Platinum-based amorphous alloy catalytic ribbon for hydrogen evolution catalysis and preparation method thereof

Abstract

The invention relates to the technical field of gas catalysis, in particular to a platinum-based amorphous alloy catalytic ribbon for hydrogen evolution catalysis and a preparation method thereof.The preparation method comprises the following steps that S1, platinum, nickel, copper and phosphorus are mixed according to the mass ratio of 36: 1: 3: 2 and smelted and subjected to suction casting to form an amorphous alloy bar; s2, melting an amorphous alloy bar, spraying the molten amorphous alloy bar to the surface of a rapidly rotating copper roller, and cooling the molten amorphous alloy bar to obtain an as-cast thin strip; s3, the as-cast thin strip is subjected to annealing treatment, and an aged thin strip is obtained; and S4, the aged ribbon is subjected to ultrasonic loading treatment, and the platinum-based amorphous alloy catalytic ribbon is obtained. The platinum-based amorphous alloy catalytic ribbon for hydrogen evolution catalysis prepared by the invention has many active sites and stable catalytic performance. And the preparation process is simple in requirement, short in preparation time, high in repeatability and suitable for large-scale production.

Description

Technical Field

[0001] The invention relates to the technical field of gas catalysis, and in particular to a platinum-based amorphous alloy catalytic thin strip for hydrogen evolution catalysis and a preparation method thereof. Background Art

[0002] As a clean energy with high energy density, sustainability and environmental protection, hydrogen is widely regarded as a preferred alternative to traditional fossil fuels. Among hydrogen production technologies, electrochemical water splitting technology is regarded as one of the most promising hydrogen energy production technologies due to its unique advantages in the energy conversion process. This technology is expected to achieve true "zero emissions" by constructing a cyclic energy conversion system with "water", "hydrogen" and "oxygen" as the core. However, the large-scale application of this technology faces a major challenge, that is, the need to develop efficient electrocatalysts to reduce the high overpotential of the hydrogen evolution reaction (HER) and accelerate the reaction rate.

[0003] At present, conventional methods for preparing high-efficiency electrocatalysts, such as electrochemical deposition, hydrothermal / solvothermal synthesis, and chemical water bath deposition, have achieved certain results in molecular modification, but have defects such as complex process flow, high requirements for multi-step processing, and difficulty in repeatability. These shortcomings limit the large-scale preparation and application of high-efficiency electrocatalysts. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a platinum-based amorphous alloy catalytic thin strip for hydrogen evolution catalysis and a preparation method thereof.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0006] On the one hand, a method for preparing a platinum-based amorphous alloy catalytic strip for hydrogen evolution catalysis is provided, which comprises the following steps:

[0007] S1, mixing platinum, nickel, copper and phosphorus in a mass ratio of 36:1:3:2 and melting and suction casting to form an amorphous alloy rod;

[0008] S2, melting the amorphous alloy rod, spraying it onto the surface of a rapidly rotating copper roller for cooling, and obtaining a cast thin strip;

[0009] S3, annealing the as-cast thin strip to obtain an aged thin strip;

[0010] S4. The aged thin strip is subjected to ultrasonic loading treatment to obtain a platinum-based amorphous alloy catalytic thin strip.

[0011] Furthermore, in step S2, the rotation speed of the copper roller is 3000 r / min.

[0012] Furthermore, in step S3, the annealing temperature is 223° C. and the annealing time is 3 h.

[0013] Furthermore, in step S4, the frequency of ultrasonic loading is 20000 Hz, the triggering pressure is 50 N, the loading energy is 50 J, and the loading time is 1 s.

[0014] On the other hand, a platinum-based amorphous alloy catalytic thin strip for hydrogen evolution catalysis prepared by the above method is provided, wherein the composition is Pt 57.5 Cu 14.7 Ni 5.3 P 22.5 .

[0015] Furthermore, it is a rectangular thin strip with a diameter of 10-20 mm, a width of 2 mm, and a thickness of 30 μm.

[0016] The beneficial effects of the present invention are:

[0017] 1. Firstly, annealing treatment is performed, and then ultrasonic loading treatment is performed to obtain a platinum-based amorphous alloy catalytic ribbon. Ultrasonic loading treatment after annealing can effectively increase the surface energy of the platinum-based amorphous alloy catalytic ribbon and improve the reaction efficiency.

[0018] 2. The process requirements are simple, the preparation time is short, the repeatability is strong, and it is suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a flow chart of a method for preparing a platinum-based amorphous alloy catalytic thin strip according to an embodiment of the present invention;

[0020] Figure 2 is a SEM image of a platinum-based amorphous alloy catalytic ribbon prepared in an embodiment of the present invention;

[0021] Figure 3 is a TEM image of a platinum-based amorphous alloy catalytic ribbon prepared in an embodiment of the present invention;

[0022] Figure 4 is an X-ray diffraction diagram of a platinum-based amorphous alloy catalytic ribbon prepared in an embodiment of the present invention;

[0023] Figure 5 is a curve obtained by differential scanning calorimetry of the platinum-based amorphous alloy catalytic ribbon prepared in an embodiment of the present invention;

[0024] Figure 6 This is a linear sweep voltammetry scan of the platinum-based amorphous alloy catalytic thin strip prepared in an embodiment of the present invention in a 1M KOH solution and a saturated nitrogen atmosphere (compared with a platinum-carbon catalyst);

[0025] Figure 7It is the Tafel curve of the platinum-based amorphous alloy catalytic thin strip prepared in the embodiment of the present invention in 1M KOH solution and saturated nitrogen atmosphere (compared with the platinum-carbon catalyst). DETAILED DESCRIPTION

[0026] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0027] Reference Figure 1 This embodiment provides a method for preparing a platinum-based amorphous alloy catalytic thin strip for hydrogen evolution catalysis, comprising the following steps:

[0028] S1. Platinum (Pt), copper (Cu), nickel (Ni), and phosphorus (P) are precisely mixed in a mass ratio of 36:3:1:2, and an amorphous alloy rod is prepared by a smelting suction casting technique. The specific steps are as follows:

[0029] Platinum, nickel and copper are placed in the copper chamber of the WK series vacuum arc furnace in descending order of melting point. A mechanical pump is used to evacuate the furnace chamber to a vacuum of 5 Pa or below, and then the molecular pump is started to further increase the vacuum to 3×10 - 3 Pa. After completing the vacuum preparation, argon gas is introduced as the protective gas, and the arc gun is moved to the designated position.

[0030] Adjust the arc current to 70-120A, heat the copper cavity, and make the platinum, nickel and copper completely melt and evenly fuse to form a master alloy. After the master alloy is cooled, it is put into a test tube together with phosphorus weighed in proportion, and the tube is sealed using the Hefei Paquin station tube sealing machine.

[0031] When sealing the tube, place the test tube on the tube sealing machine at an angle of 15° and rotate it at a speed of 10 rpm. After the inside of the test tube is evacuated to a vacuum state below 5 Pa using a mechanical pump, the mouth of the test tube is sealed using a Hefei Compaine water-fuel hydrogen-oxygen machine at a flow rate of 200-300 L / h.

[0032] The sealed test tube was installed on the vacuum quenching spray casting machine, and the vacuum degree in the cavity was pumped to below 5Pa using a mechanical pump. Then the molecular pump was started to evacuate the cavity until the vacuum degree reached 3×10-3Pa. Argon was then introduced as a protective gas. When the pressure in the cavity rose to 2×10 2Pa. Then repeat the mechanical pump vacuuming, molecular pump vacuuming and argon purge steps 2-3 times to ensure the ideal working environment in the system. Then turn on the electromagnetic induction melting system, adjust the current to 25A, and control the sample to slowly pass through the purification powder from top to bottom through the pedal to ensure that no bubbles are generated. This process ensures that the phosphorus element is evenly distributed and completely integrated into the alloy matrix to achieve full purification.

[0033] Subsequently, the processed alloy is stacked again in the copper chamber of the WK series vacuum arc furnace, and the vacuuming, protective gas and arc melting steps are repeated to ensure uniform melting of the raw materials.

[0034] S2. Carefully take the amorphous alloy out of the electric arc furnace and quickly place it in the cavity of the vacuum quenching strip spinning machine. Start the vacuum pump to evacuate the cavity until the internal vacuum reaches 3×10 - 3Pa or less. After the vacuum is completed, high-purity argon is filled in as a protective gas in the subsequent melting and strip throwing process. The mother ingot is heated by an induction heating device to melt it quickly into a completely liquid state.

[0035] After the mother ingot is completely melted, the molten metal liquid is sprayed at high speed to the surface of the copper roller with a rotation speed of 3000r / min for cooling by air pressure. Under the action of the high-speed rotating copper roller, the molten metal solidifies rapidly to form an amorphous alloy ribbon (original cast ribbon). The prepared amorphous alloy ribbon has a uniform thickness of 0.03mm and has good dimensional stability and processing performance.

[0036] S3, annealing the obtained original cast thin strip at 223° C. for 3 h to obtain an aged thin strip;

[0037] S4. Place the aged ribbon into a special mold (which has the same function as a conventional mold, acting as a limiter to prevent the ribbon from moving during ultrasonic loading; the mold is made of stainless steel, with a length of 20 mm and a width of 8 mm), and use a special ultrasonic punch (the punch is customized for the ultrasonic machine, suitable for a frequency of 20,000 Hz. The punch is in contact with the ribbon. Under the action of 20,000 Hz ultrasonic waves, the punch generates high-frequency vibrations that act on the sample. Different frequencies of ultrasound correspond to different punches. In this embodiment, the ultrasonic punch is made of titanium alloy, has a rectangular shape, a length of 19.5 mm, and a width of 7.5 mm) for ultrasonic loading treatment. The frequency of ultrasonic loading is 20,000 Hz, the trigger pressure is 50 N, the loaded energy is 50 J, and the loading time is 1 s to obtain a platinum-based amorphous alloy catalytic ribbon.

[0038] The platinum-based amorphous alloy catalytic ribbon prepared in this embodiment is a rectangular ribbon with a diameter of 10-20 mm, a width of 2 mm, and a thickness of 30 μm. Its composition is Pt 57.5 Cu 14.7Ni 5.3 P 22.5 .

[0039] The SEM image of the platinum-based amorphous alloy catalytic ribbon prepared in the embodiment of the present invention is as follows: Figure 2 As shown in the figure, it can be seen that after ultrasonic loading, a layered wrinkled structure is formed, which increases the active area of ​​the reaction.

[0040] The TEM (transmission electron microscope) image of the platinum-based amorphous alloy catalytic ribbon prepared in the embodiment of the present invention is as follows: Figure 3 As shown in the figure, we can see that most of the atoms are disordered and in an amorphous phase, while it also contains a small amount of crystalline phase.

[0041] The X-ray diffraction pattern of the platinum-based amorphous alloy catalytic ribbon prepared in the embodiment of the present invention is as follows: Figure 4 As shown in the figure, it can be seen that the prepared platinum-based amorphous alloy catalytic thin strip still maintains the amorphous characteristics.

[0042] The platinum-based amorphous alloy catalytic ribbon prepared in the embodiment of the present invention has a curve obtained by differential scanning calorimetry, as shown in FIG. Figure 5 As shown in the figure, it can be seen that ultrasonic loading can increase the energy of the aged thin strip.

[0043] The platinum-based amorphous alloy catalytic ribbon prepared in the embodiment of the present invention was used for testing the catalytic effect of the hydrogen evolution reaction (HER) in the electrolysis of water. A standard three-electrode system was used, with a silver-silver chloride electrode as the reference electrode, a graphite rod electrode as the counter electrode, and a stainless steel electrode clamp to clamp the platinum-based amorphous alloy catalytic ribbon as the working electrode. The electrolyte was a 1M potassium hydroxide solution. A Chenhua CHI760 electrochemical workstation was used to test the catalytic performance of the hydrogen evolution reaction (HER) in the electrolysis of water by linear sweep voltammetry in a saturated nitrogen atmosphere. The scan rate in the linear sweep voltammetry test was 5mv / s. Figure 6 As shown, compared with commercial platinum-carbon catalyst and cast ribbon (without any treatment), the platinum-based amorphous alloy catalytic ribbon achieved 10 mA / cm in 1 M potassium hydroxide solution. 2 The overpotential required for the current density is low, which proves that the platinum-based amorphous alloy catalytic ribbon has a significant catalytic effect on the hydrogen evolution reaction. Figure 7 As shown in Figure 2, the Tafel slope of the platinum-based amorphous alloy catalytic ribbon reaches 20.01 mV / dec, which is lower than the 47.88 mV / dec of the cast ribbon. The lower the Tafel slope, the faster the reaction kinetics and the better the catalytic performance.

[0044] In summary, the platinum-based amorphous alloy catalytic thin strip for hydrogen evolution catalysis prepared by the present invention has multiple active sites, stable catalytic performance, simple process requirements, short preparation time, strong repeatability, and is suitable for large-scale production.

[0045] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0046] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing a platinum-based amorphous alloy catalytic thin strip for hydrogen evolution catalysis, characterized in that: The following steps are involved: S1, mixing platinum, nickel, copper and phosphorus in a mass ratio of 36:1:3:2 and smelting and suction casting to form an amorphous alloy rod; S2, melting the amorphous alloy rod, spraying it onto the surface of a rapidly rotating copper roller for cooling, and obtaining a cast thin strip; S3, annealing the as-cast thin strip to obtain an aged thin strip; S4. The aged thin strip is subjected to ultrasonic loading treatment to obtain a platinum-based amorphous alloy catalytic thin strip.

2. The method for preparing a platinum-based amorphous alloy catalytic thin strip for hydrogen evolution catalysis according to claim 1, characterized in that: In step S2, the rotation speed of the copper roller is 3000 r / min.

3. The method for preparing a platinum-based amorphous alloy catalytic thin strip for hydrogen evolution catalysis according to claim 1, characterized in that: In step S3, the annealing temperature is 223° C. and the annealing time is 3 hours.

4. The method for preparing a platinum-based amorphous alloy catalytic thin strip for hydrogen evolution catalysis according to claim 1, characterized in that: In step S4, the frequency of ultrasonic loading is 20000 Hz, the triggering pressure is 50 N, the loading energy is 50 J, and the loading time is 1 s.

5. A platinum-based amorphous alloy catalytic thin strip for hydrogen evolution catalysis prepared by the method according to any one of claims 1 to 4, characterized in that: Its composition is Pt 57.5 Cu 14.7 Ni 5.3 P 22.5 .

6. The platinum-based amorphous alloy catalytic thin strip for hydrogen evolution catalysis according to claim 5, characterized in that: It is a rectangular thin strip with a diameter of 10-20 mm, a width of 2 mm and a thickness of 30 μm.

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