Electrochemical evaluation device for catalyst in high-temperature environment

Abstract

The utility model discloses an electrochemical evaluation device for a catalyst in a high-temperature environment, and belongs to the technical field of electro-catalysis evaluation. According to the electrochemical evaluation device disclosed by the utility model, the electrochemical reaction unit, the high-temperature and high-pressure circulating unit and the independent reference electrode unit are arranged, so that the temperature of the electrolyte in the electrolytic tank can be always kept at the set temperature in the testing process, and the electrolyte is not evaporated at the high temperature of more than 100 DEG C; and the stability of the acquired data is further improved, so that the evaluation requirement of the catalyst under the working condition of high temperature of 150 DEG C at most is met, the performance and durability of the catalyst in practical application are ensured, and the technical problem that the existing evaluation device is difficult to meet the evaluation requirement of the catalyst under the condition of 100 DEG C or above is solved.

Description

Technical Field

[0001] This invention belongs to the field of electrocatalysis evaluation technology, specifically relating to an electrochemical evaluation device for catalysts in a high-temperature environment. Background Technology

[0002] The catalyst is a core component of the membrane electrode assembly (MEA) in a proton exchange membrane fuel cell (PEMFC). Its material properties include electrochemical activity, conductivity, specific surface area, porosity, chemical stability, and mechanical strength. These characteristics directly determine the overall performance of the PEMFC, such as open-circuit voltage, power density, current output stability, and energy conversion efficiency. They also significantly affect the durability and reliability of the fuel cell system during long-term operation. Because the catalyst must simultaneously perform multiple functions during fuel cell operation, including redox reaction catalysis, proton conduction, electron transport, and gas diffusion, and faces a series of degradation mechanisms under harsh electrochemical environments, such as catalyst particle agglomeration, support corrosion, and active site deactivation, a comprehensive and systematic performance evaluation and durability test must be conducted before the catalyst is fabricated into a complete MEA assembly. The specific evaluation includes, but is not limited to: determining the electrochemical active area and intrinsic catalytic activity of the catalyst using a rotating disk electrode testing system; simulating catalyst degradation behavior under actual operating conditions through accelerated stress testing; analyzing the stability of the catalyst crystal structure using X-ray diffraction; observing changes in catalyst particle size and dispersion using transmission electron microscopy; analyzing changes in proton conduction and charge transfer resistance of the catalyst layer using electrochemical impedance spectroscopy; and also examining the performance degradation law of the catalyst under different humidity, temperature, and operating potential conditions. These systematic characterization and evaluation works are of great guiding significance for optimizing catalyst material design, improving preparation processes, and predicting the service life of membrane electrode assemblies in actual fuel cell systems. Only high-performance catalyst materials that have undergone rigorous screening and evaluation can ensure that the finally prepared proton exchange membrane fuel cell membrane electrode assemblies have excellent electrochemical performance and long-term operational stability.

[0003] With the continuous development of proton exchange membrane fuel cell technology, its operating temperature range is constantly expanding. The maximum operating temperature has gradually increased from the current mainstream 92℃ to high-temperature conditions of 105℃ and even 120℃. While this temperature increase helps improve the thermal management efficiency of the battery system, enhances electrochemical reaction kinetics, and strengthens the tolerance to poisoning impurities such as carbon monoxide, it also places more stringent requirements on electrochemical testing methods and evaluation systems. To more accurately reflect the true performance of the catalyst in real-world application environments, it is necessary to simulate complex operating conditions such as high temperature, high humidity, and dynamic load during testing, and to adopt test parameters that are closer to the actual fuel cell operating environment. This includes improving the temperature control accuracy of the testing system, optimizing the thermal stability of the gas diffusion layer, and enhancing the water retention capacity of the proton exchange membrane at high temperatures. This ensures that the evaluation results of catalyst activity, stability, and durability have higher reliability and guiding value. As the core functional material of proton exchange membrane fuel cells, the intrinsic catalytic activity, electrochemical stability, and resistance to degradation directly determine key performance indicators such as output power density, energy conversion efficiency, and long-term operating life. Therefore, developing catalyst materials with higher intrinsic activity, better chemical stability, and stronger resistance to sintering can not only significantly improve the catalytic efficiency of oxygen reduction and hydrogen oxidation reactions and reduce electrochemical polarization losses, but also effectively extend the service life of membrane electrodes, thereby reducing the overall operating cost of fuel cell systems. This is of great strategic significance for promoting the commercial application of proton exchange membrane fuel cell technology.

[0004] However, the operating conditions of high-temperature catalytic reaction systems are extremely harsh, especially in extreme environments where the operating temperature exceeds 100°C. The liquid electrolyte system inside a proton exchange membrane fuel cell faces severe solvent evaporation, leading to dehydration of the membrane electrode assembly. This, in turn, causes a series of negative effects such as decreased proton conductivity and increased interfacial contact resistance. Simultaneously, the high-temperature environment accelerates the sintering and agglomeration of the catalyst's active components and the corrosion and degradation of the support material, resulting in irreversible deterioration of the catalyst layer's microstructure and chemical stability. Current conventional catalyst performance evaluation methods are mainly based on electrochemical testing systems under ambient temperature and pressure conditions. The test parameter settings and experimental condition control are insufficient to realistically simulate the complex environmental characteristics under high-temperature operating conditions, especially under harsh conditions exceeding 100°C. Existing testing methods have significant shortcomings in temperature uniformity control, precise humidity adjustment, and maintenance of the thermal stability of the gas diffusion layer, making it impossible to comprehensively and accurately assess the intrinsic activity decay law and long-term durability of catalysts in high-temperature, low-humidity, and highly corrosive environments. The severe disconnect between these testing conditions and actual operating conditions makes it difficult for experimental data to effectively guide the material design and process optimization of catalysts for high-temperature proton exchange membrane fuel cells. There is an urgent need to establish a catalyst evaluation system that can accurately simulate high-temperature operating environments and has the ability to coordinate and control multiple parameters, so as to meet the development needs of next-generation high-temperature proton exchange membrane fuel cells for high-performance catalysts. Utility Model Content

[0005] The purpose of this invention is to provide a high-temperature environment catalyst electrochemical evaluation device to solve the technical problem that existing evaluation devices are unable to meet the catalyst evaluation requirements under conditions above 100°C.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This utility model discloses a high-temperature environment catalyst electrochemical evaluation device, comprising:

[0008] An electrochemical reaction unit, comprising an electrolytic cell, a working electrode, and a counter electrode; one end of the working electrode and the counter electrode are inserted into the electrolyte within the electrolytic cell; a venting pipe is also inserted into the electrolyte within the electrolytic cell;

[0009] The high-temperature and high-pressure circulation unit includes a constant-temperature liquid tank, a jacketed reactor, and an air compressor; the electrolytic cell is located inside the jacketed reactor and a gap is left between it and the inner sidewall of the jacketed reactor; the constant-temperature liquid tank and the air compressor are both located outside the jacketed reactor and are connected to the gap inside the jacketed reactor through pipelines.

[0010] An independent reference electrode unit, which is used to ensure stable data acquisition, is located outside the jacketed reactor.

[0011] Furthermore, the working electrode includes a rotating disk electrode, an electrode shaft, and an electrode interface; one end of the electrode shaft is inserted into the electrolyte in the electrolytic cell, and the other end is connected to the electrode interface; the rotating disk electrode is disposed on one end of the electrode shaft.

[0012] One end of the counter electrode is inserted into the electrolyte in the electrolytic cell, and the other end is connected to the electrode interface.

[0013] Furthermore, the independent reference electrode unit includes an independent electrolytic cell and a reference electrode; the independent electrolytic cell is disposed outside the jacketed reactor, one end of the reference electrode is inserted into the electrolyte in the independent electrolytic cell, and the other end is connected to the electrode interface.

[0014] Furthermore, the high-temperature and high-pressure circulation unit also includes a circulating liquid pump; the jacketed reactor is provided with a liquid inlet and a liquid outlet on both sides respectively; the outlet of the constant-temperature liquid tank is connected to the inlet of the circulating liquid pump through a pipeline, the outlet of the circulating liquid pump is connected to the liquid inlet through a pipeline; and the liquid outlet is connected to the inlet of the constant-temperature liquid tank through a pipeline.

[0015] Furthermore, the jacketed reactor is also provided with a gas inlet and a gas outlet; the gas inlet is connected to the air compressor through an inlet pipe.

[0016] Furthermore, the gas inlet and gas outlet are positioned at higher heights than the liquid inlet and liquid outlet on the jacketed reactor.

[0017] Furthermore, the liquid outlet is located at the top of the jacketed reactor.

[0018] Furthermore, a sealing ring is provided at the top of the jacketed reactor; one end of both the working electrode and the counter electrode passes through the sealing ring and is inserted into the electrolyte in the electrolytic cell; and both the working electrode and the counter electrode are sealed and connected to the sealing ring.

[0019] Furthermore, the gas pressure inside the jacketed reactor is above 2 MPa.

[0020] Furthermore, the circulating liquid pump is a circulating peristaltic pump.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] This invention discloses a high-temperature environment catalyst electrochemical evaluation device. The device places the electrolytic cell of the electrochemical reaction unit within a jacketed reactor. External gas is introduced into the electrolytic cell to saturate the electrolyte. A set voltage is applied to the electrochemical reaction unit, and the working electrode and counter electrode undergo an electrochemical reaction in the saturated electrolyte. The performance and durability of the catalyst on the working electrode are evaluated. During the test, a constant-temperature circulating liquid exceeding 100°C is added to the jacket of the jacketed reactor through a constant-temperature liquid tank to maintain the electrolyte temperature in the electrolytic cell at the set temperature. Simultaneously, an air compressor maintains a high-pressure environment within the jacketed electrolytic cell, ensuring that the electrolyte does not evaporate at temperatures above 100°C. An independent reference electrode unit further enhances the stability of the collected data, meeting the catalyst evaluation requirements under conditions up to 150°C. This ensures the performance and durability of the catalyst in practical applications and solves the problem that existing evaluation devices cannot meet the catalyst evaluation requirements under conditions above 100°C. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the high-temperature environment catalyst electrochemical evaluation device of this utility model;

[0024] Figure 2 A schematic diagram of linear scanning voltammetry testing is provided for a specific embodiment of this utility model;

[0025] Wherein: 1-Electrochemical reaction unit; 11-Electrolytic cell; 12-Working electrode; 121-Rotating disk electrode; 122-Electrode shaft; 123-Electrode interface; 13-Counter electrode; 14-Ventilation pipeline; 2-High temperature and high pressure circulation unit; 21-Constant temperature liquid tank; 22-Jacketed reactor; 221-Liquid inlet; 222-Liquid outlet; 223-Gas inlet; 224-Gas outlet; 23-Circulating liquid pump; 24-Air compressor; 25-Sealing ring; 3-Independent reference electrode unit; 31-Reference electrode; 32-Independent electrolytic cell. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0028] With the development of proton exchange membrane fuel cells (PEMFCs), the maximum operating temperature of PEMFCs is gradually increasing from 80°C to 105°C and 120°C. Therefore, higher requirements are placed on existing catalyst electrochemical testing to meet catalyst evaluation needs that are closer to real-world application scenarios. This embodiment provides a method that more closely reflects application conditions than room temperature testing, offering a more accurate assessment of catalyst performance and durability under real-world operating conditions, thus obtaining more precise catalyst evaluation results to guide catalyst design and optimization.

[0029] The present invention will now be described in further detail with reference to the accompanying drawings:

[0030] Example 1

[0031] See Figure 1 As shown, this utility model discloses a high-temperature environment catalyst electrochemical evaluation device, including an electrochemical reaction unit 1, a high-temperature and high-pressure circulation unit 2, and an independent reference electrode unit 3. The electrochemical reaction unit 1 includes an electrolytic cell 11, a working electrode 12, and a counter electrode 13. The electrolytic cell 11 is filled with electrolyte and is also equipped with a venting pipe 14 to introduce external air into the electrolytic cell 11 to saturate the electrolyte. The working electrode 11 and the counter electrode 13, coated with the catalyst slurry to be tested, undergo an electrochemical reaction in the saturated electrolyte in the electrolytic cell 11. The high-temperature and high-pressure circulation unit 2 includes a constant-temperature liquid tank 21, a jacketed reactor 22, and an air compressor 24. The electrolytic cell 11 is disposed inside the jacketed reactor 22, and the air compressor 24 supplies air to the jacketed reactor 22. External gas is introduced to prevent the electrolyte in the electrolytic cell 11 from evaporating when operating at 150°C. The constant temperature liquid tank 21 can add constant temperature circulating liquid into the jacket of the jacketed reactor 11 to keep the electrolyte temperature in the electrolytic cell 11 constant. The independent reference electrode unit 3 includes an independent electrolytic cell 32 and a reference electrode 31. The independent reference electrode unit 3 is located outside the jacketed reactor 22 so that the data collected by the reference electrode is not affected by the high temperature and high pressure environment.

[0032] Example 2

[0033] This utility model discloses a high-temperature environment catalyst electrochemical evaluation device, including an electrochemical reaction unit 1, a high-temperature and high-pressure circulation unit 2, and an independent reference electrode unit 3. The electrochemical reaction unit 1 includes an electrolytic cell 11, a working electrode 12, and a counter electrode 13. The electrolytic cell 11 is filled with electrolyte and is also equipped with a venting pipe 14 to introduce external air into the electrolytic cell 11 to saturate the electrolyte. The working electrode 11 and the counter electrode 13, coated with the catalyst slurry to be tested, undergo an electrochemical reaction in the saturated electrolyte in the electrolytic cell 11. The high-temperature and high-pressure circulation unit 2 includes a constant-temperature liquid tank 21, a jacketed reactor 22, and an air compressor 24. The electrolytic cell 11 is disposed inside the jacketed reactor 22, and the air compressor 24 supplies air to the jacketed reactor 22. External gas is introduced to prevent the electrolyte in the electrolytic cell 11 from evaporating when operating at 150°C. The constant temperature liquid tank 21 can add constant temperature circulating liquid into the jacket of the jacketed reactor 11 to keep the electrolyte temperature in the electrolytic cell 11 constant. The independent reference electrode unit 3 includes an independent electrolytic cell 32 and a reference electrode 31. The independent reference electrode unit 3 is located outside the jacketed reactor 22 so that the data collected by the reference electrode is not affected by the high temperature and high pressure environment.

[0034] The high-temperature and high-pressure circulation unit 2 also includes a circulating liquid pump 23. The jacketed reactor 22 includes a liquid inlet 221 and a liquid outlet 222. The outlet of the constant temperature liquid tank 21 is connected to the inlet of the water inlet pipe. The circulating liquid pump 23 is installed in the water inlet pipe. The outlet of the water inlet pipe is connected to the liquid inlet 221. The liquid outlet 222 is connected to the inlet of the constant temperature liquid tank 21 through the outlet pipe.

[0035] Example 3

[0036] This utility model discloses a high-temperature environment catalyst electrochemical evaluation device, including an electrochemical reaction unit 1, a high-temperature and high-pressure circulation unit 2, and an independent reference electrode unit 3. The electrochemical reaction unit 1 includes an electrolytic cell 11, a working electrode 12, and a counter electrode 13. The electrolytic cell 11 is filled with electrolyte and is also equipped with a venting pipe 14 to introduce external air into the electrolytic cell 11 to saturate the electrolyte. The working electrode 11 and the counter electrode 13, coated with the catalyst slurry to be tested, undergo an electrochemical reaction in the saturated electrolyte in the electrolytic cell 11. The high-temperature and high-pressure circulation unit 2 includes a constant-temperature liquid tank 21, a jacketed reactor 22, and an air compressor 24. The electrolytic cell 11 is disposed inside the jacketed reactor 22, and the air compressor 24 supplies air to the jacketed reactor 22. External gas is introduced to prevent the electrolyte in the electrolytic cell 11 from evaporating when operating at 150°C. The constant temperature liquid tank 21 can add constant temperature circulating liquid into the jacket of the jacketed reactor 11 to keep the electrolyte temperature in the electrolytic cell 11 constant. The independent reference electrode unit 3 includes an independent electrolytic cell 32 and a reference electrode 31. The independent reference electrode unit 3 is located outside the jacketed reactor 22 so that the data collected by the reference electrode is not affected by the high temperature and high pressure environment.

[0037] The high-temperature and high-pressure circulation unit 2 also includes a circulating liquid pump 23. The jacketed reactor 22 includes a liquid inlet 221 and a liquid outlet 222. The outlet of the constant temperature liquid tank 21 is connected to the inlet of the water inlet pipe. The circulating liquid pump 23 is installed in the water inlet pipe. The outlet of the water inlet pipe is connected to the liquid inlet 221. The liquid outlet 222 is connected to the inlet of the constant temperature liquid tank 21 through the outlet pipe.

[0038] The jacketed reactor 22 also includes a gas inlet 223 and a gas outlet 224, wherein the gas inlet 223 is connected to the air compressor 24 through an air inlet pipe.

[0039] Example 4

[0040] This utility model discloses a high-temperature environment catalyst electrochemical evaluation device, including an electrochemical reaction unit 1, a high-temperature and high-pressure circulation unit 2, and an independent reference electrode unit 3. The electrochemical reaction unit 1 includes an electrolytic cell 11, a working electrode 12, and a counter electrode 13. The electrolytic cell 11 is filled with electrolyte and is also equipped with a venting pipe 14 to introduce external air into the electrolytic cell 11 to saturate the electrolyte. The working electrode 11 and the counter electrode 13, coated with the catalyst slurry to be tested, undergo an electrochemical reaction in the saturated electrolyte in the electrolytic cell 11. The high-temperature and high-pressure circulation unit 2 includes a constant-temperature liquid tank 21, a jacketed reactor 22, and an air compressor 24. The electrolytic cell 11 is disposed inside the jacketed reactor 22, and the air compressor 24 supplies air to the jacketed reactor 22. External gas is introduced to prevent the electrolyte in the electrolytic cell 11 from evaporating when operating at 150°C. The constant temperature liquid tank 21 can add constant temperature circulating liquid into the jacket of the jacketed reactor 11 to keep the electrolyte temperature in the electrolytic cell 11 constant. The independent reference electrode unit 3 includes an independent electrolytic cell 32 and a reference electrode 31. The independent reference electrode unit 3 is located outside the jacketed reactor 22 so that the data collected by the reference electrode is not affected by the high temperature and high pressure environment.

[0041] The high-temperature and high-pressure circulation unit 2 also includes a circulating liquid pump 23. The jacketed reactor 22 includes a liquid inlet 221 and a liquid outlet 222. The outlet of the constant temperature liquid tank 21 is connected to the inlet of the water inlet pipe. The circulating liquid pump 23 is installed in the water inlet pipe. The outlet of the water inlet pipe is connected to the liquid inlet 221. The liquid outlet 222 is connected to the inlet of the constant temperature liquid tank 21 through the outlet pipe.

[0042] The jacketed reactor 22 also includes a gas inlet 223 and a gas outlet 224, wherein the gas inlet 223 is connected to the air compressor 24 through an inlet pipe;

[0043] The top of the jacketed reactor 22 is provided with a sealing ring 25. The working electrode 12 and the counter electrode 13 both extend into the electrolytic cell 11 through the sealing ring 25, and the working electrode 12 and the counter electrode 13 are both sealed to the sealing ring 25.

[0044] Example 5

[0045] This utility model discloses a high-temperature environment catalyst electrochemical evaluation device, including an electrochemical reaction unit 1, a high-temperature and high-pressure circulation unit 2, and an independent reference electrode unit 3. The electrochemical reaction unit 1 includes an electrolytic cell 11, a working electrode 12, and a counter electrode 13. The electrolytic cell 11 is filled with electrolyte and is also equipped with a venting pipe 14 to introduce external air into the electrolytic cell 11 to saturate the electrolyte. The working electrode 11 and the counter electrode 13, coated with the catalyst slurry to be tested, undergo an electrochemical reaction in the saturated electrolyte in the electrolytic cell 11. The high-temperature and high-pressure circulation unit 2 includes a constant-temperature liquid tank 21, a jacketed reactor 22, and an air compressor 24. The electrolytic cell 11 is disposed inside the jacketed reactor 22, and the air compressor 24 supplies air to the jacketed reactor 22. External gas is introduced to prevent the electrolyte in the electrolytic cell 11 from evaporating when operating at 150°C. The constant temperature liquid tank 21 can add constant temperature circulating liquid into the jacket of the jacketed reactor 11 to keep the electrolyte temperature in the electrolytic cell 11 constant. The independent reference electrode unit 3 includes an independent electrolytic cell 32 and a reference electrode 31. The independent reference electrode unit 3 is located outside the jacketed reactor 22 so that the data collected by the reference electrode is not affected by the high temperature and high pressure environment.

[0046] The high-temperature and high-pressure circulation unit 2 also includes a circulating liquid pump 23. The jacketed reactor 22 includes a liquid inlet 221 and a liquid outlet 222. The outlet of the constant temperature liquid tank 21 is connected to the inlet of the water inlet pipe. The circulating liquid pump 23 is installed in the water inlet pipe. The outlet of the water inlet pipe is connected to the liquid inlet 221. The liquid outlet 222 is connected to the inlet of the constant temperature liquid tank 21 through the outlet pipe.

[0047] The jacketed reactor 22 also includes a gas inlet 223 and a gas outlet 224, wherein the gas inlet 223 is connected to the air compressor 24 through an inlet pipe;

[0048] The top of the jacketed reactor 22 is provided with a sealing ring 25. The working electrode 12 and the counter electrode 13 both extend into the electrolytic cell 11 through the sealing ring 25, and the working electrode 12 and the counter electrode 13 are both sealed to the sealing ring 25.

[0049] The working electrode 12 includes a rotating disk electrode 121, an electrode shaft 122, and an electrode interface 123. One end of the electrode shaft 122 is connected to the rotating disk electrode 121, and the other end is connected to the electrode interface 123. The counter electrode 13 is also connected to the electrode interface 123. The outer casing of the rotating disk electrode 121 is made of polyetheretherketone and does not contain tetrafluoroelastomer rings to ensure stability under high temperature and high pressure.

[0050] In the independent reference electrode unit 3, the reference electrode 31 is connected to the electrode interface 123 and is not located in the jacketed reactor 22, so as to increase the stability of data acquisition from the reference electrode 31.

[0051] When performing electrochemical tests on the catalyst using the aforementioned high-temperature environment catalyst electrochemical evaluation device, the following steps are included:

[0052] First, the catalyst slurry to be tested is coated onto the working electrode 12. Then, the working electrode 12 and the counter electrode 13 coated with the catalyst slurry to be tested are placed in an electrolytic cell 11 with saturated electrolyte. Then, the reference electrode 32 is placed in an independent electrolytic cell 31 to carry out an electrochemical reaction.

[0053] As an alternative to the evaluation device for electrocatalysts, the working electrode 12 includes a rotating disk electrode 121 coated with the catalyst to be tested, an electrode shaft 122, and an electrode interface 123. One end of the electrode shaft 122 is connected to the rotating disk electrode 121, and the other end is connected to the electrode interface 123.

[0054] The rotating disk electrode 121 is coated with the catalyst to be tested and the ionomer. The rotation drive method and working principle of the rotating disk electrode 121 are well-established and will not be elaborated here. By controlling the rotation speed of the rotating disk 121, the thickness of the electrolyte flow layer in the electrolytic cell 11 is changed, thereby controlling the mass transfer rate. High-speed rotation can eliminate concentration polarization caused by electrochemical reactions, thus effectively evaluating the activity of the catalyst. The rotating disk electrode 121 is made of polyetheretherketone and does not contain tetrafluoroethylene rings to ensure the stability of electrochemical testing under high temperature and high pressure.

[0055] During testing, the temperature of the constant-temperature liquid chamber 21 was set at 105~120℃, and the air pressure inside the jacketed reactor 22 was increased to above 2MPa using the air compressor 24. The electrolyte was an electrochemical test electrolyte such as H2SO4, HClO4, or H3PO4, with a concentration of 0.01~1mol / L. A catalyst slurry was prepared to a concentration of 0.1~5mg / mL and uniformly coated on the upper surface of the rotating disk electrode 121 with a loading of 10ug / cm³. 2 Up to 80ug / cm 2 The working electrode 12 is formed by connecting the electrode shaft 122 and the electrode interface 123; the counter electrode 13 is a platinum sheet or a graphite sheet; the reference electrode 32 is independent of the high temperature and high pressure cycling unit 2 and is used for stable data acquisition. The reference electrode 32 is a silver chloride electrode. The counter electrode 13 and the reference electrode 32 are thoroughly washed with deionized water and connected to the electrode interface 123 to complete the complete three-electrode electrochemical testing system.

[0056] Through the electrode interface 123 of the electrochemical reaction unit 1, the working electrode 12 is connected to the positive electrode of the electrochemical workstation, the counter electrode 13 is connected to the negative electrode of the electrochemical workstation, and the reference electrode 31 is connected to the reference electrode of the electrochemical workstation.

[0057] External gas is introduced into the electrolytic cell 12 of the jacketed reactor 22 through the vent pipe 14 of the electrochemical reaction unit 1, saturating the electrolyte in the electrolytic cell 11. By applying voltage to the electrochemical reaction unit 1, the working electrode 12 and the counter electrode 13 of the same unit undergo an electrochemical reaction in the electrolyte. The reference electrode 31 is located in an independent reference electrode unit 3 to provide a stable and known potential reference point, ensuring that the measured potential is accurate and repeatable. It is independent of the high temperature and high pressure environment for the accuracy of the reference potential. Therefore, the catalyst under test on the working electrode can be stably tested for performance and durability at an environment of 105℃~120℃, ensuring the activity and durability of the catalyst in actual application.

[0058] The high-temperature and high-pressure circulation unit 2 includes a circulating liquid pump 23, and the jacketed reactor 22 includes a liquid inlet 221 and a liquid outlet 222. The outlet of the constant temperature liquid tank 21 is connected to the inlet of the inlet pipe. The circulating liquid pump 23 is installed in the inlet pipe, and the outlet of the inlet pipe is connected to the liquid inlet 221. The liquid outlet 222 is connected to the inlet of the constant temperature liquid tank 21 through the outlet pipe. The circulating liquid pump 23 continuously circulates the constant temperature liquid in the constant temperature liquid tank 21 in the jacket of the jacketed reactor 22 to control the temperature in the electrolytic cell 11.

[0059] The circulating liquid pump 23 is a circulating peristaltic pump. When the pump body is operating, the roller will apply pressure to the elastic hose, forcing the liquid to move forward and forming a positive liquid flow. The circulating liquid pump 23 provides sufficient kinetic energy for the liquid circulation in the jacketed reactor 22, which is beneficial to the liquid circulation in the jacketed reactor 22 and to achieve temperature uniformity.

[0060] Because the electrolyte is prone to evaporation under high-temperature testing conditions, its volume and concentration change, affecting the test results.

[0061] The jacketed reactor 22 includes a gas inlet 223 and a gas outlet 224. The gas inlet 223 is connected to the air compressor 25 through an air inlet pipe. By increasing the pressure inside the electrolytic cell 11 to above 2MPa, the electrolyte does not evaporate when the temperature reaches 120℃, thus ensuring a stable liquid level in the electrolytic cell 11 during electrochemical testing of the catalyst. This reduces the significant impact of electrolyte concentration caused by rapid evaporation during testing, thereby greatly improving the stability of catalyst performance and durability testing above 100℃.

[0062] The jacketed reactor 22 also includes a sealing ring 25. The working electrode 12, the counter electrode 13, and the ventilation pipe 14 pass through the sealing ring 25 to reach the electrolytic cell 11 inside the jacketed reactor 22. Compared with the open electrochemical workstation, this high-temperature environment catalyst electrochemical evaluation device ensures that when the air compressor 24 pressurizes the jacketed reactor 22, the sealing ring 25 can keep the air pressure inside the jacketed reactor 22 above 2MPa, so that the electrolyte in the electrolytic cell 11 does not evaporate at 100°C, ensuring stability during high-temperature electrochemical testing with three electrodes.

[0063] The high-temperature environment catalyst electrochemical evaluation device provided by this utility model is suitable for catalyst testing under high-temperature conditions exceeding 100℃, realizing high-temperature performance and durability testing of catalysts above 100℃. First, all components in the jacketed reactor 22 are thoroughly washed, electrolyte and jacketed temperature-controlled circulating liquid at the set temperature are added, the working electrode 12 and counter electrode 13 are placed in the electrolytic cell 11, and the reference electrode 31 is located in an independent reference electrode unit 3. The working electrode 12, counter electrode 13 and reference electrode 31 are connected to the electrode interface 123. The air pressure in the cavity of the jacketed reactor 22 is increased to 2MPa by the air compressor 15, so that the liquid level of the electrolyte is stable when it exceeds 100℃. The vent pipe 14 is opened to saturate the electrolyte gas in the electrolytic cell 11. The circulating water pump 23 is turned on to stabilize the electrolyte ambient temperature, so that the catalyst testing temperature can reach the range of 105℃ to 120℃. Thus, the debugging of the high-temperature electrochemical catalyst testing device is completed, and the performance and durability of the catalyst can be tested.

[0064] like Figure 2 As shown, linear cyclic voltammetry was used to evaluate the catalyst's activity in the oxygen reduction reaction during catalyst performance testing. The rotation speed was typically set between 400 and 2500 RPM to control the thickness of the oxygen diffusion layer on the electrode surface, which affects mass transfer. The voltammetric scan range was set from 1V to -0.2V (vs. RHE). At the start of the test, the potential was gradually decreased at a scan rate of 5 mV / s, and the relationship between current density and potential was recorded. By recording the half-wave potential, the catalytic performance of the catalyst at different test temperatures could be compared; a higher half-wave potential indicates better catalytic activity.

[0065] To address the increasingly high-temperature operating conditions of future proton exchange membrane fuel cells, this invention proposes a more suitable and stable electrochemical testing device for catalyst performance and accelerated aging above 100°C. By employing isothermal cycling and internal pressurization, a catalyst performance and durability evaluation device was designed for temperatures above 100°C and with limited electrolyte evaporation. The stability of the testing system is improved through an independent reference electrode unit and a maximally sealed structure design. Furthermore, a visualization window allows for real-time monitoring of the electrolyte level and pressure adjustment, minimizing interference with the catalyst electrochemical testing. This high-temperature catalyst electrochemical evaluation device more closely approximates the future operating conditions of high-temperature proton exchange membrane fuel cells, and has significant implications for evaluating catalyst performance and durability.

[0066] The above content is only for illustrating the technical concept of this utility model and should not be construed as limiting the scope of protection of this utility model. Any modifications made to the technical solution based on the technical concept proposed in this utility model shall fall within the scope of protection of the claims of this utility model.

Claims

1. A high-temperature environment catalyst electrochemical evaluation device, characterized in that, include: An electrochemical reaction unit (1) is provided, comprising an electrolytic cell (11), a working electrode (12), and a counter electrode (13); one end of the working electrode (12) and the counter electrode (13) is inserted into the electrolyte in the electrolytic cell (11); a venting pipe (14) is also inserted into the electrolyte in the electrolytic cell (11). The high-temperature and high-pressure circulation unit (2) includes a constant-temperature liquid tank (21), a jacketed reactor (22), and an air compressor (24); the electrolytic cell (11) is located inside the jacketed reactor (22) and a gap is left between it and the inner side wall of the jacketed reactor (22); the constant-temperature liquid tank (21) and the air compressor (24) are both located outside the jacketed reactor (22) and are connected to the gap inside the jacketed reactor (22) through pipelines; Independent reference electrode unit (3), which is used to ensure stable data acquisition, is set outside the jacketed reactor (22).

2. The high-temperature environment catalyst electrochemical evaluation device according to claim 1, characterized in that, The working electrode (12) includes a rotating disk electrode (121), an electrode shaft (122), and an electrode interface (123); one end of the electrode shaft (122) is inserted into the electrolyte in the electrolytic cell (11), and the other end is connected to the electrode interface (123); the rotating disk electrode (121) is disposed on one end of the electrode shaft (122); One end of the counter electrode (13) is inserted into the electrolyte in the electrolytic cell (11), and the other end is connected to the electrode interface (123).

3. The high-temperature environment catalyst electrochemical evaluation device according to claim 2, characterized in that, The independent reference electrode unit (3) includes an independent electrolytic cell (32) and a reference electrode (31); the independent electrolytic cell (32) is located outside the jacketed reactor (22), one end of the reference electrode (31) is inserted into the electrolyte in the independent electrolytic cell (32), and the other end is connected to the electrode interface (123).

4. The high-temperature environment catalyst electrochemical evaluation device according to claim 1, characterized in that, The high-temperature and high-pressure circulation unit (2) also includes a circulating liquid pump (23); the jacketed reactor (22) is provided with a liquid inlet (221) and a liquid outlet (222) on both sides; the outlet of the constant temperature liquid tank (21) is connected to the inlet of the circulating liquid pump (23) through a pipeline, and the outlet of the circulating liquid pump (23) is connected to the liquid inlet (221) through a pipeline; the liquid outlet (222) is connected to the inlet of the constant temperature liquid tank (21) through a pipeline.

5. The high-temperature environment catalyst electrochemical evaluation device according to claim 4, characterized in that, The jacketed reactor (22) is also provided with a gas inlet (223) and a gas outlet (224); the gas inlet (223) is connected to the air compressor (24) through an air inlet pipe.

6. The high-temperature environment catalyst electrochemical evaluation device according to claim 5, characterized in that, The gas inlet (223) and gas outlet (224) are at a higher height on the jacketed reactor (22) than the liquid inlet (221) and liquid outlet (222).

7. The high-temperature environment catalyst electrochemical evaluation device according to claim 5, characterized in that, The liquid outlet (222) is located at the top of the jacketed reactor (22).

8. The high-temperature environment catalyst electrochemical evaluation device according to claim 5, characterized in that, The top of the jacketed reactor (22) is provided with a sealing ring (25); one end of the working electrode (12) and the counter electrode (13) are inserted into the electrolyte in the electrolytic cell (11) through the sealing ring (25); and the working electrode (12) and the counter electrode (13) are sealed and connected to the sealing ring (25).

9. The high-temperature environment catalyst electrochemical evaluation device according to claim 5, characterized in that, The circulating liquid pump (23) is a circulating peristaltic pump.

10. The high-temperature environment catalyst electrochemical evaluation device according to claim 1, characterized in that, The gas pressure inside the jacketed reactor (22) is above 2 MPa.

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