Alloy nano-cluster electrocatalyst and preparation method thereof
By using silicon carbide or alumina as template agents in the preparation of nano alloy electrocatalysts and using discharge plasma heating alloying technology, the problem of easy agglomeration of nano-alloy electrocatalysts in high temperature environments is solved, and the nanoscale alloy nanocluster particles are maintained and uniformly dispersed, simplifying the preparation process and reducing costs.
Patent Information
- Application Number
- CN202510201127.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-24
- Publication Date
- 2025-06-10
AI Technical Summary
Nanoalloy electrocatalysts are prone to agglomeration into larger particles under high temperature environments, the preparation process is complex and the single yield is low, resulting in high preparation costs and hindering industrialization and commercialization.
Silicon carbide or alumina is used as template agents to alloy the electrocatalyst precursor of cobalt-based alloy nanocluster electrocatalyst, which effectively limits the aggregation and growth of alloy nanoclusters, so that they are kept at the nanoscale and evenly dispersed.
The nanoscale maintenance and uniform dispersion of alloy nanocluster particles is achieved, the preparation process is simplified, the preparation cost is reduced, the catalytic effect is good, and it is conducive to industrial preparation.
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Figure CN120127156A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of electrocatalysts, and particularly relates to an alloy nanocluster electrocatalyst and a preparation method thereof. Background Art
[0002] As an important means to reduce the reaction energy barrier and production cost, catalysis technology has become the pillar of modern industry, environment and energy, and has always been the focus of current scientific research. Developing efficient, inexpensive and stable catalysts is a long-term goal. Nanoalloy catalysts are an important type of catalyst. However, due to the wide adjustability of their element types and ratios, the adsorption energy is almost continuously distributed. By adjusting the composition and ratio of elements in the nanoalloy catalyst, the optimal adsorption strength can be obtained, thereby maximizing its catalytic activity, such as hydrogen evolution, oxygen evolution, oxygen reduction, etc.
[0003] The preparation of nanoalloy catalysts usually includes flash Joule heating method, fast moving bed pyrolysis method, dealloying method, solvothermal synthesis method, ultrasonic-assisted wet chemical method, etc. However, these methods usually require strict control of preparation conditions, and the alloy particles are prone to agglomeration and growth. There are at least the following problems:
[0004] In the preparation process of nanoalloy electrocatalysts, especially in a high-temperature environment, the liquid-phase alloy tends to agglomerate into larger particles under the action of surface tension, resulting in the aggregation of alloy particles;
[0005] The preparation process usually requires strict control of preparation conditions, such as the need to use a carrier, multiple temperature increases, treatment with corrosive chemicals, etc., resulting in a complex preparation process;
[0006] The single-pass yield is low, and batch preparation cannot be achieved, making the preparation cost high, which becomes a great obstacle to industrialization and commercialization. Summary of the Invention
[0007] In view of this, on the one hand, some embodiments disclose a preparation method of an alloy nanocluster electrocatalyst, including the steps of:
[0008] S1. Using an organic ligand, a surface capping agent, and a transition metal cobalt salt to prepare a cobalt-based metal covalent organic framework material precursor;
[0009] S2. Mixing the cobalt-based metal covalent organic framework material precursor with other transition metal salts to obtain a cobalt-based alloy nanocluster electrocatalyst precursor; the other transition metal salts include iron, nickel, manganese, tungsten, molybdenum, vanadium or chromium salts, excluding cobalt salts; the molar ratio of the other transition metal salts to the transition metal cobalt salt is 1:1;
[0010] S3. Mix the cobalt-based alloy nanocluster electrocatalyst precursor with a templating agent to obtain a raw material mixture; the templating agent is micron-scale silicon carbide / aluminum oxide, and the mass ratio of the templating agent to the cobalt-based alloy nanocluster electrocatalyst precursor is 3:1;
[0011] S4. Alloying is carried out on the raw material mixture under the heating of a discharge plasma to generate an alloy nanocluster electrocatalyst product;
[0012] S5. Purify and separate the alloy nanocluster electrocatalyst product to remove the templating agent and obtain the alloy nanocluster electrocatalyst.
[0013] Furthermore, in the preparation method of the alloy nanocluster electrocatalyst disclosed in some embodiments, the organic ligand is dimethylimidazole.
[0014] In the preparation method of the alloy nanocluster electrocatalyst disclosed in some embodiments, the surface capping agent is cetyltrimethylammonium bromide.
[0015] In the preparation method of the alloy nanocluster electrocatalyst disclosed in some embodiments, in step S1, the preparation method of the cobalt-based metal covalent organic framework material precursor includes:
[0016] Dissolve the organic ligand in deionized water to obtain an organic ligand solution;
[0017] Add the surface capping agent to the organic ligand solution and stir;
[0018] Add the transition metal salt solution and continue to stir;
[0019] Centrifuge to collect the precipitate, wash it, and thus obtain the cobalt-based metal covalent organic framework material precursor.
[0020] In the preparation method of the alloy nanocluster electrocatalyst disclosed in some embodiments, in step S2, the preparation method of the cobalt-based alloy nanocluster electrocatalyst precursor includes:
[0021] Disperse the cobalt-based metal covalent organic framework material precursor in deionized water, and add other transition metal salts in an equimolar ratio to the cobalt-based metal covalent organic framework material precursor; stir at room temperature;
[0022] Collect the precipitate, wash it, and dry it to obtain the cobalt-based alloy nanocluster electrocatalyst precursor.
[0023] In the preparation method of the alloy nanocluster electrocatalyst disclosed in some embodiments, in step S4, the conditions of the discharge plasma heating include: a vacuum environment, a pressure of 10 - 40 Mpa, a heating temperature of 800 - 1200 °C, and a holding time of not more than 30 min.
[0024] In the preparation method of the alloy nanocluster electrocatalyst disclosed in some embodiments, in step S5, the purification and separation method includes:
[0025] The alloy nanocluster electrocatalyst product is ground and then ultrasonically dispersed in water;
[0026] After standing, the upper liquid is separated from the precipitate; among them, the alloy nanocluster electrocatalyst is suspended in the upper liquid;
[0027] The upper liquid is centrifuged to obtain the alloy nanocluster electrocatalyst.
[0028] On the other hand, some embodiments disclose an alloy nanocluster electrocatalyst obtained by the preparation method of the alloy nanocluster electrocatalyst.
[0029] The preparation method of the alloy nanocluster electrocatalyst disclosed in the embodiments of the present invention uses silicon carbide or alumina as a templating agent, which has an effective confinement effect on the formed alloy nanoclusters during the alloying process of the cobalt-based alloy nanocluster electrocatalyst precursor, effectively restricting the agglomeration and growth of the alloy nanoclusters, making the alloy nanocluster particles remain at the nanoscale and evenly dispersed, and having good catalytic effects; moreover, the preparation method has a simple process and easy-to-control conditions, and has good application prospects in the industrial preparation of alloy nanocluster electrocatalysts. Description of the Drawings
[0030] Figure 1 、 one The flow chart of the preparation method disclosed in some embodiments;
[0031] Figure 2 、SEM images of the alloy and silicon carbide in Example 2;
[0032] Figure 3 、SEM images of the alloy nanoclusters attached to the surface of silicon carbide in Example 2;
[0033] Figure 4 、SEM images of the alloy nanoclusters in Example 2;
[0034] Figure 5 、EDS mapping images of the alloy nanoclusters in Example 2. Detailed Embodiments
[0035] The special term "embodiment" here, any embodiment described as "exemplary" does not have to be construed as superior to or better than other embodiments. For the performance index tests in the embodiments of the present invention, unless otherwise specified, conventional test methods in the art are used. It should be understood that the terms described in the embodiments of the present invention are only for describing specific embodiments and are not used to limit the content disclosed in the embodiments of the present invention.
[0036] Unless otherwise specified, the technical and scientific terms used herein have the same meanings as commonly understood by those of ordinary skill in the technical field to which the embodiments of the present invention belong; other test methods and technical means not specifically noted in the embodiments of the present invention refer to the experimental methods and technical means commonly used by those of ordinary skill in the art.
[0037] The terms "substantially" and "about" as used herein are used to describe minor fluctuations. For example, they can refer to less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%. Numerical data presented or represented herein in a range format is used only for convenience and brevity and should therefore be interpreted flexibly as including not only the values explicitly listed as the bounds of the range but also all individual values or sub-ranges included within that range. For example, the numerical range of "1 to 5%" should be interpreted as including not only the explicitly listed values of 1% to 5% but also the individual values and sub-ranges within the indicated range. Thus, within this numerical range, individual values such as 2%, 3.5%, and 4% are included, and sub-ranges such as 1% to 3%, 2% to 4%, and 3% to 5% etc. This principle also applies to ranges that list only one numerical value. In addition, such an interpretation applies regardless of the width of the range or the characteristics described.
[0038] In this document, including in the claims, conjunctions such as "comprising", "including", "carrying", "having", "containing", "involving", "accommodating", etc. are understood to be open-ended, that is, meaning "including but not limited to". Only the conjunctions "consisting of" and "composed of" are closed conjunctions.
[0039] For a better illustration of the content of the present invention, numerous specific details are given in the following specific embodiments. Those skilled in the art should understand that the present invention can be implemented without some specific details. In the embodiments, some methods, means, instruments, equipment, etc. well-known to those skilled in the art are not described in detail in order to highlight the gist of the present invention.
[0040] On the premise of no conflict, the technical features disclosed in the embodiments of the present invention can be combined arbitrarily, and the obtained technical solutions belong to the content disclosed in the embodiments of the present invention.
[0041] In some embodiments, as Figure 1 shown, the preparation method of the alloy nanocluster electrocatalyst includes the steps:
[0042] S1. Using an organic ligand, a surface capping agent, and a transition metal cobalt salt to prepare a cobalt-based metal covalent organic framework material precursor; wherein, the surface capping agent is used to limit the particle size growth of the metal covalent organic framework material;
[0043] In some embodiments, the organic ligand is dimethylimidazole and the surface capping agent is cetyltrimethylammonium bromide;
[0044] In some embodiments, the method for preparing the cobalt-based metal covalent organic framework material precursor includes:
[0045] Dissolve the organic ligand in deionized water to obtain an organic ligand solution;
[0046] Add the surface capping agent to the organic ligand solution and stir;
[0047] Add the transition metal salt solution and continue stirring;
[0048] Centrifuge to collect the precipitate, wash it, and thus obtain the cobalt-based metal covalent organic framework material precursor;
[0049] S2. Mix the cobalt-based metal covalent organic framework material precursor with other transition metal salts to obtain a cobalt-based alloy nanocluster electrocatalyst precursor; the other transition metal salts include iron, nickel, manganese, tungsten, molybdenum, vanadium or chromium salts, excluding cobalt salts; the molar ratio of the other transition metal salts to the transition metal cobalt salt is 1:1; generally, when preparing the cobalt-based metal covalent organic framework material precursor, the transition metal cobalt salt is added to form the Co-based metal covalent organic framework material. Further adding one or more other transition metal salts to the cobalt-based metal covalent organic framework material can dope and embed other metal ions into the Co-based metal covalent organic framework material; adding different transition metals step by step is beneficial to better controlling the morphology and yield of the precursor, while adding them together will result in uncontrollable morphology and particle size of the Co-based metal covalent organic framework material and reduce the yield;
[0050] In some embodiments, the method for preparing the cobalt-based alloy nanocluster electrocatalyst precursor includes:
[0051] Disperse the cobalt-based metal covalent organic framework material precursor in deionized water, and add other transition metal salts with an equimolar ratio to the cobalt-based metal covalent organic framework material precursor; stir at room temperature;
[0052] Collect the precipitate, wash it, and dry it to obtain the cobalt-based alloy nanocluster electrocatalyst precursor;
[0053] S3. Mix the cobalt-based alloy nanocluster electrocatalyst precursor with a templating agent to obtain a raw material mixture; the templating agent is micron-scale silicon carbide / aluminum oxide, and the mass ratio of the templating agent to the cobalt-based alloy nanocluster electrocatalyst precursor is 3:1;
[0054] S4. The raw material mixture is alloyed under discharge plasma heating to generate alloy nanocluster electrocatalyst products; usually, the conditions for discharge plasma heating include: vacuum environment, pressure of 10-40Mpa, heating temperature of 800-1200℃, and insulation time of no more than 30min; generally, during the high-temperature treatment of discharge plasma, the precursor powder contains a variety of metal elements and carbon elements, which can provide various metal sources and carbon sources required for forming the alloy; during the high-temperature process, the precursor powder is first thermally decomposed, dehydrogenated and deoxidized, and the carbon element in the precursor reduces the ionic metal to a metal element; at high temperature, the liquid elemental metal fuses to form an alloy, and then rapidly cools, and the alloy nanoclusters solidify on the surface of silicon carbide or aluminum oxide particles; silicon carbide or aluminum oxide particles do not react with other substances and do not react themselves during the high-temperature process, and only act as a template for confined isolation in the process, isolating the precursor powder to prevent it from agglomerating and growing.
[0055] S5, purifying and separating the alloy nanocluster electrocatalyst product, removing the template agent, and obtaining the alloy nanocluster electrocatalyst;
[0056] In some embodiments, the purification and separation method comprises:
[0057] The alloy nanocluster electrocatalyst product was ground and then ultrasonically dispersed in water;
[0058] After standing, the upper layer of liquid is separated from the precipitate; wherein the upper layer of liquid contains alloy nanocluster electrocatalyst suspended therein;
[0059] The upper layer of liquid is centrifuged to obtain the alloy nanocluster electrocatalyst.
[0060] The alloy nanocluster electrocatalyst disclosed in some embodiments is obtained by a preparation method of the alloy nanocluster electrocatalyst.
[0061] The technical details are further illustrated below in conjunction with embodiments.
[0062] Example 1
[0063] Example 1 discloses a method for preparing an alloy nanocluster electrocatalyst comprising:
[0064] Dissolve 10g of organic ligand dimethylimidazole in 150ml of deionized water and add 5ml of 0.01mol·L -1 The surface capping agent hexadecyl trimethyl ammonium bromide solution was stirred at room temperature for 10 minutes, and then 20 ml of 0.17 mol·L -1 The cobalt nitrate solution was stirred for 12 h and the precipitate was collected by centrifugation;
[0065] The precipitate was washed several times with anhydrous methanol and deionized water successively to obtain the cobalt-based metal covalent organic framework material as the precipitate, which was dried at 60 °C in an air atmosphere for later use;
[0066] Weigh 2 g of the dried cobalt-based metal covalent organic framework material, ultrasonically disperse it in deionized water, and then add nickel salt, iron salt, manganese salt, tungsten salt, molybdenum salt, vanadium salt or chromium salt in an equimolar ratio; stir at room temperature for 2 h, collect the precipitate, wash it several times with deionized water, and dry it at 60 °C in an air atmosphere for later use;
[0067] Mix 1 g of the dried powder sample thoroughly with 3 g of silicon carbide particles or alumina particles with a micron particle size to obtain a mixed precursor powder;
[0068] Heat alloy the mixed precursor powder using the spark plasma method. Under a vacuum environment, the pressure is 10 - 40 Mpa, quickly heat up to 800 - 1200 °C, and keep the temperature for 0 - 30 min;
[0069] Thoroughly grind the alloyed mixture powder, ultrasonically disperse it in water with high power for 5 - 90 min, let it stand for 1 - 10 min, separate the upper black liquid from the precipitate, centrifuge to collect the suspended nanoalloy particles in the black liquid, wash it several times with deionized water, and dry it at 60 °C in an air or vacuum atmosphere to obtain the nanoalloy cluster electrocatalyst.
[0070] Example 2
[0071] The preparation method of the alloy nano-cluster electrocatalyst disclosed in Example 2 includes:
[0072] Dissolve 5 g of the organic ligand dimethylimidazole in 80 ml of deionized water, add 2.5 ml of a cetyltrimethylammonium bromide solution with a concentration of 0.01 mol·L -1 as the surface capping agent, stir at room temperature for 10 min, then add 20 ml of a cobalt nitrate hexahydrate solution with a concentration of 0.17 mol·L -1 , and continuously stir for 10 h, then centrifuge to collect the precipitate;
[0073] The precipitate was washed several times with anhydrous methanol and deionized water successively to obtain the cobalt-based metal covalent organic framework material as the precipitate, which was dried at 60 °C in an air atmosphere for later use;
[0074] Weigh 2 g of the dried cobalt-based metal covalent organic framework material, ultrasonically disperse it in deionized water, and then add nickel nitrate in an equimolar ratio, stir at room temperature for 2 h, collect the precipitate, wash it several times with deionized water, and dry it at 60 °C in an air atmosphere for later use;
[0075] Mix 1 g of the dried powder sample thoroughly with 3 g of silicon carbide particles with a micron particle size to obtain a mixed precursor powder;
[0076] The mixed precursor powder is subjected to heating alloying using the spark plasma method. In a vacuum environment with a pressure of 20 Mpa, it is rapidly heated to 1000 °C and held for 10 min.
[0077] The alloyed mixture powder is thoroughly ground, dispersed in water by high-power ultrasound for 60 min, allowed to stand for 1 min, and the upper black liquid is separated from the precipitate. The suspended nano-alloy particles in the black liquid are collected by centrifugation, washed several times with deionized water, and dried at 60 °C in an air or vacuum atmosphere to obtain the nano-alloy cluster electrocatalyst.
[0078] The nano-alloy cluster electrocatalyst obtained in Example 2 is tested, and the results are as Figure 2 、 3 、4, 5.
[0079] In Example 2, CoFeNiMnMo nano-alloy clusters were prepared by adding four metal salts of Fe, Ni, Mn, and Mo in equimolar ratios. From Figures 2 to 4 it can be seen that nano-alloy clusters are uniformly dispersed on the surface of silicon carbide, and the particles are all at the nano scale, and no agglomeration phenomenon is observed. From Figure 5 it can be seen that Co, Fe, Ni, Mn, and Mo all have strong and obvious signals in the alloy nano-clusters, and the signal profiles are basically the same, indicating that the metal elements are evenly distributed in the alloy nano-clusters, forming a good alloy phase.
[0080] The preparation method of the alloy nano-cluster electrocatalyst disclosed in the embodiments of the present invention uses silicon carbide or alumina as a template agent. During the alloying process of the cobalt-based alloy nano-cluster electrocatalyst precursor, it has an effective confinement effect on the formed alloy nano-clusters, effectively restricting the agglomeration and growth of the alloy nano-clusters, enabling the alloy nano-cluster particles to remain at the nano scale and be evenly dispersed, with good catalytic effects; moreover, the preparation method has a simple process and easy-to-control conditions, and has good application prospects in the industrial preparation of alloy nano-cluster electrocatalysts.
[0081] The technical solutions disclosed in the embodiments of the present invention and the technical details disclosed in the examples are only exemplary explanations of the inventive concept of the present invention, and do not constitute a limitation on the technical solutions of the embodiments of the present invention. Any conventional changes, substitutions, or combinations made to the technical details disclosed in the embodiments of the present invention have the same inventive concept as the present invention and are within the protection scope of the claims of the present invention.
Claims
1. A method for preparing an alloy nanocluster electrocatalyst, characterized in that: Includes steps: S1. Preparing a cobalt-based metal covalent organic framework material precursor using an organic ligand, a surface capping agent, and a transition metal cobalt salt; S2, mixing the cobalt-based metal covalent organic framework material precursor with other transition metal salts to obtain a cobalt-based alloy nanocluster electrocatalyst precursor; wherein the other transition metal salts include iron, nickel, manganese, tungsten, molybdenum, vanadium or chromium salts, but not cobalt salts; the molar ratio of the other transition metal salts to the transition metal cobalt salt is 1:1; S3, mixing a cobalt-based alloy nanocluster electrocatalyst precursor with a template to obtain a raw material mixture; the template is micron-sized silicon carbide / aluminum oxide, and the mass ratio of the template to the cobalt-based alloy nanocluster electrocatalyst precursor is 3:1; S4, alloying the raw material mixture under discharge plasma heating to generate an alloy nanocluster electrocatalyst product; S5. Purify and separate the alloy nanocluster electrocatalyst product, remove the template agent, and obtain the alloy nanocluster electrocatalyst.
2. The method for preparing the alloy nanocluster electrocatalyst according to claim 1, characterized in that: The organic ligand is dimethylimidazole.
3. The method for preparing the alloy nanocluster electrocatalyst according to claim 1, characterized in that: The surface capping agent is hexadecyltrimethylammonium bromide.
4. The method for preparing the alloy nanocluster electrocatalyst according to claim 1, characterized in that: In step S1, the method for preparing a cobalt-based metal covalent organic framework material precursor comprises: The organic ligand is dissolved in deionized water to obtain an organic ligand solution; Add the surface capping agent to the organic ligand solution and stir; Add transition metal salt solution and continue stirring; The precipitate is collected by centrifugation and washed to obtain a cobalt-based metal covalent organic framework material precursor.
5. The method for preparing the alloy nanocluster electrocatalyst according to claim 1, characterized in that: In step S2, the method for preparing the cobalt-based alloy nanocluster electrocatalyst precursor comprises: Dispersing a cobalt-based metal covalent organic framework material precursor in deionized water, adding other transition metal salts in an equal molar ratio to the cobalt-based metal covalent organic framework material precursor; stirring at room temperature; The precipitate is collected, washed, and dried to obtain a cobalt-based alloy nanocluster electrocatalyst precursor.
6. The method for preparing the alloy nanocluster electrocatalyst according to claim 1, characterized in that: In step S4, the conditions for discharge plasma heating include: vacuum environment, pressure of 10-40 MPa, heating temperature of 800-1200° C., and insulation time of no more than 30 min.
7. The method for preparing the alloy nanocluster electrocatalyst according to claim 1, characterized in that: In step S5, the purification and separation method includes: The alloy nanocluster electrocatalyst product was ground and then ultrasonically dispersed in water; After standing, the upper layer of liquid is separated from the precipitate; wherein the upper layer of liquid contains alloy nanocluster electrocatalyst suspended therein; The upper layer of liquid is centrifuged to obtain the alloy nanocluster electrocatalyst.
8. Alloy nanocluster electrocatalyst, characterized in that The alloy nanocluster electrocatalyst is obtained by the preparation method of any one of claims 1 to 7.