Mo2tic2 supported platinum catalyst, its preparation method and application
By supporting a platinum catalyst on Mo2TiC2, platinum particles are independently dispersed on the two-dimensional Mo2TiC2 material, which solves the problems of high cost and poor stability of precious metal platinum catalysts in the process of hydrogen production by water electrolysis, and achieves low-cost and high-efficiency hydrogen production by water electrolysis.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-05-31
- Publication Date
- 2026-03-20
AI Technical Summary
Existing precious metal platinum catalysts are costly and unstable in the process of hydrogen production by water electrolysis. They are prone to agglomeration and deactivation, especially at high current densities, making it difficult to achieve low-cost and stable hydrogen production.
A platinum catalyst supported on Mo2TiC2 was used, with platinum particles independently dispersed on the two-dimensional Mo2TiC2 material. The size of the platinum particles ranged from 0.2 to 4.5 nanometers. By controlling the loading and size of platinum, and combining the chemical functional groups of Mo2TiC2 to stabilize platinum ions, uniform dispersion and structural stability of platinum were achieved.
It achieves hydrogen production performance by water electrolysis with an overpotential of less than 20 mV at a current density of 10 mA/s², reducing the amount of platinum used and improving the stability and catalytic efficiency of the catalyst.
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Figure CN116445974B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of nanocatalysts, and particularly relates to a Mo2TiC2 supported platinum catalyst and a preparation method and application thereof. BACKGROUND
[0002] Hydrogen energy is a high-efficiency and clean secondary energy, has high energy density, and the combustion product is only pollution-free water, and is an energy carrier most likely to replace traditional fossil fuels. As of now, 90% of hydrogen sources are obtained by reforming fossil energy, such as coal, petroleum, natural gas and industrial by-product hydrogen, but serious environmental pollution problems will be caused in the preparation process, and a large amount of carbon dioxide gas will be produced, which will aggravate the global greenhouse effect, and is undoubtedly very unfavorable for achieving the "double carbon" emission reduction goal.
[0003] Using renewable energy such as solar energy, wind energy, water energy and other clean energy to prepare "green hydrogen" is a more green and environmentally friendly hydrogen production method. Among them, the method of electrolyzing water to produce hydrogen has the advantages of high purity and small pollution, and is an important direction for the development of hydrogen energy in the future. Platinum is a noble metal with the best performance in the electrolysis of water to produce hydrogen, but the price of platinum is high, which will cause high cost. Therefore, it is crucial to reduce the use of platinum. Single-atom platinum has a large specific surface area due to the full exposure of active sites, and can effectively regulate the selectivity, activity and stability of metal active centers in the catalytic process, greatly reducing the use cost of platinum. However, platinum single atoms have high surface free energy, are easy to agglomerate and deactivate in the catalytic reaction, and are difficult to realize stable hydrogen production at a large current density. Therefore, it is the research goal in the future to realize low-cost stable hydrogen production at a large current density by regulating the size of platinum.
[0004] In addition, the metal-support interaction has an important influence on the catalytic process, so anchoring platinum on a suitable support can significantly improve its catalytic activity and stabilize the structure of platinum. SUMMARY
[0005] In view of the problems of catalyst cost and stability of platinum in the catalytic reaction in the prior art, the application provides a Mo2TiC2 supported platinum catalyst and a preparation method and application thereof, which can maintain the stability of platinum in the catalyst during long-time electrolysis for hydrogen production, and can realize scale production.
[0006] In order to achieve the above purpose, the application provides the following technical scheme:
[0007] A Mo2TiC2 supported platinum catalyst characterized in that it is a Mo2TiC2 two-dimensional material loaded with platinum particles, and the platinum particles are independent of each other; the size of the platinum particles ranges from 0.2 to 4.5 nanometers, and the mass ratio of platinum to Mo2TiC2 is 1:(9-99).
[0008] Further, the Mo2TiC2 supported platinum catalyst with the size of the platinum particles being 1.5-2 nanometers realizes a overpotential of less than 20 millivolts at a current density of 10 milliamperes per square.
[0009] Further, the Mo2TiC2 two-dimensional material is a few-layer or / and single-layer Mo2TiC2, the number of layers is not more than 3, and the morphology is fluffy.
[0010] A Mo2TiC2 supported platinum catalyst characterized in that the preparation process is: etching a precursor Mo2TiAlC2 to obtain a multi-layer Mo2TiC2, and exfoliating the multi-layer Mo2TiC2 to obtain a few-layer or / and single-layer Mo2TiC2; mixing and stirring a platinum precursor with the few-layer or / and single-layer Mo2TiC2 according to a mass ratio of platinum to Mo2TiC2 of 1:(9-99), and after hydrothermal reaction, washing and drying to obtain the Mo2TiC2 supported platinum catalyst.
[0011] A preparation method of a Mo2TiC2 supported platinum catalyst, characterized in that it comprises the following steps:
[0012] Step 1: Take 40% mass fraction of hydrofluoric acid as etching solution, add the precursor Mo2TiAlC2 into the etching solution and stir for etching for 35-65 hours, after which the obtained black ink precipitate is centrifugally washed with argon-saturated deionized water for multiple times, and then the precipitate is freeze-dried at-60℃ to obtain a multi-layer Mo2TiC2 powder;
[0013] Step 2: Add the multi-layer Mo2TiC2 powder into a tetrabutylammonium hydroxide solution and stir for exfoliation at 40-80℃, after which the Mo2TiC2 obtained after centrifugal washing with argon-saturated deionized water for multiple times is added into argon-saturated deionized water again to configure a Mo2TiC2 aqueous solution A with a concentration of 20-30 grams per liter, and then the solution is ice-bathed and ultrasonically treated at a cold trap temperature of-10 to-1℃, after which the upper gel body is centrifugally taken and freeze-dried at-60℃ to obtain a few-layer or / and single-layer Mo2TiC2 powder;
[0014] Step 3: Dissolve the platinum precursor in deionized water to obtain a platinum precursor solution with a concentration of 0.15-0.75 g / L, and dissolve a small layer or / and single layer of Mo2TiC2 powder in deionized water to obtain a Mo2TiC2 aqueous solution B with a concentration of 0.5-3 g / L; according to the mass ratio of platinum to Mo2TiC2 of 1:(9-99), slowly add the platinum precursor solution to the Mo2TiC2 aqueous solution B, stir for 0.5-2 hours, and then hydrothermally react at 80-260 degrees Celsius for 0.5-5 hours; after cooling, centrifugal washing, and vacuum drying, a Mo2TiC2 supported platinum catalyst is obtained.
[0015] Further, in step 1, the mass of the precursor Mo2TiAlC2 and the volume of the hydrofluoric acid are in a ratio of 1:(10-30), with the mass unit being grams and the volume unit being milliliters.
[0016] Further, in step 1, the etching temperature is 25-65 degrees Celsius.
[0017] Further, in step 1, the centrifugal washing speed is 5000-8000 revolutions per minute, the washing time is 5-10 minutes, and the washing number is 3-8 times, with the washing being performed until the solution PH value is 7.
[0018] Further, in step 2, the mass of the multi-layer Mo2TiC2 powder and the volume of the tetrabutylammonium hydroxide solution are in a ratio of 1:(10-50), with the mass unit being grams and the volume unit being milliliters.
[0019] Further, in step 2, the peeling time is 12-36 hours.
[0020] Further, in step 2, the centrifugal washing speed is 6000-11000 revolutions per minute, the washing time is 5-10 minutes, and the washing number is 2-5 times; after ice bath ultrasonic treatment, the centrifugal speed is 1500-5000 revolutions per minute, and the centrifugal time is 30-120 minutes.
[0021] Further, in step 2, the ice bath ultrasonic treatment time is 30-120 minutes, and the ultrasonic power is 200-700 watts.
[0022] Further, in step 3, the platinum precursor is platinum tetraammine nitrate or chloroplatinic acid hexahydrate.
[0023] Further, in step 3, the centrifugal washing speed is 6000-10000 revolutions per minute, the washing time is 5-10 minutes, and the washing number is 2-4 times.
[0024] The application also provides a Mo2TiC2 supported platinum catalyst prepared by the above method or a Mo2TiC2 supported platinum catalyst prepared by any one of the above technical solutions, and the application of the Mo2TiC2 supported platinum catalyst in the electrolytic water hydrogen production of electrocatalysis.
[0025] Compared with the prior art, the application has the following beneficial effects:
[0026] 1、 The Mo2TiC2 supported platinum catalyst provided by the application has low platinum content, the size range of platinum particles is only 0.2-4.5 nanometers, the platinum particles are uniformly dispersed on the surface layer of Mo2TiC2 two-dimensional material, the most ideal loading amount and platinum particle size are realized by regulating the loading concentration of platinum, the preparation method is simple, the cost is low, and the method is suitable for the preparation of a large amount of Mo2TiC2 supported platinum catalysts;
[0027] 2、 The abundant chemical functional groups (-OH, -O, -F, etc.) on the surface of Mo2TiC2 in the application can better stabilize platinum ions, and Mo2TiC2 is helpful to the adsorption and desorption of intermediates (H*) on its surface in the process of electrolytic water hydrogen production; by regulating the etching time of the precursor Mo2TiAlC2, multi-layer Mo2TiC2 powder with different defect concentrations can be obtained, which can better stabilize platinum ions, and further ensure the structural stability of platinum in the catalytic reaction;
[0028] 3、 The Mo2TiC2 supported platinum catalyst has excellent electrolytic water hydrogen production performance, and is applied to a three-electrode system to realize a overpotential of less than 20 millivolts at a current density of 10 milliamperes. BRIEF DESCRIPTION OF DRAWINGS
[0029] Figure 1 It is a scanning electron microscope image of the catalyst carrier multi-layer Mo2TiC2 obtained in Example 1;
[0030] Figure 2 It is a scanning electron microscope image of the catalyst carrier multi-layer Mo2TiC2 obtained in Example 2;
[0031] Figure 3 It is a scanning electron microscope image of the catalyst carrier multi-layer Mo2TiC2 obtained in Example 3;
[0032] Figure 4 It is a scanning transmission electron microscope high-angle annular dark field image of the Mo2TiC2 supported platinum catalyst obtained in Example 5;
[0033] Figure 5 It is a hydrogen evolution current density curve of the Mo2TiC2 supported platinum catalyst obtained in Example 5 in a catalytic electrolytic water hydrogen production reduction reaction at different potentials
[0034] Figure 6 It is a scanning transmission electron microscope dark field image of the Mo2TiC2 supported platinum catalyst obtained in Example 6;
[0035] Figure 7Hydrogen evolution current density curves of the Mo2TiC2 supported platinum catalyst obtained in Example 6 at different potentials in the hydrogen reduction reaction of water electrolysis. DETAILED DESCRIPTION
[0036] In order to further understand the technical effects of the present application, the preferred technical solutions of the present application are described below.
[0037] A Mo2TiC2 supported platinum catalyst is a Mo2TiC2 two-dimensional material loaded with platinum particles, and the platinum particles are independent of each other; the platinum particles are small clusters with a size range of 1.5-2 nanometers, and the mass ratio of platinum to Mo2TiC2 is 1:(9-49), which can achieve a overpotential of less than 20 millivolts at a current density of 10 milliamperes per square.
[0038] A method for preparing the Mo2TiC2 supported platinum catalyst with platinum particles having a size of 1.5-2 nanometers, comprising the following steps:
[0039] Step 1: Take 40% mass fraction of hydrofluoric acid as etching solution, add the precursor Mo2TiAlC2 into the etching solution and stir to etch for 40-60 hours, after the end, centrifugal washing with argon-saturated deionized water for multiple times, the obtained black ink precipitate is freeze-dried at-60℃ to obtain multi-layer Mo2TiC2 powder;
[0040] Step 2: Add the multi-layer Mo2TiC2 powder into tetrabutylammonium hydroxide solution, stir to peel off at 50-60 degrees Celsius, after the end, centrifugal washing with argon-saturated deionized water for 2-3 times, the obtained Mo2TiC2 is added into argon-saturated deionized water again to prepare Mo2TiC2 aqueous solution A with a concentration of 20-30 grams per liter, ice bath ultrasonic at a cold trap temperature of-10 to-1℃, then centrifugal separation to take the upper gelatinous body for-60℃ freeze-drying to obtain few-layer or / and single-layer Mo2TiC2 powder;
[0041] Step 3: Dissolve chloroplatinic acid hexahydrate in deionized water to obtain a platinum precursor solution with a concentration of 0.15-0.65 grams per liter, dissolve the few-layer or / and single-layer Mo2TiC2 powder in deionized water to obtain Mo2TiC2 aqueous solution B with a concentration of 0.5-2 grams per liter; according to the mass ratio of platinum to Mo2TiC2 being 1:(9-49), slowly add the platinum precursor solution into the Mo2TiC2 aqueous solution B, stir for 0.5-2 hours, then hydrothermal reaction at 120-220 degrees Celsius for 0.5-3 hours, after cooling, centrifugal washing and vacuum drying, the Mo2TiC2 supported platinum catalyst is obtained.
[0042] For a further understanding of the present application, the embodiments thereof will be described in conjunction with the following examples, it being understood that the description is merely by way of further illustration of the features and advantages of the application, and not as a limitation thereof. All starting materials of the present application are not particularly limited in their source, and can be purchased on the market or prepared according to conventional methods well known to those skilled in the art.
[0043] Example 1
[0044] In this example, a catalyst carrier multilayer Mo2TiC2 was prepared, and the specific steps were as follows:
[0045] 1 gram of the precursor Mo2TiAlC2 was added into 20 milliliters of hydrofluoric acid etching solution (40% by mass), and stirred and etched at 55°C for 40 hours, with a magnetic stirring speed of 6000 revolutions per minute, to obtain a suspension; deionized water saturated with argon was used for centrifugal cleaning for 6 times until the pH value was 7, with a centrifugal speed of 6000 revolutions per minute each time and a time of 5 minutes; the obtained blackish ink precipitate was freeze-dried at -60°C to obtain a multilayer Mo2TiC2 powder, which was recorded as M-Mo2TiC2-1, and the scanning electron microscope image thereof is shown in Figure 1 .
[0046] Example 2
[0047] In this example, a catalyst carrier multilayer Mo2TiC2 was prepared, and the specific steps were as follows:
[0048] 1 gram of the precursor Mo2TiAlC2 was added into 20 milliliters of hydrofluoric acid etching solution (40% by mass), and stirred and etched at 55°C for 40 hours, with a magnetic stirring speed of 6000 revolutions per minute, to obtain a suspension; deionized water saturated with argon was used for centrifugal cleaning for 6 times until the pH value was 7, with a centrifugal speed of 6000 revolutions per minute each time and a time of 5 minutes; the obtained blackish ink precipitate was freeze-dried at -60°C to obtain a multilayer Mo2TiC2 powder, which was recorded as M-Mo2TiC2-1, and the scanning electron microscope image thereof is shown in Figure 2 .
[0049] Example 3
[0050] In this example, a catalyst carrier multilayer Mo2TiC2 was prepared, and the specific steps were as follows:
[0051] Take 1 gram of precursor Mo2TiAlC2 and add it to 20 milliliters of hydrofluoric acid etching solution (40% by mass) and stir to etch at 55°C for 60 hours with a magnetic stirring speed of 6000 revolutions per minute to obtain a suspension; use argon-saturated deionized water to centrifugally wash 6 times until the pH value is 7, with a centrifugal speed of 6000 revolutions per minute each time and a time of 5 minutes; freeze-dry the ink-black precipitate obtained at -60°C to obtain multi-layer Mo2TiC2 powder, which is denoted as M-Mo2TiC2-3, and the scanning electron microscope image is as shown in Figure 3 .
[0052] According to the scanning electron microscope image shown in Figures 1-3 , it can be seen that M-Mo2TiC2-1 obtained by etching for 40 hours has not completely etched the Al element in Mo2TiAlC2 due to insufficient etching time, and there are still large blocks in the material, which cannot obtain loose multi-layer Mo2TiC2 and will reduce the yield of single-layer Mo2TiC2 in the later stage; M-Mo2TiC2-2 has an appropriate etching time and obtains uniform and loose multi-layer Mo2TiC2, which increases the specific surface area of Mo2TiC2 and improves the yield of single-layer Mo2TiC2 in the later stage; M-Mo2TiC2-3 has a longer etching time, and the obtained multi-layer Mo2TiC2 presents many fragments, which will reduce the quality of single-layer Mo2TiC2 obtained in the later stage and may affect the further loading of platinum particles in the carrier.
[0053] Example 4
[0054] This example prepares a catalyst carrier few-layer or / and single-layer Mo2TiC2, and the specific steps are as follows:
[0055] Take 1 gram of multi-layer Mo2TiC2 powder obtained in Example 2 and add it to 40 milliliters of tetrabutylammonium hydroxide solution (40wt%) and stir to exfoliate at 55°C for 12 hours; after exfoliation, centrifugally wash with argon-saturated deionized water 3 times with a centrifugal speed of 6000 revolutions per minute and a time of 5 minutes; after washing and centrifugation, add the Mo2TiC2 to argon-saturated deionized water again to prepare a Mo2TiC2 aqueous solution A with a concentration of 25 grams per liter, and perform ice bath ultrasonic treatment at a cold trap temperature of -4°C for 60 minutes with an ultrasonic power of 500 watts; after ultrasonic treatment, centrifuge again with a centrifugal speed of 3500 revolutions per minute and a time of 1 hour; take the upper gel body after centrifugation and freeze-dry it at -60°C to obtain few-layer or / and single-layer Mo2TiC2.
[0056] Example 5
[0057] This example prepares a Mo2TiC2-supported platinum catalyst, and the specific steps are as follows:
[0058] 12 mg of platinum tetraamminenitrate was dissolved in 20 mL of deionized water to obtain a platinum precursor solution. 50 mg of the few-layer or / and monolayer Mo₂TiC₂ obtained in Example 4 was dissolved in 50 mL of deionized water to obtain Mo₂TiC₂ aqueous solution B. The platinum precursor solution was slowly added dropwise to Mo₂TiC₂ aqueous solution B, and after stirring for 30 minutes, hydrothermal treatment was performed. The resulting mixed solution was placed in a 40 mL hydrothermal reactor liner and hydrothermally treated at 160 °C for 120 minutes. The obtained product was further washed three times with deionized water by centrifugation at 6000 rpm for 5 minutes each time. The precipitate after centrifugation was vacuum dried for 48 hours to obtain the Mo₂TiC₂ supported platinum catalyst.
[0059] The platinum atomic mass ratio in the Mo2TiC2 supported platinum catalyst obtained in this example was determined to be 2.5% by inductively coupled plasma atomic emission spectrometry, and the average size of the platinum was 0.2 nanometers.
[0060] The high-angle annular dark-field image of the Mo2TiC2 supported platinum catalyst obtained in this embodiment is as follows: Figure 4 As shown, the white dots in the circles are platinum atoms with an average size of 0.2 nanometers, and it can be seen that each platinum atom is isolated from the others.
[0061] The electrochemical catalytic hydrogen evolution performance of the Mo2TiC2 supported platinum catalyst obtained in this embodiment was tested using an H-type three-electrode electrolyzer. Specifically, 4 mg of the Mo2TiC2 supported platinum catalyst was dissolved in a mixture of 300 μL ethanol, 680 μL deionized water, and 20 μL Nafion (a perfluorosulfonic acid polymer). The mixture was sonicated in an ice bath for 30 minutes and then further uniformly dispersed onto a glassy carbon electrode (working electrode) with a surface area of 0.196 cm², with a catalyst loading of 0.5 mg / cm². The counter electrode was a graphite rod, the reference electrode was a saturated calomel electrode, and the electrolytes for both the cathode and anode were 0.5 mol sulfuric acid electrolytes. The ion exchange membrane in the middle of the electrolyzer was a Nafion 117 membrane.
[0062] The performance of the catalyst was tested using the Chenhua electrochemical workstation, and the results are as follows: Figure 5 As shown, a current density of 10 mA can be achieved at an overpotential of 75 mV.
[0063] Example 6
[0064] This embodiment prepares a Mo2TiC2 supported platinum catalyst, and the specific steps are as follows:
[0065] Take 12 milligrams of chloroplatinic acid hexahydrate and dissolve it in 20 milliliters of deionized water to obtain a platinum precursor solution. Take 50 milligrams of the few-layer or / and single-layer Mo2TiC2 obtained in Example 4 and dissolve it in 25 milliliters of deionized water to obtain a Mo2TiC2 aqueous solution. Slowly drop the platinum precursor solution into the Mo2TiC2 aqueous solution, stir for 30 minutes, and then perform hydrothermal treatment. Place the obtained mixed solution into a 40-milliliter hydrothermal reactor inner container, and perform hydrothermal treatment at 200°C for 120 minutes. Further centrifugally wash the obtained product with deionized water three times at a centrifugal speed of 6000 revolutions per minute and a centrifugal time of 5 minutes. Vacuum dry the precipitate after centrifugation for 48 hours to obtain a Mo2TiC2 supported platinum catalyst.
[0066] The atomic mass percentage of platinum in the Mo2TiC2 supported platinum catalyst obtained in this example is 3% as determined by inductively coupled plasma atomic emission spectrometry.
[0067] The scanning transmission electron microscope dark field image of the Mo2TiC2 supported platinum catalyst obtained in this example is shown in FIG. 6, where the white dots in the black circles are platinum clusters with an average size of 1.75 nanometers. It can be seen that each platinum cluster is independent of each other. Figure 6
[0068] The Mo2TiC2 supported platinum single-atom catalyst obtained in this example was tested for its performance in electrochemical catalytic electrolysis of water to produce hydrogen by using an H-type three-electrode electrolysis cell. Specifically, 4 milligrams of the Mo2TiC2 supported platinum single-atom catalyst was dissolved in a mixture of 300 microliters of ethanol, 680 microliters of deionized water, and 20 microliters of nafion, and then subjected to ice-bath ultrasonic treatment for 30 minutes. The catalyst was further uniformly dispersed on a glassy carbon electrode with a surface area of 0.196 square centimeters, and the catalyst loading was 0.5 milligrams per square centimeter. A graphite rod was used as the counter electrode, a saturated calomel electrode was used as the reference electrode, and 0.5 molar sulfuric acid electrolyte was used as the cathode and anode electrolyte. A nafion 117 membrane was used as the ion exchange membrane in the electrolysis cell.
[0069] The polarization curve performance of the catalyst was tested by using a Chenhua electrochemical workstation, and the test results are shown in FIG. 7. It can be seen that a current density of 10 milliamperes can be achieved at a overpotential of less than 20 millivolts. Figure 7
[0070] Example 7
[0071] A Mo2TiC2 supported platinum catalyst was prepared in this example, and the specific steps are as follows:
[0072] Take 12 milligrams of hexahydrate chloroplatinic acid and dissolve it in 20 milliliters of deionized water to obtain a platinum precursor solution. Take 50 milligrams of the few-layer or / and single-layer Mo2TiC2 obtained in Example 4 and dissolve it in 25 milliliters of deionized water to obtain a Mo2TiC2 aqueous solution. Slowly drop the platinum precursor solution into the Mo2TiC2 aqueous solution, stir for 30 minutes, and then perform hydrothermal treatment. Place the obtained mixed solution into a 40-milliliter hydrothermal reactor inner container, and perform hydrothermal treatment at 260°C for 120 minutes. The obtained product is further centrifuged with deionized water for 3 times, with a centrifugal speed of 6000 revolutions per minute and a centrifugal time of 5 minutes. The precipitate after centrifugation is vacuum dried for 48 hours to obtain a Mo2TiC2 supported platinum catalyst.
[0073] The atomic mass percentage of platinum in the Mo2TiC2 supported platinum catalyst obtained in this example is 5% as determined by inductively coupled plasma atomic emission spectrometry, and the average size of the platinum clusters is 4.5 nanometers.
[0074] Example 8
[0075] In this example, a Mo2TiC2 supported platinum catalyst is prepared, and the specific steps are as follows:
[0076] Take 12 milligrams of hexahydrate chloroplatinic acid and dissolve it in 20 milliliters of deionized water to obtain a platinum precursor solution. Take 50 milligrams of the few-layer or / and single-layer Mo2TiC2 obtained in Example 4 and dissolve it in 25 milliliters of deionized water to obtain a Mo2TiC2 aqueous solution. Slowly drop the platinum precursor solution into the Mo2TiC2 aqueous solution, stir for 30 minutes, and then perform hydrothermal treatment. Place the obtained mixed solution into a 40-milliliter hydrothermal reactor inner container, and perform hydrothermal treatment at 260°C for 120 minutes. The obtained product is further centrifuged with deionized water for 3 times, with a centrifugal speed of 6000 revolutions per minute and a centrifugal time of 5 minutes. The precipitate after centrifugation is vacuum dried for 48 hours to obtain a Mo2TiC2 supported platinum catalyst.
[0077] The scanning transmission electron microscope dark field image of the Mo2TiC2 supported platinum catalyst obtained in this example shows that the average size of the platinum clusters is 1.5-2 nanometers.
[0078] Example 9
[0079] In this example, a Mo2TiC2 supported platinum catalyst is prepared, and the specific steps are as follows:
[0080] A platinum precursor solution was prepared by dissolving 0.6 mg of chloroplatinic acid hexahydrate in 3 mL of deionized water. A Mo2TiC2 aqueous solution was prepared by dissolving 10 mg of the few-layer or / and single-layer Mo2TiC2 obtained in Example 4 in 20 mL of deionized water. The platinum precursor solution was slowly added to the Mo2TiC2 aqueous solution. After stirring for 30 minutes, the resulting mixture was subjected to hydrothermal treatment. The mixture was loaded into a 40 mL hydrothermal reactor and subjected to hydrothermal treatment at 220 °C for 30 minutes. The resulting product was further washed by centrifugation three times at 6000 rpm for 5 minutes using deionized water. The precipitate was vacuum dried for 48 hours to obtain a Mo2TiC2 supported platinum catalyst.
[0081] The scanning transmission electron microscopy dark field image of the Mo2TiC2 supported platinum catalyst obtained in this example showed that the average size of the platinum clusters was 1.5-2 nm.
[0082] The principles and implementations of the present application have been described in specific examples. The above examples are only used to help understand the method of the present application and its core idea, including the best mode, and also enable any person skilled in the art to practice the present application, including manufacturing and using any device or system, and implementing any combined method. It should be noted that, for those skilled in the art, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application. The scope of protection of the present application is defined by the claims, and can 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 expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included within the scope of the claims.
Claims
1. A Mo2TiC2 supported platinum catalyst, characterized in that, The material is a two-dimensional Mo2TiC2 material loaded with platinum particles, and the platinum particles are independent of each other; the size of the platinum particles ranges from 0.2 to 4.5 nanometers, and the mass ratio of platinum to Mo2TiC2 is 1:(9 to 99); the two-dimensional Mo2TiC2 material is a few-layer or / and single-layer Mo2TiC2, with no more than 3 layers, and has a fluffy morphology. The preparation method of the Mo2TiC2 supported platinum catalyst includes the following steps: Step 1: Take 40% hydrofluoric acid as the etching solution, add the precursor Mo2TiAlC2 to the etching solution and stir and etch for 35-65 hours. After the etching is completed, centrifuge and wash it multiple times with argon-saturated deionized water. The resulting dark black precipitate is freeze-dried at -60 degrees Celsius to obtain multilayer Mo2TiC2 powder. Step 2: Add the multilayer Mo2TiC2 powder to a tetrabutylammonium hydroxide solution, stir and peel it at 40-80 degrees Celsius, and wash it several times with argon-saturated deionized water by centrifugation. Add the obtained Mo2TiC2 back to argon-saturated deionized water to prepare a Mo2TiC2 aqueous solution A with a concentration of 20-30 g / L. Sonicate the solution in an ice bath at a cold trap temperature of -10 to -1 degrees Celsius, then centrifuge again and freeze-dry the upper colloidal layer at -60 degrees Celsius to obtain multilayer or / and single-layer Mo2TiC2 powder. Step 3: Dissolve the platinum precursor in deionized water to obtain a platinum precursor solution with a concentration of 0.15–0.75 g / L. Dissolve a few-layer or / and monolayer Mo2TiC2 powder in deionized water to obtain a Mo2TiC2 aqueous solution B with a concentration of 0.5–3 g / L. According to the mass ratio of platinum to Mo2TiC2 of 1:(9–99), slowly add the platinum precursor solution dropwise to the Mo2TiC2 aqueous solution B. After stirring for 0.5–2 hours, perform a hydrothermal reaction at 80–260 degrees Celsius for 0.5–5 hours. After cooling, centrifuge, wash, and vacuum dry to obtain the Mo2TiC2 supported platinum catalyst.
2. The Mo2TiC2 supported platinum catalyst according to claim 1, characterized in that, The Mo2TiC2 supported platinum catalyst is a two-dimensional Mo2TiC2 material supported with platinum clusters of 1.5–2 nanometers in size, with a platinum to Mo2TiC2 mass ratio of 1:(9–49). The specific preparation process of the Mo2TiC2 supported platinum catalyst is as follows: Step 1: Take 40% hydrofluoric acid as the etching solution, add the precursor Mo2TiAlC2 to the etching solution and stir and etch for 40-60 hours. After the etching is completed, centrifuge and wash it multiple times with argon-saturated deionized water. The resulting dark black precipitate is freeze-dried at -60 degrees Celsius to obtain multilayer Mo2TiC2 powder. Step 2: Add the multilayer Mo2TiC2 powder to a tetrabutylammonium hydroxide solution and stir and peel it at 50-60 degrees Celsius. After the peeling is completed, centrifuge and wash it 2-3 times with argon-saturated deionized water. Add the obtained Mo2TiC2 to argon-saturated deionized water again to prepare a Mo2TiC2 aqueous solution A with a concentration of 20-30 g / L. Sonicate it in an ice bath at a cold trap temperature of -10 to -1 degrees Celsius. Then centrifuge it again and freeze-dry the upper colloidal layer at -60 degrees Celsius to obtain multilayer or / and single-layer Mo2TiC2 powder. Step 3: Dissolve chloroplatinic acid hexahydrate in deionized water to obtain a platinum precursor solution with a concentration of 0.15–0.65 g / L. Dissolve a few-layer or / and monolayer Mo2TiC2 powder in deionized water to obtain a Mo2TiC2 aqueous solution B with a concentration of 0.5–2 g / L. According to the mass ratio of platinum to Mo2TiC2 1:(9–49), slowly add the platinum precursor solution to the Mo2TiC2 aqueous solution B. After stirring for 0.5–2 hours, perform a hydrothermal reaction at 120–220 degrees Celsius for 0.5–3 hours. After cooling, centrifuge, wash, and vacuum dry to obtain the Mo2TiC2 supported platinum catalyst.
3. The Mo2TiC2 supported platinum catalyst according to claim 1, characterized in that, In step 1, the mass ratio of the precursor Mo2TiAlC2 to the volume ratio of hydrofluoric acid is 1:(10-30), with mass in grams and volume in milliliters; the etching temperature is 25-65 degrees Celsius.
4. The Mo2TiC2 supported platinum catalyst according to claim 1, characterized in that, In step 1, the centrifugation speed is 5000-8000 rpm, the washing time is 5-10 minutes, the washing number is 3-8 times, and the solution pH value is 7.
5. The Mo2TiC2 supported platinum catalyst according to claim 1, characterized in that, In step 2, the mass ratio of the multilayer Mo2TiC2 powder to the volume ratio of the tetrabutylammonium hydroxide solution is 1:(10-50), with mass in grams and volume in milliliters; the peeling time is 12-36 hours.
6. The Mo2TiC2 supported platinum catalyst according to claim 1, characterized in that, In step 2, the centrifugation speed is 6000-11000 rpm, the washing time is 5-10 minutes, and the number of washing cycles is 2-5; the duration of ice bath ultrasonication is 30-120 minutes, and the ultrasonic power is 200-700 watts; after ice bath ultrasonication, the centrifugation speed is 1500-5000 rpm, and the centrifugation time is 30-120 minutes.
7. The Mo2TiC2 supported platinum catalyst according to claim 1, characterized in that, In step 3, the platinum precursor is platinum tetraammine nitrate or chloroplatinic acid hexahydrate; the centrifugal washing speed is 6000-10000 rpm, the washing time is 5-10 minutes, and the number of washing cycles is 2-4.
8. The application of the Mo2TiC2 supported platinum catalyst according to any one of claims 1 to 7 in electrocatalytic water electrolysis for hydrogen production.