Electrolysis water catalyst with compact coating shell structure and preparation method and application thereof

Abstract

The present application relates to a kind of water electrolysis catalyst with dense cladding shell structure and its preparation method and application, belong to catalytic preparation technical field.The preparation method of the present application includes the following steps: dense cladding iridium / ruthenium metal shell layer is formed on the surface of metal titanium powder using ethylene glycol reflux method;2) centrifugal separation in organic solvent, vacuum freeze-drying, sample is collected under the condition of inert atmosphere protection, to protect the metal shell structure.The catalyst obtained by the preparation method provided by the present application has dense cladding metal shell layer, which can form a good electron conduction channel, overcome the problem of insufficient conductivity of the stable non-noble carrier itself under the environment of proton exchange membrane water electrolysis oxygen analysis, reduce the amount of noble metal, effectively improve the catalytic activity expression of proton exchange membrane water electrolysis oxygen analysis catalyst.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of catalyst preparation, in particular to an electrolytic water catalyst with a dense coating shell structure and a preparation method and application thereof. BACKGROUND

[0002] Hydrogen has high energy density and clean characteristics, and has become a promising alternative to fossil fuels. Compared with the hydrogen production by natural gas reforming under complex conditions, the water electrolysis hydrogen production technology uses renewable energy (such as solar energy and wind energy) and operates under mild conditions, and is a clean and more promising method to obtain high-purity hydrogen (LI L, WANG P, SHAO Q, et al. Recent Progress in Advanced Electrocatalyst Design for Acidic Oxygen Evolution Reaction [J]. Adv Mater, 2021: e2004243). Compared with alkaline water electrolysis and solid oxide water electrolysis, the water electrolysis technology using proton exchange membrane has the advantages of compact system, low gas cross, high efficiency, fast response speed, high current density, etc., and becomes a hydrogen production method with great application prospect (JIN H, JOO J, CHAUDHARI N K, et al. Recent Progress in Bifunctional Electrocatalysts for Overall Water Splitting under Acidic Conditions [J]. ChemElectroChem, 2019, 6 (13): 3244-53.). However, the anode side of the proton exchange membrane water electrolysis has a local strong acid environment (generally with pH = 1 as the standard) and a high potential oxidation environment (oxygen evolution onset potential > 1.23), which leads to only a few elements: Ti, Zr, Hf, Nb, Ta, Sn, Si, Pt, Ru, Ir, Au, Rh, Pd, W have a relatively wide non-dissolution area in the E-pH phase diagram (POURBAIX M. Atlas of Electrochemical Equilibria in Aqueous Solution [J]. NACE, 1974, 307.), among which only Ir and Ru have sufficient oxygen evolution activity and are used as active substances in the oxygen evolution catalyst on the anode side. As for Ti, Zr, Hf, Nb, Ta, Sn, Si and W, these non-noble metals are generally not considered to have oxygen evolution activity, and they are used as active substance dispersing carriers or dopants in the oxygen evolution catalyst to regulate the activity or stability of the active substance.

[0003] Titanium element, as an element with multiple valence (0, +2, +3, +4) and relatively low resistivity, has obvious advantages in regulating the oxygen vacancy content of the catalyst and the electronic structure of the active substance, so it is widely studied in the field of proton exchange membrane oxygen evolution catalysts. However, titanium element series materials, even metal titanium powder (the surface of metal titanium powder will undergo self-oxidation process in air or aqueous environment, producing an oxidation thin layer with poor conductivity) (SHVAB R, HRYHAE, NYBORG L. Surface chemistry of the titanium powder studied by XPS using internal standard reference [J]. Powder Metallurgy, 2017, 60(1): 42-8.), its conductivity in actual use is still much lower than that of conductive iridium / ruthenium metal and its oxide.

[0004] In order to reduce the amount of noble metal in the oxygen evolution catalyst to reduce the cost, while ensuring that the catalyst has sufficient conductivity to promote the effective expression of the catalytic activity of the active substance, preparing an oxygen evolution catalyst with a core-shell structure (the conductive active substance is the shell, and the non-noble substance is the core) is a relatively ideal design scheme (TACKETT B M, SHENG W, KATTEL S, et al. Reducing Iridium Loading in Oxygen Evolution Reaction Electrocatalysts Using Core-Shell Particles with Nitride Cores [J]. ACS Catalysis, 2018, 8 (3): 2615-21.). However, the active substance loaded on the non-noble carrier often has the characteristics of uneven dispersion (KARIMI F, PEPPLEY B A. Metal Carbide and Oxide Supports for Iridium-Based Oxygen Evolution Reaction Electrocatalysts for Polymer-Electrolyte-Membrane Water Electrolysis [J]. Electrochimica Acta, 2017, 246: 654-70.), which will cause the catalyst to use a high proportion of noble metal to ensure conductivity. For example, the known commercial Umicore IrO2-TiO2 contains 75wt.% of iridium element. Therefore, developing an oxygen evolution catalyst related technology that can form a dense coated core-shell structure is of great significance to reduce the use cost of the oxygen evolution catalyst in water electrolysis technology. SUMMARY

[0005] Therefore, the present application aims to solve the technical problems in the prior art and provides an electrolytic water catalyst with a dense coated shell structure and a preparation method and application thereof. The catalyst prepared by the preparation method of the present application has the characteristics of a dense coated metal shell structure, effectively improving the conductivity of the catalyst and reducing the amount of noble metal used.

[0006] In order to solve the above technical problems, the technical scheme of the present application is as follows:

[0007] The present application provides a preparation method of an electrolytic water catalyst with a dense coated shell structure, comprising the following steps:

[0008] A) adding metal titanium powder and a surfactant into ethylene glycol and ultrasonically dispersing to obtain a uniformly dispersed turbid liquid A;

[0009] B) stirring the turbid liquid A, and adding the iridium precursor or the ruthenium precursor into the turbid liquid A under stirring, continuing to stir the turbid liquid A to make the precursor uniformly dispersed to obtain turbid liquid B;

[0010] C) performing ethylene glycol reflux reduction reaction on the turbid liquid B under inert gas protection condition and stirring condition, naturally cooling after the reaction is completed, and finally obtaining turbid liquid C;

[0011] D) centrifuging the turbid liquid C, and performing centrifugal washing with an organic solvent for at least three times, vacuum freeze-drying the precipitate obtained by centrifugal washing, and collecting the catalyst sample under inert atmosphere protection condition after the drying is completed.

[0012] In the technical scheme, preferably, the thickness of the catalyst-coated metal shell is 5-20 nm, and the coated metal loading is 20-70 wt.%.

[0013] In the technical scheme, preferably, the surfactant is cetyltrimethylammonium bromide or polyvinylpyrrolidone or sodium dodecyl sulfate.

[0014] In the technical scheme, preferably, the mass-volume ratio of the titanium metal powder to ethylene glycol is 0.1 mg:1 mL-2 mg:1 mL, and the molar ratio of the surfactant to the iridium or ruthenium element in the precursor is 0.1 mol:1 mol-10 mol:1 mol.

[0015] In the technical scheme, preferably, the iridium precursor is chloroiridic acid, potassium chloroiridate, iridium trichloride, iridium acetate or acetylacetone iridium, the ruthenium precursor is ruthenium trichloride, ruthenium acetate, potassium chlororuthenate, chlororuthenic acid or acetylacetone ruthenium, and the inert protective gas during the ethylene glycol reflux reduction reaction is nitrogen or argon.

[0016] In the technical scheme, preferably, the ultrasonic dispersion time is 0.5-5 h, the stirring time after the iridium precursor or the ruthenium precursor is added is 0.5-5 h, the ethylene glycol reflux reduction reaction temperature is 140-200 ℃, the ethylene glycol reflux reduction reaction time is 1-5 h, and the centrifugal separation operating condition is a rotation speed of 10,000-15,000 rpm and a time of 3-5 min.

[0017] In the technical scheme, preferably, the organic solvent used in the centrifugal washing process is ethanol or isopropyl alcohol or trichloromethane or acetone.

[0018] In the technical scheme, preferably, the vacuum freeze-drying time is 8-24 h, and the inert protective atmosphere used for sampling after the drying is completed is nitrogen or argon.

[0019] The application further provides an electrolytic water catalyst with a dense coated shell structure prepared by the preparation method.

[0020] The application also provides application of the electrolytic water catalyst with the dense cladding shell structure as a proton exchange membrane water electrolysis oxygen evolution catalyst in hydrogen production by water electrolysis.

[0021] The application has the following beneficial effects:

[0022] The application provides a preparation method of an electrolytic water catalyst with a dense cladding shell structure.

[0023] The catalyst prepared by the preparation method has a dense cladding metal shell layer, the dense cladding metal shell layer can form a good electron conduction channel, overcome the problem of insufficient conductivity of the stable non-noble carrier itself in the proton exchange membrane water electrolysis oxygen environment, and further effectively improve the catalytic activity expression of the proton exchange membrane water electrolysis oxygen catalyst. BRIEF DESCRIPTION OF DRAWINGS

[0024] The application will be further described in detail below in combination with the drawings and specific embodiments.

[0025] Figure 1 The contrastive drawing (20nm scale) of the electron microscope pictures of the iridium metal shell catalyst (50wt.% iridium loading) with the dense cladding shell structure prepared in Example 1 of the application, the ruthenium metal shell catalyst (50wt.% ruthenium loading) with the dense cladding shell structure prepared in Example 2 of the application, and the electron microscope picture of the metal titanium powder used in the application.

[0026] Figure 2 The electron microscope picture of the iridium metal shell catalyst (50wt.% iridium loading, 100nm scale) with the dense cladding shell structure prepared in Example 1 of the application.

[0027] Figure 3 The electron microscope picture of the ruthenium metal shell catalyst (50wt.% ruthenium loading, 100nm scale) with the dense cladding shell structure prepared in Example 2 of the application.

[0028] Figure 4 The four-probe powder conductivity contrastive drawing of the iridium metal shell catalyst (50wt.% iridium loading) with the dense cladding shell structure prepared in Example 1 of the application, the metal titanium powder, and the grinding mixture of the metal titanium powder and the ethylene glycol refluxed iridium metal (the mass ratio of the metal titanium powder to the ethylene glycol refluxed iridium metal is 1:1).

[0029] Figure 5This is a comparison chart of the catalytic activities of the iridium metal shell catalyst (20 wt.% iridium loading) with a dense coating shell structure prepared in Example 3 of the present invention and the commercial TiO2 powder loaded with iridium metal (20 wt.% iridium loading) by the ethylene glycol reflux method tested in 0.5 mol / L sulfuric acid solution.

[0030] Figure 6 This is a comparison chart of the mass specific activities of the iridium metal shell catalyst (50 wt.% iridium loading) with a dense coating shell structure prepared in Example 1 of the present invention and the ethylene glycol refluxed iridium metal tested in 0.5 mol / L sulfuric acid solution.

[0031] Figure 7 The constant current (10 mA cm) obtained by testing the iridium metal shell catalyst (50 wt.% iridium loading) with a dense coating shell structure prepared in Example 1 of the present invention and the commercial iridium catalyst in 0.5 mol / L sulfuric acid solution was -2 )Stability comparison chart. DETAILED DESCRIPTION

[0032] In order to further understand the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with the embodiments. The protection scope of the present invention is not limited by the following embodiments.

[0033] Example 1

[0034] 25 mg of metallic titanium powder and 144 mg of hexadecyltrimethylammonium bromide were added to 80 mL of ethylene glycol and ultrasonically dispersed for 1 hour to obtain a uniformly dispersed turbid liquid A; the turbid liquid A was stirred, and 25 mg of iridium chloroiridic acid was added to the turbid liquid A under stirring, and the turbid liquid A was continued to be stirred for 2 hours to uniformly disperse the iridium precursor to obtain a turbid liquid B; the turbid liquid B was subjected to a 160°C ethylene glycol reflux reduction reaction for 3 hours under nitrogen gas protection conditions and stirring conditions, and the reaction was naturally cooled after the reaction was completed to finally obtain a turbid liquid C; the turbid liquid C was centrifuged at 12000 rpm for 3 minutes, and centrifuged and washed three times with anhydrous ethanol. The precipitate obtained by centrifugal washing was vacuum freeze-dried for 8 hours. After drying, the catalyst sample was collected under nitrogen atmosphere protection conditions.

[0035] Comparative sample: Preparation of iridium metal by ethylene glycol reflux without a carrier. Except for not adding the metal titanium powder carrier, other preparation conditions are consistent with the above-mentioned relevant preparation conditions.

[0036] Comparative sample: Preparation method of a ground mixture of metallic titanium powder and unsupported ethylene glycol refluxed iridium metal (the mass ratio of metallic titanium powder: ethylene glycol refluxed iridium metal is 1:1): Take 30 mg of unsupported ethylene glycol refluxed iridium metal and 30 mg of metallic titanium powder, grind them in an agate mortar for at least 30 minutes until the color of the mixed sample is uniform, and then scrape and collect the sample.

[0037] The iridium metal shell catalyst with dense coating shell structure prepared in Example 1 was characterized by electron microscopy. The results are shown in the attached Figure 1 and 2 As shown, iridium metal forms a dense shell on the surface of the titanium powder carrier. Based on the observation of the shell thickness in the morphological characterization image, the thickness of the iridium shell on titanium powder particles of different particle sizes varies, and the thickness of the iridium shell is roughly 5 to 20nm.

[0038] The iridium metal shell catalyst with a dense coating shell structure prepared in Example 1 was characterized by a four-probe powder conductivity test. The results are shown in the attached Figure 4 As shown in the figure, the conductivity of the catalyst with 50 wt.% iridium loading is much higher than that of the mechanical mixture of titanium powder and unsupported ethylene glycol refluxed iridium metal (mass ratio of titanium powder to iridium metal is 1:1).

[0039] The iridium metal shell catalyst with a dense coating shell structure prepared in Example 1 was characterized for catalytic activity in a 0.5 mol / L sulfuric acid solution. The results are shown in the attached Figure 6 As shown in the figure, the mass specific activity of the catalyst with 50 wt.% iridium loading is higher than the mass specific activity of ethylene glycol refluxed iridium metal.

[0040] The iridium metal shell catalyst with a dense coating shell structure prepared in Example 1 was characterized for catalytic stability in a 0.5 mol / L sulfuric acid solution. The results are shown in the attached Figure 7 As shown in the results, the stability of the prepared catalyst with 50 wt.% iridium loading is better than that of the commercial IrO2 catalyst.

[0041] Example 2

[0042] 25 mg of metallic titanium powder and 144 mg of hexadecyltrimethylammonium bromide were added to 80 mL of ethylene glycol and ultrasonically dispersed for 1 hour to obtain a uniformly dispersed turbid liquid A; the turbid liquid A was stirred, and 25 mg of ruthenium trichloride was added to the turbid liquid A under stirring, and the turbid liquid A was continued to be stirred for 2 hours to uniformly disperse the ruthenium precursor to obtain a turbid liquid B; the turbid liquid B was subjected to a 160°C ethylene glycol reflux reduction reaction under nitrogen gas protection conditions and stirring conditions for 3 hours, and the reaction was completed and naturally cooled to finally obtain a turbid liquid C; the turbid liquid C was centrifuged at 12000 rpm for 3 minutes, and centrifuged and washed three times with anhydrous ethanol. The precipitate obtained by centrifugal washing was vacuum freeze-dried for 8 hours. After drying, the catalyst sample was collected under nitrogen atmosphere protection conditions.

[0043] The ruthenium metal shell catalyst with dense coating shell structure prepared in Example 2 was characterized by electron microscopy. The results are shown in the attached Figure 1 and 3As shown, the ruthenium metal forms a dense coated shell layer on the surface of the metal titanium powder carrier. Based on the observation of the shell layer thickness in the morphology characterization picture, the ruthenium shell layer thickness on the metal titanium powder particles of different particle sizes is different, and the thickness of the ruthenium shell layer is about 5-20 nm.

[0044] The ruthenium metal shell catalyst with a dense coated shell structure prepared in Example 2 was subjected to four-probe powder conductivity characterization, catalytic activity characterization, and catalytic stability characterization, and the characterization results were similar to the related characterization results of Example 1.

[0045] Example 3

[0046] 40 mg of metal titanium powder and 57 mg of cetyltrimethylammonium bromide were added to 80 mL of ethylene glycol and ultrasonically dispersed for 1 h to obtain a uniformly dispersed turbid liquid A; the turbid liquid A was stirred, and 10 mg of iridium element-containing chloroiridic acid was added to the turbid liquid A under stirring to uniformly disperse the iridium precursor to obtain a turbid liquid B; the turbid liquid B was subjected to a 160°C ethylene glycol reflux reduction reaction under nitrogen gas protection and stirring conditions for 3 h, and after the reaction was completed, it was naturally cooled to obtain a turbid liquid C; the turbid liquid C was centrifuged at 12000 rpm for 3 min, and washed with anhydrous ethanol three times, and the precipitate obtained by centrifugal washing was vacuum freeze-dried for 8 h, and the catalyst sample was collected under nitrogen atmosphere protection after the drying was completed.

[0047] Comparative sample: preparation method of commercial TiO2 powder loaded with iridium metal (20 wt.% iridium loading) by ethylene glycol reflux method: 40 mg of commercial TiO2 powder and 57 mg of cetyltrimethylammonium bromide were added to 80 mL of ethylene glycol and ultrasonically dispersed for 1 h to obtain a uniformly dispersed turbid liquid A; the turbid liquid A was stirred, and 10 mg of iridium element-containing chloroiridic acid was added to the turbid liquid A under stirring to uniformly disperse the iridium precursor to obtain a turbid liquid B; the turbid liquid B was subjected to a 160°C ethylene glycol reflux reduction reaction under nitrogen gas protection and stirring conditions for 3 h, and after the reaction was completed, it was naturally cooled to obtain a turbid liquid C; the turbid liquid C was centrifuged at 12000 rpm for 3 min, and washed with anhydrous ethanol three times, and the precipitate obtained by centrifugal washing was vacuum freeze-dried for 8 h, and the catalyst sample was collected under nitrogen atmosphere protection after the drying was completed.

[0048] The iridium metal shell catalyst with a dense coated shell structure prepared in Example 3 was subjected to catalytic activity characterization, and the results are shown in the following table. Figure 5 As shown, the catalytic activity of the prepared 20 wt.% iridium loading catalyst is significantly higher than that of the commercial TiO2 powder loaded with iridium metal (20 wt.% iridium loading) by ethylene glycol reflux method.

[0049] The iridium metal shell catalyst with dense coating shell structure prepared in Example 3 is subjected to electron microscope morphology characterization, four-probe method powder conductivity characterization, and catalytic stability characterization, and the characterization results are similar to the related characterization results of Example 1.

[0050] Example 4

[0051] 35 mg of metal titanium powder and 8.6 g of polyvinylpyrrolidone (average molecular weight 8000) are added to 80 mL of ethylene glycol and ultrasonically dispersed for 0.5 h to obtain a uniformly dispersed turbid liquid A; the turbid liquid A is stirred, and 15 mg of potassium chloroiridate containing iridium element is added to the turbid liquid A under stirring, and the turbid liquid A is continuously stirred for 5 h to uniformly disperse the iridium precursor to obtain a turbid liquid B; the turbid liquid B is subjected to 160℃ ethylene glycol reflux reduction reaction under the condition of nitrogen gas protection and stirring for 5 h, and after the reaction is completed, it is naturally cooled, finally obtaining a turbid liquid C; the turbid liquid C is subjected to centrifugal separation at 15000 rpm for 5 min, and is washed with trichloromethane for three times, and the precipitate obtained by centrifugal washing is vacuum freeze-dried for 8 h, and the catalyst sample is collected under the protection of nitrogen atmosphere after the drying is completed.

[0052] The iridium metal shell catalyst with dense coating shell structure prepared in Example 4 is subjected to electron microscope morphology characterization, catalytic activity characterization, four-probe method powder conductivity characterization, and catalytic stability characterization, and the characterization results are similar to the related characterization results of Example 1.

[0053] Example 5

[0054] 30 mg of metal titanium powder and 115 mg of sodium dodecyl sulfate are added to 80 mL of ethylene glycol and ultrasonically dispersed for 5 h to obtain a uniformly dispersed turbid liquid A; the turbid liquid A is stirred, and 20 mg of iridium trichloride containing iridium element is added to the turbid liquid A under stirring, and the turbid liquid A is continuously stirred for 2 h to uniformly disperse the iridium precursor to obtain a turbid liquid B; the turbid liquid B is subjected to 200℃ ethylene glycol reflux reduction reaction under the condition of nitrogen gas protection and stirring for 3 h, and after the reaction is completed, it is naturally cooled, finally obtaining a turbid liquid C; the turbid liquid C is subjected to centrifugal separation at 10000 rpm for 3 min, and is washed with isopropyl alcohol for three times, and the precipitate obtained by centrifugal washing is vacuum freeze-dried for 24 h, and the catalyst sample is collected under the protection of nitrogen atmosphere after the drying is completed.

[0055] The iridium metal shell catalyst with dense coating shell structure prepared in Example 5 is subjected to electron microscope morphology characterization, catalytic activity characterization, four-probe method powder conductivity characterization, and catalytic stability characterization, and the characterization results are similar to the related characterization results of Example 1.

[0056] Example 6

[0057] Put 20 mg of metal titanium powder and 172 mg of cetyl trimethyl ammonium bromide into 80 mL of ethylene glycol and ultrasonic dispersion for 2 h to obtain a uniformly dispersed turbidity A; the turbidity A is stirred, and 30 mg of iridium acetate containing iridium element is added to the turbidity A under stirring, and the turbidity A is continuously stirred for 0.5 h to make the iridium precursor uniformly dispersed to obtain turbidity B; the turbidity B is subjected to 140℃ ethylene glycol reflux reduction reaction under the condition of argon gas protection and stirring for 1 h, and the reaction is naturally cooled after completion; finally, the turbidity C is obtained; the turbidity C is centrifuged at 12000 rpm for 3 min, washed with acetone for three times, and the precipitate obtained by centrifugal washing is vacuum freeze-dried for 8 h, and the catalyst sample is collected under the protection of argon atmosphere.

[0058] The iridium metal shell catalyst with dense coating shell structure prepared in Example 6 is subjected to electron microscope morphology characterization, catalytic activity characterization, four-probe method powder conductivity characterization, and catalytic stability characterization, and the characterization results are similar to the related characterization results of Example 1.

[0059] Example 7

[0060] Put 15 mg of metal titanium powder and 201 mg of cetyl trimethyl ammonium bromide into 80 mL of ethylene glycol and ultrasonic dispersion for 1 h to obtain a uniformly dispersed turbidity A; the turbidity A is stirred, and 35 mg of acetylacetone iridium containing iridium element is added to the turbidity A under stirring, and the turbidity A is continuously stirred for 2 h to make the iridium precursor uniformly dispersed to obtain turbidity B; the turbidity B is subjected to 160℃ ethylene glycol reflux reduction reaction under the condition of nitrogen gas protection and stirring for 3 h, and the reaction is naturally cooled after completion; finally, the turbidity C is obtained; the turbidity C is centrifuged at 12000 rpm for 3 min, washed with anhydrous ethanol for three times, and the precipitate obtained by centrifugal washing is vacuum freeze-dried for 8 h, and the catalyst sample is collected under the protection of nitrogen atmosphere.

[0061] The iridium metal shell catalyst with dense coating shell structure prepared in Example 7 is subjected to electron microscope morphology characterization, catalytic activity characterization, four-probe method powder conductivity characterization, and catalytic stability characterization, and the characterization results are similar to the related characterization results of Example 1.

[0062] Example 8

[0063] Put 40 mg of metal titanium powder and 57 mg of cetyl trimethyl ammonium bromide into 80 mL of ethylene glycol and ultrasonic dispersion for 1 h to obtain a uniformly dispersed turbidity A; the turbidity A is stirred, and 10 mg of ruthenium acetate containing an amount of ruthenium element is added to the turbidity A under stirring, and the turbidity A is continuously stirred for 2 h to make the ruthenium precursor uniformly dispersed to obtain turbidity B; the turbidity B is subjected to 160℃ ethylene glycol reflux reduction reaction under the condition of nitrogen gas protection and stirring for 3 h, and the reaction is naturally cooled after completion, and finally the turbidity C is obtained; the turbidity C is centrifuged at 12000 rpm for 3 min, washed with anhydrous ethanol for three times, and the precipitate obtained by centrifugal washing is vacuum freeze-dried for 8 h, and the catalyst sample is collected under the protection of nitrogen atmosphere.

[0064] The ruthenium metal shell catalyst with dense coating shell structure prepared in Example 8 is subjected to electron microscope morphology characterization, catalytic activity characterization, four-probe method powder conductivity characterization, and catalytic stability characterization, and the characterization results are similar to the related characterization results of Example 1.

[0065] Example 9

[0066] Put 35 mg of metal titanium powder and 8.6 g of polyvinylpyrrolidone (average molecular weight 8000) into 80 mL of ethylene glycol and ultrasonic dispersion for 0.5 h to obtain a uniformly dispersed turbidity A; the turbidity A is stirred, and 15 mg of potassium chlororuthenate containing an amount of ruthenium element is added to the turbidity A under stirring, and the turbidity A is continuously stirred for 5 h to make the ruthenium precursor uniformly dispersed to obtain turbidity B; the turbidity B is subjected to 160℃ ethylene glycol reflux reduction reaction under the condition of nitrogen gas protection and stirring for 5 h, and the reaction is naturally cooled after completion, and finally the turbidity C is obtained; the turbidity C is centrifuged at 15000 rpm for 5 min, washed with trichloromethane for three times, and the precipitate obtained by centrifugal washing is vacuum freeze-dried for 8 h, and the catalyst sample is collected under the protection of nitrogen atmosphere.

[0067] The ruthenium metal shell catalyst with dense coating shell structure prepared in Example 9 is subjected to electron microscope morphology characterization, catalytic activity characterization, four-probe method powder conductivity characterization, and catalytic stability characterization, and the characterization results are similar to the related characterization results of Example 1.

[0068] Example 10

[0069] Put 30 mg of metal titanium powder and 115 mg of sodium dodecyl sulfate into 80 mL of ethylene glycol and ultrasonic dispersion for 5 h to obtain a uniformly dispersed turbidity A; the turbidity A is stirred, and 20 mg of ruthenium element-containing chlororuthenic acid is added to the turbidity A under stirring, and the turbidity A is continuously stirred for 2 h to uniformly disperse the ruthenium precursor to obtain turbidity B; the turbidity B is subjected to 200℃ ethylene glycol reflux reduction reaction under the condition of nitrogen gas protection and stirring for 3 h, and the reaction is naturally cooled after completion; finally, turbidity C is obtained; the turbidity C is centrifuged at 10000 rpm for 3 min, washed with isopropyl alcohol for three times, and the precipitate obtained by centrifugal washing is vacuum freeze-dried for 24 h; and the catalyst sample is collected under the protection of nitrogen atmosphere after drying.

[0070] The ruthenium metal shell catalyst with a dense coating shell structure prepared in Example 10 is subjected to electron microscope morphology characterization, catalytic activity characterization, four-probe method powder conductivity characterization, and catalytic stability characterization, and the characterization results are similar to the related characterization results of Example 1.

[0071] Example 11

[0072] Put 20 mg of metal titanium powder and 172 mg of cetyltrimethylammonium bromide into 80 mL of ethylene glycol and ultrasonic dispersion for 2 h to obtain a uniformly dispersed turbidity A; the turbidity A is stirred, and 30 mg of ruthenium element-containing acetylacetone ruthenium is added to the turbidity A under stirring, and the turbidity A is continuously stirred for 0.5 h to uniformly disperse the ruthenium precursor to obtain turbidity B; the turbidity B is subjected to 140℃ ethylene glycol reflux reduction reaction under the condition of argon gas protection and stirring for 1 h, and the reaction is naturally cooled after completion; finally, turbidity C is obtained; the turbidity C is centrifuged at 12000 rpm for 3 min, washed with acetone for three times, and the precipitate obtained by centrifugal washing is vacuum freeze-dried for 8 h; and the catalyst sample is collected under the protection of argon atmosphere after drying.

[0073] The ruthenium metal shell catalyst with a dense coating shell structure prepared in Example 11 is subjected to electron microscope morphology characterization, catalytic activity characterization, four-probe method powder conductivity characterization, and catalytic stability characterization, and the characterization results are similar to the related characterization results of Example 1.

[0074] Example 12

[0075] Put 15 mg of metal titanium powder and 201 mg of cetyl trimethyl ammonium bromide into 80 mL of ethylene glycol and ultrasonic dispersion for 1 h to obtain a uniformly dispersed turbidity A; the turbidity A is stirred, and 35 mg of ruthenium trichloride containing an amount of ruthenium element is added to the turbidity A under stirring, and the turbidity A is continuously stirred for 2 h to make the ruthenium precursor uniformly dispersed to obtain turbidity B; the turbidity B is subjected to 160℃ ethylene glycol reflux reduction reaction under the condition of nitrogen gas protection and stirring for 3 h, and the reaction is naturally cooled after completion, and finally the turbidity C is obtained; the turbidity C is centrifuged at 12000 rpm for 3 min, washed with anhydrous ethanol for three times, and the precipitate obtained by centrifugal washing is vacuum freeze-dried for 8 h, and the catalyst sample is collected under the protection of nitrogen atmosphere.

[0076] The ruthenium metal shell catalyst with dense coating shell structure prepared in Example 12 is subjected to electron microscope morphology characterization, catalytic activity characterization, four-probe method powder conductivity characterization, and catalytic stability characterization, and the characterization results are similar to the related characterization results of Example 1.

[0077] Example 13

[0078] Put 25 mg of metal titanium powder and 144 mg of cetyl trimethyl ammonium bromide into 250 mL of ethylene glycol and ultrasonic dispersion for 1 h to obtain a uniformly dispersed turbidity A; the turbidity A is stirred, and 25 mg of iridium chloroacid containing an amount of iridium element is added to the turbidity A under stirring, and the turbidity A is continuously stirred for 2 h to make the iridium precursor uniformly dispersed to obtain turbidity B; the turbidity B is subjected to 160℃ ethylene glycol reflux reduction reaction under the condition of nitrogen gas protection and stirring for 3 h, and the reaction is naturally cooled after completion, and finally the turbidity C is obtained; the turbidity C is centrifuged at 12000 rpm for 3 min, washed with anhydrous ethanol for three times, and the precipitate obtained by centrifugal washing is vacuum freeze-dried for 8 h, and the catalyst sample is collected under the protection of nitrogen atmosphere.

[0079] The iridium metal shell catalyst with dense coating shell structure prepared in Example 13 is subjected to electron microscope morphology characterization, catalytic activity characterization, four-probe method powder conductivity characterization, and catalytic stability characterization, and the characterization results are similar to the related characterization results of Example 1.

[0080] Example 14

[0081] 30mg of metal titanium powder and 4mg of sodium dodecyl sulfate were added into 15mL of ethylene glycol and ultrasonically dispersed for 5h to obtain a uniformly dispersed turbid liquid A; the turbid liquid A was stirred, and 20mg of iridium chloride containing an iridium element was added to the turbid liquid A under stirring, and the turbid liquid A was continuously stirred for 5h to uniformly disperse the iridium precursor to obtain a turbid liquid B; the turbid liquid B was subjected to a 200℃ ethylene glycol reflux reduction reaction under the condition of nitrogen gas protection and stirring for 3h, and was naturally cooled after the reaction was completed; finally, a turbid liquid C was obtained; the turbid liquid C was centrifuged at 10000rpm for 3min, and was washed with isopropyl alcohol for three times; the precipitate obtained by centrifugal washing was vacuum freeze-dried for 8h, and the catalyst sample was collected under the condition of nitrogen atmosphere protection after the drying was completed.

[0082] The iridium metal shell catalyst with the dense coating shell structure prepared in Example 14 was subjected to electron microscope morphology characterization, catalytic activity characterization, four-probe method powder conductivity characterization, and catalytic stability characterization, and the characterization results were similar to the related characterization results of Example 1.

[0083] Example 15

[0084] 20mg of metal titanium powder and 568mg of cetyltrimethylammonium bromide were added into 200mL of ethylene glycol and ultrasonically dispersed for 2h to obtain a uniformly dispersed turbid liquid A; the turbid liquid A was stirred, and 30mg of iridium acetate containing an iridium element was added to the turbid liquid A under stirring, and the turbid liquid A was continuously stirred for 0.5h to uniformly disperse the iridium precursor to obtain a turbid liquid B; the turbid liquid B was subjected to a 140℃ ethylene glycol reflux reduction reaction under the condition of argon gas protection and stirring for 1h, and was naturally cooled after the reaction was completed; finally, a turbid liquid C was obtained; the turbid liquid C was centrifuged at 12000rpm for 3min, and was washed with acetone for three times; the precipitate obtained by centrifugal washing was vacuum freeze-dried for 8h, and the catalyst sample was collected under the condition of argon atmosphere protection after the drying was completed.

[0085] The iridium metal shell catalyst with the dense coating shell structure prepared in Example 15 was subjected to electron microscope morphology characterization, catalytic activity characterization, four-probe method powder conductivity characterization, and catalytic stability characterization, and the characterization results were similar to the related characterization results of Example 1.

[0086] The above description of the examples is only used to help understand the method of the present application and its core idea. It should be noted that those skilled in the art can make several improvements and modifications to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

[0087] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Modifications of these embodiments will occur to persons of skill in the art, and that the appended claims are intended to cover all such modifications that do not depart from the true spirit and scope of the application. Therefore, the application is not limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for producing an electrolytic water catalyst having a dense coating shell structure, characterized by, The method comprises the following steps: A) adding metal titanium powder and a surfactant into ethylene glycol and ultrasonic dispersing to obtain a uniformly dispersed turbid liquid A; B) stirring the turbid liquid A and adding an iridium precursor or a ruthenium precursor into the turbid liquid A under stirring, continuing to stir the turbid liquid A to uniformly disperse the precursor to obtain a turbid liquid B; C) performing ethylene glycol reflux reduction reaction on the turbid liquid B under inert gas protection and stirring, naturally cooling after the reaction is completed, and finally obtaining a turbid liquid C; D) centrifuging the turbid liquid C and washing the obtained precipitate by centrifugation with an organic solvent for at least three times, vacuum freeze-drying the precipitate obtained by centrifugal washing, and collecting the catalyst sample under inert atmosphere protection after the drying is completed.

2. The production method according to claim 1, characterized by, The coated metal shell of the catalyst has a thickness of 5-20 nm, and the coated metal loading is 20-70 wt.%.

3. The preparation method according to claim 1, characterized in that The surfactant is hexadecyl trimethyl ammonium bromide or polyvinyl pyrrolidone or sodium dodecyl sulfate.

4. The method of claim 1, wherein, The mass-volume ratio of the metal titanium powder to ethylene glycol is 0.1 mg:1 mL-2 mg:1 mL, and the molar ratio of the surfactant to iridium or ruthenium in the precursor is 0.1 mol:1 mol-10 mol:1 mol.

5. The preparation method according to claim 1, characterized in that The iridium precursor is chloroiridic acid, potassium chloroiridate, iridium trichloride, iridium acetate or acetylacetone iridium, the ruthenium precursor is ruthenium trichloride, ruthenium acetate, potassium chlororuthenate, chlororuthenic acid or acetylacetone ruthenium, and the inert protective gas during the ethylene glycol reflux reduction reaction is nitrogen or argon.

6. The method of claim 1, wherein, The ultrasonic dispersing time is 0.5-5 h, the stirring time after adding the iridium precursor or the ruthenium precursor is 0.5-5 h, the ethylene glycol reflux reduction reaction temperature is 140-200℃, the ethylene glycol reflux reduction reaction time is 1-5 h, and the centrifugal separation operating condition is a rotation speed of 10000-15000 rpm and a time of 3-5 min.

7. The preparation method according to claim 1, characterized in that The organic solvent used in the centrifugal washing process is ethanol or isopropyl alcohol or trichloromethane or acetone.

8. The method of claim 1, wherein, The vacuum freeze-drying time is 8-24 h, and the inert protective atmosphere used for sampling after the drying is completed is nitrogen or argon.

9. An electrolytic water catalyst with a dense coated shell structure prepared by the preparation method of any one of claims 1-8.

10. Application of the electrolytic water catalyst with a dense coated shell structure of claim 9 as a proton exchange membrane water electrolysis oxygen catalyst in water electrolysis hydrogen production.

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