Doped titanium dioxide catalyst carrier, anode catalyst and preparation method and application thereof

Abstract

The invention relates to the technical field of electrochemistry, in particular to a doped titanium dioxide catalyst carrier, an anode catalyst and a preparation method and application thereof. Mixing water, an alcohol compound, a pH regulator, glacial acetic acid, a doped element precursor and the SiO2 microspheres to obtain a mixed solution; dropwise adding an alcoholic solution of organic titanium salt into the mixed solution to form sol, and standing to obtain gel; drying the gel, and calcining to obtain a doped titanium dioxide catalyst carrier precursor; and etching SiO2 in the doped titanium dioxide catalyst carrier precursor by adopting a sodium hydroxide solution to obtain the doped titanium dioxide catalyst carrier. The doped titanium dioxide catalyst carrier provided by the invention not only overcomes the defect of insufficient chemical stability of the traditional carbon-based carrier, but also solves the problem that the Ir loading capacity is difficult to reduce due to small specific surface area and insufficient exposure of active sites of the existing catalyst carrier, and can still maintain the catalytic activity of the anode oxygen evolution reaction.

Description

Technical Field

[0001] The present invention relates to the field of electrochemistry technology, and particularly to a doped titanium dioxide catalyst support, an anode catalyst, and their preparation methods and applications. Background Art

[0002] As a key medium for large-scale storage and utilization of renewable energy, the efficient preparation technology of green hydrogen has become a research focus. Proton exchange membrane water electrolysis is favored due to its high current density and fast response characteristics. However, the anodic oxygen evolution reaction (OER) relies on catalysts with a high iridium (Ir) loading amount (>2 mg / cm 2 ), but iridium resources are scarce and costly, severely restricting the industrialization process. Using a support to load the active substance iridium is expected to reduce the loading amount of precious metals, promote charge transfer, and improve the activity and stability of the catalyst. Therefore, how to design a doped titanium dioxide catalyst support with low cost and high stability is one of the key issues in the field of hydrogen production by water electrolysis.

[0003] In the existing research on the anodic oxygen evolution catalytic system of proton exchange membrane (PEM) water electrolysis, researchers mostly use carbon-based materials or transition metal oxides as supports to load iridium metal (Ir) or iridium dioxide (IrO2). However, this technical solution has two key bottlenecks: on the one hand, carbon materials have low stability in proton exchange membrane water electrolysis, shortening the service life of the equipment; on the other hand, due to the relatively small specific surface area of some non-precious metal oxide supports, the number of active sites that can be exposed is limited, so the effect of reducing the loading amount of precious metal Ir is not significant, thereby weakening the catalytic efficiency. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the present invention provides a doped titanium dioxide catalyst support, an anode catalyst, and their preparation methods and applications. The present invention uses SiO2 microspheres, doping element precursors, and organic titanium salts as raw materials, and through the hard template method combined with the sol-gel technology, with SiO2 microspheres as the template and the introduction of doping element precursors, a doped titanium dioxide catalyst support is prepared, overcoming the defect of insufficient chemical stability of traditional carbon-based supports; at the same time, the doped titanium dioxide catalyst support prepared by the present invention has a honeycomb-like structure, making it have a large specific surface area, solving the problems of small specific surface area of the catalyst support in the existing technology, insufficient exposure of active sites, and difficulty in reducing the loading amount of precious metal Ir. In addition, by using the doped titanium dioxide catalyst support of the present invention to prepare an anode catalyst, while reducing the Ir dosage by 90%, excellent anodic oxygen evolution reaction catalytic activity is still maintained.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] The first object of the present invention is to provide a preparation method of a doped titanium dioxide catalyst support, comprising the following steps:

[0007] S1. Mix water, an alcohol compound, a pH regulator, glacial acetic acid, a doping element precursor, and SiO2 microspheres to obtain a mixed solution with a pH value of 2-5. Among them, if the alcohol solution of an organic titanium salt is directly contacted with the water in the mixed solution, precipitation will occur due to rapid hydrolysis, thus unable to form a microstructure. Therefore, it is necessary to dilute the organic titanium salt and water with the alcohol compound respectively. The glacial acetic acid in the mixed solution acts as a chelating agent. The alcohol compound not only serves as a diluent but also promotes the slow hydrolysis process of the organic titanium salt. Water is the basic raw material for the hydrolysis reaction, while the SiO2 microspheres serve as a template agent, providing a basis for the structure of the doped titanium dioxide catalyst support.

[0008] S2. Dropwise add the alcohol solution of the organic titanium salt into the mixed solution. Under acidic conditions, the organic titanium salt reacts with water in a hydrolysis reaction to generate Ti(OH)4 on the surface of the SiO2 microspheres. Ti(OH)4 undergoes dehydration condensation through a polycondensation reaction to form a Ti-O-Ti three-dimensional network structure, which coats around the SiO2 microspheres to form a sol; subsequently, the sol is allowed to stand, and the solvent molecules are wrapped in the gaps of the three-dimensional network structure and gradually lose fluidity, turning into a gel state to obtain a gel. Among them, if the one-time rapid addition method is adopted, it will cause supersaturation of the organic titanium salt in a local area, resulting in the Ti(OH)4 generated by the hydrolysis reaction being unable to be fully and evenly dispersed, and then aggregating to form larger particles.

[0009] S3. After drying and grinding the gel, perform a calcination treatment. During the calcination process, TiO2 changes from an amorphous state to anatase TiO2. At the same time, the doping element in the doping element precursor enters the TiO2 lattice to obtain a doped titanium dioxide catalyst support precursor.

[0010] S4. Etch the SiO2 in the doped titanium dioxide catalyst support precursor with a sodium hydroxide solution. During the etching process, sodium hydroxide reacts with SiO2 to gradually strip the silica layer on the surface, while ensuring that the doped titanium dioxide structure inside the doped titanium dioxide catalyst support precursor is not significantly damaged. After centrifugation, washing, and drying treatments, a doped titanium dioxide catalyst support is obtained.

[0011] Preferably, the mass ratio of the doping element precursor to the SiO2 microspheres is 0.05-0.2:1, the molar ratio of the doping element precursor to water is 0.00005-0.001:1, and the volume ratio of water to the alcohol compound is 0.2-0.3:1.

[0012] Preferably, the mass ratio of the organic titanium salt in the organic titanium salt alcohol solution to the water in the mixed solution is 0.8-1:1.

[0013] Preferably, in the alcohol solution of the organotitanium salt, the volume ratio of the organotitanium salt to the alcohol compound is 1:0.2 to 0.3.

[0014] Preferably, the organotitanium salt is selected from tetrabutyl titanate, isopropyl titanate, titanium tetrachloride or titanium sulfate.

[0015] Preferably, the dopant element precursor is selected from ammonium metatungstate hydrate, niobium ethanolate, titanium diboride or ammonium fluoride.

[0016] Preferably, the concentration of the sodium hydroxide solution is 0.1 mol / L to 1 mol / L. Among them, if the concentration of the sodium hydroxide solution is too low, SiO2 cannot be etched cleanly; if the concentration of the sodium hydroxide solution is too high, it will cause difficulties in cleaning the doped titanium dioxide catalyst support.

[0017] Preferably, the conditions for the calcination treatment are: heating at a heating rate of 0.5 °C / min to 10 °C / min and calcining at 350 °C to 500 °C for 0.5 h to 4 h.

[0018] Preferably, the static condition is: standing at room temperature for 24 h to 72 h. Before standing, it is a sol, and after standing, it is a gel. The gel is jelly-like, and the shape of the gel will not change when the container is tilted.

[0019] Preferably, in step S4, the sodium hydroxide solution and the precursor of the doped titanium dioxide catalyst support are mixed by ultrasonic dispersion. The conditions for ultrasonic dispersion are: ultrasonic dispersion at 50 W to 100 W for 3 min to 60 min.

[0020] Preferably, the etching conditions are: heating at 60 °C to 80 °C for 6 h to 12 h.

[0021] Preferably, the centrifugation conditions are: centrifuging at 5000 rpm to 8000 rpm for 5 min to 10 min.

[0022] Preferably, the gel drying method is selected from vacuum drying, freeze drying or hot air drying, and the physical water brought in during the centrifugation process is removed as completely as possible; among them, the conditions for vacuum drying are: drying at 40 to 90 °C for 24 h to 48 h.

[0023] Preferably, in step S4, if the drying method is vacuum drying or hot air drying, it is dried at a temperature of 60 °C to 80 °C for 24 h to 48 h; if the drying method is freeze drying, it is freeze dried at -50 °C to -60 °C for 24 h to 48 h.

[0024] Preferably, the pH regulator is selected from concentrated hydrochloric acid or concentrated nitric acid.

[0025] Preferably, the diameter of the SiO2 microspheres is 200 nm to 1000 nm.

[0026] The second object of the present invention is to provide a doped titanium dioxide catalyst support prepared by the above preparation method.

[0027] Preferably, the doped titanium dioxide catalyst support has a honeycomb-like structure, and the honeycomb-like structure is formed by connecting several bowl-shaped structures.

[0028] The third object of the present invention is to provide the above-mentioned anode catalyst, which is prepared by using the above-mentioned doped titanium dioxide catalyst support, soluble Ir salt and sodium hydroxide.

[0029] Preferably, the preparation method of the anode catalyst includes the following steps:

[0030] Disperse the doped titanium dioxide catalyst support in water, add soluble Ir salt and sodium hydroxide to obtain a suspension; seal the suspension and perform heat treatment, and then centrifuge and dry to obtain the anode catalyst.

[0031] The fourth object of the present invention is to provide the application of the above anode catalyst in oxygen evolution of proton exchange membrane electrolyzed water.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] 1. The present invention provides a preparation method of a doped titanium dioxide catalyst support. Water, an alcohol compound, a pH regulator, a chelating agent glacial acetic acid, a doping element precursor, and a templating agent SiO2 microsphere are mixed to obtain a mixed solution with a pH value of 2 to 5. The doping element precursor is selected from ammonium metatungstate hydrate, niobium ethoxide, titanium diboride, or ammonium fluoride. An alcohol solution of an organic titanium salt is added dropwise to the mixed solution. Under acidic conditions, the organic titanium salt undergoes a hydrolysis reaction with water to form Ti(OH)4 on the surface of the SiO2 microsphere. Ti(OH)4 undergoes dehydration condensation through a polycondensation reaction to form a Ti-O-Ti three-dimensional network structure, which coats around the SiO2 microsphere to form a sol. Subsequently, the sol is allowed to stand to obtain a gel. The gel is dried and ground, and then calcined. During the calcination process, TiO2 changes from an amorphous state to anatase TiO2. At the same time, the doping element in the doping element precursor enters the TiO2 lattice to obtain a precursor of the doped titanium dioxide catalyst support. The SiO2 in the precursor of the doped titanium dioxide catalyst support is etched with a sodium hydroxide solution, and after centrifugation, washing, and drying treatments, a doped titanium dioxide catalyst support is obtained. The present invention combines the hard template method with the sol-gel method to coat doped titanium dioxide on the SiO2 microsphere, and then etches away SiO2 with NaOH. After drying, a doped titanium dioxide catalyst support is obtained. The doped titanium dioxide catalyst support prepared by the present invention not only overcomes the defect of insufficient chemical stability of traditional carbon-based supports, but also solves the problems of small specific surface area, insufficient exposure of active sites, and difficulty in reducing the noble metal Ir loading amount in the prior art.

[0034] 2. The doped titanium dioxide catalyst support prepared by the preparation method of the present invention has a honeycomb-like structure, large specific surface area, high electrical conductivity, and high stability, and can significantly reduce the noble metal Ir loading amount. For stability, TiO2 itself has high antioxidant and corrosion resistance capabilities.

[0035] 3. Compared with the commercial iridium-based catalyst widely used in the field of proton exchange membrane electrolysis of water, the noble metal iridium loading amount thereof is conventionally maintained at about 2 mg / cm 2 level. However, the anode catalyst prepared by using 15% W-TiO2 prepared by the present invention as a support shows significant advantages in a three-electrode test system. Specifically, 30% IrO2 / 15% W-TiO2 has an overpotential of only 278 mV at a current density of 10 mA / cm 2 , and this value is much lower than 320 mV of the commercial catalyst, which strongly proves its excellent catalytic activity. In addition, in a continuous constant current test of 10 mA / cm 2 , this anode catalyst can maintain a high stability performance for up to 100 h. It is particularly worth mentioning that at this time, the iridium loading amount in the anode catalyst is only 0.206 mg / cm2 , it has decreased by one order of magnitude. Description of the Drawings

[0036] Figure 1 This is the SEM image of the doped titanium dioxide catalyst support of Example 1 of the present invention.

[0037] Figure 2 This is the LSV graph of the anode catalyst prepared from the doped titanium dioxide catalyst supports of Application Example 1 and Application Example 2.

[0038] Figure 3 This is the CP curve graph of the anode catalyst prepared from the doped titanium dioxide catalyst support of Application Example 1 at a constant current density of 10 mA / cm 2 Detailed Embodiments

[0039] Next, the technical solutions of the present invention will be clearly and completely described in combination with the data in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0040] It should be noted that the professional terms used in the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the protection scope of the present invention. Unless otherwise specifically stated, all kinds of raw materials, reagents, instruments and equipment used in the following embodiments of the present invention can be obtained through market purchase or prepared by existing methods.

[0041] In the prior art, although researchers have tried various methods to improve the efficiency and reduce the cost of the oxygen evolution reaction in proton exchange membrane electrolyzed water, many challenges are still faced. Although carbon-based materials have good electrical conductivity, their chemical stability is insufficient and they are prone to corrosion during the electrolyzed water process, thus affecting the service life of the catalyst. While transition metal oxide supports are relatively stable, their specific surface area is small and the active sites are limitedly exposed, making it difficult to effectively reduce the loading of precious metal Ir, thereby limiting the improvement of catalytic performance.

[0042] ​In view of the problems existing in the above-mentioned prior art, the present invention provides a method for preparing a doped titanium dioxide catalyst support, which includes the following steps: Mix water, an alcohol compound, a pH regulator, a chelating agent glacial acetic acid, a doping element precursor, and a templating agent SiO2 microspheres to obtain a mixed solution with a pH value of 2-5; the doping element precursor is selected from ammonium metatungstate hydrate, niobium ethoxide, titanium diboride, or ammonium fluoride; dropwise add an alcohol solution of an organic titanium salt to the mixed solution, and under acidic conditions, the organic titanium salt undergoes a hydrolysis reaction with water to form Ti(OH)4 on the surface of the SiO2 microspheres. Ti(OH)4 undergoes a polycondensation reaction to dehydrate and condense, forming a Ti-O-Ti three-dimensional network structure, which coats around the SiO2 microspheres to form a sol; then let the sol stand to obtain a gel; dry and grind the gel, and then perform a calcination treatment. During the calcination treatment, TiO2 changes from an amorphous state to anatase TiO2, and at the same time, the doping elements in the doping element precursor enter the TiO2 lattice to obtain a doped titanium dioxide catalyst support precursor; use a sodium hydroxide solution to etch the SiO2 in the doped titanium dioxide catalyst support precursor, and after centrifugation, washing, and drying treatments, obtain a doped titanium dioxide catalyst support.

[0043] Aiming at the dual problems that the chemical stability of the carbon-based support is insufficient, leading to a shortened catalyst life, and the specific surface area of the non-noble metal oxide support is limited, making it difficult to effectively reduce the Ir loading. The doped titanium dioxide catalyst support obtained by the present invention through the hard template method combined with the sol-gel technology has a honeycomb-like structure that not only provides a specific surface area far exceeding that of traditional oxide supports, but also the synergistic effect formed by the doping elements and the TiO2 lattice significantly optimizes the charge transfer efficiency. In addition, while maintaining the high dielectric constant characteristics of anatase TiO2, the number of active sites exposed per unit mass of Ir is increased, thereby breaking through the linear dependence relationship between the noble metal dosage and the catalytic activity, and achieving an oxygen evolution performance superior to that of commercial catalysts under an ultra-low Ir loading of 0.206 mg / cm 2

[0044] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the following will specifically describe the technical solution of the present invention in detail with reference to specific embodiments:

[0045] Example 1

[0046] A method for preparing a doped titanium dioxide catalyst support includes the following steps:

[0047] S1. Mix 2 mL of tetrabutyl titanate and 7 mL of ethanol to obtain an ethanol solution of tetrabutyl titanate; mix 2 mL of water, 7 mL of ethanol, 4 μL of concentrated hydrochloric acid, 0.8 mL of glacial acetic acid, 138.4 mg of ammonium metatungstate hydrate, and 1.6 g of SiO2 microspheres to obtain a mixed solution.

[0048] S2. While stirring, dropwise add the ethanol solution of tetrabutyl titanate into the second mixture to form a sol. After standing for 24 h, a gel is formed.

[0049] S3. First, dry the gel in a vacuum at 40 °C for 48 h, then grind it. Subsequently, place it in a muffle furnace and heat it to 500 °C at a rate of 0.5 °C / min for calcination for 0.5 h to obtain 15% W-TiO2@SiO2.

[0050] S4. Mix 1 g of 15% W-TiO2@SiO2 with 100 mL of 0.5 mol / L sodium hydroxide aqueous solution, and ultrasonically disperse it for 3 min at an ultrasonic power of 100 W to obtain a dispersion; place the dispersion in an oven, heat it to 60 °C to etch SiO2 for 12 h. After the etching is completed, centrifuge at 5000 rpm for 10 min to obtain a precipitate; subsequently, wash the precipitate with ultrapure water. Finally, dry it at 80 °C for 24 h to obtain a doped titanium dioxide catalyst support, denoted as 15% W-TiO2.

[0051] Example 2

[0052] A preparation method of a doped titanium dioxide catalyst support includes the following steps:

[0053] S1. Mix 2 mL of tetrabutyl titanate with 7 mL of ethanol to obtain an ethanol solution of tetrabutyl titanate; mix 2 mL of water, 7 mL of ethanol, 4 μL of concentrated hydrochloric acid, 0.8 mL of glacial acetic acid, 41.3 mg of ammonium metatungstate hydrate and 1.6 g of SiO2 microspheres to obtain a mixed solution.

[0054] S2. While stirring, dropwise add the ethanol solution of tetrabutyl titanate into the second mixture to form a sol. After standing for 24 h, a gel is formed.

[0055] S3. First, dry the gel in a vacuum at 40 °C for 48 h, then grind it. Subsequently, place it in a muffle furnace and heat it to 500 °C at a rate of 0.5 °C / min for calcination for 0.5 h to obtain 5% W-TiO2.

[0056] S4. Mix 1 g of 5% W-TiO2@SiO2 with 100 mL of 0.5 mol / L sodium hydroxide aqueous solution, and ultrasonically disperse it for 3 min at an ultrasonic power of 100 W to obtain a dispersion; place the dispersion in an oven, heat it to 60 °C to etch SiO2 for 12 h. After the etching is completed, centrifuge at 5000 rpm for 10 min to obtain a precipitate; subsequently, wash the precipitate with ultrapure water. Finally, dry it at 80 °C for 24 h to obtain a doped titanium dioxide catalyst support, denoted as 5% W-TiO2.

[0057] Example 3

[0058] A preparation method of a doped titanium dioxide catalyst support, comprising the following steps:

[0059] S1. Mix 1.6 mL of tetrabutyl titanate and 10 mL of ethanol to obtain an ethanol solution of tetrabutyl titanate; mix 2 mL of water, 10 mL of ethanol, 20 μL of concentrated hydrochloric acid, 0.6 mL of glacial acetic acid, 16.4 mg of ammonium metatungstate hydrate and 328.4 mg of SiO2 microspheres to obtain a mixed solution.

[0060] S2. Under stirring, gradually add the ethanol solution of tetrabutyl titanate dropwise to the second mixed solution to form a sol. After standing for 72 h, a gel is formed.

[0061] S3. First, dry the gel in a vacuum at 90 °C for 24 h, then grind it, and then place it in a muffle furnace and heat it to 350 °C at a rate of 10 °C / min for calcination for 4 h to obtain 9% W-TiO2@SiO2.

[0062] S4. Mix 1 g of 9% W-TiO2@SiO2 and 100 mL of 1 mol / L sodium hydroxide aqueous solution, and ultrasonically disperse it at an ultrasonic power of 50 W for 60 min to obtain a dispersion; place the dispersion in an oven, heat it to 80 °C to etch SiO2 for 6 h. After the etching is completed, centrifuge at 8000 rpm for 5 min to obtain a precipitate; then wash the precipitate with ultrapure water, and finally dry it at 60 °C for 48 h to obtain a doped titanium dioxide catalyst support.

[0063] Example 4

[0064] A preparation method of a doped titanium dioxide catalyst support, comprising the following steps:

[0065] S1. Mix 3 mL of tetrabutyl titanate and 10 mL of ethanol to obtain an ethanol solution of tetrabutyl titanate; mix 3 mL of water, 10 mL of ethanol, 30 μL of concentrated hydrochloric acid, 1 mL of glacial acetic acid, 492.7 mg of ammonium metatungstate hydrate and 2.46 g of SiO2 microspheres to obtain a mixed solution.

[0066] S2. Under stirring, gradually add the ethanol solution of tetrabutyl titanate dropwise to the second mixed solution to form a sol. After standing for 72 h, a gel is formed.

[0067] S3. First, dry the gel in a vacuum at 90 °C for 24 h, then grind it, and then place it in a muffle furnace and heat it to 350 °C at a rate of 10 °C / min for calcination for 4 h to obtain 19% W-TiO2@SiO2.

[0068] S4. Mix 1 g of 19% W-TiO2@SiO2 with 100 mL of 1 mol / L sodium hydroxide aqueous solution, and then ultrasonically disperse it for 60 min at an ultrasonic power of 50 W to obtain a dispersion. Place the dispersion in an oven, heat it to 80 °C to etch SiO2 for 6 h. After the etching is completed, centrifuge at 8000 rpm for 5 min to obtain a precipitate. Subsequently, wash the precipitate with ultrapure water, and finally dry it at 60 °C for 48 h to obtain a doped titanium dioxide catalyst support.

[0069] Example 5

[0070] A preparation method of a doped titanium dioxide catalyst support is the same as the preparation steps of Example 1, except that 138.4 mg of ammonium metatungstate hydrate in step S1 of Example 1 is replaced with 33.0 mg of niobium ethanolate to obtain a doped titanium dioxide catalyst support.

[0071] Example 6

[0072] A preparation method of a doped titanium dioxide catalyst support is the same as the preparation steps of Example 1, except that 138.4 mg of ammonium metatungstate hydrate in step S1 of Example 1 is replaced with 72.1 mg of titanium diboride to obtain a doped titanium dioxide catalyst support.

[0073] Example 7

[0074] A preparation method of a doped titanium dioxide catalyst support is the same as the preparation steps of Example 1, except that 138.4 mg of ammonium metatungstate hydrate in step S1 of Example 1 is replaced with 38.4 mg of ammonium fluoride to obtain a doped titanium dioxide catalyst support.

[0075] Observation Figure 1 It is concluded that the surface of the doped titanium dioxide catalyst support in Example 1 exhibits unique honeycomb-like structural characteristics, and this structure is composed of bowl-shaped hemispherical shell morphologies.

[0076] Doped titanium dioxide catalyst supports were prepared in Examples 1 to 7. Taking 15% W-TiO2 of Example 1 and 5% W-TiO2 of Example 2 as examples, anode catalysts were prepared.

[0077] Weigh 30 mg of 15% W-TiO2 and 5% W-TiO2, and place them separately in 3.5 mL of ultrapure water. Use an ultrasonic cleaner to perform dispersion treatment at room temperature for 30 min to form a uniform dispersion system. Subsequently, add 27.6 mg of IrCl3 and 8 mg of sodium hydroxide to the two groups of dispersions respectively. After dissolution by magnetic stirring, a suspension is obtained; transfer the suspension to a 10 mL high-pressure reaction kettle lined with polytetrafluoroethylene and seal it. Place it in a constant-temperature forced-air drying oven and carry out hydrothermal reaction at 160 °C for 12 h. After the reaction, naturally cool it to room temperature. The obtained product is centrifuged at 8000 rpm for 36 h, then repeatedly washed with deionized water, and then subjected to freeze treatment using a vacuum freeze dryer to obtain anode catalysts, denoted as 30% IrO2 / 15% W-TiO2 catalyst and 30% IrO2 / 5% W-TiO2 catalyst respectively.

[0078] Weigh 2.5 mg of 30% IrO2 / 15% W-TiO2 catalyst and 30% IrO2 / 5% W-TiO2 catalyst respectively, place them in 2 mL centrifuge tubes, add 950 μL of isopropanol, and then place them in an ultrasonic cleaner for ultrasonic dispersion for 30 min to form a preliminary suspension; subsequently, drop 50 μL of Nafion solution into the system and continue ultrasonic treatment for 30 min to obtain a catalyst slurry; use a microinjector to quantitatively transfer 10 μL of the catalyst slurry three times and vertically drop it onto the surface of a glassy carbon electrode with a diameter of 0.3 cm; after each drop coating, place the electrode in a clean environment and let it air dry naturally, and then carry out the next drop coating to obtain glassy carbon electrodes loaded with catalysts, denoted as 30% IrO2 / 15% W-TiO2 and 30% IrO2 / 5% W-TiO2 respectively.

[0079] Use commercially available IrO2 / TiO2, 30% IrO2 / 15% W-TiO2, and 30% IrO2 / 5% W-TiO2 as working electrodes, Hg / Hg2SO4 as the reference electrode, and a carbon rod as the counter electrode. Place one end of the working electrode, reference electrode, and counter electrode in a 0.5 mol / L sulfuric acid solution, and the other ends are commonly electrically connected to an electrochemical workstation to conduct electrochemical performance tests.

[0080] Test conditions:

[0081] a. Polarization curve test: After the glassy carbon electrode loaded with the catalyst is activated, obtain the polarization curve of the glassy carbon electrode loaded with the catalyst by linear sweep voltammetry. The scanning voltage range is 1.2 V vs RHE to 1.7 V vs RHE, the scanning rate is 5 mV / s, and to avoid the appearance of oxidation-reduction peaks, the scanning direction is reverse scanning.

[0082] b. Chronopotentiometry (CP test): Using chronoamperometry, in the constant current density mode, the potential signal is monitored and collected in real time to construct a dynamic response curve of the potential evolution over time. The test duration is set to 100 h to evaluate the long-term electrochemical stability of the catalyst. The current density is 10 mA / cm 2 .

[0083] It was observed that Figure 2 for the 30% IrO2 / 15% W-TiO2 prepared with the doped titanium dioxide catalyst support of Application Example 1, the overpotential at a current density of 10 mA / cm 2 was only 278 mV, and for the 30% IrO2 / 5% W-TiO2 prepared with the doped titanium dioxide catalyst support of Application Example 2, the overpotential was 288 mV, both being much lower than the overpotential of the commercially available IrO2 / TiO2 (320 mV), indicating that the catalyst prepared with the doped titanium dioxide catalyst support of the present invention has good electrochemical activity.

[0084] It was observed that Figure 3 for the 30% IrO2 / 15% W-TiO2 prepared with the doped titanium dioxide catalyst support of Application Example 1, the potential increase rate was only 0.242 mV / h@100 h in the constant current test at 10 mA / cm 2 , indicating its good stability.

[0085] It should be noted that when the present invention involves a numerical range, it should be understood that any value between the two endpoints of each numerical range and either of the two endpoints can be selected. Since the steps and methods adopted are the same as those in the embodiments, in order to prevent repetition, the present invention describes the preferred embodiments. Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

Claims

1. A preparation method of a doped titanium dioxide catalyst support, characterized in that, It includes the following steps: Mix water, alcohol compounds, pH regulator, chelating agent glacial acetic acid, doping element precursor and templating agent SiO2 microspheres to obtain a mixed solution with a pH value of 2 to 5; The doping element precursor is selected from ammonium metatungstate hydrate, niobium ethanolate, titanium diboride or ammonium fluoride; Dropwise add the alcohol solution of organic titanium salt into the mixed solution. Under acidic conditions, the organic titanium salt undergoes hydrolysis reaction with water to generate Ti(OH)4 on the surface of SiO2 microspheres. Ti(OH)4 dehydrates and condenses through polycondensation reaction to form a Ti-O-Ti three-dimensional network structure, which coats around the SiO2 microspheres to form a sol; then let the sol stand to obtain a gel; After drying and grinding the gel, carry out calcination treatment. During the calcination treatment, TiO2 changes from amorphous state to anatase TiO2. At the same time, the doping elements in the doping element precursor enter the TiO2 lattice to obtain a doped titanium dioxide catalyst support precursor; Etch SiO2 in the doped titanium dioxide catalyst support precursor with sodium hydroxide solution, and after centrifugation, washing and drying, obtain the doped titanium dioxide catalyst support.

2. The preparation method of the doped titanium dioxide catalyst carrier according to claim 1, characterized in that, The mass ratio of the doping element precursor to SiO2 microspheres is 0.05 to 0.2:1, the molar ratio of the doping element precursor to water is 0.00005 to 0.001:1, the volume ratio of water to alcohol compounds is 0.2 to 0.3:1, and the volume ratio of glacial acetic acid to water is 0.3 to 0.5:

1.

3. The preparation method of the doped titanium dioxide catalyst support according to claim 1, characterized in that, The mass ratio of the organic titanium salt in the organic titanium salt alcohol solution to the water in the mixed solution is 0.8 to 1:

1.

4. The preparation method of the doped titanium dioxide catalyst support according to claim 1, wherein, The conditions for the calcination treatment are: calcine at 350°C to 500°C for 0.5 h to 4 h.

5. The preparation method of the doped titanium dioxide catalyst support according to claim 1, characterized in that, The concentration of the sodium hydroxide solution is 0.1 mol / L to 1 mol / L.

6. A doped titanium dioxide catalyst support prepared by the preparation method of the doped titanium dioxide catalyst support according to any one of claims 1 to 5.

7. The doped titanium dioxide catalyst support according to claim 6, characterized in that The doped titanium dioxide catalyst support has a honeycomb-like structure, and the honeycomb-like structure is formed by connecting several bowl-like structures.

8. An anode catalyst, characterized in that, The anode catalyst is prepared from the doped titanium dioxide catalyst support according to claim 7, soluble Ir salt and sodium hydroxide.

9. The method for preparing the anode catalyst according to claim 8, wherein, It includes the following steps: Disperse the doped titanium dioxide catalyst support in water, and add soluble Ir salt and sodium hydroxide to obtain a suspension; Seal the suspension and carry out heat treatment, and after centrifugation and drying, obtain the anode catalyst.

10. An application of the anode catalyst according to claim 8 in the preparation of a proton exchange membrane electrolytic water oxygen evolution reaction catalyst.

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