An electrochemical in-situ reaction device for time-resolved XAFS testing

Abstract

This invention proposes an electrochemical in-situ reaction device for time-resolved XAFS testing, relating to the field of spectroscopic analysis. It includes a reaction cell with first and second through-holes positioned on opposite sidewalls, a liquid layer thickness adjustment mechanism, a visualization mechanism, and an end-face sealing mechanism located on the side of the second through-hole away from the first through-hole, with a sample mounting position. One end of the visualization mechanism forms a sealed optical window extending into the reaction cell. The liquid layer thickness adjustment mechanism adjusts the distance between the optical window and the second through-hole. When the end-face sealing mechanism is sealed to the reaction cell, the sample mounting position faces inwards. This invention precisely adjusts the liquid layer thickness by precisely adjusting the distance between the optical window and the second through-hole through the liquid layer thickness adjustment mechanism, enabling the application of millisecond-level time-resolved XAFS technology in the direction of electrochemical liquid-phase reactions, providing a high-precision in-situ reaction device.

Description

Technical Field

[0001] This invention relates to the field of spectroscopic analysis and testing technology, and more specifically, to an electrochemical in-situ reaction device for time-resolved XAFS testing, which is particularly suitable for the precise observation of the dynamic structural evolution of catalytic materials in electrochemical and electrocatalytic research. Background Technology

[0002] XAFS, or X-ray absorption fine structure, is a powerful technique for characterizing local structures and an important means of studying the local atomic and electronic structures of matter. Real-time acquisition of XAFS spectroscopic data of catalytic materials during electrochemical reactions is crucial for studying the structural changes of catalysts and catalytic electrode materials during the reaction process. In-situ XAFS reaction cells are key devices for conducting such experiments. They typically operate in transmission or fluorescence mode, allowing the introduction of reaction atmospheres such as CO2 and O2, and are compatible with electrolytes including but not limited to strong acid or strong base environments. They provide a controllable electrochemical environment and allow X-rays to penetrate the sample and the surrounding liquid layer. When operating in transmission mode, the thickness of the electrolyte layer in an in-situ XAFS reaction cell needs to be strictly optimized. An excessively thick layer will strongly absorb X-rays, leading to signal attenuation, a sharp decrease in the signal-to-noise ratio, or even the inability to detect a useful signal. An excessively thin layer may result in the catalytic electrode not being fully immersed in the electrolyte environment, thus failing to conduct a real electrochemical reaction. Therefore, an optimal balance must be struck between signal intensity acquisition and the effectiveness of the catalytic reaction.

[0003] Existing in-situ XAFS reaction cells typically employ a three-electrode system to construct the electrochemical reaction environment and are equipped with a Kapton membrane optical window. While this window offers some light transmittance, the electrolyte layer thickness is usually coarsely adjusted using a simple screw or manual knob. These cells can be used in desktop XAFS spectrometers or synchrotron radiation experiments, supporting electrochemical measurements. However, when these existing in-situ XAFS reaction cells are applied to millisecond-level time-resolved studies requiring extremely high precision, repeatability, and real-time observation, their inherent limitations become apparent. They suffer from insufficient precision in controlling the electrolyte layer thickness within the reaction cell, failing to meet quantitative analysis needs. Furthermore, this directly leads to a sharp decrease in the signal-to-noise ratio of time-resolved XAFS spectroscopy, or even the complete loss of useful information.

[0004] Millisecond-resolved time-resolution XAFS spectroscopic electrocatalytic assays place extremely high demands on the reaction apparatus. Firstly, the precision required for adjusting the liquid layer thickness must be extremely high, ideally on the order of 0.01 mm. Secondly, high repeatability is required after each thickness adjustment, necessitating precise reproduction of the same conditions across multiple experiments or dynamic processes to ensure the reliability and comparability of the time-resolved data. Since existing in-situ XAFS electrochemical reaction cells cannot be applied to millisecond-resolved time-resolution XAFS experiments, and no publicly available patents disclose time-resolved XAFS reaction apparatus that meets the aforementioned requirements, the lack of in-situ electrochemical XAFS testing devices has become a major technical bottleneck restricting the development of millisecond-resolved time-resolution in-situ XAFS technology, which aims to capture transient intermediates and reveal reaction pathways. Summary of the Invention

[0005] 1. The technical problem that the invention aims to solve

[0006] The thickness of the electrolyte layer significantly impacts the test results of in-situ XAFS reaction cells. However, existing in-situ XAFS reaction cells primarily use a fixed electrolyte layer thickness for testing. Even some in-situ XAFS reaction cells with adjustable electrolyte layer thickness only allow for coarse adjustments, with unclear adjustment amounts and precision. Therefore, directly applying existing in-situ XAFS reaction cells to time-resolved studies results in insufficient precision in controlling the electrolyte layer thickness within the reaction cell. This not only fails to meet the requirements of quantitative analysis but also makes it unsuitable for demanding experiments, hindering the development of time-resolved in-situ XAFS technology. Therefore, this invention aims to propose an electrochemical in-situ reaction device for time-resolved XAFS testing. Through a precisely designed electrolyte layer thickness adjustment mechanism, the electrochemical in-situ reaction device for time-resolved XAFS testing achieves an adjustment precision of 0.01 mm, enabling accurate and repeatable setting of the electrolyte layer thickness adjustment amount. This solution not only meets the quantitative analysis requirements of millisecond-level time-resolved XAFS in-situ electrochemical experiments but also captures transient intermediates in the catalytic material reaction process and reveals the reaction pathway.

[0007] 2. Technical Solution

[0008] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0009] This invention proposes an electrochemical in-situ reaction device for millisecond-level time-resolved XAFS testing, comprising a reaction cell, a liquid layer thickness adjustment mechanism, a visualization mechanism, and an end-face sealing mechanism;

[0010] The reaction tank body has a first through hole and a second through hole through its two opposite side walls, and the positions of the first through hole and the second through hole are corresponding.

[0011] The visualization mechanism is connected to the liquid layer thickness adjustment mechanism, one end of which forms an optical window, and the end forming the optical window extends into the reaction tank body from the side away from the second through hole through the first through hole; the liquid layer thickness adjustment mechanism is used to adjust the distance between the optical window and the second through hole;

[0012] The end-face sealing mechanism is disposed on the side of the second through hole away from the first through hole, and a sample mounting position is provided on the side of the mechanism near the second through hole; when the end-face sealing mechanism is sealed and connected to the side of the reaction tank body from the side of the second through hole away from the first through hole, the sample mounting position faces the inside of the reaction tank body.

[0013] Furthermore, the liquid layer thickness adjustment mechanism is configured as a gear adjustment mechanism;

[0014] The gear adjustment mechanism includes at least a gear transmission element with a first scale and a transmission gear shaft. One end of the transmission gear shaft is connected to the gear transmission element, and the other end is rotatably connected to the visualization mechanism by a threaded connection. When the gear transmission element drives the transmission gear shaft to rotate, the visualization mechanism has the freedom to reciprocate along the axial direction of the transmission gear shaft, thereby adjusting the distance between the optical window and the second through hole.

[0015] Furthermore, it also includes a visual reading mechanism;

[0016] The visual reading mechanism is connected to the gear transmission element and includes a reading unit with a second scale. The reading unit is used to convert the adjustment amount into a visual reading via the second scale when the liquid layer thickness adjustment mechanism adjusts the distance between the optical window and the second through hole.

[0017] Furthermore, the liquid layer thickness adjustment mechanism also includes several sets of gear transmission pairs, a first connecting part, and a second connecting part;

[0018] Let the sidewall of the reaction tank with the first through hole be defined as the first surface, and the sidewall with the second through hole be defined as the second surface, then:

[0019] The second connecting part is disposed on the side of the first through hole away from the second through hole, and is configured as a shell structure connected to the first surface; the side wall of the shell structure opposite to the first through hole is configured as a flat wall, and an adjustment cavity is formed between the flat wall and the first surface, and the visualization mechanism is disposed in the adjustment cavity; a third through hole coaxial with the first through hole is disposed through the flat wall, and a cylindrical countersunk gear groove is disposed on the side of the flat wall away from the first surface, and the gear groove is coaxial with the third through hole;

[0020] The first connecting portion is disposed on the side of the second connecting portion away from the first surface, and includes at least a circular annular panel, wherein the circular annular panel is coaxial with the third through hole;

[0021] The gear transmission element is configured as a gear ring, which is mounted on the end face of the gear groove away from the first face. The annular panel is fitted onto the end of the gear ring away from the first face. A gear mating cavity is formed between the annular panel, the gear ring, and the gear groove. The inner wall surface of the gear mating cavity is provided with gear teeth on the side near the gear groove and with a smooth surface on the side near the first connecting part. The gear ring has a degree of freedom to rotate about its axial direction.

[0022] Each of the gear transmission pairs includes a first gear and a second gear meshing with the first gear. The first gear and the second gear are disposed within the gear mating cavity. One end of the transmission gear shaft is connected to the annular panel by a bearing, and the other end passes through the planar wall, connects to the visualization mechanism, and is then connected to the first surface by a bearing. The first gear is fitted onto the transmission gear shaft and is located within the gear groove. The second gear is connected to the annular panel by a bearing at one end of the gear shaft and to the planar wall by a bearing at the other end. The second gear synchronously meshes with the teeth of the gear ring.

[0023] When the gear ring rotates, the second gear drives the first gear and the transmission gear shaft to rotate, causing the visualization mechanism to reciprocate in the adjustment cavity along the axial direction of the transmission gear shaft.

[0024] Furthermore, the reaction tank is configured as a square tank, and a cylindrical settling trough is provided on the first side of the square tank. The cylindrical settling trough causes the square tank to form a U-shaped structure along a cross section parallel to the axial direction of the first through hole; the first through hole is coaxially disposed at the bottom of the cylindrical settling trough.

[0025] The visualization mechanism includes a visible part, a third connecting part, and a sealing part;

[0026] The visible part includes a first cylinder and a second cylinder, which are connected to form a coaxial frustum-shaped stepped structure; the outer diameter of the first cylinder is larger than the outer diameter of the second cylinder, and the outer diameter of the first cylinder is adapted to the inner diameter of the cylindrical recess; the optical window seals the end face of the second cylinder from the end of the second cylinder away from the first cylinder, and the outer diameter of the second cylinder is smaller than the diameter of the first through hole.

[0027] The third connecting portion is circumferentially disposed at the end of the first cylinder away from the second cylinder and extends outward along the radial direction of the second cylinder; the third connecting portion is provided with a plurality of mounting positions, the number of mounting positions being at least equal to the number of gear transmission pairs, and the position of the mounting position corresponding to the position of the transmission gear shaft on which each gear transmission pair is mounted;

[0028] The sealing part is arranged around the outer wall of the first cylinder; when the second cylinder extends into the reaction tank body through the first through hole and the first cylinder is adapted to be installed in the cylindrical settling tank, the sealing part seals the fitting gap between the first cylinder and the cylindrical settling tank.

[0029] Furthermore, the visual reading mechanism includes an indicator gear disposed within the adjustment cavity, the indicator gear constituting a reading unit with a second scale; the inner wall surface of the gear ring encircling the gear teeth forms two sets of gear teeth along its axial direction, one set of gear teeth away from its smooth inner wall meshing with the second gear, and the other set of gear teeth near its smooth inner wall having a single tooth structure, the indicator gear meshing with the single tooth structure;

[0030] The indicator gear includes a circular support plate and indicator teeth; a plurality of counting protrusions are evenly arranged on the side of the circular support plate near the circular panel, the counting protrusions are marked with numbers and are set as hemispherical; a circular support column is provided on the side of the circular support plate near the gear groove, and the indicator teeth are evenly distributed circumferentially on the outer wall of the circular support column.

[0031] A positioning post parallel to the axial direction of the gear groove is provided on the planar wall, and an elastic element is fitted on the positioning post; the indicator gear presses against the elastic element and is fitted onto the positioning post;

[0032] The annular panel has a recessed mating area and a reading area on the side surface near the gear groove. The shape of the recessed mating area is adapted to the shape of the annular support plate, and the bottom surface of the recessed mating area is uniformly provided with a plurality of positioning bosses. The number of positioning bosses is equal to the number of counting bosses, and each positioning boss is configured as a semi-cylindrical shape extending radially along the recessed mating area. The reading area is located on the side surface of the annular panel away from the gear groove, for visualizing the numbers on at least one of the counting bosses.

[0033] When the first connecting part and the second connecting part are connected and fixed via the transmission gear shaft, the positioning boss and the counting boss are staggered and engaged, and the positioning boss and the counting boss are tightly meshed under the action of the elastic element in a compressed state.

[0034] Furthermore, the end-face sealing mechanism includes a sample positioning membrane, a sealing gasket, and an end plate;

[0035] A fourth through hole is provided on the sample positioning membrane at a position corresponding to the second through hole, and the diameter of the fourth through hole is larger than that of the second through hole; the fourth through hole is used to position and place the sample to be tested.

[0036] The sealing gasket is sealed and connected to the side of the sample positioning membrane away from the reaction cell, and is configured as a flat plate structure made of transparent polymer material.

[0037] The end plate is connected to the side of the sealing gasket away from the sample positioning film, and a fifth through hole is provided on its plate surface at the position corresponding to the fourth through hole. The fifth through hole constitutes a reaction observation hole.

[0038] Furthermore, each of the aforementioned mounting positions includes a support plate extending from the outer wall of the first cylindrical end, a transmission nut, and a transmission nut fixing clip; a polygonal through hole is provided through the surface of the support plate, and the transmission nut is adapted to be installed in the polygonal through hole; the inner wall of the transmission nut is threadedly engaged with the transmission gear shaft; the transmission nut fixing clip is fitted onto the support plate from the side of the support plate, and includes two clamping plates opposite to the two side plates of the support plate, each of the two clamping plates having a sixth through hole at a position corresponding to the polygonal through hole, the diameter of the sixth through hole being larger than the outer diameter of the transmission gear shaft and smaller than the diameter of the circumscribed circle of the transmission nut; the transmission nut is confined within the polygonal through hole by the transmission nut fixing clip;

[0039] When the transmission gear shaft rotates, the transmission nut, via the transmission nut fixing clamp, drives the visible part to reciprocate within the adjustment cavity along the axial direction of the transmission gear shaft.

[0040] Furthermore, the liquid layer thickness adjustment mechanism includes two sets of symmetrically arranged gear transmission pairs, and the third connecting part is provided with two mounting positions corresponding to the end of the first cylinder.

[0041] Furthermore, it is configured as a three-electrode system, including a reference electrode, a counter electrode, and a working electrode;

[0042] Define the first surface as the top surface of the reaction cell and the second surface as the bottom surface of the reaction cell. Then, two electrode mounting holes are provided on one side of the reaction cell, which are connected to the inside of the reaction cell. The two electrode mounting holes are used to seal and install the reference electrode and the counter electrode, respectively. The working electrode is led out by the end face sealing mechanism when the sample to be tested is installed.

[0043] Furthermore, an electrolyte inlet and an electrolyte outlet are respectively provided on opposite sides of the reaction tank. The electrolyte inlet, electrolyte outlet, and electrode mounting hole are not on the same side, and the distance between the electrolyte inlet and the bottom surface is less than the distance between the electrolyte outlet and the bottom surface.

[0044] 3. Beneficial effects

[0045] Compared with the prior art, the technical solution provided by this invention has the following advantages:

[0046] (1) The electrochemical in-situ reaction device for time-resolved XAFS testing disclosed in this invention comprises a reaction cell body, a liquid layer thickness adjustment mechanism, a visualization mechanism, and an end-face sealing mechanism; a first through hole and a second through hole corresponding to the positions are provided through the two opposite side walls of the reaction cell body; the visualization mechanism is connected to the liquid layer thickness adjustment mechanism, and one end of the visualization mechanism forms a sealed optical window extending into the reaction cell body; the liquid layer thickness adjustment mechanism is configured as a gear adjustment mechanism for adjusting the distance between the optical window and the second through hole; the end-face sealing mechanism is located on the side of the second through hole away from the first through hole, and a sample mounting position is provided on the side of the second through hole; when the end-face sealing mechanism is sealed and connected to the reaction cell body, the sample mounting position faces the inside of the reaction cell body. This invention indirectly adjusts the liquid layer thickness by setting the liquid layer thickness adjustment mechanism as a gear adjustment mechanism to precisely adjust the distance between the optical window and the second through hole; it can not only quantitatively adjust the liquid layer thickness to meet the quantitative analysis requirements, but also has high repeatability and high practicality.

[0047] (2) The electrochemical in-situ reaction device for time-resolved XAFS testing disclosed in this invention achieves precise adjustment of the distance between the visualization mechanism and the second through hole through the transmission cooperation between the gear ring with the first scale, the transmission gear shaft and the gear transmission pair; by designing the transmission ratio of the first gear and the second gear in the gear ring and the gear transmission pair, the adjustment accuracy is improved to the order of 0.01 mm; compared with the non-quantitative liquid layer thickness adjustment method based on simple screw or manual knob in the in-situ XAFS reaction cell of the prior art, the adjustment accuracy is high and thus can be applied to time-resolved research with high requirements. In dynamic experiments, the same conditions can be reproduced quickly and with high accuracy, which significantly improves the reliability and comparability of time-resolved data.

[0048] (3) The electrochemical in-situ reaction device for time-resolved XAFS testing disclosed in this invention is equipped with a visual reading mechanism. The visual reading mechanism is provided with a reading unit with a second scale, that is, a display gear containing a counting boss meshes with a gear ring. The rotation of the gear ring drives the display gear to rotate, thereby causing the counting boss corresponding to the reading area to rotate and change the count. Through scale calibration between the first scale and the second scale, and by determining the transmission ratio of the first gear and the second gear in the gear ring and gear transmission pair, the current liquid layer thickness can be accurately and visually read.

[0049] (4) The electrochemical in-situ reaction device for time-resolved XAFS testing disclosed in this invention sets the visualization structure as a cylindrical stepped structure composed of two cylindrical sections to fit the cylindrical sedimentation tank on the side wall of the reaction cell, and performs movable sealing through the sealing part to form an electrolyte tank with variable volume in the reaction cell; this visualization mechanism is not only easy to operate and use, but also can be quickly changed in position and can be efficiently applied to dynamic experimental environments.

[0050] (5) The electrochemical in-situ reaction device for time-resolved XAFS testing disclosed in this invention sets the end-face sealing mechanism to consist of a sample positioning membrane, a sealing gasket, and an end plate. The sample positioning membrane is provided with a fourth through hole for installing the sample to be tested, the sealing gasket is made of transparent material, and the end plate is provided with a reaction observation hole. This allows the sample reaction process to be directly observed at the through holes on both sides of the reaction cell, including observing the state changes on the surface of the working electrode, such as the generation and distribution of bubbles, corrosion or detachment of electrode materials, etc. In the time-resolved experiment, the direct observation mode can correlate the measured XAFS spectral data with the real-time reaction phenomena, which can not only capture transient intermediates and reveal the reaction path, but also help to deeply understand the reaction mechanism.

[0051] (6) The electrochemical in-situ reaction device for time-resolved XAFS testing disclosed in this invention can precisely control the liquid layer thickness for quantitative analysis, fully solve the technical problem of poor XAFS signal caused by the uncertainty of liquid layer thickness, overcome the technical bottleneck that the current in-situ XAFS reaction cell cannot be applied to the high-requirement millisecond-level time-resolved in-situ XAFS research, and has broad application prospects. Attached Figure Description

[0052] Figure 1 This is an exploded view of the electrochemical in-situ reaction apparatus for time-resolved XAFS testing disclosed in this invention;

[0053] Figure 2 This is a main assembly diagram of the electrochemical in-situ reaction device for time-resolved XAFS testing disclosed in this invention.

[0054] Figure 3This is a cross-sectional view of the electrochemical in-situ reaction apparatus for time-resolved XAFS testing disclosed in this invention;

[0055] Figure 4 This is a schematic diagram of the gear adjustment mechanism in the electrochemical in-situ reaction device for time-resolved XAFS testing disclosed in this invention.

[0056] Figure 5 This is a perspective view of the display gear in the electrochemical in-situ reaction device for time-resolved XAFS testing disclosed in this invention.

[0057] Figure 6 This is a perspective view of the first connection part in the electrochemical in-situ reaction device for time-resolved XAFS testing disclosed in this invention;

[0058] Figure 7 This is a schematic diagram of the indicator gear engagement in the electrochemical in-situ reaction device for time-resolved XAFS testing disclosed in this invention;

[0059] Figure 8 The electrochemical in-situ reaction apparatus disclosed in this invention is used to determine the L-edge time-resolved XAFS spectrum of iridium (Ir).

[0060] The specific meanings of each mark in the diagram are as follows:

[0061] 1-First fixing bolt; 2-First bearing; 3-Transmission gear shaft; 4-Indicator gear; 41-Circular ring support plate; 42-Indicator gear tooth; 43-Counting boss; 5-Elastic element; 6-Second bearing; 7-Transmission nut fixing clip; 71-Sixth through hole; 8-Transmission nut; 9-Third bearing; 10-Electrolyte outlet; 11-Electrode sealing screw; 12-End plate fixing bolt; 13-First connecting part; 131-Circular ring panel; 132-Matching boss; 14-Gear ring; 15-Gear Gear drive pair, 151-first gear, 152-second gear; 16-second connecting part, 161-gear groove, 162-positioning post, 163-third through hole; 17-limiting post; 18-visible part, 181-optical window; 19-sealing part; 20-reaction cell body; 201-first through hole; 21-electrolyte inlet; 22-sample positioning membrane, 221-fourth through hole; 23-sealing gasket; 24-end plate, 241-fifth through hole; 25-third connecting part; 26-reading area. Detailed Implementation

[0062] To further understand the content of this invention, a detailed description of the invention will be provided in conjunction with the accompanying drawings.

[0063] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0064] The electrochemical in-situ reaction apparatus for time-resolved XAFS testing disclosed in this invention will be further described below with reference to the embodiments shown in the accompanying drawings.

[0065] Combination Figure 1 As shown, the present invention proposes an electrochemical in-situ reaction device for time-resolved XAFS testing, including a reaction cell 20, a liquid layer thickness adjustment mechanism, a visualization mechanism, and an end face sealing mechanism.

[0066] In terms of specific structure, a first through hole 201 and a second through hole are provided through the two opposite sidewalls of the reaction tank 20, and the positions of the first through hole 201 and the second through hole are corresponding; the visualization mechanism is connected to the liquid layer thickness adjustment mechanism, one end of which forms an optical window 181, and the end of the optical window 181 extends into the reaction tank 20 from the side of the first through hole 201 away from the second through hole; the liquid layer thickness adjustment mechanism is used to adjust the distance between the optical window 181 and the second through hole; the end face sealing mechanism is provided on the side of the second through hole away from the first through hole 201, and a sample mounting position is provided on the side of the second through hole close to the second through hole; when the end face sealing mechanism is sealed and connected to the side of the reaction tank 20 from the side of the second through hole away from the first through hole 201, the sample mounting position faces the inside of the reaction tank 20. That is, the sample to be tested is installed at the position of the second through hole. When the liquid layer thickness adjustment mechanism adjusts the distance between the optical window 181 and the second through hole, it essentially adjusts the liquid layer thickness of the electrolyte when the optical window 181 observes the sample in the reaction cell 20. The liquid layer thickness is indirectly adjusted by adjusting the visualization mechanism through the liquid layer thickness adjustment mechanism, which allows for more precise adjustment and control of the adjustment amount compared to traditional adjustment methods.

[0067] Meanwhile, the solution sets the liquid layer thickness adjustment mechanism and the visualization mechanism on the side of the first through hole 201, with the visualization mechanism forming an observation port on one side; the end face sealing mechanism is set on the side of the second through hole, and through structural design, it not only achieves sealing but can also be used to form an observation port on the opposite side; the two observation ports work together to intuitively observe the reaction phenomena of the sample reaction process, and thus combine with the measured XAFS spectral data for analysis, to obtain more accurate characterization of the sample.

[0068] The electrochemical in-situ reaction device for time-resolved XAFS testing provided by this invention is designed as a three-electrode system in sync with existing in-situ XAFS reaction cells. The reference electrode and the counter electrode extend directly into the cell through preset holes in the reaction cell body 20. The working electrode is connected to the sample to be tested and led out after installation through the end-face sealing mechanism, so that the reaction phenomena generated around the working electrode can be directly observed through the observation port.

[0069] Further integration Figure 1 As shown, to achieve more precise adjustment accuracy, the liquid layer thickness adjustment mechanism is configured as a gear adjustment mechanism. This gear adjustment mechanism includes at least a gear transmission element with a first scale and a transmission gear shaft 3. One end of the transmission gear shaft 3 is connected to the gear transmission element, and the other end is rotatably connected to the visualization mechanism by a threaded connection. Thus, when the gear transmission element provides power, including manual, electric, or pneumatic power, it drives the transmission gear shaft 3 to rotate, giving the visualization mechanism the freedom to reciprocate along the axial direction of the transmission gear shaft 3, thereby adjusting the distance between the optical window 181 and the second through hole.

[0070] Specific combination Figure 3 and Figure 4 As shown, the liquid layer thickness adjustment mechanism also includes several sets of gear transmission pairs 15, a first connecting part 13, and a second connecting part 16;

[0071] If we define the sidewall of the reaction tank body 20 with the first through hole 201 as the first surface and the sidewall with the second through hole as the second surface, then:

[0072] The second connecting part 16 is disposed on the side of the first through hole 201 away from the second through hole, and is configured as a shell structure connected to the first surface; the side wall of the shell structure opposite to the first through hole 201 is configured as a flat wall, and an adjustment cavity is formed between the flat wall and the first surface, and the visualization mechanism is partially disposed in the adjustment cavity; a third through hole 163 coaxial with the first through hole 201 is disposed through the flat wall, and a cylindrical countersunk gear groove 161 is disposed on the side of the flat wall away from the first surface, the gear groove 161 being coaxial with the third through hole 163. In the embodiment shown in the figure, the reaction tank 20 is configured as a square tank, and the shell structure of the second connecting part 16 is configured as a square shell with an open bottom, the size of the square shell being similar to or equal to that of the square tank; in the embodiment, the bottom surface size of the square shell opening is equal to the first surface size of the square tank, and the end face of the opening is directly and fixedly connected to the first surface. For example, a limiting post 17 is provided on any side of the end face of the square shell, and a limiting hole is provided at the corresponding position on the first surface. The square shell and the square pool are fixedly connected by the interference fit between the limiting post 17 and the limiting hole.

[0073] The first connecting part 13 is disposed on the side of the second connecting part 16 away from the first surface, and includes at least a circular annular panel 131. The circular annular panel 131 is coaxial with the third through hole 163. The circular annular panel 131 forms the groove cover of the gear groove 161. The purpose of setting the third through hole 163 and the circular annular panel 131 to be coaxial is to reserve observation space for the optical window 181 of the visualization mechanism.

[0074] The gear transmission element is configured as a gear ring 14, such as... Figure 3 As shown, the gear ring 14 is mounted on the end face of the gear groove 161 away from the first face, and the annular panel 131 is fitted into the end of the gear ring 14 away from the first face; specifically, the outer edge of the end of the gear ring 14 extends with a flange towards the first connecting part 13, so that a groove-like groove is formed in the middle of the end face of the gear ring 14, and the annular panel 131 is fitted into the groove-like groove.

[0075] Ultimately, a gear mating cavity is formed between the annular panel 131, the gear ring 14, and the gear groove 161. To facilitate gear transmission, the gear ring 14 is designed as an internal gear ring, meaning that the inner wall of the gear ring 14 forming the gear mating cavity has teeth on the side near the gear groove 161 and a smooth surface on the side near the first connecting part 13. Furthermore, since the gear ring 14 is not fastened to the first connecting part 13 or the second connecting part 16, it has the freedom to rotate around its axial direction, allowing it to be manually rotated. For ease of reading, in this embodiment, the first graduation corresponding to the gear ring 14 is marked on the annular panel 131 according to the number of its teeth.

[0076] Each of the gear transmission pairs 15 includes a first gear 151 and a second gear 152 meshing with the first gear 151, wherein the first gear 151 and the second gear 152 are disposed within the gear mating cavity; one end of the transmission gear shaft 3 is equipped with a bearing. Figure 1 The first bearing 2 is connected to a pre-set countersunk hole on the annular panel 131, and the other end passes through the planar wall to connect to the visualization mechanism via a bearing. Figure 1The third bearing 9 is connected to a pre-set countersunk hole on the first surface. The first gear 151 is fitted onto the transmission gear shaft 3 and located within the gear groove 161. In a specific implementation, a bearing, designated as the second bearing 6, is also provided at the point where the transmission gear shaft 3 penetrates the planar wall. The first bearing 2, the second bearing 6, and the third bearing 9 are used to achieve low-resistance rotation of the transmission gear shaft 3. The second gear 152 is connected to the annular panel 131 via a bearing at one end of the gear shaft and to the planar wall via a bearing at the other end. The second gear 152 synchronously meshes with the teeth of the gear ring 14. The connection structure of the second gear 152 with the gear shaft, the annular panel 131, and the planar wall is the same as the fixing structure of the transmission gear shaft 3.

[0077] When the gear ring 14 rotates, the second gear 152 drives the first gear 151 and the transmission gear shaft 3 to rotate, causing the visualization mechanism to reciprocate in the adjustment cavity along the axial direction of the transmission gear shaft 3, thereby achieving precise control of the movement distance of the visualization mechanism.

[0078] To prevent unstable connection between the first connecting part 13 and the second connecting part 16, as shown in the figure, fixing bolt holes are provided on the annular panel 131 at positions corresponding to the outer plane wall of the gear groove 161. After the annular panel 131, the gear ring 14, and the second connecting part 16 are installed, the fixing bolts at the corresponding positions are connected and tightened using the first fixing bolt 1. Furthermore, to prevent dust from entering the gear mating cavity through the through hole in the middle of the annular panel 131 and affecting gear transmission, a cylindrical protective shell extends from the end of the through hole in the middle of the annular panel 131 near the gear groove 161 towards the gear groove 161. Figure 6 As shown, the end face of the cylindrical protective shell abuts against the groove surface of the gear groove 161 after the gear mating cavity is formed.

[0079] Further integration Figure 1 and Figure 3 As shown, based on the design of the gear adjustment mechanism described above, the structure of the reaction tank 20 and the visualization mechanism is described in detail below. A cylindrical groove is provided on the first surface of the reaction tank 20, which causes the square tank body to form a U-shaped structure along a cross-section parallel to the axial direction of the first through hole 201; the first through hole 201 is coaxially disposed at the bottom of the cylindrical groove. Defining the first surface as the top surface of the reaction tank 20 and the second surface as the bottom surface of the reaction tank 20, two electrode mounting holes are provided on one side of the reaction tank 20, connecting to the interior of the reaction tank 20. Electrode sealing screws 11 are respectively provided in the two electrode mounting holes for sealing and mounting the reference electrode and the counter electrode. When installing the sample to be tested, the working electrode is attached to one end of the sample to be tested using external copper tape, and the sample positioning film 22 leads out of the reaction tank 20 to connect to external power.

[0080] Meanwhile, an electrolyte inlet 21 and an electrolyte outlet 10 are respectively provided on opposite sides of the reaction tank 20. The electrolyte inlet 21, the electrolyte outlet 10 and the electrode mounting hole are not on the same side, and the distance between the electrolyte inlet 21 and the bottom surface is less than the distance between the electrolyte outlet 10 and the bottom surface. The electrolyte inlet 21 and the electrolyte outlet 10 are respectively used to connect to external fixed water pipes to realize the inflow and outflow of electrolyte. The height difference between the inlet and outlet forms a flow pattern of bottom inflow and top outflow, which can effectively prevent bubbles from accumulating on the surface of the working electrode and ensure the stability of the reaction interface and uniform mass transfer.

[0081] The visualization mechanism includes a visible part 18, a third connecting part 25, and a sealing part 19;

[0082] like Figure 3 As shown, the visible part 18 includes a first cylinder and a second cylinder, which are connected to form a coaxial frustum-shaped stepped structure. The outer diameter of the first cylinder is larger than the outer diameter of the second cylinder, and the outer diameter of the first cylinder is adapted to the inner diameter of the cylindrical recess. The optical window 181 seals the end face of the second cylinder from the end of the second cylinder away from the first cylinder, forming an observation port. The outer diameter of the second cylinder is smaller than the diameter of the first through hole 201, so that the second cylinder can freely enter and exit the adjustment cavity. Optionally, the diameter of the cylindrical protective shell is equal to the inner diameter of the cylindrical recess.

[0083] The third connecting part 25 is circumferentially disposed at the end of the first cylinder away from the second cylinder and extends outward along the radial direction of the second cylinder; the third connecting part 25 is provided with a plurality of mounting positions, the number of mounting positions being at least equal to the number of gear transmission pairs 15, and the position of the mounting position corresponding to the position of the transmission gear shaft 3 on which each gear transmission pair 15 is mounted, so that the two can be rotatably connected.

[0084] The sealing part 19 is circumferentially disposed on the outer wall of the first cylinder. When the second cylinder extends into the reaction tank 20 through the first through hole 201 and the first cylinder is fitted into the cylindrical settling tank, the sealing part 19 seals the mating gap between the first cylinder and the cylindrical settling tank, thereby preventing electrolyte leakage. In this embodiment, the sealing part 19 is composed of a sealing ring; a sealing groove is provided on the outer wall of the first cylinder near the second cylinder, and the sealing ring is disposed in the sealing groove, thereby deforming the mating part of the first cylinder and the cylindrical settling tank to obtain a reliable sealing effect.

[0085] Figure 1In the described embodiment, the liquid layer thickness adjustment mechanism includes two sets of symmetrically arranged gear transmission pairs 15, and the third connecting part 25 is provided with two mounting positions corresponding to the end of the first cylinder.

[0086] Optionally, any of the mounting positions includes a support plate extending from the outer wall of the first cylindrical end, a transmission nut 8, and a transmission nut fixing clip 7; the support plate has a polygonal through hole through its surface, and the transmission nut 8 is adapted to be installed in the polygonal through hole; the inner wall of the transmission nut 8 is threadedly engaged with the transmission gear shaft 3, specifically, the outer wall of the transmission gear shaft 3 is provided with a fine-tooth external thread, and the inner wall of the transmission nut 8 is provided with a fine-tooth internal thread, and the fine-tooth external thread and the fine-tooth internal thread mesh.

[0087] The transmission nut fixing clip 7 is fitted onto the support plate from the side of the support plate, and includes two clamping plates opposite to the two side plates of the support plate. The two clamping plates are respectively provided with a sixth through hole 71 at the position corresponding to the polygonal through hole. The diameter of the sixth through hole 71 is larger than the outer diameter of the transmission gear shaft 3 so that the transmission gear shaft 3 can pass through, and smaller than the diameter of the outer circle of the transmission nut 8 so as to prevent the transmission nut 8 from falling off. The transmission nut 8 is confined in the polygonal through hole by the transmission nut fixing clip 7, thereby realizing the integrated assembly of the visible part 18 and the transmission nut 8.

[0088] When moving, when the transmission gear shaft 3 is driven to rotate by the gear transmission pair 15, the transmission nut 8 is driven by the transmission nut fixing clamp 7 to move the visible part 18 back and forth in the adjustment cavity along the axial direction of the transmission gear shaft 3, thereby realizing the adjustment of a small distance or a set adjustment amount.

[0089] As an optional embodiment, the gear ring 14 has a module of 1.5 mm and contains 50 teeth. The second gear 152 includes two sets of teeth, one set meshing with the gear ring 14 and the other set meshing with the first gear 151; wherein, the tooth surface module of the gear 152 meshing with the gear ring 14 is 1.5 mm and contains 10 teeth; the tooth surface module of the gear 152 meshing with the first gear 151 is 0.7 mm and contains 10 teeth. The first gear 151 has a module of 0.7 mm and contains 30 teeth. The total transmission ratio of the liquid layer thickness adjustment mechanism is 5:3, and the thread pitch of the transmission gear shaft 3 is 0.6 mm. Therefore, when the gear ring 14 rotates one revolution, the optical window 181 moves 1 mm, and 10 scale points are evenly marked on the outer side of the annular panel 131 to achieve a liquid layer thickness adjustment of 0.1 mm, improving the adjustment accuracy to the 0.01 mm level.

[0090] Further integration Figure 1As shown, the end-face sealing mechanism includes a sample positioning membrane 22, a sealing gasket 23, and an end plate 24. In the figure, a fourth through-hole 221 is provided on the sample positioning membrane 22 at a position corresponding to the second through-hole. The diameter of the fourth through-hole 221 is larger than that of the second through-hole. The fourth through-hole 221 is used to position and place the sample to be tested, preventing the sample from directly entering the reaction cell 20 and becoming unobservable. The sealing gasket 23 is sealed and connected to the side of the sample positioning membrane 22 away from the reaction cell 20. It is a flat plate structure made of a transparent polymer material, such as a polyimide film. Its core purpose is to prevent electrolyte leakage from the second through-hole and the fourth through-hole 221. The end plate 24 is connected to the side of the sealing gasket 23 away from the sample positioning membrane 22. A fifth through hole 241 is provided on its plate surface at the position corresponding to the fourth through hole 221. The fifth through hole 241 constitutes a reaction observation hole to observe the state changes on the surface of the working electrode, such as the generation and distribution of bubbles, corrosion or detachment of electrode materials, etc. During assembly, the sample positioning membrane 22, the sealing gasket 23 and the end plate 24 can be set to the same size, and the mounting holes are set synchronously. The end plate fixing bolts 12 are used to tightly press and solidify the end plate 24 to the reaction tank body 20 from the side away from the sealing gasket 23.

[0091] Combination Figure 1 , Figures 5 to 7 As shown, the electrochemical in-situ reaction device for time-resolved XAFS testing disclosed in this invention also includes a visual reading mechanism; the visual reading mechanism is connected to the gear transmission element and includes a reading unit with a second scale, the reading unit being used to convert the adjustment amount into a visual reading via the second scale when the liquid layer thickness adjustment mechanism adjusts the distance between the optical window 181 and the second through hole.

[0092] Specifically, the visual reading mechanism includes an indicator gear 4 disposed within the adjustment cavity, i.e., the indicator gear 4 constitutes a reading unit with a second scale; the inner wall surface of the gear ring 14, which encircles the teeth, forms two sets of teeth along its axial direction, one set of teeth away from its smooth inner wall meshing with the second gear 152, and the other set of teeth near its smooth inner wall having a single-tooth structure, with the indicator gear 4 meshing with the single-tooth structure. Figure 5 As shown, the indicator gear 4 includes a circular support plate 41 and indicator teeth 42; the circular support plate 41 has a plurality of counting protrusions 43 evenly arranged on the side plate near the circular panel 131, the counting protrusions 43 are marked with numbers and are set in a hemispherical shape; the side plate of the circular support plate 41 near the gear groove 161 extends to the gear groove 161 and is provided with a circular support column, the indicator teeth 42 are evenly distributed on the outer wall of the circular support column and mesh with the single tooth structure of the gear ring 14;

[0093] A positioning post 162 parallel to the axial direction of the gear groove 161 is provided on the planar wall. An elastic element 5, usually a spring, is fitted on the positioning post 162. The indicator gear 4 presses the elastic element 5 and is fitted onto the positioning post 162.

[0094] The annular panel 131 has a groove mating area and a reading area 26 on the side plate near the gear groove 161. The shape of the groove mating area is adapted to the shape of the annular support plate 41, and both are set as circles. The bottom surface of the groove mating area is uniformly provided with a plurality of matching bosses 132. The number of matching bosses 132 is equal to the number of counting bosses 43. Each of the matching bosses 132 is set as a semi-cylindrical shape extending radially along the groove mating area. The reading area 26 is set on the side plate of the annular panel 131 away from the gear groove 161, and is used to make the numbers on at least one of the counting bosses 43 visible.

[0095] When the first connecting part 13 and the second connecting part 16 are connected and fixed via the transmission gear shaft 3, the positioning boss 132 and the counting boss 43 are staggered and engaged, and the positioning boss 132 and the counting boss 43 are tightly meshed under the action of the elastic element 5 in a compressed state. Optionally, the reading area 26 is set as a through-hole that penetrates the settling groove mating area, and the through-hole corresponds to one counting boss 43; or the plate surface of the settling groove mating area is directly set as a transparent material to form the reading area 26, so as to directly observe the change of the value at the mark.

[0096] Based on the gear parameter design of the aforementioned liquid layer thickness adjustment mechanism, the gear end of the indicator gear 4 is designed as follows:

[0097] The module is 1.5mm, containing 10 teeth, which cooperate with the single-tooth structure of the gear ring 14. When the liquid layer thickness adjustment mechanism drives the gear ring 14 to rotate one revolution, thereby driving the transmission nut 8 and the visible part 18 to move precisely 1mm, the single-tooth structure of the gear ring 14 will drive the indicator gear 4 to rotate exactly 1 / 10 revolution, that is, one tooth. The top of the counting boss 43 of the indicator gear 4 is engraved with a numerical scale from 0 to 9. Its rotation position can be seen through the reading area 26 of the first connecting part 13. For each revolution of the gear ring 14, the corresponding liquid layer thickness changes by 1mm, and the number displayed by the indicator gear 4 increases or decreases by 1, thereby directly and intuitively reading the millimeter value of the liquid layer thickness.

[0098] Compared with the prior art, this invention can not only quantitatively adjust the liquid layer thickness and achieve an adjustment accuracy of 0.01 mm, but also intuitively read the current liquid layer thickness while keeping the overall liquid layer thickness of the reaction tank constant. It is convenient, efficient and highly repeatable, and fully meets the application requirements of time-resolved in-situ XAFS counting.

[0099] Figure 8 The image shows an example of an electrochemical in-situ reaction device for time-resolved XAFS testing disclosed in this invention, which uses energy-dispersive X-ray absorption fine structure spectroscopy to monitor in-situ electrochemical processes. The acquisition of the L-edge time-resolved X-ray absorption fine structure spectrum of iridium (Ir) was completed by the BL05U beamline of the Shanghai Synchrotron Radiation Facility (SSRF). The application process of this device is as follows: First, a uniformly dispersed sample slurry is quantitatively loaded onto the surface of a carbon cloth substrate using a spraying device to form a uniform catalytic electrode. This catalytic electrode is then assembled into the reaction cell 20 as the working electrode. By precisely adjusting the spatial position of the reaction cell 20, the dispersive X-ray beam generated by the beamline is accurately focused on the catalytic region of the working electrode, ensuring that the X-rays are effectively received by the position-sensitive detector in transmission mode after penetrating the sample. Key experimental parameters are: X-ray source energy 11.2 keV; single spectral exposure time 4.2 ms; system effective time resolution 60 ms; electrochemical testing is performed in 1 M perchloric acid electrolyte, with the optical window 181 locked to a sample electrolyte thickness of 0.5 mm by rotating the toothed ring 14; the working electrode is tested using linear scanning voltammetry at a scan rate of 10 mV / s within a potential window of 1.5 V to 1.7 V (vs. RHE). During implementation, X-ray spectral acquisition and electrochemical potential application are strictly synchronized, thereby achieving in-situ real-time dynamic monitoring of the catalyst structure evolution during electrocatalysis.

[0100] The present invention and its embodiments have been described above illustratively. This description is not restrictive and is merely one embodiment of the present invention, and is not actually limited thereto. Therefore, if researchers in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. An electrochemical in-situ reaction apparatus for time-resolved XAFS testing, characterized by, This includes the reaction tank body, liquid layer thickness adjustment mechanism, visualization mechanism, and end face sealing mechanism; The reaction tank body has a first through hole and a second through hole through its two opposite side walls, and the positions of the first through hole and the second through hole are corresponding. The visualization mechanism is connected to the liquid layer thickness adjustment mechanism, one end of which forms an optical window, and the end forming the optical window extends into the reaction tank body from the side away from the second through hole through the first through hole; the liquid layer thickness adjustment mechanism is used to adjust the distance between the optical window and the second through hole; The end face sealing mechanism is disposed on the side of the second through hole away from the first through hole, and a sample mounting position is provided on its side near the second through hole; when the end face sealing mechanism is sealed and connected to the side of the reaction tank body from the side of the second through hole away from the first through hole, the sample mounting position faces the inside of the reaction tank body; The liquid layer thickness adjustment mechanism is configured as a gear adjustment mechanism; The gear adjustment mechanism includes at least a gear transmission element with a first scale and a transmission gear shaft. One end of the transmission gear shaft is connected to the gear transmission element, and the other end is rotatably connected to the visualization mechanism by a threaded connection. When the gear transmission element drives the transmission gear shaft to rotate, the visualization mechanism has the freedom to reciprocate along the axial direction of the transmission gear shaft, thereby adjusting the distance between the optical window and the second through hole. The liquid layer thickness adjustment mechanism also includes several sets of gear transmission pairs, a first connecting part, and a second connecting part; Let the sidewall of the reaction tank with the first through hole be defined as the first surface, and the sidewall with the second through hole be defined as the second surface, then: The second connecting part is disposed on the side of the first through hole away from the second through hole, and is configured as a shell structure connected to the first surface; the side wall of the shell structure opposite to the first through hole is configured as a flat wall, and an adjustment cavity is formed between the flat wall and the first surface, and the visualization mechanism is disposed in the adjustment cavity; a third through hole coaxial with the first through hole is disposed through the flat wall, and a cylindrical countersunk gear groove is disposed on the side of the flat wall away from the first surface, and the gear groove is coaxial with the third through hole; The first connecting portion is disposed on the side of the second connecting portion away from the first surface, and includes at least an annular panel, wherein the annular panel is coaxial with the third through hole; The gear transmission element is configured as a gear ring, which is mounted on the end face of the gear groove away from the first face. The annular panel is fitted onto the end of the gear ring away from the first face. A gear mating cavity is formed between the annular panel, the gear ring, and the gear groove. The inner wall surface of the gear mating cavity is provided with gear teeth on the side near the gear groove and with a smooth surface on the side near the first connecting part. The gear ring has a degree of freedom to rotate about its axial direction. Each of the gear transmission pairs includes a first gear and a second gear meshing with the first gear. The first gear and the second gear are disposed within the gear mating cavity. One end of the transmission gear shaft is connected to the annular panel by a bearing, and the other end passes through the planar wall, connects to the visualization mechanism, and is then connected to the first surface by a bearing. The first gear is fitted onto the transmission gear shaft and is located within the gear groove. The second gear is connected to the annular panel by a bearing at one end of the gear shaft and to the planar wall by a bearing at the other end. The second gear synchronously meshes with the teeth of the gear ring. When the gear ring rotates, the second gear drives the first gear and the transmission gear shaft to rotate, causing the visualization mechanism to reciprocate in the adjustment cavity along the axial direction of the transmission gear shaft.

2. The electrochemical in-situ reaction apparatus for time-resolved XAFS testing according to claim 1, characterized in that, It also includes a visual reading mechanism; The visual reading mechanism is connected to the gear transmission element and includes a reading unit with a second scale. The reading unit is used to convert the adjustment amount into a visual reading via the second scale when the liquid layer thickness adjustment mechanism adjusts the distance between the optical window and the second through hole.

3. The electrochemical in-situ reaction apparatus for time-resolved XAFS testing according to claim 1, characterized in that, The reaction tank is configured as a square tank, and a cylindrical settling trough is provided on the first side of the square tank. The cylindrical settling trough causes the square tank to form a U-shaped structure along a cross section parallel to the axis of the first through hole. The first through hole is coaxially disposed at the bottom of the cylindrical settling trough. The visualization mechanism includes a visible part, a third connecting part, and a sealing part; The visible part includes a first cylinder and a second cylinder, which are connected to form a coaxial frustum-shaped stepped structure; the outer diameter of the first cylinder is larger than the outer diameter of the second cylinder, and the outer diameter of the first cylinder is adapted to the inner diameter of the cylindrical recess; the optical window seals the end face of the second cylinder from the end of the second cylinder away from the first cylinder, and the outer diameter of the second cylinder is smaller than the diameter of the first through hole. The third connecting portion is circumferentially disposed at the end of the first cylinder away from the second cylinder and extends outward along the radial direction of the second cylinder; the third connecting portion is provided with a plurality of mounting positions, the number of mounting positions being at least equal to the number of gear transmission pairs, and the position of the mounting position corresponding to the position of the transmission gear shaft on which each gear transmission pair is mounted; The sealing part is arranged around the outer wall of the first cylinder; when the second cylinder extends into the reaction tank body through the first through hole and the first cylinder is adapted to be installed in the cylindrical settling tank, the sealing part seals the fitting gap between the first cylinder and the cylindrical settling tank.

4. The electrochemical in-situ reaction apparatus for time-resolved XAFS testing according to claim 2, characterized in that, The visual reading mechanism includes an indicator gear disposed in the adjustment cavity; the inner wall surface of the gear ring is formed with two sets of gear teeth along its axial direction, one set of gear teeth away from its smooth inner wall meshes with the second gear, and the other set of gear teeth close to its smooth inner wall is a single tooth structure, and the indicator gear meshes with the single tooth structure. The indicator gear includes a circular support plate and indicator teeth; a plurality of counting protrusions are evenly arranged on the side of the circular support plate near the circular panel, the counting protrusions are marked with numbers and are set as hemispherical; a circular support column is provided on the side of the circular support plate near the gear groove, and the indicator teeth are evenly distributed circumferentially on the outer wall of the circular support column. A positioning post parallel to the axial direction of the gear groove is provided on the planar wall, and an elastic element is fitted on the positioning post; the indicator gear presses against the elastic element and is fitted onto the positioning post; The annular panel has a recessed mating area and a reading area on the side surface near the gear groove. The shape of the recessed mating area is adapted to the shape of the annular support plate, and the bottom surface of the recessed mating area is uniformly provided with a plurality of positioning bosses. The number of positioning bosses is equal to the number of counting bosses, and each positioning boss is configured as a semi-cylindrical shape extending radially along the recessed mating area. The reading area is located on the side surface of the annular panel away from the gear groove, for visualizing the numbers on at least one of the counting bosses. When the first connecting part and the second connecting part are connected and fixed via the transmission gear shaft, the positioning boss and the counting boss are staggered and engaged, and the positioning boss and the counting boss are tightly meshed under the action of the elastic element in a compressed state.

5. The electrochemical in-situ reaction apparatus for time-resolved XAFS testing according to claim 1, characterized in that, The end-face sealing mechanism includes a sample positioning membrane, a sealing gasket, and an end plate; A fourth through hole is provided on the sample positioning membrane at a position corresponding to the second through hole, and the diameter of the fourth through hole is larger than that of the second through hole; the fourth through hole is used to position and place the sample to be tested. The sealing gasket is sealed and connected to the side of the sample positioning membrane away from the reaction cell, and is configured as a flat plate structure made of transparent polymer material. The end plate is connected to the side of the sealing gasket away from the sample positioning film, and a fifth through hole is provided on its plate surface at the position corresponding to the fourth through hole. The fifth through hole constitutes a reaction observation hole.

6. The electrochemical in-situ reaction apparatus for time-resolved XAFS testing according to claim 3, characterized in that, Each of the aforementioned mounting positions includes a support plate extending from the outer wall of the first cylindrical end, a transmission nut, and a transmission nut fixing clip; a polygonal through hole is provided through the surface of the support plate, and the transmission nut is adapted to be installed in the polygonal through hole; the inner wall of the transmission nut is threadedly engaged with the transmission gear shaft; the transmission nut fixing clip is fitted onto the support plate from the side of the support plate, and includes two clamping plates opposite to the two side surfaces of the support plate, each of the two clamping plates having a sixth through hole at a position corresponding to the polygonal through hole, the diameter of the sixth through hole being larger than the outer diameter of the transmission gear shaft and smaller than the diameter of the circumscribed circle of the transmission nut; the transmission nut is confined within the polygonal through hole by the transmission nut fixing clip; When the transmission gear shaft rotates, the transmission nut, via the transmission nut fixing clamp, drives the visible part to reciprocate within the adjustment cavity along the axial direction of the transmission gear shaft.

7. The electrochemical in-situ reaction apparatus for time-resolved XAFS testing according to claim 3, characterized in that, The liquid layer thickness adjustment mechanism includes two sets of symmetrically arranged gear transmission pairs, and the third connecting part is provided with two mounting positions corresponding to the end of the first cylinder.

8. The electrochemical in-situ reaction apparatus for time-resolved XAFS testing according to claim 1, characterized in that, It is configured as a three-electrode system, including a reference electrode, a counter electrode, and a working electrode; Define the first surface as the top surface of the reaction cell and the second surface as the bottom surface of the reaction cell. Then, two electrode mounting holes are provided on one side of the reaction cell, which are connected to the inside of the reaction cell. The two electrode mounting holes are used to seal and install the reference electrode and the counter electrode, respectively. The working electrode is led out by the end face sealing mechanism when the sample to be tested is installed.

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