High-temperature in-situ mossfort spectrum reaction tank for thermocatalysis and application thereof

Abstract

The invention discloses a high-temperature in-situ mossfort spectrum reaction tank for thermocatalysis and application of the high-temperature in-situ mossfort spectrum reaction tank. The in-situ Mossbauer spectrum reaction tank can be perfectly matched with a Mossbauer spectrum instrument of a German Wissel company. The reaction tank is composed of a connector, an upper top cover, a heating rod, a sample holder, a tank body and a base. The two sides of the cell body are provided with an air inlet and an air outlet. Samples, heating assemblies and temperature measurement and control clinging clamping plates are placed on the clamping plates and the loading plates. Through holes are formed in the two sides of the tank body, and circulating cooling water is introduced, so that the temperature of the outside of the reaction tank is still close to the room temperature while the high-temperature reaction of the sample bin is ensured, and the safety of operators and a mossfort spectrometer is effectively protected. A gas outlet of the reaction tank can be connected with a steel pipe to be introduced into gas chromatography, so as to carry out in-situ online analysis on gas-phase products.

Description

Technical Field

[0001] The present application relates to a high-temperature in-situ Mössbauer spectroscopy reaction cell for thermal catalysis and its application, belonging to the field of advanced characterization techniques for thermochemical catalysis. Background Art

[0002] In the field of thermal catalysis, iron-based catalysts are widely used in various reactions such as Fischer-Tropsch synthesis and alkane aromatization. As the active component, iron species often undergo phase transitions during the reaction process. Precise measurement of the phase state and content changes is helpful for understanding the catalytic reaction process and the development of high-performance catalysts.

[0003] Utilizing the phenomenon of the nucleus emitting or resonantly absorbing γ-rays without recoil, the Mössbauer effect has been further developed to form an advanced catalyst characterization technique - Mössbauer spectroscopy. It has extremely high energy resolution and is extremely sensitive to Fe species, capable of quantitatively analyzing the phase state and specific content of iron species, and is an effective means for studying the hyperfine interactions in iron-based catalysts.

[0004] However, most current Mössbauer spectroscopy characterizations are limited to ex-situ tests before and after the reaction, and the dynamic evolution of some catalysts during the reaction process and the corresponding relationship between the catalyst structure and the product cannot be discovered in a timely manner. Therefore, it is crucial to develop a reaction cell for in-situ Mössbauer spectroscopy suitable for thermal catalysis. Summary of the Invention

[0005] The present application designs a novel high-temperature in-situ Mössbauer spectroscopy reaction cell for thermal catalysis, which is applicable to most atmospheric-pressure high-temperature thermal catalysis reactions involving Fe / Sn elements (including but not limited to carbon monoxide hydrogenation, carbon dioxide hydrogenation, carbon monoxide oxidation, etc.). It solves the problem of non-in-situ catalyst characterization and is beneficial for better understanding the dynamic evolution of the reaction catalyst during the reaction process.

[0006] In one aspect of the present application, there is provided a high-temperature in-situ Mössbauer spectroscopy reaction cell for thermal catalysis, and the high-temperature in-situ Mössbauer spectroscopy reaction cell includes a connector, a cover plate, a heating rod, a sample holder, a cell body, and a base;

[0007] The connector is a circuit integration interface, including but not limited to heating the sample, measuring and controlling the temperature, etc., and is placed on the cover plate;

[0008] From top to bottom, the cover plate, the heating rod, and the sample holder are connected as a whole for disassembling and replacing the sample;

[0009] The cell body is provided with a groove, integrating the functions of internal high-temperature in-situ reaction and external cooling to keep the outer shell close to room temperature. The heating rod and the sample holder are placed in the groove;

[0010] The side wall of the cell body is provided with a ray optical path for the ray to enter the groove;

[0011] From top to bottom, the cover plate, the cell body and the base are fixedly connected, and a sealed reaction space is formed between the cover plate and the groove;

[0012] The base serves as a support for the cell body to ensure that the sample in the groove is at the center of the ray irradiation.

[0013] Optionally, the cover plate is provided with a through hole I;

[0014] The upper end face of the cell body is provided with a coaxial blind hole I corresponding to the through hole I;

[0015] The inner sides of the through hole I and the blind hole I are both provided with threads, and the through hole I and the blind hole I are connected by a compression bolt;

[0016] A sealing ring I for sealing is provided between the cover plate and the upper end face of the cell body.

[0017] Optionally, the base is provided with a through hole II;

[0018] The lower end face of the cell body is provided with a coaxial blind hole II corresponding to the through hole II;

[0019] The inner sides of the through hole II and the blind hole II are both provided with threads, and the through hole II and the blind hole II are connected by a compression bolt;

[0020] A sealing ring II for sealing is provided between the base and the lower end face of the cell body.

[0021] Optionally, the lower end face of the cover plate integrally includes a heat insulation pad, a transition plate, the heating rod, and a thermocouple from top to bottom;

[0022] The thermocouple is attached to the sample holder;

[0023] The sample holder includes a loading plate and a clamping plate;

[0024] The loading plate is used to fix the sample. The loading plate is detachably fixed in the clamping plate. The loading plate is rotated to replace the sample, and after replacement, the loading plate is pushed into the clamping plate to fix the sample;

[0025] The electrical circuits of the heating rod and the thermocouple are integrated in the connector.

[0026] Optionally, the heating rod is cylindrical, and the power of the heating rod is 10 - 500 w;

[0027] The thermocouple includes a temperature - measuring thermocouple and a temperature - controlling thermocouple;

[0028] The type of the thermocouple is selected from at least one of type B, type R, type S, type N, type K, type E, type J, type T, and type C.

[0029] Optionally, coaxial through holes III are provided on the side wall I of the cell body and the side wall II corresponding to the side wall I;

[0030] From outside to inside, a pressing plate, a sealing ring, and a window are sequentially arranged, and together with the through hole III, they form the ray optical path;

[0031] The pressing plate is provided with a through hole IV, and coaxial blind holes III corresponding to the through hole IV are provided on the side wall I and the side wall II of the cell body. The through hole IV and the blind hole III are connected by a pressing bolt;

[0032] The material of the window is selected from at least one of plexiglass, ceramics, resin, and beryllium metal window.

[0033] Optionally, a through hole V is provided at the center of the side wall III of the cell body as the air inlet;

[0034] A through hole VI is provided at the center of the side wall IV of the cell body as the air outlet;

[0035] Both the through hole V and the through hole VI are provided with a connector I;

[0036] The diameter size of the connector I is selected from at least one of 3mm, 6mm, 8mm, and 10mm.

[0037] Optionally, through holes VII and through holes VIII are respectively further provided on the side wall III and the side wall IV of the cell body. Connectors II are provided at the through holes VII and through holes VIII as the channels for circulating cooling water, and each channel is connected to a liquid guiding pipe;

[0038] The connector II is connected to the liquid guiding pipe;

[0039] The diameter size of the connector II is selected from at least one of 3mm, 6mm, 8mm, and 10mm;

[0040] The diameter of the liquid guiding pipe is 0.1 - 50mm;

[0041] The material of the liquid guiding pipe is selected from at least one of polyvinyl chloride, polytetrafluoroethylene, silica gel, and rubber.

[0042] Optionally, the through hole VII is located around the through hole V on the side wall III and includes 4;

[0043] The through hole VIII is located around the through hole VI on the side wall IV and includes 4

[0044] Optionally, the high-temperature in-situ Mössbauer spectroscopy reaction cell for thermal catalysis includes a sealing ring and a sealing strip.

[0045] The sealing ring is selected from at least one of an O-ring, a U-ring, and a combined sealing ring.

[0046] Optionally, the cover plate, cell body, pressing plate, base, loading plate, clamping plate, heating rod, transition plate, etc. included in the high-temperature in-situ Mössbauer spectroscopy reaction cell for thermal catalysis are made of materials including but not limited to brass, stainless steel, other alloys, etc.

[0047] In another aspect of the present application, there is provided an application of the above-mentioned high-temperature in-situ Mössbauer spectroscopy reaction cell in a thermal catalysis reaction, and the thermal catalysis reaction is selected from at least one of hydrogenation of carbon monoxide, hydrogenation of carbon dioxide, and oxidation of carbon monoxide.

[0048] Optionally, in the thermal catalysis reaction, the gas introduced into the gas inlet is selected from at least one of hydrogen, carbon monoxide, carbon dioxide, and nitrogen.

[0049] The beneficial effects that the present application can produce include:

[0050] 1. The high-temperature in-situ Mössbauer spectroscopy reaction cell for thermal catalysis designed in the present application can obtain information on the dynamic evolution of the catalyst under in-situ reaction conditions, which helps to understand the mechanism of the catalytic reaction process and develop high-performance catalysts.

[0051] 2. The high-temperature in-situ Mössbauer spectroscopy reaction cell for thermal catalysis designed in the present application can be connected to a gas chromatograph at the rear end of the reaction cell to detect real-time gas products, which helps to explore the relationship between the structural evolution of the catalyst and the reaction performance.

[0052] 3. The high-temperature in-situ Mössbauer spectroscopy reaction cell for thermal catalysis designed in the present application is simple to operate and the components are modular. To replace the sample, only the upper top cover needs to be disassembled to take out the sample for replacement, reducing the contact time with the Mössbauer spectroscopy, so that the operator receives less radiation during the in-situ test. The cell body part does not need to be moved, ensuring that the position of each sample is the same every time and ensuring the unity of the characterization data.

[0053] 4. The high-temperature in-situ Mössbauer spectroscopy cell for thermal catalysis innovatively separates the reaction cell body from the sample chamber. Only by loosening the top nut can the sample chamber be taken out for sample replacement, reducing the contact time with the Mössbauer spectroscopy. The invention can obtain the true information of the catalyst under the reaction state and truly realize the combined analysis of the structure and performance of the catalyst. Currently, the reaction temperature for testing can range from 20°C to 700°C, and it is applicable to in-situ thermal catalysis tests under different reaction atmospheres at atmospheric pressure, including but not limited to Fischer-Tropsch synthesis, carbon dioxide methanation, carbon monoxide oxidation, reverse water gas shift, etc. It is applicable to multiple elements, including but not limited to Fe, Sn, etc. Description of the Drawings

[0054] Figure 1 It is a sectional design drawing of the in-situ Mössbauer reaction cell in Example 1.

[0055] Figure 2 It is a design drawing (front view) of the in-situ Mössbauer reaction cell in Example 1.

[0056] Figure 3 It is a design drawing (top view) of the in-situ Mössbauer reaction cell in Example 1.

[0057] Figure 4 It is a design drawing (side view) of the in-situ Mössbauer reaction cell in Example 1.

[0058] Figure 5 It is a 3D sectional design drawing of the in-situ Mössbauer reaction cell in Example 1.

[0059] Figure 6 It is a 3D overall design drawing of the in-situ Mössbauer reaction cell in Example 1.

[0060] Figure 7 It is a physical picture of the in-situ Mössbauer reaction cell in Example 1.

[0061] Wherein:

[0062] 1. Connector; 2. Cover plate; 3. Sealing ring; 4. Cell body; 5. Pressure plate; 6. Window; 7. Sealing ring; 8. Sealing ring; 9. Base; 10. Loading plate; 11. Clamping plate; 12. Heating rod; 13. Heat insulation pad; 14. Transition plate; 15. Heat insulation pad. Detailed Description of the Invention

[0063] The present application will be described in detail below in combination with the design and operation of the embodiments, but the present application is not limited to these embodiments. Any relevant practitioners who make structural adjustments equivalent to the embodiments without departing from any of the claims stated in this design belong to the scope of the technical solution.

[0064] Example 1

[0065] Design and Application of a High-Temperature In-Situ Mössbauer Reaction Cell for Carbon Monoxide Hydrogenation Testing Conditions

[0066] According to Figure 1-6 the design scheme, a high-temperature in-situ Mössbauer reaction cell for thermal catalysis is designed. The reaction cell includes components: connector 1, cover plate 2, heating rod 12, sample holder, cell body 4 and base 9. The physical picture is as Figure 7 shown. After testing, the highest reaction temperature of the reaction cell can reach 700 °C. After passing through cooling water, it can operate stably and keep the temperature of the outer shell close to 30 °C, effectively protecting the safety of the operator and the stable operation of the Mössbauer device.

[0067] The specific design method is as follows:

[0068] 1. Connector 1: Connector 1 is a circuit integration interface, used for connecting to an external temperature control box. It can control the heating rod 12 to increase the temperature and monitor the real-time temperature of the sample rack. Connector 1 is fixed on the cover plate 2.

[0069] 2. Cover plate 2, heating rod 12, sample rack (clamping plate 11, loading plate 10): The cover plate is made of brass, and the heating rod 12 and the sample rack (clamping plate 11, loading plate 10) are connected to the lower end. The heating rod 12 is commercially purchased with a power of 50W. The sample rack is made of brass and is divided into a clamping plate 11 and a loading plate 10. The sample is made into a round piece with a diameter of 13mm and placed in the loading plate 10. The loading plate 10 is rotated to fix the sample in the clamping plate 11. The thermocouples used for temperature measurement and control are all K-type thermocouples, which are closely attached to the sample rack, and the electrical circuits are integrated in Connector 1. The lower end face of the cover plate 2 integrally integrates a heat insulation pad 15, a transition plate 14, and a heat insulation pad 13 from top to bottom.

[0070] 3. Cell body 4: The cell body 4 is entirely made of brass and has a groove inside. When sealed with the cover plate 2, it forms a closed space for catalytic reaction and is used for in-situ reaction. A sealing ring 3 is provided between the upper end faces of the cover plate 2 and the cell body. Through holes are opened in the front and back of the cell body, and a window 6, a sealing ring 7, and a pressing plate 5 are successively provided. The pressing plate 5 is also made of brass. The pressing plate 5 has a through hole, and a coaxial blind hole is opened at the corresponding position on the cell body 4. The through holes are connected by a compression bolt. The window material is selected as organic glass with moderate hardness and high ray transmission efficiency. On both sides of the cell body 4, see Figure 4 , there are central through holes. At both ends of the central through holes, 3mm steel pipe connection nuts are provided for use as the air inlet and outlet. Central through holes are also provided around the cell body. At both ends of the peripheral through holes, 8mm liquid guide pipe connection nuts are provided for connecting the coolant. The coolant is circulated and supplied by a common commercial chiller, and the set temperature is generally 20°C to ensure that the temperature of the outer shell of the cell body 4 is not high during operation.

[0071] 4. Base 9: The base 9 is made of brass and has a through hole. A corresponding coaxial blind hole is provided at the lower end of the corresponding cell body 4. The inner sides of the through hole and the blind hole have threads, and the holes are connected by a compression bolt. A sealing ring 8 for sealing is provided between the base 9 and the lower end of the cell body 4 to ensure airtightness. The height dimension of the base 9 is adapted to the Mössbauer spectrometer of the German wissel company, so that the window position is flush with the height of the central ray.

[0072] Test example

[0073] Taking the test conditions of carbon monoxide hydrogenation as an example, using the high-temperature in-situ Mössbauer spectroscopy reaction cell obtained in Example 1, the specific operation steps are as follows:

[0074] 1. Experimental preparation stage: Connect the base 9 tightly to the cell body 4 through the sealing ring 8 and the compression bolt. Fix the assembled cell body in the Mössbauer instrument, connect the steel pipes at the air inlet and outlet, connect the liquid guide pipe to the cell body, and connect the liquid guide pipe to the chiller. Place the sealing ring 3 on the upper end of the cell body 4 first.

[0075] 2. Sample loading stage: Make the sample into a 13-mm round slice, put it into the loading plate 12, and rotate the loading plate 12 to fix the sample in the clamping plate 11. Assemble the upper cover plate 2 and the sample holder onto the cell body 4 and tighten the compression bolt.

[0076] 3. Reaction start stage: Connect the circuit of the external temperature control box to the connector 1, introduce the reaction gas (carbon monoxide plus hydrogen), use the hydrogen alarm to check whether there is air leakage at the interface. After the inspection, introduce cooling water, turn on the temperature controller, raise the temperature programatically, and collect the corresponding Mössbauer spectrum test signals at the same time.

[0077] 4. Sample replacement stage: After the previous reaction ends, turn off the gas supply, unplug the connector, loosen the compression bolt at the upper end of the upper cover 2 and the cell body 4, and remove the upper cover 2. Rotate the loading plate 12, take out the reacted sample, replace it with a new sample, and then repeat the operations in the sample loading stage and the reaction start stage.

[0078] The above are only several embodiments of the present application, and do not impose any form of limitation on the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art, without departing from the scope of the technical solution of the present application, makes some changes or modifications using the technical content disclosed above, which are equivalent to equivalent implementation cases and all fall within the scope of the technical solution.

Claims

1. A high-temperature in-situ Mössbauer spectroscopy reaction cell, characterized in that, The high-temperature in-situ Mössbauer spectroscopy reaction cell includes a connector, a cover plate, a heating rod, a sample holder, a cell body, and a base; The connector is a circuit integration interface and is placed on the cover plate; From top to bottom, the cover plate, the heating rod, and the sample holder are connected as a whole; A groove is provided in the cell body, integrating the functions of internal high-temperature in-situ reaction and external cooling to keep the outer shell close to room temperature. The heating rod and the sample holder are placed in the groove; A ray optical path is provided on the side wall of the cell body to allow the ray to enter the groove; From top to bottom, the cover plate, the cell body, and the base are fixedly connected, and a sealed reaction space is formed between the cover plate and the groove; The base serves as a support for the cell body to ensure that the sample in the groove is at the center of the ray irradiation; 2. The high-temperature in-situ Mössbauer spectroscopy reaction cell according to claim 1, characterized in that, The cover plate is provided with a through hole I; The upper end surface of the cell body is provided with a coaxial blind hole I corresponding to the through hole I; Threads are provided on the inner sides of the through hole I and the blind hole I, and the through hole I and the blind hole I are connected by a compression bolt; A sealing ring I for sealing is provided between the cover plate and the upper end surface of the cell body; 3. The high-temperature in-situ Mössbauer spectroscopy reaction cell according to claim 1, characterized in that, The base is provided with a through hole II; The lower end surface of the cell body is provided with a coaxial blind hole II corresponding to the through hole II; Threads are provided on the inner sides of the through hole II and the blind hole II, and the through hole II and the blind hole II are connected by a compression bolt; A sealing ring II for sealing is provided between the base and the lower end surface of the cell body; 4. The high-temperature in-situ Mössbauer spectroscopy reaction cell according to claim 1, characterized in that, The lower end surface of the cover plate integrally integrates a heat insulation pad, a transition plate, the heating rod, and a thermocouple from top to bottom; The thermocouple is attached to the sample holder; The sample holder includes a loading plate and a clamping plate; The loading plate is used to fix the sample, and the loading plate is detachably fixed in the clamping plate; The electrical circuits of the heating rod and the thermocouple are integrated in the connector; 5. The high-temperature in-situ Mössbauer spectroscopy reaction cell according to claim 4, characterized in that, The heating rod is cylindrical, and the power of the heating rod is 10 - 500 w; The thermocouple includes a temperature-measuring thermocouple and a temperature-controlling thermocouple; The type of the thermocouple is selected from at least one of B type, R type, S type, N type, K type, E type, J type, T type, and C type; 6. The high-temperature in-situ Mössbauer spectroscopy reaction cell according to claim 1, characterized in that, Coaxial through holes III are provided on the side wall I of the cell body and the side wall II corresponding to the side wall I; From outside to inside, a pressing plate, a sealing ring, and a window are arranged in sequence to form the ray optical path together with the through hole III; The pressing plate is provided with a through hole IV, and coaxial blind holes III corresponding to the through hole IV are provided on the side wall I and the side wall II of the cell body. The through hole IV and the blind hole III are connected by a compression bolt; The material of the window is selected from at least one of plexiglass, ceramic, resin, and beryllium window; 7. The high-temperature in-situ Mössbauer spectroscopy reaction cell according to claim 1, characterized in that, A through hole V is provided at the center of the side wall III of the cell body as an air inlet; A through hole VI is provided at the center of the side wall IV of the cell body as an air outlet; Connectors I are provided on both the through hole V and the through hole VI; The diameter size of the connector I is selected from at least one of 3 mm, 6 mm, 8 mm, and 10 mm; 8. The high-temperature in-situ Mössbauer spectroscopy reaction cell according to claim 1, characterized in that, The The side wall III of the cell body is further provided with a through hole VII, and a connector II is provided at the through hole VII as a channel for circulating cooling water; The connector II is connected to a liquid guide pipe; The diameter size of the connecting piece II is selected from at least one of 3 mm, 6 mm, 8 mm, and 10 mm; The diameter of the liquid guide tube is 0.1 - 50 mm; The material of the liquid guide tube is selected from at least one of polyvinyl chloride, polytetrafluoroethylene, silica gel, and rubber.

9. The application of the high-temperature in-situ Mössbauer spectroscopy reaction cell according to any one of claims 1 to 8 in a thermal catalytic reaction, characterized in that, The thermal catalytic reaction is selected from at least one of carbon monoxide hydrogenation, carbon dioxide hydrogenation, and carbon monoxide oxidation.

10. The application according to claim 9, characterized in that, In the thermal catalytic reaction, the gas introduced into the air inlet is selected from at least one of hydrogen, carbon monoxide, carbon dioxide, and nitrogen.

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