Metallic component suitable for hydrogen production by electrolysis of water and method of preparation

Abstract

The application relates to a metal component suitable for hydrogen production by electrolysis of water and a preparation method, and belongs to the technical field of metal material combination. The preparation method comprises the following steps: preliminarily controlling the size of noble metal particles and the distribution of the noble metal particles on the sample surface in a subsequent deposition process by adjusting condition parameters of an acid pickling process; the condition parameters comprise that the acid pickling temperature ranges from 25 DEG C to 90 DEG C, and the acid pickling time ranges from 5 min to 2 h; finally controlling the size of the noble metal particles and the distribution of the noble metal particles on the sample surface by adopting electro-deposition or physical vapor deposition, so that the noble metal particles are uniformly distributed on the sample surface, and the size of the noble metal particle diameter ranges from 10 nm to 180 nm. The preparation method can realize low noble metal loading, can control the size of the noble metal particle diameter to range from 10 nm to 180 nm, and the noble metal loading of the prepared metal component sample ranges from 0.3 mg / cm 2 In the following, the average single-side coating thickness is below 70 nm, and the processing cost is effectively reduced.

Description

Technical Field

[0001] This application relates to the field of metal material bonding technology, specifically a metal component suitable for hydrogen production by water electrolysis and its preparation method. Background Technology

[0002] Industrial-grade pure titanium (TA1) is highly favored as the core material for bipolar plates and porous transport layers in PEM (proton exchange membrane) water electrolysis for hydrogen production due to its excellent thermal and electrical conductivity, superior durability, and chemical stability. However, in the actual operating environment of PEM water electrolysis for hydrogen production, titanium components face severe corrosion challenges from high potential, oxygen-rich environments, high temperatures, and acidic media. These conditions easily induce oxidation reactions, which not only increase contact resistance but also significantly affect the durability of the bipolar plates and reduce hydrogen production efficiency. Therefore, there is an urgent need to construct a highly conductive, highly corrosion-resistant, and long-durable coating system on the surface of titanium-based bipolar plates and porous transport layers.

[0003] Currently, various coating systems have been developed to address this need, mainly including:

[0004] Precious metal coatings, such as platinum, iridium, and gold, offer excellent performance, but their high content drives up costs, severely hindering the commercialization of water electrolysis technology.

[0005] Metal and non-metal doped coatings: Metals (such as TiN, ZrC, TiCN, TiNO) are modified by introducing one or more elements such as N, C, and O. However, in long-term use, oxygen atoms can easily penetrate into the interior of the coating, aggravating oxidation, resulting in increased contact resistance and compromised durability.

[0006] Non-precious metal doped coatings: Composite metal coatings are directly constructed on the substrate. Although the cost is low, they are prone to forming passivation films under actual electrolytic hydrogen production conditions. Although this improves corrosion resistance, it also increases contact resistance due to the formation of the passivation film, resulting in increased energy consumption and decreased hydrogen production efficiency.

[0007] Hybrid carbon coating: Hybrid carbon coating directly applied to titanium materials has shown some potential in the field of fuel cells. However, in the high-potential PEM water electrolysis hydrogen production environment, the hybrid carbon coating undergoes irreversible oxidation at high potential, which restricts its long-term stability.

[0008] While existing coating systems each have their own characteristics, key issues such as high cost, insufficient durability, or easy oxidation failure still need to be overcome in order to promote the further development and application of PEM water electrolysis hydrogen production technology.

[0009] Currently, some related technological research aims to solve the above problems. For example, patent document CN117947370A discloses a highly conductive, corrosion-resistant porous titanium diffusion layer, its preparation method, and its application. It describes: In step S02, noble metal particles are deposited on the etched porous titanium diffusion layer, and the size of the deposited noble metal particles is controlled to obtain a porous titanium diffusion layer with noble metal deposition. In step S03, an in-situ oxide layer growth treatment is performed on the porous titanium diffusion layer with noble metal deposition to fix the noble metal particles, resulting in a porous titanium diffusion layer with oxide-fixed noble metal particles. Furthermore, in step S03, the growth thickness after coating can be further adjusted according to the loading. The porous titanium diffusion layer obtained by this method can reduce the contact resistance of the porous titanium diffusion layer, improve its conductivity by converting titanium oxide into a conductive material, and increase the corrosion resistance of porous titanium; at the same time, it reduces the noble metal loading in the porous titanium coating and increases the coating adhesion through in-situ growth of the encapsulation structure. However, the noble metal particles obtained by this method have a particle size of 260–350 nm and a loading of 0.3–1.4 mg / cm³. 2 However, it is not very effective in reducing the amount of precious metals loaded.

[0010] Clearly, reducing the precious metal loading on the surface of metal components is crucial. However, there is no reliable solution in the existing technology to effectively reduce the precious metal loading. Therefore, there is an urgent need to develop a new metal component and preparation method suitable for hydrogen production by water electrolysis, in order to effectively reduce the precious metal loading on the surface of the metal component. Summary of the Invention

[0011] This application aims to at least partially solve one of the technical problems in the related art. To this end, this application provides a metal component and preparation method suitable for hydrogen production by water electrolysis. The method uses an electrochemical acid washing step to initially control the size and distribution of noble metal particles on the sample surface, and then uses electrodeposition or physical vapor deposition to ultimately control the size and distribution of noble metal particles on the sample surface, effectively reducing the amount of noble metal loaded and reducing processing costs.

[0012] To achieve the above objectives, in a first aspect, this application provides a metal component suitable for hydrogen production via water electrolysis, the metal component having a noble metal coating, the noble metal loading of the coating being 0.3 mg / cm³ on both sides. 2 The average single-sided coating thickness is below 70nm; the noble metal particles on the noble metal coating are uniformly distributed and the particle size is between 10nm and 180nm, wherein the difference between the maximum and minimum particle size is less than 130nm, and the average spacing between the noble metal particles is 38 to 227nm. The average spacing is defined as the average distance between all noble metal particles and their nearest N noble metal particles, where 10≥N≥2.

[0013] Preferably, the metal component is a titanium bipolar plate or a porous transport layer.

[0014] Secondly, this application provides a method for preparing a metal component suitable for hydrogen production by water electrolysis, comprising the following steps:

[0015] The size and distribution of noble metal particles on the sample surface during subsequent deposition can be initially controlled by adjusting the conditions and parameters of the acid pickling process; the conditions and parameters include an acid pickling temperature range of 25 to 90°C and an acid pickling time of 5 min to 2 h.

[0016] The size and distribution of noble metal particles on the sample surface are ultimately controlled by electrodeposition or physical vapor deposition, thereby finally producing metal parts with noble metal coatings.

[0017] Among them, the control parameters for electrodeposition need to meet the requirement of a current density of 1 mA to 200 mA / cm². 2 The duty cycle is 0%–60%, and the deposition time is 5s–600s. The control parameters for physical vapor deposition need to meet the following requirements: etching power of 50–300W, etching time of 5–60min, sputtering power of 50–500W, heating temperature of 100–1000℃, and deposition time of 30–3600s.

[0018] Preferably, the step of initially controlling the size of noble metal particles and their distribution on the sample surface during subsequent deposition by adjusting the condition parameters of the acid washing process includes: applying a negative potential to the sample through electrochemical acid washing to induce hydrogen evolution and permeation on its surface. Surface hydrogen evolution can make the surface energy of the exposed areas of the sample more uniform, and the probability of depositing noble metal particles more uniform. Surface hydrogen permeation can reduce noble metal ions to their surface due to the release of hydrogen in the sample during the deposition process, thereby achieving the deposition of small-diameter noble metal particles.

[0019] Preferably, the condition parameters further include the use of one or more of the following pickling solutions: oxalic acid, hydrochloric acid, sulfuric acid, nitric acid, and hydrofluoric acid.

[0020] Preferably, before the step of initially controlling the size of the precious metal particles and their distribution on the sample surface during the subsequent deposition process by adjusting the condition parameters of the acid washing process, the method includes: pre-setting the pre-deposition position of the precious metal particles on the sample surface by physical means.

[0021] Preferably, the step of pre-setting the pre-deposition position of the noble metal particles on the sample surface by physical means includes: preparing submicropores corresponding to the pre-deposition position on an acid and alkali resistant tape or a high temperature resistant mask plate, and attaching them to the sample surface.

[0022] Preferably, the step of preparing submicropores corresponding to the pre-deposition positions on an acid- and alkali-resistant tape or a high-temperature resistant mask at temperatures above 100°C includes: drilling holes with diameters between 100 nm and 10 μm on an acid- and alkali-resistant PET, PTFE, PVC, or PI tape or a high-temperature resistant mask at temperatures above 100°C using ultrafast laser drilling technology, thereby forming a design pattern corresponding to the pre-deposition positions.

[0023] Preferably, the step of pre-setting the pre-deposition position of the noble metal particles on the sample surface by physical means includes: constructing micron-sized arc-shaped metal particles on the sample surface corresponding to the pre-deposition position.

[0024] Preferably, the step of constructing micron-sized arc-shaped metal particles on the sample surface corresponding to the pre-deposition position includes: constructing micron-sized metal particles with a particle size of 0.5μm to 25μm on the sample surface by flame spraying, arc spraying, plasma spraying or thermal spraying to form a design pattern corresponding to the pre-deposition position.

[0025] Preferably, the micron-sized arc-shaped metal particles can withstand the harsh conditions of water electrolysis for hydrogen production and maintain corrosion resistance, and the metal composition is selected from one or more corrosion-resistant elements selected from Ti, Zr, Nb, Ta, Mo and W.

[0026] Preferably, the steps for ultimately controlling the size and distribution of noble metal particles on the sample surface using electrodeposition or physical vapor deposition include: using electrodeposition, controlling the size and distribution of noble metal particles by adjusting the parameters of the pulse power supply, current magnitude, frequency, duty cycle, and deposition time; or using physical vapor deposition, controlling the size and distribution of noble metal particles by adjusting the power, target spacing, and deposition time.

[0027] Based on the above technical solution, the metal component and preparation method for hydrogen production by water electrolysis proposed in this application have the following advantages compared to the prior art:

[0028] This application describes a method for preparing metal components for hydrogen production via water electrolysis. This method employs an electrochemical acid washing step to initially control the size and distribution of noble metal particles on the sample surface. Then, electrodeposition or physical vapor deposition is used to ultimately control the size and distribution of the noble metal particles on the sample surface, ensuring a uniform distribution of the noble metal particles with a particle size between 10 nm and 180 nm. The resulting metal component sample has a noble metal loading of 0.3 mg / cm² on both sides. 2The average single-sided coating thickness is below 70nm, and the average spacing of the precious metal particles is 38-227nm, which effectively reduces the amount of precious metal and reduces processing costs.

[0029] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description, or may be realized by practice of this application. The purpose and other advantages of this application can be realized and obtained by means of the structures particularly pointed out in the written description, claims and drawings. Attached Figure Description

[0030] Figure 1 This is a flowchart of a first embodiment of a method for preparing a metal component suitable for hydrogen production by water electrolysis according to this application;

[0031] Figure 2 This is a SEM microstructure of a titanium substrate sample with a low platinum loading coating obtained by a method for preparing a metal component suitable for hydrogen production by water electrolysis according to this application.

[0032] Figure 3 This is a flowchart of a second embodiment of a method for preparing a metal component suitable for hydrogen production by water electrolysis according to this application;

[0033] Figure 4 This is a flowchart of a third embodiment of a method for preparing a metal component suitable for hydrogen production by water electrolysis according to this application;

[0034] Figure 5 This is a flowchart of a fourth embodiment of a method for preparing a metal component suitable for hydrogen production by water electrolysis according to this application;

[0035] Figure 6 This is a flowchart of a fifth embodiment of a method for preparing a metal component suitable for hydrogen production by water electrolysis according to this application. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0037] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of this invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0038] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing metal components suitable for hydrogen production by water electrolysis, in order to effectively reduce the noble metal loading on the surface of the metal components.

[0039] The basic idea of ​​this invention is to initially control the size and distribution of noble metal particles on the sample surface through an electrochemical acid washing step, and then to ultimately control the size and distribution of noble metal particles on the sample surface through electrodeposition or physical vapor deposition, so that the noble metal loading of the coating is 0.3 mg / cm² on both sides. 2 The following conditions apply: the average single-sided coating thickness is less than 70 nm; the noble metal particles are uniformly distributed with intervals on the sample surface; the particle size of the noble metal particles is between 10 nm and 180 nm; the difference between the maximum and minimum particle size of the noble metal particles is less than 130 nm; and the average spacing between the noble metal particles is 38 to 227 nm. The average spacing is defined as the average distance between each noble metal particle and its nearest N noble metal particles, where 10 ≥ N ≥ 2.

[0040] The method specifically includes:

[0041] The size of noble metal particles and their distribution on the sample surface during subsequent deposition can be initially controlled by adjusting the conditions and parameters of the electrochemical pickling process. The conditions and parameters include a pickling temperature range of 25 to 90°C and a pickling time of 5 min to 2 h. More preferably, the pickling temperature range can also be selected as 40 to 60°C and the pickling time can be selected as 20 min to 2 h.

[0042] The size and distribution of noble metal particles on the sample surface are ultimately controlled using electrodeposition or physical vapor deposition to ensure a uniform, spaced distribution of the particles with a particle size between 10 nm and 180 nm, thereby ultimately producing a metal component with a noble metal coating. The electrodeposition control parameters must meet a current density of 1 mA to 200 mA / cm². 2 The duty cycle is 0%–60%, and the deposition time is 5s–600s. The control parameters for physical vapor deposition need to meet the following requirements: etching power of 50–300W, etching time of 5–60min, sputtering power of 50–500W, heating temperature of 100–1000℃, and deposition time of 30–3600s.

[0043] The surface energy difference of the metal component samples after acid washing using a specific electrochemical method is very small, thus ensuring a uniformly distributed deposition effect. Furthermore, by controlling the conditions and parameters of the electrochemical acid washing process, hydrogen evolution and permeation can be induced on the sample surface. Surface hydrogen evolution makes the surface energy of exposed areas of the sample tend to be uniform, thus ensuring a consistent probability of noble metal particle deposition. Surface hydrogen permeation allows the release of hydrogen from the sample during deposition to reduce noble metal ions to their surface, thereby achieving the deposition of small-diameter noble metal particles. By adjusting the conditions and parameters of the electrochemical acid washing process within the aforementioned range, a uniformly distributed noble metal particle deposition effect on the sample surface can be achieved. Ultimately, by controlling the size of the noble metal particles and their uniform distribution on the sample surface, the noble metal loading of the prepared metal component sample is 0.3 mg / cm² on both sides. 2 The average single-sided coating thickness is below 70nm, which effectively reduces the amount of precious metals and lowers processing costs.

[0044] Example 1

[0045] This embodiment provides a metal component suitable for hydrogen production via water electrolysis. The metal component has a noble metal coating, and the noble metal loading of the coating is 0.3 mg / cm² on both sides. 2 The average single-sided coating thickness is below 70 nm; the noble metal particles on the noble metal coating are uniformly distributed, and the particle size is between 10 nm and 180 nm, wherein the difference between the maximum and minimum particle size is less than 130 nm, and the average spacing between the noble metal particles is 38–227 nm. The average spacing is defined as the average distance between each noble metal particle and its N nearest neighbors, where 10 ≥ N ≥ 2. Specifically, the metal component can be a titanium bipolar plate or a porous transport layer.

[0046] Further preferably, when the size of the noble metal particles is between 10 nm and 80 nm, the difference between the maximum and minimum particle sizes is less than 15 nm, and the average spacing between the noble metal particles is 38–60 nm. At this point, because the size difference between the noble metal particles is smaller, the particle size is more uniform, and the overall distribution distance is also more uniform. Therefore, the noble metal loading of the coating at 0.3 mg / cm² on both sides can still be achieved. 2 The following describes the technical effects of an average single-sided coating thickness of less than 70nm.

[0047] Example 2

[0048] In order to develop a method to effectively reduce the noble metal loading on the surface of metal component samples, the inventors conducted in-depth research on the control of electrochemical acid washing and deposition processes, and proposed a method for preparing metal components suitable for hydrogen production by water electrolysis.

[0049] Specifically, such as Figure 1 As shown, a method for preparing a metal component suitable for hydrogen production by water electrolysis includes the following steps:

[0050] S1. Select titanium felt of a fixed size as a sample, and pickle the sample with oxalic acid at a concentration of 5% to 20% at a temperature of 25 to 90°C for 5 min to 2 h.

[0051] S2. After acid washing, rinse the sample repeatedly with deionized water, wipe it dry and set it aside for later use.

[0052] S3. The acid-washed sample and a platinum sheet of a fixed size are placed in an electroplating solution with a temperature range of 25–70°C for electrodeposition. The size and distribution of the noble metal particles are controlled by adjusting the parameters of the pulse power supply, including current magnitude, frequency, duty cycle, and deposition time. The metal component can be a titanium bipolar plate or a porous transport layer.

[0053] Preferably, the control parameters for electrodeposition need to meet the requirement of a current density of 5 mA to 200 mA / cm². 2 The duty cycle is 15% to 60%, and the deposition time is 60 to 600 seconds.

[0054] Specifically, in this embodiment, step S1 uses a 5cm×5cm titanium felt as the sample. The sample is statically acid-washed with 10% oxalic acid at a temperature of 80℃ for 1 hour. The oxide film on the surface of the bipolar plate and the porous transport layer is removed by adjusting the acid washing parameters. (The porous transport layer has a porous structure; adjusting the parameters and methods ensures thorough acid washing of the exposed surface area, facilitating the adhesion of noble metal particles within the exposed area.) In step S3, the acid-washed sample and a 5cm×5cm platinum sheet are placed in an electroplating solution preheated to 35℃. The sample is connected to the negative electrode of a pulse power supply, and the positive electrode is connected to the platinum sheet. The size and distribution of the noble metal particles are controlled by adjusting the pulse power supply parameters, current magnitude, frequency, duty cycle, and deposition time. In this embodiment, the pulse power supply parameters are specifically set as follows: current magnitude 5mA, duty cycle 15%, frequency 50Hz, and deposition time 200s. The resulting SEM microstructure of the low platinum loading coating on the titanium substrate sample is shown below. Figure 2 As shown in (a), the noble metal loading of the noble metal coating formed by the method of this embodiment is 0.3 mg / cm² on both sides. 2In the following examples, the average single-sided coating thickness is less than 50 nm, and the size of the formed precious metal particles is between 50 nm and 180 nm. The difference between the maximum and minimum particle sizes is less than 130 nm. The average spacing between the precious metal particles is 38–227 nm, defined as the average distance between each precious metal particle and its eight nearest neighbors. It should be noted that, in addition to the static pickling method used in this embodiment, pickling can also be achieved using ultrasonic pickling, agitation pickling, electrochemical pickling, etc.

[0055] Furthermore, preferably, while ensuring that all other parameters remain the same as in Example 1, the SEM microstructure of the low platinum loading coating of the titanium substrate sample obtained by changing the static pickling method to an electrochemical pickling method is shown in the figure below. Figure 2 As shown in (b), the noble metal loading of the noble metal coating formed by this method is also 0.3 mg / cm² on both sides. 2 The average single-sided coating thickness is also below 70 nm. However, the particle size of the noble metal particles is between 10 nm and 80 nm, and the difference between the maximum and minimum particle sizes is less than 15 nm, resulting in more uniform particle size and better performance than static acid washing. This is because electrochemical acid washing applies a negative potential to the sample, causing hydrogen evolution and permeation on its surface. Surface hydrogen evolution makes the surface energy of the exposed areas of the sample more uniform, leading to a more consistent probability of noble metal particle deposition, thus minimizing the difference in particle size. Furthermore, under electrochemical acid washing conditions, the average spacing between the noble metal particles is 38–60 nm, defined as the average distance between each noble metal particle and its eight nearest neighbors.

[0056] Furthermore, preferably, when the electroplating current in Example 1 is 0A (i.e., no current is applied), the deposition time is 2 hours, and the static pickling method is changed to an electrochemical pickling method, the SEM microstructure of the low platinum loading coating of the titanium substrate sample is shown in the figure. Figure 2 As shown in (c), the noble metal loading of the noble metal coating formed by this method is also 0.3 mg / cm² on both sides. 2 The average single-sided coating thickness is also below 70nm, and the effect is better than that of static pickling.

[0057] Titanium felt is a porous titanium material with high porosity and good electrical conductivity. It can be used as a porous transport layer or as part of a bipolar plate to improve the efficiency and durability of water electrolysis hydrogen production equipment. When depositing noble metal particles on the surface of titanium felt, we expect the particles to be deposited uniformly. Therefore, in this embodiment, a negative potential is applied to the sample through electrochemical acid washing, causing hydrogen evolution and permeation on its surface. Surface hydrogen evolution makes the surface energy of the exposed areas of the sample more uniform, thus making the probability of noble metal particle deposition more uniform. Surface hydrogen permeation allows the release of hydrogen from the sample during deposition to reduce noble metal ions to their surface, thereby achieving the deposition of small-diameter noble metal particles. By adjusting the conditions and parameters of the electrochemical acid washing process within the above-mentioned range, a uniformly distributed distribution of noble metal particles on the sample surface can be achieved.

[0058] The present invention relates to a method for preparing a titanium bipolar plate and porous transport layer for hydrogen production via water electrolysis, which effectively reduces the precious metal loading (most commercially available plates have a loading of ≥0.8 mg / cm³) for the water electrolysis hydrogen production industry. 2 No, the titanium bipolar plate and porous transport layer coating for hydrogen production by water electrolysis involved in this invention have high conductivity, corrosion resistance and durability while having a low noble metal loading.

[0059] Example 3

[0060] like Figure 3 The diagram shown is a flowchart of a second embodiment of a method for preparing a metal component suitable for hydrogen production by water electrolysis according to this application. In this embodiment, the preparation method includes:

[0061] S1. Holes with diameters between 100nm and 10μm are drilled on PET tape that is resistant to acids and alkalis and temperatures above 100℃ using ultrafast laser drilling technology, and the PET tape is then glued to the surface of the titanium felt sample on both sides.

[0062] S2. The sample is acid-washed with oxalic acid at a concentration of 5% to 20%, at a temperature of 25 to 90°C, for a time of 5 min to 2 h.

[0063] S3. After acid washing, rinse the sample repeatedly with deionized water, wipe it dry and set it aside for later use.

[0064] S4. The acid-washed sample and a platinum sheet of a fixed size are placed in an electroplating solution with a temperature range of 25 to 70°C for electrodeposition. The size and distribution of the precious metal particles are controlled by adjusting the parameters of the pulse power supply, including current magnitude, frequency, duty cycle and deposition time.

[0065] S5. Remove the tape adhering to the surface of the titanium felt sample.

[0066] Preferably, the control parameters for electrodeposition need to meet the requirement of a current density of 25 mA to 200 mA / cm². 2 The duty cycle is 25%–60%, and the deposition time is 30s–600s.

[0067] Specifically, in this embodiment, in step S1, 1μm holes are drilled in the acid- and alkali-resistant PET tape, which is resistant to temperatures above 100°C, using ultrafast laser drilling technology. The distribution of the holes can be designed independently. In step S2, acid washing is performed using 10% sulfuric acid, with heating treatment during the washing process at 60°C for 1.2 hours. The washing methods can include static washing, ultrasonic washing, agitated washing, and electrochemical washing. By adjusting the above washing conditions, the oxide film on the surface of the bipolar plate and the porous transport layer is removed (the porous transport layer has a porous structure; adjusting the parameters and methods ensures thorough acid washing of the exposed areas, facilitating the adhesion of precious metal particles within these areas). In step S3, the acid-washed titanium substrate sample is rinsed with deionized water at least three times. In step S4, the acid-washed sample and a 5cm × 5cm platinum sheet are placed in an electroplating solution preheated to 40°C. The sample is connected to the negative terminal of a pulse power supply, and the positive terminal is connected to the platinum sheet. In this embodiment, the size and distribution of noble metal particles are controlled by adjusting the parameters of the pulse power supply, including current magnitude, frequency, duty cycle, and deposition time. Specifically, the pulse power supply parameters are set as follows: current magnitude 100mA, duty cycle 25%, frequency 50Hz, and deposition time 140s. The noble metal loading of the resulting coating is 0.3 mg / cm² on both sides. 2 The average single-sided coating thickness is below 40nm, and the size of the formed noble metal particles is between 50nm and 180nm.

[0068] In this embodiment, a negative potential is applied to the sample via electrochemical acid washing, causing hydrogen evolution on its surface. By adjusting the conditions and parameters of the electrochemical acid washing process within the aforementioned range, the surface energy difference of the metal component sample after acid washing is minimized, resulting in a uniformly distributed, spaced deposition pattern on the sample surface. Specifically, in this embodiment, applying a negative potential to the sample via electrochemical acid washing causes hydrogen evolution and diffusion on its surface. Surface hydrogen evolution makes the surface energy of the exposed areas of the sample more uniform, thus making the probability of depositing noble metal particles more consistent. Surface hydrogen diffusion allows the release of hydrogen from the sample during the deposition process to reduce noble metal ions to their surface, thereby achieving the deposition of small-diameter noble metal particles.

[0069] This electrolytic hydrogen production titanium bipolar plate and porous transport layer coating scheme effectively reduces the precious metal loading while simultaneously possessing high conductivity, corrosion resistance, and durability, ensuring its long service life under operating conditions.

[0070] Example 4

[0071] like Figure 4 The diagram shown is a flowchart of a third embodiment of a method for preparing a metal component suitable for hydrogen production by water electrolysis according to this application. In this embodiment, the preparation method includes:

[0072] S1. Holes with diameters between 100nm and 10μm are drilled on PET tape that is resistant to acids and alkalis and temperatures above 100℃ using ultrafast laser drilling technology, and the PET tape is then glued to the surface of the titanium felt sample on both sides.

[0073] S2. The sample is acid-washed with oxalic acid at a concentration of 5% to 20%, at a temperature of 25 to 90°C, for a time of 5 min to 2 h.

[0074] S3. After acid washing, rinse the sample repeatedly with deionized water, wipe it dry and set it aside for later use.

[0075] S4. Perform physical vapor deposition on the acid-washed sample, and control the size and distribution of noble metal particles by adjusting the power, target spacing and deposition time.

[0076] S5. Remove the tape adhering to the surface of the titanium felt sample.

[0077] Preferably, the control parameters for physical vapor deposition should meet the following requirements: etching power of 100–300 W, etching time of 10–60 min, sputtering power of 100–500 W, heating temperature of 200–1000 °C, and deposition time of 1000–3600 s.

[0078] Specifically, in this embodiment, in step S1, 150nm holes are drilled on an acid- and alkali-resistant PET tape that can withstand temperatures above 100°C using ultrafast laser drilling technology. The distribution of the holes can be designed independently. In step S2, acid washing is performed using 10% nitric acid, with heating treatment during the washing process at 90°C for 50 minutes. The acid washing method can include static acid washing, ultrasonic acid washing, agitated acid washing, electrochemical acid washing, etc. By adjusting the above acid washing conditions, the oxide film on the surface of the bipolar plate and the porous transport layer is removed (the porous transport layer has a porous structure; adjusting the parameters and methods ensures that the exposed areas of its surface are thoroughly acid-washed, facilitating the adhesion of noble metal particles within the exposed areas). In step S3, the acid-washed titanium substrate sample is rinsed with deionized water at least three times. In step S4, physical vapor deposition is performed on the acid-washed sample. The size and distribution of noble metal particles are controlled by adjusting the power, target spacing, and deposition time. Specifically, the platinum target and the sample are connected to the negative terminal of a DC power supply or grounded, and the DC power supply provides the electric field required for sputtering. In this embodiment, the magnetron sputtering DC sputtering power is 500W, the target spacing is 8cm, and the sputtering time is 30min. The noble metal loading of the formed noble metal coating is 0.3mg / cm² on both sides. 2The average single-sided coating thickness is below 30nm, and the size of the formed noble metal particles is between 10nm and 40nm.

[0079] Example 5

[0080] like Figure 5 The diagram shown is a flowchart of a fourth embodiment of a method for preparing a metal component suitable for hydrogen production by water electrolysis according to this application. In this embodiment, the preparation method includes:

[0081] S1. Micron-sized metal particles with a particle size of 0.5μm to 25μm are constructed on the sample surface by thermal spraying;

[0082] S2. The sample is acid-washed with oxalic acid at a concentration of 5% to 20%, at a temperature of 40 to 60°C, for a time of 20 min to 2 h.

[0083] S3. After acid washing, rinse the sample repeatedly with deionized water, wipe it dry and set it aside for later use.

[0084] S4. The acid-washed sample and a platinum sheet of a fixed size are placed in an electroplating solution with a temperature range of 25-70℃ for electrodeposition. The size and distribution of the precious metal particles are controlled by adjusting the parameters of the pulse power supply, including current magnitude, frequency, duty cycle and deposition time.

[0085] Specifically, in this embodiment, in step S1, micron-sized arc-shaped metal particles with a particle size of 0.8 μm are constructed on the sample surface by thermal spraying. It should be noted that constructing micron-sized arc-shaped metal particles on the sample surface corresponding to the pre-deposition position is only one preferred method of this application. Other shapes of micron-sized metal particles corresponding to the pre-deposition position can also be constructed on the sample surface, as long as they can form protrusions relative to the sample surface. In step S2, 15% hydrochloric acid is used for pickling, with heating treatment performed at 50°C for 50 minutes. Pickling methods can include static pickling, ultrasonic pickling, stirring pickling, electrochemical pickling, etc. By adjusting the above pickling conditions, the oxide film on the surface of the bipolar plate and the porous transport layer is removed (the porous transport layer has a porous structure; adjusting the parameters and methods ensures sufficient pickling of the exposed surface area, facilitating the adhesion of noble metal particles in the exposed area). In step S3, the pickled titanium substrate sample is rinsed with deionized water at least three times. In step S4, the acid-washed sample and a 5cm × 5cm platinum sheet are placed in an electroplating solution preheated to 45°C. The sample is connected to the negative terminal of a pulse power supply, and the positive terminal is connected to the platinum sheet. The size and distribution of the noble metal particles are controlled by adjusting the pulse power supply parameters: current magnitude, frequency, duty cycle, and deposition time. In this embodiment, the pulse power supply parameters are specifically set as follows: current magnitude 1.4A, duty cycle 25%, frequency 50Hz, and deposition time 160s. The noble metal loading of the resulting coating is 0.3 mg / cm² on both sides. 2 The average single-sided coating thickness is below 60nm, and the size of the formed noble metal particles is between 50nm and 180nm.

[0086] Non-precious metal doped coatings are prone to passivation under operating conditions. While they exhibit good corrosion resistance, the formation of the passivation film leads to increased contact resistance and poor durability. This embodiment, however, deposits a layer of noble metal on micron-sized metal particles composed of corrosion-resistant elements such as Ti, Zr, Nb, Ta, Mo, and W, ensuring a noble metal loading of 0.3 mg / cm² on both sides. 2The following further explains why precious metal particles preferentially deposit at the locations corresponding to micron-sized metal particles: Micron-sized metal particles form protrusions relative to the sample surface. On one hand, during acid pickling and corrosion, the protruding parts of the metal material often act as anodes (i.e., electron donors), while the recessed or relatively flat parts may act as cathodes (i.e., electron acceptors). In an acidic environment, the anode dissolves more quickly (due to the relatively large contact area between the protruding part and the electrolyte, and the higher current density, thus accelerating the corrosion reaction), while the cathode is protected. This results in the protruding parts being preferentially corroded, the oxide film at the protrusions being dissolved, and the surface becoming metallic, making it easier for precious metal particles to deposit. On the other hand, due to their shape characteristics, protruding parts usually have higher surface energy. High surface energy means that surface atoms or molecules are more active and more likely to react with other substances. Therefore, in an acidic environment, protruding parts are more likely to dissolve due to their higher surface energy. Furthermore, the protruding parts often exhibit stress concentration in their structure. This stress concentration can lead to changes in the microstructure of the material in that region, such as lattice distortion and an increase in dislocations. Consequently, the protruding parts with stress concentration are more prone to dissolution in acidic environments, and the surface of the corresponding protruding location becomes metallic, making it easier for noble metal particles to deposit. The metal component surface treated in this embodiment has a low noble metal loading while simultaneously exhibiting high conductivity, corrosion resistance, and durability, ensuring its long service life under operating conditions.

[0087] Example 6

[0088] like Figure 6 The diagram shown is a flowchart of a fifth embodiment of a method for preparing a metal component suitable for hydrogen production by water electrolysis according to this application. In this embodiment, the preparation method includes:

[0089] S1. Micron-sized metal particles with a particle size of 0.5μm to 25μm are constructed on the sample surface by arc spraying.

[0090] S2. The sample is acid-washed with oxalic acid at a concentration of 5% to 20%, at a temperature of 25 to 90°C, for a time of 5 min to 2 h.

[0091] S3. After acid washing, rinse the sample repeatedly with deionized water, wipe it dry and set it aside for later use.

[0092] S4. Perform physical vapor deposition on the acid-washed sample, and control the size and distribution of the noble metal particles by adjusting the power, target spacing and deposition time.

[0093] Specifically, in this embodiment, in step S1, micron-sized metal particles with a particle size of 10 μm are constructed on the sample surface by arc spraying, preferably micron-sized arc-shaped metal particles. It should be noted that constructing micron-sized arc-shaped metal particles on the sample surface corresponding to the pre-deposition position is only one preferred method of this application. Other shapes of micron-sized metal particles corresponding to the pre-deposition position can also be constructed on the sample surface, as long as they can form protrusions relative to the sample surface. In step S2, 12% hydrochloric acid is used for pickling, with heating treatment performed at 85°C for 35 minutes. Pickling methods can include static pickling, ultrasonic pickling, stirring pickling, electrochemical pickling, etc. By adjusting the above pickling conditions, the oxide film on the surface of the bipolar plate and the porous transport layer is removed (the porous transport layer has a porous structure; adjusting the parameters and methods ensures sufficient pickling of the exposed surface area, facilitating the adhesion of noble metal particles in the exposed area). In step S3, the pickled titanium substrate sample is rinsed with deionized water at least three times. In step S4, physical vapor deposition is performed on the acid-washed sample. The size and distribution of noble metal particles are controlled by adjusting the power, target spacing, and deposition time. Specifically, the platinum target and sample are connected to the negative terminal of a DC power supply or grounded. The DC power supply provides the electric field required for sputtering. In this embodiment, the magnetron sputtering DC sputtering power is 500W, the target spacing is 8cm, and the sputtering time is 20min. The noble metal loading of the formed noble metal coating is 0.3mg / cm² on both sides. 2 The average single-sided coating thickness is below 70nm, and the size of the formed noble metal particles is between 10nm and 40nm.

[0094] This embodiment uses physical vapor deposition to control the size and distribution of noble metal particles by adjusting the power, target spacing, and deposition time, so that the noble metal loading of the final sample surface coating is 0.3 mg / cm² on both sides. 2 The following is a further explanation. Furthermore, while non-precious metal doped coatings are prone to passivation under operating conditions and exhibit good corrosion resistance, their durability suffers due to increased contact resistance caused by the formation of the passivation film. In this embodiment, although a layer of noble metal is deposited on micron-sized metal particles composed of corrosion-resistant elements such as Ti, Zr, Nb, Ta, Mo, and W, the noble metal loading at 0.3 mg / cm² on both sides is not guaranteed. 2 The metal parts processed according to this embodiment have high electrical conductivity, corrosion resistance and durability while having a low noble metal load, thus ensuring their long service life under working conditions.

[0095] The foregoing has described specific embodiments of the present invention. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps described in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0096] In the description of the embodiments of the present invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In the embodiments of the present invention, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in the embodiments of the present invention, as well as the features of the different embodiments or examples.

[0097] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features, excluding any ordering. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature and is used to distinguish it from another. In the description of embodiments of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0098] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing custom logic functions or processes, and the scope of preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of the invention pertain.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A metal component suitable for hydrogen production via water electrolysis, characterized in that, The metal component has a noble metal coating, and the noble metal loading of the coating is 0.3 mg / cm² on both sides. 2 The average single-sided coating thickness is below 70nm; the noble metal particles on the noble metal coating are uniformly distributed and the particle size is between 10nm and 180nm, wherein the difference between the maximum and minimum particle size is less than 130nm, and the average spacing between the noble metal particles is 38 to 227nm. The average spacing is defined as the average of the distances between all noble metal particles and their nearest N noble metal particles, where 10≥N≥2. The method for preparing the metal component includes the following steps: The size and distribution of precious metal particles on the sample surface can be initially controlled by adjusting the conditions and parameters of the acid pickling process. The size and distribution of noble metal particles on the sample surface are ultimately controlled by electrodeposition or physical vapor deposition, thereby obtaining metal parts with noble metal coatings.

2. The metal component according to claim 1, characterized in that, The metal component is a titanium bipolar plate or a porous transport layer.

3. A method for preparing a metal component suitable for hydrogen production by water electrolysis, used to prepare a noble metal coating on the metal component as described in claim 1 or 2, characterized in that, The specified parameters include an acid pickling temperature range of 25–90°C and an acid pickling time of 5 min–2 h; the electrodeposition control parameters must meet a current density of 1 mA–200 mA / cm². 2 The duty cycle is 0%–60%, and the deposition time is 5s–600s. The control parameters for physical vapor deposition need to meet the following requirements: etching power of 50–300W, etching time of 5–60min, sputtering power of 50–500W, heating temperature of 100–1000℃, and deposition time of 30–3600s.

4. The preparation method according to claim 3, characterized in that, The steps to initially control the size and distribution of noble metal particles on the sample surface during subsequent deposition by adjusting the conditions and parameters of the acid washing process include: applying a negative potential to the sample through electrochemical acid washing to induce hydrogen evolution and permeation on the surface. Surface hydrogen evolution can make the surface energy of the exposed areas of the sample more uniform, and the probability of depositing noble metal particles more uniform. Surface hydrogen permeation can reduce noble metal ions to their surface due to the release of hydrogen in the sample during the deposition process, thereby achieving the deposition of small-diameter noble metal particles.

5. The preparation method according to claim 3, characterized in that, The conditions and parameters also include the selection of one or more of the following pickling solutions: oxalic acid, hydrochloric acid, sulfuric acid, nitric acid, and hydrofluoric acid.

6. The preparation method according to claim 3, characterized in that, Before the step of initially controlling the size and distribution of precious metal particles on the sample surface during subsequent deposition by adjusting the condition parameters of the acid washing process, the method includes: pre-setting the pre-deposition position of the precious metal particles on the sample surface by physical means.

7. The preparation method according to claim 6, characterized in that, The step of pre-setting the pre-deposition position of noble metal particles on the sample surface by physical means includes: preparing submicropores corresponding to the pre-deposition position on an acid and alkali resistant tape or a high temperature resistant mask plate, and attaching them to the sample surface.

8. The preparation method according to claim 7, characterized in that, The step of preparing submicropores corresponding to the pre-deposition positions on acid and alkali resistant tape or high-temperature resistant photomask includes: drilling holes with diameters between 100 nm and 10 μm on acid and alkali resistant PET, PTFE, PVC or PI tape or high-temperature resistant photomask using ultrafast laser drilling technology to form a design pattern corresponding to the pre-deposition positions.

9. The preparation method according to claim 6, characterized in that, The step of pre-setting the pre-deposition position of noble metal particles on the sample surface by physical means includes: constructing micron-sized arc-shaped metal particles on the sample surface corresponding to the pre-deposition position.

10. The preparation method according to claim 9, characterized in that, The steps of constructing micron-sized arc-shaped metal particles on the sample surface corresponding to the pre-deposition position include: constructing micron-sized metal particles with a particle size of 0.5μm to 25μm on the sample surface by flame spraying, arc spraying, plasma spraying or thermal spraying to form a design pattern corresponding to the pre-deposition position.

11. The preparation method according to claim 10, characterized in that, The micron-sized arc-shaped metal particles can withstand the harsh conditions of water electrolysis for hydrogen production and maintain corrosion resistance. The metal composition is selected from one or more corrosion-resistant elements among Ti, Zr, Nb, Ta, Mo and W.

12. The preparation method according to claim 11, characterized in that, The steps for ultimately controlling the size and distribution of noble metal particles on the sample surface using electrodeposition or physical vapor deposition include: using electrodeposition, controlling the size and distribution of noble metal particles by adjusting the parameters of the pulse power supply, current magnitude, frequency, duty cycle, and deposition time; or using physical vapor deposition, controlling the size and distribution of noble metal particles by adjusting the power, target spacing, and deposition time.

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