Iridium catalyst loaded on amorphous carrier as well as preparation method and application thereof

Abstract

The invention discloses an amorphous carrier supported iridium catalyst as well as a preparation method and application thereof, and belongs to the technical field of catalysts. According to the preparation method, firstly, a precursor containing a zirconium element is prepared through a hydrothermal method, an amorphous zirconium oxide catalyst loaded with Ir clusters is prepared through a second-step hydrothermal method, the confinement effect of the amorphous surface of the carrier ensures that the size of the Ir nanoclusters loaded on the surface of the carrier is small, and the utilization rate of precious metal is increased; and due to the enhanced carrier-metal effect, the catalyst shows good activity and stability in proton exchange membrane water electrolysis hydrogen production equipment. When the anode catalyst is used for carrying out activity and stability tests in a three-electrode system, the supported catalyst not only shows relatively high activity, but also keeps relatively good stability in a long-time test process. Therefore, the amorphous zirconium oxide loaded Ir catalyst has the advantages of high metal utilization rate and excellent activity and stability in an oxygen evolution test process.

Description

Technical Field

[0001] The invention belongs to the technical field of catalysts, and specifically relates to an amorphous carrier-loaded iridium catalyst and a preparation method and application thereof. Background Art

[0002] The proposal of the dual carbon goals of "carbon peak" and "carbon neutrality" has greatly promoted the rapid development of hydrogen energy. Proton exchange membrane water electrolysis (PEMWE) technology has great application prospects in the field of green hydrogen production due to its rapid response capability to fluctuating and intermittent renewable energy (such as solar and wind power) electricity. However, the PEMWE anode is in a strongly acidic, high oxidation potential environment, and the oxygen evolution reaction (OER) reaction energy barrier is high, requiring the use of a large amount of precious metal iridium (Ir)-based catalysts, but Ir reserves in the earth's crust are scarce and the cost is high, which limits the application of PEMWE in actual production. Therefore, the development of anode oxygen evolution reaction catalysts with low Ir loading is crucial to reducing the technical cost of PEMWE and realizing its large-scale application.

[0003] Using transition metal oxides (such as TiO2, Nb2O5, ZrO2, etc.) as carriers to load Ir is an effective way to reduce the amount of precious metals used, and there have been many studies. For example, Hyun-Seok Cho's team developed an IrO loaded on Zr2ON2. x Nanoparticle catalyst, at 0.4 mg Ir cm -2 The catalysts exhibited superior membrane electrode performance to commercial catalysts at loadings of 1000 nm. (Lee, C.; Shin, K.; Park, Y.; Yun, Y.H.; Doo, G.; Jung, GH; Kim, M.; Cho, W.C.; Kim, CH; Lee, H.M.; Kim, HY; Lee, S.; Henkelman, G.; Cho, HS, Catalyst-Support Interactions in Zr2ON2-Supported IrO xElectrocatalysts to Break the Trade-Off Relationship Between the Activity and Stability in the Acidic Oxygen Evolution Reaction. Advanced Functional Materials 2023, 33 (25).). ShuangMaAndersen's team used a microwave-assisted polyol synthesis method to prepare metal Ir nanoparticles (Ir-NPs) supported by antimony-doped tin oxide (ATO), achieving efficient dispersion of Ir on the carrier, and proved that the ATO carrier can effectively electronically modulate the Ir active sites during the reaction, achieving an electron-rich state of the Ir site, thereby inhibiting the oxidative dissolution of Ir. (Ali Khan, I.; Morgen, P.; Gyergyek, S.; Sharma, R.; Ma Andersen, S., Reduced valence state of iridium supported onantimony doped tin oxide as a highly active and robust oxygen evolution reaction electrocatalyst for proton exchange membrane-based electrolysis. Applied Surface Science 2024, 646.) Xu et al. formed a Mn-O-Ir coordination structure through a hydrothermal-redox reaction, which drove the strong anchoring of Ir species on the MnO2 substrate. The significant electronegativity difference between Mn and Ir atoms promoted the redistribution of electrons between the Mn-O-Ir coordination structure, thereby achieving the stability of the catalyst in acidic OER. (Weng, Y.; Wang, K.; Li, S.; Wang, Y.; Lei, L.; Zhuang, L.; Xu, Z., High-Valence-Manganese Driven Strong Anchoring of Iridium Species for RobustAcidic WaterOxidation. Adv Sci (Weinh) 2023, 10 (8), e2205920.)

[0004] Although the above supported catalysts can improve the dispersibility of Ir and reduce the amount of precious metals to a certain extent, the electron transfer between the carrier and the active center Ir is limited, and the weak carrier-metal interaction (MSI) is usually difficult to inhibit the aggregation and oxidative dissolution of Ir species under high potential and long-term test conditions, resulting in catalyst performance loss. In contrast, amorphous metal oxides usually have abundant metal unsaturated bonds, and the unsaturated electronic configuration promotes more flexible orbital coupling, accelerates the charge transfer between it and the active center, and further enhances the carrier-metal interaction. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] Aiming at the problem that the interaction between the metal oxide carrier and the loaded Ir in the anode-loaded catalyst of the prior art proton exchange membrane water electrolysis (PEMWE) is weak, and the metal-carrier interaction cannot be effectively utilized to improve the intrinsic activity and stability, the amorphous zirconia carrier-loaded Ir catalyst provided by the present invention can reduce the Ir particle size and thus increase the utilization rate of the precious metal due to the substrate confinement effect unique to the amorphous carrier, and the amorphous configuration can induce and strengthen MSI, thereby regulating the electronic structure of Ir, increasing the electron density of the Ir site, inhibiting the over-oxidation of Ir in the catalytic process, effectively improving the utilization rate of the surface catalytic active center and reducing the amount of precious metal. The prepared amorphous carrier-loaded Ir catalyst exhibits good catalytic activity and catalytic stability in the electrolytic cell equipment, effectively solving the above problems.

[0007] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0008] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing an amorphous carrier-supported iridium catalyst.

[0009] In order to solve the above technical problems, the present invention provides the following technical solutions, including:

[0010] The metal zirconium salt and the metal strontium salt are mixed to undergo a hydrothermal reaction to obtain a precursor containing zirconium element S rZrO3;

[0011] The precursor SrZrO3 is washed and dried and then stirred with Ir salt in an aqueous solution to obtain a mixed solution;

[0012] The mixed solution is subjected to a secondary hydrothermal reaction to obtain an amorphous carrier-supported iridium catalyst.

[0013] As a preferred embodiment of the method for preparing the amorphous carrier-loaded iridium catalyst of the present invention, the metal zirconium salt includes one or more of zirconium oxychloride octahydrate, zirconium nitrate, and calcium chloride; the metal strontium salt includes one or more of strontium nitrate, strontium chloride, and strontium acetate.

[0014] As a preferred embodiment of the method for preparing the amorphous carrier-supported iridium catalyst of the present invention, the molar ratio of the metal zirconium salt to the metal strontium salt is 0.5 to 1.5:1.

[0015] As a preferred embodiment of the method for preparing the amorphous carrier-supported iridium catalyst of the present invention, the primary hydrothermal reaction comprises the following steps: the hydrothermal temperature is 110 to 200°C, the hydrothermal time is 12 to 36 hours, and the heating rate is 3 to 5°C / min.

[0016] As a preferred embodiment of the preparation method of the amorphous carrier-supported iridium catalyst of the present invention, the Ir salt includes one or more of chloroiridic acid, iridium chloride, iridium acetylacetonate, iridium acetate, potassium chloroiridate, sodium chloroiridate, iridium oxide, strontium iridate, barium iridate, lithium iridate, potassium iridate or praseodymium iridate.

[0017] As a preferred embodiment of the method for preparing the amorphous carrier-supported iridium catalyst of the present invention, the molar ratio of the Zr element in the precursor SrZrO3 to the Ir element in the Ir salt is 0.4-4:1.

[0018] As a preferred embodiment of the method for preparing the amorphous carrier-supported iridium catalyst of the present invention, the stirring time is 5 to 24 hours.

[0019] As a preferred embodiment of the method for preparing the amorphous carrier-loaded iridium catalyst of the present invention, the secondary hydrothermal reaction comprises the following steps: the hydrothermal temperature is 120 to 200°C, the hydrothermal time is 12 to 36 hours, and the heating rate is 3 to 5°C / min.

[0020] Another object of the present invention is to overcome the deficiencies in the prior art and provide an amorphous carrier-supported iridium catalyst, wherein the amorphous carrier-supported iridium catalyst uses amorphous zirconium oxide as a carrier on which Ir clusters are supported;

[0021] Wherein, the mass ratio of the Ir cluster to the amorphous zirconia carrier is 0.2-4:1.

[0022] The third purpose of the present invention is to overcome the deficiencies in the prior art and provide an application of an amorphous carrier-supported iridium catalyst in a proton exchange membrane water electrolysis reaction.

[0023] The three-electrode system assembled with the amorphous carrier supporting the iridium catalyst has a catalyst loading of 0.5 mg / cm 2 Under the condition, it can reach 10mA / cm 2 The current density is <371mV;

[0024] At 10mA / cm 2 The stable operation time at the current density is >150h and the voltage decay is <80mV.

[0025] Beneficial effects of the present invention:

[0026] (1) The preparation method of the amorphous zirconium oxide-loaded Ir proton exchange membrane water electrolysis anode catalyst provided by the present invention realizes the loading of Ir clusters on the amorphous carrier through a two-step hydrothermal process. The synthesis method is simple and convenient, and the target catalyst can be obtained without calcination and ventilation, and no toxic or harmful gases are generated during the reaction. The entire reaction process is safe, low-energy-consuming and environmentally friendly.

[0027] (2) The inhibitory effect of the amorphous carrier on the growth of the Ir loading layer is conducive to the formation of a supported catalyst with smaller Ir nanoclusters. The Ir clusters in the prepared catalyst are evenly distributed and have smaller particle sizes, ensuring a higher utilization rate of precious metals. In addition, the unique amorphous carrier enhances the interaction between the Ir clusters and ZrO x Electronic interactions between carriers.

[0028] (3) The catalyst prepared by the present invention exhibits good catalytic activity and stability. Compared with Ir loaded on a high-crystallinity commercial zirconia carrier, its overpotential is reduced by about 100 mV. With the same Ir loading, the mass activity at 1.6 V is increased by about 2.5 times.

[0029] (4) At 10 mA / cm 2 The stability test was carried out under a current density of 400 ℃ and 800 ℃. The performance of the amorphous zirconia-loaded Ir catalyst provided by the present invention did not decay significantly within 500 h, while the potential of the Ir catalyst loaded on a high-crystallinity commercial zirconia carrier increased rapidly within 100 h, indicating that the unique substrate confinement effect of the amorphous carrier and the enhanced MSI between the amorphous carrier and the loaded Ir clusters effectively achieved a synergistic improvement in catalyst activity and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0031] Figure 1Transmission electron microscope image and selected area electron diffraction image of the amorphous zirconium oxide carrier loaded with Ir proton exchange membrane water electrolysis anode catalyst prepared in Example 1 of the present invention;

[0032] Figure 2 The transmission electron microscope element distribution scanning result of the amorphous zirconium oxide carrier loaded with Ir proton exchange membrane water electrolysis anode catalyst prepared in Example 1 of the present invention;

[0033] Figure 3 The X-ray diffraction spectrum of the Ir proton exchange membrane water electrolysis anode catalyst supported by the amorphous zirconium oxide carrier prepared in Example 1 of the present invention;

[0034] Figure 4 The amorphous zirconium oxide carrier-loaded Ir proton exchange membrane water electrolysis anode catalyst prepared in Example 1 of the present invention and the highly crystalline zirconium oxide-loaded Ir catalyst and iridium oxide catalyst prepared in the same manner were heated to 0.5 mol L -1 Linear sweep voltammetry curve in sulfuric acid solution (left), Tafel slope curve (right);

[0035] Figure 5 The amorphous zirconium oxide carrier loaded with Ir proton exchange membrane water electrolysis anode catalyst prepared in Example 1 of the present invention was used in 0.5 mol L -1 Chemical impedance spectroscopy in sulfuric acid solution;

[0036] Figure 6 The amorphous zirconium oxide carrier loaded with Ir proton exchange membrane water electrolysis anode catalyst prepared in Example 1 of the present invention and the highly crystalline zirconium oxide loaded with Ir catalyst and iridium oxide catalyst prepared in the same manner were used to prepare the catalyst under 10 mA cm -2 Chronopotentiometry curves under current density and the dissolution curve of precious metal Ir during the 500h test (upper right). DETAILED DESCRIPTION

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0038] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0039] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0040] Unless otherwise specified, the raw materials used in the present invention are all common commercially available analytically pure chemicals.

[0041] Iridium chloride hydrate, chemical formula is IrCl3 xH2O, Ir content ≥58%.

[0042] Example 1

[0043] This embodiment provides a method for preparing an amorphous carrier-supported iridium catalyst, specifically:

[0044] Weigh 0.529g of strontium nitrate into a polytetrafluoroethylene liner, add 20mL of KOH with a concentration of about 10M and stir evenly, then add 0.741g of zirconium oxychloride octahydrate (i.e., the molar ratio of metal zirconium salt to metal strontium salt is 0.92:1), mix and stir the above raw materials for about 12 hours, screw the stainless steel outer liner and put it into an oven, hydrotherm at 180℃ for 24 hours, and the heating rate is 4℃ / min. After the reaction is completed, centrifuge and wash three times with deionized water, place in a 55℃ oven to dry, and obtain a white precursor solid SrZrO3 containing zirconium and strontium elements.

[0045] Dissolve 200 mg of the precursor SrZrO3 containing zirconium and strontium elements and 263 mg of hydrated iridium chloride in 20 ml of deionized water (the molar ratio of Zr element in the precursor SrZrO3 to Ir element in the Ir salt is 1:1), ultrasonically disperse for 1 hour, stir for about 12 hours, transfer the mixed solution to the polytetrafluoroethylene liner, screw the stainless steel liner and put it in an oven, hydrothermally heat at 150°C for 12 hours, and the heating rate is 4°C / min. After the reaction is completed, wash it three times with deionized water and dry it in an oven at 55°C to obtain an amorphous zirconium oxide supported catalyst loaded with Ir nanoclusters.

[0046] The amorphous zirconium oxide carrier-supported Ir proton exchange membrane water electrolysis anode catalyst of Example 1 was characterized by transmission electron microscopy. The results are as follows: Figure 1 As shown, it can be seen that the Ir nanoclusters in the obtained catalyst are dispersed on the surface of the amorphous zirconia support.

[0047] The element mapping analysis of the amorphous zirconium oxide carrier-supported Ir proton exchange membrane water electrolysis anode catalyst in Example 1 was performed, and the results were as follows: Figure 2 As shown, the catalyst contains Zr, Ir, and O elements at the same time, confirming the synthesis of the amorphous support and the effective loading of Ir.

[0048] The amorphous zirconium oxide carrier of Example 1 was characterized by X-ray diffraction. The results are as follows: Figure 3 As shown, the prepared carrier has an amorphous structure.

[0049] The amorphous zirconium oxide carrier-supported Ir proton exchange membrane water electrolysis anode catalyst of Example 1 was characterized by X-ray diffraction. The results are as follows: Figure 3 As shown, only the X-ray diffraction peak corresponding to elemental Ir was observed for the prepared supported catalyst, which proved that Ir was successfully loaded and the support still maintained an amorphous structure.

[0050] The performance of the amorphous zirconium oxide carrier loaded with Ir proton exchange membrane water electrolysis anode catalyst in the three-electrode system was tested. The results are as follows: Figure 4 , Figure 5 The three-electrode system assembled with this catalyst has a catalyst loading of 0.5 mg / cm 2 Under the condition, it can reach 10mA / cm 2 The current density required was only 264 mV, and the catalyst showed high metal utilization and good catalytic activity.

[0051] The stability test of the amorphous zirconium oxide carrier loaded with Ir proton exchange membrane water electrolysis anode catalyst in the three-electrode system was carried out. The results are as follows: Figure 6 The catalyst was added dropwise onto carbon paper at a catalyst loading of 2 mg / cm 2 Under the condition of 10mA / cm 2 The catalyst can operate stably for more than 500 h at a current density of , and the voltage decay is about 40 mV, indicating that the catalyst exhibits good catalytic stability in the electrolytic cell system.

[0052] Example 2

[0053] The difference between this embodiment and embodiment 1 is that the molar ratio of the Zr element in the precursor SrZrO3 to the Ir element in the Ir salt is adjusted to 1.5:1, and the rest of the preparation process is the same as that in embodiment 1, to obtain an amorphous zirconium oxide supported catalyst loaded with Ir nanoclusters.

[0054] Example 3

[0055] The difference between this embodiment and embodiment 1 is that the molar ratio of the Zr element in the precursor SrZrO3 to the Ir element in the Ir salt is adjusted to 2:1, and the rest of the preparation process is the same as that of embodiment 1, and an amorphous zirconium oxide supported catalyst loaded with Ir nanoclusters is obtained.

[0056] Example 4

[0057] The difference between this embodiment and embodiment 1 is that the molar ratio of the Zr element in the precursor SrZrO3 to the Ir element in the Ir salt is adjusted to 0.4:1, and the rest of the preparation process is the same as that in embodiment 1, to obtain an amorphous zirconia supported catalyst loaded with Ir nanoclusters.

[0058] Example 5

[0059] The difference between this embodiment and embodiment 1 is that the molar ratio of the Zr element in the precursor SrZrO3 to the Ir element in the Ir salt is adjusted to 0.25:1, and the rest of the preparation process is the same as that of embodiment 1, and an amorphous zirconium oxide supported catalyst loaded with Ir nanoclusters is obtained.

[0060] Comparative Example 1

[0061] The difference between this comparative example and Example 1 is that the molar ratio of the Zr element in the precursor SrZrO3 to the Ir element in the Ir salt is adjusted to 6:1, and the rest of the preparation process is the same as that in Example 1, to obtain an amorphous zirconia supported catalyst loaded with Ir nanoclusters.

[0062] The performance of the material prepared in the above embodiment was tested, and the comparison results with those in Example 1 are shown in Table 1.

[0063] Table 1

[0064] Overpotential Stable operation time Voltage decay Example 1 264mV >500h 40mV Example 2 281mV <400h 50mV Example 3 312mV <200h 60mV Example 4 371mV <200h 70mV Example 5 341mV <200h 70mV Comparative Example 1 414mV <10h 100mV

[0065] As can be seen from the above table, adjusting the molar ratio of Zr element in the precursor SrZrO3 to Ir element in the Ir salt has a significant effect on the performance of the amorphous zirconia supported catalyst loaded with Ir nanoclusters. This is because after the hydrothermal reaction, the iridium clusters loaded on the amorphous carrier agglomerate in large quantities, resulting in a reduction in the number of active sites, reducing the intrinsic activity of the precious metal Ir, resulting in poor conductivity of the metal oxide carrier, and inhibiting the expression of catalyst activity. According to the results in the above table, the best technical effect can be obtained when the molar ratio of Zr element in the precursor SrZrO3 to Ir element in the Ir salt is 1:1.

[0066] Example 6

[0067] The difference between this embodiment and embodiment 1 is that the temperature of the secondary hydrothermal reaction is adjusted to 110° C., and the rest of the preparation process is the same as that of embodiment 1, to prepare an amorphous zirconia supported catalyst loaded with Ir nanoclusters.

[0068] Example 7

[0069] The difference between this embodiment and embodiment 1 is that the temperature of the secondary hydrothermal reaction is adjusted to 130° C., and the rest of the preparation process is the same as that of embodiment 1, to prepare an amorphous zirconia supported catalyst loaded with Ir nanoclusters.

[0070] Example 8

[0071] The difference between this embodiment and embodiment 1 is that the temperature of the secondary hydrothermal reaction is adjusted to 170° C., and the rest of the preparation process is the same as that of embodiment 1, to prepare an amorphous zirconia supported catalyst loaded with Ir nanoclusters.

[0072] Example 9

[0073] The difference between this embodiment and embodiment 1 is that the temperature of the secondary hydrothermal reaction is adjusted to 200° C., and the rest of the preparation process is the same as that of embodiment 1, to prepare an amorphous zirconia supported catalyst loaded with Ir nanoclusters.

[0074] The performance of the material prepared in the above embodiment was tested, and the comparison results with those in Example 1 are shown in Table 2.

[0075] Table 2

[0076] Overpotential Stable operation time Voltage decay Example 1 264mV >500h 40mV Example 6 304mV <300h 80mV Example 7 281mV <200h 50mV Example 8 290mV <300h 50mV Example 9 284mV - -

[0077] Note: “-” means no data.

[0078] It can be seen from the above table that adjusting the temperature of the second hydrothermal reaction has a significant effect on the performance of the amorphous zirconia supported catalyst loaded with Ir nanoclusters. This is because when the reaction temperature is low, the Sr element in the precursor SrZrO3 is difficult to dissolve, which inhibits the formation of the amorphous zirconia carrier; when the reaction temperature is high, the formed amorphous zirconia supported iridium catalyst degrades under high temperature and high pressure reaction conditions, and it is ultimately difficult to obtain the target catalyst of amorphous zirconia supported iridium. According to the results in the above table, the best technical effect can be obtained when the second hydrothermal reaction temperature in the present invention is 150°C.

[0079] Example 10

[0080] The difference between this embodiment and embodiment 1 is that the iridium salt is adjusted to potassium hexachloroiridate, and the rest of the preparation process is the same as that of embodiment 1, and an amorphous zirconium oxide supported catalyst loaded with Ir nanoclusters is prepared.

[0081] The performance of the material prepared in the above embodiment was tested, and the comparison results with those in Example 1 are shown in Table 2.

[0082] Table 2

[0083] Overpotential Stable operation time Voltage decay Example 1 264mV >500h 40mV Example 10 304mV - -

[0084] Note: “-” means no data.

[0085] As can be seen from the above table, when the iridium salt is hydrated iridium trichloride, the solution is highly acidic. Under this condition, the precursor SrZrO3 dissolves in situ, and the leaching of Sr element induces the amorphous ZrO x Formation of carrier; When the iridium salt is potassium hexachloroiridate, the solution is neutral. Even if hydrochloric acid is added to adjust the pH, the formation of amorphous carrier is more difficult. The chloride ion content is higher and it is easier to form coordination with Ir, which inhibits the Ir-ZrO x Therefore, adjusting the type of iridium salt has a significant effect on the performance of the amorphous zirconium oxide supported catalyst loaded with Ir nanoclusters, and the best technical effect can be obtained when the iridium salt is hydrated iridium chloride in the present invention.

[0086] Comparative Example 2

[0087] Weigh 109 mg of commercial zirconium dioxide and 132 mg of hydrated iridium chloride and dissolve them in 20 ml of deionized water, disperse them ultrasonically for 1 hour, stir them at room temperature for about 12 hours, transfer the mixed solution to the polytetrafluoroethylene liner, screw the stainless steel liner and put it in an oven, hydrothermally heat it at 150°C for 12 hours, and the heating rate is about 4°C / min. After the reaction is completed, wash it three times with deionized water and dry it in an oven at 55°C to obtain a highly crystalline zirconium oxide supported catalyst loaded with Ir nanoclusters.

[0088] The activity and stability of the three-electrode system of the Ir proton exchange membrane water electrolysis anode catalyst supported by the high crystallinity zirconium oxide carrier of Comparative Example 1 were tested. The results are as follows Figure 4 As shown, at 10 mA / cm 2 The overpotential at the current density was 365 mV. The catalyst was added dropwise onto carbon paper at a catalyst loading of 2 mg / cm 2 Under the conditions of 10 mA / cm 2 The stability test was carried out under the current density, and its performance decayed rapidly within 100 hours. Compared with Example 1, both the activity and stability were greatly reduced.

[0089] Comparative Example 3

[0090] Weigh 109 mg of commercial zirconium dioxide and 263 mg of hydrated iridium chloride and dissolve them in 20 ml of deionized water, disperse them ultrasonically for 1 hour, stir them at room temperature for about 5 hours, transfer the mixed solution to the polytetrafluoroethylene liner, screw the stainless steel liner and put it in an oven, hydroheat it at 120°C for 12 hours, and the heating rate is about 4°C / min. After the reaction is completed, wash it three times with deionized water and dry it in an oven at 55°C to obtain a highly crystalline zirconium oxide supported catalyst loaded with Ir nanoclusters.

[0091] The activity and stability of the three-electrode system of the Ir proton exchange membrane water electrolysis anode catalyst loaded with a high crystallinity zirconia carrier in Comparative Example 2 were tested, and its overpotential at a current density of 10 mA / cm was 314 mV. The catalyst was also tested for stability at a current density of 10 mA / cm, and its performance decayed rapidly within 100 h, similar to Example 6. Compared with Example 1, both the activity and stability were greatly reduced.

[0092] Comparative Example 4

[0093] Weigh 109 mg of commercial zirconium dioxide and 89 mg of hydrated iridium chloride and dissolve them in 20 ml of deionized water, disperse them ultrasonically for 1 hour, stir them at room temperature for about 10 hours, transfer the mixed solution to the polytetrafluoroethylene liner, screw the stainless steel liner and put it in an oven, hydroheat it at 170°C for 12 hours, and the heating rate is about 4°C / min. After the reaction is completed, wash it three times with deionized water and dry it in an oven at 55°C to obtain a highly crystalline zirconium oxide supported catalyst loaded with Ir nanoclusters.

[0094] The activity and stability of the three-electrode system of the high-crystallinity zirconium oxide carrier-loaded Ir proton exchange membrane water electrolysis anode catalyst of Comparative Example 3 were tested, and the overpotential at a current density of 10 mA / cm was 395 mV. The catalyst was also tested for stability at a current density of 10 mA / cm. Its performance decayed rapidly within 100 h. Its performance decayed rapidly within 100 h. Compared with Example 1, both the activity and stability were greatly reduced.

[0095] The performance of the material obtained in the above comparative example was tested, and the comparison results with those of Example 1 are shown in Table 3.

[0096] Table 3

[0097] Overpotential Stable operation time Voltage decay Example 1 264mV ＞500h 40mV Comparative Example 2 365mV ＜150h 30mV Comparative Example 3 314mV ＜150h 30mV Comparative Example 4 395mV ＜150h 30mV

[0098] In summary, in view of the technical problems of low utilization rate of precious metals, poor activity and stability of anode catalysts for proton exchange membrane water electrolysis in the prior art, the present invention provides an amorphous zirconium oxide carrier-loaded Ir catalyst, a preparation method thereof and its application in a three-electrode system, which belongs to the field of catalyst and its preparation technology. Specifically, it includes a zirconium oxide carrier-loaded Ir nanocluster catalyst with an amorphous configuration. The present invention first prepares a precursor containing zirconium elements by a hydrothermal method, and prepares an amorphous zirconium oxide catalyst loaded with Ir clusters by a second hydrothermal method. The confinement effect of the amorphous surface of the carrier ensures that the Ir nanoclusters loaded on the surface of the carrier are small in size, which improves the utilization rate of precious metals, and the enhanced carrier-metal effect makes the catalyst show good activity and stability in the proton exchange membrane water electrolysis hydrogen production equipment. Transmission electron microscopy characterization and X-ray diffraction spectrum show that the carrier presents an amorphous structure. When the activity and stability test of the anode catalyst in a three-electrode system is carried out, the supported catalyst not only shows high activity, but also maintains good stability during long-term testing. Therefore, the amorphous zirconia-loaded Ir catalyst has the advantages of high metal utilization and excellent activity and stability during the oxygen evolution test.

[0099] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for preparing an amorphous carrier-supported iridium catalyst, characterized in that: include, The metal zirconium salt and the metal strontium salt are mixed to undergo a hydrothermal reaction to obtain a precursor containing zirconium element Sr ZrO3; The precursor SrZrO3 is washed, dried, and stirred with Ir salt in an aqueous solution to obtain a mixed solution; The mixed solution is subjected to a secondary hydrothermal reaction to obtain an amorphous carrier-supported iridium catalyst.

2. The method for preparing an amorphous carrier-supported iridium catalyst according to claim 1, wherein: The metal zirconium salt includes one or more of zirconium oxychloride octahydrate, zirconium nitrate, and calcium chloride; the metal strontium salt includes one or more of strontium nitrate, strontium chloride, and strontium acetate.

3. The method for preparing an amorphous carrier-supported iridium catalyst according to claim 1, characterized in that: The molar ratio of the metal zirconium salt to the metal strontium salt is 0.5-1.5:

1.

4. The method for preparing an amorphous carrier-supported iridium catalyst according to claim 1, characterized in that: The primary hydrothermal reaction has a hydrothermal temperature of 110 to 200° C., a hydrothermal time of 12 to 36 hours, and a heating rate of 3 to 5° C. / min.

5. The method for preparing an amorphous carrier-supported iridium catalyst according to claim 1, characterized in that: The Ir salt includes one or more of chloroiridic acid, iridium chloride, iridium acetylacetonate, iridium acetate, potassium chloroiridate, sodium chloroiridate, iridium oxide, strontium iridate, barium iridate, lithium iridate, potassium iridate or praseodymium iridate.

6. The method for preparing an amorphous carrier-supported iridium catalyst as claimed in claim 5, characterized in that: The molar ratio of the Zr element in the precursor SrZrO3 to the Ir element in the Ir salt is 0.25 to 2:

1.

7. The method for preparing an amorphous carrier-supported iridium catalyst according to claim 1, characterized in that: The stirring time is 5 to 24 hours.

8. The method for preparing an amorphous carrier-supported iridium catalyst according to claim 1, characterized in that: The secondary hydrothermal reaction has a hydrothermal temperature of 120 to 200° C., a hydrothermal time of 12 to 36 hours, and a heating rate of 3 to 5° C. / min.

9. An amorphous carrier-supported iridium catalyst prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The amorphous carrier-supported iridium catalyst uses amorphous zirconium oxide as a carrier, on which Ir clusters are supported; Wherein, the mass ratio of the Ir cluster to the amorphous zirconia carrier is 0.2-4:

1.

10. Use of the amorphous carrier-supported iridium catalyst as claimed in claim 9 in a proton exchange membrane water electrolysis reaction, characterized in that: The three-electrode system assembled with the amorphous carrier supporting the iridium catalyst has a catalyst loading of 0.5 mg / cm 2 Under the condition, it can reach 10mA / cm 2 The current density is <371mV; At 10mA / cm 2 The stable operation time at the current density is >150h and the voltage decay is <80mV.

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