Preparation method and application of molybdenum dioxide supported platinum catalyst
By preparing molybdenum dioxide-supported platinum catalyst, the existing platinum-based hydrogen evolution electrocatalysts are solved, and the combination of efficient catalytic activity and low metal platinum usage in the electrolytic hydrogen production process is achieved, which significantly improves the economic and stability of hydrogen production.
Patent Information
- Application Number
- CN202510323556.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-19
- Publication Date
- 2025-06-17
AI Technical Summary
Existing platinum-based hydrogen evolution electrocatalysts are expensive, limiting their widespread use in the production of hydrogen.
The preparation method of molybdenum dioxide-supported platinum catalyst is adopted. Acetylacetonate and molybdenum acetylacetonate are used as metal raw materials, and a rapid carbon-heat shock reaction is completed using a Joule heating device to prepare a molybdenum dioxide-supported platinum catalyst supported on the surface of carbon paper, effectively dispersing the metal platinum and reducing its usage amount.
While improving the catalytic activity of hydrogen production by electrolytic water, the use of metal platinum is significantly reduced, efficient hydrogen production is achieved, and significant improvements are made in terms of stability and economy.
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Figure CN120158766A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of nano-catalysts, and particularly relates to a preparation method and application of a platinum-loaded molybdenum dioxide catalyst. Background Art
[0002] As a high-energy density and environmentally friendly energy carrier, hydrogen is considered to be an important part of the future energy structure. Therefore, the development of a hydrogen energy economy is of great significance for building a low-carbon energy system. So far, the main methods for large-scale hydrogen production in industry are the methane steam method and the coal gas method. Although the above methods are widely used in large-scale hydrogen production, they inevitably produce toxic and harmful gases such as carbon dioxide and carbon monoxide during the hydrogen production process, which are released into the atmosphere and cause environmental pollution. Therefore, there is an urgent need to find an environmentally friendly and pollution-free hydrogen production method.
[0003] Among different hydrogen production methods, water electrolysis for hydrogen production is currently the most promising hydrogen production method. This is mainly attributed to the following reasons: water electrolysis for hydrogen production only generates hydrogen and oxygen, without pollutant gas emissions; the purity of the prepared hydrogen is as high as 99%, which is sufficient for various applications; the hydrogen production raw materials are abundant, and the raw materials can be reused.
[0004] Efficient hydrogen evolution reaction is crucial for realizing water splitting for hydrogen production. Developing efficient hydrogen production electrocatalysts is of great significance for promoting the goal of using clean energy. Currently, the most common catalysts are generally platinum-based catalysts. Catalysts based on platinum group metals and their derivatives have long been considered the most effective hydrogen evolution reaction catalysts because they have the best hydrogen binding energy and Gibbs free energy of atomic hydrogen adsorption, as well as a low activation energy for hydrogen desorption from the surface, which can provide a high exchange current density close to the thermodynamic potential and a small Tafel slope, and produce a Faraday efficiency close to 100%. However, the high cost and insufficient reserves of platinum and other platinum group precious metals on the earth limit the wide application of platinum-based catalysts in hydrogen production. Summary of the Invention
[0005] Aiming at the problem of the high cost of existing platinum-based hydrogen evolution electrocatalysts, the present invention provides a preparation method and application of a platinum-loaded molybdenum dioxide catalyst, which can significantly reduce the usage amount of metallic platinum while enhancing the catalytic activity of water electrolysis for hydrogen production.
[0006] The technical solution adopted by the present invention is as follows:
[0007] A preparation method of a platinum-loaded molybdenum dioxide catalyst, comprising the following steps:
[0008] Step 1: Weigh platinum acetylacetonate and molybdenum acetylacetonate, dissolve them in a volatile organic solvent to obtain a uniform mixed solution;
[0009] Step 2: Dropwise coat the mixed solution onto the carbon paper, and keep heating the carbon paper during the dropwise coating process to completely volatilize the organic solvent. Repeat the dropwise coating-heating process multiple times to obtain the carbon paper loaded with the precursor sample.
[0010] Step 3: Fix the carbon paper loaded with the precursor sample in a Joule heating device. After evacuating the air, react by adjusting the input current and the application time to obtain the molybdenum dioxide supported platinum catalyst loaded on the surface of the carbon paper.
[0011] Further, in Step 1, the molar ratio of platinum acetylacetonate to molybdenum acetylacetonate is 1-3:1-3, and the solute concentration in the mixed solution is 0.02-0.08 mol / L.
[0012] Further, in Step 1, the organic solvent is acetone.
[0013] Further, in Step 2, the carbon paper is raw carbon paper, preferably TGPH-060 raw carbon paper.
[0014] Further, after repeating the dropwise coating-heating process multiple times in Step 2, ensure that the total dropwise coating amount of the mixed solution on the carbon paper is 250-350 μL / cm 2 。
[0015] Further, in Step 2, the heating temperature is not higher than 80 °C.
[0016] Further, in Step 3, by adjusting the input current, the reaction temperature is 750 °C - 850 °C, and the application time is 10 s.
[0017] Further, the range of the input current adjusted in Step 3 is 16-20 A.
[0018] Further, the mass fraction of metallic platinum in the molybdenum dioxide supported platinum catalyst is 0.4% - 1.12%.
[0019] The present invention also provides an application of the molybdenum dioxide supported platinum catalyst obtained by the preparation method according to any one of the above technical solutions in electrocatalytic electrolytic water for hydrogen production.
[0020] An electrocatalytic electrolytic water for hydrogen production device uses the carbon paper with the molybdenum dioxide supported platinum catalyst loaded on its surface as the working electrode.
[0021] Further, the electrocatalytic electrolytic water for hydrogen production device is realized based on an H-type electrolytic cell, and the electrolyte used is sulfuric acid.
[0022] Compared with the prior art, the beneficial effects of the present invention are:
[0023] 1. The present invention provides a method for preparing a molybdenum dioxide supported platinum catalyst and its application. Using platinum acetylacetonate and molybdenum acetylacetonate as metal raw materials, a rapid carbothermal shock reaction is completed by a Joule heating device to obtain a molybdenum dioxide supported platinum catalyst loaded on the surface of carbon paper. On the one hand, the metal platinum is effectively dispersed to expose more reaction active sites. On the other hand, the interaction between the metal platinum and the molybdenum dioxide support is utilized to reduce the hydrogen adsorption capacity of the metal platinum and enhance the activity and stability of the catalytic system. Finally, while improving the catalytic activity of water electrolysis for hydrogen production, the present invention significantly reduces the usage amount of metal platinum.
[0024] 2. Preferably, the molybdenum dioxide supported platinum catalyst obtained in the present invention, with a metal platinum usage amount of 1.12%, is applied to the three - electrode system of an H - type electrolytic cell, and the overpotential for achieving a current density of 10 milliamperes per square centimeter is only 13 millivolts, and stable hydrogen production by electrolysis can be maintained for more than 40 hours at a current density of 10 milliamperes per square centimeter. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following - described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0026] Figure 1 It is a high - resolution transmission electron microscope photograph of the molybdenum dioxide supported platinum catalyst obtained in Example 1 of the present invention;
[0027] Figure 2 It is an X - ray energy spectrum analysis diagram of the molybdenum dioxide supported platinum catalyst obtained in Example 1 of the present invention;
[0028] Figure 3 It is a comparison diagram of X - ray diffraction spectra of the molybdenum dioxide supported platinum catalyst obtained in Example 1 of the present invention, the pure platinum metal catalyst without molybdenum dioxide support obtained in Comparative Example 1, and molybdenum dioxide;
[0029] Figure 4 It is a comparison diagram of X - ray photoelectron spectra of the molybdenum dioxide supported platinum catalyst obtained in Example 1 of the present invention and the pure platinum metal catalyst without molybdenum dioxide support obtained in Comparative Example 1;
[0030] Figure 5 It is a hydrogen evolution current density curve at different potentials during the hydrogen production reduction reaction of the molybdenum dioxide supported platinum catalyst obtained in Example 1 of the present invention;
[0031] Figure 6It is the change curve of overpotential with time at a current density of 10 mA / cm² in the hydrogen production reduction reaction of electrolyzed water for the molybdenum dioxide supported platinum catalyst obtained in Example 1 of the present invention;
[0032] Figure 7 It is the hydrogen evolution current density curve at different potentials in the hydrogen production reduction reaction of electrolyzed water for the pure platinum metal catalyst without molybdenum dioxide support obtained in Comparative Example 1;
[0033] Figure 8 It is the change curve of overpotential with time at a current density of 10 mA / cm² in the hydrogen production reduction reaction of electrolyzed water for the molybdenum dioxide supported platinum catalyst obtained in Example 2 of the present invention;
[0034] Figure 9 It is the change curve of overpotential with time at a current density of 10 mA / cm² in the hydrogen production reduction reaction of electrolyzed water for the molybdenum dioxide supported platinum catalyst obtained in Example 3 of the present invention. Detailed implementation mode
[0035] In order to further understand the present invention, the preferred implementation schemes of the present invention will be described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the invention.
[0036] There are no special restrictions on the sources of all raw materials of the present invention, and they can be purchased on the market or prepared by conventional methods well-known to those skilled in the art.
[0037] There are no special restrictions on the purity of all raw materials of the present invention. The present invention preferably adopts analytical pure or the conventional purity requirements in the field of atomic layer deposition.
[0038] All raw materials and process procedures of the present invention, their trade names or abbreviations all belong to the conventional trade names or abbreviations in the field, and each trade name or abbreviation is clear and definite in the field of its related uses. Those skilled in the art can purchase or prepare them by conventional methods according to the trade name, abbreviation and corresponding uses, or implement them using the corresponding equipment.
[0039] The present invention will be further described in detail below in conjunction with examples:
[0040] Example 1
[0041] This example prepared a molybdenum dioxide supported platinum catalyst, which specifically included the following steps:
[0042] Step 1: Weigh 59.0 mg of platinum acetylacetonate and 48.9 mg of molybdenum acetylacetonate, place them in a 10 mL glass vial, add 3.75 mL of acetone solution, and dissolve them by ultrasonic treatment to obtain a uniform mixed solution;
[0043] Step 2: Dropwise coat the mixed solution onto the TGPH-060 carbon paper with a size of 2×6 cm 2 and heat the carbon paper using a heating stage during the dropwise coating process. The heating temperature is 80 °C to completely volatilize acetone. Repeat the dropwise coating-heating process multiple times to ensure that the total dropwise coating amount of the mixed solution on the carbon paper is 250 μL / cm 2 , obtaining the carbon paper loaded with the precursor sample;
[0044] Step 3: Fix the carbon paper loaded with the precursor sample in a Joule heating device, evacuate to -0.082 MPa, adjust the input current to 20 A, and apply the current for 10 s to make the reaction temperature between 750 °C and 850 °C, and react to obtain the molybdenum dioxide supported platinum catalyst loaded on the surface of the carbon paper.
[0045] By inductively coupled plasma atomic emission spectrometry, it is determined that the mass fraction of platinum atoms in the molybdenum dioxide supported platinum catalyst obtained in this example is 1.12%.
[0046] The high-resolution transmission electron microscope photograph of the molybdenum dioxide supported platinum catalyst obtained in this example is as shown in Figure 1 , and the X-ray energy spectrum analysis diagram is as shown in Figure 2 . It can be seen that the platinum element exists in the form of metallic platinum particles, and the size of the metallic platinum particles is 3 - 10 nm, uniformly loaded on the surface of molybdenum dioxide, indicating that the molybdenum dioxide supported platinum catalyst obtained in this example can effectively disperse metallic platinum to expose more reaction active sites.
[0047] Use an H-type commercial electrolytic cell to test the hydrogen evolution performance of the molybdenum dioxide supported platinum catalyst obtained in this example for water electrolysis.
[0048] Specifically, in the H-type commercial electrolytic cell, use the molybdenum dioxide supported platinum catalyst loaded on the surface of the carbon paper obtained in this example as the cathode, the mercury / mercurous sulfate electrode as the reference electrode, and the carbon rod as the anode (where oxygen evolution reaction occurs); use dilute sulfuric acid with a concentration of 0.5 mol / L as the electrolyte, and immerse the carbon paper with an area of 1 cm 2 loaded with the molybdenum dioxide supported platinum catalyst in the electrolyte. The ion exchange membrane in the middle of the electrolytic cell is the nafion117 membrane.
[0049] Use a Chenhua electrochemical workstation to test the polarization curve performance of the molybdenum dioxide supported platinum catalyst obtained in this example. The test results are as shown in Figure 5 . It can be seen that this catalyst achieves a current density of 10 mA / cm² at an overpotential of 13 mV.
[0050] Use a Chenhua electrochemical workstation to test the stability of the molybdenum dioxide supported platinum catalyst obtained in this example. The test uses a constant current method, and the test results are as shown in Figure 6As shown, it can be seen that the catalyst can stably operate for more than 40 hours at a current density of 10 mA / cm².
[0051] Comparative Example 1
[0052] In this comparative example, a pure platinum metal catalyst without molybdenum dioxide loading was prepared, which specifically included the following steps:
[0053] Step 1: Weigh 59.0 mg of platinum acetylacetonate, place it in a 10 mL glass vial, add 3.75 mL of acetone solution, and ultrasonically dissolve it to obtain a uniform mixed solution;
[0054] Step 2: Dropwise coat the mixed solution on a 2×6 cm 2 TGPH-060 carbon paper for carbon generation, and use a heating stage to heat the carbon paper during the dropwise coating process. The heating temperature is 80 °C to completely volatilize the acetone. Repeat the dropwise coating-heating process multiple times to ensure that the total dropwise coating amount of the mixed solution on the carbon paper is 250 μL / cm 2 to obtain the carbon paper loaded with the sample;
[0055] Step 3: Fix the carbon paper loaded with the sample in a Joule heating device, evacuate to -0.084 MPa, adjust the input current to 16 A, and apply the current for 10 s to make the reaction temperature between 750 °C and 850 °C, and react to obtain a pure platinum metal catalyst without molybdenum dioxide loading loaded on the surface of the carbon paper.
[0056] Figure 3 Figure for comparing the X-ray diffraction spectra of the molybdenum dioxide-loaded platinum catalyst obtained in Example 1, the pure platinum metal catalyst without molybdenum dioxide loading obtained in Comparative Example 1, and molybdenum dioxide. It can be seen that the molybdenum dioxide-loaded platinum catalyst obtained in Example 1 contains the diffraction peaks of the pure platinum metal catalyst without molybdenum dioxide loading obtained in Comparative Example 1 and molybdenum dioxide.
[0057] Figure 4 Figure for comparing the X-ray photoelectron spectra of the molybdenum dioxide-loaded platinum catalyst obtained in Example 1 and the pure platinum metal catalyst without molybdenum dioxide loading obtained in Comparative Example 1. It can be seen that loading metal platinum particles on the surface of molybdenum dioxide can regulate the surface electronic structure of metal platinum, indicating that there is an interaction between metal platinum and the molybdenum dioxide support.
[0058] Referring to the method of Example 1, using an H-type commercial electrolytic cell, the hydrogen evolution performance of the pure platinum metal catalyst without molybdenum dioxide loading obtained in Comparative Example 1 was tested for electrolytic water.
[0059] Using a Chenhua electrochemical workstation to test the polarization curve performance of the pure platinum metal catalyst without molybdenum dioxide loading obtained in Comparative Example 1, and the test results are as Figure 7As shown, it can be seen that this catalyst achieves a current density of 10 mA / cm² at an overpotential of 23 mV. By comparing with the molybdenum dioxide supported platinum catalyst obtained in Example 1, it can be known that loading metal platinum particles on the surface of molybdenum dioxide can significantly improve the catalytic activity.
[0060] Example 2
[0061] In this example, a molybdenum dioxide supported platinum catalyst was prepared, which specifically included the following steps:
[0062] Step 1: Weigh 16.2 mg of platinum acetylacetonate and 13.5 mg of molybdenum acetylacetonate, place them in a 10 mL glass vial, add 4 mL of acetone solution, and ultrasonically dissolve to obtain a uniform mixed solution;
[0063] Step 2: Dropwise coat the mixed solution on a 2×6 cm 2 TGPH-060 carbon paper for carbon generation, and use a heating stage to heat the carbon paper during the dropwise coating process. The heating temperature is 80 °C to completely volatilize the acetone. Repeat the dropwise coating-heating process multiple times to ensure that the total dropwise coating amount of the mixed solution on the carbon paper is 330 μL / cm 2 to obtain the carbon paper with the supported precursor sample;
[0064] Step 3: Fix the carbon paper with the supported precursor sample in a Joule heating device, evacuate to -0.082 MPa, adjust the input current to 17 A, and apply the current for 10 s to make the reaction temperature between 750 °C and 850 °C, and react to obtain the molybdenum dioxide supported platinum catalyst loaded on the surface of the carbon paper.
[0065] Referring to the method of Example 1, use an H-type commercial electrolytic cell to test the hydrogen evolution performance of the molybdenum dioxide supported platinum catalyst obtained in this example for electrolyzing water.
[0066] Use a Chenhua electrochemical workstation to test the polarization curve performance of the molybdenum dioxide supported platinum catalyst obtained in this example. The test results are as Figure 8 shown, and it can be seen that this catalyst achieves a current density of 10 mA / cm² at an overpotential of 17 mV.
[0067] Example 3
[0068] In this example, a molybdenum dioxide supported platinum catalyst was prepared. The difference in the preparation process compared with Example 2 is only that: adjust the weight of platinum acetylacetonate in Step 1 to 9.76 mg and the weight of molybdenum acetylacetonate to 24.30 mg; the rest of the steps are exactly the same.
[0069] Referring to the method of Example 1, use an H-type commercial electrolytic cell to test the hydrogen evolution performance of the molybdenum dioxide supported platinum catalyst obtained in this example for electrolyzing water.
[0070] The polarization curve performance of the molybdenum dioxide supported platinum catalyst obtained in this example was tested using a Chenhua electrochemical workstation, and the test results are as Figure 9 shown. It can be seen that the catalyst achieves a current density of 10 mA / cm² at an overpotential of 18 mV.
[0071] The above is a detailed introduction to the preparation method and application of a molybdenum dioxide supported platinum catalyst proposed by the present invention. Specific examples are used in this article to elaborate on the principle and implementation mode of the present invention. The description of the above examples is only used to help understand the method and its core idea of the present invention, including the best mode, and also enables any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention. The protection scope of this invention patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements that are not different from the literal description of the claims, or if they include equivalent structural elements that have no substantial difference from the literal description of the claims, then these other embodiments should also be included within the scope of the claims.
Claims
1. A method for preparing a molybdenum dioxide-supported platinum catalyst, characterized in that: The following steps are involved: Step 1, weighing platinum acetylacetonate and molybdenum acetylacetonate, dissolving them in a volatile organic solvent to obtain a uniform mixed solution; Step 2, dripping the mixed solution onto carbon paper, and keeping the carbon paper heated during the dripping process to completely volatilize the organic solvent, repeating the dripping-heating process multiple times to obtain carbon paper loaded with the precursor sample; Step 3: fix the carbon paper loaded with the precursor sample in a Joule heating device, evacuate the device, and react to obtain a molybdenum dioxide-loaded platinum catalyst loaded on the surface of the carbon paper by adjusting the input current and the application time.
2. The method for preparing a molybdenum dioxide-supported platinum catalyst according to claim 1, wherein: In step 1, the molar ratio of platinum acetylacetonate to molybdenum acetylacetonate is 1-3:1-3, and the solute concentration in the mixed solution is 0.02-0.08 mol / L.
3. The method for preparing a molybdenum dioxide-supported platinum catalyst according to claim 1, wherein: The carbon paper in step 2 is raw carbon paper.
4. The method for preparing a molybdenum dioxide-supported platinum catalyst according to claim 1, wherein: After repeating the drip coating-heating process in step 2 for several times, the total drip coating amount of the mixed solution on the carbon paper is ensured to be 250-350 μL / cm 2 .
5. The method for preparing a molybdenum dioxide-supported platinum catalyst according to claim 1, characterized in that: In step 3, the reaction temperature is adjusted to 750° C. to 850° C. by adjusting the input current, and the application time is 10 s.
6. The method for preparing a molybdenum dioxide-supported platinum catalyst according to claim 5, characterized in that: The input current range adjusted in step 3 is 16 to 20A.
7. The method for preparing a molybdenum dioxide-supported platinum catalyst according to claim 1, characterized in that: The mass fraction of metal platinum in the molybdenum dioxide-supported platinum catalyst is 0.4% to 1.12%.
8. Use of the molybdenum dioxide-supported platinum catalyst obtained by the method of any one of claims 1 to 7 in the electrocatalytic electrolysis of water to produce hydrogen.
9. An electrocatalytic water electrolysis hydrogen production device, characterized in that: The conductive substrate loaded with the molybdenum dioxide loaded platinum catalyst obtained by the method of any one of claims 1 to 7 is used as the working electrode.