Iron-cobalt-nickel particle / carbon composite material catalyst for electrocatalytic oxygen evolution reaction as well as preparation method and application of iron-cobalt-nickel particle / carbon composite material catalyst

Abstract

The invention provides an iron-cobalt-nickel particle / carbon composite material catalyst for electro-catalysis oxygen evolution reaction as well as a preparation method and application thereof, and belongs to the technical field of electro-catalysis. The preparation method of the catalyst comprises the following steps: (1) adding sodium citrate dehydrate, cobalt nitrate hexahydrate, nickel nitrate hexahydrate and potassium ferrocyanide trihydrate into a deionized water solvent to prepare a suspension; (2) pouring the supernatant of the suspension, washing the precipitate, and drying in a drying oven to obtain a precursor; and (3) annealing the precursor to obtain the catalyst. The iron-cobalt-nickel particle / carbon composite material prepared by the invention has excellent oxygen evolution performance as an efficient oxygen evolution catalyst.

Description

Technical Field

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

[0002] In the context of the booming development of renewable energy today, hydrogen production by electrolyzing water has attracted wide attention due to its clean and efficient characteristics. Among them, the oxygen evolution reaction, as the key reaction occurring at the anode during electrolysis of water, involves a complex four-electron transfer process, and the reaction kinetics is relatively slow, thus becoming a bottleneck hindering the development of hydrogen production by electrolyzing water towards higher efficiency and lower cost. At the same time, as rechargeable metal-air batteries gradually move towards large-scale application, the demand for efficient and stable oxygen evolution electrocatalysts is becoming increasingly urgent. High-quality catalysts can significantly reduce the charging overpotential and improve the cycle performance and energy conversion efficiency of the battery. Therefore, developing oxygen evolution electrocatalysts with both high performance and low cost has become an important task with great practical value at present.

[0003] These transition metals such as iron, cobalt, and nickel have emerged and shown unique advantages in the field of electrocatalytic oxygen evolution reaction due to their similar electronic structures and chemical properties. In terms of electrical conductivity, iron-cobalt-nickel alloys generally have good electrical conductivity, just like building a high-speed channel for electrons, enabling electrons to be quickly transmitted during the reaction and greatly reducing the energy loss caused by resistance. At the level of activity regulation, by carefully adjusting the proportions of iron, cobalt, and nickel and using different preparation processes, the crystal structure, electronic structure, and surface characteristics of the alloy can be precisely controlled, exposing more catalytically active sites and greatly enhancing the catalytic effect on the oxygen evolution reaction. Moreover, compared with traditional oxygen evolution electrocatalysts mainly composed of noble metals, iron-cobalt-nickel alloys have the significant advantages of rich reserves and low cost, which undoubtedly lays a solid economic foundation for their large-scale popularization and application.

[0004] However, on the path of the development of iron-cobalt-nickel alloys in electrocatalytic oxygen evolution, although the prospects are bright, there are also many thorns and challenges. On the one hand, even though achievements have been made in improving catalytic activity, compared with the well-tested traditional noble metal catalysts, iron-cobalt-nickel alloys still struggle to achieve a high current density at a low overpotential, and this shortcoming is likely to slow down the overall efficiency improvement in the actual scenario of electrolytic water hydrogen production. On the other hand, the stability problem always restricts its long-term development. During the continuous oxygen evolution reaction process, adverse phenomena such as oxidation, corrosion, or structural reconstruction are likely to occur on the alloy surface, leading to a gradual decline in catalytic activity and ultimately seriously affecting the cycle stability and service life of the electrode. In addition, the current scientific community does not fully understand the relationship between the microstructure of the alloy and catalytic performance and the detailed mechanism of the oxygen evolution reaction, and this knowledge gap also hinders the scientific design and optimization of high-performance catalysts to a certain extent. Summary of the Invention

[0005] 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 composite material catalyst for electrocatalytic oxygen evolution reaction, its preparation method and application. The preparation method is simple, efficient, has good repeatability, and low cost. The prepared electrocatalyst improves the conductivity of the material, and there is a synergistic effect among the three metals of iron, cobalt, and nickel, reducing the energy barrier of the catalytic reaction and improving the oxygen evolution reaction activity.

[0006] To achieve the above-mentioned invention purpose, the technical solution adopted by the present invention is as follows:

[0007] A preparation method of an iron-cobalt-nickel particle / carbon composite material catalyst for electrocatalytic oxygen evolution reaction, comprising the following steps:

[0008] (1) Dissolve sodium citrate dihydrate, cobalt nitrate hexahydrate, and nickel nitrate hexahydrate in deionized water in sequence to obtain solution A; dissolve potassium ferricyanide trihydrate in deionized water to obtain solution B. Mix solution A and solution B and stir and react at room temperature for 0.5 - 3 hours to form a suspension, and age for 10 - 15 hours to obtain a precipitate;

[0009] (2) Wash the precipitate obtained in step (1), put it into an oven for drying treatment, then collect the dried product and grind it to obtain a light blue precursor powder;

[0010] (3) Under a nitrogen atmosphere, perform high-temperature annealing treatment on the precursor powder obtained in step (2) through a tubular furnace. The high-temperature annealing temperature is 950 - 1050 °C, and the annealing time is 1 - 3 hours. After the annealing treatment, the product is washed and dried to obtain a magnetic black powder, which is the iron-cobalt-nickel particle / carbon nanocomposite material catalyst.

[0011] Further, in step (1), the weight ratio of sodium citrate dihydrate, cobalt nitrate hexahydrate, nickel nitrate hexahydrate, and potassium ferrocyanide trihydrate is (5 - 12):(0.2 - 1.0):(0.2 - 1.0):(1.0 - 3.0).

[0012] Further, the precipitate in step (1) is obtained by suspending the precipitate for 12 hours and then pouring off the supernatant.

[0013] Further, in step (2), the drying temperature is 50 - 80 °C and the drying time is 8 - 12 hours.

[0014] Further, during the annealing treatment in step (3), the heating rate of the tubular furnace is 3 - 6 °C / min, the cooling rate is 3 - 6 °C / min, and after cooling to 300 °C, it is naturally cooled.

[0015] Further, in step (3), the product (black powder) obtained after annealing is successively centrifugally washed with deionized water and absolute ethanol, and the centrifuged product is dried in an oven at 50 - 80 °C for 8 - 15 hours to obtain the iron cobalt nickel particle / carbon nanocomposite catalyst.

[0016] The prepared catalyst is a powder with a particle size of 0.5 - 2 microns composed of iron cobalt nickel particles and a carbon material, and the carbon material is graphite.

[0017] 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 catalyst are all non - zero.

[0018] The iron cobalt nickel particle / carbon composite catalyst is applied to the electrocatalytic oxygen evolution reaction in electrolytic water for hydrogen production or rechargeable metal - air batteries.

[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 composite material. This composite material with such a structure has good conductivity, synergy, and catalytic performance. The composite particles of iron cobalt nickel particles and carbon improve the conductivity of the material, and there is a synergistic effect among the three elements of iron, cobalt, and nickel in the iron cobalt nickel particles, reducing the energy barrier of the reaction and improving the oxygen evolution reaction activity.

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

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

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

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

[0025] Figure 2 Transmission electron microscopy image of the iron-cobalt-nickel particle / carbon composite catalyst prepared in Example 1;

[0026] Figure 3 Oxygen evolution LSV performance graph of the iron-cobalt-nickel particle / carbon composite catalysts prepared in Example 1 and Comparative Examples 1-2;

[0027] Figure 4 i-t stability performance graph of the iron-cobalt-nickel particle / carbon composite catalyst prepared in Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

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

[0029] Example 1:

[0030] 1. Using 5 grams of sodium citrate dihydrate, 0.6 grams of cobalt nitrate hexahydrate, 0.5 grams of nickel nitrate hexahydrate, and 2 grams of potassium ferrocyanide trihydrate as raw materials, and 500 milliliters of deionized water as the solvent; sodium citrate dihydrate, cobalt nitrate hexahydrate, and nickel nitrate hexahydrate were successively dissolved in 200 milliliters of deionized water to obtain solution A; potassium ferrocyanide trihydrate was dispersed in 300 milliliters of deionized water to obtain solution B; solution A and solution B were mixed and stirred at room temperature for 1 hour to obtain a suspension, and after aging for 12 hours, the supernatant was poured off to obtain a precipitate.

[0031] 2. The obtained precipitate was washed with deionized water and then placed in an oven at 60 °C for drying for 10 hours. The dried product was collected and ground to obtain a light blue precursor powder.

[0032] 3. Annealing treatment: The precursor powder is subjected to high-temperature annealing treatment in a tube furnace under a nitrogen atmosphere. The high-temperature annealing is carried out at 1000 °C for 2 hours, and the heating rate in the tube furnace is 5 °C / min. After the annealing is completed, it is cooled to 300 °C at a cooling rate of 5 °C per minute and then naturally cooled. The obtained product is successively centrifugally washed clean with deionized water and absolute ethanol, and then placed in an oven at 60 °C for drying for 12 hours to obtain a magnetic product, a black powder, which is the iron-cobalt-nickel particle / carbon nanocomposite catalyst.

[0033] Figure 1 The X-ray diffraction pattern of the catalyst prepared in this example is shown. It can be seen that the synthesized product conforms to the standard PDF cards of graphite, iron-nickel alloy, and cobalt metal.

[0034] Figure 2 The transmission electron microscope image of the catalyst prepared in this example is shown. It is a composite material of iron-cobalt-nickel particles and carbon (graphite), and the particle size of the composite material is about 1 μm.

[0035] Comparative Example 1

[0036] The difference between the process of preparing the iron-cobalt-nickel particle / carbon nanocomposite catalyst in this example and that in Example 1 is that: the annealing temperature in Step 3 is 900 °C, and finally a magnetic product, a black powder, is obtained.

[0037] Comparative Example 2

[0038] The difference between the process of preparing the iron-cobalt-nickel particle / carbon nanocomposite catalyst in this example and that in Example 1 is that: the annealing temperature in Step 3 is 1100 °C, and finally a magnetic product, a black powder, is obtained.

[0039] Analysis of application performance:

[0040] The main difference between Example 1 and Comparative Examples 1 and 2 is that: the sintering temperature in Step 3 is different.

[0041] The catalysts prepared in Example 1 and Comparative Examples 1-2 are made into electrode solutions, dropped on a glassy carbon electrode with a diameter of 3 mm, dried, and the electrochemical performance is tested in an electrochemical workstation using a three-electrode system to obtain the oxygen evolution overpotential as shown in Table 1:

[0042] Performance comparison table of Example 1, 2, and 3

[0043] Sintering temperature <![CDATA[Overpotential @ 10 mA / cm 2 > Example 1 1000℃ 288mV Example 2 900℃ 311mV Example 3 1100℃ 318mV

[0044] It can be concluded from the data in Table 1 that: when the sintering temperature of the present invention is set at 1000 °C, the oxygen evolution overpotential is the smallest, which is 23 mV and 40 mV lower than the oxygen evolution overpotentials at the sintering temperatures of 900 °C and 1100 °C, respectively.

[0045] Figure 3 It is the oxygen evolution LSV performance graph of the catalysts prepared in Example 1 and Comparative Examples 1-2 at different annealing temperatures. It can be seen that the catalyst material of Example 1 has excellent electrocatalytic oxygen evolution performance.

[0046] Figure 4 It is the i-t stability performance graph of the catalyst prepared in Example 1; it can be seen that the catalyst material of Example 1 has excellent stability.

[0047] The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing an iron-cobalt-nickel particle / carbon composite material catalyst for electrocatalytic oxygen evolution reaction, characterized in that: The method comprises the following steps: (1) dissolving sodium citrate dihydrate, cobalt nitrate hexahydrate and nickel nitrate hexahydrate in deionized water in sequence to obtain solution A; dissolving potassium ferrocyanide trihydrate in deionized water to obtain solution B; mixing solution A and solution B and stirring at room temperature for 0.5-3 hours to obtain a suspension, and aging for 10-15 hours to obtain a precipitate; (2) washing the precipitate obtained in step (1) and placing it in an oven for drying, then collecting the dried product and grinding it to obtain a light blue 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 950-1050° 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 composite material catalyst.

2. The method for preparing the iron-cobalt-nickel particle / carbon composite material catalyst for electrocatalytic oxygen evolution reaction according to claim 1, characterized in that: In step (1), the weight ratio of the sodium citrate dihydrate, cobalt nitrate hexahydrate, nickel nitrate hexahydrate and potassium ferrocyanide trihydrate is (5-12):(0.2-1.0):(0.2-1.0):(1.0-3.0).

3. The method for preparing the iron-cobalt-nickel particle / carbon composite material catalyst for electrocatalytic oxygen evolution reaction according to claim 1, characterized in that: In step (2), the drying temperature is 50-80° C. and the drying time is 8-12 hours.

4. The method for preparing the iron-cobalt-nickel particle / carbon composite material catalyst for electrocatalytic oxygen evolution reaction according to claim 1, characterized in that: During the annealing treatment in step (3), the heating rate of the tubular furnace is 3-6°C / min, the cooling rate is 3-6°C / min, and the temperature is reduced to 300°C and then naturally cooled.

5. The method for preparing the iron-cobalt-nickel particle / carbon composite material catalyst for electrocatalytic oxygen evolution reaction according to claim 1, 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 centrifugal product is dried in a drying oven at 50-80° C. for 8-15 hours to obtain the iron-cobalt-nickel particle / carbon composite material catalyst.

6. An iron-cobalt-nickel particle / carbon composite catalyst for electrocatalytic oxygen evolution reaction prepared by the method according to any one of claims 1 to 5, characterized in that: The catalyst is composited by iron, cobalt, nickel particles and carbon material, and the carbon material is graphite.

7. The iron-cobalt-nickel particle / carbon composite material catalyst for electrocatalytic oxygen evolution reaction according to claim 6, characterized in that: The catalyst is a powder with a particle size of 0.5-2 microns.

8. The iron-cobalt-nickel particle / carbon composite material catalyst for electrocatalytic oxygen evolution reaction according to claim 6, 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 catalyst are not zero.

9. The use of the iron-cobalt-nickel particle / carbon composite material catalyst for electrocatalytic oxygen evolution reaction according to claim 6, 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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