A PEM electrolytic water oxygen evolution catalyst based on atomic layer deposition method and its preparation method

Abstract

The present invention belongs to the technical field of electrolytic water oxygen evolution catalysts, and particularly relates to a PEM electrolytic water oxygen evolution catalyst based on atomic layer deposition and a preparation method thereof. In the present invention, a comb-shaped polymer is used as a template and a structure guiding agent, potassium hydroxide is used as a precipitating agent, and stannous chloride is used as a tin source. During the stirring and mixing process, Sn<supgt;2+< / supgt; is uniformly distributed in the comb-shaped molecular chains of the comb-shaped polymer. Through hydrothermal reaction and high-temperature calcination, porous nano-tin dioxide with a high specific surface area is obtained. Using the porous nano-tin dioxide with a high specific surface area as a carrier, through atomic layer deposition, iridium atoms are uniformly dispersed on the surface of the porous nano-tin dioxide, which can expose more catalytic sites, is beneficial to reducing the overpotential of electrolytic water oxygen evolution, and exhibits good catalytic activity for electrolytic water oxygen evolution.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrolytic water oxygen evolution catalysts, and particularly relates to a PEM electrolytic water oxygen evolution catalyst based on atomic layer deposition and a preparation method thereof. Background Art

[0002] As a clean energy source with high energy density and high combustion efficiency, hydrogen has great development and application prospects. PEM proton exchange membrane water electrolysis for hydrogen production is the current research and development trend. The electrolytic water hydrogen production reaction includes a cathode hydrogen evolution reaction and an anode oxygen evolution reaction. Among them, the anode oxygen evolution reaction has a relatively large overpotential, requires more electrical energy consumption, and results in a low energy conversion rate during the hydrogen production reaction process. Therefore, it is necessary to reduce the overpotential of the oxygen evolution reaction to promote the electrolytic water hydrogen production reaction. Currently, the main oxygen evolution reaction catalysts are noble metal catalysts such as iridium, ruthenium, and platinum. Using metal oxides, molecular sieves, etc. as carriers to load catalysts such as iridium can improve the dispersion of the catalysts, which is beneficial to providing more catalytic active centers and improving the utilization rate and catalytic activity of noble metal catalysts.

[0003] Tin dioxide has excellent electrochemical properties, good structural stability, and a simple preparation method, and has been widely used in fields such as photocatalysis and electrocatalysis. However, the specific surface area of tin dioxide is relatively small, which is not conducive to the loading of catalysts and limits its practical application in catalyst carriers such as electrolytic water hydrogen production. When preparing inorganic compounds, adding template agents and structure-directing agents such as polyvinylpyrrolidone, polyethylene glycol, and comb-shaped polymers can regulate the morphology of inorganic compounds and increase the specific surface area. Atomic layer deposition is a method of depositing substances on the surface of a substrate in the form of a single atomic layer, with advantages such as uniform deposition layer thickness, high consistency, and a thickness in the nanometer order of magnitude. The present invention uses atomic layer deposition to use porous nano-tin dioxide as a catalyst carrier to load an iridium catalyst to obtain a highly catalytically active electrolytic water oxygen evolution catalyst. Summary of the Invention

[0004] The technical problem solved by the present invention is: to provide a PEM electrolytic water oxygen evolution catalyst based on atomic layer deposition with a high specific surface area and high catalytic activity and a preparation method thereof, which solves the problem of relatively low electrolytic water oxygen evolution activity of traditional iridium catalysts.

[0005] The technical solution provided by the present invention is: a preparation method of a PEM electrolytic water oxygen evolution catalyst based on atomic layer deposition:

[0006] S1. Add water, stannous chloride, and a comb-shaped polymer template agent to a reaction vessel, stir and mix evenly, add potassium hydroxide, then pour the solution into a hydrothermal reaction kettle for reaction, filter after cooling, wash successively with water and ethanol, dry, and then calcine in an electric resistance furnace and cool to obtain porous nano-tin dioxide.

[0007] S2. Add water and porous nano-tin dioxide into a container, disperse them by ultrasonic treatment, then pour the solution onto the surface of a quartz glass substrate, dry to remove water, and then place it in the chamber of an atomic layer deposition equipment. Put iridium acetylacetonate in the heat source bottle of the atomic layer deposition equipment, use nitrogen as the purge gas to carry iridium acetylacetonate into the chamber, and carry out the atomic layer deposition process to obtain a PEM electrolytic water oxygen evolution catalyst based on the atomic layer deposition method.

[0008] Further, in S1, the mass of the comb-shaped polymer template agent is 3-15% of the mass of tin dichloride.

[0009] Further, in S1, control the mass concentration of potassium hydroxide in the solution to be 20-30 g / L.

[0010] Further, in S1, the temperature for stirring and mixing is 20-35 °C, and the time is 1-3 h.

[0011] Further, in S1, the reaction temperature is 170-200 °C, and the time is 10-18 h.

[0012] Further, in S1, the calcination temperature is 650-750 °C, and the time is 2-3 h.

[0013] Further, in S2, the temperature of the quartz glass substrate is 320-380 °C; the pressure in the chamber is 0.2-0.5 kPa.

[0014] Further, the cycle process of atomic layer deposition in S2 is as follows: the pulse time of iridium acetylacetonate is 1-4 s, the pulse time of oxygen is 0.03-0.15 s, the nitrogen purge time is 10-15 s; the cycle period is 10-200 times; the flow rate of nitrogen purge is 400-700 mL / min.

[0015] Further, the preparation method of the comb-shaped polymer template agent is as follows:

[0016] (1). Add N,N-dimethylformamide, polyethylene glycol with a molar ratio of 1:(0.9-1.1):(0.1-0.13), N-Boc-glutamic acid, and p-toluenesulfonic acid into a reaction container, stir and react at 80-100 °C for 12-18 h, distill off N,N-dimethylformamide and low-boiling substances under reduced pressure, wash with petroleum ether, add the product to an ethyl acetate solution of hydrogen chloride with a molar concentration of 3.5 mol / L, carry out the reaction and then distill off under reduced pressure, wash with petroleum ether, and dry to obtain an amino-functionalized polyester.

[0017] (2) Add N,N-dimethylformamide, amino-functionalized polyester, methoxypolyethylene glycol acyl chloride, and triethylamine with a mass ratio of 1:(2.4 - 8):(0.3 - 1) into the reaction vessel, stir and react at 20 - 40 °C for 18 - 36 h, carry out vacuum distillation, wash with petroleum ether, and dry to obtain a comb-shaped polymer template agent.

[0018] The present invention also provides a PEM electrolytic water oxygen evolution catalyst based on atomic layer deposition prepared according to the above preparation method.

[0019] The present invention has the following technical effects: The present invention uses p-toluenesulfonic acid as a catalyst to carry out an esterification polymerization reaction between polyethylene glycol and N-Boc-glutamic acid, and then removes the Boc protecting group in an ethyl acetate system of hydrogen chloride to obtain a polyester with amino groups in the side chain. Further, an amidation reaction is carried out with methoxypolyethylene glycol acyl chloride, so that a polyethylene glycol molecular chain is introduced into the side chain. The obtained comb-shaped polymer template agent has a unique comb-shaped structure with a polyethylene glycol polyester as the main chain and polyethylene glycol molecular chains as the side chains.

[0020] The present invention uses a comb-shaped polymer as a template and a structure-directing agent, potassium hydroxide as a precipitating agent, and stannous dichloride as a tin source. During the stirring and mixing process, Sn 2+ is uniformly dispersed in the comb-shaped molecular chains of the comb-shaped polymer. Through hydrothermal reaction and high-temperature calcination, porous nano-tin dioxide with a high specific surface area is obtained.

[0021] The present invention uses porous nano-tin dioxide with a high specific surface area as a carrier. Through atomic layer deposition, iridium atoms are uniformly dispersed on the surface of the porous nano-tin dioxide to form an iridium thin film layer with a larger area and a uniform thickness, which can expose more catalytic sites, is beneficial to reducing the overpotential of electrolytic water oxygen evolution, and exhibits good electrolytic water oxygen evolution catalytic activity. Description of the Drawings

[0022] Figure 1 is the preparation reaction formula of the amino-functionalized polyester.

[0023] Figure 2 is the preparation reaction formula of the comb-shaped polymer template agent.

[0024] Figure 3 is the scanning electron microscope image of the porous nano-tin dioxide. Detailed Embodiments

[0025] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] The structural formula of methoxypolyethylene glycol acyl chloride is as follows: . Preparation was carried out according to the method in the journal "Journal of the Chinese Cereals and Oils Association", May 2015, Vol. 30, No. 5, the literature "Preparation and Properties of Soybean Phosphatidylethanolamine - Methoxypolyethylene Glycol 2000".

[0027] Add 5 g of methoxypolyethylene glycol 2000, 100 mL of acetone, and 4.25 mL of Jones reagent (aqueous solution prepared from chromium trioxide, sulfuric acid and water) to the reaction vessel, react for 24 h, separate, and obtain carboxylated methoxypolyethylene glycol 2000.

[0028] Add 2 g of carboxylated methoxypolyethylene glycol 2000, 10 mL of dichloromethane, and 20 mL of thionyl chloride to the reaction vessel, reflux and react under condensation at 75 °C for 6 h, separate, and obtain methoxypolyethylene glycol acyl chloride.

[0029] Example 1

[0030] (1). Add 50 mL of N,N-dimethylformamide, 3 mmol of polyethylene glycol 400, 2.7 mmol of N-Boc-glutamic acid (CAS No. 2419-94-5), and 0.3 mmol of p-toluenesulfonic acid to the reaction vessel, stir and react at 100 °C for 12 h, distill off N,N-dimethylformamide and low-boiling substances under reduced pressure, wash with petroleum ether, add the product to 8 mL of ethyl acetate solution of hydrogen chloride with a molar concentration of 3.5 mol / L, distill under reduced pressure after reaction, wash with petroleum ether, dry, and obtain amino-functionalized polyester.

[0031] (2). Add 40 mL of N,N-dimethylformamide, 0.5 g of amino-functionalized polyester, 2.6 g of methoxypolyethylene glycol acyl chloride, and 0.3 g of triethylamine to the reaction vessel, stir and react at 20 °C for 36 h, distill under reduced pressure, wash with petroleum ether, dry, and obtain a comb-shaped polymer template agent.

[0032] (3). Add 400 mL of water, 5 g of stannous dichloride, and 0.15 g of the comb-shaped polymer template agent to the reaction vessel, stir and mix evenly at 35 °C for 1 h, add potassium hydroxide, control the mass concentration of potassium hydroxide in the solution to be 30 g / L, then pour the solution into a hydrothermal reaction kettle, react at 200 °C for 10 h, filter after cooling, wash successively with water and ethanol, dry, then in an electric resistance furnace, heat up to 750 °C, calcine for 2 h, cool, and obtain porous nano-tin dioxide.

[0033] (4) Add 300 mL of water and 3 g of porous nano-tin dioxide into a container, disperse it by ultrasonic wave, then pour the solution onto the surface of a quartz glass substrate, dry it to remove water, and then place it in the cavity of an atomic layer deposition equipment. Put iridium acetylacetonate in the heat source bottle of the atomic layer deposition equipment, use nitrogen as the purge gas with a purge flow rate of 700 mL / min, carry iridium acetylacetonate into the cavity, and carry out the atomic layer deposition process. Control the temperature of the quartz glass substrate at 350 °C; the pressure in the cavity is 0.2 kPa; the cycle process of atomic layer deposition is: the pulse time of iridium acetylacetonate is 2 s, the pulse time of oxygen is 0.1 s, and the nitrogen purge time is 10 s; the cycle period is 10 times to obtain a PEM electrolytic water oxygen evolution catalyst based on the atomic layer deposition method.

[0034] Example 2

[0035] (1) Add 60 mL of N,N-dimethylformamide, 3 mmol of polyethylene glycol 600, 3.3 mmol of N-Boc-glutamic acid (CAS No. 2419-94-5), and 0.39 mmol of p-toluenesulfonic acid into a reaction vessel, stir and react at 80 °C for 18 h, distill off N,N-dimethylformamide and low-boiling substances under reduced pressure, wash with petroleum ether, add the product to 10 mL of an ethyl acetate solution of hydrogen chloride with a molar concentration of 3.5 mol / L, distill under reduced pressure after reaction, wash with petroleum ether, and dry to obtain an amino-functionalized polyester.

[0036] (2) Add 50 mL of N,N-dimethylformamide, 0.5 g of amino-functionalized polyester, 4 g of methoxypolyethylene glycol acyl chloride, and 0.5 g of triethylamine into a reaction vessel, stir and react at 40 °C for 18 h, distill under reduced pressure, wash with petroleum ether, and dry to obtain a comb-shaped polymer template agent.

[0037] (3) Add 600 mL of water, 5 g of stannous chloride, and 0.15 g of comb-shaped polymer template agent into a reaction vessel, stir and mix evenly at 20 °C for 3 h, add potassium hydroxide, control the mass concentration of potassium hydroxide in the solution at 20 g / L, then pour the solution into a hydrothermal reaction kettle, react at 170 °C for 18 h, cool and filter, wash successively with water and ethanol, dry, and then heat up to 700 °C in an electric resistance furnace, calcine for 2 h, and cool to obtain porous nano-tin dioxide.

[0038] (4) Add 300 mL of water and 3 g of porous nano-tin dioxide into a container, disperse it by ultrasonic wave, then pour the solution onto the surface of a quartz glass substrate, dry it to remove water, and then place it in the cavity of an atomic layer deposition device. Put iridium acetylacetonate in the heat source bottle of the atomic layer deposition device, use nitrogen as the purge gas, and the purge flow rate is 400 mL / min. Carry iridium acetylacetonate into the cavity to carry out the atomic layer deposition process, and control the temperature of the quartz glass substrate to be 320 °C; the pressure in the cavity is 0.5 kPa; the cycle process of atomic layer deposition is: the pulse time of iridium acetylacetonate is 4 s, the pulse time of oxygen is 0.15 s, and the nitrogen purge time is 15 s; the cycle period is 10 times to obtain a PEM electrolytic water oxygen evolution catalyst based on the atomic layer deposition method.

[0039] Example 3

[0040] (1) Add 70 mL of N,N-dimethylformamide, 3 mmol of polyethylene glycol 800, 3.3 mmol of N-Boc-glutamic acid (CAS No. 2419-94-5), and 0.39 mmol of p-toluenesulfonic acid into a reaction container, stir and react at 90 °C for 18 h, distill off N,N-dimethylformamide and low-boiling substances under reduced pressure, wash with petroleum ether, add the product to 10 mL of an ethyl acetate solution of hydrogen chloride with a molar concentration of 3.5 mol / L, distill under reduced pressure after the reaction, wash with petroleum ether, and dry to obtain an amino-functionalized polyester.

[0041] (2) Add 20 mL of N,N-dimethylformamide, 0.5 g of amino-functionalized polyester, 1.2 g of polyethylene glycol monomethyl ether acyl chloride, and 0.15 g of triethylamine into a reaction container, stir and react at 20 °C for 24 h, distill under reduced pressure, wash with petroleum ether, and dry to obtain a comb-shaped polymer template agent.

[0042] (3) Add 600 mL of water, 5 g of stannous chloride, and 0.15 g of comb-shaped polymer template agent into a reaction container, stir and mix evenly at 35 °C for 1 h, add potassium hydroxide, control the mass concentration of potassium hydroxide in the solution to be 20 g / L, then pour the solution into a hydrothermal reaction kettle, react at 180 °C for 12 h, filter after cooling, wash with water and ethanol in turn, dry, and then heat up to 650 °C in an electric resistance furnace, calcine for 3 h, and cool to obtain porous nano-tin dioxide.

[0043] (4) Add 300 mL of water and 3 g of porous nano-tin dioxide into a container, disperse them by ultrasonic treatment, then pour the solution onto the surface of a quartz glass substrate, dry to remove water, and then place it in the cavity of an atomic layer deposition equipment. Put iridium acetylacetonate in the heat source bottle of the atomic layer deposition equipment, use nitrogen as the purge gas, and the purge flow rate is 400 mL / min. Carry iridium acetylacetonate into the cavity to carry out the atomic layer deposition process. Control the temperature of the quartz glass substrate to be 380 °C; the pressure in the cavity is 0.2 kPa; the cycle process of atomic layer deposition is: the pulse time of iridium acetylacetonate is 1 s, the pulse time of oxygen is 0.03 s, and the nitrogen purge time is 15 s; the cycle period is 10 times to obtain a PEM electrolytic water oxygen evolution catalyst based on the atomic layer deposition method.

[0044] Comparative Example 1

[0045] The difference between Comparative Example 1 and Example 3 is that when preparing tin dioxide, no comb-shaped polymer template agent is added.

[0046] (1) Add 600 mL of water and 5 g of tin dichloride into a reaction container, stir and mix evenly at 35 °C for 1 h, add potassium hydroxide, control the mass concentration of potassium hydroxide in the solution to be 20 g / L, then pour the solution into a hydrothermal reaction kettle, react at 180 °C for 12 h, cool and filter, wash successively with water and ethanol, dry, and then in an electric resistance furnace, heat up to 650 °C, calcine for 3 h, and cool to obtain tin dioxide.

[0047] (2) Add 300 mL of water and 3 g of tin dioxide into a container, disperse them by ultrasonic treatment, then pour the solution onto the surface of a quartz glass substrate, dry to remove water, and then place it in the cavity of an atomic layer deposition equipment. Put iridium acetylacetonate in the heat source bottle of the atomic layer deposition equipment, use nitrogen as the purge gas, and the purge flow rate is 400 mL / min. Carry iridium acetylacetonate into the cavity to carry out the atomic layer deposition process. Control the temperature of the quartz glass substrate to be 380 °C; the pressure in the cavity is 0.2 kPa; the cycle process of atomic layer deposition is: the pulse time of iridium acetylacetonate is 1 s, the pulse time of oxygen is 0.03 s, and the nitrogen purge time is 15 s; the cycle period is 10 times to obtain a PEM electrolytic water oxygen evolution catalyst based on the atomic layer deposition method.

[0048] Comparative Example 2

[0049] The difference between Comparative Example 2 and Example 3 is that when preparing tin dioxide, polyethylene glycol 800 is used instead of the comb-shaped polymer template agent.

[0050] (1) Add 600 mL of water, 5 g of stannous chloride, and 0.15 g of polyethylene glycol 800 to a reaction vessel, stir and mix evenly at 35 °C for 1 h, add potassium hydroxide, control the mass concentration of potassium hydroxide in the solution to be 20 g / L, then pour the solution into a hydrothermal reaction kettle, react at 180 °C for 12 h, cool and filter, wash successively with water and ethanol, dry, and then in an electric resistance furnace, heat up to 650 °C, calcine for 3 h, cool to obtain tin dioxide.

[0051] (2) Add 300 mL of water and 3 g of tin dioxide to a container, disperse by ultrasonic wave, then pour the solution onto the surface of a quartz glass substrate, dry to remove water, and then place it in the cavity of an atomic layer deposition device. Put iridium acetylacetonate in the heat source bottle of the atomic layer deposition device, use nitrogen as the purge gas, and the purge flow rate is 400 mL / min. Carry iridium acetylacetonate into the cavity to carry out the atomic layer deposition process, control the temperature of the quartz glass substrate to be 380 °C; the pressure in the cavity is 0.2 kPa; the cycle process of atomic layer deposition is: the pulse time of iridium acetylacetonate is 1 s, the pulse time of oxygen is 0.03 s, and the nitrogen purge time is 15 s; the cycle period is 10 times to obtain a PEM electrolytic water oxygen evolution catalyst based on the atomic layer deposition method.

[0052] Comparative Example 3

[0053] The difference between Comparative Example 3 and Example 3 is that when preparing tin dioxide, an amino-functionalized polyester is used instead of a comb-shaped polymer template agent.

[0054] (1) Add 600 mL of water, 5 g of stannous chloride, and 0.15 g of amino-functionalized polyester to a reaction vessel, stir and mix evenly at 35 °C for 1 h, add potassium hydroxide, control the mass concentration of potassium hydroxide in the solution to be 20 g / L, then pour the solution into a hydrothermal reaction kettle, react at 180 °C for 12 h, cool and filter, wash successively with water and ethanol, dry, and then in an electric resistance furnace, heat up to 650 °C, calcine for 3 h, cool to obtain tin dioxide.

[0055] (2) Add 300 mL of water and 3 g of tin dioxide to a container, disperse by ultrasonic wave, then pour the solution onto the surface of a quartz glass substrate, dry to remove water, and then place it in the cavity of an atomic layer deposition device. Put iridium acetylacetonate in the heat source bottle of the atomic layer deposition device, use nitrogen as the purge gas, and the purge flow rate is 400 mL / min. Carry iridium acetylacetonate into the cavity to carry out the atomic layer deposition process, control the temperature of the quartz glass substrate to be 380 °C; the pressure in the cavity is 0.2 kPa; the cycle process of atomic layer deposition is: the pulse time of iridium acetylacetonate is 1 s, the pulse time of oxygen is 0.03 s, and the nitrogen purge time is 15 s; the cycle period is 10 times to obtain a PEM electrolytic water oxygen evolution catalyst based on the atomic layer deposition method.

[0056] The specific surface area of tin dioxide was tested using a fully automatic physical adsorption / chemical adsorption analyzer. Before the test, nitrogen adsorption-desorption treatment was carried out with liquid nitrogen at a temperature of 200 °C.

[0057] An oxygen evolution catalyst for electrolytic water and isopropanol were added to the Nafion solution, and ultrasonic dispersion was carried out. Then the slurry was sprayed on one side of the Nafion-117 membrane and dried. The loading amount of the oxygen evolution catalyst for electrolytic water on the membrane surface was controlled to be 3 mg / cm -2 ; A Pt / C catalyst and isopropanol were added to the Nafion solution, and ultrasonic dispersion was carried out. The slurry was sprayed on the other side of the Nafion-117 membrane and dried. The loading amount of the Pt / C catalyst on the membrane surface was controlled to be 1 mg / cm -2 . A CCM membrane electrode was obtained. Carbon paper with a diffusion layer (PTFE + carbon powder) was covered on both sides of the CCM membrane electrode, and hot pressing was carried out at 150 °C under a pressure of 10 MPa for 10 min to obtain a MEA membrane electrode.

[0058] The MEA membrane electrode was fixed in the electrolytic cell clamp and assembled into an electrolytic cell for testing the performance of electrolytic water. A positive voltage was applied to the oxygen evolution catalyst electrode for electrolytic water, and a negative voltage was applied to the Pt / C electrode. Electrolytic water tests were carried out in distilled water at a test temperature of 25 °C.

[0059] The test results are shown in Table 1.

[0060] Table 1 Specific surface area of tin dioxide and performance test of oxygen evolution catalyst

[0061]

[0062] As can be seen from Table 1, when preparing tin dioxide in Comparative Example 1, no template agent was added, the dispersion of tin dioxide was very poor, the pore structure was very few, the total pore volume was only 0.009, and the specific surface area was small, only 6.92 m 2 / g. As a result, during the atomic layer deposition process, iridium atoms were not evenly loaded onto the surface of the tin dioxide support, there were fewer catalytic sites, and the catalytic performance of electrolytic water was poor. The oxygen evolution overpotential at a current density of 20 mA / cm -2 reached 183.6 mV. The larger the oxygen evolution overpotential, the lower the oxygen evolution activity.

[0063] In Comparative Example 2, polyethylene glycol was used as the template agent, and in Comparative Example 3, amino-functionalized polyester was used as the template agent. Neither of them contains a comb structure, and the structure-directing property for tin dioxide is poor, resulting in a lower specific surface area and total pore volume of the obtained tin dioxide.

[0064] In Examples 1-3, a comb-shaped polymer template agent was added during the preparation of tin dioxide. The template agent uses polyethylene glycol polyester as the main chain, and the side chain contains polyethylene glycol molecular chains, forming a unique comb-shaped structure. Using it as a template and structure guiding agent, Sn 2+ is evenly distributed in the comb-shaped molecular chains of the comb-shaped polymer. Through hydrothermal reaction and high-temperature calcination, porous nano-tin dioxide with a high specific surface area is obtained. Using it as a carrier, through atomic layer deposition, iridium atoms are evenly dispersed on the surface of the porous nano-tin dioxide, forming an iridium thin film layer with a larger area and uniform thickness, which can expose more catalytic sites. The oxygen evolution overpotential at a current density of 20 mA / cm -2 is only 145.4 - 153.0 mV, showing good catalytic activity for electrolytic water oxygen evolution.

[0065] Example 4

[0066] The difference between Example 4 and Example 3 is that the dosage of the comb-shaped polymer template agent is 0.35 g.

[0067] (1). Add 600 mL of water, 5 g of stannous chloride, and 0.35 g of the comb-shaped polymer template agent to the reaction vessel, stir and mix evenly at 35 °C for 1 h, add potassium hydroxide, control the mass concentration of potassium hydroxide in the solution to be 20 g / L, then pour the solution into a hydrothermal reaction kettle, react at 180 °C for 12 h, cool and filter, wash with water and ethanol in sequence, dry, and then in an electric resistance furnace, heat up to 650 °C, calcine for 3 h, cool to obtain porous nano-tin dioxide.

[0068] (2). Add 300 mL of water and 3 g of porous nano-tin dioxide to the container, disperse by ultrasonic, then pour the solution on the surface of a quartz glass substrate, dry to remove water, and then place it in the cavity of an atomic layer deposition device. Put iridium acetylacetonate in the heat source bottle of the atomic layer deposition device, use nitrogen as the purge gas, and the purge flow rate is 400 mL / min. Carry iridium acetylacetonate into the cavity to carry out the atomic layer deposition process, control the temperature of the quartz glass substrate to be 380 °C; the pressure in the cavity is 0.2 kPa; the cycle process of atomic layer deposition is: the pulse time of iridium acetylacetonate is 1 s, the pulse time of oxygen is 0.03 s, and the nitrogen purge time is 15 s; the cycle period is 10 times to obtain a PEM electrolytic water oxygen evolution catalyst based on atomic layer deposition.

[0069] Example 5

[0070] The difference between Example 5 and Example 3 is that the dosage of the comb-shaped polymer template agent is 0.55 g.

[0071] (1) Add 600 mL of water, 5 g of stannous chloride, and 0.55 g of comb-shaped polymer template agent to a reaction vessel, stir and mix evenly at 35 °C for 1 h, add potassium hydroxide, control the mass concentration of potassium hydroxide in the solution to be 20 g / L, then pour the solution into a hydrothermal reaction kettle, react at 180 °C for 12 h, cool and filter, wash successively with water and ethanol, dry, and then in an electric resistance furnace, heat up to 650 °C, calcine for 3 h, cool to obtain porous nano-tin dioxide.

[0072] (2) Add 300 mL of water and 3 g of porous nano-tin dioxide to a container, disperse by ultrasonic, then pour the solution onto the surface of a quartz glass substrate, dry to remove water, and then place it in the cavity of an atomic layer deposition device. Put iridium acetylacetonate in the heat source bottle of the atomic layer deposition device, use nitrogen as the purge gas, and the purge flow rate is 400 mL / min. Carry iridium acetylacetonate into the cavity to carry out the atomic layer deposition process, control the temperature of the quartz glass substrate to be 380 °C; the pressure in the cavity is 0.2 kPa; the cycle process of atomic layer deposition is: the pulse time of iridium acetylacetonate is 1 s, the pulse time of oxygen is 0.03 s, and the nitrogen purge time is 15 s; the cycle period is 10 times to obtain a PEM electrolytic water oxygen evolution catalyst based on the atomic layer deposition method.

[0073] Example 6

[0074] The difference between Example 6 and Example 3 is that the dosage of the comb-shaped polymer template agent is 0.75 g.

[0075] (1) Add 600 mL of water, 5 g of stannous chloride, and 0.75 g of comb-shaped polymer template agent to a reaction vessel, stir and mix evenly at 35 °C for 1 h, add potassium hydroxide, control the mass concentration of potassium hydroxide in the solution to be 20 g / L, then pour the solution into a hydrothermal reaction kettle, react at 180 °C for 12 h, cool and filter, wash successively with water and ethanol, dry, and then in an electric resistance furnace, heat up to 650 °C, calcine for 3 h, cool to obtain porous nano-tin dioxide.

[0076] (2) Add 300 mL of water and 3 g of porous nano-tin dioxide to a container, disperse by ultrasonic, then pour the solution onto the surface of a quartz glass substrate, dry to remove water, and then place it in the cavity of an atomic layer deposition device. Put iridium acetylacetonate in the heat source bottle of the atomic layer deposition device, use nitrogen as the purge gas, and the purge flow rate is 400 mL / min. Carry iridium acetylacetonate into the cavity to carry out the atomic layer deposition process, control the temperature of the quartz glass substrate to be 380 °C; the pressure in the cavity is 0.2 kPa; the cycle process of atomic layer deposition is: the pulse time of iridium acetylacetonate is 1 s, the pulse time of oxygen is 0.03 s, and the nitrogen purge time is 15 s; the cycle period is 10 times to obtain a PEM electrolytic water oxygen evolution catalyst based on the atomic layer deposition method.

[0077] The test results are shown in Table 2.

[0078] Table 2 Performance Tests of Tin Dioxide and Oxygen Evolution Catalyst with Different Dosages of Template Agent

[0079]

[0080] After testing, in Example 5, when the dosage of the comb-shaped polymer template agent is 0.55 g (11% of the mass of stannous chloride), the specific surface area and total pore volume of tin dioxide are the largest, reaching 56.91 m 2 / g and 0.142 cm 3 / g. The obtained oxygen evolution catalyst for electrolytic water has an oxygen evolution overpotential of only 141.5 mV at a current density of 20 mA / cm -2 .

[0081] Example 7

[0082] The difference between Example 7 and Example 5 is that the cycle period is 40 times.

[0083] Add 300 mL of water and 3 g of porous nano-tin dioxide to the container, disperse it by ultrasonic wave, then pour the solution on the surface of the quartz glass substrate, dry to remove water, and then place it in the cavity of the atomic layer deposition equipment. Put iridium acetylacetonate in the heat source bottle of the atomic layer deposition equipment. Nitrogen is used as the purge gas, and the purge flow rate is 400 mL / min. Carry iridium acetylacetonate into the cavity to carry out the atomic layer deposition process. Control the temperature of the quartz glass substrate to be 380 °C; the pressure in the cavity is 0.2 kPa; the cycle process of atomic layer deposition is: the pulse time of iridium acetylacetonate is 1 s, the pulse time of oxygen is 0.03 s, and the nitrogen purge time is 15 s; the cycle period is 40 times to obtain a PEM electrolytic water oxygen evolution catalyst based on the atomic layer deposition method.

[0084] Example 8

[0085] The difference between Example 7 and Example 5 is that the cycle period is 70 times.

[0086] Add 300 mL of water and 3 g of porous nano-tin dioxide to the container, disperse it by ultrasonic wave, then pour the solution on the surface of the quartz glass substrate, dry to remove water, and then place it in the cavity of the atomic layer deposition equipment. Put iridium acetylacetonate in the heat source bottle of the atomic layer deposition equipment. Nitrogen is used as the purge gas, and the purge flow rate is 400 mL / min. Carry iridium acetylacetonate into the cavity to carry out the atomic layer deposition process. Control the temperature of the quartz glass substrate to be 380 °C; the pressure in the cavity is 0.2 kPa; the cycle process of atomic layer deposition is: the pulse time of iridium acetylacetonate is 1 s, the pulse time of oxygen is 0.03 s, and the nitrogen purge time is 15 s; the cycle period is 70 times to obtain a PEM electrolytic water oxygen evolution catalyst based on the atomic layer deposition method.

[0087] Example 9

[0088] The difference between Example 7 and Example 5 is that the cycle period is 100 times.

[0089] Add 300 mL of water and 3 g of porous nano-tin dioxide into a container, disperse it by ultrasonic, then pour the solution onto the surface of a quartz glass substrate, dry to remove water, and then place it in the chamber of an atomic layer deposition equipment. Put iridium acetylacetonate in the heat source bottle of the atomic layer deposition equipment, use nitrogen as the purge gas, and the purge flow rate is 400 mL / min. Carry iridium acetylacetonate into the chamber to carry out the atomic layer deposition process. Control the temperature of the quartz glass substrate to be 380 °C; the pressure in the chamber is 0.2 kPa; the cycle process of atomic layer deposition is: the pulse time of iridium acetylacetonate is 1 s, the pulse time of oxygen is 0.03 s, and the nitrogen purge time is 15 s; the cycle period is 100 times to obtain a PEM electrolytic water oxygen evolution catalyst based on the atomic layer deposition method.

[0090] The test results are shown in Table 3.

[0091] Table 3 Oxygen evolution overpotential

[0092]

[0093]

[0094] After testing, in Example 8 and Example 9, when the cycle period of atomic layer deposition is 70 - 100 times, the oxygen evolution overpotential at a current density of 20 mA / cm -2 is only 135.3 mV and 134.9 mV, showing excellent electrolytic water oxygen evolution activity.

Claims

1. A method for preparing a PEM water electrolysis oxygen evolution catalyst based on atomic layer deposition, characterized in that: The preparation method comprises: S1, adding water, tin dichloride, and a comb-type polymer template agent into a reaction container, stirring and mixing, adding potassium hydroxide, and then pouring the solution into a hydrothermal reactor to react, cooling and filtering, washing, drying, and then calcining in a resistance furnace, cooling, and obtaining porous nano-tin dioxide; S2. Add water and porous nano-tin dioxide into the container, disperse it by ultrasound, then pour the solution on the surface of the quartz glass substrate, dry it to remove water, and then place it in the cavity of the atomic layer deposition equipment, place iridium acetylacetonate in the heat source bottle of the atomic layer deposition equipment, use nitrogen as a purge gas to carry the iridium acetylacetonate into the cavity, and perform an atomic layer deposition process to obtain a PEM water electrolysis oxygen evolution catalyst based on the atomic layer deposition method; In S1, the reaction temperature is 170-200°C and the reaction time is 10-18h; The preparation method of the comb-type polymer template agent is: (1) Add N,N-dimethylformamide, polyethylene glycol in a molar ratio of 1:(0.9-1.1):(0.1-0.13), N-Boc-glutamic acid, and p-toluenesulfonic acid to a reaction vessel, stir and react at 80-100° C. for 12-18 hours, distill under reduced pressure, wash, and add the product to an ethyl acetate solution of hydrogen chloride with a molar concentration of 3.5 mol / L. After the reaction, distill under reduced pressure, wash, and dry to obtain an amino polyester; (2) Add N,N-dimethylformamide, amino polyester, polyethylene glycol monomethyl ether chloride and triethylamine in a mass ratio of 1:(2.4-8):(0.3-1) into a reaction container, stir and react at 20-40° C. for 18-36 hours, distill under reduced pressure, wash and dry to obtain a comb-type polymer template agent.

2. The method for preparing a PEM water electrolysis oxygen evolution catalyst based on atomic layer deposition according to claim 1, characterized in that: In the S1, the mass of the comb-type polymer template agent is 3-15% of the mass of tin dichloride.

3. The method for preparing a PEM water electrolysis oxygen evolution catalyst based on atomic layer deposition according to claim 1, characterized in that: In S1, the mass concentration of potassium hydroxide in the solution is controlled to be 20-30 g / L.

4. The method for preparing a PEM water electrolysis oxygen evolution catalyst based on atomic layer deposition according to claim 1, characterized in that: In S1, the stirring and mixing is performed at a temperature of 20-35° C. for 1-3 h.

5. The method for preparing a PEM water electrolysis oxygen evolution catalyst based on atomic layer deposition according to claim 1, characterized in that: In S1, the calcination temperature is 650-750° C. and the calcination time is 2-3 h.

6. The method for preparing a PEM water electrolysis oxygen evolution catalyst based on atomic layer deposition according to claim 1, characterized in that: In S2, an atomic layer deposition process is performed, and the temperature of the quartz glass substrate is controlled to be 320-380°C; the pressure in the cavity is 0.2-0.5 kPa.

7. The method for preparing a PEM water electrolysis oxygen evolution catalyst based on atomic layer deposition according to claim 1, characterized in that: In S2, the cyclic process of atomic layer deposition is: iridium acetylacetonate pulse time is 1-4s, oxygen pulse time is 0.03-0.15s, nitrogen purge time is 10-15s; the cycle period is 10-200 times; the flow rate of nitrogen purge is 400-700mL / min.

8. A PEM water electrolysis oxygen evolution catalyst prepared according to the preparation method of a PEM water electrolysis oxygen evolution catalyst based on atomic layer deposition according to any one of claims 1 to 7.

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