Uniform heat photocatalytic reactor suitable for gas-solid phase reaction

Abstract

The invention discloses a uniform-heat photocatalytic reactor suitable for gas-solid phase reaction, and aims to solve the problems of non-uniform heating of a sample, insufficient contact between a catalyst and reaction gas and generation of a thermocatalytic effect in a metal reaction cavity in the existing reactor. According to the reactor, the nonmetal reaction cavity is adopted, so that thermocatalytic background noise generated by metal materials is avoided, and meanwhile, it is ensured that a sample is uniformly heated in the photocatalytic reaction process. The quartz reaction chamber provided by the invention can ensure full contact between the catalyst and the reaction gas, and improves the catalytic efficiency. The reactor is simple in structure, convenient to operate and suitable for various gas-solid phase photocatalytic reaction experiments. The catalyst is suitable for gas-solid phase catalytic reactions such as ammonia decomposition hydrogen production and carbon dioxide reduction, and is widely applied to the fields of environmental protection and energy conversion.

Description

Technical Field

[0001] The present invention belongs to the technical field of photocatalysis, and in particular relates to a uniform heating photocatalytic reactor suitable for gas-solid phase reactions, and is suitable for gas-solid phase catalytic reactions such as ammonia decomposition to produce hydrogen and carbon dioxide reduction. Background Art

[0002] In the field of catalytic reaction research, photocatalysis and thermal catalysis are two important research directions. Especially when exploring the mechanism of photothermal coupled catalytic reaction, it is particularly important to accurately distinguish the contribution of light and heat to the catalytic process. However, in actual experimental devices, the accuracy of experimental results is often adversely affected due to problems with equipment design and material selection.

[0003] The existing Harrick reactor is widely used in the study of photothermal catalytic reactions. The reactor usually uses metal materials as the reaction chamber and adopts external heating for temperature control. However, although metal materials have good thermal conductivity, they may participate in thermal catalytic reactions under high temperature conditions, resulting in additional thermal catalytic signal interference in the experiment. This interference makes it difficult to distinguish the effects of photocatalysis and thermal catalysis independently, and the credibility of the experimental results is reduced. Especially when studying the photothermal effect, it becomes more difficult to accurately determine the respective contributions of light and heat. In addition, the traditional Harrick reactor is prone to uneven heating during the heating process of the catalyst sample. Due to the temperature difference in different areas of the catalyst, the activity of the reaction may be affected by the uneven thermal field, and stable and repeatable experimental data cannot be obtained.

[0004] Specifically, the external heating method of the Harrick reactor easily leads to inconsistent surface and internal temperatures of the sample. Especially in the case of uneven heating, different areas of the catalyst sample will experience different temperature gradients. This not only affects the overall reaction activity of the catalyst, but may also cause some areas to be overheated or underheated, thus misleading the experimental results. In addition, the thermal catalytic effect of the metal chamber will further mask the photocatalytic effect, making it difficult for researchers to accurately evaluate the specific role of light and temperature in the catalytic reaction.

[0005] In summary, the existing Harrick reactor has technical bottlenecks such as uneven heating of the catalyst and interference of thermal catalytic signals caused by the metal chamber when conducting photothermal catalytic experiments, which limits its application in photothermal coupled catalytic research. In this context, developing a reactor that can provide a more uniform heating environment and avoid interference from metal materials has become a key direction to solve this technical problem. Summary of the invention

[0006] The present invention provides a reactor for photothermal coupled catalytic reactions, aiming to solve the problems of uneven heating of catalysts and interference of thermal catalytic signals in existing devices. The present invention provides a uniform heating photocatalytic reactor suitable for gas-solid phase reactions. By adopting a quartz reaction chamber, precise temperature monitoring and uniform heating, combined with a light source and temperature detection equipment, it realizes the independent determination of the respective contributions of light and heat to the catalytic reaction. It can not only independently distinguish the effects of light and heat, but also ensure the temperature uniformity and stability of the catalyst during the experiment, thereby obtaining more accurate experimental results.

[0007] In order to achieve the purpose of the present invention, the present invention provides a uniform heating photocatalytic reactor suitable for gas-solid phase reaction, comprising a quartz reaction chamber, a tubular furnace uniform heating device, a light excitation system and a surface temperature observation system; The quartz reaction chamber comprises a large tube and a small tube, one end of the large tube is provided with an air inlet and a window for transmitting laser light so that the laser light can irradiate the catalyst surface, the other end of the large tube is connected to the small tube, and the large tube and the small tube are in communication, and a catalyst bed is provided inside the small tube and near the connection between the small tube and the large tube; The tubular furnace uniform heating device comprises a tubular furnace body, a heating element, a temperature sensor and a temperature control system. The tubular furnace body comprises a furnace cavity. The heating element is arranged in the furnace cavity to perform surrounding heating on the sample in the furnace cavity. Both the large tube and the small tube are located in the furnace cavity. The temperature sensor is used to monitor the temperature of the catalyst during the reaction process, and the temperature sensor is connected to the temperature control system. The light excitation system is used to provide a light source for the catalytic reaction, and the laser emission point of the light excitation system is opposite to the window; The surface temperature observation system is used to observe the surface temperature of the catalyst.

[0008] Furthermore, a gas flow system is provided, and the gas flow system is communicated with the gas inlet and is used to introduce reaction gas into the quartz reaction chamber.

[0009] Furthermore, the diameter of the furnace chamber of the tubular furnace body matches the quartz reaction chamber.

[0010] Furthermore, the catalyst in the catalyst bed is in the form of powder, granules or coating.

[0011] Furthermore, the material of the window piece is any one of quartz, glass, CaF2, sapphire, BaF2, NaCl, KBr, ZnS, CdTe, MgF2, CdS and ZnSe.

[0012] Furthermore, the heating element is any one of a resistance wire, a silicon-molybdenum rod and a silicon-carbon rod.

[0013] Furthermore, the temperature sensor is any one of a thermocouple, a thermal resistor (RTD), a thermistor, an optical fiber temperature sensor, and a semiconductor temperature sensor.

[0014] Further, the temperature sensors are distributed around the catalyst bed, or the temperature sensors are inserted into the catalyst bed.

[0015] Furthermore, a gas analyzer is also provided, and the gas analyzer is connected to the gas outlet of the small tube through a pipeline.

[0016] Furthermore, the surface temperature observation system includes an infrared thermal imager located outside the quartz reaction chamber, or includes a temperature sensor for directly contacting the catalyst surface.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: (1) The present invention uses quartz as the reactor chamber. Quartz has excellent chemical inertness and high transparency, which can avoid the interference of thermal catalytic signals caused by traditional metal chambers and ensure the purity of photocatalytic and thermal catalytic reaction conditions. At the same time, the reaction chamber made of quartz can withstand high temperatures and has excellent light transmittance, which is particularly suitable for laser irradiation requirements in photocatalytic reactions.

[0018] (2) In order to accurately monitor the temperature of the catalyst, the present invention sets a temperature sensor to measure the temperature change of the catalyst sample in real time to ensure the accuracy of the temperature. Compared with traditional external temperature measurement, this design can better reflect the actual heating state of the catalyst, thereby providing more accurate thermodynamic data for the experiment.

[0019] (3) In terms of heating method, the present invention adopts a surrounding heating structure of a tubular furnace. Through this heating method, the sample can be heated evenly from all directions, avoiding the local heating problem in the traditional Harrick reactor and ensuring that the catalyst is heated more fully and evenly. This improvement significantly improves the reliability of the experiment, making the catalytic reaction more stable and the reaction conditions closer to the actual application environment.

[0020] (4) During the photocatalytic reaction, the present invention provides a window for transmitting laser light and irradiating the catalyst surface to stimulate the photocatalytic reaction. The window preferably uses a calcium fluoride (CaF2) window. The calcium fluoride window has excellent light transmittance and can ensure that the laser energy is effectively transferred to the catalyst surface to achieve an accurate photocatalytic excitation process. At the same time, in order to distinguish the respective contributions of photocatalysis and thermal catalysis to the reaction, the present invention introduces an infrared thermal imager during the experiment to monitor the temperature distribution on the catalyst surface in real time. The surface temperature observation system can accurately capture the temperature changes on the catalyst surface, helping researchers to clearly understand the independent effects of light and heat in the reaction. The reactor has a compact structure, is easy to disassemble and clean, and is suitable for gas-solid phase photocatalytic reactions under different experimental environments.

[0021] (5) Through this reactor, researchers can accurately distinguish the contributions of photocatalysis and thermocatalysis in experiments, avoid the problem of thermocatalytic signal interference caused by the metal cavity, and ensure uniform heating of the catalyst. In addition, the surface temperature observation system can use an infrared thermal imager, a combination of laser irradiation and infrared temperature monitoring, so that the thermodynamic changes in the photothermal coupling reaction can be more accurately evaluated. The present invention provides a reliable and accurate experimental method for the study of photothermal catalytic reactions, which has important application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic structural diagram of a uniform heating photocatalytic reactor suitable for gas-solid phase reactions provided in an embodiment of the present invention.

[0023] Figure 2 for Figure 1 Side view of the gas-solid phase photocatalytic reactor shown.

[0024] Figure 3 It is a simplified diagram of the large tube and the small tube in the embodiment of the present invention.

[0025] Among them, 1-tubular furnace body, 2-temperature sensor, 3-gas outlet, 4-gas inlet pipe, 5-infrared thermal imager, 6-laser generator, 7-catalyst, 8-quartz wool, 9-first sealing ring, 10-second sealing ring, 11-heating element, 12-laser illumination, 13-window, 14-large tube, 15-small tube. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] See also Figure 1 The present invention provides a novel uniform heating photocatalytic reactor suitable for gas-solid phase reaction, comprising a quartz reaction chamber, a tubular furnace uniform heating device, a light excitation system and a surface temperature observation system.

[0028] The structural design of the quartz reaction chamber: In order to ensure that the reaction gas can fully contact the catalyst, the reaction chamber is designed as a structure in which a large tube 14 is connected to a small tube 15. This structure has the following advantages: (1) Large tube 14: used to introduce reaction gas and provide pretreatment space for uniform flow of reaction gas. One end of the large tube 14 is provided with an air inlet and a window 13 for passing laser so that the laser can irradiate the catalyst surface. In some embodiments of the present invention, a flange adapter of metal and glass is connected to one end of the large tube 14, and a first sealing ring 9 is provided between the flange adapter and the large tube 14. The window 13 is fixed at the end of the flange adapter to form a flange sealing structure. One end of the air inlet pipe 4 (such as a steel pipe) is embedded in the flange adapter and communicates with the air inlet of the large tube 14. The design of the large tube 14 ensures the uniformity of gas pressure and flow rate, avoids the gas from flowing too fast or too slow before entering the reaction area, and ensures stability during the reaction process.

[0029] (2) Small tube 15: The small tube 15 is connected to the other end of the large tube 14, and the large tube 14 and the small tube 15 are in communication. A catalyst bed is provided inside the small tube 15 and near the connection between the small tube 15 and the large tube 14.

[0030] The catalyst is placed in the small tube 15, and the catalyst can be fixed in the form of powder, particles or coating near the connection between the small tube 15 and the large tube 14. This not only ensures that the contact area between the catalyst and the gas is maximized, but also optimizes the reaction conditions by adjusting the loading method and thickness of the catalyst.

[0031] During operation, the catalyst is placed in the small tube 15 near the large tube 14, and the reaction gas is introduced into the small tube 15 after passing through the large tube 14. In the area of ​​the small tube 15, it is only necessary to lay the catalyst 7 near the connection between the small tube 15 and the large tube 14 to ensure that all reaction gases must pass through the catalyst bed, ensuring sufficient contact between the reaction gas and the catalyst. This design can avoid the situation where the gas bypasses the catalyst, ensure the efficient use of the catalyst, and maximize the effect of the catalytic reaction.

[0032] In some embodiments of the present invention, one end of the small tube 15 is connected to the large tube 14, and the other end of the small tube 15 is provided with a stainless steel joint, and a second sealing ring 10 is provided between the joint and the small tube 15. The joint is connected to the gas analyzer GC through a pipeline (such as a stainless steel pipe) to introduce the gas at the outlet of the small tube 15 into the gas analyzer GC for gas composition analysis.

[0033] In some embodiments of the present invention, quartz wool 8 is arranged inside the small tube 15 and close to the catalyst bed.

[0034] The reaction chamber is made of quartz material, which is not only relatively cheap, easy to disassemble and clean, but also has good high temperature resistance, corrosion resistance and excellent light transmittance, making it particularly suitable for use in photocatalytic reactions. The design of the quartz reaction chamber is based on the needs of gas-solid phase catalytic reactions, and adopts a "large tube connected to small tube" structural layout to ensure the uniformity of gas flow and maximize the contact efficiency between the catalyst and the reaction gas.

[0035] The reaction chamber is made of quartz material and has the following advantages: (1) High temperature resistance: Quartz material can withstand high temperature changes and is suitable for high temperature reaction environments, ensuring that the reaction chamber will not be damaged by high temperature reactions.

[0036] (2) Corrosion resistance: Quartz material has excellent corrosion resistance and can resist chemical corrosion of the chamber by reaction gases and catalysts, ensuring the long-term stable operation of the reactor.

[0037] (3) Avoiding thermal catalytic effects: Unlike metal reaction chambers, quartz is a non-metallic material and will not induce additional thermal catalytic effects at high temperatures. This avoids the background noise interference caused by metal materials, ensures that only the catalyst plays a catalytic role in the experiment, and improves the accuracy of the experimental data.

[0038] (4) Easy to disassemble and clean: The quartz reaction chamber of the present invention can be designed in a modular manner, which is convenient for disassembly and assembly, and is easy to clean and maintain after the experiment. The surface of the quartz material is smooth and corrosion-resistant, and it is not easy for reactants to remain during the cleaning process, ensuring that when the experimental conditions or reactants are changed, the reaction chamber can be quickly cleaned and reassembled to ensure the purity of the next experiment and the consistency of the data. The disassembly and assembly structure is simple and easy to operate, and the experimenter can quickly perform maintenance, shortening the preparation time and increasing the efficiency of the experiment.

[0039] (5) Low material cost: Quartz material is relatively economical compared to other high temperature and corrosion resistant materials. This effectively controls the production cost of the reactor and makes it suitable for large-scale manufacturing and application. At the same time, the long life of quartz material further reduces the maintenance and replacement costs of the reactor, making it extremely cost-effective.

[0040] In some embodiments of the present invention, the window 13 is a CaF2 window. In the case of taking both visible light and infrared transmission into consideration, CaF2 is a better choice. In other embodiments, if higher requirements are required in terms of cost and hardness, any material such as quartz, glass, sapphire, BaF2, NaCl, KBr, ZnS, CdTe, MgF2, CdS and ZnSe can be selected to make the window.

[0041] Among them, the CaF2 window has very good optical transmittance, and has excellent transmittance in the wide spectral range of 150 nm to 10 µm, which is suitable for optical applications of ultraviolet, visible and near-infrared light. It can not only transmit lasers to the greatest extent, but also take into account the working wavelength of infrared thermal imagers, which is conducive to infrared thermal imagers observing the temperature of the catalyst 7 surface.

[0042] The gas-solid phase photocatalytic reactor of the present invention adopts a tubular furnace as the main uniform heating device to ensure the uniformity of heating of the catalyst and the precise control of the reaction temperature during the reaction. The tubular furnace is closely combined with the quartz reaction chamber structure to provide a stable and controllable heat source for the photocatalytic reaction. The tubular furnace uniform heating device includes a tubular furnace body 1, a heating element 11, a temperature sensor 2 and a temperature control system (the temperature control system adopts existing equipment, and its structure and working principle are not described in detail here), ensuring the stability of the reaction environment.

[0043] (1) Tubular furnace body 1: The material of the tubular furnace body 1 is a high temperature resistant and corrosion resistant material. In some embodiments of the present invention, alumina ceramics are specifically used, which are suitable for high temperature operating environments. The diameter of the furnace cavity of the tubular furnace body matches the quartz reaction cavity to ensure that the quartz reaction cavity can be completely placed in the heating area of ​​the furnace cavity of the tubular furnace body 1, so that the catalyst and reaction gas are heated evenly during the heating process. The furnace cavity of the tubular furnace body 1 is designed as a closed structure to prevent external temperature fluctuations from interfering with the reaction environment and ensure temperature stability during the heating process. The uniform heating device of the tubular furnace can perform precise temperature control in the range of room temperature to 1100°C, which is suitable for the temperature requirements of various gas-solid phase catalytic reactions.

[0044] (2) Distribution of heating elements: The tubular furnace body 1 includes a furnace cavity, and the heating elements 11 are evenly distributed around the interior of the furnace cavity to heat the sample in the furnace cavity. The heating element 11 is made of high-performance materials (in some embodiments of the present invention, the high-performance material is a silicon-molybdenum rod or a silicon-carbon rod), provides heat through the principle of resistance heating, can quickly respond to temperature changes, and ensure the temperature uniformity of the entire heating area. The large tube 14 and the small tube 15 are both located in the furnace cavity, and the temperature sensor 2 is located inside the quartz reaction chamber to monitor the temperature of the catalyst during the reaction, and the temperature sensor 2 is connected to the temperature control system.

[0045] In some embodiments of the present invention, the ends of the large tube 14 and the small tube 15 where the joints are provided are located outside the furnace cavity. The joints are made of stainless steel. Stainless steel has a thermal catalytic effect and interferes with the effect of the catalyst itself. Therefore, it is placed outside the furnace cavity to avoid interference.

[0046] In some embodiments of the present invention, the power of the heating element 11 can be adjusted according to the experimental requirements, so that the heating rate can be accurately controlled. This flexible adjustment capability enables the tube furnace uniform heating device to adapt to the requirements of different reaction conditions and provide a stable heating environment.

[0047] In some embodiments of the present invention, the heating element 11 is a resistance wire.

[0048] In order to achieve real-time monitoring of the reaction temperature, the present invention is provided with a temperature sensor 2 at a key position of the quartz reaction chamber. Specifically, in some embodiments of the present invention, the temperature sensor 2 is distributed around the catalyst, and in other embodiments, the temperature sensor 2 can also be directly inserted into the catalyst to monitor the temperature of the catalyst in real time during the reaction.

[0049] In some embodiments of the present invention, the temperature sensor 2 is a thermocouple. The thermocouple can be in direct contact with the catalyst, and the temperature of the catalyst is monitored in real time by the thermocouple during the heating process and fed back to the temperature control system to ensure accurate control of the reaction temperature and stable performance of the catalyst. In other embodiments, the temperature sensor 2 can also be a thermal resistor or an optical fiber temperature sensor or a semiconductor temperature sensor to provide more flexible temperature measurement options to adapt to different temperature measurement requirements and environmental conditions.

[0050] By inputting the signal collected by the temperature sensor 2 into the temperature control system equipped with the uniform heating device of the tubular furnace, the temperature change of the heating area can be accurately sensed to ensure the uniform temperature of the catalyst 7. The temperature data is fed back to the temperature control system in real time. If the temperature deviates, the temperature control system can immediately adjust the heating power to return the temperature to the set value, ensuring that the catalyst is always within the optimal reaction temperature range.

[0051] The light excitation system is used to provide a light source for the catalytic reaction. It can emit ultraviolet light, visible light or near-infrared light. The emitted light beam penetrates the window 13 and directly illuminates the catalyst area. The intensity and wavelength of the light source can be adjusted according to the experimental requirements to match different types of catalysts and reaction conditions. The light excitation system is an existing system, and its structure and working principle are not described in detail here. The laser beam in the shape of a flat-top square hat emitted by the light excitation system can ensure that the catalyst is evenly illuminated and improve the photocatalytic efficiency. Combined with the light transmission characteristics of the CaF2 reaction chamber, the light excitation system can significantly improve the light absorption efficiency of the catalyst and enhance the catalytic reaction effect.

[0052] In some embodiments of the present invention, the surface temperature observation system includes an infrared thermal imager located outside the quartz reaction chamber. The working principle of the infrared thermal imager is based on infrared radiation detection. All objects with a temperature higher than absolute zero (-273.15°C) will emit infrared radiation. The higher the temperature, the greater the intensity of the radiation. The infrared thermal imager can detect this infrared radiation without contact and convert it into a visible light image, thereby displaying the temperature distribution of the object.

[0053] In one embodiment of the present invention, a gas-solid phase photocatalytic reactor for decomposing ammonia (NH3) is shown. The reactor is specifically used for decomposing ammonia to produce hydrogen as a clean energy carrier. In this embodiment, the specific configuration is as follows: Reaction chamber and catalyst design: Ru-MXene catalyst is placed in the small tube 15 of the quartz reaction chamber. The catalyst has excellent photocatalytic activity and is particularly suitable for the decomposition of ammonia. The large tube 14 of the quartz reaction chamber is connected to the small tube 15 structure to ensure that ammonia passes through the catalyst bed and fully contacts with the Ru-MXene catalyst, and a temperature sensor 2 is inserted in the Ru-MXene catalyst, and the temperature sensor 2 is a thermocouple.

[0054] Heating and temperature control: The temperature of the uniform heating device of the tube furnace is set to 400°C to ensure that this temperature can activate the catalyst and is suitable for the thermal catalytic temperature of the decomposition of ammonia. The small tube 15 made of quartz material has no catalytic activity and can intrinsically react to the thermal catalytic effect of the Ru-MXene catalyst, which is conducive to comparing with the photocatalytic effect and deriving the contribution of hot electrons in the plasmon to the catalytic effect. The temperature sensor 2 can monitor the reaction temperature of the Ru-MXene catalyst in real time to ensure that the catalyst is heated evenly and will not be damaged by overheating.

[0055] Light excitation system: The light excitation system includes a laser generator 6. The laser generator 6 uses a near-infrared laser. The light emitted by the near-infrared laser enters the quartz reaction chamber through the CaF2 window to ensure that the surface of the Ru-MXene catalyst is evenly irradiated with laser light 12. The surface temperature of the catalyst is determined by an infrared thermal imager 5. The power of the light source is 600mW, and the light intensity can be adjusted according to the experimental conditions.

[0056] Gas flow: Ammonia enters the quartz reaction chamber through the air inlet of the large tube 14 through a flow meter, and is decomposed into nitrogen and hydrogen by the Ru-MXene catalyst. The composition changes of the gas at the outlet 3 of the small tube 15 can be monitored in real time by a gas analyzer to ensure that the ammonia is completely decomposed and the processing efficiency of the reactor meets expectations.

[0057] Through this embodiment, the reactor can efficiently photocatalyze the ammonia decomposition reaction and realize the ammonia cycle in hydrogen energy transportation, which has good industrial application prospects.

[0058] In another embodiment of the present invention, a gas-solid phase photocatalytic reactor suitable for carbon dioxide reduction reaction is described. In this embodiment, the quartz reaction chamber, the tubular furnace uniform heating device and the light excitation system are also key components, but the catalyst and reaction conditions are different. Among them: Quartz reaction chamber design: The reaction chamber is still made of quartz material, which can withstand a high temperature of 1200°C. The quartz reaction chamber also adopts a structure of a large tube 14 connected to a small tube 15. The small tube 15 is filled with a Cu / MgO-Al2O3 catalyst for photocatalytic CO2 reduction reaction.

[0059] Tube furnace uniform heating device: In this embodiment, the tube furnace is set at a temperature of 350°C to ensure catalyst activation and adapt to the reaction requirements of CO2 reduction. Temperature sensors 2 are distributed around the catalyst to ensure temperature uniformity and control accuracy.

[0060] Photoexcitation system: The photoexcitation system uses a wide wavelength range LED light source that can emit ultraviolet light, visible light or near-infrared light. The light enters the quartz reaction chamber through the CaF2 window. By adjusting the light intensity and wavelength, the best match between the light source and the Cu / MgO-Al2O3 catalyst is ensured to achieve efficient photocatalytic reaction. The surface temperature of the catalyst is determined by an infrared thermal imager 5 and compared with isothermal thermal catalysis. The light source intensity is set to 500 W / m², and the wavelength covers the range of 365-470nm to fully excite the catalyst surface reaction.

[0061] Gas flow and reduction process: CO2 gas passes through the gas flow system (the gas flow system is an existing system, and its structure and working principle are not described here) and enters the quartz reaction chamber through the air inlet of the large tube 14, and undergoes a photocatalytic reduction reaction with the Cu / MgO-Al2O3 catalyst in the small tube 15 to convert CO2 into methane (CH4) and carbon monoxide (CO). The composition and concentration of the reaction products can be monitored in real time by a gas analyzer to ensure that the reactor performance meets the design requirements.

[0062] This embodiment achieves efficient reduction of CO2, and the yields of product CH4 and CO are significantly improved, demonstrating the wide application potential of this reactor in the field of gas-solid phase photocatalysis.

[0063] The purpose of the aforementioned embodiment of the present invention is to provide a photocatalytic reactor that can effectively distinguish the independent contributions of photocatalysis and thermal catalysis, and solve the problems of uneven heating of the catalyst and thermal catalytic signal interference caused by metal materials in the traditional Harrick reactor. The embodiment of the present invention adopts a reaction chamber made of quartz material, accurately monitors the temperature of the catalyst through the temperature sensor 2, and performs surrounding heating of the tubular furnace to ensure that the catalyst is heated evenly and the temperature is controllable. At the same time, the laser is introduced through the window 13 to excite the photocatalytic reaction, and the surface temperature of the catalyst 7 is monitored in real time in combination with the surface temperature observation system, so that the independent effects of light and heat in the reaction can be accurately separated.

[0064] Obviously, the present invention is described in conjunction with preferred specific embodiments, but those skilled in the art should understand that various modifications and improvements can be made to the present invention without departing from the technical concept and protection scope of the present invention. Therefore, the protection scope of the present invention is not limited to the above specific embodiments, but should be based on the protection scope of the attached claims.

Claims

1. A uniform heating photocatalytic reactor suitable for gas-solid phase reaction, characterized in that: It includes a quartz reaction chamber, a tube furnace uniform heating device, a light excitation system and a surface temperature observation system; The quartz reaction chamber comprises a large tube and a small tube, one end of the large tube is provided with an air inlet and a window for transmitting laser light so that the laser light can irradiate the catalyst surface, the other end of the large tube is connected to the small tube, and the large tube and the small tube are in communication, and a catalyst bed is provided inside the small tube and near the connection between the small tube and the large tube; The tubular furnace uniform heating device comprises a tubular furnace body, a heating element, a temperature sensor and a temperature control system. The tubular furnace body comprises a furnace cavity. The heating element is arranged in the furnace cavity to perform surrounding heating on the sample in the furnace cavity. Both the large tube and the small tube are located in the furnace cavity. The temperature sensor is used to monitor the temperature of the catalyst during the reaction process, and the temperature sensor is connected to the temperature control system. The light excitation system is used to provide a light source for the catalytic reaction, and the laser emission point of the light excitation system is opposite to the window; The surface temperature observation system is used to observe the surface temperature of the catalyst.

2. A uniform heating photocatalytic reactor suitable for gas-solid phase reaction according to claim 1, characterized in that: A gas flow system is also provided, and the gas flow system is communicated with the gas inlet and is used for introducing reaction gas into the quartz reaction chamber.

3. The uniform heating photocatalytic reactor suitable for gas-solid phase reaction according to claim 1, characterized in that: The diameter of the furnace cavity of the tubular furnace body matches the quartz reaction chamber.

4. The uniform heating photocatalytic reactor suitable for gas-solid phase reaction according to claim 1, characterized in that: The catalyst in the catalyst bed is in the form of powder, granules or a coating.

5. The uniform heating photocatalytic reactor suitable for gas-solid phase reaction according to claim 1, characterized in that: The material of the window piece is any one of quartz, glass, CaF2, sapphire, BaF2, NaCl, KBr, ZnS, CdTe, MgF2, CdS and ZnSe.

6. The uniform heating photocatalytic reactor suitable for gas-solid phase reaction according to claim 1, characterized in that: The heating element is any one of a resistance wire, a silicon-molybdenum rod and a silicon-carbon rod.

7. The uniform heating photocatalytic reactor suitable for gas-solid phase reaction according to claim 1, characterized in that: The temperature sensor is any one of a thermocouple, a thermal resistor, a thermistor, an optical fiber temperature sensor, and a semiconductor temperature sensor.

8. The uniform heating photocatalytic reactor suitable for gas-solid phase reaction according to claim 1, characterized in that: The temperature sensors are distributed around the catalyst bed, or the temperature sensors are inserted into the catalyst bed.

9. The uniform heating photocatalytic reactor suitable for gas-solid phase reaction according to claim 1, characterized in that: A gas analyzer is also provided, and the gas analyzer is connected with the gas outlet of the small tube through a pipeline.

10. A uniform heating photocatalytic reactor suitable for gas-solid phase reaction according to any one of claims 1 to 9, characterized in that: The surface temperature observation system includes an infrared thermal imager located outside the quartz reaction chamber, or includes a temperature sensor for directly contacting the catalyst surface.

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