Preparation method of titanium dioxide nanobelt carrier and PEM electrolyzed water anode catalyst

Abstract

The invention provides a preparation method of a titanium dioxide nanobelt carrier and a PEM electrolyzed water anode catalyst, belongs to the technical field of PEM electrolyzed water hydrogen production, and aims to solve the technical problem of poor catalytic activity of a titanium dioxide-based catalyst. The titanium dioxide nanobelt carrier disclosed by the invention is a doped type titanium dioxide nanobelt carrier; the doping element is at least one of sulfur and selenium; the carrier is in a nanobelt shape. Through morphology regulation and doping modification, by adopting the titanium dioxide nanobelt carrier in the invention, on one hand, the gas-liquid mass transfer behavior of the membrane electrode during operation can be regulated, and on the other hand, the conductivity of the membrane electrode is improved; therefore, the anode material shows excellent activity in the aspect of PEM electrolyzed water anode reaction activity (the use amount of noble metal is reduced by 70% under the approximate electrolytic performance condition) and long service life (the anode material continuously operates for 1000 hours under the constant current of 1A cm <-2 >), and the energy conversion efficiency is obviously improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of PEM electrolytic water hydrogen production, and particularly relates to an anode catalyst. BACKGROUND

[0002] With the rapid development of renewable energy, water electrolysis driven by renewable energy has become an important part of the future energy system because it can realize efficient conversion and storage of clean energy. Among them, the proton exchange membrane water electrolysis (PEMWE) technology has higher current density and faster response speed, so it can be more quickly matched with renewable energy. However, the anode oxygen evolution reaction (OER) of PEMWE has a slow kinetics, which limits the reaction rate and requires a high overpotential drive. At the same time, the anode reaction faces a strong acidic environment, which has a high requirement for the activity and stability of the catalyst. At present, iridium-based noble metal catalysts are materials that maintain high catalytic activity under the harsh reaction conditions of PEM electrolysis cells, but the iridium reserves in the earth's crust are limited, resulting in high cost of iridium-based noble metal catalysts, which limits the large-scale promotion of PEMWE. Therefore, developing an acidic OER catalyst with high activity, high stability and low noble metal content has become a research focus.

[0003] In order to reduce the use of noble metals, the strategy of loading noble metals on metal oxide carriers with good chemical stability is usually adopted. Titanium dioxide is considered to be one of the main candidates for PEM electrolytic water catalyst carriers due to its strong acid resistance and corrosion resistance. However, traditional catalysts are generally in granular or agglomerated structure, which can limit the gas evolution and electrolyte penetration channels in the membrane electrode structure, form a mass transfer resistance layer, and thus reduce the reaction efficiency and stability. In addition, the conductivity of titanium dioxide itself is low, which further limits its application under high current density conditions.

[0004] The prior art usually adopts the method of element doping to improve the activity of the anode catalyst. For example, patent publication CN118291989A discloses a PEM electrolytic water anode catalyst carrier and a preparation method thereof. The PEM electrolytic water anode catalyst carrier is a doped titanium dioxide with oxygen defects, and the molecular formula is A x Ti 1-x O 2-δWherein, 0 < x < 1, 0 < δ < 2, A includes at least one of Sn, Sb, Nb, Ta. The patent solves the problems of low activity and stability of Ir-based anode catalyst by using oxygen defect doped titanium dioxide as a carrier in a PEM water electrolysis device and compounding Ir with other noble metals. The patent realizes high performance and low cost of acidic water electrolysis oxygen evolution effect. Patent No. CN120272950A discloses a doped titanium dioxide catalyst carrier, an anode catalyst and a preparation method and application thereof. Water, alcohol compounds, pH regulators, glacial acetic acid, doped element precursors and SiO2 microspheres are mixed to obtain a mixed solution. An alcohol solution of organic titanium salt is added dropwise to the mixed solution, and after the sol is formed, the gel is obtained. The gel is dried and calcined to obtain a doped titanium dioxide catalyst carrier precursor. The SiO2 in the doped titanium dioxide catalyst carrier precursor is etched with a sodium hydroxide solution to obtain a doped titanium dioxide catalyst carrier. The patent prepares a doped titanium dioxide catalyst carrier by a hard template method and a sol-gel technology, solves the problems of insufficient stability of carbon-based materials and small specific surface area of non-noble metal oxides, and realizes the improvement of high-efficiency anode catalyst performance and stability. However, the performance of the above-mentioned titanium dioxide-based catalyst is still limited by the insufficient cooperation design of the carrier morphology and the doped elements. On the one hand, the micro-morphology of the traditional titanium dioxide carrier cannot fully expose the active sites, resulting in low utilization rate of noble metal active components; on the other hand, the introduction of conventional doped elements cannot effectively improve the electron conductivity efficiency of the carrier, resulting in poor overall conductivity of the catalyst, which further restricts the improvement of OER catalytic activity. Therefore, it is of great significance to develop a new type of titanium dioxide-based anode catalyst with high active site exposure rate, excellent conductivity and strong catalytic activity for promoting the industrial application of PEM water electrolysis technology. SUMMARY

[0005] In view of the technical problem of poor catalytic activity of the titanium dioxide-based catalyst, the present application provides a preparation method of a titanium dioxide nanobelt carrier and a PEM water electrolysis anode catalyst. Through morphology control and doping modification, the titanium dioxide nanobelt carrier in the present application can control the gas-liquid mass transfer behavior during the operation of the membrane electrode, and improve the conductivity, so as to exhibit excellent activity (the amount of noble metal is reduced by 70% under the condition of similar electrolysis performance) and service life (1000 hours of continuous operation under constant current) in the PEM water electrolysis anode reaction activity, so as to significantly improve the energy conversion efficiency. -2 Constant current for 1000 hours.

[0006] In order to achieve the above-mentioned purposes, the technical scheme of the present application is as follows: A titanium dioxide nanobelt carrier, the preparation method comprising the following steps: (1) preparing a titanium dioxide nanobelt by a hydrothermal method; (2) The titanium dioxide nanobelt carrier is prepared by doping sulfur or selenium element through a gas deposition method by placing the titanium dioxide nanobelt and the doping element precursor in a tube furnace.

[0007] The step of the hydrothermal method for preparing the titanium dioxide nanobelt is that a titanium source is added into an alkali solution to perform a hydrothermal reaction to prepare a titanate precursor; the titanate precursor is dispersed in an acid solution to perform ion exchange to prepare a titanic acid precursor, and the titanic acid precursor is calcined to prepare the titanium dioxide with a nanobelt morphology.

[0008] The titanium source is titanium dioxide or titanium trioxide; the alkali solution is a sodium hydroxide solution or a potassium hydroxide solution with a concentration of 5-10 mol / L; the concentration of the titanium source in the alkali solution is 1-5 mg / mL; the temperature of the hydrothermal reaction is 160-200 ℃, and the time is 12-24 h.

[0009] The acid solution is a hydrochloric acid solution or a nitric acid solution with a concentration of 0.1-1 mol / L; the concentration of the titanate precursor in the acid solution is 0.5-5 mg / mL; and the time of the ion exchange is 12-36 h.

[0010] The calcination temperature is 400-600 ℃, and the time is 1.5-3.5 h.

[0011] The doping element precursor is sulfur powder or selenium powder; the molar ratio of the titanium dioxide precursor to the doping element precursor is 1:1-8; the gas deposition method is in an argon gas or a hydrogen-argon mixed gas, the gas flow is 50-200 mL / min, the calcination temperature is 400-600 ℃, the time is 1.5-3.5 h, and the temperature rising rate is 1-10 ℃ / min.

[0012] A PEM electrolytic water anode catalyst includes a titanium dioxide nanobelt carrier and a supported noble metal, and the noble metal loading is 5-50 wt%. A preparation method of the PEM electrolytic water anode catalyst includes the following steps: dispersing and dissolving the titanium dioxide nanobelt carrier, a surfactant and a soluble noble metal precursor into a solvent to prepare the PEM electrolytic water anode catalyst after reaction.

[0013] The surfactant is one or two or more of cetyltrimethylammonium bromide, cetyltrimethylammonium chloride or polyvinyl butyral; the soluble noble metal precursor is one or two or more of iridium trichloride hydrate, iridium tetrachloride, chloroiridic acid hydrate, ammonium hexachloroiridate, ruthenium trichloride or ammonium chlororuthenate; and the solvent is one or two or more of water, anhydrous ethanol, isopropyl alcohol or ethylene glycol.

[0014] The concentration of the titania nanoribbon carrier in the solvent is 1-5 mg / mL; the amount of the soluble noble metal precursor is calculated according to the noble metal loading in the PEM electrolytic water anode catalyst; the molar ratio of the soluble noble metal precursor to the surfactant is 1:1-4; the reaction temperature is 150-190 DEG C, and the reaction time is 1-3 h.

[0015] The beneficial effects of the present application are: (1) By introducing a nanoribbon-type titania carrier stable under acidic conditions, the morphology has a high specific surface area and abundant surface active sites, which can realize uniform dispersion and efficient loading of noble metal iridium nanoparticles. As a result, in the actual application scenario of the PEM electrolytic tank, the catalyst of the present application can ensure high catalytic activity while significantly reducing the amount of noble metal, for example, the membrane electrode iridium loading is only 0.3 mg・cm -2 , and the electrolysis voltage is as low as 1.66 V under a current density of 1A・cm -2 . Compared with a commercial iridium oxide catalyst (iridium loading of 1 mg・cm -2 ), the amount of iridium is reduced by 70% when the activity is close. This not only greatly improves the utilization rate of unit noble metal atoms, but also significantly reduces the overall material cost of the catalyst while ensuring high catalytic activity, which has outstanding industrial application advantages.

[0016] (2) Compared with traditional granular or agglomerated carriers, the catalyst formed by loading noble metal iridium on nanoribbon-type titania has a through multi-level pore structure and one-dimensional electron transmission path, which can form a continuous and controllable gas-liquid diffusion network. This structure can significantly improve the supply rate of reactants (H2O) to active sites during the operation of the membrane electrode, and at the same time, help the reaction products (O2) to be discharged in time, reduce the local blockage effect caused by bubble accumulation, thereby effectively reducing the gas-liquid mass transfer resistance and polarization loss in the electrolysis process; more importantly, the optimized mass transfer channel can avoid local concentration-induced uneven electrode aging, significantly improving the running stability of the membrane electrode, and the prepared catalyst can be stably operated for 1000 h under a current density of 1A・cm -2 , which exhibits excellent long-term stability.

[0017] (3) The sulfur family element doping introduced in the application can more effectively introduce a doping level into the titanium dioxide carrier, thereby narrowing the band gap; at the same time, it can also improve the electron transport efficiency and conductivity of the carrier, enhance the corrosion resistance of the carrier, regulate the binding energy of the iridium nanoparticles and the reaction intermediates, and ultimately significantly improve the OER activity of the iridium nanoparticles. In addition, the sulfur family element doping can also precisely regulate the hydrophilicity and hydrophobicity of the surface of the carrier, further optimize the gas-liquid transport efficiency in the membrane electrode reaction process, and synergistically improve the activity and service life of the catalyst, solving the activity and stability bottleneck of the traditional titanium dioxide-based catalyst due to poor electron transport and insufficient corrosion resistance. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0019] Figure 1 is the SEM graph of the titanate precursor in Example 1 of the application, (a) high magnification; (b) low magnification.

[0020] Figure 2 is the SEM graph of the titanium dioxide nanobelt carrier in Example 1 of the application.

[0021] Figure 3 is the XPS graph of the titanium dioxide nanobelt carrier of the application; (a) the titanium dioxide nanobelt carrier prepared in Example 1; (b) the titanium dioxide nanobelt carrier prepared in Example 13.

[0022] Figure 4 is the OER activity graph of the iridium catalyst loaded on the titanium dioxide nanobelt carrier in Example 1 of the application under a half-cell.

[0023] Figure 5 is the electrochemical impedance graph of the iridium catalyst loaded on the titanium dioxide nanobelt carrier in Example 1 of the application, the iridium catalyst loaded on the titanium dioxide nanobelt carrier in Example 13, Comparative Example 1 and Comparative Example 4 under a half-cell. Figure 6 is the activity test graph of the iridium catalyst loaded on the titanium dioxide nanobelt carrier in Example 1 of the application and the commercial iridium oxide catalyst in a PEM electrolytic cell.

[0024] Figure 7 is the constant current electrolysis test graph of the iridium catalyst loaded on the titanium dioxide nanobelt carrier in Example 1 of the application in a PEM electrolytic cell. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the protection scope of the present application.

[0026] Embodiment 1 A PEM electrolytic water anode catalyst, comprising a titanium dioxide nanobelt carrier and a supported noble metal, and the noble metal loading is 50 wt%. The preparation method of the PEM electrolytic water anode catalyst comprises the following steps: (1) 0.2 g of titanium dioxide is mixed with 40 ml of 10 mol / L sodium hydroxide solution, and then a hydrothermal reaction is carried out at 185 ℃ for 24 h. After the reaction, a precipitate is obtained, which is washed and dried to obtain a sodium titanate precursor. Then, the sodium titanate precursor is dispersed in a 0.1 mol / L hydrochloric acid solution to carry out an ion exchange reaction, and the concentration of the dispersed sodium titanate precursor is 1 mg / mL, and the ion exchange time is 24 h. After washing with deionized water for 5 times, the sodium titanate precursor is dried to obtain a titanic acid precursor. The titanic acid precursor is placed in a tube furnace and calcined at 600 ℃ in an air atmosphere for 2 h, at this time, titanium dioxide with nanobelt morphology is obtained. After cooling, the titanium dioxide precursor with nanobelt morphology and selenium powder are placed in a tube furnace together, and the molar ratio of the titanium dioxide precursor with nanobelt morphology to the selenium powder is 1:4. The calcination is carried out at 450 ℃ in a hydrogen atmosphere for 1 h, the heating rate is 2 ℃ / min, and the gas flow rate is 100 mL / min. At this time, the titanium dioxide nanobelt carrier is obtained.

[0027] (2) The titanium dioxide nanobelt carrier and the surfactant CTAB are sequentially added to ethylene glycol to make them uniformly dispersed, and then iridium chloride hydrate is added to form a uniform suspension. The concentration of the titanium dioxide nanobelt carrier in the ethylene glycol is 1 mg / mL, and the molar ratio of the CTAB to the iridium chloride hydrate used is 3:1. The suspension is placed in an argon-protected environment at 160 ℃ for 1 h. After the reaction is completed, it is naturally cooled to room temperature, and the black powder obtained by the reaction is collected, washed repeatedly with ethanol and deionized water, and then dried to obtain the catalyst supported by the titanium dioxide nanobelt carrier.

[0028] From Figure 1 and Figure 2 It can be seen that the sodium titanate precursor and the titanium dioxide nanobelt carrier are successfully prepared, which shows that the process does not change the morphology. From Figure 3It can be seen that the characteristic binding energy peak corresponding to selenium element is detected on the surface of the titanium dioxide nanobelt carrier, indicating that the selenium element is introduced into the titanium dioxide nanobelt carrier after the gas deposition treatment.

[0029] Example 2 The catalyst preparation method of the present example is basically the same as that of Example 1, except that the amount of titanium dioxide in step (1) of Example 1 is changed to 0.1 g.

[0030] Example 3 The catalyst preparation method of the present example is basically the same as that of Example 1, except that the titanium dioxide in step (1) of Example 1 is changed to titanium sesquioxide.

[0031] Example 4 The catalyst preparation method of the present example is basically the same as that of Example 1, except that the concentration of sodium hydroxide solution in step (1) of Example 1 is changed to 5 mol / L.

[0032] Example 5 The catalyst preparation method of the present example is basically the same as that of Example 1, except that the temperature of the hydrothermal reaction in step (1) of Example 1 is changed to 200 ℃.

[0033] Example 6 The catalyst preparation method of the present example is basically the same as that of Example 1, except that the time of the hydrothermal reaction in step (1) of Example 1 is changed to 20 h.

[0034] Example 7 The catalyst preparation method of the present example is basically the same as that of Example 1, except that the concentration of hydrochloric acid solution in step (1) of Example 1 is changed to 0.5 mol / L.

[0035] Example 8 The catalyst preparation method of the present example is basically the same as that of Example 1, except that the concentration of sodium titanate precursor after adding to the hydrochloric acid solution in step (1) of Example 1 is 2 mg / mL.

[0036] Example 9 The catalyst preparation method of the present example is basically the same as that of Example 1, except that the ion exchange time in step (1) of Example 1 is changed to 30 h.

[0037] Example 10 The catalyst preparation method of the present example is basically the same as that of Example 1, except that the calcination atmosphere of the titanate precursor in step (1) of Example 1 is changed from air to oxygen.

[0038] Example 11 The catalyst preparation method of the present example is basically the same as that of Example 1, except that the calcination temperature of the titanate precursor in step (1) of Example 1 is changed to 500 ℃.

[0039] Example 12 The catalyst preparation method of the present example is basically the same as that of Example 1, except that the calcination time of the titanate precursor in step (1) of Example 1 is changed to 3 h.

[0040] Example 13 A PEM electrolytic water anode catalyst, comprising a titanium dioxide nanobelt carrier and a supported noble metal, the noble metal loading being 50wt%. The PEM electrolytic water anode catalyst preparation method, comprising the following steps: (1) 0.2 g of titanium dioxide is mixed with 40 ml of 10 mol / L sodium hydroxide solution, followed by hydrothermal reaction at 185 ℃ for 24 h. After the reaction, a precipitate is obtained, which is washed and dried to obtain a sodium titanate precursor. Then, the sodium titanate precursor is dispersed in a 0.1 mol / L hydrochloric acid solution for ion exchange reaction, ensuring that the concentration of the dispersed sodium titanate precursor is 1 mg / mL, and the ion exchange time is 24 h. After washing with deionized water for 5 times, the titanium dioxide precursor is obtained after drying. The titanium dioxide precursor is placed in a tube furnace and calcined at 600 ℃ in an air atmosphere for 2 h, at which time a titanium dioxide nanobelt carrier with nanobelt morphology is obtained. After cooling, the titanium dioxide nanobelt carrier with nanobelt morphology and sulfur powder are placed together in a tube furnace, and the molar ratio of the titanium dioxide nanobelt carrier with nanobelt morphology to sulfur powder is 1:4. The mixture is calcined at 450 ℃ in a hydrogen atmosphere for 1 h, with a heating rate of 2 ℃ / min and a gas flow rate of 100 mL / min. At this time, a titanium dioxide nanobelt carrier is obtained.

[0041] (2) The titanium dioxide nanobelt carrier and the surfactant CTAB are sequentially added to ethylene glycol to disperse uniformly, followed by the addition of iridium chloride hydrate to form a uniform suspension. The concentration of the titanium dioxide nanobelt carrier in the ethylene glycol is 1 mg / mL, and the molar ratio of the CTAB to the iridium chloride hydrate used is 3:1. The suspension is placed in an argon-protected environment at 160 ℃ for 1 h. After the reaction is completed, it is naturally cooled to room temperature, and the black powder obtained from the reaction is collected, washed repeatedly with ethanol and deionized water, and then dried to obtain a catalyst supported by the titanium dioxide nanobelt carrier.

[0042] Example 14 The catalyst preparation method of the present example is basically the same as that of Example 1, except that the molar ratio of the titanium dioxide precursor with nanobelt morphology to selenium powder in step (1) of Example 1 is changed to 1:1.

[0043] Example 15 The catalyst preparation method of this example is basically the same as that of Example 1, except that the calcination temperature after mixing the nanobelt-shaped titanium dioxide precursor and selenium powder in step (1) of Example 1 is changed to 400 ℃.

[0044] Example 16 The catalyst preparation method of this example is basically the same as that of Example 1, except that the calcination time after mixing the nanobelt-shaped titanium dioxide precursor and selenium powder in step (1) of Example 1 is changed to 1.5 h.

[0045] Example 17 The catalyst preparation method of this example is basically the same as that of Example 1, except that the heating rate of calcination after mixing the nanobelt-shaped titanium dioxide precursor and selenium powder in step (1) of Example 1 is changed to 5 ℃ / min.

[0046] Example 18 The catalyst preparation method of this example is basically the same as that of Example 1, except that the gas flow rate of calcination after mixing the nanobelt-shaped titanium dioxide precursor and selenium powder in step (1) of Example 1 is changed to 200 mL / min.

[0047] Example 19 The catalyst preparation method of this example is basically the same as that of Example 1, except that the concentration of the nanobelt-shaped titanium dioxide carrier in ethylene glycol in step (2) of Example 1 is changed to 5 mg / mL.

[0048] Example 20 The catalyst preparation method of this example is basically the same as that of Example 1, except that the surfactant in step (2) of Example 1 is changed to PVB.

[0049] Example 21 The catalyst preparation method of this example is basically the same as that of Example 1, except that the molar ratio of the surfactant to the chloroiridic acid hydrate in step (2) of Example 1 is changed to 1:1.

[0050] Example 22 The catalyst preparation method of this example is basically the same as that of Example 1, except that the soluble noble metal precursor chloroiridic acid hydrate in step (2) of Example 1 is changed to a mixture of chloroiridic acid hydrate and ruthenium trichloride with a molar ratio of 1:1.

[0051] Example 23 The catalyst preparation method of this example is basically the same as that of Example 1, except that the reaction temperature of the suspension in step (2) of Example 1 is changed from 160 ℃ to 180 ℃.

[0052] Example 24 The catalyst preparation method of this example is basically the same as that of Example 1, except that the reaction time of the suspension in step (2) of Example 1 is changed from 1 h to 3 h.

[0053] Comparative Example 1 This comparative example provides a commercial iridium black catalyst (Premetek, USA, iridium black, 98.0-100% iridium).

[0054] Comparative Example 2 This comparative example provides a commercial iridium oxide catalyst (Ningbo Zhongke Kexin New Energy Technology Co., Ltd., iridium oxide > 95 wt.%).

[0055] Comparative Example 3 A commercial titanium dioxide (Shanghai Maikelin Technology Co., Ltd., 99%, titanium dioxide) and a surfactant CTAB were sequentially added into ethylene glycol to make them uniformly dispersed, and then iridium chlorohydrate was added to form a uniform suspension, wherein the concentration of the titanium dioxide nanobelt carrier in ethylene glycol was 1 mg / mL, and the molar ratio of CTAB to iridium chlorohydrate used was 3:1. The suspension was placed in an argon-protected environment at 160 ℃ for 1 h. After the reaction was completed, it was naturally cooled to room temperature, and the black powder obtained by the reaction was washed repeatedly with ethanol and deionized water and then dried to obtain a catalyst supported by a titanium dioxide nanobelt carrier.

[0056] Comparative Example 4 A PEM electrolytic water anode catalyst includes a titanium dioxide nanobelt carrier and a supported noble metal, and the noble metal loading is 50 wt%. The preparation method of the PEM electrolytic water anode catalyst includes the following steps: The preparation method includes the following steps: (1) 0.2 g of titanium dioxide was mixed with 40 ml of 10 mol / L sodium hydroxide solution, and then a hydrothermal reaction was carried out at 185 ℃ for 24 h. After the reaction, the precipitate was washed and dried to obtain a sodium titanate precursor. Then, the sodium titanate precursor was dispersed in a 0.1 mol / L hydrochloric acid solution for ion exchange reaction, ensuring that the concentration of the dispersed sodium titanate precursor was 1 mg / mL, and the ion exchange time was 24 h. After washing with deionized water for 5 times, the dried product was a titanate precursor. The titanate precursor was placed in a tube furnace and calcined at 600 ℃ in an air atmosphere for 2 h, at which time a titanium dioxide precursor with nanobelt morphology was obtained.

[0057] (2) The titanium dioxide precursor and the surfactant CTAB were added into ethylene glycol in sequence, and were uniformly dispersed, then the iridium chloride hydrate was added, and a uniform suspension was formed, wherein the concentration of the titanium dioxide precursor in the ethylene glycol was 1 mg / mL, and the molar ratio of the CTAB to the iridium chloride hydrate was 3:1. The suspension was placed in an argon-protected environment at 160°C for 1 h. After the reaction was completed, the reaction product was naturally cooled to room temperature, and the black powder was collected, washed with ethanol and deionized water, and dried to obtain the catalyst supported by the titanium dioxide nanobelt carrier.

[0058] The catalysts prepared in Examples 1-20 and Comparative Examples 1-4 were subjected to electrocatalytic OER performance testing, and the specific process was as follows: 2 mg of the catalyst was added to a mixed solution of 300 μL of anhydrous ethanol and 100 μL of ultrapure water, 5 μL of a Nafion solution was added, and a uniform catalyst ink was obtained after ultrasonic treatment. A certain amount of the catalyst ink was drop-casted on the surface of a 5 mm gold electrode as a working electrode for testing, and the active component loading was 0.12 mg cm -2 , and a 0.5 M sulfuric acid solution was used as an electrolyte, and the test was performed in a three-electrode system composed of a platinum sheet and a silver / silver chloride. During the test, the rotation speed of the working electrode was 1600 rpm.

[0059] According to the above test method, the oxygen evolution reaction overpotential results of the catalysts prepared in Examples 1-24 and Comparative Examples 1, 3 and 4 were obtained by catalytic performance testing, as shown in Table 1.

[0060] Table 1 From Figure 4 , Figure 5 , it can be seen that, according to the performance test results of Examples 1 and 13 and Comparative Examples 1, 3 and 4, an electronic interaction occurs between the titanium dioxide nanobelt carrier and the iridium nanoparticles loaded on the surface thereof. In addition, the doping of the sulfur family element improves the electronic transmission efficiency and electrical conductivity of the carrier, and also improves the corrosion resistance, thereby regulating the binding energy of the iridium nanoparticle surface and the reaction intermediates, and ultimately improving the OER activity of the iridium nanoparticles, so that the OER overpotentials of them are different.

[0061] In combination with all the examples, it should be understood that, without deviating from the technical concept of the present application, the person skilled in the art can adjust the amount of titanium source, the concentration of alkali solution, the hydrothermal reaction temperature or time, the ion exchange conditions, and the calcination temperature and atmosphere to regulate the physicochemical properties of the titanium dioxide nanobelt. The above regulation can realize the introduction of the subsequent doping elements and the effective loading of the noble metal, so as to obtain a catalyst carrier suitable for PEM water electrolysis anodes.

[0062] In view of the fact that the stability of the ruthenium-based OER catalyst under acidic conditions is weaker than that of the iridium-based material, the titanium dioxide nanobelt carrier loaded iridium catalyst prepared in Example 1 and the comparative example 2 were subjected to performance testing in a PEM electrolyzer, the cathode used 60% platinum carbon commercial catalyst for reaction, and the anode used the titanium dioxide nanobelt carrier loaded iridium catalyst prepared in Example 1 or the comparative example 2 for reaction, the two kinds of catalysts were respectively prepared into catalyst ink and ultrasonically treated for 1 h under constant temperature conditions to ensure uniformity of the catalyst ink, then the two kinds of catalysts were respectively sprayed on both sides of a proton exchange membrane to obtain a membrane electrode, and the membrane electrode was assembled into a PEM electrolyzer. The iridium loading amount of the membrane electrode prepared in Example 1 of the present application was 0.3 mg cm -2 The iridium loading amount of the membrane electrode prepared in comparative example 2 was 1 mg cm -2 .

[0063] From Figure 6 it can be known that the electrolysis voltage of the membrane electrode prepared from the titanium dioxide nanobelt carrier loaded iridium catalyst in Example 1 of the present application reached 1.66 V under a current density of 1 A cm -2 .

[0064] The performance testing results of the titanium dioxide nanobelt carrier loaded iridium catalyst prepared in Example 1 in a PEM electrolyzer are shown in Figure 7 , which can be stably operated for 1000 h under the current density, indicating that the supported catalyst can exert excellent performance when applied in an actual PEM electrolyzer.

[0065] The above only describes the preferred embodiments of the present application and is not intended to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing titanium dioxide nanoribbon carriers, characterized in that, Includes the following steps: (1) Titanium dioxide nanoribbons were prepared by hydrothermal method; (2) Titanium dioxide nanoribbons and doped element precursors are placed in a tube furnace and sulfur or selenium is doped by vapor deposition to prepare titanium dioxide nanoribbon carriers.

2. The method for preparing titanium dioxide nanoribbon carriers according to claim 1, characterized in that, The steps for preparing titanium dioxide nanoribbons by the hydrothermal method are as follows: adding a titanium source to an alkaline solution to carry out a hydrothermal reaction to obtain a titanate precursor; dispersing the titanate precursor in an acid solution to carry out ion exchange to obtain a titanic acid precursor; and calcining the titanic acid precursor to obtain a titanium dioxide precursor with a nanoribbon morphology.

3. The method for preparing titanium dioxide nanoribbon carriers according to claim 2, characterized in that, The titanium source is titanium dioxide or titanium trioxide; the alkaline solution is a sodium hydroxide and / or potassium hydroxide solution with a concentration of 5-10 mol / L; the concentration of the titanium source in the alkaline solution is 1-5 mg / mL; the hydrothermal reaction temperature is 160 ℃-200 ℃, and the time is 12-24 h.

4. The method for preparing titanium dioxide nanoribbon carriers according to claim 3, characterized in that, The acid solution is a hydrochloric acid and / or nitric acid solution with a concentration of 0.1-1 mol / L; the concentration of the titanate precursor in the acid solution is 0.5-5 mg / mL; and the ion exchange time is 12-36 h.

5. The method for preparing titanium dioxide nanoribbon carriers according to claim 4, characterized in that, The calcination temperature is 400-600 ℃, and the time is 1.5-3.5 h.

6. The method for preparing titanium dioxide nanoribbon carriers according to any one of claims 1-5, characterized in that, The precursor for the doping element is sulfur powder or selenium powder; the molar ratio of the titanium dioxide precursor to the precursor for the doping element is 1:1-8; the vapor deposition method is carried out in an atmosphere of argon or a hydrogen-argon mixture, with a gas flow rate of 50-200 mL / min, a calcination temperature of 400-600 ℃, a time of 1.5-3.5 h, and a heating rate of 1-10 ℃ / min.

7. A method for preparing a PEM anode catalyst for water electrolysis, characterized in that, The process includes the following steps: dispersing and dissolving the titanium dioxide nanoribbon support, surfactant, and soluble noble metal precursor prepared by the method of any one of claims 1-6 in a solvent, and then reacting them to obtain the PEM water electrolysis anode catalyst.

8. The method for preparing the PEM electrolysis water anode catalyst according to claim 7, characterized in that, The surfactant is one or more of hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, or polyvinyl butyral; the soluble noble metal precursor is one or more of iridium trichloride hydrate, iridium tetrachloride, iridium chlorohydrate, ammonium hexachloroiridate, ruthenium trichloride, or ammonium ruthenium chlorohydrate; the solvent is one or more of water, anhydrous ethanol, isopropanol, or ethylene glycol.

9. The method for preparing the PEM anode catalyst for water electrolysis according to claim 8, characterized in that, The concentration of titanium dioxide nanoribbon carrier in the solvent is 1-5 mg / mL; the molar ratio of the soluble noble metal precursor to the surfactant is 1:1-4; the reaction temperature is 150-190 ℃, and the reaction time is 1-3 h.

10. The PEM anode catalyst for water electrolysis prepared by the method according to any one of claims 7-9, characterized in that, It includes titanium dioxide nanoribbons as a carrier and a loaded noble metal, wherein the loading of the noble metal is 5-50 wt%.

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