A metal double oxide supported noble metal catalyst and its preparation method and application

Abstract

The present application relates to a homometallic double oxide supported noble metal catalyst, its preparation method and application, and belongs to the field of electrocatalytic material technology. The preparation method of the homometallic double oxide supported noble metal catalyst of the present application comprises the following steps: S1, dissolving the noble metal source and the homometallic double oxide carrier in water, stirring and ultrasonically uniformly to obtain a mixed solution; S2, adding a certain amount of nitrate to the mixed solution, stirring and drying to obtain a precursor solid; S3, calcining the precursor solid to obtain a solid product, and filtering, washing and drying the solid product to obtain the homometallic double oxide supported noble metal catalyst. The homometallic double oxide supported noble metal catalyst provided in the present application exhibits relatively excellent electrochemical performance in electrolyzed water, and has important research significance for promoting the industrialization process of catalysts with new homometallic double oxide carriers in electrolyzed water.

Description

Technical Field

[0001] The present application relates to the technical field of electrocatalytic materials, and in particular to a homometallic double oxide-supported noble metal catalyst, a preparation method thereof, and an application thereof. Background Art

[0002] The global energy landscape and environmental pollution are becoming increasingly severe. To meet these challenges, we must build a clean and renewable energy system. Hydrogen energy, with its advantages such as high energy density and zero pollution emissions, has attracted the attention and support of governments in many countries.

[0003] Most hydrogen atoms on Earth combine with oxygen to form water molecules. Therefore, water, as one of the main sources of hydrogen, has become an important raw material for hydrogen production. Using renewable energy sources (such as solar energy and wind energy) to drive the process of water electrolysis is considered a promising and sustainable way to produce clean hydrogen. This method not only effectively utilizes natural resources but also reduces carbon emissions, providing an environmentally friendly and sustainable solution to addressing the global energy crisis and environmental pollution.

[0004] The proton exchange membrane water electrolyzer (PEMWE) has become one of the most promising green hydrogen production technologies due to its multiple significant advantages. First, PEMWE has a high operating current density, which means it can efficiently produce more hydrogen in a shorter time. Second, its high energy efficiency maximizes the conversion of electrical energy into hydrogen, minimizing energy waste. Furthermore, the hydrogen produced by PEMWE is of extremely high purity, meeting the stringent hydrogen quality requirements of many applications. The PEMWE system is compact and easy to integrate, making it suitable for use in space-constrained environments. These advantages make PEMWE one of the most promising and promising technologies in the field of green hydrogen production.

[0005] However, the lifespan and cost issues of anode catalysts remain the main obstacles to the large-scale application of proton exchange membrane water electrolyzers (PEMWE). Therefore, research on anode catalysts for PEMWE electrolyzers has become particularly critical, as this issue directly affects the economy and long-term stability of the system. Improving the performance of anode catalysts, reducing their costs and extending their service life will be the key to promoting the widespread application of PEMWE technology. Due to the harsh chemical environment, only limited materials can be used as OER catalysts in acidic media. Iridium-based precious metal catalysts are the main choice, but due to their high cost and relatively low activity, this limits their popularity and economy in industrial-scale applications. The development of iridium-based acidic OER catalysts that are both durable and cost-effective is of great significance for promoting the widespread use of PEM electrolyzers in commercial applications. Summary of the Invention

[0006] In view of this, the present application provides a metal double oxide loaded precious metal catalyst and its preparation method and application. The metal double oxide loaded precious metal catalyst reduces the loading of precious metal catalyst and improves the activity of catalyst, reduces the cost of acidic OER catalyst, is of great significance to promote the commercialization process of proton exchange membrane water electrolyzer (PEMWE), and can effectively overcome the defects of the above-mentioned prior art.

[0007] In a first aspect, the present application provides a method for preparing a homometallic double oxide-supported noble metal catalyst, comprising the following steps:

[0008] S1, dissolving the noble metal source and the same metal double oxide support in water, stirring and ultrasonicating to obtain a mixed solution;

[0009] S2. adding a certain amount of nitrate to the mixed solution, stirring, and drying to obtain a precursor solid;

[0010] S3. calcining the precursor solid to obtain a solid product, filtering, washing, and drying the solid product to obtain a homometallic double oxide-supported noble metal catalyst.

[0011] Preferably, in step S1, the method for preparing the same metal double oxide support specifically comprises the following steps:

[0012] S11, titanyl sulfate, ethanol, ether and glycerol are mixed, stirred and ultrasonically treated to obtain a milky white mixed suspension;

[0013] S12, subjecting the milky white mixed suspension to a sealed solvent thermal reaction at a temperature of 100-150° C. (preferably 120-150° C.) for 12 h, and after the reaction is completed, washing by vacuum filtration to obtain a white solid of TiO2;

[0014] S13, drying the TiO2 white solid at 60-80°C overnight to obtain white TiO2 hollow tube powder;

[0015] S14. calcining the white TiO2 hollow tube powder to obtain a light yellow TiO2-TiO2 hollow tube powder, i.e., a homometallic double oxide support.

[0016] Preferably, in step S11, the usage ratio of titanyl sulfate, ethanol, ether and glycerol is 1g:(25ml-30ml):(15ml-18ml):(15ml-18ml).

[0017] Preferably, in step S11, the specific process of stirring and ultrasonic treatment is: stirring for 2 hours and ultrasonic treatment for 1 hour, alternately performed 3-5 times; or

[0018] In step S12, the specific process of the suction filtration and washing is: suction filtration with ethanol, and washing 4-6 times with 20-50 ml of ethanol each time.

[0019] Preferably, in step S14, the specific process of calcination is: placing the white TiO2 hollow tube powder in a muffle furnace, heating it from room temperature to 800-1000°C (preferably 800°C) at a heating rate of 2-10°C / min under an air atmosphere, and keeping it at this temperature for 2-5 hours.

[0020] 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; or

[0021] In step S1, the iridium source is IrCl3.XH2O, and the mass ratio of IrCl3.XH2O to the same metal double oxide support is (1-20 mg):20 mg; or

[0022] In step S1, the specific process of stirring and ultrasonicating is: ultrasonicating for 30 minutes and stirring for 15 minutes alternately for 3-5 times.

[0023] Preferably, in step S2, the stirring temperature is room temperature, and the stirring time is more than 6 hours; or

[0024] In step S2, the specific process of drying is: placing in a blast drying oven for drying, and the drying temperature is 60-120° C., and the drying time is 6-12 hours; or

[0025] In step S2, the drying is vacuum drying, the vacuum drying temperature is 60-120° C., and the drying time is 6-12 hours;

[0026] In step S2, the nitrate is selected from potassium nitrate and / or sodium nitrate.

[0027] Preferably, in step S3, the specific process of calcining is: placing the precursor solid in a muffle furnace, heating it from room temperature to 360-410°C at a heating rate of 2-10°C / min under air atmosphere, and keeping it at this temperature for 15min-2h; or

[0028] In step S3, the solvent used for the suction filtration and washing is ultrapure water, the washing times are 4 times, and 250 ml of ultrapure water is used each time, and the total volume of ultrapure water used is 1 L; or

[0029] In step S3, the specific process of drying is: placing in a blast drying oven for drying, the drying temperature is 60-80°C, and the drying time is 6-12h; or

[0030] In step S3, the drying is vacuum drying, the vacuum drying temperature is 60-120° C., and the drying time is 6-12 hours.

[0031] Specifically, an iridium source and a same-metal double oxide carrier are dissolved in water, and ultrasonic treatment is performed for 30 minutes and stirring is performed for 15 minutes alternately four times to obtain a mixed aqueous solution of the iridium source carrier; a certain amount of nitrate is weighed and added to the mixed aqueous solution of the iridium source carrier, and stirring is performed so that the iridium source is evenly distributed on the nitrate; and then the mixture is dried in an oven at 80°C for 6 hours to obtain a same-metal double oxide-loaded noble metal iridium dioxide precursor solid; the precursor solid is calcined to obtain a same-metal double oxide-loaded noble metal iridium dioxide catalyst and a certain amount of residual salt; and the above-mentioned muffle furnace product is filtered, washed, and dried to obtain a same-metal double oxide-loaded noble metal iridium dioxide catalyst.

[0032] The second aspect of the present application further provides a same-metallic double oxide-supported noble metal catalyst, which is prepared by the above-mentioned method.

[0033] The third aspect of the present application also provides the use of the above-mentioned isometallic double oxide-supported noble metal catalyst in PEM water electrolysis.

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

[0035] (1) The same metal double oxide supported noble metal iridium dioxide catalyst in this application, on the one hand, treats the corrosion-resistant and oxidative decomposition-resistant semiconductor material into a well-conductive carrier by a high-temperature oxidation method, and on the other hand, forms a heterogeneous structure on the carrier to improve the electrochemical activity and reduce the loading of the noble metal;

[0036] (2) The preparation method in this application can be easily extended to the preparation of other noble metal catalysts supported by other metal double oxides. It is a universal method with universal applicability;

[0037] (3) The same metal double oxide loaded noble metal iridium dioxide catalyst in this application shows relatively excellent electrochemical performance in electrolysis of water, providing a new research scheme for the industrial application of electrolysis of water; the new type of hollow same metal double oxide nanotube carrier obtained by this preparation method has good application prospects in the fields of electrocatalysis, photocatalysis, organic catalysis, biodiagnosis and treatment, especially in promoting the industrialization process of catalysts with oxides as carriers in electrolysis of water. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following briefly introduces the drawings required for use in the description of the present application or the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0039] Figure 1 Schematic diagram of the process for preparing IrO2 / TiO2-TiO2 in Example 1 of the present application;

[0040] Figure 2 is the XRD pattern of TiO2 in Example 1 of the present application;

[0041] Figure 3 is the XRD pattern of TiO2-TiO2 in Example 1 of the present application;

[0042] Figure 4 This is the XRD pattern of IrO2 / TiO2-TiO2 in Example 1 of the present application;

[0043] Figure 5 The conductivity diagram of TiO2-TiO2 and TiO2 in Example 1 of the present application;

[0044] Figure 6 This is the SEM image of TiO2-TiO2 in Example 1 of the present application;

[0045] Figure 7 This is the SEM image of IrO2 / TiO2-TiO2 in Example 1 of the present application;

[0046] Figure 8 TEM image of IrO2 / TiO2-TiO2 in Example 1 of the present application;

[0047] Figure 9 TEM image of TiO2-TiO2 in Example 1 of the present application;

[0048] Figure 10 This is a performance diagram of IrO2 / TiO2-TiO2 in Example 1 of this application, IrO2 / TiO2 in Comparative Example 1, and commercial IrO2 (Com-IrO2) in Comparative Example 2 in PEM. DETAILED DESCRIPTION

[0049] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0050] Unless otherwise specified, the experimental methods used in the examples of this application are all conventional methods.

[0051] In the following examples and comparative examples, unless otherwise specified, all raw materials can be purchased commercially or prepared by conventional methods.

[0052] Currently, in the field of electrochemical water splitting, the development of high-performance acidic OER electrocatalysts with excellent activity and durability is a key issue in promoting the large-scale application of PEM electrolyzers in large-scale hydrogen production.

[0053] High-performance electrocatalysts should possess the following advantages: good catalytic activity and acceptable cost. Due to the harsh chemical environment, only a limited number of materials can catalyze the OER in acidic media, with iridium-based precious metal catalysts currently being the primary choice. The high price of the precious metal iridium limits its commercial application. The development of iridium-based acidic OER catalysts that exhibit both excellent durability and cost-effectiveness is crucial for promoting the widespread commercialization of PEM electrolyzers.

[0054] Example 1

[0055] like Figure 1 As shown, the preparation method of the same metal double oxide supported noble metal iridium dioxide catalyst in this embodiment specifically includes the following steps:

[0056] S1. Preparation of TiO2-TiO2 carrier:

[0057] In a fume hood, 28 ml of ethanol, 16 ml of ether and 16 ml of glycerol were added to a 100 ml blue-capped bottle, and then 1 g of titanyl sulfate was added. After stirring and ultrasonication (stirring for 2 h and ultrasonication for 1 h were performed alternately 3-5 times), a milky white mixed suspension was obtained. Subsequently, the milky white mixed suspension was introduced into a 100 mL polytetrafluoroethylene-lined sealed solvent for thermal reaction for 12 h, and the sealed solvent thermal reaction temperature was 150 ° C. After the reaction was completed, vacuum filtration and alcohol washing (using ethanol) were performed. The mixture was filtered and washed 5 times with 30 ml of ethanol each time to obtain a white TiO2 solid; the solid was then placed in a blast drying oven and dried overnight at a temperature of 60°C for 12 hours to obtain a white TiO2 hollow tube powder; 5 g of the white TiO2 hollow tube powder was placed in a quartz boat and sintered in a muffle furnace under an air atmosphere at a heating rate of 2°C / min, a holding temperature of 800°C, and a holding time of 4 hours to obtain a TiO2-TiO2 carrier.

[0058] Preparation of S2, IrO2 / TiO2-TiO2 catalyst:

[0059] 20 mg TiO2-TiO2 carrier and 20 mg IrCl3.XH2O were weighed and dispersed in an aqueous solution and placed in a 20 ml glass bottle. After alternating three times of ultrasonic treatment for 30 min and stirring for 15 min, a uniform mixed solution was obtained; then 1 g sodium nitrate was added to the solution and stirring was continued at room temperature for 6 h; the obtained slurry was dried in an oven at 80°C for 6 h to obtain a yellow solid salt powder; the powder was kept at 360°C in a muffle furnace under an air atmosphere at a heating rate of 2°C / min for 2 h to obtain a black IrO2 / TiO2-TiO2 catalyst and some salt crystals; finally, it was washed with a large amount of deionized water (the washing solvent was ultrapure water, the washing number was 4, and 250 ml of ultrapure water was used each time, and the total volume of ultrapure water used was 1 L) and dried (placed in a blast drying oven for drying, the drying temperature was 60°C, and the drying time was 8 h) to obtain a pure IrO2 / TiO2-TiO2 catalyst.

[0060] Figure 3 X-ray diffraction phase analysis (XRD) revealed that TiO2-TiO2 matched well with two titanium dioxide standard cards PDF-89-4921 and PDF-89-2242, proving that the new carrier was successfully prepared. Figure 4 X-ray diffraction phase analysis (XRD) revealed that IrO2 / TiO2-TiO2 matched well with two titanium dioxide standard cards PDF-89-4921, PDF-89-2242, and iridium dioxide standard card PDF-86-0330, proving that the catalyst was successfully prepared. Figure 5 The conductivity of the carrier was tested and it was proved that TiO2-TiO2 had better conductivity than TiO2.

[0061] Figure 6 Scanning electron microscopy (SEM) was used to observe that TiO2-TiO2 is hollow nanotubes. Figure 7 Scanning electron microscopy (SEM) observation showed that the morphologies of IrO2 / TiO2-TiO and TiO2-TiO2 were similar. Figure 9 Transmission electron microscopy (TEM) was used to observe the TiO2-TiO2 lattice spacing and to find the heterogeneous interface of the two titanium dioxides. Figure 8 Transmission electron microscopy (TEM) revealed that IrO2 / TiO2-TiO2 dioxide nanowires were loaded onto TiO2-TiO2 flakes. Figure 10 The performance of IrO2 / TiO2-TiO2 in PEM was tested and its superior performance was demonstrated.

[0062] Example 2

[0063] The preparation method of the TiO2-TiO2 loaded noble metal iridium dioxide catalyst provided in this embodiment can refer to Example 1, except that, in step S2, the calcination temperature is 410°C and the calcination time is 15 minutes.

[0064] Example 3

[0065] The preparation method of the TiO2-TiO2 loaded noble metal iridium dioxide catalyst provided in this embodiment can refer to Example 1, except that, in step S2, the calcination temperature is 380°C and the calcination time is 1 hour.

[0066] Comparative Example 1

[0067] The preparation method of the titanium dioxide-supported noble metal iridium dioxide catalyst in this comparative example specifically comprises the following steps:

[0068] S1. Preparation of TiO2 hollow nanotube carrier:

[0069] In a fume hood, 28 ml of ethanol, 16 ml of ether and 16 ml of glycerol were added to a 100 ml blue-capped bottle, and then 1 g of titanium oxysulfate was added. After stirring and ultrasonication (stirring for 2 hours and ultrasonication for 1 hour alternately for 3-5 times) evenly, a milky white mixed suspension was obtained; the milky white mixed suspension was then introduced into a 100 mL polytetrafluoroethylene liner and subjected to a sealed solvent thermal reaction for 12 hours, and the sealed solvent thermal reaction temperature was 150°C. After the reaction was completed, vacuum filtration and alcohol washing (filtration with ethanol, washing 3 times with 30 ml of ethanol each time) were performed to obtain a white TiO2 solid; the solid was then placed in a blast drying oven and dried overnight, and the temperature of the blast drying oven was 60°C, and the drying time was 12 hours to obtain a white TiO2 hollow tube powder, i.e., a TiO2 carrier.

[0070] Preparation of S2, IrO2 / TiO2 catalyst:

[0071] Take 20mg TiO2 carrier and 20m gI Cl3.XH2O was dispersed in an aqueous solution and placed in a 20ml glass bottle. After ultrasonic stirring for 30 minutes and 15 minutes alternately three times, a uniform mixed solution was obtained; then 1g of sodium nitrate was added to the solution and stirring was continued at room temperature for 6h; the obtained slurry was dried in an oven at 80°C for 6h to obtain a yellow solid salt powder; the powder was kept at 360°C in a muffle furnace under an air atmosphere at a heating rate of 2°C / min for 2h to obtain a black IrO2 / TiO2 catalyst and some salt crystals; finally, it was washed with a large amount of deionized water (the washing solvent was ultrapure water, the washing number was 4, and 250ml of ultrapure water was used each time, and the total volume of ultrapure water used was 1L) and dried (placed in a blast drying oven for drying, the drying temperature was 60°C, and the drying time was 8h) to obtain a pure IrO2 / TiO2 catalyst.

[0072] Figure 2 X-ray diffraction phase analysis (XRD) revealed that TiO2 and the standard card PDF-89-2242 of titanium dioxide matched well, proving that the carrier was successfully prepared. Figure 5 The electrical conductivity of TiO2 was tested. Figure 10 The performance of IrO2 / TiO2 in PEM was tested and proved to be poor.

[0073] Comparative Example 2

[0074] Commercial IrO2 catalyst. Iridium dioxide, molecular formula: IrO2; CAS number: 12030-49-8; MDL number: MFCD00011065.

[0075] Anodic oxygen evolution performance test example

[0076] A linear scan test was performed using a PEM membrane electrode at a scan rate of 10 mV / s. Figure 10 The OER polarization curves of the IrO2 / TiO2-TiO2 catalyst prepared in Example 1, the IrO2 / TiO2 prepared in Comparative Example 1, and the commercial IrO2 catalyst in Comparative Example 2 in PEM are shown. Figure 10 It can be seen from the polarization curve that the catalyst prepared in Example 1 performs better than the IrO2 / TiO2 electrocatalyst with the same loading at a low loading and better than the commercial IrO2 with a high loading, showing an oxygen evolution performance that is superior to .

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing a metal double oxide supported iridium dioxide catalyst, characterized in that: The following steps are involved: S1, dissolving the iridium source and the metal double oxide support in water, stirring and ultrasonically homogenizing to obtain a mixed solution; S2. adding a certain amount of 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 an isometallic double oxide-supported iridium dioxide catalyst; In step S1, the preparation method of the same metal double oxide support specifically comprises the following steps: S11, titanyl sulfate, ethanol, ether and glycerol are mixed, stirred and ultrasonically treated to obtain a milky white mixed suspension; S12, subjecting the milky white mixed suspension to a sealed solvent thermal reaction at a temperature of 100-150° C. for 12 h, and after the reaction is completed, vacuum filtration and washing are performed to obtain a white solid of TiO2; S13, drying the TiO2 white solid at 60-80°C overnight to obtain white TiO2 hollow tube powder; S14, calcining the white TiO2 hollow tube powder to obtain a light yellow TiO2-TiO2 hollow tube powder, i.e., a homometallic double oxide support; In step S14, the specific process of the calcination is: placing the white TiO2 hollow tube powder in a muffle furnace, heating it from room temperature to 800-1000°C at a heating rate of 2-10°C / min under an air atmosphere, and keeping it at this temperature for 2-5 hours; In step S2, the nitrate is selected from potassium nitrate and / or sodium nitrate.

2. The method for preparing a homometallic double oxide supported iridium dioxide catalyst according to claim 1, wherein: In step S11, the usage ratio of titanyl sulfate, ethanol, ether and glycerol is 1 g: (25 ml-30 ml): (15 ml-18 ml): (15 ml-18 ml).

3. The preparation method of the same metal double oxide supported iridium dioxide catalyst according to claim 1, wherein In step S11, the specific process of stirring and ultrasonic treatment is: stirring for 2 hours and ultrasonic treatment for 1 hour, alternately 3-5 times; or In step S12, the specific process of the suction filtration and washing is: suction filtration with ethanol, and washing 4-6 times with 20-50 ml of ethanol each time.

4. The method for preparing a homometallic double oxide supported iridium dioxide catalyst according to claim 1, wherein: In step S1, the iridium source is selected from at least one of IrCl3.XH2O, K2IrCl6, and Na2IrCl6; or In step S1, the iridium source is IrCl3.XH2O, and the mass ratio of IrCl3.XH2O to the same metal double oxide support is (1-20 mg):20 mg; or In step S1, the specific process of stirring and ultrasonicating is: ultrasonicating for 30 minutes and stirring for 15 minutes alternately for 3-5 times.

5. The preparation method of the same metal double oxide supported iridium dioxide catalyst 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; or In step S2, the specific process of the drying is: placing it in a blast drying oven for drying, and the drying temperature is 60-120°C, and the drying time is 6-12h; or in step S2, the drying is vacuum drying, and the vacuum drying temperature is 60-120°C, and the drying time is 6-12h.

6. The method for preparing the same metal double oxide supported iridium dioxide catalyst according to claim 1, wherein: In step S3, the specific process of calcination is as follows: placing the precursor solid in a muffle furnace, heating it from room temperature to 360-410°C at a heating rate of 2-10°C / min under air atmosphere, and keeping it at this temperature for 15 minutes to 2 hours; or In step S3, the solvent used for the suction filtration and washing is ultrapure water, the washing times are 4 times, and 250 ml of ultrapure water is used each time, and the total volume of ultrapure water used is 1 L; or In step S3, the specific process of drying is: placing in a blast drying oven for drying, the drying temperature is 60-80°C, and the drying time is 6-12h; or In step S3, the drying is vacuum drying, the vacuum drying temperature is 60-120° C., and the drying time is 6-12 hours.

7. A metal double oxide supported iridium dioxide catalyst, characterized in that: A homometallic double oxide-supported iridium dioxide catalyst prepared by the method according to any one of claims 1 to 6.

8. Use of the same metal double oxide supported iridium dioxide catalyst according to claim 7 in PEM water electrolysis.

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