Thermal chemical reaction tank suitable for X-ray transmission in-situ analysis

Abstract

The invention relates to the field of thermochemical in-situ reaction, and discloses a thermochemical reaction tank suitable for X-ray transmission in-situ analysis, which comprises a reaction generation module and a base support module, the reaction generation module comprises a reaction tube, a thermocouple, a heating resistance wire and a temperature control device. According to the invention, X-ray transmission-type analysis can be realized, and related structural characteristic changes of the material in a working process in a high-temperature and high-pressure environment can be accurately obtained; the device has a high altitude level time resolution, and has advantages for capturing an intermediate process highly dependent on time in a reaction process; the reaction tank is not limited by reaction gas selection and has a large-temperature-range heating function, so that the reaction tank can meet complex in-situ reaction experiment conditions; the method is high in characterization expansibility, can be combined with a mass spectrometer or a spatial resolution capillary sampling mass spectrometer for use, and simultaneously monitors product dynamic information in a reaction process; the device is small in size, easy to disassemble and convenient to replace to different instrument platforms for working; the device is simple in overall structure, low in manufacturing cost and beneficial to application and popularization.

Description

Technical Field

[0001] The present application relates to the field of thermochemical in-situ reactions, and specifically to a thermochemical reaction cell suitable for X-ray transmission in-situ analysis. The present invention is suitable for docking thermochemical reaction scenarios with a variety of transmission X-ray analyses, including diffraction spectra and absorption spectra, and provides analysis options for coupling online atmospheric pressure (0.01-1MPa) to high pressure (1-20MPa) mass spectrometry. It is suitable for facilities such as commercial transmission X-ray diffractometers or synchrotron radiation sources, and can dynamically capture the structural changes and reaction product information of catalysts in a wide range of reaction temperatures (room temperature to 1000°C) and diffraction angles (2θ≥0°) under in-situ reaction conditions, and is suitable for studying the working mechanism of complex catalysts in thermochemical in-situ reactions. Background Art

[0002] Studying the relationship between the structure and performance of catalysts under real reaction conditions is crucial to understanding the catalyst reaction mechanism, optimizing the catalyst design cost and improving the reaction efficiency. In situ characterization technology is a characterization method that strictly limits the material research object and the reaction environment. It is widely used because it can capture the dynamic structural changes of the catalyst during the reaction in real time. For the characterization of the bulk structure of the material research object during the reaction, the commonly used method is in situ X-ray analysis (In situ X-Ray Characterization). Reaction cells commonly used for in situ X-ray analysis and characterization are such as reflection reaction cells. Such reaction cells have in situ gas inlets and outlets and beryllium windows with high X-ray transmittance, and the sample stage is in the shape of a shallow crucible. After being emitted by the emitter, the X-rays pass through the beryllium window and irradiate the material object, and are received by the detector after reflection. The in situ gas inlet and the heating function of the sample stage can realize the changes in the bulk structure of the material object in the thermochemical reaction, and then obtain the intermediate state information of the reaction.

[0003] In the previous patent, the inventor achieved mass spectrometry collection and analysis of the reaction pool exhaust gas while the in-situ X-ray reaction pool was operating at variable temperature by custom-designing a metal capillary mass spectrometer sampling and a mass spectrometer analysis station solution for the reaction pool of the X-ray characterization equipment (ZL201710347554.2), and obtained kinetic information such as the conversion rate, yield and reaction rate of the reaction products together with the phase change information of the material object, thereby studying the relationship between the structure and performance of the catalyst under reaction conditions.

[0004] However, the existing in-situ X-ray reflection reaction cells still have limitations and cannot meet the research needs in some complex reaction environments. For example: ① Due to the fixed structure design of the sample stage of the reaction cell and the reflection diffraction mode of X-rays, the structural information of the material object obtained during the reaction is fixed at a fixed point, which cannot reflect the bulk structure change information of the catalyst at different sections. In addition, the diffraction signal is easily disturbed by the structure of the sample stage itself, which in turn affects the judgment of the reaction data. ② In order to obtain data with high signal-to-noise ratio and large-range scanning in the X-ray reflection diffraction mode, it is necessary to scan single steps. Long exposure time leads to low temporal resolution between diffraction data in a continuously heated working environment. Generally, a spectrum is obtained every few minutes. It is impossible to accurately associate the phase change information of the material object with the temperature change curve, which easily causes errors in data analysis. ③ The existing commercial in-situ X-ray reaction pool is hindered by the diffraction mode and heating function design. The internal space of the reaction pool is too large, and it has a large dead volume (about several hundred mL). Under the control of conventional flow rate (generally 5-20 standard milliliters per minute) gas, the large dead volume will dilute the reaction components, resulting in slow response of the characterization to the reaction changes. The in-situ X-ray online mass spectrometry characterization scheme integrates the functions of collective phase change and reaction kinetics analysis. It needs to synchronize the response time with the reaction-related changes such as temperature and gas to obtain information on the changes of active structures. However, the large dead volume of the reaction pool will affect information collection and time consistency. Summary of the invention

[0005] In view of the shortcomings of the above-mentioned existing in-situ X-ray characterization methods, in the present invention, the inventors have designed a thermochemical reaction pool suitable for the X-ray transmission mode. The reaction pool adopts a tubular microreactor structure. On the basis of maintaining the design premise of in-situ simulated working condition gas supply, the bulk structure information of the bed catalyst distributed on the tubular microreactor is obtained through the analysis mode of transmission X-rays. When there are strong X-ray light source conditions, such as liquid target light source or synchrotron radiation light source, X-ray laser light source, etc., compared with the reflection type, the transmission X-ray characterization can quickly obtain the real-time structural information of the material object at the corresponding temperature through the surface analyzer in a short time, achieve a shorter single spectrum acquisition time limit, and improve the time resolution of the in-situ characterization. For general laboratory X-ray light sources, although the use of transmission mode cannot improve the time resolution, it can also give play to the advantage of the tubular microreactor having more flexible simulation conditions. Therefore, the present invention is widely applicable to different X-ray generators. As a micro-reaction pool, firstly, the heating method it adopts can accurately and quickly change and control the temperature without affecting the transmission of X-rays; secondly, the micro-reaction pool structure of the present invention can be conveniently used in conjunction with other characterization instruments. For example, based on the inventor's previous patent (ZL201511003224.9), the reaction gas path control and mass spectrometer are connected to the head and tail sections of the tubular reactor, and the advantage of the small dead volume of the tubular reactor itself is used to realize the dynamic atmosphere control and reaction tail gas collection of the reaction process, and obtain the kinetic information of the reaction product in real time. Therefore, the results of the present invention can further realize the in-situ X-ray characterization technology for the bulk structure characterization of material objects at different positions in space, and reduce the delay of reaction tail gas collection by reducing the dead volume of the reactor, thereby improving the efficiency of obtaining reaction kinetic information. In addition, the present invention can also be used in conjunction with capillary spatially resolved sampling mass spectrometry, and with the expanded spatially resolved X-ray diffraction characterization, it can be used to reveal the dynamic behavior of catalysts under complex reaction conditions, improve the dynamic monitoring ability of existing characterization technology for materials, and provide a new research angle and idea for the characterization of many materials.

[0006] In view of the X-ray transmission and heating problems of the thermochemical reaction pool mentioned in the above technical background, in order to achieve the purpose of the invention, the present invention adopts the following technical solution, that is, a lightweight element tube with high transmittance to X-rays is used as a reactor, while ensuring that the X-rays can be transmitted normally, a resistance wire is used to heat the periphery of the reactor, and the fixed reaction section of the tubular reactor is flexibly and reliably heated without affecting the transmission of X-rays. At the same time, the inlet and outlet of the reaction tube at the front and rear ends are used to ensure the inlet and outlet of the reaction gas, so that the thermochemical reaction pool meets the requirements of real-time bulk structure information and reaction kinetics information collection, and then the complex research object, especially the bed catalyst, is dynamically monitored for the activity-related structural changes at different positions in the reaction. The present invention has the advantages of simple structure and low cost, and has strong scalability, and can be modified for various experimental needs, including but not limited to 1) replacing reactors of various diameters; 2) suitable for the installation of a spatially resolved mass spectrometer capillary sampling device. The present invention has good practical application prospects and provides a new technical solution for characterization tasks that are difficult to complete with traditional equipment.

[0007] The present invention has the following innovative advantages in view of the following problems:

[0008] 1. Transmission will inevitably lead to radiation absorption. X-ray transmittance is affected by the length and material of the material in the optical path. If there is too much absorption, the transmittance is low and the signal is small; if there is too little absorption, the transmittance is high, but there is little information related to the contained material. X-ray transmittance is also affected by the diameter and material of the tubular reactor that contains the material. The present invention optimizes the reaction tube to make the sample loading amount fully compatible with the X-ray transmission mode. By optimizing the material and diameter of the reaction tube, the X-ray transmission absorption is reasonably distributed to the loaded sample, generating a signal with a high signal-to-noise ratio.

[0009] Second, the scale of the X-ray incident spot should match the operating reaction tube. First, the spot size after X-ray incidence should match the inner diameter of the reaction tube to ensure that all light sources pass through the sample area. The reaction tube should retain windows for X-ray incidence in different sections of the sample. The present invention can retain multiple windows that are at least larger than the cross-section of the light source spot in different sections of the reaction tube to ensure a full range of structural analysis of the thermal reaction catalytic sample;

[0010] 3. The heating method can meet the temperature range required by the thermochemical reaction scenario and is compatible with the optical path requirements of X-ray transmission analysis as mentioned above 1 and 2. The optimized heating method of the present invention includes the material, wire diameter and structure of the heating wire, which can be evenly heated to 1000°C while meeting the X-ray transmission analysis in the full loading section;

[0011] Fourth, the thermocouple used to read and control the temperature negative feedback cannot affect the X-ray transmission or the reaction. The present invention adopts the installation scheme of co-heating thermocouple. The thermocouple and the reaction tube are in the same heating environment. After calibration, it can accurately reflect the real-time temperature of the reaction tube. At the same time, the thermocouple does not contact the internal space of the reaction tube and the sample, and does not affect the light path and the reaction at all.

[0012] 5. As a high-temperature thermochemical reaction tube for optical analysis in an open environment, a reasonable and safe assembly method is required. The support structure design adopted by the present invention ensures that the high-temperature tubular reactor of the thermochemical reaction pool maintains a safe distance from the surrounding working surface and the light source and detector;

[0013] 6. Realize the real-time connection between the high temperature and high pressure environment of the sampling point and the working environment of the mass spectrometer. The present invention can complete the direct sampling from the thermochemical reaction environment of 0.01MPa to 20MPa to the mass spectrometer working environment of 10-9-10-6MPa;

[0014] 7. Cost control: The present invention can reduce the cost of the overall material of the equipment and the necessary items in the experimental process to a controllable range through assembly with domestic general consumables.

[0015] In response to the above problems, the inventors directly transported the sampled fluid to the mass spectrometer for analysis based on the capillary sampling scheme of the prior patents (ZL201610140435.5, ZL201710094416.8, 202410220463.2). The relevant connection scheme can directly solve problem six. The sample is filled in a fixed bed section in a tubular reactor, and the inner diameter of the reaction tube is larger than the X-ray spot to achieve full X-ray transmission and enable transmission-type characterization at different positions. At the same time, the wall thickness and inner diameter of the reaction tube are optimized under the premise of considering the X-ray intensity, and the absorption of the sample and the tube wall is reasonably distributed. X-ray transmission has clear requirements on the transmittance and material strength of the reaction tube material of the tubular reactor, that is, the material: 1) is transparent to X-rays; 2) has the ability to withstand high temperature and high pressure; 3) does not participate in high temperature reactions. Point 1) requires that the material must be composed only of the first 13 elements of the periodic table, point 2) requires that the material be metal or generalized glass or generalized ceramic material, and point 3) excludes metal materials. The inventor used a tubular reactor of relevant materials to solve this problem. The materials that can be selected include but are not limited to carbon materials, boron nitride, aluminum oxide, etc. Under high pressure conditions, the material needs to be strengthened, such as boron nitride needs to be ceramicized, aluminum oxide needs to reach sapphire level, and so on. For example, the melting point of boron nitride is as high as 2700°C, which can withstand the normal operation of all chemical reactors at high temperatures. At the same time, the boron nitride material itself has good X-ray transmittance, which can ensure that more than 70% of the original strength can be retained after X-rays above 8KeV pass through the reaction tube (question one). After optimization, the tubular reactor belongs to a microreactor with a very small heat capacity. It can be heated to 1000°C in an air environment with less than 50W heating power (question three). Therefore, the external heating adopts a fixed pitch high-temperature resistance wire method, which not only ensures that the sample can be heated evenly, but also ensures that the X-ray can be normally transmitted between the pitches of each segment of the spiral (question two). In order to accurately detect the temperature at the X-ray diffraction characterization position, the ceramic tube encapsulated thermocouple is placed close to the tubular reactor, and the heating wire is directly wrapped tightly on the outer surface of the tubular reactor (Question 4). Other methods of integrating the thermocouple with the reaction tube can also be used to fix the thermocouple directly in contact with the hot surface of the reaction tube without contacting the catalyst and insulated from the heating wire. Adapter sleeves are used at both ends of the tubular reactor to connect the pipeline for in-situ reaction gas supply, and sealing rings are used to ensure the airtightness of the reactor, so that the air velocity and pressure under industrial in-situ conditions can be strictly simulated. The reaction tubes of the tubular reactor are fixed on the support frame and the base and other components to ensure the shockproof strength while reducing the thermal contact with the surrounding working surface. In order to achieve functional expansion, such as docking with different X-ray equipment, a large number of through holes and threaded holes are reserved on the base, and the support frame also has different customized sizes to facilitate installation in different spaces (Question 5).Finally, according to the design requirements, parts are purchased at an appropriate cost space and the assembly of the reaction pool is completed. All components can be assembled with domestic general consumables, ensuring quality requirements and cost control (Question 7). The reaction pool can fully realize the functions of in-situ X-ray transmission characterization technology, including the bulk phase characterization of the in-situ reaction process from room temperature to 1000°C, and X-ray transmission can reduce the exposure time required for a single spectrum acquisition during the heating process. The time resolution reaches the second level, which matches the time resolution of the online mass spectrometer. For example, the short-lived intermediate phase that appears in the catalyst sample during the heating process is fully captured, truly realizing the in-situ characterization of activity-related. The invented device can also be combined with a spatially resolved mass spectrometer capillary sampling device to analyze the reaction kinetics of the bed catalyst at different positions during the reaction process, providing a powerful characterization method for the reaction mechanism research of the catalyst.

[0016] Specifically, the present invention discloses the following technical solutions:

[0017] A thermochemical reaction cell suitable for X-ray transmission in-situ analysis, comprising a reaction generation module;

[0018] The reaction module comprises:

[0019] Reaction tube;

[0020] A thermocouple and a heating resistance wire, wherein the heating resistance wire is fixed to the outside of the reaction tube together with the thermocouple after the pitch of the heating resistance wire is predetermined by a mold and the shape is fixed;

[0021] Temperature control equipment.

[0022] Preferably, the reaction module further comprises a support platform;

[0023] The support platform comprises:

[0024] First bracket;

[0025] A second bracket is movably arranged relative to the first bracket.

[0026] Preferably, the thermochemical reaction tank further comprises a base support module;

[0027] The base support module comprises:

[0028] A base, on which the reaction module is arranged;

[0029] The adapter component is arranged at the bottom of the base and is used to transfer the base to the fixed installation position of the X-ray equipment optical path.

[0030] Preferably, a slide groove is provided on the base, and the second bracket is slidably disposed in the slide groove, and the second bracket can slide in a direction close to or away from the first bracket.

[0031] Preferably, in order to ensure that the X-rays can retain sufficient strength when they are transmitted until they reach the surface detector, the reaction tube adopts a ceramic boron nitride tube with an outer diameter of 5 mm, an inner diameter of 3 mm, and a length of 80 mm and high X-ray transmittance.

[0032] Preferably, a powder catalyst is filled in the reaction tube for testing and analysis.

[0033] Preferably, the catalyst powder is doped with boron nitride powder at a volume ratio of 1:49 when it is filled into the reactor to prevent excessive absorption of X-ray transmission caused by the sample. The powder is filled to the middle of the reaction tube, and gas paths are connected on both sides.

[0034] Preferably, the heating resistance wire is made of a 0.4 mm diameter iron-chromium-aluminum high-temperature alloy resistance wire. This specification of resistance wire can not only ensure good metal ductility, but also withstand the voltage and temperature required for the experiment, and can reach 1400° C. in the air.

[0035] Preferably, the pitch of the heating resistance wire after shaping is 1.20 mm, with a total of 20 turns and 24.00 mm. It is pre-shaped and installed on the reaction tube, and the two extended ends are connected to the temperature control device.

[0036] Preferably, the temperature control device is a general PID control power device, which uses a variable voltage alternating current for output and can change the output voltage according to different resistance wires and temperature requirements.

[0037] Preferably, the temperature controller linearly controls the heating rate and the target temperature by a PID program control method.

[0038] Preferably, the reaction tube and the gas pipeline are connected by a stainless steel conversion joint. When the reaction temperature is 1000° C., the temperature between the reaction tube and the stainless steel conversion joint is 100° C., and the O-ring is made of silicone.

[0039] Preferably, the air inlet and outlet pipes of the gas pipeline are made of 1 / 16 inch outer diameter copper pipes.

[0040] Preferably, an insulating ceramic tube for packaging is provided outside the thermocouple.

[0041] Preferably, the insulating ceramic tube is a double-hole ceramic tube with an outer diameter of 2 mm and an inner diameter of 0.6 mm*2, and the thermocouple junction is protected by a single-hole ceramic tube with an outer diameter of 2 mm and an inner diameter of 1 mm.

[0042] In the present invention, theoretically, any material with good X-ray transmittance can be used as the material of the reaction tube. However, since the reaction tube needs to be heated by a resistance wire, the following issues should be considered in actual use: 1. The physical properties of the material, such as high temperature heat resistance and electrical insulation; 2. The reaction tube material cannot affect the reaction characteristics of the material itself (such as metals themselves are prone to catalytic properties, which may affect the results of the catalytic reaction); 3. Whether the material itself meets the processing technology requirements (such as whether the material is easy to be plasticized into a hollow cylinder, and the minimum inner and outer diameters).

[0043] In the present invention, the fixation and airtightness between the reaction tube and the gas path are achieved by a high-pressure resistant joint and a sealing ring. In actual use, the upper temperature limit of the joint position can be determined according to the distance between the reducer and the thermal radiation heating resistance wire, and the material of the heat-resistant sealing ring can be selected.

[0044] In the present invention, the heating resistance wire should have good high temperature tolerance and ductility in air due to the working temperature requirements. According to different outer diameters of the reaction tubes and working temperature requirements, the resistance wires of different materials and cross-sectional diameters should be replaceable.

[0045] In summary, the device of the present invention has the following main advantages:

[0046] (1) It can realize X-ray transmission analysis and accurately obtain the structural characteristic changes of materials in the process of working in high temperature and high pressure environment;

[0047] (2) It has high temporal resolution, which is advantageous for capturing intermediate processes that are highly time-dependent during reactions;

[0048] (3) No restrictions on the choice of reaction gas and a wide temperature range heating function ensure that the reaction pool can meet the conditions of complex in-situ reaction experiments;

[0049] (4) The characterization is highly scalable and can be coupled with a mass spectrometer or a spatially resolved capillary sampling mass spectrometer to simultaneously monitor the product kinetic information of the reaction process;

[0050] (5) Small size, easy to disassemble, and convenient to replace on different instrument platforms for work;

[0051] (6) The overall structure of the device is simple and the manufacturing cost is low, which is conducive to popularization and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 : Thermochemical reaction cell for in-situ analysis of X-ray transmission in the embodiment of the present application;

[0053] Figure 2 : The front view of the reaction module in the embodiment of the present application;

[0054] Figure 3: A cross-sectional view of a reaction module in an embodiment of the present application;

[0055] Figure 4 : Independent temperature test diagram of the thermocouple moving 20 mm in the empty reactor tube when heated to 700°C. The red area in the figure represents the area where the thermocouple measures the ideal constant temperature, and the center line of the red area represents the center line position of the reactor tube.

[0056] Figure 5 : Real-time X-ray transmission diffraction data during the heating process from room temperature to 600°C. Different diffraction peak intensity labels represented by different color areas are presented on the right. The 2θ position of the horizontal axis in the figure is determined by the position of different diffraction rings and direct X-rays, and the coordinates of the Ga-In target are converted to Cu target coordinates by the Bragg diffraction law.

[0057] Figure numerals: 100, reaction module; 101, reaction tube; 102, heating resistance wire; 103, thermocouple; 104, insulating ceramic tube; 105, first bracket; 106, second bracket; 200, base support module; 201, adapter component; 202, base. DETAILED DESCRIPTION

[0058] The structure and effect of the present application are further described in detail below in conjunction with the embodiments. It is to be understood that the specific embodiments described herein are only used to explain the invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention rather than the entire structure are shown in the accompanying drawings.

[0059] like Figure 1 As shown, a thermochemical reaction cell for X-ray transmission is assembled. The material research object adopts a TiO2-Mn2O3-Na2WO4 / SiO2 catalyst system with an obvious phase transition at 650°C;

[0060] Preferably, an X-ray diffractometer using Ga-In liquid metal as a target is used, and the reaction module is installed on the instrument using an aluminum alloy column as a transition component to maintain the reaction module in the same plane as the X-ray to form vertical transmission.

[0061] Preferably, in order to ensure that the X-rays can maintain sufficient strength when they are transmitted until they reach the surface detector, the reaction tube adopts a ceramic boron nitride tube with high X-ray transmittance of 5 mm in outer diameter, 3 mm in inner diameter, and 80 mm in length;

[0062] Preferably, a powder catalyst is filled in the reaction tube for testing and analysis;

[0063] Preferably, the catalyst powder is doped with boron nitride powder at a volume ratio of 1:49 when it is filled into the reactor to prevent excessive absorption of X-ray transmission caused by the sample. The powder is filled to the middle of the reaction tube and gas paths are connected on both sides. The structural section is as follows: Figure 3 As shown;

[0064] Preferably, the heating resistance wire is made of a 0.4mm diameter iron-chromium-aluminum high-temperature alloy. This specification of resistance wire can ensure good metal ductility, withstand the voltage and temperature required for the experiment, and reach 1400°C in the air;

[0065] Preferably, the pitch of the heating resistance wire after shaping is 1.20 mm, with a total of 20 turns and 24.00 mm, and it is pre-shaped and installed on the reaction tube, and the two extension ends are connected to the temperature controller;

[0066] Preferably, the temperature controller is a general PID control power device, the output uses a transformer AC, and the output voltage can be changed according to different resistance wires and temperature requirements. In this embodiment, the transformer is set to a maximum output of 32 volts;

[0067] Preferably, the temperature controller linearly controls the heating rate and the target temperature by a PID program control method;

[0068] Preferably, the reaction tube and the gas pipeline are connected by a stainless steel conversion joint. When the reaction temperature is 1000°C, the temperature between the reaction tube and the stainless steel conversion joint is 100°C, and the O-ring is made of silicone.

[0069] Preferably, the air inlet and outlet pipes are made of 1 / 16 inch outer diameter copper pipes;

[0070] Preferably, the ceramic tube for encapsulating the thermocouple is a double-hole ceramic tube with an outer diameter of 2 mm and an inner diameter of 0.6 mm*2, and the thermocouple junction is protected by a single-hole ceramic tube with an outer diameter of 2 mm and an inner diameter of 1 mm.

[0071] Example

[0072] The present application discloses a thermochemical reaction cell suitable for X-ray transmission in-situ analysis. Figure 1 and Figure 2, which includes a base support module 200 and a reaction module 100. The base support module 200 plays the role of supporting and fixing the positions of the working parts relative to each other. The base support module 200 includes an adapter component 201 (such as two cylinders with the same length and both ends having external threads) and a long strip base 202 with a long rectangular slide and multiple threaded holes, both of which are made of high-strength materials such as aluminum alloy or stainless steel. One end of the adapter component 201 will be fixed on the mounting position provided on the optical path of the X-ray transmission equipment, and the other end will be fixed on the long strip base 202, so as to adjust the reaction module 100 to the state of being in the same plane with the X-ray and forming a transmission state. In order to adapt to different X-ray equipment (the height difference between the mounting position provided on the optical path of different instruments and the X-ray source is different), the reaction pool allows to be equipped with different customized adapter components 201 to adjust the height position of the reaction module 100.

[0073] The reaction module 100 is the core component of the thermochemical reaction pool, and is mainly composed of a reaction tube 101, a heating resistor 102, a thermocouple 103, an insulating ceramic tube 104 encapsulating the thermocouple 103, and a temperature control device. The support platform includes two supports, a first support 105 with only a fixed installation through hole, and a second support 106 with a slide groove distance adjustment design, which is suitable for reaction tubes 101 of different lengths. Specifically, a slide groove is provided on the base 202 of the base support module 200, and the second support 106 is slidably arranged in the slide groove, so that the second support 106 can slide in a direction close to or away from the first support 105 to adapt to the use of reaction tubes 101 of different lengths. An enlarged conceptual diagram of the reaction module 100 is shown in FIG. Figure 2As shown, the figure mainly shows the composition of the reaction module 100, and does not include a temperature control device. Among them, the second bracket 106 with a slide groove distance adjustment design in the bracket table is fixed on the side of the slide groove on the long strip base 202, and only the first bracket 105 with a fixed installation through hole is fixed on the other side. The reaction tube 101 is fixed on the bracket table. After fixing, the reaction tube 101 and the long strip base 202 maintain a horizontal and parallel relationship. The heating resistance wire 102 is pre-determined by the mold and shaped, and then fixed to the outside of the reaction tube 101 together with the thermocouple 103. The gap between the resistance wire pitch can ensure X-ray transmission and the normal operation of the heating and constant temperature functions of the reaction tube 101. In actual application, the reaction material object is filled into the reaction tube 101 and placed in the middle position, and the length of the filled material does not exceed the coverage length of the heating resistance wire 102, which is in a relatively constant temperature zone, and its temperature is absolutely consistent with the temperature measurement of the thermocouple 103. There are two ways to change the transmission position on the reaction tube 101 during the X-ray transmission characterization process: 1) the installation position provided by the X-ray transmission equipment has a displacement function, such as synchrotron radiation or liquid target diffractometers can be customized with related functions; 2) a linear displacement device is directly installed on the long strip base 202; both of the above methods can achieve continuous movement and remote control of the transmission point formed with the X-ray on the reaction tube 101.

[0074] In the embodiment, the powder filled in the reaction tube 101 with a length of 5 mm is physically mixed with TiO2-Mn2O3-Na2WO4 / SiO2 catalyst powder and boron nitride powder in a volume ratio of 1:49. Before the reaction, a separate thermocouple is moved in the empty tube of the reaction tube 101 to obtain independent test results of the heating temperature distribution at the filling section and before and after the filling section. Figure 4 The results show that the center of the heating zone of the embodiment is about 10 mm in an ideal constant temperature state, exceeding the catalytic material filling area. Figure 5 This is the phase change result of the in-situ heating reaction of the powder catalyst tested using a liquid target X-ray diffractometer. The two-dimensional surface detector was adjusted to detect a 2θ angle of 29 to 36°, spanning a total of 7°. When heating, the heating rate of the temperature controller was set to 10°C / min, and the single acquisition exposure time of the two-dimensional surface detector was 1min, thereby obtaining the phase change information of the catalyst powder during the heating process from room temperature to 600°C. Figure 3 It is clearly seen that the α-Cristo phase SiO2 in the bulk phase at room temperature undergoes a phase change when the temperature rises to about 200°C and transforms into β-Cristo. The cubic phase Na2WO4 in the bulk phase of the catalyst at room temperature weakens in intensity after 600°C, indicating that the transition to the orthorhombic phase begins (the complete phase transition temperature is 635°C). Although the detection angle of the two-dimensional surface detection in the embodiment is limited, the device of the present invention can obtain information on the intermediate phase transition that occurs in real time during the temperature change process of the catalyst.

[0075] The examples clearly show that the X-ray transmission thermochemical reaction cell of the present invention can obtain real-time phase change information of the bulk phase of the catalyst during temperature change, and can maintain a working state at high temperatures, and has stability and practicality.

[0076] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A thermochemical reaction cell suitable for X-ray transmission in-situ analysis, characterized in that: A reaction generation module is included; The reaction module comprises: Reaction tube; A thermocouple and a heating resistance wire, wherein the heating resistance wire is fixed to the outside of the reaction tube together with the thermocouple after the pitch of the heating resistance wire is predetermined by a mold and the shape is fixed; Temperature control equipment.

2. The thermochemical reaction cell suitable for X-ray transmission in-situ analysis according to claim 1, characterized in that: The reaction generation module also includes a support platform; The support platform comprises: First bracket; A second bracket is movably arranged relative to the first bracket.

3. The thermochemical reaction cell suitable for X-ray transmission in-situ analysis according to claim 1, characterized in that: The thermochemical reaction tank also includes a base support module; The base support module comprises: A base, on which the reaction module is arranged; The adapter component is arranged at the bottom of the base and is used to transfer the base to the fixed installation position of the X-ray equipment optical path.

4. The thermochemical reaction cell suitable for X-ray transmission in-situ analysis according to claim 3, characterized in that: The reaction generation module also includes a support platform; The support platform comprises: First bracket; a second bracket, the second bracket being movably arranged relative to the first bracket; The base is provided with a slide groove, and the second bracket is slidably arranged in the slide groove, and the second bracket can slide in a direction close to or away from the first bracket.

5. The thermochemical reaction cell suitable for X-ray transmission in-situ analysis according to claim 1, characterized in that: The reaction tube is a ceramic boron nitride tube with an outer diameter of 5 mm, an inner diameter of 3 mm, and a length of 80 mm and high X-ray transmittance.

6. The thermochemical reaction cell suitable for X-ray transmission in-situ analysis according to claim 1, characterized in that: The heating resistance wire is made of a 0.4mm diameter iron-chromium-aluminum high-temperature alloy resistance wire; The pitch of the heating resistance wire after shaping is 1.20 mm, with 20 turns in total.

7. The thermochemical reaction cell suitable for X-ray transmission in-situ analysis according to claim 1, characterized in that: The temperature control device is a general PID control power device, which uses variable voltage AC for output and can change the output voltage according to different resistance wires and temperature requirements; the temperature controller linearly controls the heating rate and target temperature through the PID program control method.

8. The thermochemical reaction cell suitable for X-ray transmission in-situ analysis according to claim 1, characterized in that: The reaction tube and the gas pipeline are connected by a stainless steel conversion joint; the gas inlet and outlet pipelines of the gas pipeline are made of 1 / 16 inch outer diameter copper tubes.

9. The thermochemical reaction cell suitable for X-ray transmission in-situ analysis according to claim 1, characterized in that: An insulating ceramic tube for packaging is arranged outside the thermocouple; the insulating ceramic tube adopts a double-hole ceramic tube with an outer diameter of 2mm and an inner diameter of 0.6mm*2, and the thermocouple junction is protected by a single-hole ceramic tube with an outer diameter of 2mm and an inner diameter of 1mm.

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