giving them a clear advantage in energy efficiency.

[0003] However, the hydroxide reaction at the anode of alkaline membrane fuel cells still lacks an effective catalyst, making it difficult to meet commercial requirements for activity and stability. Currently, platinum catalysts are widely used for the hydroxide reaction at the anode of alkaline membrane fuel cells. However, in current industrial hydrogen production processes, a certain amount of CO is carried. Even after purification treatment, it is difficult to completely remove CO and it increases costs. This residual CO enters the battery with hydrogen, severely poisoning the Pt active sites of the platinum catalyst, resulting in poor catalyst activity and low stability. Constructing an anode hydroxide catalyst with good activity and stability is an urgent technical problem to be solved. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a multi-component ruthenium-nickel-based metal nanosheet, its preparation method, and its application. The multi-component ruthenium-nickel-based metal nanosheet provided by this invention is highly efficient and stable, and exhibits excellent anodic hydroxide electrocatalytic performance when applied to alkaline membrane fuel cells.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a multi-component ruthenium-nickel-based metal nanosheet, wherein the multi-component ruthenium-nickel-based metal nanosheet is a two-dimensional nanosheet with a core-shell structure; the core-shell structure includes a core metal element and a shell metal element, wherein the core metal element includes nickel and an auxiliary metal element, wherein the auxiliary metal element includes one or more of cobalt, copper, iron and manganese, and the shell metal element is ruthenium.

[0007] Preferably, the molar percentage of each metal element in the multi-component ruthenium-nickel-based metal nanosheet is independently 8-50%.

[0008] Preferably, the multi-component ruthenium-nickel-based metal nanosheets have a diameter of 8-15 nm, a total thickness of 1.5-2.5 nm, and a shell thickness of 1.2-1.7 nm.

[0009] This invention provides a method for preparing the multi-component ruthenium-nickel-based metal nanosheets, comprising the following steps:

[0010] A ruthenium source, a nickel source, a reducing agent, and a first organic solvent are mixed to carry out a first reduction reaction to obtain a first reaction solution;

[0011] An auxiliary metal precursor is mixed with a second organic solvent to obtain an auxiliary metal precursor dispersion; the auxiliary metal precursor includes one or more of a cobalt source, a copper source, an iron source, and a manganese source.

[0012] The auxiliary metal precursor dispersion is mixed with the first reaction solution to carry out a second reduction reaction to obtain the multi-component ruthenium-nickel-based metal nanosheets;

[0013] The temperature of the first reduction reaction and the second reduction reaction are independently 150~200℃, and the time is independently 150~200min.

[0014] Preferably, the ruthenium source includes dodecacarbonyltriruthenium or ruthenium acetylacetonate; the nickel source includes nickel acetylacetonate or nickel chloride; the cobalt source includes cobalt acetylacetonate or cobalt dichloride; the copper source includes copper acetylacetonate or copper chloride; the iron source includes iron acetylacetonate or iron chloride; and the manganese source includes manganese acetylacetonate or manganese chloride.

[0015] Preferably, the reducing agent includes one or more of glucose, ascorbic acid, and hexadecyltrimethylammonium chloride; the mass ratio of the reducing agent to the ruthenium source is 15~25:1.

[0016] Preferably, the first organic solvent and the second organic solvent independently comprise one or more of oleylamine, benzyl alcohol, and ethylene glycol.

[0017] Preferably, the mixing of the ruthenium source, nickel source, reducing agent and first organic solvent, as well as the mixing of the auxiliary metal precursor and second organic solvent, are all performed under ultrasonic conditions; the ultrasonic power is 60~100W and the time is 60~120min.

[0018] This invention provides the application of the multi-component ruthenium-nickel based metal nanosheets described in the above technical solutions or the multi-component ruthenium-nickel based metal nanosheets prepared by the above technical solutions as catalysts in the catalytic anode hydrogenation reaction of alkaline membrane fuel cells.

[0019] Preferably, the electrolyte for the anodic hydroxide reaction in the alkaline membrane fuel cell is a potassium hydroxide solution with a concentration of 0.05~0.2 mol / L.

[0020] This invention provides a multi-component ruthenium-nickel-based metal nanosheet, which has the following advantages compared with the prior art:

[0021] The multi-element ruthenium-nickel-based metal nanosheets provided by this invention have a core-shell structure. The core element can regulate the electronic structure of the shell through ligand effects and strain effects, thereby optimizing the catalytic reaction performance. The core element can adjust the electronic structure of the outer shell ruthenium and the adsorption energy of reaction intermediates, thereby improving the CO removal capacity (enhancing anti-poisoning performance) and improving the hydrogenation capacity. In addition, the core metal element includes nickel and auxiliary metal elements. With the increase of nuclear entropy, the lattice stability of the nanosheets will be stronger, which can further improve the stability.

[0022] The nanosheet structure of multi-component ruthenium-nickel-based metal nanosheets has a large specific surface area, which can provide more active sites, enabling it to fully contact reactants as a catalyst; and the two-dimensional structure of core-shell nanosheets can provide a shorter mass transfer path, reducing the diffusion resistance of reactants and products.

[0023] Therefore, the multi-component ruthenium-nickel based metal nanosheets provided by this invention are highly efficient and stable, and exhibit excellent anodic hydroxide electrocatalytic performance when applied to alkaline membrane fuel cells. Attached Figure Description

[0024] Figure 1 Transmission electron microscopy image of the ruthenium-nickel-cobalt core-shell nanosheets prepared in Example 1;

[0025] Figure 2 Transmission electron microscopy image of the ruthenium-nickel-iron-manganese core-shell nanosheets prepared in Example 3;

[0026] Figure 3 Aberration-corrected electron microscopy image of the ruthenium-nickel-cobalt-copper-iron-manganese core-shell nanosheets prepared in Example 4;

[0027] Figure 4 The oxidation reaction polarization curves of ruthenium nickel cobalt core-shell nanosheets (RuNiCo) prepared in Example 1 and ruthenium nickel cobalt copper iron manganese core-shell nanosheets (RuNiCoCuFeMn) prepared in Example 4 with commercial platinum carbon (Pt / C);

[0028] Figure 5 The lifetimes of Example 4 Ruthenium Nickel Cobalt Copper Iron Manganese Core-Shell Nanosheets (RuNiCoCuFeMn), Comparative Example 1 Ruthenium Nickel Metal Nanosheets (RuNi) and Commercial Platinum Carbon (Pt / C) were measured under a constant voltage (0.1V) in a CO and hydrogen atmosphere (CO content 1000ppm). Detailed Implementation

[0029] This invention provides a multi-component ruthenium-nickel-based metal nanosheet, wherein the multi-component ruthenium-nickel-based metal nanosheet is a two-dimensional nanosheet with a core-shell structure; the core-shell structure includes a core metal element and a shell metal element, wherein the core metal element includes nickel and an auxiliary metal element, wherein the auxiliary metal element includes one or more of cobalt, copper, iron and manganese, and the shell metal element is ruthenium.

[0030] In this invention, when the auxiliary metal element includes one of cobalt, copper, iron, and manganese, the resulting multi-component ruthenium-nickel-based metal nanosheets are binary low-entropy nanosheets (relative to the core metal element); when the auxiliary metal element includes two of cobalt, copper, iron, and manganese, the resulting multi-component ruthenium-nickel-based metal nanosheets are ternary medium-entropy core-shell nanosheets; when the auxiliary metal element includes three of cobalt, copper, iron, and manganese, the resulting multi-component ruthenium-nickel-based metal nanosheets are quaternary high-entropy core-shell nanosheets; and when the auxiliary metal element includes four of cobalt, copper, iron, and manganese, the resulting multi-component ruthenium-nickel-based metal nanosheets are pentagonal high-entropy core-shell nanosheets. In this invention, the shell metal element, i.e., ruthenium, exists in elemental form; the core metal element exists in alloy form, forming a polymetallic core.

[0031] This invention employs nickel and the aforementioned auxiliary metal elements as the core metal elements in the core-shell structure. These metal elements themselves possess excellent electrical conductivity and contain a large number of freely moving electrons. These electrons can move directionally under the influence of an electric field, forming an electric current and thus creating a good electron conduction channel. This invention employs ruthenium as the shell metal element in the core-shell structure. Ruthenium has strong anti-toxicity properties and is less expensive than Pt catalysts; however, ruthenium alone lacks sufficient activity. By forming a core-shell structure, the core element modulates the electronic structure of the outer shell ruthenium element and the adsorption energy of the reaction intermediates, thereby improving the CO removal capacity and the hydrogenation capacity. Furthermore, as the nuclear entropy increases, the lattice stability of the nanosheets becomes stronger, further improving stability. Simultaneously, the core element and the shell element are bonded together through chemical bonds or other interactions, allowing for a tight core-shell bond and also sharing some of the external forces.

[0032] In this invention, the molar percentage of each metal element in the multi-component ruthenium-nickel-based metal nanosheet is preferably 8-50% independently, and can be 8%, 9%, 10%, 12%, 13%, 14%, 17%, 20%, 21%, 22%, 23%, 28%, 30%, 31%, 32%, 35%, 40%, 41%, 46%, or 48%.

[0033] In this invention, the diameter of the multi-component ruthenium-nickel-based metal nanosheets is preferably 8-15 nm, and can be 8, 9, 10, 11, 12, 13, 14, or 15 nm; the total thickness is preferably 1.5-2.5 nm, and can be 1.5, 2, or 2.5 nm; and the shell thickness is preferably 1.2-1.7 nm, and can be 1.2, 1.3, 1.4, 1.5, 1.6, or 1.7 nm. By controlling the diameter, total thickness, and shell thickness of the multi-component ruthenium-nickel-based metal nanosheets within the above ranges, this invention facilitates the increase of active sites, optimizes the mass transfer process, and improves electron conduction efficiency, thereby enhancing catalytic activity. Simultaneously, it also enhances structural stability and improves resistance to poisoning.

[0034] The multi-component ruthenium-nickel-based metal nanosheets provided by this invention possess a core-shell structure. The core element can modulate the electronic structure of the shell through ligand effects and strain effects, thereby optimizing catalytic reaction performance. Furthermore, the core-shell structure of the nanosheets can protect the internal active components, preventing them from being oxidized, dissolved, or agglomerated during the reaction. The outer shell can block the external environment from eroding the core, while also inhibiting the grain growth and agglomeration of the core material. Simultaneously, the nanosheet structure of the multi-component ruthenium-nickel-based metal nanosheets has a large specific surface area, providing more active sites and enabling sufficient contact between the catalyst and reactants. Moreover, the two-dimensional structure of the core-shell nanosheets can provide a shorter mass transfer path, reducing the diffusion resistance of reactants and products.

[0035] This invention provides a method for preparing the multi-component ruthenium-nickel-based metal nanosheets described above, comprising the following steps:

[0036] A ruthenium source, a nickel source, a reducing agent, and a first organic solvent are mixed to carry out a first reduction reaction to obtain a first reaction solution;

[0037] An auxiliary metal precursor is mixed with a second organic solvent to obtain an auxiliary metal precursor dispersion; the auxiliary metal precursor includes one or more of a cobalt source, a copper source, an iron source, and a manganese source.

[0038] The auxiliary metal precursor dispersion is mixed with the first reaction solution to carry out a second reduction reaction, thereby obtaining the multi-component ruthenium-nickel-based metal nanosheets.

[0039] Unless otherwise specified, all raw materials involved in this invention are commercially available products well known to those skilled in the art.

[0040] The present invention mixes a ruthenium source, a nickel source, a reducing agent and a first organic solvent to carry out a first reduction reaction to obtain a first reaction solution.

[0041] In this invention, the ruthenium source preferably includes dodecyltriruthenium or ruthenium acetylacetonate; the nickel source preferably includes nickel acetylacetonate or nickel chloride; the reducing agent preferably includes one or more of glucose, ascorbic acid and hexadecyltrimethylammonium chloride; and the first organic solvent preferably includes one or more of oleylamine, benzyl alcohol and ethylene glycol.

[0042] In this invention, the mixing of the ruthenium source, nickel source, reducing agent, and first organic solvent is preferably carried out under ultrasonic conditions; the ultrasonic power is preferably 60-100W, but can be 70, 80, 90, or 100W, and the time is preferably 60-120min, but can be 60, 70, 80, or 100min; the mixing yields a turbid and uniform colloidal dispersion (or colloidal precursor dispersion). In this invention, the concentration of the ruthenium source in the colloidal dispersion is preferably 0.7-1.3 mg / mL, the concentration of the nickel source is preferably 0.5-1 mg / mL, and the mass ratio of the reducing agent to the ruthenium source is preferably 15-25:1, but can be 20:1.

[0043] In this invention, the temperature of the first reduction reaction is 150~200℃, which can be 160, 170, 180 or 190℃, and the time is 150~200min, which can be 160, 170, 180 or 190min. Preferably, the colloidal dispersion is transferred to an oil bath for heating, and after the colloidal dispersion is heated to 150~200℃, the temperature is maintained to carry out the first reduction reaction.

[0044] In the first reduction reaction, the nickel source first receives electrons from the reducing agent and undergoes a reduction reaction to form nanosheets. Subsequently, driven by temperature and time, ruthenium gradually grows on the nickel nanosheets, thereby forming Ni@Ru core-shell nanosheets. In this invention, the first reaction solution is a black colloidal dispersion.

[0045] The present invention mixes an auxiliary metal precursor and a second organic solvent to obtain an auxiliary metal precursor dispersion.

[0046] In this invention, the auxiliary metal precursor includes one or more of a cobalt source, a copper source, an iron source, and a manganese source; the cobalt source preferably includes cobalt acetylacetonate or cobalt dichloride; the copper source preferably includes copper acetylacetonate or copper chloride; the iron source preferably includes iron acetylacetonate or ferric chloride; and the manganese source preferably includes manganese acetylacetonate or manganese chloride. In this invention, the second organic solvent preferably includes one or more of oleylamine, benzyl alcohol, and ethylene glycol.

[0047] In this invention, the mixing of the auxiliary metal precursor and the second organic solvent is preferably carried out under ultrasonic conditions; the ultrasonic power is preferably 60-100W, which can be 60, 70, 80, 90 or 100W, and the time is preferably 60-120min, which can be 60, 70, 80, 90 or 100min. In this invention, the concentration of each metal element in the auxiliary metal precursor dispersion is preferably 0.1mg / mL. In this invention, the auxiliary metal precursor dispersion is a turbid and uniform colloidal dispersion (or colloidal precursor dispersion).

[0048] After obtaining the auxiliary metal precursor dispersion and the first reaction solution, the present invention mixes the auxiliary metal precursor dispersion and the first reaction solution to carry out a second reduction reaction to obtain the multi-component ruthenium-nickel-based metal nanosheets.

[0049] In this invention, the volume ratio of the auxiliary metal precursor dispersion to the first reaction solution is preferably 1:10.

[0050] In this invention, the temperature of the second reduction reaction is preferably 150-200°C, but can be 160, 170, 180, or 190°C, and the time is preferably 150-200 min, but can be 160, 170, 180, or 190 min. Preferably, the auxiliary metal precursor dispersion is added to the first reaction solution, mixed evenly, and then the resulting mixed dispersion is transferred to an oil bath for heating. After the mixed dispersion is heated to 150-200°C, it is kept at this temperature to carry out the second reduction reaction.

[0051] In the second reduction process, auxiliary metal elements continue to be reduced on the Ni@Ru core-shell nanosheets. Driven by temperature and time, they diffuse inward to form the final multi-component core-shell nanosheets. In both the first and second reduction processes, the formation of the core-shell structure is mainly related to the element diffusion properties. Driven by temperature and time, non-noble elements tend to diffuse inward, while noble metals diffuse outward. The subsequently added non-noble auxiliary metal grows on the initially formed Ni@Ru nanosheets, and diffuses inward with increasing temperature and time.

[0052] Following the second reduction reaction, the present invention preferably centrifuges and washes the resulting reaction solution (black colloidal dispersion) to obtain the multi-component ruthenium-nickel-based metal nanosheets. In the present invention, the centrifugation and washing operation is preferably performed by adding ethanol to the reaction solution after it has cooled to room temperature, followed by centrifugation; the ethanol serves to separate the precipitated product and remove any impurities that may be present on the product surface; the centrifugation speed can be 1500~3000 r / min, and the time can be 3~7 min.

[0053] Multicomponent alloy catalysts often exhibit superior performance compared to single-component materials due to the synergistic effects among their constituent elements. Different elements can promote different steps in the reaction or enhance catalytic activity by altering the electron cloud density of active sites through electronic interactions. Furthermore, core-shell structures allow for precise control of the catalyst's surface properties and electronic structure by adjusting the thickness, composition, and structure of the core and shell, thereby optimizing its catalytic activity and selectivity for specific reactions. Additionally, nanosheet structures possess a large specific surface area, providing more active sites and increasing the contact area between the catalyst and reactants, allowing for more complete exposure of active sites and facilitating reactant adsorption and product desorption. Therefore, designing multicomponent core-shell nanosheet materials provides a new research direction for constructing highly efficient and stable anodic hydroxide catalysts. However, finding a simple method to prepare multicomponent core-shell nanosheet materials with controllable structure and composition remains a significant challenge. This invention is based on a wet chemical organic phase preparation method. A ruthenium source, a nickel source, and a reducing agent are dissolved in an organic solvent. After heating to obtain a stable structure, an auxiliary metal element is dissolved in the organic solvent and added to the already stable solution, followed by further heating to prepare multi-component ruthenium-nickel-based metal nanosheets (multi-component ruthenium-nickel-based core-shell nanosheets). This invention provides a simple and feasible method for preparing multi-component ruthenium-nickel-based metal nanosheets with highly efficient and stable catalytic performance. The conditions are mild, the operation is simple, and it is easy to mass-produce, making it better suited for commercial applications. Furthermore, the elemental composition (such as the elements and their content and proportion in different parts of the shell) and microstructure (such as the thickness and diameter of the core-shell nanosheets) of the multi-component ruthenium-nickel-based metal nanosheets are controllable. By controlling the types of core-shell elements, the concentration of the reducing agent, the reaction temperature, and the reaction time, the reaction kinetics of the multi-component ruthenium-nickel-based core-shell nanosheet formation process can be precisely controlled, making the microstructure of the multi-component ruthenium-nickel-based metal nanosheets controllable. This has significant implications for the research of low-temperature multi-metal alloys.

[0054] This invention provides the application of multi-component ruthenium-nickel-based metal nanosheets, as described in the above technical solutions or prepared by the above methods, as catalysts in the anodic hydroxide reaction of alkaline membrane fuel cells. This invention does not impose any particular requirements on the alkaline membrane fuel cell; any alkaline membrane fuel cell well-known to those skilled in the art is applicable. In this invention, the electrolyte of the alkaline membrane fuel cell is preferably a potassium hydroxide solution, and the concentration of the potassium hydroxide solution is preferably 0.05~0.2 mol / L, which can be 0.05, 0.1, or 0.2 mol / L. The multi-component ruthenium-nickel-based metal nanosheets provided by this invention are highly efficient and stable, possess good resistance to CO poisoning, and exhibit excellent anodic hydroxide electrocatalytic performance when applied to alkaline membrane fuel cells.

[0055] To further illustrate the present invention, the following detailed description, in conjunction with examples, of the multi-component ruthenium-nickel-based metal nanosheets, their preparation methods, and applications provided by the present invention, should not be construed as limiting the scope of protection of the present invention.

[0056] Example 1

[0057] The preparation steps of multi-component ruthenium-nickel-based metal nanosheets (ruthenium-nickel-cobalt core-shell nanosheets) are as follows:

[0058] (1) Disperse dodecyltriruthenium, nickel acetylacetonate, and glucose in oleylamine at concentrations of 1 mg / mL, 0.5 mg / mL, and 20 mg / mL, respectively, and sonicate (sonication power of 80 W) for 80 min to obtain a turbid and uniform colloidal precursor dispersion.

[0059] (2) Transfer the gel-like precursor dispersion obtained in step (1) to an oil bath for oil bath heating. Heat to 170°C and keep warm for a total of 180 min to obtain a black gel-like dispersion. Then stop heating and take it out for use.

[0060] (3) Cobalt dichloride was dispersed in oleylamine at a concentration of 0.1 mg / mL and sonicated (sonication power of 80 W) for 80 min to obtain a turbid and uniform colloidal precursor dispersion.

[0061] (4) Add 1 mL of the turbid and uniform colloidal precursor dispersion obtained in step (3) to 10 mL of the black colloidal dispersion taken out in step (2) and mix evenly to obtain a black colloidal mixed dispersion.

[0062] (5) The black colloidal dispersion obtained in step (4) was transferred to an oil bath and heated to 170°C for 180 min. Heating was then stopped, and after the reaction vessel cooled to room temperature, 3 mL of ethanol was added to the resulting black colloidal dispersion. The mixture was then centrifuged at 3000 r / min for 3 min to obtain ruthenium nickel cobalt core-shell nanosheets (denoted as RuNiCo) with a diameter of 8 nm, a total thickness of 2 nm, and a shell thickness of 1.5 nm. The molar percentages of each metal element in the ruthenium nickel cobalt core-shell nanosheets were: Ru 48%, Ni 31%, and Co 21%.

[0063] Example 2

[0064] The preparation steps of multi-component ruthenium-nickel based metal nanosheets (ruthenium-nickel-copper core-shell nanosheets) are as follows:

[0065] (1) Disperse ruthenium acetylacetonate, nickel acetylacetonate, and ascorbic acid in ethylene glycol at concentrations of 1 mg / mL, 0.5 mg / mL, and 20 mg / mL, respectively, and sonicate (sonic power of 90 W) for 70 min to obtain a turbid and uniform colloidal precursor dispersion.

[0066] (2) Transfer the gel-like precursor dispersion obtained in step (1) to an oil bath for oil bath heating. Heat to 170°C and keep warm for a total of 180 min to obtain a black gel-like dispersion. Then stop heating and take it out for use.

[0067] (3) Copper acetylacetone was dispersed in ethylene glycol at a concentration of 0.1 mg / mL and sonicated (ultrasonic power of 90 W) for 70 min to obtain a turbid and uniform colloidal precursor dispersion.

[0068] (4) Add 1 mL of the turbid and uniform colloidal precursor dispersion obtained in step (3) to 10 mL of the black colloidal dispersion taken out in step (2) and mix evenly to obtain a black colloidal mixed dispersion.

[0069] (5) The black colloidal dispersion obtained in step (4) was transferred to an oil bath and heated to 170°C for a total holding time of 180 min. Heating was then stopped, and after the reaction vessel cooled to room temperature, 3 mL of ethanol was added to the obtained black colloidal dispersion. The mixture was then centrifuged at 2500 r / min for 3 min to obtain ruthenium-nickel-copper core-shell nanosheets (denoted as RuNiCu), with a diameter of 8 nm, a total thickness of 2 nm, and a shell thickness of 1.5 nm. The molar percentage of each metal element in the ruthenium-nickel-copper core-shell nanosheets was: Ru 46%, Ni 32%, and Cu 22%.

[0070] Example 3

[0071] The preparation steps of multi-component ruthenium-nickel-based metal nanosheets (ruthenium-nickel-iron-manganese core-shell nanosheets) are as follows:

[0072] (1) Disperse dodecyltriruthenium, nickel chloride, and hexadecyltrimethylammonium chloride in oleylamine at concentrations of 1 mg / mL, 0.5 mg / mL, and 20 mg / mL, respectively, and sonicate (sonication power of 100W) for 60 min to obtain a turbid and uniform colloidal precursor dispersion.

[0073] (2) Transfer the gel-like precursor dispersion obtained in step (1) to an oil bath for oil bath heating. Heat to 170°C and keep warm for a total of 180 min to obtain a black gel-like dispersion. Then stop heating and take it out for use.

[0074] (3) Disperse ferric chloride and manganese chloride in oleylamine at a concentration of 0.1 mg / mL and sonicate (sonication power of 100W) for 60 min to obtain a turbid and uniform colloidal precursor dispersion.

[0075] (4) Add 1 mL of the turbid and uniform colloidal precursor dispersion obtained in step (3) to 10 mL of the black colloidal dispersion taken out in step (2) and mix evenly to obtain a black colloidal mixed dispersion.

[0076] (5) The black colloidal mixed dispersion obtained in step (4) was transferred to an oil bath and heated to 170°C for a total holding time of 180 min. Then, the heating was stopped, and after the reaction vessel cooled to room temperature, 3 mL of ethanol was added to the obtained black colloidal dispersion. Subsequently, the mixture was centrifuged at 2500 r / min for 3 min to obtain ruthenium-nickel-iron-manganese core-shell nanosheets (denoted as RuNiFeMn), with a diameter of 8 nm, a total thickness of 2 nm, and a shell thickness of 1.5 nm. The molar percentage of each metal element in the ruthenium-nickel-iron-manganese core-shell nanosheets was: Ru 41%, Ni 28%, Fe 17%, and Mn 14%.

[0077] Example 4

[0078] The preparation steps of multi-component ruthenium-nickel-based metal nanosheets (ruthenium-nickel-cobalt-copper-iron-manganese core-shell nanosheets) are as follows:

[0079] (1) Disperse ruthenium acetylacetonate, nickel chloride, and hexadecyltrimethylammonium chloride in benzyl alcohol at concentrations of 1 mg / mL, 0.5 mg / mL, and 20 mg / mL, respectively, and sonicate (sonic power of 100W) for 60 min to obtain a turbid and uniform colloidal precursor dispersion.

[0080] (2) Transfer the gel-like precursor dispersion obtained in step (1) to an oil bath for oil bath heating. Heat to 170°C and keep warm for a total of 180 min to obtain a black gel-like dispersion. Then stop heating and take it out for use.

[0081] (3) Cobalt chloride, copper chloride, ferric chloride and manganese chloride were dispersed in benzyl alcohol at a concentration of 0.1 mg / mL and sonicated (sonication power of 100W) for 60 min to obtain a turbid and uniform colloidal precursor dispersion.

[0082] (4) Add 1 mL of the turbid and uniform colloidal precursor dispersion obtained in step (3) to 10 mL of the black colloidal dispersion taken out in step (2) and mix well to obtain a black colloidal mixed dispersion.

[0083] (5) The black colloidal mixed dispersion obtained in step (4) was transferred to an oil bath and heated to 170°C for a total holding time of 180 min. Then, the heating was stopped, and after the reaction vessel cooled to room temperature, 3 mL of ethanol was added to the obtained black colloidal dispersion. Subsequently, the mixture was centrifuged at 2500 r / min for 3 min to obtain ruthenium-nickel-cobalt-copper-iron-manganese core-shell nanosheets (denoted as RuNiCoCuFeMn), with a diameter of 8 nm, a total thickness of 2 nm, and a shell thickness of 1.5 nm. The molar percentage of each metal element in the ruthenium-nickel-cobalt-copper-iron-manganese core-shell nanosheets was: Ru 35%, Ni 23%, Co 12%, Cu 13%, Fe 9%, and Mn 8%.

[0084] Comparative Example 1

[0085] The preparation steps of ruthenium-nickel metal nanosheets are as follows:

[0086] (1) Disperse dodecyltriruthenium, nickel acetylacetonate, and glucose in oleylamine at concentrations of 1 mg / mL, 0.5 mg / mL, and 20 mg / mL, respectively, and sonicate (sonication power of 80 W) for 80 min to obtain a turbid and uniform colloidal precursor dispersion.

[0087] (2) The gel-like precursor dispersion obtained in step (1) was transferred to an oil bath and heated to 170°C. The temperature was kept for a total of 180 min to obtain a black gel-like dispersion. Then, the heating was stopped and the reaction vessel was cooled to room temperature. Ethanol was added to the obtained black gel-like dispersion and then centrifuged at 3000 r / min for 3 min to obtain ruthenium nickel metal nanosheets (denoted as RuNi).

[0088] Figure 1 This is a transmission electron microscope (TEM) image of the ruthenium-nickel-cobalt core-shell nanosheets prepared in Example 1. Figure 2 Transmission electron microscopy (TEM) image of the ruthenium-nickel-iron-manganese core-shell nanosheets prepared in Example 3. Figure 1 and Figure 2 The morphology and structural features of the core-shell nanosheets are shown. They have a nanometer-sized thickness and a two-dimensional nanosheet morphology with a thickness of approximately 2 nm. Figure 3 The image shown is a spherical aberration electron microscope image of the ruthenium-nickel-cobalt-copper-iron-manganese core-shell nanosheets prepared in Example 4. It can be seen that the core-shell nanosheets have been formed, and ruthenium acts as the shell element to encapsulate the core structure formed by nickel and auxiliary metals.

[0089] Figure 4The polarization curves of the hydroxide reaction between ruthenium nickel cobalt core-shell nanosheets (RuNiCo) prepared in Example 1, ruthenium nickel cobalt copper iron manganese core-shell nanosheets (RuNiCoCuFeMn) prepared in Example 4, and commercial platinum carbon (Pt / C) are shown. The curves were tested under the conditions of a scan rate of 5 mV / s, a rotation speed of 1600 r / min, and pure hydrogen gas. A three-electrode system was used for the test, with the electrode supporting the catalyst (ruthenium nickel cobalt core-shell nanosheets prepared in Example 1, ruthenium nickel cobalt copper iron manganese core-shell nanosheets prepared in Example 4, or commercial platinum carbon) as the working electrode, a carbon rod as the counter electrode, and a saturated calomel electrode as the reference electrode. The electrolyte was a 0.1 mol / L potassium hydroxide solution. Figure 4 The curves shown indicate that when ruthenium-nickel-cobalt core-shell nanosheets are used as catalysts, the anolyte current increases sharply with the increase of potential, indicating that it has high alkaline membrane hydrogenation catalytic performance, which is higher than that of commercial platinum-carbon. The ruthenium-nickel-cobalt-copper-iron-manganese core-shell nanosheets can rapidly rise to a very large current at a very small potential, indicating that the catalyst readily undergoes the hydrogenation reaction.

[0090] Figure 5 The lifetimes of Example 4 (RuNiCoCuFeMn), Comparative Example 1 (RuNi), and commercial platinum-carbon (Pt / C) nanosheets were measured under a constant voltage (0.1V) in a CO and hydrogen atmosphere (CO concentration 1000ppm). Figure 5 It can be seen that under a constant potential of 0.1V, the performance of commercial platinum carbon (Pt / C) remained at 19.4% of its initial performance after 2 hours, while the performance of comparative example 1 ruthenium nickel metal nanosheets (RuNi) remained at 30.7% of its initial performance after 2 hours. However, the performance of RuNiCoCuFeMn only decreased by 9.9% after 6 hours, indicating that in terms of anti-poisoning performance, ruthenium nickel-based core-shell nanosheets are superior to comparative ruthenium nickel metal nanosheets and commercial platinum carbon, and have better stability.

[0091] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A multi-component ruthenium-nickel based metal nanosheet, characterized in that, The multi-component ruthenium-nickel-based metal nanosheets are two-dimensional nanosheets with a core-shell structure; the core-shell structure includes a core metal element and a shell metal element, the core metal element is composed of nickel and an auxiliary metal element, the auxiliary metal element is one or more of cobalt, copper, iron and manganese, and the shell metal element is ruthenium; The molar percentage of each metal element in the multi-component ruthenium-nickel-based metal nanosheets is independently 8% to 50%. The multi-component ruthenium-nickel-based metal nanosheets have a diameter of 8-15 nm, a total thickness of 1.5-2.5 nm, and a shell thickness of 1.2-1.7 nm. The preparation method of the multi-component ruthenium-nickel-based metal nanosheets includes the following steps: A ruthenium source, a nickel source, a reducing agent, and a first organic solvent are mixed to carry out a first reduction reaction to obtain a first reaction solution; An auxiliary metal precursor is mixed with a second organic solvent to obtain an auxiliary metal precursor dispersion; the auxiliary metal precursor includes one or more of a cobalt source, a copper source, an iron source, and a manganese source. The auxiliary metal precursor dispersion is mixed with the first reaction solution to carry out a second reduction reaction to obtain the multi-component ruthenium-nickel-based metal nanosheets; The temperature of the first reduction reaction and the second reduction reaction are independently 150~200℃, and the time is independently 150~200min.

2. The method for preparing the multi-component ruthenium-nickel based metal nanosheets according to claim 1, characterized in that, Includes the following steps: A ruthenium source, a nickel source, a reducing agent, and a first organic solvent are mixed to carry out a first reduction reaction to obtain a first reaction solution; An auxiliary metal precursor is mixed with a second organic solvent to obtain an auxiliary metal precursor dispersion; the auxiliary metal precursor includes one or more of a cobalt source, a copper source, an iron source, and a manganese source. The auxiliary metal precursor dispersion was mixed with the first reaction solution to carry out a second reduction reaction, thereby obtaining the multi-component ruthenium-nickel-based metal nanosheets. The temperature of the first reduction reaction and the second reduction reaction are independently 150~200℃, and the time is independently 150~200min.

3. The preparation method according to claim 2, characterized in that, The ruthenium source includes ruthenium dodecyltriruthenium or ruthenium acetylacetonate; the nickel source includes nickel acetylacetonate or nickel chloride; the cobalt source includes cobalt acetylacetonate or cobalt dichloride; the copper source includes copper acetylacetonate or copper chloride; the iron source includes iron acetylacetonate or iron chloride; and the manganese source includes manganese acetylacetonate or manganese chloride.

4. The preparation method according to claim 2 or 3, characterized in that, The reducing agent includes one or more of glucose, ascorbic acid, and hexadecyltrimethylammonium chloride; the mass ratio of the reducing agent to the ruthenium source is 15~25:

1.

5. The preparation method according to claim 2, characterized in that, The first organic solvent and the second organic solvent independently include one or more of oleylamine, benzyl alcohol, and ethylene glycol.

6. The preparation method according to claim 2, characterized in that, The mixing of the ruthenium source, nickel source, reducing agent, and first organic solvent, as well as the mixing of the auxiliary metal precursor and second organic solvent, are all performed under ultrasonic conditions; the ultrasonic power is 60~100W, and the time is 60~120min.

7. The application of the multi-component ruthenium-nickel based metal nanosheets of claim 1 or the multi-component ruthenium-nickel based metal nanosheets prepared by any one of claims 2 to 6 as a catalyst in the catalytic anode hydrogenation reaction of an alkaline membrane fuel cell.

8. The application according to claim 7, characterized in that, The electrolyte for the anodic hydroxide reaction in the alkaline membrane fuel cell is a potassium hydroxide solution with a concentration of 0.05~0.2 mol / L.

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