Method for testing ion exchange equivalent of proton exchange membrane
The method of detecting the ion exchange equivalent of proton exchange membranes using a chemical adsorption instrument and ammonia reaction method solves the problems of long testing cycles and large errors in existing testing methods, and achieves rapid and accurate test results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-27
- Publication Date
- 2026-03-27
AI Technical Summary
Existing methods for testing the ion exchange equivalent of proton exchange membranes are time-consuming and prone to large errors, mainly due to the high density of proton exchange membranes requiring long-term immersion and manual determination of titration endpoints.
The method employs a chemisorption analyzer and an ammonia reaction method. The proton exchange membrane is cut into fragments and reacted with a mixture of ammonia and nitrogen in a U-shaped tube. The temperature is controlled below 90℃. The amount of ammonia adsorbed is detected by the chemisorption analyzer to calculate the ion exchange equivalent, thus avoiding the need for manual determination of the titration endpoint.
It significantly shortens the testing cycle, improves testing accuracy and efficiency, achieves automated endpoint determination, and reduces human error.
Smart Images
Figure CN121741104A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of proton exchange membrane fuel cell technology, and more specifically, to a method for testing the ion exchange equivalent of a proton exchange membrane. Background Technology
[0002] Proton exchange membrane fuel cells (PEMFCs) typically have an energy conversion efficiency of 40%–60%, making them highly efficient devices. They can directly convert the chemical energy of hydrogen and oxygen into electrical energy through electrochemical reactions, with water as the only byproduct, making them environmentally friendly. The main function of the proton exchange membrane (PEM) in a PEMFC is to conduct protons and isolate electrons, while also providing support for other components. It is a key component of the PEMFC, and the ion exchange equivalent weight (EW) of the PEM is used to assess its ion conductivity, hydration, mechanical stability, and chemical stability, playing a crucial role in evaluating its performance.
[0003] Currently, the test method for the ion exchange equivalent of proton exchange membranes is usually titration. However, proton exchange membranes are highly compact and require thorough soaking to fully expose the acid radicals, resulting in a long test cycle of at least 8 hours. In addition, since the titration is done manually and the determination of the titration endpoint varies from person to person, the test error is relatively large. Summary of the Invention
[0004] The main objective of this invention is to provide a method for testing the ion exchange equivalent of proton exchange membranes, so as to solve the problems of long testing cycles and large testing errors in the current method for testing the ion exchange equivalent of proton exchange membranes.
[0005] To achieve the above objectives, according to a first aspect of the present invention, a method for testing the ion exchange equivalent of a proton exchange membrane is provided, comprising the following steps:
[0006] S1, the proton exchange membrane to be tested is cut into fragments to obtain the first material;
[0007] S2, insert the support substrate into the U-shaped tube, and then add the first material into the U-shaped tube from the gas inlet end of the U-shaped tube; the location of the support substrate includes the variable diameter section of the U-shaped tube;
[0008] S3, connect the gas outlet end of the U-shaped tube to the sensor in the chemical adsorption instrument, and introduce ammonia or a mixture of ammonia and nitrogen into the U-shaped tube from the gas inlet end of the U-shaped tube to make the first material react with ammonia. Control the reaction temperature ≤90℃, and obtain the ammonia adsorption amount through the chemical adsorption instrument.
[0009] S4, the ion exchange equivalent of the proton exchange membrane is calculated based on the ammonia adsorption capacity;
[0010] In S2, the supporting matrix is used to prevent the first material from being blown away by the gas from the gas outlet end of the U-shaped tube; the porosity of the supporting matrix is 30% to 70%.
[0011] Furthermore, the thickness of the supporting substrate is 1cm to 2cm.
[0012] Furthermore, the material supporting the substrate is quartz wool.
[0013] Furthermore, the diameter of the straight section of the U-shaped tube is 0.5cm to 1.5cm; in S1, the size of the fragment is 0.5mm to 5mm.
[0014] Furthermore, the density of quartz wool is 1.2 g / cm³. 3 ~2g / cm 3 .
[0015] Furthermore, the porosity of asbestos is 30%–60%.
[0016] Furthermore, in S2, the amount of the first material added is 0.1g to 0.2g.
[0017] Furthermore, in S3, ammonia or a mixture of ammonia and nitrogen is introduced into the U-tube from the gas inlet end at a flow rate of 50 mL / min to 300 mL / min.
[0018] Furthermore, in S3, the volume ratio of ammonia to nitrogen in the mixture is (70-80):(20-30).
[0019] Furthermore, in S3, the reaction is carried out at 60–90°C.
[0020] Furthermore, in step S3, the chemical adsorption instrument is preheated before the gas is introduced into the U-shaped tube.
[0021] The scheme disclosed in this invention allows for the rapid detection of acid radical content in proton exchange membranes using a chemisorption analyzer. The reaction endpoint can be directly obtained from the chemisorption analyzer without human intervention. Furthermore, this invention limits the testing steps and conditions, significantly improving testing efficiency and shortening the testing cycle while ensuring testing accuracy, thus enabling industrial applications. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of a U-shaped tube in one embodiment of the present invention;
[0023] Figure 2 This is a schematic diagram of a support substrate placed in a U-shaped tube according to one embodiment of the present invention;
[0024] The above figures contain the following reference numerals:
[0025] 1. Straight pipe section; 2. Variable diameter section; 3. Supporting substrate. Detailed Implementation
[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.
[0027] As described in the background section of this invention, the current method for testing the ion exchange equivalent of proton exchange membranes is titration. This involves titrating with a sodium hydroxide solution of a certain concentration. Once the solution reaches neutrality, the amount of sodium hydroxide consumed is calculated, and then the acid content in the proton exchange membrane is calculated. However, this method has a long testing cycle and is performed manually, which introduces significant human error. The titration endpoint is determined by whether phenolphthalein changes color, which varies from person to person and leads to considerable error.
[0028] To address the aforementioned technical problems, in a typical embodiment of the present invention, a method for testing the ion exchange equivalent of a proton exchange membrane is provided, comprising the following steps:
[0029] S1, the proton exchange membrane to be tested is cut into fragments to obtain the first material;
[0030] S2, insert the support substrate into the U-shaped tube, and then add the first material into the U-shaped tube from the gas inlet end of the U-shaped tube; the location of the support substrate includes the variable diameter section of the U-shaped tube;
[0031] S3, connect the gas outlet end of the U-shaped tube to the sensor in the chemical adsorption instrument, and introduce ammonia or a mixture of ammonia and nitrogen into the U-shaped tube from the gas inlet end of the U-shaped tube to make the first material react with ammonia. Control the reaction temperature ≤90℃, and obtain the ammonia adsorption amount through the chemical adsorption instrument.
[0032] S4, the ion exchange equivalent of the proton exchange membrane is calculated based on the ammonia adsorption capacity;
[0033] In S2, the supporting matrix is used to prevent the first material from being blown away by the gas from the gas outlet end of the U-shaped tube; the porosity of the supporting matrix is 30% to 60%.
[0034] Porosity of a material refers to the percentage of the volume of pores within the material to the total volume of the material, denoted by P. Porosity determination is based on Archimedes' principle. In this experiment, the porosity of quartz wool was determined using the boiling water method. First, the dry weight of the test sample was weighed and recorded as m0. The weighed sample was placed in a clean beaker, and distilled water was poured into the beaker until the sample was submerged. The beaker was then heated to boiling on an electric stove and maintained at boiling for 2 hours to allow the distilled water to completely penetrate the pores in the quartz wool. Heating was then stopped, and the sample was allowed to cool to room temperature. The sample was then quickly removed and placed in a pre-prepared weighing basket, which was hung on the hook of a balance, allowing the sample to remain submerged in water. The suspended weight of the saturated sample in water was weighed and recorded as m1. The saturated sample was removed, and the water on its surface was carefully wiped away with a damp cloth. The mass of the saturated sample was quickly weighed and recorded as m2. The porosity P of the electrode was calculated using the following formula:
[0035] P = (m2 - m0) / (m2 - m1).
[0036] like Figure 1 As shown, the "U-shaped tube" of this invention has a "straight section" and a "variable diameter section." In the description of this invention, the "straight section" has no corners, while the "variable diameter section" is located at a corner, where the diameter of the tube changes. Placing the support substrate in the variable diameter section increases the resistance to movement of the support substrate within the tube, reducing the risk of the first material being blown out of the U-shaped tube by gas. Cutting the proton exchange membrane into fragments facilitates material feeding and prevents the proton exchange membrane from getting stuck in the U-shaped tube, affecting gas flow. After the first material is added to the U-shaped tube, it rests against the support substrate under the action of the gas, which helps the acid radical ions in the proton exchange membrane to fully react with ammonia. Furthermore, controlling the porosity of the support substrate allows the gas to pass smoothly through the support substrate and flow out from the gas outlet end of the U-shaped tube, avoiding any impact on the accuracy and testing cycle of the proton exchange membrane ion exchange equivalent. Controlling the reaction temperature ensures that the proton exchange membrane is in a stable state, avoiding interference with the reaction between acid radical ions and ammonia. This invention is the first to use a chemisorption analyzer to test the ion exchange equivalent of a proton exchange membrane. By limiting the test steps and conditions, the test cycle for ion exchange equivalent can be significantly reduced, and the test efficiency can be improved. In addition, the test process and the determination of the test endpoint are executed by machine and are not affected by human intervention, so the error is small and the test accuracy is high.
[0037] In some implementations, the thickness of the supporting substrate is 1cm to 2cm.
[0038] In the description of this invention, the thickness direction of the supporting substrate is parallel to or perpendicular to the gas flow direction.
[0039] In some embodiments, the substrate material is quartz wool. Quartz wool has a certain porosity, is easy to process into a substrate with the required dimensions and performance parameters, and has good temperature resistance and a wide operating temperature range.
[0040] In some embodiments, in S1, the size of the fragment is 0.5 mm to 5 mm.
[0041] Controlling the size of the fragments within the aforementioned range serves two purposes: firstly, to ensure that all fragments can rest against the support substrate within the U-tube, allowing for a full reaction between the acid radicals in the proton exchange membrane and ammonia; and secondly, to increase the contact area between ammonia and the proton exchange membrane fragments, thereby improving reaction efficiency and shortening the testing cycle.
[0042] In some embodiments, the density of the quartz wool is 1.2 g / cm³. 3 ~2g / cm 3 The porosity of quartz wool is 30% to 60%.
[0043] Controlling the density and porosity of quartz wool within the above-mentioned range helps to further improve testing efficiency and accuracy.
[0044] In some implementations, the diameter of the straight section of the U-shaped pipe is 0.5cm to 1.5cm.
[0045] Controlling the diameter of the straight section of the U-tube is to match it with the supporting substrate. This allows the gas to flow smoothly inside the tube and keeps the supporting substrate structurally stable, thus improving testing accuracy.
[0046] like Figure 2 As shown, in some embodiments, the support substrate is located in the U-shaped tube near the gas outlet end. This limitation on the location of the support substrate is intended to further improve the structural stability of the support substrate in the U-shaped tube, increase the reaction rate between the first material and ammonia, and shorten the testing cycle.
[0047] In some embodiments, in S2, the amount of the first material added is 0.1g to 0.2g.
[0048] Controlling the amount of the first material added is to ensure that the gas in the U-tube can flow smoothly, and at the same time, the acid radical ions in the proton exchange membrane can react quickly with ammonia, thereby improving the testing efficiency.
[0049] In some embodiments, in S3, ammonia or a mixture of ammonia and nitrogen is introduced into the U-tube from the gas inlet end of the U-tube at a flow rate of 50 mL / min to 300 mL / min.
[0050] Controlling the gas flow rate is to ensure that the acid radicals can be completely replaced, while maintaining high accuracy in ion exchange equivalent testing.
[0051] In some embodiments, in S3, the volume ratio of ammonia to nitrogen in the mixture is (70-80):(20-30).
[0052] In this invention, ammonia is used as the reactant gas and nitrogen is used as the carrier gas. Nitrogen can dilute ammonia and improve the accuracy of the test. In addition, controlling the volume ratio of the two can also improve the reaction efficiency.
[0053] In some embodiments, in step S3, the reaction is carried out at 60–90°C. Controlling the reaction temperature helps to further improve reaction efficiency and shorten the reaction cycle.
[0054] When testing under heating conditions, the thermocouple can be placed in the U-tube near the first material (the thermocouple does not contact the first material or the U-tube).
[0055] In some embodiments, in step S3, the chemisorption apparatus is preheated before the gas is introduced into the U-tube.
[0056] Preheating includes equipment self-checks, such as checking whether each valve and sensor is operating normally and whether the gas pressure is up to standard, to bring the equipment into optimal condition. Preheating can be carried out at room temperature.
[0057] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.
[0058] Some of the materials used in the examples and comparative examples are as follows:
[0059] Proton exchange membrane: perfluorosulfonic acid proton exchange membrane;
[0060] Quartz wool A: Thickness 1.5cm, density 1.5g / cm³ 3 The porosity is 60%.
[0061] Quartz wool B: 1cm thick, 1.2g / cm³ 3 The porosity is 40%.
[0062] Quartz wool C: 2cm thick, 2g / cm³ 3 The porosity is 55%;
[0063] Quartz wool D: Thickness 1.5cm, density 2g / cm³ 3 The porosity is 70%.
[0064] Quartz wool E: 1cm thick, 1.0g / cm³3 The porosity is 45%.
[0065] U-shaped pipe: The diameter of the straight pipe section is 1cm.
[0066] Example 1
[0067] An embodiment of the method for testing the ion exchange equivalent of a proton exchange membrane according to the present invention includes the following steps:
[0068] S1, cut the proton exchange membrane into fragments with a size ≤ 5mm, compact them, and obtain the first material;
[0069] S2, Place the quartz wool A into the U-shaped tube, as shown in the structural diagram below. Figure 2 As shown, 0.1g of the first material is then added into the U-shaped tube from the gas inlet end;
[0070] S3. Preheat the chemisorption apparatus at room temperature (check that all valves and sensors are functioning properly and that the gas pressure is within the specified range). Connect the gas outlet end of the U-tube to the sensor in the chemisorption apparatus. Mix ammonia and nitrogen to obtain a mixed gas of ammonia and nitrogen with a volume ratio of 70:30. Control the flow rate of the mixed gas of ammonia and nitrogen into the U-tube to be 200 mL / min. After the reaction is complete, the absorption peak height drops to 0. Obtain the amount of ammonia adsorbed from the chemisorption apparatus.
[0071] S4. The ion exchange equivalent of the proton exchange membrane is calculated based on the ammonia adsorption amount. The absorption peak is integrated using software to calculate the acid content.
[0072] Examples 2-5
[0073] Examples 2-5 are the test methods for the ion exchange equivalent of the proton exchange membrane of the present invention. The only difference between Examples 2-5 and Example 1 is that the types of supporting substrates are different. The supporting substrate in Example 2 is quartz wool B; the supporting substrate in Example 3 is quartz wool C; the supporting substrate in Example 4 is quartz wool D; and the supporting substrate in Example 5 is quartz wool E.
[0074] Example 6
[0075] An embodiment of the method for testing the ion exchange equivalent of a proton exchange membrane according to the present invention includes the following steps:
[0076] S1, cut the proton exchange membrane into fragments with a size ≤ 5mm, compress the fragments into tablets to obtain the first material;
[0077] S2, Place the quartz wool A into the U-shaped tube, as shown in the structural diagram below. Figure 2As shown, 0.15g of the first material is then added into the U-shaped tube from the gas inlet end;
[0078] S3. Preheat the chemisorption apparatus at room temperature (check that all valves and sensors are functioning properly and that the gas pressure is within the specified range). Connect the gas outlet end of the U-tube to the sensor in the chemisorption apparatus. Mix ammonia and nitrogen to obtain a mixed gas of ammonia and nitrogen with a volume ratio of 70:30. Control the flow rate of the mixed gas of ammonia and nitrogen into the U-tube to be 150 mL / min. After the reaction is complete, obtain the amount of ammonia adsorbed from the chemisorption apparatus.
[0079] S4, the ion exchange equivalent of the proton exchange membrane is calculated based on the amount of ammonia adsorbed.
[0080] Example 7
[0081] An embodiment of the method for testing the ion exchange equivalent of a proton exchange membrane according to the present invention includes the following steps:
[0082] S1, cut the proton exchange membrane into fragments with a size ≤ 5mm, compress the fragments into tablets to obtain the first material;
[0083] S2, Place the quartz wool A into the U-shaped tube, as shown in the structural diagram below. Figure 2 As shown, 0.2g of the first material is then added into the U-shaped tube from the gas inlet end;
[0084] S3. Preheat the chemisorption apparatus at room temperature (check that all valves and sensors are functioning properly and that the gas pressure is within the specified range). Connect the gas outlet end of the U-tube to the sensor in the chemisorption apparatus. Mix ammonia and nitrogen to obtain a mixed gas of ammonia and nitrogen with a volume ratio of 70:30. Control the flow rate of the mixed gas of ammonia and nitrogen into the U-tube to be 300 mL / min. After the reaction is complete, obtain the amount of ammonia adsorbed from the chemisorption apparatus.
[0085] S4, the ion exchange equivalent of the proton exchange membrane is calculated based on the amount of ammonia adsorbed.
[0086] Examples 8-10
[0087] Examples 8-10 are the test methods for the ion exchange equivalent of the proton exchange membrane of the present invention. The only difference between the test methods described in Examples 8-10 and Example 1 is that the volume ratio of ammonia to nitrogen in S3 is different; the volume ratio of ammonia to nitrogen in Example 8 is 75:25, the volume ratio of ammonia to nitrogen in Example 9 is 80:20, and the volume ratio of ammonia to nitrogen in Example 10 is 50:50.
[0088] Example 11
[0089] An embodiment of the method for testing the ion exchange equivalent of a proton exchange membrane according to the present invention includes the following steps:
[0090] S1, cut the proton exchange membrane into fragments with a size ≤ 5mm, compress the fragments into tablets to obtain the first material;
[0091] S2, Place the quartz wool A into the U-shaped tube, as shown in the structural diagram below. Figure 2 As shown, 0.1g of the first material is then added into the U-shaped tube from the gas inlet end;
[0092] S3. Preheat the chemisorption apparatus at room temperature (check that all valves and sensors are functioning properly and that the gas pressure is within the specified range). Connect the gas outlet end of the U-tube to the sensor in the chemisorption apparatus. Input ammonia gas into the U-tube from the gas inlet end of the U-tube and control the ammonia gas input flow rate to 200 mL / min. After the reaction is complete, obtain the amount of ammonia gas adsorbed from the chemisorption apparatus.
[0093] S4, the ion exchange equivalent of the proton exchange membrane is calculated based on the amount of ammonia adsorbed.
[0094] Example 12
[0095] An embodiment of the method for testing the ion exchange equivalent of a proton exchange membrane according to the present invention includes the following steps:
[0096] S1, cut the proton exchange membrane into fragments with a size ≤ 5mm, compress the fragments into tablets to obtain the first material;
[0097] S2, Place the quartz wool A into the U-shaped tube, as shown in the structural diagram below. Figure 2 As shown, 0.1g of the first material is then added into the U-shaped tube from the gas inlet end;
[0098] S3. Preheat the chemisorption apparatus at room temperature (check that all valves and sensors are functioning properly and that the gas pressure is within the specified range). Place the thermocouple in the U-tube near the substrate (without contacting the substrate, the first material, or the U-tube). Connect the gas outlet end of the U-tube to the sensor in the chemisorption apparatus. Heat the U-tube until the temperature detected by the thermocouple reaches 90°C. Maintain this temperature. Mix ammonia and nitrogen to obtain a mixed gas of ammonia and nitrogen with a volume ratio of 70:30. Control the flow rate of the mixed gas of ammonia and nitrogen into the U-tube to be 200 mL / min. After the reaction is complete, obtain the amount of ammonia adsorbed from the chemisorption apparatus.
[0099] S4, the ion exchange equivalent of the proton exchange membrane is calculated based on the amount of ammonia adsorbed.
[0100] Example 13
[0101] This invention provides an embodiment of a method for testing the ion exchange equivalent of a proton exchange membrane. The difference between this embodiment and embodiment 12 is that, in step S3, the temperature is adjusted from 90°C to 60°C.
[0102] Comparative Example 1
[0103] A method for testing the ion exchange equivalent of a proton exchange membrane includes the following steps:
[0104] S1, Sample pretreatment: Place the proton exchange membrane in an 80℃ oven and dry for 2 hours, then weigh the dry membrane.
[0105] S2, N2 is bubbled into deionized water for 30 min, 0.1 g of proton exchange membrane dry membrane is added to the deionized water and stirred for 15 min, then 55 mL of saturated NaCl aqueous solution is added and stirred for 45 min.
[0106] S3. Prepare a NaOH solution according to the specified ratio, and standardize the prepared NaOH solution with potassium hydrogen phthalate to a concentration of C. (NaOH) ;
[0107] S4. Use a calibrated sodium hydroxide solution with a concentration of 0.00671 mol / L to perform acid-base titration. When the solution changes from colorless to light pink, record the amount of NaOH solution consumed, V.
[0108]
[0109] Comparative Example 2
[0110] A method for testing the ion exchange equivalent of a proton exchange membrane, the only difference between this method and Example 12 is that, in S3, 90°C is adjusted to 95°C.
[0111] The performance test results of the examples and comparative examples are shown in Table 1.
[0112] Table 1
[0113] project Ion exchange equivalent (g / mol) Test duration (h) Example 1 933 2 Example 2 1015 2 Example 3 1068 1.5 Example 4 1245 2 Example 5 1135 1 Example 6 1203 2 Example 7 1134 2.5 Example 8 1145 1.5 Example 9 1129 1.5 Example 10 1450 3.5 Example 11 1243 1 Example 12 1115 1 Example 13 1042 1.5 Comparative Example 1 945 10 Comparative Example 2 2145 1
[0114] As shown in Table 1, the method described in this embodiment of the invention can be used to test the ion exchange equivalent of proton exchange membranes within 3.5 hours, which significantly reduces the testing time compared to the traditional titration method (Comparative Example 1), thus improving testing efficiency. In Comparative Example 2, the reaction temperature is higher than 90°C, causing cross-linking of the proton exchange membrane and a sharp increase in testing error.
[0115] Furthermore, comparing the test results of Examples 1-4, it can be found that when the porosity of the quartz wool is 30%-60%, the test time can be controlled within 3 hours, and the test accuracy is high. Additionally, comparing the test results of Examples 1 and 5, it can be found that the density of the quartz wool is 1.2 g / cm³. 3 ~2g / cm 3 At that time, the test accuracy is higher.
[0116] Comparing the test results of Examples 1 and 8-11, it can be found that the test accuracy is higher when the volume ratio of ammonia to nitrogen in the mixture of ammonia and nitrogen is (70-80):(20-30).
[0117] Comparing the test results of Examples 1 and 12-13, it can be found that by heating, the test time can be significantly reduced and the test efficiency can be significantly improved while ensuring good test accuracy.
[0118] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. 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 method for testing the ion exchange equivalent of a proton exchange membrane, characterized in that, Includes the following steps: S1, the proton exchange membrane to be tested is cut into fragments to obtain the first material; S2, insert the support substrate into the U-shaped tube, and then add the first material into the U-shaped tube from the gas inlet end of the U-shaped tube; the location of the support substrate includes the variable diameter section of the U-shaped tube; S3, connect the gas outlet end of the U-shaped tube to the sensor in the chemical adsorption instrument, and introduce ammonia or a mixture of ammonia and nitrogen into the U-shaped tube from the gas inlet end of the U-shaped tube to make the first material and the ammonia react, control the reaction temperature ≤90℃, and obtain the ammonia adsorption amount through the chemical adsorption instrument. S4, calculate the ion exchange equivalent of the proton exchange membrane based on the ammonia adsorption amount; In step S2, the supporting substrate is used to prevent the first material from being blown away by the gas from the gas outlet end of the U-shaped tube, and the porosity of the supporting substrate is 30% to 70%.
2. The method for testing the ion exchange equivalent of a proton exchange membrane according to claim 1, characterized in that, The thickness of the supporting substrate is 1cm to 2cm.
3. The method for testing the ion exchange equivalent of a proton exchange membrane according to claim 2, characterized in that, The material of the supporting substrate is quartz wool.
4. The method for testing the ion exchange equivalent of a proton exchange membrane according to claim 3, characterized in that, The diameter of the straight section of the U-shaped tube is 0.5cm to 1.5cm; in S1, the size of the fragment is 0.5mm to 5mm; and / or, the density of the quartz wool is 1.2g / cm³. 3 ~2g / cm 3 ; and / or, the porosity of the quartz wool is 30% to 60%.
5. The method for testing the ion exchange equivalent of a proton exchange membrane according to any one of claims 1 to 4, characterized in that, In step S2, the amount of the first material added is 0.1g to 0.2g.
6. The method for testing the ion exchange equivalent of a proton exchange membrane according to any one of claims 1 to 4, characterized in that, In step S3, the flow rate of ammonia or a mixture of ammonia and nitrogen gas into the U-shaped tube from the gas inlet end of the U-shaped tube is 50 mL / min to 300 mL / min.
7. The method for testing the ion exchange equivalent of a proton exchange membrane according to claim 6, characterized in that, In S3, the volume ratio of ammonia to nitrogen in the mixture is (70-80):(20-30).
8. The method for testing the ion exchange equivalent of a proton exchange membrane according to any one of claims 1 to 4, characterized in that, In step S3, the reaction is carried out at 60–90°C.
9. The method for testing the ion exchange equivalent of a proton exchange membrane according to any one of claims 1 to 4, characterized in that, In step S3, the chemical adsorption instrument is preheated before the gas is introduced into the U-shaped tube.