A method and device for online detection of hydrogen evolution / oxygen evolution reaction catalyst activity

Abstract

The invention discloses an online detection method and device for the activity of a hydrogen evolution / oxygen evolution reaction catalyst, and characterizes the activity of the hydrogen evolution / oxygen evolution reaction catalyst by the starting potential on the surface of the hydrogen evolution / oxygen evolution catalytic electrode; the online detection method for the starting potential on the electrode surface comprises the following steps: using a prism-type total reflection system with incident parallel light to perform real-time imaging on the surface of the hydrogen evolution / oxygen evolution catalytic electrode; simultaneously using a potential scanning device module to perform potential scanning on the hydrogen evolution / oxygen evolution catalytic electrode and perform vacuum treatment; according to the change of light intensity at different positions in the image with the potential, the starting potential at different positions on the surface of the hydrogen evolution / oxygen evolution catalytic electrode is obtained; the hydrogen evolution / oxygen evolution catalytic electrode comprises an electrode substrate, and a plurality of channels are provided on the electrode substrate, and exhaust flow channels are provided between the channels. The invention allows the activity of multiple catalyst samples to be detected at one time, greatly increases the number of detections of a single catalyst sample, and eliminates the system error caused by different detection batches.

Description

Technical Field

[0001] The invention belongs to the technical field of imaging measurement, and in particular relates to an online detection method and device for the activity of a hydrogen evolution / oxygen evolution reaction catalyst. Background Art

[0002] With the intensification of environmental pollution and energy crisis, renewable clean energy such as hydrogen has become the new generation of energy with the greatest development potential. At present, the main methods for preparing hydrogen are fossil fuel hydrogen production and industrial byproduct hydrogen production. On the one hand, the purity of hydrogen produced by these two methods is not high, and on the other hand, they do not help reduce dependence on fossil fuels and environmental pollution. New carbon-free hydrogen production methods such as water electrolysis, water photolysis and biomass hydrogen production are very popular.

[0003] Due to the high energy barrier caused by the reaction, the process of hydrogen evolution reaction (HER) is slow, and it is necessary to add efficient, stable and economical HER catalysts, such as Pt, MoS2, etc. There are many types of catalysts, and the catalytic activity of different catalysts is different. The loading amount of the catalyst also plays a vital role in the catalytic effect. Too little loading will result in low catalytic activity, and too much loading will cause problems such as catalyst shedding and uneven distribution.

[0004] Traditional methods for characterizing catalytic electrodes include SEM, TEM, XRD, and X-ray spectroscopy. Electrochemical characterization methods for electrode activity mainly include potential scanning method (linear scanning voltammetry, cyclic voltammetry), constant current charge-discharge method, and electrochemical impedance spectroscopy. Such methods can only give the overall reaction activity of the electrode. For example, cyclic voltammetry can only collect the average current density change of the electrode after voltage is applied, that is, it is impossible to characterize the difference in activity at different positions of the modified electrode. The above detection methods have extremely low detection efficiency and can only detect one sample at a time. To study the effects of catalyst type, loading amount, and loading method, multiple experiments need to be designed, which greatly increases the number of experiments. In addition, due to electrode passivation and other reasons, it is impossible to ensure that the experimental conditions are consistent each time. Summary of the invention

[0005] In order to solve the technical problems raised in the above background technology, the purpose of the present invention is to provide an online detection method and device for the activity of hydrogen evolution / oxygen evolution reaction catalysts. The present invention allows the activity of multiple hydrogen evolution / oxygen evolution reaction catalyst samples to be detected at one time, greatly increasing the number of catalyst samples detected at a time. Compared with the traditional method of only measuring the activity of one sample at a time, the detection efficiency is greatly improved, and the system error caused by different detection batches is eliminated, which has the advantages of high detection efficiency and good consistency.

[0006] In order to achieve the above-mentioned object, the technical scheme adopted by the present invention is as follows: on the one hand, the present invention provides an online detection method for the activity of a hydrogen evolution / oxygen evolution reaction catalyst, which characterizes the activity of the hydrogen evolution / oxygen evolution reaction catalyst by the surface starting potential of the hydrogen evolution / oxygen evolution catalytic electrode;

[0007] The online detection method of the surface onset potential of the hydrogen / oxygen evolution catalytic electrode comprises the following steps:

[0008] (1) using a prism-type total reflection system with parallel light incident to perform real-time imaging on the surface of the hydrogen evolution / oxygen evolution catalytic electrode; while the prism-type total reflection system with parallel light incident to perform real-time imaging on the surface of the hydrogen evolution / oxygen evolution catalytic electrode, a potential scanning device module is used to perform potential scanning on the hydrogen evolution / oxygen evolution catalytic electrode and perform vacuum treatment to promptly discharge generated bubbles;

[0009] (2) obtaining the starting potential at different positions on the surface of the hydrogen / oxygen evolution catalytic electrode according to the change of light intensity (potential) at different positions in the image over time, wherein the starting potential is the potential when the light intensity just starts to change;

[0010] The hydrogen / oxygen evolution catalytic electrode comprises an electrode substrate, a plurality of channels are arranged on the electrode substrate, and exhaust flow channels are arranged between the channels.

[0011] Furthermore, the online detection method of the surface onset potential of the hydrogen evolution / oxygen evolution catalytic electrode specifically comprises the following steps:

[0012] (1) The prism-type total reflection system with parallel light incident is adjusted to a state where the surface of the hydrogen evolution / oxygen evolution catalytic electrode can be clearly imaged, ensuring that the channels used are within the imaging range;

[0013] (2) using a potential scanning device module to perform potential scanning on the hydrogen evolution / oxygen evolution catalytic electrode and simultaneously perform vacuum treatment;

[0014] (3) using a prism-type total reflection system with parallel light incidence to collect and save the real-time changes of the two-dimensional image of the hydrogen evolution / oxygen evolution catalytic electrode during the potential scanning process;

[0015] (4) The curve of the change of light intensity over time (potential) at different positions of the image is plotted by using the collected two-dimensional image group to obtain the starting potential at different positions on the surface of the hydrogen evolution / oxygen evolution catalytic electrode, wherein the starting potential is the potential when the light intensity just starts to change.

[0016] Furthermore, the parallel light incident prism type total reflection system comprises an incident parallel light module, a TIR module, and an imaging detection module which are arranged in sequence.

[0017] Further, the incident parallel light module is used to provide parallel incident light;

[0018] The TIR module changes the refractive index by total reflection of parallel incident light at the contact surface between the TIR module and the hydrogen / oxygen evolution catalytic electrode, thereby changing the magnitude of the total reflection light intensity;

[0019] The imaging detection module is used, on the one hand, to collect reflected light imaging on the surface of the hydrogen evolution / oxygen evolution catalytic electrode to obtain position information, and on the other hand, to detect light intensity changes in real time, and then obtain the refractive index changes of the electrolyte near each channel of the hydrogen evolution / oxygen evolution catalytic electrode based on the relationship between light intensity and refractive index, and then obtain the starting potential when the refractive index changes at the channel on the surface of the hydrogen evolution / oxygen evolution catalytic electrode.

[0020] Furthermore, the potential scanning device module promotes the hydrogen evolution / oxygen evolution reaction to generate bubbles through potential scanning, thereby driving the refractive index of the surface of the hydrogen evolution / oxygen evolution catalytic electrode to change.

[0021] On the other hand, the present invention provides an online detection device for the activity of a hydrogen evolution / oxygen evolution reaction catalyst, comprising a hydrogen evolution / oxygen evolution catalytic electrode, a prism-type total reflection system for incident parallel light, and a potential scanning device module;

[0022] The hydrogen / oxygen evolution catalytic electrode comprises an electrode substrate, a plurality of channels are arranged on the electrode substrate, and exhaust flow channels are arranged between the channels;

[0023] The parallel light incident prism type total reflection system comprises an incident parallel light module, a TIR module, and an imaging detection module arranged in sequence;

[0024] The incident parallel light module is used to provide parallel incident light;

[0025] The TIR module changes the refractive index by total reflection of parallel incident light at the contact surface between the TIR module and the hydrogen / oxygen evolution catalytic electrode, thereby changing the magnitude of the total reflection light intensity;

[0026] The imaging detection module is used to collect reflected light imaging of the surface of the hydrogen evolution / oxygen evolution catalytic electrode to obtain position information, and is used to detect light intensity changes in real time, and then obtain the refractive index changes of the electrolyte near each channel of the hydrogen evolution / oxygen evolution catalytic electrode according to the relationship between light intensity and refractive index, and then obtain the starting potential when the refractive index changes at the channel on the surface of the hydrogen evolution / oxygen evolution catalytic electrode, and characterize the activity of the hydrogen evolution / oxygen evolution reaction catalyst through the starting potential;

[0027] The potential scanning device module performs potential scanning on the hydrogen / oxygen evolution catalytic electrode to promote the hydrogen / oxygen evolution reaction to generate bubbles, so that the refractive index of the electrolyte at the hydrogen / oxygen evolution catalytic electrode changes, thereby changing the intensity of the TIR reflected light.

[0028] Furthermore, the incident parallel light module includes a point light source and a collimating lens which are arranged in sequence;

[0029] Preferably, the TIR module includes a prism, and the prism is parallel to the hydrogen evolution / oxygen evolution catalytic electrode and is separated by a certain distance; the distance between the prism and the hydrogen evolution / oxygen evolution catalytic electrode is maintained in the range of several micrometers to several hundred micrometers, and the specific distance is related to the diffusion coefficient of the bubbles and the electrolyte;

[0030] Preferably, the imaging detection module comprises an imaging lens group and a camera which are arranged in sequence; more preferably, the imaging detection module further comprises a filter, and the filter is located between the TIR module and the imaging lens group.

[0031] Furthermore, the potential scanning device module performs potential scanning on the hydrogen / oxygen evolution catalytic electrode through an electrochemical workstation to promote the hydrogen / oxygen evolution reaction to generate bubbles to produce a change in the refractive index of the hydrogen / oxygen evolution catalytic electrode surface.

[0032] Furthermore, it also includes a vacuum sealing device, in which the TIR module and the hydrogen / oxygen evolution catalytic electrode are located, and the vacuum sealing device allows bubbles generated by the hydrogen / oxygen evolution reaction to be discharged along the exhaust flow channel.

[0033] Furthermore, the vacuum sealing device comprises a sealing cover, a vacuum device, a window for incident light and a window for outgoing light.

[0034] Since a large number of bubbles will be generated on the surface of the prism and the hydrogen / oxygen evolution catalytic electrode during the hydrogen / oxygen evolution process, the refractive index of the electrolyte will change greatly, for example, the refractive index from the liquid phase to the gas phase drops from about 1.338 to about 1, and the refractive index detection range of the TIR refractive index measurement technology is about 0.001 to 0.01, and it is impossible to measure the refractive index change from the water phase to the gas phase, and it is difficult to perform online detection of hydrogen / oxygen evolution to obtain the reaction activity of different positions of the hydrogen / oxygen evolution catalytic electrode. However, the applicant has found that before a large number of macroscopic bubbles are generated, there will be a process of generating microbubbles, during which the refractive index of the prism surface will undergo a slight change, which can be measured by the TIR technology in this process, and the corresponding potential at this time is the starting potential.

[0035] The beneficial effects of the present invention are: the present invention can realize online in-situ detection of a large number of electrodes treated with different catalysts at the same time, thereby realizing a large number of screening of loading conditions such as catalyst composition, type, structure and loading mode, greatly reducing the number of experiments, saving labor costs and test costs. The present invention obtains the electrochemical reaction activity of electrodes (electrodes treated with different catalysts) in each channel while ensuring that the experimental conditions of each channel are consistent, eliminates sample measurement errors caused by different batches of experiments, and ensures comparability between different channels. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic structural diagram of a hydrogen / oxygen evolution catalytic electrode according to an embodiment of the present invention;

[0037] Figure 2 It is a module diagram of an online detection device for the activity of a hydrogen evolution / oxygen evolution reaction catalyst in an embodiment of the present invention;

[0038] Figure 3 Schematic diagram of the structure of an online detection device for the activity of a hydrogen evolution / oxygen evolution reaction catalyst in an embodiment of the present invention;

[0039] Figure 4 a is a schematic diagram of the structure of the hydrogen / oxygen evolution catalytic electrode prepared by using a 1 cm side graphite plate as the electrode substrate, a flux of 5×5, and a loaded Pt / C catalyst. Figure 4 b is the relationship curve between light intensity and potential corresponding to five different concentrations of Pt / C catalysts A to E;

[0040] Figure 5 a is a schematic diagram of the experiment when the graphite plate and the prism are not parallel. Figure 5 b is the relationship between the reflected light intensity and the potential corresponding to the five points A to E;

[0041] Among them, 1. incident parallel light module, 11. point light source, 12. collimating lens, 2. TIR module, 21. prism, 3. imaging detection module, 31. filter, 32. imaging lens group, 33. camera, 34. electrode imaging schematic diagram, 4. potential scanning device module, 41. electrochemical workstation, 42. electrolytic cell, 5. hydrogen evolution / oxygen evolution catalytic electrode, 51. electrode substrate, 52. channel, 53. exhaust flow channel, 6. vacuum sealing device, 61. sealing cover, 62. vacuum device, 63. incident light window, 64. outgoing light window. DETAILED DESCRIPTION

[0042] The method for characterizing the hydrogen / oxygen evolution catalytic electrode in the embodiment of the present invention is based on a three-electrode system combined with a traditional electrical method (linear sweep voltammetry LSV) and TIR technology for imaging and real-time detection, so as to realize the measurement of the activity of each channel of the hydrogen / oxygen evolution catalytic electrode. With the increase of the LSV potential, the surface current of the hydrogen / oxygen evolution catalytic electrode is first stabilized for a period of time, and the current increases rapidly after crossing the starting potential, accompanied by the electrochemical reaction on the surface of the hydrogen / oxygen evolution catalytic electrode to generate a large number of bubbles, and the area near the hydrogen / oxygen evolution catalytic electrode changes from liquid phase to gas phase, and the refractive index is greatly reduced, and the reflected light intensity will also change accordingly, so as to be distinguished by the receiving device, that is, the electrochemical activity size of each channel of the hydrogen / oxygen evolution catalytic electrode can be judged according to the change of the reflected light intensity of the electrolyte near each channel of the hydrogen / oxygen evolution catalytic electrode (i.e., the size of the hydrogen / oxygen evolution starting potential, the smaller the absolute value of the starting potential, the better the activity). The hydrogen / oxygen evolution catalytic electrode prepared under different catalyst loading conditions is characterized by the starting potential distribution using total reflection imaging technology, which realizes a large number of screening of electrode materials under conditions such as different catalyst components, types, structures and loading methods.

[0043] The embodiment of the present invention includes the preparation of hydrogen evolution / oxygen evolution catalytic electrodes and the real-time detection of the refractive index of the electrolyte near the contact point between the prism and the electrode by a total reflection imaging system. The present invention can obtain the average starting potential of the electrode surface of each channel during the potential scanning process by comprehensively comparing the refractive index changes of the solution near the hydrogen evolution / oxygen evolution catalytic electrodes of each channel according to the relationship between the refractive index and the generation of microbubbles, thereby providing a detection tool for comparing the electrochemical performance of composite electrode materials prepared by different catalyst components, types, structures and loading methods.

[0044] The present invention is further described below in conjunction with the accompanying drawings and a preferred specific implementation manner.

[0045] Before the detection, the present application needs to prepare a hydrogen evolution / oxygen evolution catalytic electrode 5 for the hydrogen evolution / oxygen evolution reaction during the potential scanning process. The structural schematic diagram of the hydrogen evolution / oxygen evolution catalytic electrode 5 is as follows: Figure 1 As shown, it includes an electrode substrate 51, and a plurality of channels 52 are provided on the electrode substrate 51. An exhaust flow channel 53 is provided between the channels 52. The exhaust flow channel 53 is designed between each channel 52 to be used for vacuuming and removing generated bubbles during detection, so as to ensure that the bubbles generated in each channel 52 will not interfere with each other during detection. During the detection process, a vacuuming treatment needs to be performed through a vacuuming sealing device 6 to ensure that the generated bubbles can be discharged in time. The structural schematic diagram of the vacuuming sealing device 6 is shown in FIG. Figure 3As shown, the vacuum sealing device includes a sealing cover 61, a vacuum device 62, an incident light window 63 and an outgoing light window 64. The settings of the incident light window 63 and the outgoing light window 64 ensure that the incident light path and the outgoing light path are not affected; the TIR module 2, the hydrogen / oxygen evolution catalytic electrode 5, and the electrolytic cell 42 are located in the vacuum sealing device 6. In addition, after the bubbles are removed, the next test can be carried out without removing the sample, thereby realizing multiple measurements of the hydrogen / oxygen evolution catalytic electrode 5.

[0046] The module diagram of the online detection device for the activity of the hydrogen evolution / oxygen evolution reaction catalyst used in the embodiment of the present application is as follows: Figure 2 As shown, it includes an incident parallel light module 1, a TIR module 2, an imaging detection module 3, and a potential scanning device module 4. The incident parallel light module 1 generates parallel incident light. The TIR module 2 changes the refractive index by total reflection of the parallel incident light on the contact surface of the TIR module 2 and the hydrogen evolution / oxygen evolution catalytic electrode 5, and then changes the magnitude of the total reflection light intensity, thereby realizing the synchronous detection of the reaction activity of the hydrogen evolution / oxygen evolution catalytic electrode 5 in each channel. The imaging detection module 3 collects the reflected light imaging on the surface of the hydrogen evolution / oxygen evolution catalytic electrode 5 on the one hand to obtain the position information, and on the other hand, detects the light intensity change in real time, and then obtains the refractive index change of the electrolyte near each channel 52 of the hydrogen evolution / oxygen evolution catalytic electrode 5 according to the relationship between the light intensity and the refractive index, and then obtains the starting potential of each channel 52 of the hydrogen evolution / oxygen evolution catalytic electrode 5. The potential scanning device module 4 performs a potential scanning on the hydrogen evolution / oxygen evolution catalytic electrode 5, on the one hand, to obtain the overall voltage and current density change curve of the hydrogen evolution / oxygen evolution catalytic electrode 5, and on the other hand, through the potential scanning, the hydrogen evolution / oxygen evolution reaction is prompted to generate bubbles to produce a change in the surface refractive index of the hydrogen evolution / oxygen evolution catalytic electrode 5, thereby causing the TIR reflected light intensity to change.

[0047] The structural schematic diagram of the online detection device for the activity of the hydrogen evolution / oxygen evolution reaction catalyst is as follows: Figure 3As shown, the incident parallel light module 1 includes a point light source 11 and a collimating lens 12 arranged in sequence, and obtains parallel incident light, and is incident on the TIR module 2 at an angle close to the total reflection angle (i.e., the angle corresponding to the highest sensitivity of the light intensity type TIR); the TIR module 2 includes a prism 21 with a refractive index of 1.75, and the prism 21 is parallel to the hydrogen evolution / oxygen evolution catalytic electrode 5, and a gap of several microns to several hundred microns is maintained. The parallel incident light directly hits the surface of the prism 21 to cause total reflection, and is reflected on the surface of the hydrogen evolution / oxygen evolution catalytic electrode 5. There are bubbles generated; the imaging detection module 3 includes a filter 31, an imaging lens group 32 and a camera 33 arranged in sequence. In order to maintain the monochromaticity of the light, no interference fringes appear and the accuracy is higher, the interface reflected light needs to pass through the narrow-band filter 31, and then pass through the imaging lens group 32 before being received by the camera 33; since the distance between the hydrogen evolution / oxygen evolution catalytic electrode 5 and the prism 21 is small, the parallel light can be imaged on the surface of the hydrogen evolution / oxygen evolution catalytic electrode 5 after being reflected through the imaging lens group 32 and received by the camera 33. The schematic diagram of electrode imaging is shown in FIG. Figure 3 As shown in 34. A three-electrode system is adopted, the electrolytic cell 42 includes an electrolyte and a hydrogen evolution / oxygen evolution catalytic electrode 5, and the potential scanning device module 4 performs potential scanning on the working electrode (hydrogen evolution / oxygen evolution catalytic electrode 5) through the electrochemical workstation 41 to promote the hydrogen evolution / oxygen evolution reaction to generate bubbles; the potential scanning device module 4 performs potential scanning on the hydrogen evolution / oxygen evolution catalytic electrode 5 to change the refractive index of the electrolyte (0.5MH2SO4 solution) at the hydrogen evolution / oxygen evolution catalytic electrode 5, which causes the TIR reflected light intensity to change and also causes the two-dimensional imaging image to evolve, and then the electrochemical performance of the hydrogen evolution / oxygen evolution catalytic electrode 5 prepared by different catalyst types, compositions, structures and loading methods is quickly screened by the optical TIR method.

[0048] An online detection method for the activity of a hydrogen evolution / oxygen evolution reaction catalyst using an online detection device for the activity of a hydrogen evolution / oxygen evolution reaction catalyst comprises the following steps:

[0049] (1) preparing hydrogen / oxygen evolution catalytic electrodes 5 loaded with different components, types, structures and different loading methods;

[0050] (2) The prism-type total reflection system with parallel light incident thereon is adjusted to a state where the surface of the hydrogen evolution / oxygen evolution catalytic electrode 5 can be clearly imaged, and the channels 52 used are ensured to be within the imaging range;

[0051] (2) using a potential scanning device module 4 to perform potential scanning on the hydrogen evolution / oxygen evolution catalytic electrode 5, and simultaneously performing a vacuum treatment;

[0052] (3) using a prism-type total reflection system with parallel light incident to collect and save the real-time changes of the two-dimensional image of the hydrogen evolution / oxygen evolution catalytic electrode 5 during the potential scanning process;

[0053] (4) The light intensity at different positions of the image is plotted against time (potential) by using the collected two-dimensional image group to obtain the starting potential at different positions on the surface of the hydrogen evolution / oxygen evolution catalytic electrode, and then the activity of different hydrogen evolution / oxygen evolution reaction catalysts is obtained. The starting potential is the potential when the light intensity just starts to change.

[0054] A graphite plate with a side length of 1 cm was used as the electrode substrate, and the flux was 5×5. Taking the loading of Pt / C catalyst as an example, Pt / C powder was dispersed in a mixed solution of ethanol, water, and Nafion, and five Pt / C solutions with different concentrations were prepared and loaded into the five horizontal channels on the graphite plate in sequence, such as Figure 4 As shown in a, the concentration of Pt / C catalyst increases from A to E, and each group of Pt / C catalyst concentrations is repeated five times to eliminate the influence of random errors. A flow channel is designed between each channel to allow vacuum to remove the generated bubbles during the side test, ensuring that the bubbles generated in each channel will not interfere with each other during the test. The obtained light intensity and potential relationship curve is shown in Figure 4 As shown in b, as shown in the figure, the catalyst concentration increases from A to E, the starting potential decreases, and the activity becomes better.

[0055] During the measurement process, keep the graphite plate and the prism non-parallel, and take five points A, B, C, D, and E at different distances to perform total reflection tests respectively, such as Figure 5 As shown in a, Figure 5b is the relationship between the reflected light intensity and potential corresponding to the five points A to E. It can be seen from the figure that the starting potential of the closest point A is closer to 0V, while the starting potential of the farthest point E is farther away from 0V, indicating that the greater the distance between the prism and the electrode, the more serious the hysteresis of the starting potential. In our experiment, we found that the distance between the hydrogen evolution / oxygen evolution catalytic electrode and the prism surface will affect the starting potential measured by TIR. When the distance between the hydrogen evolution / oxygen evolution catalytic electrode and the prism is small or even tightly fitted, the starting potential obtained by the total reflection optical signal after further processing is closer to the actual starting potential of the point, but the generated bubbles cannot be discharged in time and diffuse to the surface of other channel electrode materials, thereby affecting the measurement of the electrochemical properties of other channel electrode materials; when the distance between the composite electrode material and the prism is large, the starting potential obtained after the calculation of the measured optical signal will lag behind the actual value, resulting in the measurement error of the electrochemical activity. Therefore, in the actual high-throughput composite electrode material electrochemical activity online measurement process, the hydrogen evolution / oxygen evolution catalytic electrode should be parallel to the prism surface and the distance should be moderate to eliminate the error caused by the hysteresis phenomenon. When the absolute value of the potential is greater than the starting potential of a channel, a large number of bubbles will be generated in the channel. If they are not discharged in time, the bubbles will drift to other channels, causing measurement errors. Therefore, exhaust channels are designed between different channels on the high-throughput electrode material, and the bubbles are extracted through the channels by vacuuming during the measurement process to avoid the accumulation of bubbles and facilitate subsequent measurements.

[0056] The above description is only a specific implementation mode of the present invention, not all implementation modes. Any equivalent changes made to the technical solution of the present invention by ordinary technicians in this field after reading the specification of the present invention are covered by the claims of the present invention.

Claims

1. An online detection method for the activity of a hydrogen evolution / oxygen evolution reaction catalyst, characterized in that: The activity of hydrogen evolution / oxygen evolution reaction catalyst is characterized by the surface starting potential of hydrogen evolution / oxygen evolution catalytic electrode; The online detection method of the surface onset potential of the hydrogen / oxygen evolution catalytic electrode comprises the following steps: (1) using a prism-type total reflection system with parallel light incident on the surface of the hydrogen evolution / oxygen evolution catalytic electrode to perform real-time imaging; while the prism-type total reflection system with parallel light incident on the surface of the hydrogen evolution / oxygen evolution catalytic electrode performs real-time imaging, a potential scanning device module is used to perform potential scanning on the hydrogen evolution / oxygen evolution catalytic electrode and perform vacuum treatment; (2) obtaining the starting potential at different positions on the surface of the hydrogen evolution / oxygen evolution catalytic electrode according to the change of light intensity at different positions in the image with electric potential, wherein the starting potential is the potential when the light intensity just starts to change; The hydrogen / oxygen evolution catalytic electrode comprises an electrode substrate, a plurality of channels are arranged on the electrode substrate, and exhaust flow channels are arranged between the channels.

2. The online detection method for hydrogen evolution / oxygen evolution reaction catalyst activity according to claim 1, characterized in that: The online detection method of the surface onset potential of the hydrogen evolution / oxygen evolution catalytic electrode specifically comprises the following steps: (1) Adjust the prism-type total reflection system with parallel light incident to a state where the surface of the hydrogen evolution / oxygen evolution catalytic electrode can be clearly imaged, ensuring that all channels used are within the imaging range; (2) using a potential scanning device module to perform potential scanning on the hydrogen evolution / oxygen evolution catalytic electrode and simultaneously perform vacuum treatment; (3) A prism-type total reflection system with parallel light incidence is used to collect and save the real-time changes of the two-dimensional image of the hydrogen evolution / oxygen evolution catalytic electrode during the potential scanning process; (4) A curve of light intensity versus electric potential at different positions of the image is plotted using the collected two-dimensional image group to obtain the starting potential at different positions on the surface of the hydrogen evolution / oxygen evolution catalytic electrode, where the starting potential is the potential when the light intensity just starts to change.

3. The online detection method for the activity of hydrogen evolution / oxygen evolution reaction catalyst according to claim 1 or 2, characterized in that: The parallel light incident prism type total reflection system comprises an incident parallel light module, a TIR module and an imaging detection module which are arranged in sequence; the TIR module comprises a prism which is parallel to the hydrogen / oxygen evolution catalytic electrode and is spaced from several micrometers to several hundred micrometers apart.

4. The online detection method for hydrogen evolution / oxygen evolution reaction catalyst activity according to claim 3, characterized in that: The incident parallel light module is used to provide parallel incident light; The TIR module changes the refractive index by total reflection of parallel incident light at the contact surface between the TIR module and the hydrogen / oxygen evolution catalytic electrode, thereby changing the magnitude of the total reflection light intensity; The imaging detection module is used, on the one hand, to collect reflected light imaging on the surface of the hydrogen evolution / oxygen evolution catalytic electrode to obtain position information, and on the other hand, to detect light intensity changes in real time, and then obtain the refractive index changes of the electrolyte near each channel of the hydrogen evolution / oxygen evolution catalytic electrode based on the relationship between light intensity and refractive index, and then obtain the starting potential when the refractive index changes at the channel on the surface of the hydrogen evolution / oxygen evolution catalytic electrode.

5. The online detection method for the activity of hydrogen evolution / oxygen evolution reaction catalyst according to claim 1 or 2, characterized in that: The potential scanning device module promotes the hydrogen evolution / oxygen evolution reaction to generate bubbles through potential scanning, thereby driving the refractive index of the surface of the hydrogen evolution / oxygen evolution catalytic electrode to change.

6. An online detection device for the activity of a hydrogen evolution / oxygen evolution reaction catalyst, which is detected by the online detection method for the activity of a hydrogen evolution / oxygen evolution reaction catalyst as claimed in claim 1, characterized in that: It includes a hydrogen / oxygen evolution catalytic electrode, a prism-type total reflection system for parallel light incidence, and a potential scanning device module; The hydrogen / oxygen evolution catalytic electrode comprises an electrode substrate, a plurality of channels are arranged on the electrode substrate, and exhaust flow channels are arranged between the channels; the electrode substrate is a graphite plate with a flux of 5×5; The parallel light incident prism type total reflection system comprises an incident parallel light module, a TIR module, and an imaging detection module arranged in sequence; the TIR module comprises a prism, and the prism is kept parallel to the hydrogen evolution / oxygen evolution catalytic electrode and maintained at a distance of several microns to several hundred microns; The incident parallel light module is used to provide parallel incident light; The TIR module changes the refractive index by total reflection of parallel incident light at the contact surface between the TIR module and the hydrogen / oxygen evolution catalytic electrode, thereby changing the magnitude of the total reflection light intensity; The imaging detection module is used to collect reflected light imaging of the surface of the hydrogen evolution / oxygen evolution catalytic electrode to obtain position information, and is used to detect light intensity changes in real time, and then obtain the refractive index changes of the electrolyte near each channel of the hydrogen evolution / oxygen evolution catalytic electrode according to the relationship between light intensity and refractive index, and then obtain the starting potential when the refractive index changes at the channel on the surface of the hydrogen evolution / oxygen evolution catalytic electrode, and characterize the activity of the hydrogen evolution / oxygen evolution reaction catalyst through the starting potential; The potential scanning device module performs potential scanning on the hydrogen / oxygen evolution catalytic electrode to promote the hydrogen / oxygen evolution reaction to generate bubbles, so that the refractive index of the electrolyte at the hydrogen / oxygen evolution catalytic electrode changes, thereby changing the intensity of the TIR reflected light.

7. The online detection device for hydrogen evolution / oxygen evolution reaction catalyst activity according to claim 6, characterized in that: The incident parallel light module includes a point light source and a collimating lens arranged in sequence; The imaging detection module comprises an imaging lens group and a camera which are arranged in sequence; the imaging detection module further comprises a filter which is located between the TIR module and the imaging lens group.

8. The online detection device for hydrogen evolution / oxygen evolution reaction catalyst activity according to claim 6, characterized in that: The potential scanning device module performs potential scanning on the hydrogen / oxygen evolution catalytic electrode through an electrochemical workstation to promote the hydrogen / oxygen evolution reaction to generate bubbles to produce a change in the surface refractive index of the hydrogen / oxygen evolution catalytic electrode.

9. The online detection device for the activity of hydrogen evolution / oxygen evolution reaction catalyst according to any one of claims 6 to 8, characterized in that: It also includes a vacuum sealing device, in which the TIR module and the hydrogen / oxygen evolution catalytic electrode are located, and the vacuum sealing device allows bubbles generated by the hydrogen / oxygen evolution reaction to be discharged along the exhaust flow channel.

10. The online detection device for hydrogen evolution / oxygen evolution reaction catalyst activity according to claim 9, characterized in that: The vacuum sealing device comprises a sealing cover, a vacuum device, a window for incident light and a window for emitting light.

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