Iron-cobalt-nickel particle / carbon nano composite material catalyst, preparation method thereof and application of iron-cobalt-nickel particle / carbon nano composite material catalyst in electro-catalysis oxygen evolution reaction

Abstract

The invention discloses an iron-cobalt-nickel particle / carbon nano composite material catalyst, a preparation method thereof and application of the iron-cobalt-nickel particle / carbon nano composite material catalyst in an electro-catalysis oxygen evolution reaction, and belongs to the technical field of electro-catalysis. The preparation method of the catalyst comprises the following steps: (1) adding iron nitrate nonahydrate, cobalt nitrate hexahydrate and nickel acetate tetrahydrate into a polyvinylpyrrolidone solution to prepare a uniformly dispersed solution; (2) drying the dispersion liquid in a drying oven to obtain precursor powder; and (3) carrying out annealing treatment on the precursor to finally obtain the catalyst with a core-shell structure. The iron-cobalt-nickel particle / carbon composite material prepared by the invention has excellent oxygen evolution performance as an efficient oxygen evolution catalyst. The iron-cobalt-nickel particle / carbon nano composite material prepared by the method is used as an efficient oxygen evolution catalyst and has excellent oxygen evolution performance.

Description

Technical Field

[0001] The invention relates to the technical field of electrocatalysis, and in particular to an iron-cobalt-nickel particle / carbon nanocomposite catalyst and a preparation method thereof, and application thereof in an electrocatalytic oxygen evolution reaction. Background Art

[0002] With the rapid development of renewable energy, water electrolysis has attracted much attention as a clean and efficient hydrogen production method. As the anode reaction in the process of water electrolysis, the oxygen evolution reaction has a slow kinetic reaction due to the four-electron transfer process involved, which has become one of the key factors restricting the efficiency and cost of water electrolysis hydrogen production. In addition, the large-scale application of rechargeable metal-air batteries also requires efficient and stable oxygen evolution electrocatalysts to reduce the charging overpotential and improve the battery's cycle performance and energy efficiency. Therefore, the development of high-performance and low-cost oxygen evolution electrocatalysts is of great practical significance. Iron, cobalt, and nickel, as transition metals, have similar electronic structures and chemical properties, and their alloys show unique advantages in the electrocatalytic oxygen evolution reaction. On the one hand, iron-cobalt-nickel particles usually have good conductivity, which can effectively promote the transmission of electrons and reduce the resistance loss during the reaction; on the other hand, by adjusting the ratio of iron, cobalt, and nickel and the preparation process, the crystal structure, electronic structure, and surface properties of the alloy can be regulated, thereby exposing more active sites and improving the catalytic activity for the oxygen evolution reaction. Moreover, compared with traditional precious metal oxygen evolution electrocatalysts, iron-cobalt-nickel particles have abundant reserves and relatively low costs, which makes them have greater economic advantages in large-scale applications.

[0003] Although iron-cobalt-nickel particles have shown many advantages and potentials in electrocatalytic oxygen evolution, they still face some challenges and limitations. First, although some progress has been made in catalytic activity, compared with traditional precious metal catalysts, the ability of iron-cobalt-nickel particles to achieve high current density at low overpotentials is still limited, which may affect the efficiency of hydrogen production by electrolysis of water in practical applications; second, the stability issue is one of the key factors restricting its long-term application. During the long-term oxygen evolution reaction, the alloy is prone to surface oxidation, corrosion or structural reconstruction, which will lead to a gradual decrease in catalytic activity, thereby affecting the cycle stability and service life of the electrode. Third, the structure-activity relationship between the microstructure and catalytic performance of the alloy and the specific mechanism of the oxygen evolution reaction are not yet fully understood, which to a certain extent limits the rational design and optimization of high-performance catalysts. Therefore, in order to further improve the electrocatalytic oxygen evolution performance of iron-cobalt-nickel particles, it is an important development trend to compound the alloy with other materials or construct a heterojunction to achieve a synergistic effect. Summary of the invention

[0004] In order to overcome the deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide an iron-cobalt-nickel particle / carbon nanocomposite catalyst and a preparation method thereof and application in an electrocatalytic oxygen evolution reaction. The preparation method is simple, efficient, reproducible and low-cost. The prepared electrocatalyst improves the conductivity of the material, and there is a synergistic effect between the three metals of iron, cobalt and nickel, which reduces the energy barrier of the catalytic reaction and improves the activity of the oxygen evolution reaction.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is as follows:

[0006] An iron-cobalt-nickel particle / carbon nanocomposite material catalyst is composited from iron-cobalt-nickel particles and a carbon material, wherein the carbon material is graphite.

[0007] Furthermore, the catalyst is a nano-scale powder, wherein the size of the iron-cobalt-nickel particles is 10-50 nm.

[0008] Furthermore, the iron-cobalt-nickel particles are one or more of iron-nickel alloy particles, iron-cobalt-nickel alloy particles and cobalt metal particles, and the contents of iron, cobalt and nickel elements in the electrocatalyst are not zero.

[0009] Furthermore, the method for preparing the iron-cobalt-nickel particle / carbon nanocomposite catalyst comprises the following steps:

[0010] (1) using ferric nitrate nonahydrate, cobalt nitrate hexahydrate, nickel acetate tetrahydrate and polyvinyl pyrrolidone as raw materials, first preparing a polyvinyl pyrrolidone solution, then sequentially adding ferric nitrate nonahydrate, cobalt nitrate hexahydrate and nickel acetate tetrahydrate to the polyvinyl pyrrolidone solution, and stirring to obtain a mixed solution;

[0011] (2) placing the mixed solution obtained in step (1) into an oven for drying, collecting the product, and grinding it to obtain a brown precursor powder;

[0012] (3) The brown precursor powder obtained in step (2) is subjected to high-temperature annealing treatment in a tubular furnace under a nitrogen atmosphere, the high-temperature annealing temperature is 600-800° C., and the annealing time is 1-3 hours. The annealed product is washed and dried to obtain a magnetic black powder, which is the iron-cobalt-nickel particle / carbon nanocomposite catalyst.

[0013] Furthermore, in the raw materials of step (1), the ratio of ferric nitrate nonahydrate, cobalt nitrate hexahydrate, nickel acetate tetrahydrate and polyvinyl pyrrolidone is (0.5-2.0) g: (0.3-0.15) g: (0.2-0.15) g: (10-60) mL; the polyvinyl pyrrolidone solution is obtained by adding polyvinyl pyrrolidone powder to deionized water and stirring in a 60° C. water bath for 1 hour to fully dissolve it, and its concentration is 2-5 vol%.

[0014] Furthermore, in the raw materials of step (1), the preferred weight ratio of ferric nitrate nonahydrate, cobalt nitrate hexahydrate, nickel acetate tetrahydrate and polyvinyl pyrrolidone is 0.6 g: 0.4 g: 0.3 g: (10-60) mL.

[0015] Furthermore, in step (2), the drying temperature is 100° C. and the drying time is 12-24 hours.

[0016] Furthermore, during the annealing treatment in step (3), the heating rate of the tubular furnace is 5°C / min, the cooling rate is 5°C / min, and the temperature is reduced to 300°C and then naturally cooled.

[0017] Furthermore, in step (3), the product (black powder) obtained after annealing is centrifugally washed with deionized water and anhydrous ethanol in sequence, and the centrifuged product is dried in a drying oven at 60° C. for 12 hours to obtain the iron-cobalt-nickel particle / carbon nanocomposite catalyst.

[0018] The iron-cobalt-nickel particle / carbon nanocomposite catalyst is used in the electrolytic production of hydrogen by water or in the electrocatalytic oxygen evolution reaction in a rechargeable metal-air battery.

[0019] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0020] 1. The catalyst prepared by the present invention is an iron-cobalt-nickel particle / carbon nanocomposite powder. The composite material has good electrical conductivity, synergy and catalytic performance. The nanoparticles of iron-cobalt-nickel particles and carbon improve the electrical conductivity of the material, and there is a synergistic effect between the three elements of iron, cobalt and nickel in the iron-cobalt-nickel particles, which reduces the energy barrier of the reaction and improves the activity of the oxygen evolution reaction.

[0021] 2. The present invention synthesizes the iron-cobalt-nickel particle / carbon composite catalyst by directly annealing the precursor powder. The preparation process is simple, repeatable and low-cost, and provides a feasible preparation method for the application of non-precious metal composite materials in oxygen evolution reaction.

[0022] 3. In the iron-cobalt-nickel particle / carbon nanocomposite catalyst provided by the present invention, carbon (graphite) improves the conductivity and stability of the catalyst and improves the activity of the oxygen evolution reaction.

[0023] 4. The iron-cobalt-nickel particle / carbon nanocomposite catalyst provided by the present invention is applied to the electrocatalytic oxygen evolution reaction, which reduces the oxygen evolution overpotential and exhibits excellent electrocatalytic oxygen evolution performance, providing a new idea for the design of the application of electrocatalytic oxygen evolution reaction in water electrolysis to produce hydrogen and rechargeable metal-air batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1The X-ray diffraction pattern of the iron-cobalt-nickel particle / carbon nanocomposite catalyst prepared in Example 1;

[0025] Figure 2 This is a transmission electron microscopy image of the iron-cobalt-nickel particle / carbon nanocomposite catalyst prepared in Example 1;

[0026] Figure 3 The oxygen evolution LSV performance diagram of the iron-cobalt-nickel particle / carbon nanocomposite catalyst prepared in Example 1 and Comparative Examples 1-2;

[0027] Figure 4 This is the IT stability performance diagram of the iron-cobalt-nickel particle / carbon nanocomposite catalyst prepared in Example 1. DETAILED DESCRIPTION

[0028] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0029] Embodiment 1:

[0030] The process of preparing the iron-cobalt-nickel particle / carbon nanocomposite catalyst in this embodiment is as follows:

[0031] 1. Add polyvinyl pyrrolidone powder to deionized water and stir in a 60°C water bath for 1 hour to fully dissolve to obtain a polyvinyl pyrrolidone solution with a concentration of 5 vol%.

[0032] 2. Using 30 ml of polyvinyl pyrrolidone solution as solvent, add 0.6 g of ferric nitrate nonahydrate, 0.4 g of cobalt nitrate hexahydrate, and 0.3 g of nickel acetate tetrahydrate into the polyvinyl pyrrolidone solution in sequence, and stir for 1 hour to obtain a mixed solution.

[0033] 3. Preparation of precursor powder: The obtained mixed solution was placed in an oven at 100° C. and dried for 20 hours. After drying, the product was collected and ground to obtain a brown precursor powder.

[0034] 4. Annealing: The brown precursor powder was subjected to high temperature annealing in a tubular furnace under nitrogen atmosphere. The high temperature annealing was maintained at 700°C for 2 hours. The heating rate in the tubular furnace was 5°C / min. After the annealing was completed, the temperature was lowered to 300°C at a cooling rate of 5°C per minute and then cooled naturally. The obtained product was cleaned by centrifugation with deionized water and anhydrous ethanol in turn, and then dried in an oven at 60°C for 12 hours to obtain a black powder with magnetic properties, which was the iron-cobalt-nickel particle / carbon nanocomposite catalyst.

[0035] Figure 1 From the X-ray diffraction pattern of the catalyst prepared in this example, it can be seen that the synthesized product is consistent with the standard PDF cards of graphite, iron-nickel alloy, and cobalt metal.

[0036] Figure 2 The transmission electron microscope image of the catalyst prepared in this example shows that its morphology is a composite material of iron-cobalt-nickel particles and carbon (graphite). The size of the iron-cobalt-nickel particles (iron-nickel alloy and cobalt metal) is 10-50 nm.

[0037] Comparative Example 1

[0038] The process of preparing the iron-cobalt-nickel particle / carbon nanocomposite catalyst in this example is different from that in Example 1 in that the temperature of the annealing treatment in step 4 is 600° C., and a magnetic black powder is finally obtained.

[0039] Comparative Example 2

[0040] The process of preparing the iron-cobalt-nickel particle / carbon nanocomposite catalyst in this example is different from that in Example 1 in that the temperature of the annealing treatment in step 4 is 800° C., and a magnetic black powder is finally obtained.

[0041] Application performance analysis:

[0042] The main difference between Example 1 and Comparative Examples 1 and 2 is that the sintering temperatures in step 3 are different.

[0043] The catalysts prepared in Example 1 and Comparative Examples 1-2 were prepared into electrode liquids, which were drop-coated on a glassy carbon electrode with a diameter of 3 mm. After drying, the electrochemical performance was tested in an electrochemical workstation using a three-electrode system, and the oxygen evolution overpotentials shown in Table 1 were obtained:

[0044] Table 1 Comparison of oxygen evolution performance of catalysts in Example 1 and Comparative Examples 1-2

[0045] Sintering temperature <![CDATA[Overpotential / 10 mA / cm 2 > Example 1 700℃ 276mV Comparative Example 1 600℃ 391mV Comparative Example 2 800℃ 335mV

[0046] It can be concluded from the data in Table 1 that when the sintering temperature is set to 700°C, the oxygen evolution overpotential is the smallest, which is 115 mV and 59 mV lower than the oxygen evolution overpotential when the sintering temperature is 600°C and 800°C, respectively.

[0047] Figure 3 1 is the oxygen evolution LSV performance diagram of the catalysts prepared at different annealing temperatures in Example 1 and Comparative Examples 1-2. It can be seen that the catalyst material in Example 1 has excellent electrocatalytic oxygen evolution performance.

[0048] Figure 4 This is the IT stability performance diagram of the catalyst prepared in Example 1; it can be seen that the catalyst material in Example 1 has excellent stability.

[0049] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. An iron-cobalt-nickel particle / carbon nanocomposite catalyst, characterized in that: The catalyst is composited by iron-cobalt-nickel particles and carbon material, and the carbon material is graphite.

2. The iron-cobalt-nickel particle / carbon nanocomposite catalyst according to claim 1, characterized in that: The catalyst is a nanometer-scale powder, wherein the size of the iron, cobalt and nickel particles is 10-50nm.

3. The iron-cobalt-nickel particle / carbon nanocomposite catalyst according to claim 1, characterized in that: The iron-cobalt-nickel particles are one or more of iron-nickel alloy particles, iron-cobalt-nickel alloy particles and cobalt metal particles, and the contents of iron, cobalt and nickel elements in the electrocatalyst are not zero.

4. The method for preparing the iron-cobalt-nickel particle / carbon nanocomposite catalyst according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: (1) using ferric nitrate nonahydrate, cobalt nitrate hexahydrate, nickel acetate tetrahydrate and polyvinyl pyrrolidone as raw materials, first preparing a polyvinyl pyrrolidone solution, then sequentially adding ferric nitrate nonahydrate, cobalt nitrate hexahydrate and nickel acetate tetrahydrate into the polyvinyl pyrrolidone solution, and stirring to obtain a mixed solution; (2) The mixed solution obtained in step (1) is placed in an oven for drying, and the product is collected and ground to obtain a brown precursor powder; (3) The precursor powder obtained in step (2) is subjected to high-temperature annealing treatment in a tubular furnace under a nitrogen atmosphere, the high-temperature annealing temperature is 600° C.-800° C., and the annealing time is 1-3 hours. The annealed product is washed and dried to obtain a magnetic black powder, which is the iron-cobalt-nickel particle / carbon nanocomposite catalyst.

5. The method for preparing the iron-cobalt-nickel particle / carbon nanocomposite catalyst according to claim 4, characterized in that: In the raw materials of step (1), the ratio of ferric nitrate nonahydrate, cobalt nitrate hexahydrate, nickel acetate tetrahydrate and polyvinyl pyrrolidone is (0.5-2.0) g: (0.3-0.15) g: (0.2-0.15) g: (10-60) mL; the polyvinyl pyrrolidone solution is obtained by adding polyvinyl pyrrolidone powder to deionized water and stirring in a 60° C. water bath for 1 hour to fully dissolve the powder, and the concentration is 2-5 vol%.

6. The method for preparing the iron-cobalt-nickel particle / carbon nanocomposite catalyst according to claim 4, characterized in that: In step (2), the drying temperature is 100° C. and the drying time is 12-24 hours.

7. The method for preparing the iron-cobalt-nickel particle / carbon nanocomposite catalyst according to claim 4, characterized in that: During the annealing treatment in step (3), the heating rate of the tubular furnace is 5°C / min, the cooling rate is 5°C / min, and the temperature is reduced to 300°C and then naturally cooled.

8. The method for preparing the iron-cobalt-nickel particle / carbon nanocomposite catalyst according to claim 4, characterized in that: In step (3), the product (black powder) obtained after annealing is centrifugally washed with deionized water and anhydrous ethanol in sequence, and the centrifuged product is dried in a drying oven at 60° C. for 12 hours to obtain the iron-cobalt-nickel particle / carbon nanocomposite catalyst.

9. Use of the iron-cobalt-nickel particle / carbon nanocomposite catalyst in electrocatalytic oxygen evolution reaction according to claim 1, characterized in that: The catalyst is used in the electrocatalytic oxygen evolution reaction in water electrolysis or rechargeable metal-air batteries.

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