A nanosized oxide support loaded noble metal catalyst, a preparation method and application thereof

Abstract

This application relates to a nano-oxide-supported noble metal catalyst, its preparation method, and its application, belonging to the field of electrocatalytic materials technology. The preparation method of the nano-oxide-supported noble metal catalyst of this application includes the following steps: S1, dissolving a noble metal source and a nano-oxide support in an organic solvent, stirring and ultrasonically homogenizing to obtain a mixed solution; S2, adding nitrate to the mixed solution, stirring, and drying to obtain a precursor solid; S3, calcining the precursor solid to obtain a solid product, filtering, washing, and drying the solid product to obtain the nano-oxide-supported noble metal catalyst. The nano-oxide-supported iridium dioxide catalyst provided in this application exhibits superior electrochemical performance in water electrolysis, which is of significant research value for promoting the industrialization of supported catalysts in water electrolysis.

Description

Technical Field

[0001] This application relates to the field of electrocatalytic materials technology, and in particular to a nano-sized oxide-supported noble metal catalyst, its preparation method, and its application. Background Technology

[0002] Faced with the dual challenges of a severe global energy security situation and increasing environmental pressure, the transition to a clean and renewable energy system has become imperative. Hydrogen energy, with its significant advantages of high energy density and zero carbon emissions, is increasingly becoming a core focus of policy support and strategic planning in various countries.

[0003] Among numerous green hydrogen production technologies, the proton exchange membrane electrolyzer (PEMWE) has attracted considerable attention due to its multiple advantages. Firstly, it boasts high operating current density and outstanding hydrogen production efficiency. Secondly, it exhibits excellent energy conversion efficiency, minimizing power consumption. Furthermore, the produced hydrogen is of high purity, directly meeting the demands of high-end applications. Simultaneously, the system's compact structure and ease of integration make it particularly suitable for space-constrained deployment environments. These outstanding advantages have established PEMWE's important position in the field of green hydrogen production and demonstrated its strong development potential.

[0004] The key obstacle hindering the large-scale adoption of PEMWE lies in the lifespan and cost of the anode catalyst. Due to the harsh acidic environment within the electrolyzer, the number of OER catalysts capable of stable operation is extremely limited, currently relying mainly on iridium-based precious metals. However, iridium-based materials are expensive and have limited activity, directly impacting the system's economics and long-term stability. Therefore, developing low-cost, high-activity iridium-based catalysts has become a core issue for enhancing the technological competitiveness of PEMWE and achieving its commercialization. Summary of the Invention

[0005] In view of this, this application provides a nano-oxide-supported noble metal catalyst, its preparation method and application. The nano-oxide-supported noble metal catalyst reduces the loading of noble metal and improves the activity of the catalyst, thereby reducing the cost of acidic OER catalysts. It is of great significance to promote the commercialization of PEMWE and can effectively overcome the defects of the prior art.

[0006] The first aspect of this application provides a method for preparing a noble metal catalyst supported on a nano-oxide support, comprising the following steps:

[0007] S1. Dissolve the noble metal source and the nano-sized oxide carrier in an organic solvent, stir and sonicate until homogeneous to obtain a mixed solution;

[0008] S2. Add nitrate to the mixed solution, stir, and dry to obtain the precursor solid;

[0009] S3. The precursor solid is calcined to obtain a solid product, and the solid product is filtered, washed, and dried to obtain a nano-sized oxide support for a noble metal catalyst.

[0010] Preferably, in step S1, the preparation method of the nano-sized oxide support specifically includes the following steps:

[0011] S11. Dissolve ammonium carbonate and niobium oxalate in ultrapure water and stir to obtain a white flocculent suspension.

[0012] S12. The white flocculent suspension is subjected to a hydrothermal reaction to obtain a nano-sized oxide carrier precursor.

[0013] S13. The nano-oxide carrier precursor is centrifuged and washed, and the resulting solid is dried at a temperature of 60~80℃ to obtain a dried nano-oxide carrier precursor.

[0014] S14. The dried nano-oxide carrier precursor is calcined to obtain a light yellow nano-oxide carrier.

[0015] Preferably, in step S11, the ratio of ammonium carbonate, niobium oxalate, and ultrapure water is 1.44 g: 1.61 g: 50 ml.

[0016] In step S11, the specific conditions for stirring are: sealing at room temperature and stirring for 10 minutes;

[0017] In step S12, the temperature of the hydrothermal reaction is 200°C, and the reaction time is 24 hours.

[0018] In step S13, the specific process of centrifugal washing is as follows: the solvent used is ethanol and ultrapure water, and the volume ratio of ethanol to ultrapure water is 1:1, and the washing is performed 5 times.

[0019] In step S13, the drying temperature is 60°C and the drying time is 6 hours.

[0020] In step S14, the specific calcination conditions are as follows: the dried nano-oxide carrier precursor is placed in a tube furnace and calcined at 450~800℃ for 2 hours in a mixed atmosphere of argon and hydrogen, and the volume ratio of argon to hydrogen is 95:5.

[0021] Preferably, in step S1, the noble metal source is an iridium source, and the iridium source is selected from at least one of IrCl3·XH2O, K2IrCl6, and Na2IrCl6;

[0022] In step S1, the organic solvent is ethanol.

[0023] Preferably, the iridium source is IrCl3·XH2O, and the ratio of IrCl3·XH2O, nano-sized oxide carrier, and ethanol is (1~20 mg):20 mg:10 ml.

[0024] Preferably, in step S1, the specific process of the stirring and ultrasonication is as follows: alternating between ultrasonication for 30 minutes and stirring for 15 minutes 3 to 5 times.

[0025] Preferably, in step S2, the stirring temperature is room temperature and the stirring time is 6 hours or more;

[0026] In step S2, the drying is performed using vacuum drying, with a temperature of 60~120℃ and a drying time of 6~12h.

[0027] In step S2, the nitrate is potassium nitrate and / or sodium nitrate.

[0028] Preferably, in step S3, the specific process of calcination is as follows: the precursor solid is placed in a muffle furnace, and the temperature is increased from room temperature to 300-500°C at a heating rate of 2-10°C / min under an air atmosphere, and held at this temperature for 15 min-2 h.

[0029] In step S3, the specific process of the vacuum filtration and washing is as follows: the solvent is ultrapure water, the washing is performed 4 times, and 250ml of ultrapure water is used each time, with a total volume of 1L of ultrapure water used.

[0030] In step S3, the specific drying process is as follows: place the product in a forced-air drying oven for drying at a temperature of 60~80℃ for 6~12 hours.

[0031] Specifically, 1.44 g of ammonium carbonate, 1.61 g of niobium oxalate, and 50 ml of ultrapure water were weighed and stirred vigorously at room temperature for 10 min. The stirred solution was then transferred to a high-pressure reactor for hydrothermal treatment at 200 °C for 24 h. After the reaction, the product was washed by centrifugation using ethanol and ultrapure water in a 1:1 volume ratio, five times. The washed product was then dried at 60 °C for 6 h. Finally, it was calcined in a tube furnace under a mixed atmosphere of argon and hydrogen (95:5 volume ratio) at 450 °C for 2 h to obtain a pale yellow support. 20 mg of iridium source IrCl3·XH2O and 20 mg of nano-sized oxide support were dissolved in 10 ml of ethanol and subjected to alternating sonication for 30 min and stirring for 15 min four times to obtain a mixed solution. 10 g of nitrate was weighed and added to the mixed solution and stirred to ensure that the iridium source was uniformly coated on the nitrate. The solution was then dried in a vacuum oven at 80 °C for 6 h to obtain a precursor solid of noble metal iridium dioxide supported on nano-sized oxide support. The precursor solid was annealed in a muffle furnace at 350 °C for 2 h to obtain a catalyst of noble metal iridium dioxide supported on nano-sized oxide support and a certain amount of residual salt. The above product was filtered, washed, and dried with ultrapure water to obtain a catalyst of noble metal iridium dioxide supported on nano-sized oxide support.

[0032] The second aspect of this application also provides a nano-oxide-supported noble metal catalyst, which is prepared by the above method.

[0033] The third aspect of this application also provides the application of the above-mentioned nano-oxide-supported noble metal catalyst in PEMWE.

[0034] Compared with the prior art, this application has the following advantages:

[0035] (1) The nano-oxide support for the noble metal iridium dioxide catalyst in this application, on the one hand, the corrosion-resistant and oxidation-resistant semiconductor material is processed into a carrier with good conductivity by manufacturing a high-temperature oxidation method, and on the other hand, the nano-oxide support improves the electrochemical activity and reduces the loading of noble metal.

[0036] (2) The preparation method in this application can be easily extended to the preparation of other precious metal catalysts supported on other nano-sized oxide supports. It is a universal method with universality.

[0037] (3) The nano-oxide support for the noble metal iridium dioxide catalyst in this application exhibits superior electrochemical performance in water electrolysis, providing a new research scheme for the industrial application of water electrolysis. The hollow monometallic double nano-oxide support obtained by this preparation method has good application prospects in electrocatalysis, photocatalysis, organic catalysis, bio-diagnosis and other fields, and is of great research significance for promoting the industrialization of catalysts with nano-oxide support in water electrolysis. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of this application or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0039] Figure 1 This is a schematic flowchart of the preparation method of IrO2 / Nb2O5-Ar-H2 in Example 1 of this application;

[0040] Figure 2 The XRD patterns of Nb2O5 and Nb2O5-Ar-H2 in Example 1 of this application are shown.

[0041] Figure 3 This is a SEM image of Nb2O5-Ar-H2 in Example 1 of this application;

[0042] Figure 4 This is a TEM image of IrO2 / Nb2O5-Ar-H2 in Example 1 of this application;

[0043] Figure 5 These are performance graphs of Embodiments 1, 2, and 3 of this application in PEM.

[0044] Figure 6 The graphs show the performance of commercial IrO2 (C-IrO2) in PEM in Example 1 and Comparative Example 1 of this application.

[0045] Figure 7 A comparison diagram of the electrical conductivity of Nb2O5-Ar-H2 and Nb2O5. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] Unless otherwise specified, the experimental methods used in the embodiments of this application are all conventional methods.

[0048] In the following examples and comparative examples, unless otherwise specified, all raw materials can be prepared by commercial purchase or conventional methods.

[0049] Developing acidic OER electrocatalysts that combine high activity and high durability is a core challenge for advancing large-scale hydrogen production in PEM electrolyzers. An ideal catalyst must simultaneously meet the dual requirements of excellent catalytic performance and acceptable cost. However, the acidic OER environment imposes extremely stringent material limitations; currently, only iridium-based noble metal catalysts are practically available, and their high price is a major obstacle to commercialization. Therefore, developing cost-effective and highly durable iridium-based catalysts is crucial for the widespread commercial application of PEM electrolyzers.

[0050] Example 1

[0051] like Figure 1 As shown in this embodiment, the preparation method of the noble metal iridium dioxide catalyst supported on a nano-oxide support specifically includes the following steps:

[0052] S1. Preparation of Nb2O5-Ar-H2 support:

[0053] 1.44 g of ammonium carbonate and 1.61 g of niobium oxalate were dissolved in 50 ml of ultrapure water, sealed at room temperature, and vigorously stirred for 10 min. The stirred solution was then transferred to a high-pressure reactor for hydrothermal treatment at 200 °C for 24 h. After the reaction, the mixture was centrifuged and washed five times with ethanol and ultrapure water in a 1:1 volume ratio. The washed product was dried at 60 °C for 6 h. Finally, it was calcined in a tube furnace at 450 °C for 2 h under a mixed atmosphere of argon and hydrogen, with an argon to hydrogen volume ratio of 95:5, to obtain the Nb₂O₅-Ar-H₂ support. Figure 2 XRD analysis revealed that the peaks corresponding to the prepared Nb₂O₅-Ar-H₂ support and Nb₂O₅ remained unchanged after Ar-H₂ treatment, demonstrating the stability of the crystal structure. However, through... Figure 7 Conductivity diagrams demonstrate that Ar-H2 treatment improves the conductivity of the carrier. (By...) Figure 3 The synthesis of nanoflower structures has been demonstrated.

[0054] S2, Ir 3+ Preparation of / Nb2O5-Ar-H2:

[0055] Weigh 20 mg of Nb2O5-Ar-H2 support and 20 mg of IrCl3.XH2O, disperse them in 10 ml of ethanol solution, and place them in a 20 ml glass bottle. After sonicating for 30 min and stirring for 15 min alternately three times, a homogeneous mixed solution is obtained. Then, 5 g of sodium nitrate and 5 g of potassium nitrate are added to the solution, and stirring is continued at room temperature for 6 h. The resulting slurry is dried in a vacuum oven at 80 °C for 6 h to obtain a yellow solid salt powder.

[0056] Preparation of S3, IrO2 / Nb2O5-Ar-H2:

[0057] The powder was ground and then placed in a quartz boat in a muffle furnace at a heating rate of 5℃ / min, held at 350℃ for 2 hours to obtain a black IrO2 / Nb2O5-550℃ catalyst and some salt crystals. Finally, it was washed with a large amount of deionized water (4 times, 250 ml each time, totaling 1 L) and dried (in a forced-air drying oven at 60℃ for 8 hours) to obtain pure IrO2 / Nb2O5-550℃ catalyst, denoted as Nb2O5-Ar-H2 / IrO2. Figure 4 High-magnification TEM confirmed that IrO2 particles were uniformly distributed on the Nb2O5-Ar-H2 carrier nanofloral sheets.

[0058] Example 2

[0059] like Figure 1 As shown in this embodiment, the preparation method of the noble metal iridium dioxide catalyst supported on a nano-oxide support specifically includes the following steps:

[0060] S1. Preparation of Nb2O5-550℃ support:

[0061] 1.44 g of ammonium carbonate and 1.61 g of niobium oxalate were dissolved in 50 ml of ultrapure water, sealed at room temperature, and stirred vigorously for 10 min. The stirred solution was then transferred to a high-pressure reactor for hydrothermal treatment at 200 °C for 24 h. After the reaction, the product was washed by centrifugation using ethanol and ultrapure water in a 1:1 volume ratio, five times. The washed product was dried at 60 °C for 6 h. Finally, it was calcined in a tube furnace at 550 °C for 2 h under a mixed atmosphere of argon and hydrogen, with an argon to hydrogen volume ratio of 95:5, to obtain the Nb₂O₅-Ar-H₂ support.

[0062] S2, Ir 3+Preparation of / Nb2O5 at 550℃:

[0063] Weigh 20 mg of Nb2O5-550℃ carrier and 20 mg of IrCl3.XH2O, disperse them in 10 ml of ethanol solution, and place them in a 20 ml glass bottle. After sonicating for 30 min and stirring for 15 min alternately three times, a homogeneous mixed solution is obtained. Then, 5 g of sodium nitrate and 5 g of potassium nitrate are added to the solution, and stirring is continued at room temperature for 6 h. The resulting slurry is dried in a vacuum oven at 80℃ for 6 h to obtain a yellow solid salt powder.

[0064] Preparation of S3, IrO2 / Nb2O5 at -550℃:

[0065] The powder was ground and then placed in a quartz boat and heated in a muffle furnace at 350℃ for 2 hours at a heating rate of 5℃ / min to obtain a black IrO2 / Nb2O5-550℃ catalyst and some salt crystals. Finally, it was washed with a large amount of deionized water (4 times, 250 ml each time, for a total volume of 1 L) and dried (in a forced-air drying oven at 60℃ for 8 hours) to obtain a pure IrO2 / Nb2O5-550℃ catalyst, denoted as Nb2O5-550℃ / IrO2.

[0066] Example 3

[0067] The preparation method of the IrO2 / Nb2O5-800℃ catalyst provided in this embodiment can be referred to in Example 1. The difference is that in step S1, the calcination temperature is 800℃, which is denoted as Nb2O5800℃ / IrO2.

[0068] Comparative Example 1

[0069] Commercial IrO2 catalyst. Iridium dioxide (IrO2); CAS No.: 12030-49-8; MDL No.: MFCD00011065. Denoted as C-IrO2.

[0070] Anode Oxygen Evolution Performance Test Example

[0071] A PEM film electrode was used, and a linear scan test was performed at a scan rate of 10 mV / s. According to... Figure 5 The polarization curves show that the catalyst prepared in Example 1 performs better than the electrocatalysts of Examples 2 and 3 with the same loading at a low loading. Figure 6 Example 1 of this application shows that its performance is superior to that of commercial IrO2 with high loading, exhibiting excellent oxygen evolution performance.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for preparing a noble metal catalyst supported on a nano-sized oxide support, characterized in that, Includes the following steps: S1. Dissolve the noble metal source and the nano-sized oxide carrier in an organic solvent, stir and sonicate until homogeneous to obtain a mixed solution; S2. Add nitrate to the mixed solution, stir, and dry to obtain the precursor solid; S3. The precursor solid is calcined to obtain a solid product, and the solid product is filtered, washed, and dried to obtain a nano-sized oxide support for a noble metal catalyst.

2. The method for preparing a noble metal catalyst supported on a nano-oxide support according to claim 1, characterized in that, In step S1, the preparation method of the nano-sized oxide support specifically includes the following steps: S11. Dissolve ammonium carbonate and niobium oxalate in ultrapure water and stir to obtain a white flocculent suspension. S12. The white flocculent suspension is subjected to a hydrothermal reaction to obtain a nano-sized oxide carrier precursor. S13. The nano-oxide carrier precursor is centrifuged and washed, and the resulting solid is dried at a temperature of 60~80℃ to obtain a dried nano-oxide carrier precursor. S14. The dried nano-oxide carrier precursor is calcined to obtain a light yellow nano-oxide carrier.

3. The method for preparing a noble metal catalyst supported on a nano-oxide support according to claim 2, characterized in that, In step S11, the ratio of ammonium carbonate, niobium oxalate, and ultrapure water is 1.44 g: 1.61 g: 50 ml. In step S11, the specific conditions for stirring are: sealing at room temperature and stirring for 10 minutes; In step S12, the temperature of the hydrothermal reaction is 200°C, and the reaction time is 24 hours. In step S13, the specific process of centrifugal washing is as follows: the solvent used is ethanol and ultrapure water, and the volume ratio of ethanol to ultrapure water is 1:1, and the washing is performed 5 times. In step S13, the drying temperature is 60°C and the drying time is 6 hours. In step S14, the specific calcination conditions are as follows: the dried nano-oxide carrier precursor is placed in a tube furnace and calcined at 450~800℃ for 2 hours in a mixed atmosphere of argon and hydrogen, and the volume ratio of argon to hydrogen is 95:

5.

4. The method for preparing a noble metal catalyst supported on a nano-oxide support according to claim 1, characterized in that, In step S1, the noble metal source is an iridium source, and the iridium source is selected from at least one of IrCl3·XH2O, K2IrCl6, and Na2IrCl6; In step S1, the organic solvent is ethanol.

5. The method for preparing a noble metal catalyst supported on a nano-oxide support according to claim 4, characterized in that, The iridium source is IrCl3.XH2O, and the ratio of IrCl3.XH2O, nano-oxide carrier and ethanol is (1~20mg):20mg:10ml.

6. The method for preparing a noble metal catalyst supported on a nano-oxide support according to claim 1, characterized in that, In step S1, the specific process of the stirring and ultrasonication is as follows: alternating between ultrasonication for 30 minutes and stirring for 15 minutes 3 to 5 times.

7. The method for preparing a noble metal catalyst supported on a nano-oxide support according to claim 1, characterized in that, In step S2, the stirring temperature is room temperature, and the stirring time is more than 6 hours. In step S2, the drying is performed using vacuum drying, with a temperature of 60~120℃ and a drying time of 6~12h. In step S2, the nitrate is potassium nitrate and / or sodium nitrate.

8. The method for preparing a noble metal catalyst supported on a nano-oxide support according to claim 1, characterized in that, In step S3, the specific process of calcination is as follows: the precursor solid is placed in a muffle furnace and heated to 300-500°C from room temperature in an air atmosphere at a heating rate of 2-10°C / min, and held at this temperature for 15 min-2 h. In step S3, the specific process of the vacuum filtration and washing is as follows: the solvent is ultrapure water, the washing is performed 4 times, and 250ml of ultrapure water is used each time, with a total volume of 1L of ultrapure water used. In step S3, the specific drying process is as follows: place the product in a forced-air drying oven for drying at a temperature of 60~80℃ for 6~12 hours.

9. A noble metal catalyst supported on a nano-oxide support, characterized in that, The nano-sized oxide support for noble metal catalyst prepared by the method described in any one of claims 1 to 8.

10. The application of the nano-oxide support-supported noble metal catalyst according to claim 9 in PEMWE.

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