Method for testing binding force and uniformity of alkaline electrolytic water hydrogen production electrode catalyst

Abstract

The invention provides a method for testing binding force and uniformity of an alkaline electrolytic water hydrogen production electrode catalyst, which comprises two processes of experimental equipment construction and experimental operation, and the experimental equipment construction comprises the steps of preparing a test solution A, preparing a test solution B, preparing an anti-corrosion support plate, preparing a sample and assembling the test equipment; and switching on a power supply for testing and recording data. Compared with a traditional testing method, the testing method capable of simulating electrode failure is shorter in testing time, more flexible and particularly capable of reflecting the strength of the bonding capacity of the catalyst and the electrode base material more visually and conveniently. Compared with a general test method, the method has the characteristics of more flexibility, rapidness, convenience, lower time and labor cost and the like.

Description

Technical Field

[0001] This invention relates to a method for testing the bonding force and uniformity of electrode catalysts in alkaline water electrolysis hydrogen production, and relates to the field of electrode testing in hydrogen production equipment. Background Technology

[0002] The binding force and uniformity of electrode catalysts in alkaline water electrolysis for hydrogen production are key parameters affecting electrode performance; therefore, evaluating their binding force and uniformity is particularly important. Existing methods for testing binding force and uniformity are susceptible to numerous interfering factors, especially when using a three-electrode system. The reference electrode exhibits poor stability under high alkalinity and high temperature environments. Furthermore, ultrasonic testing in an alkaline environment fails to provide a direct visual observation of electrode detachment even when exhibiting good binding force. Additionally, the electrode binding force cannot be accurately determined, making it impossible to compare electrodes of higher quality under this standard. Finally, the electrode catalytic failure curve cannot be observed.

[0003] Currently, there is no relevant testing method in this field that can strip the catalyst from the nickel mesh substrate in a short time, and the limited testing time cannot accurately indicate whether the electrode has failed. The industry-accepted method is to test the entire electrolytic cell for one month. If the electrode performance is stable, the electrode life is considered to be qualified, or the problem can be reflected by the overpotential change trend mentioned in the national standard.

[0004] In view of this, it is necessary to improve the existing testing methods to solve the above problems. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: in order to overcome the shortcomings of the prior art, the present invention provides a test method for the binding force and uniformity of the electrode catalyst for alkaline water electrolysis to produce hydrogen.

[0006] Test Principle Explanation: The test method of this invention is a single acid etching method. First, nickel metal does not corrode in an alkaline environment from a corrosion principle perspective. That is, the Raney nickel mesh, composed of the catalyst and the nickel mesh substrate, will theoretically never chemically dissolve inside the electrolytic cell. Therefore, if the performance of the electrolytic cell deteriorates or fails and it is determined to be due to the electrodes, the Raney nickel mesh can only be due to catalyst detachment. Moreover, this detachment is caused by physical action, such as electrolyte scouring, hydrogen bubble leakage to the junction, or hydrogen embrittlement. Electrode failure due to other special reasons will not be discussed in detail here, such as the toxic effects of impurities in the electrolyte. The life test comparison method in this patent only simulates physical impact under normal conditions, nickel corrosion under extreme conditions (high temperature, high voltage, high alkali), and abnormal nickel corrosion. Based on the core mechanism of electrochemical corrosion, namely electron transfer, simplified to the smallest single nickel atom, under certain external conditions, this nickel atom causes two or more of its electrons to transfer. At the same time, without other anions such as oxygen to form a stable molecular state with it, the nickel atom will change from an element to an ionic state, thus entering the solution and being lost. The nickel mesh or catalyst will corrode, accelerating this process, resulting in the shedding and dissolution of a large amount of catalyst, and electrode failure. Often, this external condition for chemical corrosion, that is, the external force that causes the nickel atom to lose electrons, does not exist in an alkaline environment, or in other words, this force will not be observed on a short time scale. Perhaps it will be observed when the time scale is large enough, such as 10 years or 20 years. However, in scientific experiments, this process needs to be accelerated. This involves utilizing the fact that nickel metal cannot exist in acidic environments to corrode the nickel at the point where the catalyst and electrode are bonded. Simultaneously, the catalyst itself corrodes, as does the nickel wire mesh substrate of the electrode. The presence of acid, strong coordinating ions, and a high oxidation voltage allows nickel atoms to lose electrons rapidly. The applied oxidation voltage feedback signal can then be used to determine electrode failure (before failure, the catalyst causes a very low oxidation voltage, but after failure, the catalyst completely detaches, leaving only the bare nickel wire mesh, which causes the voltage to rise). Combined with ultrasonic treatment, catalysts that are no longer conductive or have poor bonding strength can be shaken off, allowing clear observation of the surface state of the nickel mesh after catalyst detachment.

[0007] Based on the above testing principle, the technical solution adopted by this invention to solve its technical problem is: a testing method for the binding force and uniformity of an electrode catalyst in alkaline water electrolysis for hydrogen production, comprising two processes: experimental equipment setup and experimental operation. The experimental setup includes the following steps: A1: Preparation of test solution A Pure water, 60% sulfuric acid (by mass), and saturated potassium chloride were added to the electrolysis container in a volume ratio of 200:1:1. The mixture was then stirred until homogeneous. The resulting test solution was designated as test solution A. Electrolytic containers of different capacities, such as beakers or electrolytic cells, can be selected according to the amount of solution to be prepared. The amount of solution to be prepared can be determined based on the above proportions and actual needs.

[0008] A 2: Preparation of test solution B Prepare test solution B by mixing pure water and potassium hydroxide in a mass ratio of 100:60: Add pure water to another electrolytic container, then place the beaker into an ultrasonic device, turn on the ultrasonic device, and slowly add potassium hydroxide to the pure water in several batches. Simultaneously, the operator must wear a mask and goggles and continuously stir the solution with a glass rod. After the potassium hydroxide has been completely added, turn off the ultrasonic device. Once the solution temperature in the beaker has decreased (generally to room temperature or when it is no longer hot to the touch), continue adding pure water to bring the volume to twice the original solvent volume. Continue stirring until homogeneous. Record this prepared test solution as test solution B. After the solution is prepared, seal test solution B with plastic wrap or other alkali-resistant material for later use. It is important to note that (1) the mass ratio is 100:60, that is, 60g of potassium hydroxide is added to every 100ml of pure water. Preferably, analytical grade or industrial grade potassium hydroxide is used; (2) pure water is added to balance the volume to twice the original solvent volume. For example: 100ml of pure water is added to 60g of potassium hydroxide. After the temperature drops, pure water is added to make the total volume of the solution 200ml; 150ml of pure water is added to 90g of potassium hydroxide. After the temperature drops, pure water is added to make the total volume of the solution 300ml.

[0009] A3: Preparation of anti-corrosion support plate The corrosion-resistant support plate is made of acid- and alkali-resistant and high-temperature-resistant material, and its length and width must be able to cover the opening of the electrolytic container. A first mounting hole and a second mounting hole for installing electrode clamps are made near the center of the corrosion-resistant support plate, and the center distance between the first and second mounting holes is at least 10mm to ensure that the electrode clamps can test the electrodes in a parallel state. A third mounting hole for installing temperature detection devices is made on the corrosion-resistant support plate away from the first and second mounting holes; the third mounting hole is used to place temperature detection devices such as thermometers or temperature sensors to monitor the solution temperature in real time. The corrosion-resistant support plate is made of acid- and alkali-resistant and high-temperature-resistant plastic sheet; in this embodiment, PTFE sheet is preferred.

[0010] A4: Sample Preparation Prepare the electrode sample and nickel mesh sample to be tested. The electrode sample and nickel mesh sample have the same length and width dimensions. The electrode sample is denoted as sample A. As a preferred option, the required test electrode is cut to 10*15mm and designated as sample A. The nickel mesh is 10*15mm. The nickel mesh does not need to be numbered, but it is necessary to ensure that the nickel mesh is of the same origin in subsequent cutting.

[0011] A5: Assemble and test equipment The electrode sample and the nickel mesh sample are clamped together using platinum electrode clips. The electrode clips are passed through the first and second mounting holes on the anti-corrosion support plate and fixed to the anti-corrosion support plate to assemble a combined electrode frame. The combined electrode frame is placed above the electrolytic container containing test solution A, so that the electrode sample and the nickel mesh sample to be tested are completely immersed in test solution A. At the same time, the temperature detection device is inserted into the third mounting hole and (using an iron stand) the temperature detection device is lifted to ensure that its test area is located in the center area of ​​the electrolytic container. The experimental procedure includes the following steps: B1: Connect the electrode clamps holding the electrode sample and the nickel mesh sample to the output terminal of the regulated power supply through the power clamps, and connect the regulated power supply to the computer through the data cable to automatically record the current data in the test circuit. The polarity of the electrode sample and the nickel mesh sample connected to the regulated power supply is not limited and can be arbitrary. Preferably, the electrode clamp holding the electrode sample is the working electrode, which is connected to the positive output terminal of the regulated power supply via a positive power supply clamp, serving as the anode; the electrode clamp holding the nickel mesh sample is the auxiliary electrode, with its upper end connected to the negative output terminal of the regulated power supply via a negative power supply clamp; preferably, the regulated power supply is used to provide the test voltage and can be an electrochemical workstation or other type of high-precision programmable power supply.

[0012] B2: Turn on the regulated power supply, select the constant potential (regulated voltage) test method, set the test voltage, test time and current data acquisition interval according to the requirements, start the test and record the test data synchronously, save the test data after the test is completed, and plot the corrosion curve based on the test data; B3: Remove the anti-corrosion support plate together with the electrode clamp, electrode sample and nickel mesh sample from the electrolytic container containing test solution A, and clean the electrode clamp, electrode sample and nickel mesh sample with pure water. After rinsing, use lint-free paper to dry the water remaining on the surface, and take a picture of the appearance of the electrode sample, which is recorded as: Appearance A1. B4: Place the electrolytic container containing test solution B into the ultrasonic device, and then place the combined electrode frame (i.e., the anti-corrosion support plate together with the electrode clamp, electrode sample and nickel mesh sample) photographed in step B3 into the test solution B. Turn on the ultrasonic device, and through the vibration of the ultrasonic device, vibrate the catalyst with no binding force or weak binding force on the electrode surface. After vibrating for 10-15 seconds, turn off the ultrasonic device, take out the combined electrode frame, and dry it. After drying, take another picture of the appearance of the electrode sample, and record it as: Appearance A Ultrasonic 1; The drying can be carried out by air drying the electrode at room temperature, or by using a drying device for dehumidification and low temperature vacuum drying.

[0013] B5: Repeat the test process of steps B1-B4 until the collected current data shows a significant change and then tends to stabilize, and the appearance of the electrode sample turns white. At the same time, take a picture to record the appearance of the electrode sample for each test, and record them as: appearance A2, appearance A3... appearance An; appearance A super 2, appearance A super 3... appearance A super n, where n is the number of times the picture is recorded. B6: After the test, process the corrosion curves, overlay all the corrosion curves, and match the corrosion curves of each stage with the appearance of the photographs. Record the color changes and turbidity of test solution A and test solution B after the test. In the actual test, the test solutions are initially colorless, clear and transparent. Generally, the turbidity and color of test solution A will not change much. After standing, catalyst particles that have fallen off can be observed at the bottom of test solution B.

[0014] B7: Repeat steps A1-A5 and B1-B6 to test multiple groups of electrode samples and nickel mesh samples. The electrode samples are: Sample B, Sample C, Sample D, Sample E, etc. Test each group of electrode samples and nickel mesh samples, record the data, plot the corrosion curve, take pictures of the appearance, and record the color change of the solution. After the test, analyze the corrosion curve to obtain the catalyst binding force and uniformity data of the corresponding batch of electrode samples, so as to judge the catalyst binding force and uniformity of the electrode samples. B8: By using the above method to test different types of electrode materials, the catalyst binding force and uniformity between different types of electrode materials can also be compared.

[0015] Preferably, the corrosion-resistant support plate is made of PTFE sheet with a thickness of at least 10 mm.

[0016] Furthermore, the nickel mesh is made of a material with a purity of N6 or higher.

[0017] Specifically, the size of both the electrode sample and the nickel mesh sample is 10*15mm.

[0018] Furthermore, to facilitate the synchronous recording of temperature data, the temperature detection device employs a temperature sensor, which is connected to a computer to automatically record the temperature data. Using a temperature sensor allows for simultaneous and direct reading of temperature data, ensuring temperature stability and improving the accuracy of the test data.

[0019] Furthermore, in step B3, during cleaning, the part of the electrode clamp that is immersed in the solution needs to be cleaned together.

[0020] Furthermore, in order to eliminate factors with low correlation in the test, the process of electrode sample quality testing is also included. Specifically, the mass of the electrode sample is weighed before the test and recorded as M0. After each photo is taken in step B4, the mass of the electrode sample is weighed and recorded as M1, M2, M3...Mn, where n is the number of times the photo is taken.

[0021] It should be noted that after multiple experiments, it was found that the electrode sample quality test procedure has many influencing variables and is quite cumbersome, and is not very meaningful for characterizing the electrode bonding force. Therefore, it can be regarded as a negative factor and excluded from the test, that is, the quality test can be omitted in the subsequent tests.

[0022] The beneficial effects of this invention are as follows: This invention provides a test method for the bonding strength and uniformity of an electrode catalyst in alkaline water electrolysis for hydrogen production. It proposes a test method capable of simulating electrode failure. Compared to traditional test methods, this invention offers a shorter test time, reducing the original test time of over 10,000 hours to one hour or a few hours depending on experimental requirements. The test method is more flexible and, in particular, provides a more intuitive and convenient way to assess the bonding strength between the catalyst and the electrode substrate. Compared to general test methods, this method is more flexible, faster, more convenient, and has lower time and labor costs. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Figure 1 This is a schematic diagram of the structure of the testing device of the present invention.

[0025] Figure 2 These are corrosion curves for different types of electrodes.

[0026] In the figure: 1-Electrolytic container, 2-Anti-corrosion support plate, 3-Working electrode, 4-Auxiliary electrode, 5-Electrode sample, 6-Nickel mesh sample, 7-Temperature detection device, 8-Positive power supply clamp, 9-Negative power supply clamp, 10-Regulated power supply. Detailed Implementation

[0027] The method of the present invention will now be described in detail with reference to specific embodiments.

[0028] This invention discloses a method for testing the binding force and uniformity of an electrode catalyst in alkaline water electrolysis for hydrogen production. The method comprises two processes: experimental equipment setup and experimental operation. The equipment used includes: an ultrasonic oscillator, a digital display stirring and heating platform, an electrochemical workstation (specific equipment parameters can be found in national standard GB / T 45092-2024), a 250ml beaker, and platinum electrode clamps. The two processes are described in detail below with reference to actual operation.

[0029] The experimental setup includes the following steps: preparing test solution A, preparing test solution B, preparing anti-corrosion support plate 2, preparing samples, and assembling the testing equipment. If multiple tests are to be performed, the quantities of test solution A and test solution B can be prepared in sufficient quantities at once for future use, or they can be prepared separately for each test. Sample preparation includes electrode sample 5 and nickel mesh sample 6. Depending on the actual testing requirements, all samples can be prepared at once, or they can be prepared separately. The steps described below are explained in detail.

[0030] A1: Preparation of test solution A In this embodiment, the electrolytic container 1 uses a 250ml beaker to prepare approximately 200ml of test solution A. Therefore, 200ml of pure water, 1ml of 60% sulfuric acid, and 1ml of saturated potassium chloride solution are added to the 250ml beaker. The mixture is then stirred evenly on a digital display stirring and heating platform. The prepared test solution is denoted as test solution A. Electrolytic container 1 can be selected from beakers or electrolytic cells of different capacities depending on the amount of solution to be prepared. The amount of solution to be prepared can be determined according to the above proportions and actual needs.

[0031] A 2: Preparation of test solution B Add 100ml of pure water to a 250ml beaker. Place the beaker in an ultrasonic vibrator and accurately weigh 60g of potassium hydroxide (analytical or industrial grade). Turn on the ultrasonic vibrator and start the equipment. Slowly add the potassium hydroxide to the pure water in several stages. Simultaneously, the operator must wear a mask and goggles and continuously stir with a glass rod. After the potassium hydroxide has been completely added, turn off the ultrasonic equipment. Once the solution temperature in the beaker has decreased, continue adding pure water to bring the volume to 200ml to balance the solution. Continue stirring until homogeneous. Record this prepared test solution as Test Solution B. After preparation, seal Test Solution B with plastic wrap or other alkali-resistant material for later use. In this experiment, slight variations in test solution concentration have little impact on the test results. Therefore, industrial grade potassium hydroxide and the beaker balancing method consistent with the actual operating environment can be used. However, potassium hydroxide releases a large amount of heat during dissolution; never add pure water to the alkali solution to prevent the release of high-temperature alkali vapors during dissolution, which could cause chemical corrosion to the experimenter.

[0032] A 3: Preparation of anti-corrosion support plate 2 In this embodiment, the corrosion-resistant support plate 2 needs to match the opening size of the 250ml beaker. Therefore, a 50*50*10mm PTFE plate is used as the corrosion-resistant support plate 2. Then, three holes are drilled in the PTFE plate, namely the first mounting hole, the second mounting hole, and the third mounting hole. The first mounting hole and the second mounting hole are used to install the electrode clips, which are located near the center of the corrosion-resistant support plate 2. The center distance between the first mounting hole and the second mounting hole is at least 10mm to ensure that the electrode clips can test the electrodes in a parallel state. The third mounting hole is opened at a position of the corrosion-resistant support plate 2 away from the first mounting hole and the second mounting hole for installing the temperature detection device 7. The third mounting hole is used to place the temperature detection device 7, such as a thermometer or temperature sensor, to detect the solution temperature in real time.

[0033] A4: Sample Preparation Prepare the electrode sample 5 and nickel mesh sample 6 to be tested. The electrode sample 5 and nickel mesh sample 6 have the same length and width dimensions. In this embodiment, as a preferred method, the required test electrode is cut to 10*15mm and the nickel mesh is cut to 10*15mm. The nickel mesh does not need to be numbered, but it is necessary to ensure that the nickel mesh is from the same source in subsequent cutting. The nickel mesh material must be N6 or higher purity material. Four electrode samples 5 are prepared and labeled as sample A, sample B, sample C and sample D respectively. There are also four corresponding nickel mesh samples 6.

[0034] A5: Assemble and test equipment like Figure 1 As shown, electrode sample A and nickel mesh sample 6 are clamped together using platinum electrode clips. The electrode clips are passed through the first and second mounting holes on the anti-corrosion support plate 2 and fixed to the anti-corrosion support plate 2 to assemble a combined electrode frame. The combined electrode frame is placed above the electrolytic container 1 containing test solution A, so that the electrode sample 5 and nickel mesh sample 6 to be tested are completely immersed in test solution A. At the same time, the temperature detection device 7 is inserted into the third mounting hole, and the temperature detection device 7 is lifted using an iron stand to ensure that its testing area is located in the central area of ​​the electrolytic container 1.

[0035] The experimental procedure includes the following steps: B1: As Figure 1As shown, the electrode clamps holding electrode sample 5 and nickel mesh sample 6 are connected to the output terminal of regulated power supply 10 via power clamps, and regulated power supply 10 is connected to a computer via a data cable for automatic recording of current data in the test circuit. The positive and negative terminals of electrode sample 5 and nickel mesh sample 6 connected to regulated power supply 10 are not restricted and can be arbitrary. Preferably, in this embodiment, the electrode clamp holding electrode sample 5 is the working electrode 3, which is connected to the positive output terminal of regulated power supply 10 via positive power clamp 8, serving as the anode; the electrode clamp holding nickel mesh sample 6 serves as the auxiliary electrode 4 (i.e., the counter electrode), and the upper end of the auxiliary electrode 4 is connected to the negative output terminal of regulated power supply 10 via negative power clamp 9. Preferably, regulated power supply 10 is used to provide the test voltage; in this embodiment, an electrochemical workstation is used as the regulated power supply. If the temperature detection device 7 is one that can directly record data, it is also connected to the computer. For example, if the temperature detection device 7 is a temperature sensor, the temperature sensor is connected to the computer to automatically record temperature data.

[0036] B2: Turn on the regulated power supply 10, select the constant potential (regulated voltage) test method, and set the test voltage, test time, and current data acquisition interval according to the requirements. In this embodiment, the test voltage is set to 1.8V, which refers to the voltage relative to the working electrode 3. The test time is set to 10min, and the current data acquisition interval is 0.05s. Start the test and record the test data synchronously. After the test is completed, save the test data and plot the corrosion curve based on the test data.

[0037] B3: Remove the anti-corrosion support plate 2 together with the electrode clamp, electrode sample 5 and nickel mesh sample 6 from the electrolytic container 1 containing test solution A, and clean the electrode clamp, electrode sample 5 and nickel mesh sample 6 with pure water. During cleaning, the part of the electrode clamp that is immersed in the solution should also be cleaned. After rinsing, use lint-free paper to dry the water remaining on the surface, and take a picture of the appearance of electrode sample 5, which is recorded as: appearance A1. B4: Place the electrolytic container 1 containing test solution B into the ultrasonic device, and then place the combined electrode frame (i.e., the anti-corrosion support plate 2 together with the electrode clamp, electrode sample 5 and nickel mesh sample 6) photographed in step B3 into the test solution B. Turn on the ultrasonic device, and through the vibration of the ultrasonic device, vibrate the catalyst with no binding force or weak binding force on the electrode surface. After vibrating for 10-15 seconds, turn off the ultrasonic device, take out the combined electrode frame, and dry it. After drying, take another picture of the appearance of electrode sample 5, and record it as: appearance A (ultrasound 1). The drying can be carried out by air drying the electrode at room temperature, or by using a drying device for dehumidification and low-temperature vacuum drying.

[0038] Optionally, the process also includes testing the mass of electrode sample 5. Specifically, the mass of electrode sample 5 is weighed before testing and recorded as M0. After each photograph taken in step B4, the mass of electrode sample 5 is weighed and recorded as M1, M2, and M3, respectively. It should be noted that after multiple experiments, it was found that the mass testing procedure for electrode sample 5 has many influencing variables and is quite cumbersome, and has little significance for characterizing the electrode bonding force. Therefore, it can be considered a negative factor and excluded from testing, meaning that subsequent mass testing can be omitted.

[0039] B5: Repeat the test process of steps B1-B4 until the collected current data shows a significant change and then tends to stabilize, and the appearance of electrode sample 5 turns white. At the same time, take pictures to record the appearance of electrode sample 5 for each test, and record them as: appearance A2, appearance A3; appearance A2, appearance A3. The test records are shown in Table 1.

[0040] Table 1. Mean voltage values ​​after ultrasonic testing

[0041] As shown in Table 1, the first row describes the appearance and powder shedding of each electrode; the second row shows the number of ultrasonic tests; and the third row shows the voltage performance of sample A. For sample A, the voltage value was 2.25V before ultrasonic testing, and 0.80V after 3 ultrasonic tests. As the number of ultrasonic tests increased, the powder shedding increased. Therefore, its voltage performance was initially poor, but improved after ultrasonic testing.

[0042] The fourth row shows the voltage performance of sample B. Before ultrasonic testing, its voltage was 0.79V. After three ultrasonic tests, the voltage was 0.89V. With each ultrasonic test, powder detachment increased; therefore, its voltage performance was initially good but worsened after ultrasonic testing (0.8V is considered complete detachment). The fifth and sixth rows show the voltage performance of samples C and D, respectively, which are similar to those of sample B.

[0043] B6: After the test, process the corrosion curves, overlay all the corrosion curves, and match the corrosion curves of each stage with the appearance of the photographs. Record the color changes and turbidity of test solution A and test solution B after the test. In the actual test, the test solutions are initially colorless, clear and transparent. Generally, the turbidity and color of test solution A will not change much. After standing, catalyst particles that have fallen off can be observed at the bottom of test solution B.

[0044] B7: Repeat steps A1-A5 and B1-B6 to test multiple groups of electrode samples 5 and nickel mesh samples 6. The electrode samples 5 are: sample B, sample C, and sample D. Test each group of electrode samples 5 and nickel mesh samples 6, record the data, plot the corrosion curve, take pictures of the appearance, and record the color change of the solution. After the test, analyze the corrosion curve to obtain the catalyst binding force and uniformity data of the corresponding batch of electrode samples 5, so as to judge the catalyst binding force and uniformity of electrode samples 5.

[0045] B8: By using the above method to test different types of electrode materials, the catalyst binding force and uniformity between different types of electrode materials can also be compared.

[0046] like Figure 2 The figure shows corrosion curves plotted using the testing method of this invention with four different electrodes as examples. The vertical axis represents the current in the test circuit (unit: A), and the horizontal axis represents the test duration (unit: s). The black curve represents electrode 1, a high-performance ceramic spray-coated electrode (40 mesh); electrode 2, a common nickel-aluminum spray-coated electrode (46 mesh); electrode 5, a common nickel-aluminum spray-coated electrode (40 mesh); and electrode 6, a nickel electroplated electrode (40 mesh). The black curve represents the corrosion curve of electrode 1, the red curve represents the corrosion curve of electrode 2, the blue curve represents the corrosion curve of electrode 5, and the green curve represents the corrosion curve of electrode 6. From the curves, it can be seen that the corrosion current of the spray-coated electrode decreases slowly over time, then rapidly decays at around 1000 seconds, and then rises. After stabilizing, the current becomes the corrosion curve of the nickel mesh substrate. The electroplated electrode decays rapidly in a short time and then begins to dissolve the substrate. From the corrosion curves of electrodes 2 and 5, it can be seen that when the substrate mesh size is different, the larger the mesh size, the higher the corresponding current when the substrate dissolves.

[0047] In the design method of this invention, it was observed that the catalytic capacity of the electrode varies with different degrees of detachment. Finally, when the catalyst on the electrode surface is completely detached, the electrode performance curve is expressed in a completely different form.

[0048] The testing of this invention refers to the national standard GB / T 45092-2024 or the long-term test of the small standard alkaline electrolytic cell (the test duration is in "years").

[0049] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the scope of the present invention. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for testing the bonding strength and uniformity of an electrode catalyst in alkaline water electrolysis for hydrogen production, characterized in that: It includes two processes: setting up experimental equipment and conducting experiments. The experimental setup includes the following steps: A1: Preparation of test solution A Pure water, 60% sulfuric acid (by mass), and saturated potassium chloride were added to the electrolysis container in a volume ratio of 200:1:

1. The mixture was then stirred until homogeneous. The resulting test solution was designated as test solution A. A 2: Preparation of test solution B Prepare test solution B by mixing pure water and potassium hydroxide in a mass ratio of 100:60: Add pure water to another electrolytic container, then place the beaker into an ultrasonic device, turn on the ultrasonic device, and slowly add potassium hydroxide to the pure water in several batches while continuously stirring. After the potassium hydroxide has been completely added, turn off the ultrasonic device and wait for the solution temperature in the beaker to drop. Then, continue adding pure water to balance the volume to twice the original solvent volume and continue stirring until homogeneous. This prepared test solution is designated as test solution B. After the solution is prepared, seal test solution B with an alkali-resistant material for later use. A3: Preparation of anti-corrosion support plate The anti-corrosion support plate is made of acid and alkali resistant and high temperature resistant material, and its length and width dimensions must be able to cover the opening of the electrolytic container. A first mounting hole and a second mounting hole for installing electrode clips are opened near the center of the anti-corrosion support plate, and the center distance between the first mounting hole and the second mounting hole is at least 10mm. A third mounting hole for installing temperature detection device is opened at the position of the anti-corrosion support plate away from the first mounting hole and the second mounting hole. A4: Sample Preparation Prepare the electrode sample and nickel mesh sample to be tested. The electrode sample and nickel mesh sample have the same length and width dimensions. The electrode sample is denoted as sample A. A5: Assembly and testing equipment The electrode sample and the nickel mesh sample are clamped together using platinum electrode clips. The electrode clips are passed through the first and second mounting holes on the anti-corrosion support plate and fixed to the anti-corrosion support plate to assemble a combined electrode frame. The combined electrode frame is placed above the electrolytic container containing test solution A, so that the electrode sample and the nickel mesh sample to be tested are completely immersed in test solution A. At the same time, the temperature detection device is inserted into the third mounting hole and suspended to ensure that its test area is located in the center area of ​​the electrolytic container. The experimental procedure includes the following steps: B1: Connect the electrode clamps holding the electrode sample and the nickel mesh sample to the output terminal of the regulated power supply through the power clamps, and connect the regulated power supply to the computer through the data cable to automatically record the current data in the test circuit. B2: Turn on the regulated power supply, select the constant potential test method, set the test voltage, test time and current data acquisition interval according to the requirements, start the test and record the test data synchronously, save the test data after the test is completed, and plot the corrosion curve based on the test data; B3: Remove the anti-corrosion support plate together with the electrode clamp, electrode sample and nickel mesh sample from the electrolytic container containing test solution A, and clean the electrode clamp, electrode sample and nickel mesh sample with pure water. After rinsing, use lint-free paper to dry the water remaining on the surface, and take a picture of the appearance of the electrode sample, which is recorded as: Appearance A1. B4: Place the electrolytic container containing test solution B into the ultrasonic device, then place the combined electrode holder photographed in step B3 into test solution B, turn on the ultrasonic device, vibrate for 10-15 seconds, turn off the ultrasonic device, remove the combined electrode holder, and dry it. After drying, take another photograph of the appearance of the electrode sample, and record it as: Appearance A (Ultra 1). B5: Repeat the test process of steps B1-B4 until the collected current data shows a significant change and then tends to stabilize, and the appearance of the electrode sample turns white. At the same time, take a picture to record the appearance of the electrode sample for each test, and record them as: appearance A2, appearance A3... appearance An; appearance A super 2, appearance A super 3... appearance A super n, where n is the number of times the picture is recorded. B6: After the test, process the corrosion curves, overlay all the corrosion curves, and match the corrosion curves of each stage with the appearance captured in the photograph. Record the color changes and turbidity of test solution A and test solution B after the test. B7: Repeat steps A1-A5 and B1-B6 to test multiple groups of electrode samples and nickel mesh samples. The electrode samples are: Sample B, Sample C, Sample D, Sample E, etc. Test each group of electrode samples and nickel mesh samples, record the data, plot the corrosion curve, take pictures of the appearance, and record the color change of the solution. After the test, analyze the corrosion curve to obtain the catalyst binding force and uniformity data of the corresponding batch of electrode samples, so as to judge the catalyst binding force and uniformity of the electrode samples. B8: The above method was used to test different types of electrode materials, and the catalyst binding force and uniformity between different types of electrode materials were compared.

2. The method for testing the bonding strength and uniformity of the alkaline water electrolysis hydrogen production electrode catalyst as described in claim 1, characterized in that: The corrosion-resistant support plate is made of PTFE sheet with a thickness of at least 10mm.

3. The method for testing the bonding strength and uniformity of the alkaline water electrolysis hydrogen production electrode catalyst as described in claim 1, characterized in that: The nickel mesh is made of a material with a purity of N6 or higher.

4. The method for testing the bonding strength and uniformity of the alkaline water electrolysis hydrogen production electrode catalyst as described in claim 1, characterized in that: The electrode sample and the nickel mesh sample are both 10*15mm in size.

5. The method for testing the bonding strength and uniformity of the alkaline water electrolysis hydrogen production electrode catalyst as described in claim 1, characterized in that: The temperature detection device uses a temperature sensor, which is connected to a computer to automatically record temperature data.

6. The method for testing the bonding strength and uniformity of the alkaline water electrolysis hydrogen production electrode catalyst as described in claim 1, characterized in that: In step B3, during cleaning, the part of the electrode clamp that is immersed in the solution should also be cleaned.

7. The method for testing the bonding strength and uniformity of the alkaline water electrolysis hydrogen production electrode catalyst as described in any one of claims 1-6, characterized in that: It also includes the process of electrode sample quality testing, specifically: before the test, the mass of the electrode sample is weighed and recorded as M0. After each photo is taken in step B4, the mass of the electrode sample is weighed and recorded as M1, M2, M3...Mn, where n is the number of times the photo is taken.

Images