Preparation method and application of mass-producible ir-based supported water electrolysis catalyst

Abstract

The application is a preparation method and application of an Ir-based load type water electrolysis catalyst which can be mass-produced. The method introduces pressure-assisted regulation. After mixing the organic Ir salt precursor and the carrier, the agglomeration and growth of nanoparticles in the high-temperature annealing process are limited by the pressure environment, and the small-size nanoparticles are uniformly loaded on the surface of the carrier, the interaction between the nanoparticles and the carrier is strengthened, the electronic structure of Ir is adjusted, and the anode catalyst has excellent performance in the electrolytic cell. The application avoids the formation of by-products caused by the use of organic solvents, avoids disordered additional purification steps, and can be easily synthesized at the gram scale.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, and relates to a method for preparing and applying a mass-producible Ir-based supported water electrolysis catalyst. Background Technology

[0002] With the rapid development of the global economy, the consumption of fossil fuels such as coal, oil, and natural gas, which are the main energy sources, has increased dramatically. People are increasingly turning their attention to new clean energy sources such as solar, wind, and hydrogen energy. Among them, clean energy represented by hydrogen energy has attracted increasing attention due to its advantages such as high calorific value, high energy density, and low pollution. Currently, one of the main ways to obtain hydrogen energy is through water electrolysis. By using H2 as an energy carrier, the electrical energy generated from renewable energy sources is stored in the chemical bonds of H2 through the electrochemical cracking of water.

[0003] Proton exchange membrane electrolysis (PEMWE) is a key technology for producing green hydrogen from renewable energy sources. Its anode-side oxygen evolution reaction (OER) requires a high-performance catalyst to accelerate the water electrolysis process. Ir-based materials are the preferred anode catalysts for PEMWE due to their high stability and activity under acidic conditions. However, the scarcity and high cost of Ir hinder the widespread application of PEMWE. Therefore, designing supported catalysts to reduce Ir usage while improving its utilization efficiency and performance is of great significance for promoting the large-scale application of PEMWE.

[0004] Currently, most supported catalysts are prepared by solvothermal methods such as polyol reduction. For example, patent CN116516406 A prepared a Ti4O7 supported IrO catalyst using the polyol method. x While this method can be used to prepare oxygen evolution reaction catalysts, it requires specific solvents and additives for different materials, and some organic solvents may be toxic or environmentally harmful. Furthermore, maintaining nanoparticle uniformity and preventing agglomeration during heat treatment is challenging, leading to reduced utilization efficiency of active sites. Additionally, supported catalysts prepared via the polyol method may experience nanoparticle detachment and growth during the reaction, indicating weak interactions between the support and nanoparticles, which require further enhancement. Therefore, designing a simple and efficient method to prepare supported catalysts with controllable nanoparticle size and strong nano-support interactions remains a pressing problem. Summary of the Invention

[0005] The present application aims at the deficiencies of the existing preparation method of Ir-based supported water electrolysis catalyst, and provides a preparation method and application of mass-produced Ir-based supported water electrolysis anode catalyst.

[0006] The technical scheme of the present application is:

[0007] A preparation method of mass-produced Ir-based supported water electrolysis catalyst, which comprises the following steps:

[0008] (1) adding an organic Ir salt precursor and a carrier into a mixed solvent, stirring for 20-40 minutes under ultrasonic, drying and grinding to obtain a mixed powder;

[0009] The mixed solvent is composed of anhydrous ethanol / deionized water; 0.01-0.1 mmol of the organic Ir salt precursor is added into 10 ml of the mixed solvent; the mass ratio of the organic Ir salt precursor to the carrier is 1:1.6-25:1;

[0010] (2) moving the mixed powder obtained in the above step into a high-pressure furnace, heating to 500-1000 DEG C, annealing under an inert atmosphere for 0.5-48 h, and then cooling to room temperature to obtain the Ir-based supported water electrolysis catalyst with different loadings;

[0011] The pressure of the inert atmosphere is 0.1-50 MPa higher than the standard atmospheric pressure; with the increase of the pressure of the inert gas, the particle size of the Ir nanoparticles shows a downward trend.

[0012] The organic Ir salt precursor is acetylacetone salt.

[0013] The carrier material is one of nano-Ti powder, indium tin oxide (ITO) and antimony-doped tin oxide graphite (ATO); preferably, the carrier material is nano-Ti powder; the size of the carrier material is 10-200 nm.

[0014] The volume ratio of the mixed solvent anhydrous ethanol / deionized water is 1:2-2:1, preferably 1:1.

[0015] The method for drying the mixed solution in step (1) is a rotary evaporation solvent drying method or a blast oven drying method, and after drying, the solid powder is ground for 5-10 minutes.

[0016] The annealing temperature in the heat treatment in step (2) is preferably 600-800 DEG C, the pressure of the inert atmosphere in the heat treatment is preferably 0.1-10 MPa higher than the standard atmospheric pressure or the standard atmospheric pressure in a closed space, the inert gas is argon or nitrogen, the heating rate is 1-50 DEG C / min, and the annealing time is preferably 1-24 hours.

[0017] The catalyst comprises a carrier and small-size Ir nanoparticles loaded on the carrier, the loading amount of the Ir-based nanoparticles is 20-90 wt%, the average particle size of the small-size nanoparticles is 1-10 nm, and the particle size of the Ir nanoparticles decreases with the increase of the pressure of the inert gas.

[0018] The yield of the catalyst reaches the gram level.

[0019] The Ir-based supported water electrolysis catalyst prepared by the method is applied to an electrolytic cell as an anode catalyst.

[0020] The application can be used in a proton exchange membrane electrolytic cell, and due to the advantage of scalable production, the application can be used to solve the problems of complex process, catalyst cost and activity and durability in the application process in the actual production process of the supported catalyst.

[0021] The substantial features of the application are:

[0022] The Ir-based supported water electrolysis catalyst provided by the application has small Ir nanoparticle size and is uniformly distributed on the carrier. The preparation method of the catalyst mainly comprises the following steps: mixing an organic Ir salt precursor with a carrier, performing thermal decomposition reduction to preliminarily obtain Ir clusters loaded on the carrier, and then performing high-temperature calcination treatment on the clusters in an inert atmosphere under the action of pressure for a period of time, so that the preparation of the Ir-based supported catalyst with small size and uniform distribution is realized. The preparation method has simple process and good universality, can easily realize large-scale production of the Ir-based supported catalyst, and due to the presence of pressure, the sintering and growth of the Ir nanoparticles in the heat treatment process can be effectively inhibited, the interaction between the nanoparticles and the carrier is strengthened, and the nanoparticles with a size of less than 10 nm can be loaded on the carrier, which has important scientific and engineering significance in improving the stability of the catalyst.

[0023] The application has the following beneficial effects:

[0024] (1) Based on the traditional high-temperature annealing, the invention innovatively introduces pressure-assisted regulation. Through high-temperature annealing, the Ir salt precursor is fully thermally decomposed and reduced to form Ir clusters. Under the action of pressure, the size of the nanoparticles is restricted, inhibiting the migration and growth of the nanoparticles, so that the small-sized nanoparticles are more uniformly loaded on the support. In the existing synthesis methods, some auxiliary drugs or template materials are usually added, and by-products need to be removed through subsequent purification steps to achieve similar effects. Secondly, the small-sized nanoparticles synthesized by applying appropriate pressure and temperature have a strong interaction with the support, which can effectively regulate the electronic structure of Ir, improve the utilization rate of active sites, and thus improve the activity and stability of the catalyst.

[0025] (2) The organic matter in the acetylacetone salt precursor can be reduced at high temperature to serve as a carbon matrix, and small-sized Ir nanoparticles can be loaded together with related supports. This results in a smaller mass transfer resistance for the catalyst in practical applications and greatly improves the utilization rate of the precious nanoparticles, leading to higher effective catalytic performance in applications. When the current density is 10 mA cm⁻¹ -2 At that time, the overpotential of Ir@Ti nanoparticles was only 271 mV (M). load =0.05 mg Ir cm -2 Low Ir load can also effectively alleviate the current Ir resource scarcity problem.

[0026] (3) This invention avoids the formation of byproducts caused by the use of organic solvents, eliminates the need for additional purification steps, and can be easily synthesized at the gram scale. In summary, the method of this invention has the advantages of simple preparation process, universality, no complicated pretreatment process and no addition of other chemical substances, which makes it suitable for large-scale production and has a wider application prospect and engineering significance in commercial production. Attached Figure Description

[0027] Figure 1 This is a low-magnification transmission electron microscope image of the mass-producible Ir@Ti nanopowder catalyst prepared in Example 1.

[0028] Figure 2 This is a high-magnification transmission electron microscope image of the mass-producible Ir@Ti nanopowder catalyst prepared in Example 1.

[0029] Figure 3 The LSV curve is that of the mass-producible Ir@Ti nanopowder catalyst prepared in Example 1. Detailed Implementation

[0030] The following examples further illustrate the present application but should not be construed as limiting the application. Modifications and adaptations of the method, steps or conditions of the application described herein are within the skill of the art and are intended to be within the scope of the application.

[0031] The technical means used in the examples are conventional means known to those skilled in the art, unless otherwise specified.

[0032] Example 1:

[0033] (1) 0.053 mmol (26.26 mg) of acetylacetone iridium, 40 mg of nano-Ti powder were mixed, and 15 mL of anhydrous ethanol and 15 mL of deionized water were added to dissolve the Ir salt precursor. After ultrasonic treatment for 30 min, the mixture was dried using a rotary evaporator. The solid sample was then scraped off from the flask and ground for 10 min to mix the nano-salt precursor and nano-Ti powder. The obtained powder was placed in a porcelain boat and wrapped with copper foil for use;

[0034] (2) The copper foil and the wrapped powder were then placed in a high-pressure furnace, and the temperature was raised to 600°C at a rate of 10°C / min in a nitrogen atmosphere of 1 MPa above standard atmospheric pressure, and then the temperature was kept for 1 h. After that, the temperature was naturally cooled to room temperature, and a black product was obtained;

[0035] Figure 1 The low-magnification transmission electron micrograph of the mass-producible Ir@ nano-Ti powder catalyst is shown, which shows that the overall morphology of the catalyst is Ir nanoparticles supported on nano-Ti powder. The nanoparticles are uniformly loaded on the nano-Ti powder carrier without obvious agglomeration, which can effectively expose the active sites;

[0036] Figure 2 The high-magnification transmission electron micrograph of the mass-producible Ir@ nano-Ti powder catalyst is shown, which shows that the catalyst is composed of Ir nanoparticles supported on nano-Ti powder. As can be seen from the figure, the average particle size of the Ir nanoparticles is less than 5 nm. The small and uniform particle size allows the catalyst to expose a larger electrochemical active area, greatly improving the exposure rate of active sites.

[0037] Then, the obtained mass-producible Ir@ nano-Ti powder catalyst was tested for oxygen evolution reaction (OER) performance in a 150 mL O2-saturated 0.5 mol / L H2SO4 solution using a Shanghai Chenhua CHI760E electrochemical workstation (reversible hydrogen electrode as reference electrode and platinum sheet as counter electrode), as shown in Figure 3 When the current density was 10 mA cm -2 , the overpotential of the Ir@ nano-Ti powder was only 271 mV (M load = 0.05 mg Ir cm-2 ).

[0038] Example 2:

[0039] (1) 1.072 mol (0.525 g) of acetylacetone iridium, 0.8 g of nano-Ti powder were mixed, and 300 mL of anhydrous ethanol and 300 mL of deionized water were added to dissolve the Ir salt precursor. After ultrasonic treatment for 30 min, the mixture was dried by rotary evaporation, and then the solid sample was scraped off from the flask and ground for 10 min to mix the nano-salt precursor and nano-Ti powder. The obtained powder was placed in a porcelain boat and wrapped with copper foil for standby;

[0040] Then the copper foil and the wrapped powder were placed in a high-pressure furnace, and the temperature was raised to 600°C at a rate of 10°C / min under a nitrogen atmosphere of 1 MPa higher than standard atmospheric pressure, and then the temperature was kept for 1 h. After natural cooling to room temperature, a black product was obtained, and the yield was very high;

[0041] Example 3:

[0042] (1) 0.053 mmol (26.26 mg) of acetylacetone iridium, 40 mg of ITO were mixed, and 15 mL of anhydrous ethanol and 15 mL of deionized water were added to dissolve the Ir salt precursor. After ultrasonic treatment for 30 min, the mixture was dried by rotary evaporation, and then the solid sample was scraped off from the flask and ground for 10 min to mix the nano-salt precursor and nano-Ti powder. The obtained powder was placed in a porcelain boat and wrapped with copper foil for standby;

[0043] (2) Then the copper foil and the wrapped powder were placed in a high-pressure furnace, and the temperature was raised to 650°C at a rate of 10°C / min under a nitrogen atmosphere of 2 MPa higher than standard atmospheric pressure, and then the temperature was kept for 5 h. After natural cooling to room temperature, a black product was obtained;

[0044] Example 4:

[0045] (1) 0.053 mmol (26.26 mg) of acetylacetone iridium, 40 mg of ATO were mixed, and 15 mL of anhydrous ethanol and 15 mL of deionized water were added to dissolve the Ir salt precursor. After ultrasonic treatment for 30 min, the mixture was dried by rotary evaporation, and then the solid sample was scraped off from the flask and ground for 10 min to mix the nano-salt precursor and nano-Ti powder. The obtained powder was placed in a porcelain boat and wrapped with copper foil for standby;

[0046] (2) Then the copper foil and the wrapped powder were placed in a high-pressure furnace, and the temperature was raised to 650°C at a rate of 10°C / min under a nitrogen atmosphere of 5 MPa higher than standard atmospheric pressure, and then the temperature was kept for 2 h. After natural cooling to room temperature, a black product was obtained;

[0047] Example 5:

[0048] (1) 0.053 mmol (26.26 mg) of acetylacetone iridium, 50 mg of nano-Ti powder were mixed, and 15 mL of anhydrous ethanol and 15 mL of deionized water were added to dissolve the Ir salt precursor. After ultrasonic treatment for 30 min, the mixture was dried by a rotary evaporator, and then the solid sample was scraped off from the flask and ground for 10 min. The nano-salt precursor and nano-Ti powder were mixed well, and the obtained powder was placed in a porcelain boat and wrapped with copper foil for standby;

[0049] (2) Then the copper foil together with the wrapped powder was put into a high-pressure furnace, and the temperature was raised to 800°C at a rate of 10°C / min under a nitrogen atmosphere of 5 MPa higher than standard atmospheric pressure, and then kept for 1 h, and then naturally cooled to room temperature to obtain a black product;

[0050] Example 6:

[0051] (1) 0.053 mmol (26.26 mg) of acetylacetone iridium, 40 mg of ATO were mixed, and 15 mL of anhydrous ethanol and 15 mL of deionized water were added to dissolve the Ir salt precursor. After ultrasonic treatment for 30 min, the mixture was dried by a rotary evaporator, and then the solid sample was scraped off from the flask and ground for 10 min. The nano-salt precursor and nano-Ti powder were mixed well, and the obtained powder was placed in a porcelain boat and wrapped with copper foil for standby;

[0052] (2) Then the copper foil together with the wrapped powder was put into a high-pressure furnace, and the temperature was raised to 700°C at a rate of 10°C / min under a nitrogen atmosphere of 10 MPa higher than standard atmospheric pressure, and then kept for 5 h, and then naturally cooled to room temperature to obtain a black product;

[0053] Example 7:

[0054] (1) 0.053 mmol (26.26 mg) of acetylacetone iridium, 40 mg of ATO were mixed, and 15 mL of anhydrous ethanol and 15 mL of deionized water were added to dissolve the Ir salt precursor. After ultrasonic treatment for 30 min, the mixture was dried by a rotary evaporator, and then the solid sample was scraped off from the flask and ground for 10 min. The nano-salt precursor and nano-Ti powder were mixed well, and the obtained powder was placed in a porcelain boat and wrapped with copper foil for standby;

[0055] (2) Then the copper foil together with the wrapped powder was put into a high-pressure furnace, and the temperature was raised to 900°C at a rate of 10°C / min under a nitrogen atmosphere of 2 MPa higher than standard atmospheric pressure, and then kept for 1 h, and then naturally cooled to room temperature to obtain a black product;

[0056] The details of the application not described herein are known.

Claims

1. A method for preparing mass-producible Ir-based supported water electrolysis catalysts, characterized in that, The method comprises the following steps: (1) adding an organic Ir salt precursor and a carrier into a mixed solvent, mixing, ultrasonic stirring for 20-40 minutes, drying and grinding to obtain a mixed powder; The mixed solvent is composed of anhydrous ethanol / deionized water; 0.01 mmol-0.1 mmol of the organic Ir salt precursor is added into 10 ml of the mixed solvent; the mass ratio of the organic Ir salt precursor to the carrier is 1:1.6-25:1; The organic Ir salt precursor is acetylacetone salt; The carrier is one of nano-Ti powder, indium tin oxide (ITO) and antimony-doped tin oxide graphite (ATO); the size of the carrier is 10-200 nm; (2) moving the mixed powder obtained in the above step into a high-pressure furnace, heating to 500-1000 DEG C, annealing under an inert atmosphere for 0.5-48 h, and obtaining an Ir-based supported water electrolysis catalyst that can be mass-produced after cooling to room temperature; The pressure of the inert atmosphere is higher than 0.1 MPa-10 MPa of standard atmospheric pressure.

2. The mass-productive preparation method of Ir-based supported water electrolysis catalyst according to claim 1, characterized in that, The volume ratio of the mixed solvent anhydrous ethanol / deionized water is 1:2-2:

1.

3. The method of claim 1, wherein the method is characterized in that, The inert gas is argon or nitrogen.

4. The mass-productive preparation method of Ir-based supported water electrolysis catalyst according to claim 1, characterized in that, The drying method of the mixed solution in step (1) is a rotary evaporation solvent drying method or a blast oven drying method, and the solid powder is ground for 5-10 minutes after drying.

5. The mass-productive preparation method of Ir-based supported water electrolysis catalyst according to claim 1, characterized in that, The heat treatment annealing temperature in step (2) is 600-800 DEG C, the inert atmosphere pressure is higher than 0.1 MPa-10 MPa of standard atmospheric pressure, the heating rate is 1 DEG C / min-50 DEG C / min, and the annealing time is 1 h-24 h.

6. The mass-productive preparation method of Ir-based supported water electrolysis catalyst according to claim 1, characterized in that, The catalyst comprises a carrier and small-size Ir nanoparticles supported on the carrier; the Ir-based nanoparticle loading is 20wt%-90wt%; the average particle size of the small-size Ir nanoparticles is 1-10 nm; and the particle size of the carrier is 10-200 nm.

7. The mass-productive preparation method of Ir-based supported water electrolysis catalyst according to claim 1, characterized in that, With the increase of the pressure of the inert gas, the particle size of the Ir nanoparticles shows a downward trend.

8. The mass-productive preparation method of Ir-based supported water electrolysis catalyst according to claim 1, characterized in that, The yield of the catalyst reaches the gram level.

9. Use of the Ir-based supported water electrolysis catalyst prepared according to the method of claim 1, characterized in that, The catalyst is used as an anode catalyst in an electrolytic cell.

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