Same-metal double-oxide loaded noble metal catalyst as well as preparation method and application thereof

Abstract

The invention relates to an isometallic double-oxide supported noble metal catalyst as well as a preparation method and application thereof, and belongs to the technical field of electro-catalytic materials. The preparation method of the isometallic double-oxide loaded noble metal catalyst comprises the following steps: S1, dissolving a noble metal source and an isometallic double-oxide carrier in water, and performing uniform stirring and ultrasonic treatment to obtain a mixed solution; s2, adding a certain amount of nitrate into the mixed solution, stirring, and drying to obtain a precursor solid; and S3, calcining the precursor solid to obtain a solid product, carrying out suction filtration and washing on the solid product, and drying to obtain the isometallic double-oxide loaded noble metal catalyst. The isometallic double-oxide loaded noble metal catalyst provided by the invention shows relatively excellent electrochemical performance in electrolyzed water, and has important research significance for promoting the industrialization process of the isometallic double-oxide novel carrier catalyst in the 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-loaded noble metal catalyst and a preparation method and 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 has attracted the attention and support of many governments due to its advantages such as high energy density and zero pollution emissions.

[0003] Most of the 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 the production of hydrogen. The process of electrolyzing water using renewable energy (such as solar energy, wind energy, etc.) is considered to be a promising and sustainable way to produce clean hydrogen. This method can not only effectively utilize natural resources, but also reduce carbon emissions, providing an environmentally friendly and sustainable solution to the global energy crisis and environmental pollution problems.

[0004] Proton exchange membrane water electrolyzer (PEMWE) has become one of the most promising green hydrogen production technologies due to its many significant advantages. First, PEMWE has a high operating current density, which means that it can efficiently produce more hydrogen in a shorter time; second, it has high energy efficiency and can convert electrical energy into hydrogen to the greatest extent, reducing energy waste. In addition, the hydrogen produced by PEMWE is extremely pure, meeting the strict requirements of many applications for hydrogen quality. The PEMWE system is compact and easy to integrate, making it suitable for use in environments with limited space. These advantages make PEMWE one of the most promising and promising technologies in the field of green hydrogen production.

[0005] However, the life and cost 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 their high cost and relatively low activity limit 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] The first aspect of the present application provides a method for preparing a metal double oxide supported noble metal catalyst, comprising the following steps:

[0008] S1, dissolving the noble metal source and the same metal double oxide carrier in water, stirring and ultrasonically homogenizing 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 isometallic double oxide-supported noble metal catalyst.

[0011] Preferably, in step S1, the method for preparing the isometallic 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 hours, and after the reaction is completed, vacuum filtration and washing are performed to obtain a white solid of TiO2;

[0014] S13, drying the TiO2 white solid at 60-80° C. overnight to obtain a 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 carrier.

[0016] Preferably, in step S11, the dosage 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 are performed alternately 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 to 6 times with 20 to 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 in an air atmosphere, and keeping it at this temperature for 2-5h.

[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 carrier 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 calcination 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, ultrapure water is used as the solvent for the suction filtration and washing, 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 6-12 hours; 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 for 4 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 negative on the nitrate, and then drying is performed in an oven at 80°C for 6 hours to obtain a same-metal double oxide-loaded precious metal iridium dioxide precursor solid; the precursor solid is calcined to obtain a same-metal double oxide-loaded precious metal iridium dioxide catalyst and a certain amount of residual salt, and the muffle furnace product is filtered, washed, and dried to obtain a same-metal double oxide-loaded precious metal iridium dioxide catalyst.

[0032] The second aspect of the present application also provides a same-metallic double oxide loaded precious 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-loaded 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 the present application, on the one hand, treats the corrosion-resistant and oxidative decomposition-resistant semiconductor material into a carrier with good conductivity by manufacturing high-temperature oxidation method, and on the other hand, the carrier forms a heterogeneous structure to improve the electrochemical activity and reduce the loading of the noble metal;

[0036] (2) The preparation method in this application can be simply extended to the preparation of other precious metal catalysts supported by other metal double oxides, and is a universal method with universal applicability;

[0037] (3) The same metal double oxide supported noble metal iridium dioxide catalyst in the present application exhibits relatively excellent electrochemical performance in water electrolysis, providing a new research scheme for the industrial application of water electrolysis; 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 water electrolysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings required for use in the description of the present application or the prior art will be briefly introduced below. 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 paying 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 diagram 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] Fig. 9 TEM image of TiO2-TiO2 in Example 1 of the present application;

[0048] Fig.10 The performance diagram of IrO2 / TiO2-TiO2 in Example 1 of the present application, IrO2 / TiO2 in Comparative Example 1, and commercial IrO2 (Com-IrO2) in Comparative Example 2 in PEM. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work 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 obtained by commercial purchase or 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 have the following advantages: good catalytic activity and acceptable cost. Due to the harsh chemical environment, only limited materials can catalyze OER in acidic media, and iridium-based precious metal catalysts are currently mainly used. The high price of precious metal iridium limits its commercial application. The development of iridium-based acidic OER catalysts with excellent durability and cost-effectiveness is of great significance to promote the widespread use of PEM electrolyzers in commercial applications.

[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 comprises the following steps:

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

[0057] In a fume hood, add 28 ml of ethanol, 16 ml of ether and 16 ml of glycerol to a 100 ml blue-capped bottle, then add 1 g of titanyl sulfate, stir and ultrasonicate (stir for 2 h, ultrasonicate for 1 h alternately for 3-5 times) to obtain a milky white mixed suspension; then introduce the milky white mixed suspension into a 100 mL polytetrafluoroethylene liner and heat-react for 12 h in a sealed solvent, and the sealed solvent heat-reaction temperature is 150 ° C. After the reaction is completed, vacuum filtration and alcohol washing (using ethanol for Filter and wash 5 times with 30 ml of ethanol each time) to obtain a white solid TiO2; then put it into a blast drying oven and dry it overnight, and the temperature of the blast drying oven is 60°C, and the drying time is 12 hours to obtain a white TiO2 hollow tube powder; 5g of the white TiO2 hollow tube powder is put into a quartz boat, and sintered in a muffle furnace under an air atmosphere, with 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 ultrasonic treatment for 30 min and stirring for 15 min alternately for 3 times, 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 times were 4 times, 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 Through X-ray diffraction phase analysis (XRD), it was found that TiO2-TiO2 and two titanium dioxide standard cards PDF-89-4921 and PDF-89-2242 matched well, proving that the new carrier was successfully prepared. Figure 4 Through X-ray diffraction phase analysis (XRD), it was found 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. Fig. 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. Fig.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 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 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, add 28 ml of ethanol, 16 ml of ether and 16 ml of propylene glycol to a 100 ml blue-capped bottle, then add 1 g of titanyl sulfate, stir and ultrasonicate (stir for 2 hours, ultrasonicate for 1 hour alternately 3-5 times) to obtain a milky white mixed suspension; then introduce the milky white mixed suspension into a 100 mL polytetrafluoroethylene liner for a sealed solvent thermal reaction for 12 hours, and the sealed solvent thermal reaction temperature is 150°C. After the reaction is completed, vacuum filtration and alcohol washing (filtration with ethanol, washing 3 times with 30 ml of ethanol each time) are performed to obtain a white solid TiO2; then put it into a blast drying oven and dry it overnight, and the temperature of the blast drying oven is 60°C, and the drying time is 12 hours to obtain a white TiO2 hollow tube powder, i.e., a TiO2 carrier.

[0070] S2, IrO2 / TiO2 catalyst preparation:

[0071] Take 20mgTiO2 carrier and 20m iG Cl3.XH2O was dispersed in an aqueous solution and placed in a 20 ml glass bottle. After ultrasonic stirring for 30 min and 15 min alternately for 3 times, a uniform mixed solution was obtained. Subsequently, 1 g of 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 for 2 h in a muffle furnace under an air atmosphere at a heating rate of 2°C / min to obtain a black IrO2 / TiO2 catalyst and some salt crystals. Finally, it was washed with a large amount of deionized water (ultrapure water was used as the washing solvent, the washing times were 4 times, 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 catalyst.

[0072] Figure 2 Through X-ray diffraction phase analysis (XRD), it was found 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. Fig.10 The performance of IrO2 / TiO2 in PEM was tested and proved to be relatively poor.

[0073] Comparative Example 2

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

[0075] Anode 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. Fig.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. Fig.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 it. 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 replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate 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 noble metal catalyst, characterized in that: The following steps are involved: S1, dissolving the noble metal source and the same metal double oxide carrier 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 a metal double oxide-supported noble metal catalyst.

2. The method for preparing a noble metal catalyst supported by a same-metal double oxide according to claim 1, characterized in that: In step S1, the method for preparing 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 a 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 carrier.

3. The method for preparing a noble metal catalyst supported by a same-metal double oxide according to claim 2, characterized in that: In step S11, the dosage ratio of titanyl sulfate, ethanol, ether and glycerol is 1g:(25ml-30ml):(15ml-18ml):(15ml-18ml).

4. The method for preparing a noble metal catalyst supported by a same-metal double oxide according to claim 2, characterized in that: In step S11, the specific process of stirring and ultrasonic treatment is: stirring for 2 hours and ultrasonic treatment for 1 hour are performed 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 to 6 times with 20 to 50 ml of ethanol each time.

5. The method for preparing a noble metal catalyst supported by a same-metal double oxide according to claim 2, characterized in that: 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 at a heating rate of 2-10°C / min in an air atmosphere, and keeping it at this temperature for 2-5h.

6. The method for preparing a noble metal catalyst supported by a same-metal double oxide 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; or In step S1, the iridium source is IrCl3.XH2O, and the mass ratio of IrCl3.XH2O to the same metal double oxide carrier 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.

7. The method for preparing a noble metal catalyst supported by a same-metal double oxide 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 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 In step S2, the drying is vacuum drying, the vacuum drying temperature is 60-120° C., and the drying time is 6-12 hours; or In step S2, the nitrate is selected from potassium nitrate and / or sodium nitrate.

8. The method for preparing a noble metal catalyst supported by a same-metal double oxide according to claim 1, characterized in that: In step S3, the specific process of calcination 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 In step S3, ultrapure water is used as the solvent for the suction filtration and washing, 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 6-12 hours; 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.

9. A metal double oxide supported noble metal catalyst, characterized in that: A noble metal catalyst supported on a same-metal double oxide prepared by the method described in any one of claims 1 to 8.

10. Use of the same metal double oxide supported noble metal catalyst as claimed in claim 9 in PEM water electrolysis.

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