Preparation method of iridium-based alloy electrolytic water catalyst

Abstract

The present invention discloses a preparation method of an iridium-based alloy electrocatalytic water splitting catalyst, comprising: preparing a first dispersion liquid using a carrier, a reducing agent and a first pH regulator as raw materials; preparing a second dispersion liquid using a noble metal precursor and deionized water as raw materials; preparing a third dispersion liquid using the first dispersion liquid and the second dispersion liquid; preparing an alloy catalyst dispersion solution using the third dispersion liquid; using the alloy catalyst dispersion solution and a second pH regulator to sediment the alloy catalyst dispersion solution to prepare a semi-finished supported IrRu alloy catalyst, and then performing gas-solid phase oxidation heat treatment to obtain the iridium-based alloy electrocatalytic water splitting catalyst. In the present invention, while the carrier is pre-dispersed, the surface pH of the carrier is adjusted to improve the number and uniformity of the surface adsorption sites of the carrier, and a supported catalyst with small and uniform metal particle sizes evenly distributed on the carrier can be obtained. The surface electronic energy band structure of Ir is improved through gas-solid phase oxidation heat treatment, and the electrocatalytic performance of the product for water electrolysis is enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalyst preparation, and particularly relates to a preparation method of an iridium-based alloy electrolyzed water catalyst. Background Art

[0002] In recent years, solid polymer electrolysis of water to produce hydrogen (SPEWE) has received extensive attention from all sectors of society as a green hydrogen production technology with advantages such as fast response speed, compact equipment structure, and low equipment process operation and maintenance costs. How to truly implement proton exchange membrane electrolysis of water to produce hydrogen on an industrial scale requires continuous optimization of core raw materials. For example, improving the production processes of key raw materials such as noble metal catalysts, proton exchange membranes, and porous transport layers to improve product stability and reduce preparation costs.

[0003] As commercial electrocatalysts for the oxygen evolution reaction (OER) at the anode of proton exchange membrane water electrolyzers, Ir and IrOx can not only maintain structural stability under strong acidic and high potential conditions but also exhibit excellent electrocatalytic performance. However, due to the high price and scarcity of Ir, it is urgent to improve the oxygen evolution reaction activity of iridium-based catalysts and develop low-iridium-based catalysts. Ru and RuOx have excellent electrolyzed water catalytic performance but are unstable under strong acidic conditions. The most studied iridium-based alloy catalyst is the Ir-Ru alloy catalyst. Their ionic radii are very close, and they are prone to form mixed oxides. The presence of Ru can change the electronic energy band structure of the Ir active component, optimize the adsorption and desorption energy of intermediate products during the OER reaction process, improve the reaction efficiency, and optimize the structural stability of the product. The preparation processes of Ir-Ru alloy catalysts and alloy oxide catalysts generally use the microwave method and the impregnation-gas phase reduction method. The microwave method requires a microwave reactor to achieve continuous high-power output to achieve homogeneous reduction of noble metal precursors, so as to achieve an ideal metal particle size distribution; due to the limitations of the impregnation-gas phase reduction method itself, the metal particle size distribution is relatively wide and prone to agglomeration on the carrier, affecting the initial OER reaction activity and durability.

[0004] Based on this, developing an iridium-based alloy electrolyzed water catalyst with a simple preparation process, high energy efficiency, controllable process, and easy to scale up, as well as the membrane electrode prepared therefrom, has become the focus of researchers in this field. Summary of the Invention

[0005] In order to solve the technical problems existing in the prior art, the purpose of the present invention is to provide a preparation method of an iridium-based alloy electrolyzed water catalyst.

[0006] To achieve the above object and reach the above technical effects, the technical solution adopted by the present invention is as follows:

[0007] A preparation method of an iridium-based alloy electrolyzed water catalyst, characterized by comprising the following steps:

[0008] S1: Weigh a certain amount of carrier, reducing agent and first pH regulator, adjust the pH of the system to alkaline, and perform medium-speed shearing for a certain time to obtain a first dispersion;

[0009] S2: Weigh a certain amount of precious metal precursor and deionized water, mix them, and use a tip ultrasonic device to perform ultrasonic treatment to obtain a second dispersion;

[0010] S3: Place the first dispersion and the second dispersion into a semi-closed polytetrafluoro reaction kettle in sequence, perform high-speed shearing to obtain a uniform third dispersion containing the carrier, precious metal precursor and reducing agent;

[0011] S4: Place the third dispersion into a single-neck flask, put it into a constant-temperature heating magnetic stirrer heated to 90 °C, and then heat it to 150-180 °C at a heating rate of 1-10 °C / min, keep it warm for 2-12 h, and perform liquid-phase reflux reaction to obtain an alloy catalyst dispersion solution;

[0012] S5: Magnetically stir the alloy catalyst dispersion solution under the condition of being immersed in an ice-water bath. After the solution temperature drops to room temperature, add a second pH regulator as a precipitant, adjust the pH of the system to acidic, precipitate for 1-6 h, wash and filter until the chloride ion content in the filtrate is below 10 ppm, and place the filtered solid powder in a vacuum drying oven for drying to obtain a semi-finished supported IrRu alloy catalyst;

[0013] S6: Place the semi-finished supported IrRu alloy catalyst in a tubular furnace for gas-solid phase oxidation heat treatment, then turn off the heating, purge with an inert gas for more than 30 min, take out the material to obtain the required iridium-based alloy electrolyzed water catalyst.

[0014] Further, in step S1, the medium-speed shearing speed is 10-20 m / s, and the shearing duration is 10-60 min.

[0015] Further, in step S1, the carrier is a carbon carrier, and the carbon carrier is one or a combination of several of commercial carbon nanotubes, graphite carbon, titanium dioxide, titanium carbide, niobium oxide, and antimony-doped tin oxide; the reducing agent is one or a combination of several of ethylene glycol, formaldehyde, formic acid, hydrazine hydrate, and sodium borohydride; the first pH regulator is one or two combinations of sodium hydroxide and ammonium bicarbonate.

[0016] Further, in step S2, the ultrasonic frequency is 12 - 24 kHz, the total power of the equipment is 2000 W, the output power is 20% - 50% of the total power, and the ultrasonic duration is 10 - 30 min.

[0017] Further, in step S2, the noble metal precursor includes an Ir-based noble metal precursor or a Ru-based noble metal precursor.

[0018] Further, the Ir-based noble metal precursor is one or a combination of several of chloroiridic acid, sodium chloroiridate, and potassium chloroiridate, and the Ru-based noble metal precursor is one or a combination of several of ruthenium chloride, potassium hexachlororuthenate, and hexaammine ruthenium(III) chloride.

[0019] Further, the molar mass ratio of Ir in the Ir-based noble metal precursor to the molar mass of Ru in the Ru-based noble metal precursor is (1 - 4):(4 - 1).

[0020] Further, in step S3, the high-speed shearing speed is 20 - 40 m / s, and the shearing duration is 60 - 180 min.

[0021] Further, in step S5, an alloy catalyst dispersion solution and a second pH regulator are used to sediment the alloy catalyst dispersion solution to prepare a supported IrRu alloy catalyst semi-finished product; the second pH regulator is a hydrochloric acid solution with a concentration of 1 - 5 mol / L; the filtration method in step S5 is one or a combination of several of positive pressure filtration, membrane filtration, and centrifugal filtration.

[0022] Further, in step S6, the heat treatment atmosphere is a mixture of air and an inert gas, the heat treatment temperature is 200 - 400 °C, and the treatment duration is 30 - 160 min.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] (1) By adopting a segmented carrier, noble metal precursor dispersion process, and liquid-phase reflux method to co-reduce bimetals, on the one hand, a metal solid solution phase with uniform distribution of two crystal phases in the bulk can be obtained. On the other hand, pre-dispersing the noble metal precursor enables subsequent metal salt molecules to be evenly distributed on the surface of the carrier, and a supported catalyst with uniform and fine metal particle size distribution and uniform position distribution of metal particles on the carrier can be obtained; in addition, while pre-dispersing the carrier in the present invention, the surface pH of the carrier is adjusted, further improving the quantity and uniformity of adsorption sites on the carrier surface;

[0025] (2) The gas-solid phase oxidation heat treatment process is adopted to realize the transformation of the noble metal catalyst from amorphous to highly active rutile phase. It is possible to control the enrichment of IrOx on the surface of IrRuOx thermodynamically, which can simultaneously achieve the improvement of the surface electronic energy band structure of Ir by Ru doping and the protection of the internal IrRuOx of the metal oxide particles by the surface-enriched IrOx from the direct corrosion of subsequent acidic and high-potential working conditions, contributing to the improvement of the electrolytic water catalytic performance of the product.

[0026] (3) The preparation process of the catalyst of the present invention is simple and easy to operate, with low equipment cost and maintenance cost, and is easy to realize industrial mass production. Description of the Drawings

[0027] Figure 1 It is the SEM image of the catalyst product prepared in Example 1 of the present invention;

[0028] Figure 2 It is the TEM image of the catalyst product prepared in Example 1 of the present invention;

[0029] Figure 3 It is the histogram of the particle size distribution of the catalyst product prepared in Example 1 of the present invention. Detailed Embodiments

[0030] The present invention will be elaborated in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0031] The following gives a brief overview of one or more aspects to provide a basic understanding of these aspects. This overview is not an exhaustive survey of all contemplated aspects, and is neither intended to identify key or decisive elements of any or all aspects nor to attempt to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description to follow.

[0032] As Figures 1-3 shown, a preparation method of an iridium-based alloy electrolytic water catalyst includes the following steps:

[0033] S1: Weigh a certain amount of carrier, reducing agent and the first pH regulator, adjust the pH of the system to alkaline, and perform medium-speed shearing for 10 - 60 min to obtain the first dispersion; wherein, the dosage ratio of the carrier, reducing agent and the first pH regulator is a fixed value, and the dosages of the carrier, reducing agent and the first pH regulator can be flexibly selected according to actual needs;

[0034] S2: Weigh a certain amount of noble metal precursor and deionized water, and use a tip ultrasonic device for ultrasonic treatment. The ultrasonic frequency is 12 - 24 kHz, the total power of the device is 2000 W, the output power is 20% - 50% of the total power, and the ultrasonic duration is 10 - 30 min to obtain a second dispersion;

[0035] S3: Place the first dispersion and the second dispersion successively in a semi-closed polytetrafluoroethylene reaction kettle, and perform high-speed shearing for 60 - 180 min at a shearing speed of 20 - 40 m / s to obtain a uniformly dispersed third dispersion containing the carrier, noble metal precursor, and reducing agent;

[0036] S4: Place the third dispersion in a single-neck flask and put it into a constant-temperature heating magnetic stirrer heated to 90 °C. The magnetic stirring speed is 200 - 600 rpm, and then heat it to 150 - 180 °C at a heating rate of 1 - 10 °C / min and keep it warm for 2 - 12 h for liquid-phase reflux reaction to obtain an alloy catalyst dispersion solution. Here, the liquid-phase reflux reaction is a common chemical laboratory unit operation process method, which will not be elaborated here;

[0037] S5: Magnetically stir the alloy catalyst dispersion solution at 100 - 300 rpm under the condition of being immersed in an ice-water bath; after the solution temperature drops to room temperature, add a second pH regulator as a precipitant to adjust the pH of the system to acidic, precipitate for 1 - 6 h, wash and filter until the chloride ion content in the filtrate is below 10 ppm. Place the filtered solid powder in a vacuum drying oven with a vacuum degree of 0.1 - 0.3 bar and a drying duration of 8 - 16 h to obtain a semi-finished supported IrRu alloy catalyst;

[0038] S6: Place the semi-finished supported IrRu alloy catalyst in a tubular furnace. The treatment atmosphere is a mixture of air and inert gas, the heat treatment temperature is 200 - 400 °C, and the treatment duration is 30 - 160 min. Then turn off the heating, purge with inert gas for more than 30 min, take out the material to obtain a finished supported IrRu alloy oxide catalyst, which is the required iridium-based alloy electrolyzed water catalyst.

[0039] In step S1, the carrier is a carbon carrier, and the carbon carrier is a combination of one or more of commercial carbon nanotubes, graphite carbon, titanium dioxide, titanium carbide, niobium oxide, and antimony-doped tin oxide; the reducing agent is a combination of one or more of ethylene glycol, formaldehyde, formic acid, hydrazine hydrate, and sodium borohydride; the first pH regulator is a combination of one or two of sodium hydroxide and ammonium bicarbonate.

[0040] In step S2, the noble metal precursor includes an Ir-based noble metal precursor or a Ru-based noble metal precursor. Among them, the Ir-based noble metal precursor is one or a combination of several of chloroiridic acid, sodium chloroiridate, and potassium chloroiridate, and the Ru-based noble metal precursor is one or a combination of several of ruthenium chloride, potassium hexachlororuthenate, and hexaammine ruthenium(III) chloride. The molar mass ratio of Ir in the Ir-based noble metal precursor to Ru in the Ru-based noble metal precursor is (1-4):(4-1).

[0041] In step S5, the second pH regulator is a hydrochloric acid solution with a concentration of 1-5 mol / L. The filtration method in step S5 is one or a combination of several of positive pressure filtration, membrane filtration, and centrifugal filtration.

[0042] Example 1

[0043] A preparation method of an iridium-based alloy electrolyzed water catalyst includes the following steps:

[0044] S1: Weigh 5 g of carbon nanotubes, 932 g of ethylene glycol, and 9.7 g of sodium hydroxide and place them in a polytetrafluoroethylene reaction kettle in sequence. Adjust the pH of the system to 11, and perform medium-speed shearing at a shearing speed of 15 m / s for 30 min to obtain a first dispersion liquid;

[0045] S2: Weigh 7.14 g of chloroiridic acid, 6.77 g of ruthenium chloride, and 69.55 g of deionized water and place them in a polytetrafluoroethylene reaction kettle in sequence. Use a tip ultrasonic device to ultrasonically process for 15 min, with an ultrasonic frequency of 20 kHz, a total power of the device of 2000 W, and an output power of 50% of the total power to obtain a second dispersion liquid;

[0046] S3: Place the first dispersion liquid and the second dispersion liquid in a semi-closed polytetrafluoroethylene reaction kettle in sequence, and perform high-speed shearing at a speed of 30 m / s for a shearing duration of 90 min to obtain a third dispersion liquid;

[0047] S4: Place the third dispersion liquid in a single-neck flask, put it into a constant temperature heating magnetic stirrer heated to 90 °C, with a magnetic stirring speed of 300 rpm. Then, heat it to 180 °C at a heating rate of 5 °C / min and keep it warm for 8 h for liquid-phase reflux reaction to obtain an alloy catalyst dispersion solution;

[0048] S5: Magnetically stir the alloy catalyst dispersion solution at 150 rpm under the condition of being immersed in an ice-water bath; after the solution temperature drops to room temperature, add HCl with a concentration of 5 mol / L as a precipitant, adjust the pH of the system to 2, and precipitate for 6 h. Then, wash and filter with deionized water until the chloride ion content in the filtrate is below 10 ppm. Place the filtered solid powder in a vacuum drying oven, with a vacuum degree of 0.1 bar and a drying duration of 8 h to obtain a supported IrRu alloy catalyst semi-finished product;

[0049] S6: Place the semi-finished supported IrRu alloy catalyst in a tube furnace. The treatment atmosphere is a mixture of air and inert gas. The heat treatment temperature is 300 °C, and the treatment duration is 80 min. Then turn off the heating, purge with inert gas for more than 30 min, take out the material to obtain the required iridium-based alloy electrolytic water catalyst.

[0050] Examples 2 - 8

[0051] The differences between Examples 2 - 8 and Example 1 lie in the different raw materials and process parameters in the preparation method of the iridium-based alloy electrolytic water catalyst. See Table 1 for details.

[0052] Table 1

[0053]

[0054]

[0055] Comparative Example 1

[0056] S1: Weigh 7.14 g of iridium chloride acid, 6.77 g of ruthenium chloride, and 69.55 g of deionized water and place them in a polytetrafluoroethylene reaction kettle in sequence. Use a tip ultrasonic device for ultrasonic treatment. The ultrasonic frequency is 20 kHz, the output power is 50%, and the ultrasonic duration is 15 min to obtain Dispersion Liquid Ⅰ, which is equivalent to the second dispersion liquid in Example 1.

[0057] S2: Weigh 5 g of carbon nanotubes, 932 g of ethylene glycol, the same amount of sodium hydroxide as in Example 1, and Dispersion Liquid Ⅰ, place them in a polytetrafluoroethylene reaction kettle, and perform high-speed shearing at 25 m / s for 90 min to obtain Dispersion Liquid Ⅱ, which is equivalent to the third dispersion liquid in Example 1.

[0058] S3: Place Dispersion Liquid Ⅱ in a single-neck flask, put it into a constant-temperature heating magnetic stirrer heated to 90 °C, with a magnetic stirring speed of 300 rpm. Then heat it to 180 °C at a heating rate of 5 °C / min and keep it warm for 8 h for liquid-phase reflux reaction to obtain an alloy catalyst dispersion solution.

[0059] S4: Magnetically stir the alloy catalyst dispersion solution at 150 rpm under the condition of being immersed in an ice-water bath. After the solution temperature drops to room temperature, add 5 mol / L HCl as a precipitant to adjust the system pH to 2 and precipitate for 6 h. Then wash and filter with deionized water until the chloride ion content in the filtrate is below 10 ppm. Place the filtered solid powder in a vacuum drying oven with a vacuum degree of 0.1 bar and a drying duration of 8 h to obtain the semi-finished catalyst.

[0060] S5: Place the catalyst semi-finished product in a tube furnace. The treatment atmosphere is a mixture of air and inert gas. The heat treatment temperature is 300 °C, and the treatment duration is 80 min. Then, turn off the heating, purge with inert gas for more than 30 min, take out the material, and obtain the finished catalyst.

[0061] Comparative Example 2

[0062] S1: Weigh 5 g of carbon nanotubes, 932 g of ethylene glycol, and the same amount of sodium hydroxide as in Example 1, and place them in a polytetrafluoroethylene reaction kettle in sequence. Perform medium-speed shearing at a shearing speed of 15 m / s for 30 min, and adjust the pH of the system to 11 to obtain the first dispersion.

[0063] S2: Weigh 7.14 g of iridium chloride hydrate, 6.77 g of ruthenium chloride, 69.55 g of deionized water, and the same amount of the first dispersion as in Example 1, and place them in a polytetrafluoroethylene reaction kettle in sequence. Perform high-speed shearing at 25 m / s for 90 min to obtain the second dispersion.

[0064] S3: Place the second dispersion in a single-neck flask and put it into a constant-temperature heating magnetic stirrer heated to 90 °C. The magnetic stirring speed is 300 rpm. Then, heat it to 180 °C at a heating rate of 5 °C / min and keep it warm for 8 h for liquid-phase reflux reaction to obtain the alloy catalyst dispersion solution.

[0065] S4: Magnetically stir the alloy catalyst dispersion solution at 150 rpm under the condition of being immersed in an ice-water bath; after the solution temperature drops to room temperature, add 5 mol / L HCl as a precipitant to adjust the pH of the system to 2, and precipitate for 6 h. Then, wash and filter with deionized water until the chloride ion content in the filtrate is below 10 ppm. Place the filtered solid powder in a vacuum drying oven at a vacuum degree of 0.1 bar for 8 h to obtain the catalyst semi-finished product.

[0066] S5: Place the catalyst semi-finished product in a tube furnace. The treatment atmosphere is a mixture of air and inert gas. The heat treatment temperature is 300 °C, and the treatment duration is 80 min. Then, turn off the heating, purge with inert gas for more than 30 min, take out the material, and obtain the finished catalyst.

[0067] Comparative Example 3

[0068] S1: Weigh 5 g of carbon nanotubes, 932 g of ethylene glycol, the same amount of sodium hydroxide as in Example 1, 7.14 g of iridium chloride hydrate, 6.77 g of ruthenium chloride, and 69.55 g of deionized water, and place them in a polytetrafluoroethylene reaction kettle in sequence. Perform high-speed shearing at 25 m / s for 90 min to obtain the dispersion to be reduced.

[0069] S2: Place the mixed slurry to be reduced in a single-neck flask and put it into a thermostatic heating magnetic stirrer heated to 90 °C with a magnetic stirring speed of 300 rpm. Then, heat it to 180 °C at a heating rate of 5 °C / min and keep it warm for 8 h for liquid-phase reflux reaction to obtain an alloy catalyst dispersion solution;

[0070] S3: Magnetically stir the alloy catalyst dispersion solution at 150 rpm under the condition of being immersed in an ice-water bath; after the solution temperature drops to room temperature, add HCl with a concentration of 5 mol / L as a precipitant to adjust the pH of the system to 2 and precipitate for 6 h. Then, wash and filter with deionized water until the chloride ion content in the filtrate is below 10 ppm. Place the filtered solid powder in a vacuum drying oven with a vacuum degree of 0.1 bar and a drying time of 8 h to obtain a catalyst semi-finished product;

[0071] S4: Place the IrRu alloy catalyst semi-finished product in a tubular furnace. The treatment atmosphere is a mixture of air and inert gas, the heat treatment temperature is 300 °C, and the treatment time is 80 min. Then, turn off the heating, purge with inert gas for more than 30 min, take out the material to obtain a finished catalyst.

[0072] Overpotential test:

[0073] Linear sweep voltammetry (LSV) test, the scanning range is 1.2 - 1.6 V vs RHE (0.544 - 0.944 V vs Hg2SO4), the scanning rate is 10 mV / s, the rotation speed of the rotating disk electrode is 1600 rpm, and compare the potential at 0.00196 A, that is, 10 mA / cm 2 .

[0074] The summary of the alloy oxide particle size and overpotential data of the iridium-based alloy electrolytic water catalysts prepared in Examples 1 - 8 is shown in Table 2.

[0075] Table 2

[0076]

[0077] The summary of the alloy oxide particle size and overpotential data of the catalysts prepared in Comparative Examples 1 - 3 is shown in Table 3.

[0078] Table 3

[0079]

[0080] Figure 1 Figure 5000X enlarged view of the scanning electron microscope of the iridium-based alloy electrolytic water catalyst of Example 1. It can be seen that the noble metal particles are evenly distributed on the surface of the porous support, and there are no visible micron-sized metal agglomerate aggregates to the naked eye; Figure 2Transmission electron microscope magnification image of the iridium-based alloy electrolyzed water catalyst of Example 1 Figure 3 Bar graph of the particle size distribution of the catalyst product prepared in Example 1. It can be seen that the metal particles at the nanoscale are small in particle size and evenly distributed, and are also evenly distributed on the surface of the carrier.

[0081] Figures 1-2 From the catalyst morphology and structure, it is verified that the iridium-based alloy electrolyzed water catalyst prepared by the preparation process of the iridium-based alloy electrolyzed water catalyst of the present invention has a uniform particle size distribution and excellent water electrolysis performance.

[0082] According to Table 1-2, the overpotential of the iridium-based alloy electrolyzed water catalyst of Example 1 is 278 mV at a current density of 10 mA / cm 2 The carrier type, reducing agent type, first pH regulator type, and reduction process all affect the performance of the water electrolysis catalyst. Among them, the shear rate of the third dispersion liquid and the reflux reaction temperature have the greatest influence on the overpotential. Comparing Example 5 with Example 1, on the premise that other conditions remain unchanged, when the shear rate of the third dispersion liquid decreases from 30 m / s to 20 m / s, due to the uneven dispersion of the carbon carrier and the precious metal precursor and the insufficient liquid-solid mixing, after the reduction of the precious metal precursor, the overall particle size of the metal particles is larger and the particle size distribution is wider. Comparing Example 7 with Example 1, on the premise that other conditions remain unchanged, when the reflux reaction temperature decreases from 180 °C to 150 °C, the initial nucleation particles during the reduction process of the precious metal become fewer. During the same reduction time, the overall particle size of the metal particles is larger and the particle size distribution is wider.

[0083] As can be seen from Table 3, the pre-dispersion of the carrier has a significant impact on the water electrolysis catalytic performance of the prepared iridium-based alloy electrolyzed water catalyst. If the carrier is not pre-dispersed, such as in Comparative Example 1 and Comparative Example 3, when the precious metal precursor is mixed with the carrier, whether under the conditions of low-speed ball milling or high-speed ball milling dispersion process, compared with Example 1, the overpotential increases by 54 mV and 62 mV respectively at a current density of 10 mA / cm2, and the water electrolysis performance is greatly reduced. Comparing Comparative Example 2 with Example 1, pre-dispersing the carrier helps to improve the water electrolysis performance of the catalyst.

[0084] For parts or structures not specifically described in the present invention, existing technologies or existing products can be used, and no further elaboration will be made here.

[0085] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made using the content of the specification of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A preparation method of an iridium-based alloy electrolytic water catalyst, characterized in that, It includes the following steps: S1: Weigh a certain amount of carrier, reducing agent and the first pH regulator, adjust the pH of the system to alkaline, and perform medium-speed shearing for a certain time to obtain the first dispersion; S2: Weigh a certain amount of noble metal precursor and deionized water, mix them, and use a tip ultrasonic device to perform ultrasonic treatment to obtain the second dispersion; S3: Place the first dispersion and the second dispersion into a semi-closed polytetrafluoroethylene reaction kettle in sequence, perform high-speed shearing to obtain a uniformly dispersed third dispersion containing the carrier, noble metal precursor, and reducing agent; S4: Place the third dispersion into a single-neck flask, put it into a constant-temperature magnetic stirrer with a heating temperature of 90 °C, and then heat it to 150 - 180 °C at a heating rate of 1 - 10 °C / min, keep it warm for 2 - 12 h, and perform liquid-phase reflux reaction to obtain an alloy catalyst dispersion solution; S5: Magnetically stir the alloy catalyst dispersion solution under the condition of being immersed in an ice-water bath. After the solution temperature drops to room temperature, add the second pH regulator as a precipitant, adjust the pH of the system to acidic, precipitate for 1 - 6 h, wash and filter until the chloride ion content in the filtrate is below 10 ppm, place the filtered solid powder into a vacuum drying oven for drying to obtain a semi-finished supported IrRu alloy catalyst; S6: Place the semi-finished supported IrRu alloy catalyst into a tube furnace for gas-solid phase oxidation heat treatment, then turn off the heating, use an inert gas to purge for more than 30 min, take out the material to obtain the required iridium-based alloy electrolytic water catalyst.

2. The preparation method of an iridium-based alloy electrolyzed water catalyst according to claim 1, characterized in that, In step S1, the medium-speed shearing speed is 10 - 20 m / s, and the shearing duration is 10 - 60 min.

3. The preparation method of an iridium-based alloy electrolytic water catalyst according to claim 1, characterized in that, In step S1, the carrier is a carbon carrier, and the carbon carrier is commercial carbon nanotubes and graphite carbon; the reducing agent is one or a combination of ethylene glycol, formaldehyde, formic acid, hydrazine hydrate, and sodium borohydride; the first pH regulator is one or a combination of sodium hydroxide and ammonium bicarbonate.

4. The preparation method of an iridium-based alloy electrolytic water catalyst according to claim 1, wherein, In step S2, the ultrasonic frequency is 12 - 24 kHz, the output power is 20% - 50% of the total power, and the ultrasonic duration is 10 - 30 min.

5. The preparation method of an iridium-based alloy electrolytic water catalyst according to claim 1, wherein, In step S2, the noble metal precursor includes an Ir-based noble metal precursor and a Ru-based noble metal precursor.

6. The preparation method of an iridium-based alloy electrolyzed water catalyst according to claim 5, characterized in that, The Ir-based noble metal precursor is one or a combination of iridium chloride, sodium iridium chloride, and potassium iridium chloride, and the Ru-based noble metal precursor is one or a combination of ruthenium chloride, potassium hexachlororuthenate, and hexammine ruthenium(III) chloride.

7. The preparation method of an iridium-based alloy electrolytic water catalyst according to claim 5, characterized in that, The molar mass ratio of Ir in the Ir-based noble metal precursor to Ru in the Ru-based noble metal precursor is (1 - 4):(4 - 1).

8. The preparation method of an iridium-based alloy electrolytic water catalyst according to claim 1, characterized in that, In step S3, the high-speed shearing speed is 20 - 40 m / s, and the shearing duration is 60 - 180 min.

9. The preparation method of an iridium-based alloy electrolyzed water catalyst according to claim 1, wherein, In step S5, the second pH regulator is a hydrochloric acid solution with a concentration of 1 - 5 mol / L; the filtration method in step S5 is one or a combination of positive pressure filtration, membrane filtration, and centrifugal filtration.

10. The preparation method of an iridium-based alloy electrolytic water catalyst according to claim 1, characterized in that, In step S6, the heat treatment atmosphere is a mixture of air and inert gas, the heat treatment temperature is 200 - 400 °C, and the treatment duration is 30 - 160 min.

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