Surface modification method and device for improving catalytic activity of metal material, metal catalytic material prepared by method and application of metal catalytic material

Abstract

The invention provides a surface modification method and device for improving the catalytic activity of a metal material, the metal catalytic material and application of the metal catalytic material. The surface modification method for improving the catalytic activity of the metal material comprises the steps that the metal material is provided; surface mechanical grinding treatment is applied to the surface of the metal material, and the surface mechanical grinding treatment comprises the steps that shock waves are generated through a vibration generator to drive balls to impact the metal material, so that the surface of the metal material is modified, and the catalytic activity of the metal material is improved. In the embodiment of the invention, the metal catalytic material subjected to surface mechanical grinding treatment has very high catalytic activity and good catalytic stability, and can be applied to an alkaline electrolytic bath and an anion exchange membrane electrolytic bath, so that the water electrolysis hydrogen production efficiency is greatly improved, and water electrolysis hydrogen production under high current density is realized.

Description

Technical Field

[0001] This invention relates to the field of material surface modification technology, and in particular to a method and apparatus for surface modification to improve the catalytic activity of metallic materials, the metallic catalytic materials prepared by the method, and their uses. Background Technology

[0002] Hydrogen, due to its high gravimetric energy density and clean combustion characteristics, is an important energy carrier for sustainable energy development. Utilizing renewable energy sources such as wind and solar power for hydrogen production via water electrolysis can achieve net-zero carbon emissions. Currently, the most mature technology in the water electrolysis hydrogen production industry is alkaline water electrolysis, which is relatively mature, has low production costs, and has achieved large-scale commercial application. The electrodes and catalysts in alkaline water electrolysis widely utilize inexpensive and highly stable metal meshes. With the rapid development of the green hydrogen industry, rapid hydrogen production at high current densities is the future direction of the industry. However, the low activity of catalysts in alkaline water electrolysis tanks has become a key technological bottleneck restricting the development of hydrogen energy. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a surface modification method and apparatus for improving the catalytic activity of metal materials, a metal catalytic material prepared by the method and its application, so as to meet the requirements of alkaline water electrolysis tanks for high catalytic activity and high catalytic stability of catalytic materials.

[0004] To achieve the above objectives, the present invention provides a surface modification method for improving the catalytic activity of metallic materials, comprising:

[0005] Provide metal materials;

[0006] The surface mechanical polishing treatment is applied to the surface of the metal material, wherein the surface mechanical polishing treatment includes: generating oscillation waves through a vibration generator to drive a ball to impact the metal material, thereby modifying the surface of the metal material to improve the catalytic activity of the metal material.

[0007] Optionally, the metal material is any one of nickel, iron, cobalt, copper, titanium, nickel alloy, iron alloy, cobalt alloy, copper alloy, and titanium alloy.

[0008] Optionally, the metal material is a mesh metal, a plate metal, or a tubular metal.

[0009] Optionally, the sphere is a ceramic sphere or a metal sphere.

[0010] Optionally, the metal ball may be a nickel ball, iron ball, copper ball, titanium ball, nickel alloy ball, iron alloy ball, cobalt alloy ball, copper alloy ball, or titanium alloy ball.

[0011] Optionally, the surface of the metal material after the surface mechanical grinding treatment will undergo deformation, microstructure changes, and residual stress.

[0012] Optionally, the surface of the metal material after the surface mechanical polishing treatment includes nanocrystals, and the grain size of the metal material after the surface mechanical polishing treatment gradually increases from the surface to the interior, thus forming a gradient structure of nanocrystals and non-nanocrystals in the metal material.

[0013] Optionally, the vibration generator is specifically an ultrasonic generator, which includes an ultrasonic power supply, an ultrasonic transducer, and an ultrasonic amplitude transformer connected to the ultrasonic transducer. In the step of driving the ball to impact the metal material through the vibration generator, the ultrasonic transducer converts the electrical signal generated by the ultrasonic power supply into an oscillation wave, the ultrasonic amplitude transformer emits the oscillation wave, and the oscillation wave emitted by the ultrasonic amplitude transformer drives the ball to move in the reflection chamber and impact the metal material located in the reflection chamber.

[0014] Optionally, the ultrasonic power supply has a power of 1 kW to 10 kW.

[0015] Optionally, the distance between the surface of the metal material and the ultrasonic amplitude transformer is 5 mm to 100 mm.

[0016] Optionally, the diameter of the sphere is 0.5 mm to 5 mm.

[0017] Optionally, the metal material is in an annealed state or has not undergone heat treatment.

[0018] This application also provides a surface modification device for improving the catalytic activity of metal materials, including a sample stage, a reflective chamber, a sphere, and a vibration generator. The sample stage is used to place the metal material and is disposed in the reflective chamber. The sphere is movably disposed in the reflective chamber. The vibration generator is used to generate oscillation waves to drive the sphere to move in the reflective chamber and impact the metal material on the sample stage.

[0019] Optionally, the metal material is any one of nickel, iron, cobalt, copper, titanium, nickel alloy, iron alloy, cobalt alloy, copper alloy, and titanium alloy; the metal material is a mesh metal, a plate metal, or a tubular metal; and the sphere is a ceramic sphere or a metal sphere.

[0020] Optionally, the vibration generator is specifically an ultrasonic generator, which includes an ultrasonic power supply, an ultrasonic transducer, and an ultrasonic amplitude transformer connected to the ultrasonic transducer. The ultrasonic transducer is used to convert the electrical signal generated by the ultrasonic power supply into an oscillation wave, and the ultrasonic amplitude transformer is used to emit the oscillation wave. The oscillation wave emitted by the ultrasonic amplitude transformer is used to drive the sphere to move in the reflection chamber.

[0021] Optionally, the distance between the surface of the metal material and the ultrasonic amplitude transformer is 5 mm to 100 mm; the diameter of the sphere is 0.5 mm to 5 mm; and the power of the ultrasonic power supply is 1 kW to 10 kW.

[0022] In another aspect, this application also provides a metal catalytic material prepared by the above-described surface modification method for improving the catalytic activity of metal materials.

[0023] Optionally, the surface of the metal catalytic material comprises nanocrystals.

[0024] Optionally, the metal catalytic material has a gradually increasing grain size from the surface to the interior, and the metal catalytic material constitutes a gradient structure composed of nanocrystals and non-nanocrystals.

[0025] In another aspect, this application provides the use of a metal catalytic material prepared according to the above-described surface modification method for improving the catalytic activity of metal materials in the electrolysis of water to produce hydrogen.

[0026] The surface modification method and apparatus for improving the catalytic activity of metal materials in this application produce metal catalytic materials with high catalytic activity and good catalytic stability. These materials can be applied in alkaline electrolyzers and anion exchange membrane electrolyzers, significantly improving the efficiency of hydrogen production from water electrolysis and enabling hydrogen production from water electrolysis at high current densities. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic flowchart of a surface modification method for improving the catalytic activity of metallic materials, provided in an embodiment of this application.

[0029] Figure 2 for Figure 1 The diagram shows a schematic of the equipment used in the surface modification method to improve the catalytic activity of metallic materials.

[0030] Figure 3 Scanning electron microscope image of a nickel sheet that has not undergone surface mechanical polishing.

[0031] Figure 4 This is a scanning electron microscope image of a nickel sheet after surface mechanical polishing.

[0032] Figure 5 Electron backscatter diffraction image of a nickel sheet that has not undergone surface mechanical polishing.

[0033] Figure 6 This is an electron backscatter diffraction image of a nickel sheet after surface mechanical polishing.

[0034] Figure 7 LSV curves of hydrogen evolution reaction of untreated nickel sheet, treated nickel sheet, platinum sheet, and Raney nickel in 1.0 M KOH solution.

[0035] Figure 8 The catalytic stability test curve of nickel sheets after surface mechanical polishing in 1.0M KOH solution for hydrogen evolution reaction is shown.

[0036] Figure 9 Catalytic stability test curves of nickel sheets without surface mechanical polishing in 1.0M KOH solution for hydrogen evolution reaction.

[0037] Figure 10 For nickel sheets that have undergone surface mechanical polishing, at 5000 mA cm -2 Catalytic stability test curves of hydrogen evolution reaction under ultra-high current density.

[0038] Figure 11 For nickel sheets that have undergone surface mechanical polishing, the 5000 mA cm-coating test is performed after 3000 hours. -2 The LSV curves before and after the stability test at the current density are compared.

[0039] Explanation of reference numerals in the attached figures:

[0040] 10. Nickel sheet; 11. Sample stage; 12. Reflection chamber; 14. Ferroalloy ball; 16. Ultrasonic generator. Detailed Implementation

[0041] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. Based on the description of the present invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.

[0042] Unless otherwise specified, all test materials and reagents used in the following examples are commercially available.

[0043] Unless otherwise specified in the embodiments, the techniques or conditions described in the literature in this field or in accordance with the product manual may be followed.

[0044] Please refer to Figure 1 This application provides a surface modification method for improving the catalytic activity of metallic materials, comprising the following steps:

[0045] S11 provides metallic materials.

[0046] S13, applying surface mechanical polishing (SMAT) to the surface of the metal material, wherein the surface mechanical polishing includes: generating oscillation waves using a vibration generator to drive a ball to impact the metal material, thereby modifying the surface of the metal material and improving its catalytic activity. After step S13, a metal catalytic material is obtained.

[0047] The metal catalytic material prepared according to the method of this embodiment has high catalytic activity and good catalytic stability in the electrolysis of water to produce hydrogen. It can be applied in alkaline electrolyzers and anion exchange membrane electrolyzers, which can significantly improve the efficiency of water electrolysis to produce hydrogen and realize water electrolysis to produce hydrogen at high current density.

[0048] In some embodiments, the metal material provided in step S11 may be any one of nickel, iron, cobalt, copper, and titanium, or any one of nickel alloy, iron alloy, cobalt alloy, copper alloy, and titanium alloy.

[0049] In some embodiments, the metal material provided in step S11 may be mesh metal, plate metal, or tubular metal.

[0050] In some embodiments, the metal material provided in step S11 is in an annealed state or has not undergone heat treatment before the surface mechanical grinding treatment is applied.

[0051] In some embodiments, the sphere in step S13 may be a ceramic sphere or a metal sphere. Specifically, the metal sphere may be a nickel sphere, an iron sphere, a copper sphere, a titanium sphere, a nickel alloy sphere, an iron alloy sphere, a cobalt alloy sphere, a copper alloy sphere, or a titanium alloy sphere.

[0052] In some embodiments, in step S13, the surface of the metal material after surface mechanical polishing undergoes deformation, microstructure changes, and residual stress. Specifically, the surface of the metal material after surface mechanical polishing includes nanocrystals. More specifically, the grain size of the metal material after surface mechanical polishing gradually increases from the surface to the interior, forming a gradient structure composed of nanocrystals and non-nanocrystals (that is, the content of nanocrystals decreases and the content of non-nanocrystals increases from the surface to the interior of the metal material). The size of the nanocrystals is on the nanometer scale (e.g., the size is greater than 1 nm and less than 1000 nm). Furthermore, surface mechanical polishing introduces lattice defects and strain into the surface of the metal material, which can significantly modulate the physicochemical characteristics of the metal material.

[0053] In some embodiments, in step S13, the vibration generator may specifically be an ultrasonic generator. The ultrasonic generator includes an ultrasonic power supply, an ultrasonic transducer, and an ultrasonic amplitude transformer connected to the ultrasonic transducer. In the step of driving the ball to impact the metal material through the vibration generator, the ultrasonic transducer converts the electrical signal generated by the ultrasonic power supply into an oscillation wave, the ultrasonic amplitude transformer emits an oscillation wave, and the oscillation wave emitted by the ultrasonic amplitude transformer drives the ball to move in the reflection chamber and impact the metal material located in the reflection chamber.

[0054] Specifically, in step S13, the energy of the sphere and the impact level between the sphere and the metal material can be changed by adjusting the ultrasonic power supply, thereby altering the degree of processing, microstructure, and residual stress strain of the metal material, ultimately affecting its catalytic performance. Specifically, the ultrasonic power supply can be from 1 kW to 10 kW.

[0055] Specifically, in step S13, the energy of the sphere and the degree of impact between the sphere and the metal material can be changed by adjusting the distance between the metal material and the ultrasonic amplitude transformer, thereby altering the degree of processing, microstructure, and residual stress strain of the metal material, ultimately affecting its catalytic performance. Specifically, the distance between the surface of the metal material and the ultrasonic amplitude transformer can be from 5 mm to 100 mm.

[0056] Specifically, in step S13, the degree of treatment, microstructure, and residual stress strain of the metal material can be altered by adjusting the time of surface mechanical grinding, thereby ultimately affecting the catalytic performance of the metal material. Specifically, the diameter of the sphere can be from 0.5 mm to 5 mm.

[0057] The present application will be further described below with reference to specific embodiments.

[0058] Example 1

[0059] A surface modification method for improving the catalytic activity of metallic materials includes the following steps:

[0060] The pure nickel sheet (purity up to 99.9%) is annealed at 500 degrees Celsius for one hour. Then, please refer to... Figure 2 A 1 mm thick nickel sheet 10 is placed on a sample stage 11, which is then fixed to the top of a reflective chamber 12. The distance between the surface of the nickel sheet 10 and the ultrasonic amplitude transformer is 5 mm to 100 mm. An iron alloy ball (specifically, 304 stainless steel) 14 with a diameter of 0.5 mm to 5 mm is placed in the reflective chamber 12. The power of the ultrasonic generator 16 is adjusted to 1 kW to 10 kW, and the nickel sheet 10 is mechanically ground. Following the mechanical grinding, the nickel sheet 10 is ultrasonically cleaned sequentially with acetone, anhydrous ethanol, and deionized water for 10 minutes. Finally, the nickel sheet 10 is allowed to air dry naturally for use as a catalyst in water electrolysis.

[0061] The aforementioned surface mechanical polishing technique can process large-area samples and can directly replace the nickel mesh used in existing alkaline electrolytic cells. This technique has a high degree of compatibility with existing industrial technologies. Furthermore, the nickel metal catalyst material prepared by this method has a low cost, only half that of the commercial catalyst Raney nickel, and thus has high commercial value.

[0062] Electrochemical experiments were conducted on the nickel sheet used as a catalyst for water electrolysis to test its electrocatalytic performance. Specifically, a three-electrode system was used to test the electrocatalytic performance of the nickel sheet after the above-mentioned surface mechanical polishing treatment. The electrochemical workstation model was CHI 660E. In the three-electrode electrochemical cell, the nickel sheet after the above-mentioned surface mechanical polishing treatment was used as the working electrode, the carbon rod as the counter electrode, the Hg / HgO electrode as the reference electrode in the alkaline electrolyte, and 1.0M KOH solution as the electrolyte. The scan rate of the linear sweep voltammetry (LSV curve) was 5mV / s, and all LSV curves were compensated for 85% ohmic drop.

[0063] Figure 3 Scanning electron microscope image of a nickel sheet that has not undergone surface mechanical polishing; Figure 4 This is a scanning electron microscope image of a nickel sheet after surface mechanical polishing. Please refer to... Figure 3 and Figure 4 The surface of the nickel sheet that has not undergone surface mechanical polishing is smooth and has slight scratches caused by polishing; the surface of the nickel sheet that has undergone surface mechanical polishing is rough and has dense concave surfaces caused by the impact of a ball.

[0064] Figure 5 Electron backscatter diffraction image of a nickel sheet that has not undergone surface mechanical polishing; Figure 6 This is an electron backscatter diffraction image of a nickel sheet after surface mechanical polishing. Figure 5 and Figure 6 It can display the cross-sectional microstructure information of nickel sheets without surface mechanical polishing and nickel sheets with surface mechanical polishing, respectively. Figure 5 and Figure 6 The image on the right shows a surface microscopic view of the nickel sheet, while the image on the left shows an internal microscopic view. Please refer to the image. Figure 5 and Figure 6 The overall grain size of the untreated nickel sheet is relatively uniform, with large grains, all of which are micron-sized, and the grains with a wide size distribution are about 2 to 50 microns. The area near the surface of the treated nickel sheet is composed of nano-sized grains (i.e., nanocrystals), with a grain size of about 100 to 200 nanometers. The grain size gradually increases from the surface to the interior, with the interior grain size being 2 to 5 microns. It can be seen that the nickel sheet treated with surface mechanical polishing has a clear gradient structure of nanocrystals and micron-sized grains.

[0065] Figure 7 The LSV curves for the hydrogen evolution reaction of untreated nickel sheets, mechanically treated nickel sheets, platinum sheets, and Raney nickel in 1.0 M KOH solution are shown. Please refer to... Figure 7 The nickel sheet, after surface mechanical polishing, exhibits significantly enhanced catalytic activity for the hydrogen evolution reaction at 10 mA cm⁻¹. -2 The hydrogen evolution overpotential at the current density decreases from 207 mV to 105 mV when the current density is greater than 45 mA cm⁻¹. -2 At this time, the catalytic activity of nickel sheets after surface mechanical polishing is superior to that of Raney nickel and platinum sheets; especially when the current density is higher than 100 mA cm⁻¹. -2 At that time, the catalytic activity of nickel sheets after surface mechanical polishing was significantly higher than that of Raney nickel, platinum sheets, and untreated nickel sheets. Both alkaline electrolytic cells and anion exchange membrane electrolytic cells exhibited catalytic activity above 100 mA cm⁻¹. -2 Because it operates within a specific current range, surface-mechanically ground nickel sheets have significant application potential in alkaline electrolyzers and anion exchange membrane electrolyzers, and can also greatly improve hydrogen production efficiency. Please refer to Table 1 below for a comparison of the performance of untreated nickel sheets, surface-mechanically ground nickel sheets, platinum sheets, and Raney nickel in the hydrogen evolution reaction. For example, when the current density is higher than 100 mA cm⁻¹... -2 At that time, the overpotential of the nickel sheet after surface mechanical polishing in the hydrogen evolution reaction of water electrolysis was 262mV, which is better than that of commercial catalysts Raney nickel (425mV) and platinum sheet (359mV).

[0066] Table 1

[0067]

[0068] Figure 8 The catalytic stability test curve of nickel sheets after surface mechanical polishing in 1.0M KOH solution for hydrogen evolution reaction is shown. Figure 9 The catalytic stability test curves for the hydrogen evolution reaction of untreated nickel sheets in 1.0 M KOH solution are shown. Please refer to... Figure 8 Apply 500 mA cm to the nickel sheet after surface mechanical polishing. -2 Stability tests were conducted using a specific current density. After 100 hours, the catalytic performance of the nickel sheet, which had undergone surface mechanical polishing, showed no decline, indicating high catalytic stability. Please refer to... Figure 9 Apply 100 mA cm to a nickel sheet that has not undergone surface mechanical polishing. -2 Stability tests were conducted on the current density. In less than 10 hours, the voltage increased significantly. After more than 20 hours, the voltage increased by 91mV. It can be seen that the voltage increases with time, indicating that its catalytic activity continuously decreases and its catalytic stability is poor.

[0069] Figure 10 For nickel sheets that have undergone surface mechanical polishing, at 5000 mA cm -2 Catalytic stability test curves for the hydrogen evolution reaction at ultra-high current densities. Please refer to... Figure 10 Apply 5000 mA cm to the nickel sheet after surface mechanical polishing. -2 The voltage remained basically the same as the initial voltage after 3000 hours, indicating that it has high catalytic stability.

[0070] Figure 11 For nickel sheets that have undergone surface mechanical polishing, the 5000 mA cm-coating test is performed after 3000 hours. -2 The graph shows a comparison of LSV curves before and after stability testing at current densities. Please refer to... Figure 11 The LSV curves before and after the stability test basically overlapped, indicating that the nickel sheet after surface mechanical polishing has excellent catalytic stability for the hydrogen evolution reaction under ultra-high current density.

[0071] This application also provides a surface modification device for improving the catalytic activity of metal materials. One embodiment of the surface modification device for improving the catalytic activity of metal materials includes a sample stage, a reflective chamber, a sphere, and a vibration generator. The sample stage is used to place the metal material and is disposed in the reflective chamber. The sphere is movably disposed in the reflective chamber. The vibration generator is used to generate oscillation waves to drive the sphere to move in the reflective chamber and impact the metal material on the sample stage.

[0072] In some embodiments, the sample stage may be located on top of the reflective chamber.

[0073] In some embodiments, the vibration generator may be an ultrasonic generator, which includes an ultrasonic power supply, an ultrasonic transducer, and an ultrasonic amplitude transformer connected to the ultrasonic transducer. The ultrasonic transducer converts the electrical signal generated by the ultrasonic power supply into an oscillating wave, and the ultrasonic amplitude transformer emits the oscillating wave, which drives the sphere to move within the reflecting cavity. It is understood that the vibration generator may also be other types of vibration generators, such as an electric vibrator.

[0074] In some embodiments, the metallic material may be nickel, iron, cobalt, copper, or titanium, or it may be a nickel alloy, iron alloy, cobalt alloy, copper alloy, or titanium alloy.

[0075] In some embodiments, the metallic material may be mesh metal, plate metal, or tubular metal.

[0076] In some embodiments, the metallic material is annealed or untreated before the surface mechanical grinding treatment is applied.

[0077] In some embodiments, the sphere may be a ceramic sphere or a metal sphere. Specifically, the metal sphere may be a nickel sphere, an iron sphere, a copper sphere, a titanium sphere, a nickel alloy sphere, an iron alloy sphere, a cobalt alloy sphere, a copper alloy sphere, or a titanium alloy sphere.

[0078] In some embodiments, the distance between the surface of the metal material and the ultrasonic amplitude transformer can be from 5 mm to 100 mm.

[0079] In some embodiments, the diameter of the sphere may be from 0.5 mm to 5 mm.

[0080] In some embodiments, the power of the ultrasonic power source may be from 1 kW to 10 kW.

[0081] This application also provides a metal catalytic material prepared by any of the above-mentioned surface modification methods for improving the catalytic activity of metal materials.

[0082] In some embodiments, the surface of the metal catalytic material comprises nanocrystals. Specifically, the grain size of the metal catalytic material gradually increases from the surface to the interior, creating a gradient structure composed of nanocrystals and non-nanocrystals (that is, the content of nanocrystals decreases while the content of non-nanocrystals increases from the surface to the interior of the metal catalytic material). The size of the nanocrystals is on the nanometer scale (e.g., greater than 1 nm and less than 1000 nm).

[0083] This application also provides the use of a metal catalytic material prepared by any of the above-mentioned surface modification methods for improving the catalytic activity of metal materials in hydrogen production through water electrolysis. Specifically, this metal catalytic material can be applied to alkaline electrolyzers or anion exchange membrane electrolyzers for hydrogen production through water electrolysis.

[0084] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A surface modification method for improving the catalytic activity of metallic materials, characterized in that, The surface modification method for improving the catalytic activity of metallic materials includes: Provide metal materials; The surface mechanical polishing treatment is applied to the surface of the metal material, wherein the surface mechanical polishing treatment includes: generating oscillation waves through a vibration generator to drive a ball to impact the metal material, thereby modifying the surface of the metal material to improve the catalytic activity of the metal material.

2. The surface modification method for improving the catalytic activity of metallic materials as described in claim 1, characterized in that, The metal material is any one of nickel, iron, cobalt, copper, titanium, nickel alloy, iron alloy, cobalt alloy, copper alloy, and titanium alloy.

3. The surface modification method for improving the catalytic activity of metallic materials as described in claim 1, characterized in that, The metal material is a mesh metal, a plate metal, or a tubular metal.

4. The surface modification method for improving the catalytic activity of metallic materials as described in claim 1, characterized in that, The sphere is a ceramic sphere or a metal sphere.

5. The surface modification method for improving the catalytic activity of metallic materials as described in claim 4, characterized in that, The metal spheres are made of nickel, iron, copper, titanium, nickel alloy, iron alloy, cobalt alloy, copper alloy, or titanium alloy.

6. The surface modification method for improving the catalytic activity of metallic materials as described in claim 1, characterized in that, The surface of the metal material undergoes deformation, microstructure changes, and residual stress after the surface mechanical grinding treatment.

7. The surface modification method for improving the catalytic activity of metallic materials as described in claim 6, characterized in that, The surface of the metal material after the surface mechanical polishing treatment includes nanocrystals. The grain size of the metal material gradually increases from the surface to the interior after the surface mechanical polishing treatment, and the metal material forms a gradient structure composed of nanocrystals and non-nanocrystals.

8. The surface modification method for improving the catalytic activity of metallic materials as described in claim 1, characterized in that, The vibration generator is an ultrasonic generator, which includes an ultrasonic power supply, an ultrasonic transducer, and an ultrasonic amplitude transformer connected to the ultrasonic transducer. In the step of driving the ball to impact the metal material through the vibration generator, the ultrasonic transducer converts the electrical signal generated by the ultrasonic power supply into an oscillation wave, the ultrasonic amplitude transformer emits the oscillation wave, and the oscillation wave emitted by the ultrasonic amplitude transformer drives the ball to move in the reflection chamber and impact the metal material located in the reflection chamber.

9. The surface modification method for improving the catalytic activity of metallic materials as described in claim 8, characterized in that, The ultrasonic power supply has a power of 1 kilowatt to 10 kilowatts.

10. The surface modification method for improving the catalytic activity of metallic materials as described in claim 8, characterized in that, The distance between the surface of the metal material and the ultrasonic amplitude transformer is 5 mm to 100 mm.

11. The surface modification method for improving the catalytic activity of metallic materials as described in claim 8, characterized in that, The diameter of the sphere is 0.5 mm to 5 mm.

12. The surface modification method for improving the catalytic activity of metallic materials as described in claim 1, characterized in that, The metal material is either annealed or untreated.

13. A surface modification device for improving the catalytic activity of metallic materials, characterized in that, The device includes a sample stage, a reflective chamber, a sphere, and a vibration generator. The sample stage is used to place a metal material and is disposed within the reflective chamber. The sphere is movably disposed within the reflective chamber. The vibration generator is used to generate oscillation waves to drive the sphere to move within the reflective chamber and impact the metal material on the sample stage.

14. The surface modification device for improving the catalytic activity of metallic materials as described in claim 13, characterized in that, The metal material is any one of nickel, iron, cobalt, copper, titanium, nickel alloy, iron alloy, cobalt alloy, copper alloy, and titanium alloy; the metal material is a mesh metal, a plate metal, or a tubular metal; the sphere is a ceramic sphere or a metal sphere.

15. The surface modification device for improving the catalytic activity of metallic materials as described in claim 13, characterized in that, The vibration generator is specifically an ultrasonic generator, which includes an ultrasonic power supply, an ultrasonic transducer, and an ultrasonic amplitude transformer connected to the ultrasonic transducer. The ultrasonic transducer is used to convert the electrical signal generated by the ultrasonic power supply into an oscillation wave, and the ultrasonic amplitude transformer is used to emit the oscillation wave. The oscillation wave emitted by the ultrasonic amplitude transformer is used to drive the sphere to move in the reflection chamber.

16. The surface modification device for improving the catalytic activity of metallic materials as described in claim 15, characterized in that, The distance between the surface of the metal material and the ultrasonic amplitude transformer is 5 mm to 100 mm; the diameter of the sphere is 0.5 mm to 5 mm; and the power of the ultrasonic power supply is 1 kW to 10 kW.

17. A metal catalytic material prepared by the surface modification method for improving the catalytic activity of metal materials according to any one of claims 1-12.

18. The metal catalytic material as described in claim 17, characterized in that, The surface of the metal catalytic material comprises nanocrystals.

19. The metal catalytic material as described in claim 18, characterized in that, The metal catalytic material has a gradually increasing grain size from the surface to the interior, and the metal catalytic material forms a gradient structure composed of nanocrystals and non-nanocrystals.

20. The use of a metal catalytic material prepared by a surface modification method for improving the catalytic activity of a metal material according to any one of claims 1-12 in the electrolysis of water to produce hydrogen.

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