Porous amorphous iridium oxide microsphere as well as preparation method and application thereof

Abstract

The invention belongs to the field of catalysts, and particularly relates to porous amorphous iridium oxide microspheres as well as a preparation method and application thereof. The preparation method provided by the invention comprises the following steps: a) mixing an iridium source compound with a cetyltrimethylammonium bromide aqueous solution with an alkaline pH value, and carrying out a heating reaction under an anaerobic condition to obtain a solid product; and b) mixing the solid product with an acid solution, and carrying out heating treatment to obtain the porous amorphous iridium oxide microspheres. The method is simple in operation process, green and environment-friendly, and good in stability and repeatability; the prepared amorphous iridium oxide microspheres are of a porous structure, uniform in morphology and high in purity, have excellent oxygen evolution reaction activity and stability, can show excellent catalytic performance in a proton exchange membrane (PEM) electrolyzed water system, and have remarkable industrial application value and market popularization prospects.

Description

Technical Field

[0001] The present invention belongs to the field of catalysts, and particularly relates to a porous amorphous iridium oxide microsphere, a preparation method thereof, and an application thereof. Background Art

[0002] Currently, the world is facing the severe challenge of climate change, and promoting the transformation of the energy structure towards green and low-carbon has become the consensus of the international community. In this context, hydrogen, as a clean, efficient, and versatile energy carrier, is gradually becoming one of the core elements of the energy revolution. In the technology of electrolytic water for hydrogen production driven by renewable energy, proton exchange membrane (PEM) electrolytic water adopts a compact modular design, has characteristics such as flexible operation, fast response speed, and low maintenance cost, has good compatibility with intermittent renewable energy, and can efficiently convert renewable energy into high-purity green hydrogen. These characteristics make PEM electrolytic water a key technology to promote the development of the green hydrogen energy economy, provide sustainable solutions for fields such as industry, transportation, and energy storage, and contribute to the realization of the global carbon neutrality goal.

[0003] The anodic oxygen evolution reaction (OER) of PEM electrolytic water is a four-electron transfer process, resulting in slow kinetics and high overpotential, which becomes one of the key factors restricting the improvement of PEM electrolytic water efficiency. At the same time, the anode of the PEM electrolytic cell is in a strong acidic environment and has a high electrolysis voltage, which puts extremely high requirements on the activity and stability of the catalyst. Currently, iridium-based materials are regarded as the most advanced materials for PEM electrolytic water anodic catalysts because of their excellent catalytic activity and long-term stability in a strong acidic environment. However, iridium, as a precious metal, has extremely scarce global reserves and high prices, which greatly increases the cost of hydrogen production by PEM electrolytic water and limits its large-scale commercial application. Therefore, developing low-cost and high-performance iridium-based catalysts has become one of the core research directions to promote the development of PEM electrolytic water technology.

[0004] Increasing the active sites of the catalyst and improving the catalyst utilization rate are key strategies for developing low-cost and high-performance iridium-based catalysts. The porous structure can significantly increase the specific surface area of the catalyst, thereby exposing more active sites and improving the activity of the catalyst.

[0005] Currently, methods for synthesizing porous iridium oxide include using templates or pore-forming agents to guide the porous structure, but there are problems such as difficult template removal and structure collapse. The Adams method is also used to prepare porous iridium oxide, but there are problems such as complex operation, environmental unfriendliness, and, crucially, low purity of the obtained product. Therefore, it is very necessary to develop a simple method for preparing porous iridium oxide catalysts. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a porous amorphous iridium oxide microsphere, a preparation method and an application thereof. The preparation method provided by the present invention has simple steps. The obtained amorphous iridium oxide microspheres are uniformly porous, have high purity, and have excellent oxygen evolution reaction activity and stability.

[0007] The present invention provides a preparation method of a porous amorphous iridium oxide microsphere, comprising the following steps:

[0008] a) Mixing an iridium source compound with an aqueous solution of cetyltrimethylammonium bromide having a basic pH value, and heating and reacting under an anaerobic condition to obtain a solid product;

[0009] b) Mixing the solid product with an acid solution and performing a heat treatment to obtain a porous amorphous iridium oxide microsphere.

[0010] Preferably, in step a), the iridium source compound is one or more of chloroiridic acid, iridium trichloride, iridium acetylacetonate, iridium acetate, and potassium chloroiridate.

[0011] Preferably, in step a), the mass ratio of cetyltrimethylammonium bromide to water in the aqueous solution of cetyltrimethylammonium bromide is (3-5):1; the pH value of the aqueous solution of cetyltrimethylammonium bromide is 10-13.

[0012] Preferably, in step a), the mass ratio of the iridium source compound to cetyltrimethylammonium bromide in the aqueous solution of cetyltrimethylammonium bromide is 1:(3-5).

[0013] Preferably, in step a), the temperature of the heating reaction is 90-120 °C, and the time is 5-8 h.

[0014] Preferably, in step b), before mixing with the acid solution, the solid product is first ground.

[0015] Preferably, in step b), the acid in the acid solution is one or more of sulfuric acid, nitric acid, and hydrochloric acid; the acid concentration of the acid solution is 0.1-1 mol / L.

[0016] Preferably, in step b), the temperature of the heat treatment is 60-90 °C, and the time is 1-4 h.

[0017] The present invention provides a porous amorphous iridium oxide microsphere prepared by the preparation method according to the above technical solution.

[0018] The present invention provides a method for producing hydrogen by proton exchange membrane electrolysis of water, comprising the following steps:

[0019] Using a membrane electrode to electrolyze water to produce hydrogen;

[0020] The membrane electrode includes a proton exchange membrane, a cathode catalyst layer composite on one surface of the proton exchange membrane, and an anode catalyst layer composite on the other surface of the proton exchange membrane; the composition of the anode catalyst layer includes the porous amorphous iridium oxide microspheres described in the above technical solution.

[0021] Compared with the prior art, the present invention provides a porous amorphous iridium oxide microsphere and its preparation method and application. The preparation method provided by the present invention includes the following steps: a) mixing an iridium source compound with an aqueous solution of cetyltrimethylammonium bromide having a basic pH value, and heating and reacting under an anaerobic condition to obtain a solid product; b) mixing the solid product with an acid solution and performing heat treatment to obtain porous amorphous iridium oxide microspheres. This method has a simple operation process, is green and environmentally friendly, and has good stability and repeatability; the prepared amorphous iridium oxide microspheres have a porous structure, uniform morphology, high purity, excellent oxygen evolution reaction activity and stability, can exhibit excellent catalytic performance in a proton exchange membrane (PEM) electrolyzed water system, and have significant industrial application value and market promotion prospects. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0023] Figure 1 It is a TEM image of the amorphous iridium oxide microspheres without acid solution treatment in Example 1 provided by the present invention;

[0024] Figure 2 It is an XRD image of the porous amorphous iridium oxide microspheres obtained after acid solution treatment in Example 1 provided by the present invention;

[0025] Figure 3 It is a TEM image of the porous amorphous iridium oxide microspheres obtained after acid solution treatment in Example 1 provided by the present invention;

[0026] Figure 4 It is a graph showing the test results of the catalytic activity of the amorphous iridium oxide materials prepared in Example 1, Example 2 and Comparative Example 1 of the present invention for PEM electrolysis devices;

[0027] Figure 5 It is a graph showing the test results of the catalytic stability of the porous amorphous iridium oxide microspheres prepared in Example 1 of the present invention for PEM electrolysis devices;

[0028] Figure 6It is a graph showing the test results of the catalytic stability of the porous amorphous iridium oxide microspheres prepared in Example 2 provided by the present invention for PEM electrolysis devices;

[0029] Figure 7 It is a TEM image of the iridium oxide nanoparticles prepared in Comparative Example 1 provided by the present invention;

[0030] Figure 8 It is a graph showing the test results of the catalytic stability of the iridium oxide nanoparticles prepared in Comparative Example 1 provided by the present invention for PEM electrolysis devices. Detailed implementation manners

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. 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.

[0032] The present invention provides a method for preparing porous amorphous iridium oxide microspheres, comprising the following steps:

[0033] a) Mixing an iridium source compound with an aqueous solution of cetyltrimethylammonium bromide having a basic pH value, and heating and reacting under an anaerobic condition to obtain a solid product;

[0034] b) Mixing the solid product with an acid solution and performing a heat treatment to obtain porous amorphous iridium oxide microspheres.

[0035] In the preparation method provided by the present invention, in step a), the iridium source compound is preferably one or more of chloroiridic acid, iridium trichloride, iridium acetylacetonate, iridium acetate, and potassium chloroiridate.

[0036] In the preparation method provided by the present invention, in step a), the mass ratio of cetyltrimethylammonium bromide to water in the aqueous solution of cetyltrimethylammonium bromide is preferably (3-5):1, specifically 3:1, 3.5:1, 4:1, 4.5:1, or 5:1; the pH value of the aqueous solution of cetyltrimethylammonium bromide is preferably 10-13, specifically 10, 10.5, 11, 11.5, 12, 12.5, or 13.

[0037] In the preparation method provided by the present invention, in step a), the aqueous solution of cetyltrimethylammonium bromide is preferably prepared according to the following steps: mixing cetyltrimethylammonium bromide with water and adjusting the pH value of the solution to be basic to obtain an aqueous solution of cetyltrimethylammonium bromide having a basic pH value.

[0038] In the preparation method provided by the present invention, in step a), the mass ratio of the iridium source compound to cetyltrimethylammonium bromide in the aqueous solution of cetyltrimethylammonium bromide is preferably 1:(3-5), specifically 1:3, 1:3.5, 1:4, 1:4.5 or 1:5.

[0039] In the preparation method provided by the present invention, in step a), the anaerobic condition is preferably a nitrogen atmosphere.

[0040] In the preparation method provided by the present invention, in step a), the temperature of the heating reaction is preferably 90-120°C, specifically 90°C, 95°C, 100°C, 105°C, 110°C, 115°C or 120°C; the time of the heating reaction is preferably 5-8 h, specifically 5 h, 5.5 h, 6 h, 6.5 h, 7 h, 7.5 h or 8 h.

[0041] In the preparation method provided by the present invention, in step a), after obtaining the solid product, it is preferably washed and dried.

[0042] In the preparation method provided by the present invention, in step b), before mixing with the acid solution, the solid product is preferably ground first.

[0043] In the preparation method provided by the present invention, in step b), the acid in the acid solution is preferably one or more of sulfuric acid, nitric acid and hydrochloric acid; the acid concentration of the acid solution is preferably 0.1-1 mol / L, specifically 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L or 1 mol / L.

[0044] In the preparation method provided by the present invention, in step b), the temperature of the heat treatment is preferably 60-90°C, specifically 60°C, 65°C, 70°C, 75°C, 80°C, 85°C or 90°C; the time of the heat treatment is preferably 1-4 h, specifically 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h or 4 h.

[0045] In the preparation method provided by the present invention, in step b), after obtaining the porous amorphous iridium oxide microspheres, it is preferably washed and dried.

[0046] The present invention also provides a kind of porous amorphous iridium oxide microspheres, which are prepared by the preparation method according to the above technical scheme.

[0047] The present invention also provides a method for hydrogen production by proton exchange membrane electrolysis of water, comprising the following steps:

[0048] Hydrogen is produced by electrolyzing water using a membrane electrode;

[0049] The membrane electrode includes a proton exchange membrane, a cathode catalyst layer composite on one surface of the proton exchange membrane, and an anode catalyst layer composite on the other surface of the proton exchange membrane; the composition of the anode catalyst layer includes the porous amorphous iridium oxide microspheres described in the above technical solution.

[0050] In the method for producing hydrogen by electrolyzing water provided by the present invention, the composition of the cathode catalyst layer includes a cathode catalyst and a binder; wherein, the cathode catalyst is preferably a platinum-carbon catalyst; the binder is preferably a 5% by mass perfluorosulfonic acid resin solution Nafion D520; the platinum loading of the cathode catalyst layer is 0.1 - 0.5 mg / cm 2 , more preferably 0.3 mg / cm 2 .

[0051] In the method for producing hydrogen by electrolyzing water provided by the present invention, the composition of the anode catalyst layer includes an anode catalyst and a binder; wherein, the anode catalyst is the porous amorphous iridium oxide microspheres; the binder is preferably a 5% by mass perfluorosulfonic acid resin solution Nafion D520; the iridium loading of the anode catalyst layer is 0.2 - 1 mg / cm 2 , more preferably 0.5 mg / cm 2 .

[0052] For clarity, the following will be described in detail through the following examples and comparative examples.

[0053] Example 1

[0054] (1) Synthesis of uniform porous amorphous iridium oxide microspheres, the steps are as follows:

[0055] First, cetyltrimethylammonium bromide and water are mixed evenly at a mass ratio of 3:1 and the pH value of the solution is adjusted to 12. Iridium trichloride is added to the mixed solution, and the mass ratio of iridium trichloride to cetyltrimethylammonium bromide is 1:3. The mixed solution is heated in a constant-temperature oil bath under a nitrogen atmosphere, the heating temperature is 110 °C, and the heating time is 5 h. After the reaction, the obtained product is centrifuged and washed with deionized water and absolute ethanol, and dried in a vacuum oven.

[0056] The obtained product is observed by transmission electron microscopy (TEM), and the results are as Figure 1 shown. Through Figure 1 it can be seen that the microscopic morphology of the product is uniform solid microspheres.

[0057] The product after centrifugal drying is fully ground and then immersed in a nitric acid solution with a concentration of 0.3 mol / L. The mixed solution is transferred to a polytetrafluoroethylene reaction kettle and kept at 80 °C for 3 h. After the reaction system cools to room temperature, the precipitate is obtained by centrifugal separation. After washing and drying, the target product, porous amorphous iridium oxide microspheres, is obtained.

[0058] The prepared porous amorphous iridium oxide microspheres were characterized by X-ray diffraction (XRD), and the results are as Figure 2 shown. It can be seen through Figure 2 that the microspheres are in an amorphous phase.

[0059] The prepared porous amorphous iridium oxide microspheres were observed by TEM, and the results are as Figure 3 shown. It can be seen through Figure 3 that the microspheres have uniform sizes and there are pore structures on the surface of the spheres.

[0060] (2) Preparation of the membrane electrode, the steps are as follows:

[0061] Take 300 mg of commercial 20 wt% Pt / C catalyst in a ball milling jar, add 5 g of zirconia ball milling beads of a certain size and 3 g of ultrapure water. Place the ball milling jar in a ball mill and ball mill for 20 minutes. After ball milling is completed, add 2.16 g of 5 wt% Nafion D520 solution as a binder and then transfer it to a mixed solvent of 4.885 g of ultrapure water and 23.655 g of isopropanol. The mixed solvent is ultrasonically dispersed at low temperature for 40 minutes to prepare a cathode catalyst slurry of 5 mg cat . / mL. The prepared slurry is sprayed on one side of the proton exchange membrane through an ultrasonic spraying device as the cathode catalyst layer, and the platinum loading is 0.3 mg / cm 2 .

[0062] Take 20 mg of the prepared porous amorphous iridium oxide microsphere catalyst in a ball milling jar, add 200 mg of large zirconia ball milling beads, 600 mg of small zirconia ball milling beads and 100 mg of ultrapure water. Place the ball milling jar in a ball mill and ball mill for 20 minutes. After completion, add 30 μL of 5 wt% Nafion D520 solution as a binder and then ball mill for 10 minutes. Finally, transfer it to a solvent with a volume ratio of isopropanol to ultrapure water of 3:1 of 4 mL. The mixed solvent is ultrasonically dispersed at low temperature for 40 minutes to prepare an anode catalyst slurry of 5 mg cat. / mL. The prepared slurry is sprayed on the other side of the proton exchange membrane through an ultrasonic spraying device as the anode catalyst layer, and the iridium loading is 0.5 mg / cm 2 .

[0063] The prepared membrane electrode is assembled into a PEM device for testing. Under the test conditions of 80 °C, the polarization curve of the electrolytic cell is obtained, and the results are shown inFigure 4 . Through Figure 4 it can be seen that at a current density of 3 A / cm 2 , the test voltage of the PEM device is 1.887 V.

[0064] The prepared membrane electrode was subjected to a stability test at 80 °C, and the results are shown in Figure 5 . Through Figure 5 it can be seen that when the membrane electrode operates at a current density of 1 A / cm 2 , the activity decay rate is negative; when it operates at a current density of 2 A / cm 2 , there is no obvious attenuation of the activity.

[0065] Example 2

[0066] (1) Synthesis of uniform porous amorphous iridium oxide microspheres, the steps are as follows:

[0067] First, cetyltrimethylammonium bromide and water were mixed evenly at a mass ratio of 3:1 and the pH of the solution was adjusted to 12. Chloroiridic acid was added to the mixed solution, and the mass ratio of chloroiridic acid to cetyltrimethylammonium bromide was 1:3. The mixed solution was heated in a constant-temperature oil bath under a nitrogen atmosphere protection, the heating temperature was 110 °C, and the heating time was 5 h. After the reaction ended, the obtained product was centrifuged and washed with deionized water and absolute ethanol, and then dried in a vacuum oven.

[0068] The centrifuged and dried product was fully ground and then impregnated in a nitric acid solution with a concentration of 0.3 mol / L. The mixed solution was transferred to a polytetrafluoroethylene reaction kettle and kept at 80 °C for 3 h. After the reaction system cooled to room temperature, the precipitate was obtained by centrifugal separation, and the target product - porous amorphous iridium oxide microspheres was obtained after washing and drying.

[0069] (2) Preparation of the membrane electrode, the steps are as follows:

[0070] Take 300 mg of commercial 20 wt% Pt / C catalyst in a ball mill jar, add 5 g of zirconia ball milling beads with a certain size and 3 g of ultrapure water. The ball mill jar was placed in a ball mill and ball milled for 20 minutes. After ball milling, 2.16 g of 5 wt% Nafion D520 solution was added as a binder and then it was transferred to a mixed solvent of 4.885 g of ultrapure water and 23.655 g of isopropanol. The mixed solvent was ultrasonically dispersed at low temperature for 40 minutes to prepare a cathode catalyst slurry of 5 mg cat . / mL. The prepared slurry was sprayed on one side of the proton exchange membrane through an ultrasonic spraying device as the cathode catalyst layer, and the platinum loading was 0.3 mg / cm 2 .

[0071] Take 20 mg of the prepared porous amorphous iridium oxide microsphere catalyst and place it in a ball mill jar. Add 200 mg of large zirconia ball milling beads, 600 mg of small zirconia ball milling beads, and 100 mg of ultrapure water to it. Place the ball mill jar in a ball mill and ball mill for 20 minutes. After completion, add 30 μL of 5 wt% Nafion D520 solution as a binder and then ball mill for 10 minutes. Finally, transfer it to a solvent with a volume ratio of isopropanol to ultrapure water of 3:1, and the volume is 4 mL. The mixed solvent is ultrasonically dispersed at low temperature for 40 minutes to prepare an anode catalyst slurry of 5 mg cat. / mL. The prepared slurry is sprayed on the other side of the proton exchange membrane through an ultrasonic spraying device as the anode catalytic layer, and the iridium loading is 0.5 mg / cm 2 .

[0072] Assemble the prepared membrane electrode into a PEM device for testing. Under the test conditions of 80 °C, obtain the polarization curve of the electrolytic cell, and the results are shown in Figure 4 . Through Figure 4 it can be seen that for this PEM device, at a current density of 3 A / cm 2 , the test voltage is 1.899 V.

[0073] Conduct a stability test on the prepared membrane electrode at 80 °C, and the results are shown in Figure 6 . Through Figure 6 it can be seen that when this membrane electrode operates at a current density of 1 A / cm 2 , the activity does not significantly decay; when it operates at a current density of 2 A / cm 2 , the performance decay rate is 16.1 μV / h.

[0074] Comparative Example 1

[0075] (1) Synthesis of amorphous iridium oxide nanoparticles, the steps are as follows:

[0076] First, mix 25 mg of iridium chloride acid and 20 mg of NaOH evenly in an aqueous solution, heat the mixed solution in an oil bath, the heating temperature is 90 °C, and the heating time is 10 h. After the reaction ends, centrifuge the obtained product, wash and centrifuge it with deionized water and absolute ethanol, and dry it in a vacuum oven to obtain amorphous iridium oxide nanoparticles.

[0077] Observe the above-prepared amorphous iridium oxide nanoparticles by TEM, and the results are as Figure 7 shown. Through Figure 7 it can be seen that the amorphous iridium oxide nanoparticles prepared by the method described in Comparative Example 1 do not exhibit a uniform and regular porous spherical morphology.

[0078] (2) Preparation of the membrane electrode, the steps are as follows:

[0079] Take 300 mg of commercial 20 wt% Pt / C catalyst in a ball milling jar, add 5 g of zirconia ball milling beads of a certain size and 3 g of ultrapure water. Place the ball milling jar in a ball mill and ball mill for 20 minutes. After ball milling is completed, add 2.16 g of 5 wt% Nafion D520 solution as a binder and then transfer it to a mixed solvent of 4.885 g of ultrapure water and 23.655 g of isopropanol. The mixed solvent is dispersed by low-temperature ultrasonic for 40 minutes to prepare a cathode catalyst slurry of 5 mg cat . / mL. The prepared slurry is sprayed on one side of the proton exchange membrane through an ultrasonic spraying device as the cathode catalyst layer, and the platinum loading is 0.3 mg / cm 2 .

[0080] Take 20 mg of the prepared amorphous iridium oxide nanoparticles as the comparison sample in a ball milling jar, add 200 mg of large zirconia ball milling beads, 600 mg of small zirconia ball milling beads and 100 mg of ultrapure water to it. Place the ball milling jar in a ball mill and ball mill for 20 minutes. After completion, add 30 μL of 5 wt% Nafion D520 solution as a binder and then ball mill for another 10 minutes. Finally, transfer it to a solvent with a volume ratio of isopropanol to ultrapure water of 3:1 of 4 mL. The mixed solvent is dispersed by low-temperature ultrasonic for 40 minutes to prepare an anode catalyst slurry of 5 mg cat. / mL. The prepared slurry is sprayed on the other side of the proton exchange membrane through an ultrasonic spraying device as the anode catalyst layer, and the iridium loading is 0.5 mg / cm 2 .

[0081] Assemble the prepared membrane electrode into a PEM device for testing. Under the test conditions of 80 °C, the polarization curve of the electrolytic cell is obtained, and the results are shown in Figure 4 . Through Figure 4 it can be seen that the PEM device has a test voltage of 1.922 V at a current density of 3 A / cm 2 .

[0082] Conduct a stability test on the prepared membrane electrode at 80 °C, and the results are shown in Figure 8 . Through Figure 8 it can be seen that when the membrane electrode operates at a current density of 1 A / cm 2 , an obvious attenuation of activity can be observed, and the performance attenuation rate reaches 77.1 μV / h.

[0083] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing porous amorphous iridium oxide microspheres, characterized in that, It includes the following steps: a) Mix an iridium source compound with an aqueous solution of cetyltrimethylammonium bromide with a basic pH value, and heat and react under anaerobic conditions to obtain a solid product; b) Mix the solid product with an acid solution and perform heat treatment to obtain porous amorphous iridium oxide microspheres.

2. The preparation method according to claim 1, characterized in that, In step a), the iridium source compound is one or more of chloroiridic acid, iridium trichloride, iridium acetylacetonate, iridium acetate, and potassium chloroiridate.

3. The preparation method according to claim 1, characterized in that, In step a), the mass ratio of cetyltrimethylammonium bromide to water in the aqueous solution of cetyltrimethylammonium bromide is (3 - 5):1; the pH value of the aqueous solution of cetyltrimethylammonium bromide is 10 - 13.

4. The preparation method according to claim 1, wherein, In step a), the mass ratio of the iridium source compound to cetyltrimethylammonium bromide in the aqueous solution of cetyltrimethylammonium bromide is 1:(3 - 5).

5. The preparation method according to claim 1, characterized in that, In step a), the temperature of the heating reaction is 90 - 120 °C, and the time is 5 - 8 h.

6. The preparation method according to claim 1, wherein In step b), before mixing with the acid solution, the solid product is first ground.

7. The preparation method according to claim 1, characterized in that, In step b), the acid in the acid solution is one or more of sulfuric acid, nitric acid, and hydrochloric acid; the acid concentration of the acid solution is 0.1 - 1 mol / L.

8. The preparation method according to claim 1, wherein, In step b), the temperature of the heat treatment is 60 - 90 °C, and the time is 1 - 4 h.

9. A porous amorphous iridium oxide microsphere, characterized in that, Prepared according to the preparation method described in any one of claims 1 - 8.

10. A method for producing hydrogen by proton exchange membrane electrolysis of water, characterized in that, It includes the following steps: Use a membrane electrode to electrolyze water to produce hydrogen; The membrane electrode includes a proton exchange membrane, a cathode catalytic layer compounded on one surface of the proton exchange membrane, and an anode catalytic layer compounded on the other surface of the proton exchange membrane; the composition of the anode catalytic layer includes the porous amorphous iridium oxide microspheres described in claim 9.

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