Device for in-situ X-ray fine structure absorption spectrum in-situ test of rotating disc electrode

Abstract

The invention provides a device for carrying out in-situ X-ray fine structure absorption spectrum testing on a rotating disc electrode. The device comprises an upper cover, a polyether-ether-ketone film, a body, a T-shaped ring, a through hole bolt and a base which are connected in sequence. A plurality of open holes are formed in the body, so that a reference electrode and a counter electrode can be conveniently placed, and a liquid inlet and a liquid outlet are formed in the body. The device is suitable for fluorescence detection of an X-ray fine structure absorption spectrum, and the excellent X-ray transmission performance of the polyether-ether-ketone film meets the research requirements of an X-ray fine structure absorption spectrum fluorescence method. The device provided by the invention adopts the telescopic rotating disc electrode to increase the number of photons received by the detector in unit area, so that the signal-to-noise ratio of in-situ testing is improved. Through in-situ testing of the catalyst coated on the rotating disc electrode, the structure difference of the catalyst between a laboratory research system and an industrial system (such as a membrane electrode) can be researched.

Description

Technical Field

[0001] The invention relates to the field of small scientific experimental devices, in particular to a device for in-situ testing of an X-ray fine structure absorption spectrum of a rotating disk electrode. Background Art

[0002] The present invention relates to a device and method for evaluating catalysts for acidic proton exchange membrane fuel cells (PEMFCs), which is of great significance for developing high-activity, high-stability and resource-rich alternative catalysts for currently expensive and scarce platinum group metal catalysts. Membrane electrode (MEA) and rotating disk electrode (RDE) are key experimental devices in electrochemical research and play an important role in evaluating catalyst activity, but there are essential differences between the two in terms of function and application.

[0003] MEA is a composite structure, commonly used in fuel cells and electrolyzers, consisting of a solid polymer electrolyte membrane with catalysts coated on both sides. MEA can directly evaluate the true performance of catalysts in electrochemical reactions under conditions close to actual application conditions. In contrast, RDE is a standard laboratory tool, mainly used for the study of electrochemical processes in the liquid phase. It consists of a rotatable disk electrode that can control the fluid dynamics conditions in the solution to deeply study the electrochemical behavior of the catalyst.

[0004] In terms of catalyst activity evaluation, MEA and RDE are significantly different: (1) MEA is a full-cell system, with oxidation and reduction reactions on the anode and cathode sides, respectively, and catalytic activity and polarization curves can be observed; while RDE is a half-cell system, focusing mainly on the reaction activity of the anode or cathode. (2) MEA can provide a test environment closer to actual applications, including temperature, pressure and electrolyte conditions, which is suitable for studying the actual performance of catalysts; while RDE is more used to understand the basic electrochemical properties of catalysts, such as electron transfer rate and surface reaction kinetics, and is usually carried out under idealized experimental conditions.

[0005] Given that MEA operates in a complex and challenging environment, its test results are more reflective of the performance of the catalyst under actual conditions. The 5-50μm diffusion layer created by RDE makes the acquired data generally reflect the behavior of the catalyst under relatively ideal conditions. Therefore, relying solely on non-in situ characterization methods to observe the microstructure of the catalyst on the electrode cannot accurately reflect its changes under actual working conditions. Inferring the structure and performance of the catalyst in MEA directly based on RDE results may lead to inaccurate evaluation.

[0006] Therefore, the present invention provides an improved evaluation system, by simulating the actual working conditions (such as temperature, pressure and electrolyte concentration) in MEA under the RDE system, and establishing an evaluation system correction between RDE and MEA. The device can evaluate the basic electrochemical properties of the catalyst under idealized experimental conditions, and at the same time test under conditions close to actual application conditions, so as to more accurately predict the performance of the catalyst in equipment such as fuel cells or electrolyzers, filling the gap between experimental and industrial systems. Summary of the invention

[0007] The present invention aims at solving the problem that the conventional method for characterizing the catalyst on the RDE cannot accurately reflect the real structure of the catalyst during the reaction, and is used to solve the problem that the structure of the catalyst on the RDE cannot be characterized in real time.

[0008] In order to achieve the purpose of characterizing the electronic structure and local structure of the catalyst on the RDE in the experimental system in situ (using an electrochemical workstation to cause oxidation / reduction reaction on the RDE surface), and thus fill the gap between the experimental system and the industrial system.

[0009] The present invention is an X-ray fine structure absorption spectroscopy (fluorescence method) device for in-situ testing of a rotating disk electrode (RDE), in particular a structure testing device for catalysts on a rotating disk electrode (RDE) for electrochemical reactions such as OER and HER.

[0010] The device includes:

[0011] ontology;

[0012] The interior of the body is hollow and contains a rotating disk electrode;

[0013] The hollow part of the body can also be loaded with an aqueous solution of liquid electrolyte material;

[0014] A polyetheretherketone film is disposed at one end of the rotating disk electrode and fixed by an upper cover, which is provided with an incident window as an incident channel for X-rays; the upper cover is used to provide a closed environment for the reaction system to prevent leakage of the electrolyte solution;

[0015] A T-ring is placed at the other end of the body;

[0016] The upper part of the body is provided with three openings, one for placing the reference electrode and the other for placing the counter electrode, and the other for placing the electrolyte solution inlet; and the side of the body is also provided with a hole for placing the electrolyte solution outlet;

[0017] A base is arranged at the lower part of the body.

[0018] The T-ring is engaged with the internal thread of the middle opening of the main body through a thread, and the upper cover is fixed to one end of the main body through a hexagon socket screw and a polyetheretherketone film, and is in close contact with the main body.

[0019] The body is fixed on a horizontal test platform; a hollow square portion with chamfered edges is provided at the bottom of the body, serving as an interface for fixing the body and a base on the horizontal surface of the test platform.

[0020] The T-ring and the rotating disk electrode RDE are respectively in contact with the body and are located in the cavity formed by the hollow part of the body. A sealing ring is provided. The sealing ring is used to provide a closed environment for the other side of the body, and also ensures that the RDE can be fixed in the middle of the body.

[0021] The rotating disk electrode RDE provides a carrier for the platinum catalyst material. When the RDE device is tested by X-ray fine structure absorption spectroscopy (fluorescence), the base is used to support the RDE device to be placed stably on a horizontal surface.

[0022] The main body is a cylinder, and the hollow part in the middle is two cylinders with different diameters; the small diameter cylinder is used to place the RDE, and the large diameter cylinder is used as a place to place the sample and store the electrolyte solution (such as H 2 SO 4 HClO 4 , NaOH, etc.).

[0023] The openings on the upper part and the side of the main body are hollow cylinders with internal threads; the thread diameters of the hollow cylinders are consistent; the placement opening for placing the reference electrode and the cylindrical opening for the electrolyte outlet are symmetrically positioned; an O-ring groove is arranged at a position on the main body in contact with the upper cover, and the size of the O-ring groove is larger than the large-diameter cylinder in the main body and smaller than the diameter of the main body, so as to ensure that the electrolyte solution in the main body will not leak during testing.

[0024] The polyetheretherketone film is provided with 6 hexagonal screw openings; the opening positions of the hexagonal screw openings coincide with the openings of the 6 hexagonal screws provided on the body and the upper cover. The thickness of the polyetheretherketone film is 0.24mm, and the material used is polyetheretherketone (also known as PEEK), which is a material that can transmit X-rays and produces almost no background.

[0025] The upper cover is a circular ring with thickness, and the middle of the circular ring is a circular opening; the incident window is arranged at the center point of the circular opening of the upper cover.

[0026] The bottom of the T-ring is a thick ring with a hollow cylinder in the middle; the inner diameter of the ring is the same as the inner diameter of the hollow cylinder; the hollow parts of the two parts are connected; the T-ring is integrally processed and cast.

[0027] The rotating disk electrode consists of an electrode and a driver. The electrode is a disk made of stainless steel or glass; the driver is a device that can rotate the electrode, usually consisting of a motor, a rotor, and a magnetometer. The catalyst material is attached to the surface of the electrode and is evenly distributed through multiple drip coating and baking.

[0028] Furthermore, the body and the upper cover are detachable and connected by threads. An internal thread is arranged on the top of the body device for connection with the upper cover.

[0029] Furthermore, the main body is a cylinder with a diameter of 78 mm and a height of 32 mm, and is made of PEEK. The middle part is two hollow cylinders with different diameters. The large hollow cylinder has a diameter of 48 mm and a height of 12 mm, and the small hollow cylinder has a diameter of 19 mm and a height of 20 mm, and the two cylinders are connected to each other.

[0030] Furthermore, the liquid outlet on the body is the same as the placement port of the counter electrode, which is two connected hollow cylinders with threads inside. The diameter of the large hollow cylinder is 10mm, and the diameter of the small hollow cylinder is 6mm. The counter electrode and bolt of M10×P1.5 are used to seal the opening. The length of the bolt is 17mm, and the length of the threaded part is 11mm. The name of the bolt is a solid bolt.

[0031] Furthermore, the reference electrode placement port and the liquid inlet on the body are composed of two hollow cylinders with different diameters but connected to each other. The diameter of the large cylinder is 10mm, and the diameter of the small cylinder is 6mm. There are threads in the opening, which are sealed with bolts when not in use. The specification of the bolt is M10×P1.5. The length of the bolt is still 17mm, and the length of the threaded part is 11mm. The name of the bolt is a through-hole bolt.

[0032] Furthermore, the depth of the hollow square (with chamfers) on the body connected to the base is 15 mm (with the lowest plane of the body as a reference).

[0033] Furthermore, the inner diameter of the sealing ring is 55 mm, the outer diameter is 61 mm, and the depth of the ring opened on the main body for placing the rubber ring is 1.5 mm.

[0034] Furthermore, the outer diameter of the upper cover is the same as the diameter of the body, which is 78mm. The thickness of the upper cover is 3mm and the material is PEEK. The opening in the middle of the upper cover is not cylindrical, but truncated cone. The bottom diameter of the truncated cone is 54mm, and the top diameter is 48mm. The angle between the side of the hollow truncated cone and the plane of the upper cover is 45 degrees.

[0035] Furthermore, the thickness of the circular ring of the base of the T-ring is 2 mm, the height of the hollow cylinder in the middle is 18 mm, the inner diameter of the hollow cylinder is 16 mm, and the outer diameter is 19 mm.

[0036] Furthermore, the length of the base is 78mm and the width is 32mm. The distance between the center points of the two square support columns on the base is 30mm, and they are symmetrically distributed with the axis of symmetry on one side of the long axis of the base. The length is 10mm, the width is 8mm, and the chamfer radius is 2mm. The distance between the center of the axis and the long axis on the side closer to the base (the long axis is used as the reference line) is 13mm. The center points of the liquid inlet, liquid outlet, reference electrode placement hole and counter electrode placement hole on the main body are projected to the base on the same horizontal line, and the distance between the horizontal line and the reference line is 23.3mm.

[0037] The assembly steps of the rotating disk electrode (RDE) in-situ test device are as follows:

[0038] The rotating disk electrode (RDE) is placed in the through hole on the side of the body close to the upper cover, and completely occupies the through hole on this side to ensure that there is as little gap as possible. The body uses polyetheretherketone (PEEK) with excellent chemical stability, processability and electrical insulation as the main material, avoiding adverse effects while simplifying the device structure.

[0039] Place an O-ring (sealing ring) with an inner diameter of 55mm, an outer diameter of 61mm, and a wire diameter of 1.5mm into the O-ring opening on the side of the body close to the upper cover. The use of polymer soft materials can make the material fully elastic, and compared with rigid or hard materials, it can effectively avoid damage such as bending caused by operational errors.

[0040] A polymer film with excellent X-ray transmittance is used as the window, taking into account the transmission X-ray absorption spectrum, so that multiple experiments can be carried out with one device, eliminating the measurement errors caused by different samples.

[0041] The upper cover of the present invention covers the film, and the openings of the six M4 hexagon socket screws on the body, the film and the upper cover are completely aligned. This method of positioning by opening the device eliminates the misalignment phenomenon during the assembly process.

[0042] The present invention provides a device and method for in-situ X-ray fine structure absorption spectroscopy (fluorescence method) testing of a rotating disk electrode (RDE), which has the following beneficial effects:

[0043] (1) Through the structure of the incident light port and the output light port of the device, and the advantage of the Kapton / SPEEK film used, which has the advantage of good transmittance, a device can meet the research needs of X-ray absorption spectrum fluorescence method, simplify the experimental process, and eliminate the errors caused by different samples.

[0044] (2) Extruded O-ring seals are used to seal rigid components, and cold packaging is used throughout the entire process. The assembly process has loose environmental requirements, making it easy to conduct experiments at room temperature.

[0045] (3) The insertion depth of the counter electrode and the reference electrode can be adjusted according to the actual situation, which effectively reduces the electrode polarization caused by the liquid resistance and provides a guarantee for the accuracy of electrochemical in-situ measurement.

[0046] (4) Polyetheretherketone (PEEK) with high chemical and mechanical stability is used as the main material. It has excellent processability, hardness and electrical insulation, and can also take into account the corrosion of strong acids and alkalis, thus expanding the usable experimental system.

[0047] (5) By introducing the in-situ X-ray fluorescence method into the catalyst fine structure characterization test on the RDE, the real-time characterization test of the fine structure of the catalyst on the RDE during the reaction process was realized; the difference in activity evaluation between the experimental test system and the actual reaction process system was made up, and a basis was provided for the proposal of a correction scheme for the activity evaluation of fuel cells in the industrial system.

[0048] (6) After the test, the rotating disk electrode in-situ testing device of the present invention can be reused multiple times by disassembling, cleaning, replacing electrode materials, etc., which not only reduces the cost but also enhances the repeatability of the experiment. The various components of the device are modularly processed, and the processing dimensions can be adjusted according to actual conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0050] Figure 1 It is a working schematic diagram of the in-situ testing device of the present invention.

[0051] Figure 2 It is a structural schematic diagram of the in-situ testing device of the present invention.

[0052] Figure 3 This is a schematic diagram of the main structure of the upper cover of the in-situ testing device.

[0053] Figure 4 This is a schematic diagram of the main structure of the in-situ testing device.

[0054] Figure 5 It is a schematic diagram of the rear view structure of the in-situ test device body.

[0055] Figure 6 Schematic diagram of the side opening structure of the in-situ testing device body.

[0056] Figure 7This is a schematic diagram of the front structure of the through-hole bolt of the in-situ testing device.

[0057] Figure 8 It is a schematic diagram of the side structure of the through-hole bolt of the in-situ testing device.

[0058] Fig. 9 Schematic diagram of the main structure of the solid bolt of the in-situ testing device.

[0059] Fig.10 This is a schematic diagram of the front structure of the T-ring of the in-situ testing device.

[0060] Fig.11 This is a schematic diagram of the side structure of the T-ring of the in-situ testing device.

[0061] Fig.12 This is a schematic diagram of the reverse structure of the T-ring of the in-situ testing device.

[0062] Fig.13 This is a schematic diagram of the main structure of the base of the in-situ test device.

[0063] Fig.14 Assembly flow chart of the in-situ testing device.

[0064] Fig.15 This is the cyclic voltammogram of the Pt catalyst tested in the device.

[0065] Fig.16 The X-ray absorption spectrum of Pt-L obtained by the device is 3 Absorption edge diagram.

[0066] Original label description

[0067] 101 Top Cover

[0068] 1011 Hexagon socket screw threaded through hole on the upper cover

[0069] 1012 Arc circle on the inner side of the upper cover

[0070] 1013 Upper cover side

[0071] 102 polyetheretherketone film

[0072] 103 First sealing ring

[0073] 104 Rotating Disk Electrode (RDE)

[0074] 105 Third sealing ring

[0075] 106 Through hole bolt

[0076] 1060 Through-hole bolt body front

[0077] 1061 Through-hole bolt cover

[0078] 1062 Through-hole bolts have threaded parts

[0079] 1063 Through hole bolt through hole

[0080] 107 Solid Bolt

[0081] 1070 Solid Bolt Body Front

[0082] 1071 Solid Bolt Bolt Cover

[0083] 1072 solid bolts have threaded parts

[0084] 108 body

[0085] 1081 body opening for base connection

[0086] 1082 Opening for placing through-hole bolts

[0087] 1083 Opening for solid bolts

[0088] 10831 Large hollow cylinder with through hole for placing through hole bolts

[0089] 10832 Small hollow cylinder with through hole for placing through hole bolts

[0090] 1084 Hexagon socket screw threaded through hole on the body for connecting the upper cover

[0091] 1085 Rotating Disk Electrode (RDE) Placement Hole

[0092] 1086 body O-ring groove on the contact side of the upper cover

[0093] 1087 body with threaded through hole for hexagon socket screw on the T-ring contact side

[0094] 1088 body for T-ring nesting opening

[0095] 109 Second sealing ring

[0096] 110 T-ring

[0097] 1101 T-Ring Hollow Cylinder

[0098] 1102 Contact surface

[0099] 1103 Hexagon socket screw threaded through hole on T-ring

[0100] 1104T-ring and O-ring contact surface

[0101] 1105 T-ring bottom side

[0102] 111 Base

[0103] 1110 Front part of the base

[0104] 1111 Support rod DETAILED DESCRIPTION

[0105] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand the advantages and effects of the present invention from the contents described in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details of this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0106] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention; the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance. In addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0107] See also Figures 1 to 13 It should be noted that the illustrations provided in this embodiment are only for illustrating the basic concept of the present invention. Although the illustrations only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation, the form, quantity and proportion of each component in actual implementation may be changed arbitrarily, and the component layout may also be more complicated.

[0108] Example

[0109] See also Figures 1 to 13The present invention provides a rotating disk electrode in-situ X-ray fine structure (fluorescence method) testing device, the in-situ testing device comprising: an upper cover 101 connected to the in-situ testing device and a body, a polyetheretherketone film 102 which effectively transmits X-rays and does not generate background, a first sealing ring 103 which is engaged with an O-ring groove on the body, a rotating disk electrode (RDE) 104 which is a core component of the in-situ testing device (the rotating disk electrode 104 comprises a disk electrode in the middle and a driver for rotating the electrode; a platinum catalyst material is attached to the surface of the electrode and is evenly distributed by multiple drip coating and baking), a third sealing ring 105 which is a hollow cylindrical opening on the side of the body, a through-hole bolt 106 with a through-hole for placing a reference electrode or a counter electrode, a solid bolt 107 without a through-hole for sealing a liquid inlet and a liquid outlet, a body 108, a second sealing ring 109 placed inside the hollow cylinder of the body, a T-ring 110, and a base 111.

[0110] See also Figure 1 The in-situ test using X-ray fluorescence is different from the X-ray transmission method. When the X-ray fluorescence method is used for testing, the incident X-ray is absorbed by the catalyst on the RDE and the generated X-ray fluorescence is emitted to the side of the in-situ test device, while the detector is at the side with an angle of 20 to 90 degrees with the incident light.

[0111] See also Figure 2 and Figure 3 The upper cover 101 connected to the body is a circular ring structure, and the outer periphery of the circular ring is provided with six through holes 1011 of equal diameter and evenly distributed along the circular shape of the upper cover for M4 upper cover hexagon socket screws. There is an arc 1012 with a slope of 45° in the middle of the circular ring, and the outer ring is the upper cover side 1013. The width of the arc projection is 3mm and the thickness is 3mm.

[0112] See also Figure 2 , the polyetheretherketone film 102 , the center positions of the openings of the six hexagon socket screws on the film are 35 mm away from the center position of the film, and the positions of these six openings are consistent with the positions of the hexagon socket screw threaded through holes 1011 on the upper cover 101 .

[0113] See also Figure 2 , 4 5. The shape of the first sealing ring 103 corresponds to the shape of the O-ring groove 1086 on the side of the body that contacts the upper cover, and is placed in the O-ring groove 1086 on the side of the body that contacts the upper cover. The second sealing ring 109 corresponds to the T-ring 110 and the opening 1088 on the body 108 for the T-ring to be nested.

[0114] See also Figure 2, the rotating disk electrode (RDE) 104 is placed in the rotating disk electrode (RDE) placement hole 1085 set on the body 108. There are many brands of RDE to choose from, but since the length of the internal rotating disk electrode (RDE) placement hole 1085 of the body 108 of this experimental device and the diameter of the circle of the through hole are fixed, a suitable RDE under this specification is selected. The conventional RDE guide material is glassy carbon + platinum ring, and the outer jacket material is polytetrafluoroethylene (PTEF) and polyetheretherketone (PEEK).

[0115] The third sealing ring 105 corresponds to the through hole on the body 108 where the through-hole bolt is placed, and is located in the large hollow cylinder 10831 of the through hole where the through-hole bolt is placed.

[0116] See also Figure 7 and Figure 8 As shown in the figure, the through-hole bolt 106 includes a through-hole bolt body front 1060, a through-hole bolt bolt cover 1061, a through-hole bolt bolt threaded portion 1062, and a through-hole bolt through hole 1063. The through-hole bolt 106 is a bolt with a hollow cylinder inside and external threads. The hollow cylindrical portion is used to place the reference electrode and the counter electrode as a carrier for the two. The through-hole bolt 106 is coupled to the internal thread of the through-hole large hollow cylinder 10831 of the body 108 where the through-hole bolt is placed, and the third sealing ring 105 is squeezed by tightening the thread to achieve a sealing effect.

[0117] See also Fig. 9 The solid bolt 107 is a bolt with external threads, and the thread diameter, thread type, pitch, etc. of the bolt are completely consistent with the thread of the through-hole bolt 106. The only difference is that there is no through hole inside the solid bolt 107, because it does not need to be a carrier of the electrode, and only needs to close the through hole large hollow cylinder 10831 for placing the through-hole bolt. As shown in the figure, the solid bolt 107 specifically includes a solid bolt body front 1070, a solid bolt bolt cover 1071, and a solid bolt bolt threaded portion 1072.

[0118] See also Figure 4 and Figure 5 , Figure 6The material of the in-situ test device body 108 is polyetheretherketone (PEEK), which is the main carrier. The upper cover 101, the polyetheretherketone film 102, the first sealing ring 103 on the side of the body in contact with the upper cover, etc. are all connected to the body. The many openings or grooves on the body are the spaces set as the carrier. The opening 1081 of the body for base connection is connected to the base 111 to support the entire in-situ test device body 108. The opening 1082 for placing the through-hole bolt is to provide the space required for the electrode. The opening 1083 for placing the solid bolt provides a channel for feeding and discharging. The hexagon socket screw threaded through hole 1084 on the body for connecting the upper cover is exactly the same as the through hole 1011 of the M4 upper cover hexagon socket screw uniformly distributed in a circular shape on the upper cover and the through hole on the polyetheretherketone film 102. The hexagon socket screw connects the three together, so that the upper cover 101 and the polyetheretherketone film 102 connected to the body are tightly fitted with the in-situ test device body 108. The rotating disk electrode (RDE) placement hole 1085 is used as a placement channel for the rotating disk electrode (RDE) 104. The O-ring groove 1086 on the side of the body used for contacting the upper cover is used as a placement channel for the first sealing ring 103. The hexagon socket screw threaded through hole 1087 on the side of the body used for contacting the T-ring corresponds to the hexagon socket screw threaded through hole 1103 on the T-ring, and the hexagon socket screw passes through the openings of the two, thereby allowing the T-ring to be nested with the in-situ test device body 108. The body opening 1088 for T-ring nesting, the second sealing ring 109 inside the body and T-ring nesting opening, and the T-ring 110 are connected in sequence. Since the contact surface 1102 of the T-ring 110 and the body has an external thread and the body opening 1088 for T-ring 110 nesting has an internal thread, the threads of the two are engaged with each other and the hexagon socket screw acts to firmly fix the T-ring 110 on the in-situ test device body 108.

[0119] The second sealing ring 109 corresponds to the T-ring 110 and the opening 1088 of the body for the T-ring to be nested.

[0120] See also Figures 10 to 12 The T-ring 110 is a top hat structure, but the middle of the T-ring is a hollow structure, a T-ring hollow cylinder 1101, the top of the T-ring hollow cylinder 1101 is the contact surface 1104 between the T-ring and the O-ring, and the bottom is evenly distributed with 6 T-ring upper hexagon screw threaded through holes 1103, and the bottom figure is the bottom side 1105 of the T-ring. There are threads on the outer wall of the protruding cylinder at the top. The T-ring 110 plays the role of closing the opening 1088 of the body for the T-ring to be nested.

[0121] See also Fig.13The base 111 supports the entire in-situ test device, and two support columns thereon are embedded in the in-situ test device body 108. During the test, the base 111 is placed on a horizontal test platform.

[0122] As an example, the thickness of the upper cover 101 of the in-situ testing device may not be limited to 3 mm, but on the one hand, the material of the upper cover and on the other hand, the thickness of the upper cover need to be considered. The overall center of gravity offset brought about by the two will affect the structural stability of the entire in-situ testing device. Therefore, in order to make the overall center of gravity as low as possible and the cost of the material should not be too high and easy to process, PEEK material is selected. The bevel angle of the inner arc circle 1012 of the upper cover with a slope of 45° is selected to be 45°, but is not limited to 45°. The use of an arc design with a slope of 45° can make the polyetheretherketone film 102 fit tightly to the side where the in-situ testing device body 108 and the upper cover are connected as much as possible during the process of screwing in the screw.

[0123] As an example, the polyetheretherketone film 102 has a light transmittance of more than 60%, although the aluminum film also has a high X-ray transmittance. Compared with the traditional in-situ test device using thick aluminum film and titanium plate and other materials, the present invention uses a polymer film with good X-ray transmittance as a window, taking into account the transmission X-ray absorption spectrum research using low-energy X-rays (5-8keV), so that one device can perform multiple experiments, eliminating the measurement errors caused by different samples and simplifying the experimental process. At the same time, in order to ensure the airtightness during the experimental test, the thickness of the film cannot be too thin. In this example, the thickness can be but is not limited to 0.012mm.

[0124] As an example, the maximum diameter of the O-ring groove 1086 on the upper cover contact side of the body is 61 mm, but is not limited to 61 mm and cannot exceed 68 mm. An area for drilling holes for hexagon socket screws needs to be left on the in-situ test device body 108 .

[0125] As an example, the first sealing ring 103 is an O-ring with elastic deformation and recovery capabilities. The material is fluororubber. This material has excellent oil resistance, heat resistance and chemical corrosion resistance, and is suitable for sealing requirements in harsh environments such as high temperature, high pressure and high speed. However, the price of fluororubber is relatively high, so it can be selected but not limited to. Other materials such as nitrile rubber, chloroprene rubber, and butyl rubber can also be used as alternatives. The inner diameter or outer diameter of the sealing ring is 55mm, and the wall thickness is 2-4mm. The sealing ring sealing method is adopted, and the whole process is cold packaged. There is no need to heat and melt the polymer material for sealing. The sealing performance is good and will not cause damage to the in-situ test device. The sealing ring in the present invention can select the above-mentioned O-ring.

[0126] See also Figures 4 to 6The material of the in-situ testing device body 108 can be but is not limited to polyetheretherketone (PEEK), and its size varies according to actual needs.

[0127] Preferably, in this embodiment, the main body of the in-situ test device is a cylinder with a diameter of 78 mm and a height of 32 mm. The shape and size of the O-ring groove 1086 on the upper cover contact side of the body corresponds to the shape and size of the first sealing ring 103 on the upper cover contact side of the body.

[0128] Preferably, in this embodiment, the inner diameter of the O-ring groove 1086 on the contact side of the upper cover of the body is 55mm, the outer diameter is 61mm, and the depth is 1.5mm. The outer diameter of the inner teeth of the large through-hole hollow cylinder 10831 for placing through-hole bolts is 10mm, and the height is 11mm. The diameter of the small through-hole hollow cylinder 10832 for placing through-hole bolts is 6mm, and the height is 4mm, which corresponds to the third sealing ring 105 of the side opening of the body. The outer diameter of the third sealing ring 105 is 6mm, the inner diameter is 4mm, and the wire diameter is 1mm. The opening 1088 of the body for T-ring nesting corresponds to the second sealing ring 109 inside the body and the T-ring nesting opening. The diameter of the opening 1088 of the body for T-ring nesting is 19mm, and the height is 16mm. The outer diameter of the second sealing ring 109 is 19mm, and the wire diameter is 1mm. The hexagon socket screw threaded through hole 1011 passing through the upper cover, the hexagon socket screw threaded through hole on the polyetheretherketone film 102, and the hexagon socket screw threaded through hole 1084 on the main body for connecting the upper cover correspond to each other.

[0129] Preferably, the hexagon socket screw threaded through holes 1084 on the six bodies for connecting the upper cover are evenly distributed on a circumference of 70 mm along the center diameter of the same horizontal plane from the in-situ testing device body 108 .

[0130] The hexagon socket screw threaded through hole 1087 on the T-ring contact side of the body is located on a circle with a center diameter of 30 mm on the same horizontal plane as the in-situ testing device body 108.

[0131] The in-situ test device body 108 uses polyetheretherketone (PEEK) with excellent chemical stability, processability and electrical insulation as the main material, avoiding the adverse effects caused by metal structures or polymer soft materials as the device body while simplifying the device structure.

[0132] The openings for placing through-hole bolts and the openings for placing solid bolts adopt a double-layer through-hole design, which can prevent leakage of electrolyte solution and play a positioning role.

[0133] As an example, the electrode lead wire used by the rotating disk electrode (RDE) 104 can be but not limited to copper wire, and the size of the electrode lead wire is selected according to actual needs. Preferably, in this embodiment, the electrode lead wire has a diameter of 0.4 mm and a length of about 100 mm.

[0134] See also Figures 10 to 12 As an example, the hexagon socket screw threaded through hole 1103 on the T-ring corresponds to the hexagon socket screw threaded through hole 1087 on the body for the T-ring contact side. The number of threaded through holes is 4, using M4 hexagon socket screws, the thread length is 10mm, and the depth of the hexagon socket screw threaded through hole 1087 on the body for the T-ring contact side is 6mm. Preferably, the thread embedding depth can be but is not limited to 6mm. There are external threads on the contact surface 1102, which correspond to the internal threads on the inner wall of the opening 1088 of the body for the T-ring nesting, so that the two can be tightly nested together.

[0135] See also Fig.13 , the support rod 1111 is arranged on the front part 1110 of the base. As an example, the length of the base 111 is 90mm, the width is 30mm, and the height is 10mm. The height of the support rod 1111 connecting the base and the body is 15mm, the length is 10mm, the width is 8mm, and there are chamfers all around, and the chamfer specification is 4×R2. The support rod 1111 is arranged on the front part of the base, and the center distance between the two support rods is 30mm. The center point of the support rod 1111 connecting the base and the body is projected onto the plane of the base, and the value of the point projected on the plane of the base is 13mm from the longer side of the base. Similarly, the opening 1081 of the body for base connection is projected onto the base, and the distance of the central axis of the figure projected onto the plane of the base (along the long side direction of the base) from the longer side of the base (consistent with the above-mentioned long side) is 23.3mm. The support rod 1111 connecting the base and the body corresponds to the opening 1081 of the body for base connection. Preferably, the base material in this embodiment may be but is not limited to polyetheretherketone (PEEK).

[0136] In addition, the present invention provides an assembly method for a rotating disk electrode in-situ testing device. For assembly steps, please refer to Fig.14 , the installation and removal steps are as follows:

[0137] Place the first sealing ring 103 inside the corresponding groove on the body.

[0138] Use 6 hexagonal screws to pass through the upper cover, the film and into the main body, and tighten the screws to the bottom to ensure that the upper cover and the film are in close and sealed contact with one side of the main body under the action of the screws.

[0139] An O-ring (second sealing ring 109) with an inner diameter of 16 mm, an outer diameter of 19 mm, and a wire diameter of 2 mm is placed in the opening on the back of the body where the body contacts the T-ring.

[0140] The T-ring is squeezed so that it completely occupies the opening on the side of the body and its nesting, and the protruding part of the rotating disk electrode is just embedded in the hollow through hole of the T-ring. Then, four hexagon socket screws are passed through the T-ring and enter the four hexagon socket screw threaded through holes on the body. Tighten these four screws, and the O-ring (second sealing ring 109) is squeezed by the external force of the screws continuously screwing in, so that the opening on the side of the body that contacts the T-ring is sealed.

[0141] Four small O-rings (third sealing ring 105) are placed in the four openings on the side of the body, and the reference electrode (RE) and the counter electrode (CE) are placed in the corresponding openings. The electrolyte solution is poured into the remaining hollow part inside the body through the liquid inlet. The corresponding through-hole bolts are screwed into the corresponding openings, and the O-rings achieve a sealing effect under the extrusion effect.

[0142] Place the assembled main body parts on the base. There are two square openings at the bottom of the main body. Insert the two support columns on the base into the openings at the bottom of the main body to complete the assembly process of the rotating disk electrode in-situ test device.

[0143] As an example, the rotating disk electrode in-situ testing device of the present invention can be applied to in-situ testing experiments of catalyst materials on RDE, and can also be used for other electrochemical reaction tests, such as oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER). Figure 1 As shown, the test steps can be:

[0144] 1. Apply a little phosphor around the 1mm diameter hole (PEEK film) at the light entrance center of the test device to facilitate the adjustment of the optical axis;

[0145] 2. The test device is introduced into the test cavity through the transmission rod mechanism, with the light entrance facing the direction of the X-ray. The position of the in-situ test device is adjusted to make the optical axis pass through the light entrance hole, and the experiment begins;

[0146] 3. Connect the electrochemical workstation and start CV (cyclic voltammetry) and LSV (linear sweep voltammetry) tests. The results of the cyclic voltammetry diagram are as follows: Fig.15 shown.

[0147] 4. Cyclic voltammetry is used to determine the working state of the battery to ensure that the battery is tested under a stable working state;

[0148] 5. Linear voltammetry: the time variation of current at a fixed potential (entering steady state);

[0149] 6. Select appropriate exposure time and incident angle to collect data; Pt-L X-ray absorption spectrum 3 Absorbing edge, such as Fig.16 shown.

[0150] 7. Turn off the light source and close the linear voltammeter.

[0151] After the test process is completed, first unscrew the through-hole bolts of the liquid outlet to discharge the electrolyte solution filled in the hollow part of the body. Then remove other components in order from top to bottom and from outside to inside.

[0152] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. An X-ray fine structure absorption spectrometer for in-situ testing of a rotating disk electrode, characterized in that: The device includes: ontology; The interior of the body is hollow and contains a rotating disk electrode; The hollow part of the body can also be loaded with an aqueous solution of liquid electrolyte material; A polyetheretherketone film is disposed at one end of the rotating disk electrode and fixed by an upper cover, wherein the upper cover is provided with an incident window as an incident channel for X-rays; the upper cover is used to provide a closed environment for the reaction system to prevent leakage of the electrolyte solution; Place a T-ring at the other end of the body; The upper part of the body is provided with three openings, one for placing the reference electrode and the other for placing the counter electrode, and the other for placing the electrolyte solution inlet; and the side of the body is also provided with a hole for placing the electrolyte solution outlet; A base is arranged at the lower part of the body.

2. The X-ray fine structure absorption spectrometer for in-situ testing of a rotating disk electrode according to claim 1, characterized in that: The T-ring is engaged with the internal thread of the middle opening of the main body through a thread, and the upper cover is fixed to one end of the main body through a hexagon socket screw and a polyetheretherketone film, and is in close contact with the main body.

3. The X-ray fine structure absorption spectrometer for in-situ testing of a rotating disk electrode according to claim 1, characterized in that: The body is fixed on a horizontal test platform; a hollow square part with chamfered edges is provided at the bottom of the body, serving as an interface for fixing the body and a base on the test bench; an O-ring groove is provided at a position on the body in contact with the upper cover, and the size of the O-ring groove is larger than the large-diameter column in the body and smaller than the diameter of the body.

4. The X-ray fine structure absorption spectrometer for in-situ testing of a rotating disk electrode according to claim 1, characterized in that: The T-ring and the rotating disk electrode RDE are respectively in contact with the body and are located in the cavity formed by the hollow part in the body, and are both provided with sealing rings.

5. The X-ray fine structure absorption spectrometer for in-situ testing of a rotating disk electrode according to claim 1, characterized in that: The main body is a cylinder, and the hollow part in the middle is two cylinders with different diameters; the small-diameter cylinder is used to place the rotating disk electrode RDE, and the large-diameter cylinder is used as a place to place samples and store electrolyte solutions.

6. The X-ray fine structure absorption spectrometer for in-situ testing of a rotating disk electrode according to claim 1, characterized in that: The openings on the upper part and the side of the body are cylindrical openings and have internal threads; the thread diameters of the cylindrical openings are consistent; The cylindrical opening for placing the reference electrode and the outlet of the electrolyte are symmetrically positioned; In the cylindrical opening, the liquid outlet on the body and the placement port of the counter electrode are the same, which are two connected hollow cylinders with threads inside; the diameter of the large hollow cylinder is 10mm, and the diameter of the small hollow cylinder is 6mm; the counter electrode and bolt of M10×P1.5 are used to seal the opening; the length of the bolt is 17mm, and the length of the threaded part is 11mm; the bolt is a solid bolt; The placement port and liquid inlet of the reference electrode on the main body are composed of two hollow cylinders with different diameters but connected to each other; the diameter of the large cylinder is 10mm, and the diameter of the small cylinder is 6mm; there is a thread in the opening, which is sealed with a bolt when not in use; the specification of the bolt is M10×P1.5; the length of the bolt is still 17mm, and the length of the threaded part is 11mm. The bolt is a through-hole bolt, and a sealing ring can be set when the cylindrical opening and the through-hole bolt are used.

7. The X-ray fine structure absorption spectrometer for in-situ testing of a rotating disk electrode according to claim 1, characterized in that: The polyetheretherketone film is provided with 6 hexagonal screw openings; the opening positions of the hexagonal screw openings coincide with the openings of the 6 hexagonal screws provided on the body and the upper cover; The thickness of the polyetheretherketone film is 0.24 mm.

8. The X-ray fine structure absorption spectrometer for in-situ testing of a rotating disk electrode according to claim 1, characterized in that: The upper cover is a circular ring with thickness, and the middle of the circular ring is a circular opening; the incident window is arranged at the center point of the circular opening of the upper cover.

9. The X-ray fine structure absorption spectrometer for in-situ testing of a rotating disk electrode according to claim 1, characterized in that: The bottom of the T-ring is a thick ring with a hollow cylinder in the middle; the inner diameter of the ring is the same as the inner diameter of the hollow cylinder; the hollow parts of the two parts are connected; the T-ring is integrally processed and cast.

10. The X-ray fine structure absorption spectrometer for in-situ testing of a rotating disk electrode according to claim 1, characterized in that: The rotating disk electrode includes a central disk electrode and a driver for rotating the electrode; Platinum catalyst material is attached to the surface of the electrode and is evenly distributed through multiple drip coating and baking.

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