An experimental catalyst synthesis and reaction apparatus

Abstract

This invention relates to an experimental catalyst synthesis and reaction apparatus, comprising a main reaction unit, a gas supply unit, a vacuum treatment unit, and a detection unit. The main reaction unit includes an inner quartz tube and an outer quartz tube. The inner quartz tube contains a quartz sand plate, quartz wool, a catalyst support bed, and a metal precursor placement stage, enabling preparation steps such as catalyst support pretreatment and metal precursor deposition. The gas supply unit uses multiple gas inlet branches combined with valves to switch between air, reducing gas, reactant gas, and inert gas to meet different needs such as calcination, reduction, reaction, and precursor introduction. The vacuum treatment unit performs high-precision pressure control. The detection unit uses a gas chromatograph to analyze the reaction products online, completing in-situ evaluation of catalyst activity. This achieves in-situ integration of catalyst preparation and activity evaluation, avoiding potential contamination or deactivation of the catalyst during transfer, and significantly improving the reliability of experimental data.

Description

Technical Field

[0001] This invention relates to the field of catalyst preparation technology, and in particular to an experimental catalyst synthesis and reaction apparatus. Background Technology

[0002] Supported catalysts are widely used in chemical, environmental protection, and energy fields due to their high activity, high selectivity, and good stability. Chemical vapor deposition is one of the commonly used methods for preparing supported catalysts. Its core is to uniformly load the active component onto the surface of the support through the vaporization and decomposition of the precursor.

[0003] Currently, laboratory apparatuses used for the preparation of supported catalysts via chemical vapor deposition (CVD) often suffer from problems such as fragmented structures and cumbersome operation. Catalyst preparation requires the coordination of multiple independent devices to complete steps such as precursor placement, support fixation, vacuum treatment, heating reaction, and cooling adsorption. The complex connections between these devices easily lead to problems such as gas leakage and difficulty in controlling vacuum levels, affecting the quality of catalyst preparation. Furthermore, their poor versatility makes it difficult to flexibly adjust parameters such as inlet gas type, reaction temperature, and reaction time according to different experimental needs, limiting their application in various catalyst preparation and evaluation experiments.

[0004] Meanwhile, the prepared catalyst needs to be transferred to a separate reaction evaluation device for activity testing. During the transfer process, the catalyst may be affected by contamination, loss of active components, etc., leading to a decrease in the accuracy of the evaluation results. This problem is particularly prominent for air-sensitive catalyst systems.

[0005] Therefore, an experimental catalyst synthesis and reaction apparatus is proposed to integrate catalyst preparation and activity evaluation, thereby solving the aforementioned problems in the prior art. Summary of the Invention

[0006] This invention provides an experimental catalyst synthesis and reaction apparatus to solve the problems mentioned in the above-mentioned technical background, such as the dispersed structure and cumbersome operation of existing catalyst synthesis and reaction apparatuses, and the need to transfer the prepared catalyst to another independent reaction evaluation apparatus for activity testing, which is easily affected by contamination, loss of active components, etc., leading to reduced accuracy of evaluation results.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: an experimental catalyst synthesis and reaction apparatus, comprising: The main reaction unit includes an outer quartz tube and an inner quartz tube. The inner quartz tube is movably disposed inside the outer quartz tube, and an annular chamber is formed between the outer quartz tube and the inner quartz tube. Quartz sand plate, quartz wool, catalyst support bed and metal precursor placement platform are arranged sequentially along its axial direction inside the inner quartz tube. A first branch port, a second branch port and a third branch port are provided on the upper tube wall of the inner quartz tube. The metal precursor placement platform is located below the first branch port. The gas supply unit includes a first gas source and a second gas source. The first gas source is connected to a third branch port through a first pipeline and a four-way valve, and is used to supply roasting, reduction and reaction gases to the inside of the inner quartz tube. The second gas source is connected to the first branch port through a second pipeline and a first two-way valve. An air jet is provided on the second pipeline. The outlet end of the air jet is connected to the first two-way valve, and the nozzle of the air jet faces the metal precursor placement platform. The vacuum processing unit includes a vacuum pump and a pressure gauge. A fourth branch port is provided on one side of the outer quartz tube. The vacuum pump is connected to the fourth branch port through a third pipeline and a second two-way valve. The pressure gauge is fixedly installed on the third pipeline. The detection unit includes a gas chromatograph. A fifth branch port is provided on one side of the outer quartz tube. The gas chromatograph is connected to the fifth branch port through a fourth pipeline and a three-way valve. An inlet pipe is provided between the gas chromatograph and the three-way valve. An exhaust pipe is connected to the other outlet of the three-way valve for venting the gas.

[0008] Preferably, the outer quartz tube is provided with a sealing plug for fixing the inner quartz tube, and the first branch port, the second branch port, the third branch port, the fourth branch port and the fifth branch port are all provided with threaded plugs for sealing.

[0009] Preferably, the first branch port is used to add a metal precursor, and the second branch port is used to add quartz wool and a catalyst support bed into the inner quartz tube.

[0010] Preferably, the quartz sand plate is fixedly disposed on the inner wall of the inner quartz tube to support the quartz wool and catalyst carrier bed.

[0011] Preferably, the first gas source includes an air pipeline, a reducing gas pipeline, and a reactant gas pipeline, wherein the air pipeline, the reducing gas pipeline, and the reactant gas pipeline are respectively connected to different inlets of the four-way valve.

[0012] Preferably, the second gas source is an inert gas pipeline, which is connected to the inlet end of the jet component.

[0013] Preferably, the inner quartz tube has a metal precursor inlet on its side wall that is connected to the first branch pipe opening. The metal precursor inlet is inclined to facilitate the smooth entry of the metal precursor powder into the inner quartz tube under the propulsion of the carrier gas.

[0014] Preferably, the metal precursor inlet is lower than the gas inlets of the first gas source and the second gas source.

[0015] Preferably, the jetting device is a pulse jetting device that uniformly sprays the metal precursor powder on the metal precursor placement stage into the inner quartz tube.

[0016] Preferably, the vacuum pump can reduce the pressure within the system to 10. -3 Below Pa, high-precision pressure control can be achieved by using the pressure gauge.

[0017] The beneficial effects of the experimental catalyst synthesis and reaction apparatus of the present invention are as follows: This invention utilizes inner and outer quartz tubes within the main reaction unit to achieve catalyst support pretreatment and metal precursor deposition. After vacuum dehydration and degassing, the surface active sites of the catalyst support are fully exposed, eliminating the need for transfer. The precursor powder blown in by the jet nozzle directly undergoes subsequent metal deposition at high temperatures, effectively improving the dispersion of the catalyst's active components. The prepared catalyst can be evaluated by the detection unit without transfer, achieving in-situ integration of catalyst preparation and activity evaluation. This avoids potential contamination or deactivation of the catalyst during transfer, significantly improving the reliability of experimental data. Furthermore, each unit is connected to a threaded sealing plug via pipelines, ensuring excellent system sealing and greatly enhancing the system's operational flexibility and experimental efficiency. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the main structure of the present invention; Figure 2 This is a schematic diagram of the quartz tube inside the main reaction unit of the present invention.

[0019] In the diagram: 1. First threaded plug; 2. Second threaded plug; 3. Third threaded plug; 4. Sealing plug; 5. Fourth threaded plug; 6. Fifth threaded plug; 7. First pipeline; 8. Second pipeline; 9. Third pipeline; 10. Fourth pipeline; 11. Inner quartz tube; 12. Outer quartz tube; 13. Metal precursor placement platform; 14. Catalyst carrier bed; 15. Quartz wool; 16. Quartz sand plate; 17. First branch port; 18. Second branch port; 19. Four-way valve; 20. First two-way valve; 21. First two-way valve; 22. Three-way valve; 23. Air pipeline; 24. Reducing gas pipeline; 25. Reaction gas pipeline; 26. Inert gas pipeline; 27. Jet jet; 28. Inlet pipe; 29. ​​Exhaust pipe; 30. Gas chromatograph; 31. Pressure gauge; 32. Vacuum pump. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The protection scope of the present invention is not limited to the specific implementation. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0021] like Figures 1-2 As shown, an experimental catalyst synthesis and reaction apparatus includes: The main reaction unit includes an outer quartz tube 12 and an inner quartz tube 11. The inner quartz tube 11 is movably disposed inside the outer quartz tube 12, forming an annular chamber between the outer quartz tube 12 and the inner quartz tube 11. The outer quartz tube 12 is provided with a sealing plug 4 for fixing the inner quartz tube 11. A quartz sand plate 16, quartz wool 15, a catalyst carrier bed 14, and a metal precursor placement platform 13 are sequentially arranged along the axial direction inside the inner quartz tube 11. Plate 16, quartz wool 15, catalyst carrier bed 14 and metal precursor placement platform 13 are arranged from bottom to top. The upper tube wall of the inner quartz tube 11 is provided with a first branch port 17, a second branch port 18 and a third branch port. The metal precursor placement platform 13 is located below the first branch port 17. The first branch port 17, the second branch port 18 and the third branch port are respectively provided with a first threaded plug 1, a second threaded plug 2 and a third threaded plug 3 for sealing. The gas supply unit includes a first gas source and a second gas source. The first gas source is connected to a third branch port through a first pipeline 7 and a four-way valve 19, and is used to supply calcination, reduction and reaction gases to the interior of the inner quartz tube 11. The second gas source is connected to a first branch port 17 through a second pipeline 8 and a first two-way valve 20. An air jet 27 is provided on the second pipeline 8. The outlet end of the air jet 27 is connected to the first two-way valve 20, and the nozzle of the air jet 27 faces the metal precursor placement platform 13, and is used to uniformly spray the metal precursor powder on the metal precursor placement platform 13 into the inner quartz tube 11. The vacuum processing unit includes a vacuum pump 32 and a pressure gauge 31. A fourth branch port is provided on one side of the outer quartz tube 12. The fourth branch port is sealed with a fourth threaded plug 5. The vacuum pump 32 is connected to the fourth branch port through a third pipeline 9 and a second two-way valve 21. It is used to evacuate the reaction system or provide a negative pressure environment. The pressure gauge 31 is fixed on the third pipeline 9 and is used to monitor the internal pressure changes of the system in real time. The detection unit includes a gas chromatograph 30. A fifth branch port is provided on one side of the outer quartz tube 12, and a fifth threaded plug 6 is provided on the fifth branch port for sealing. The gas chromatograph 30 is connected to the fifth branch port through a fourth pipeline 10 and a three-way valve 22 for online analysis of the composition and content of reaction products, and to realize in-situ evaluation of catalyst performance. An inlet pipe 28 is provided between the gas chromatograph 30 and the three-way valve 22. The other outlet of the three-way valve 22 is connected to an exhaust pipe 29 for venting the gas or connecting it to an absorption device.

[0022] The main reaction unit can be flexibly switched and connected with the gas pretreatment unit, detection unit and vacuum treatment unit through the four-way valve 19, the three-way valve 22, the first two-way valve 20 and the second two-way valve 21.

[0023] The first branch port 17 is used to add a metal precursor, and the second branch port 18 is used to add quartz wool 15 and catalyst support bed 14 into the inner quartz tube 11.

[0024] The quartz sand plate 16 is fixedly installed on the inner wall of the inner quartz tube 11 to support the quartz wool 15 and the catalyst carrier bed 14, preventing them from shifting under the impact of airflow.

[0025] The first gas source includes an air pipeline 23, a reducing gas pipeline 24, and a reaction gas pipeline 25. The air pipeline 23, the reducing gas pipeline 24, and the reaction gas pipeline 25 are respectively connected to different inlets of the four-way valve 19. The gas introduced into the air pipeline 23 is dry air, which is used for the calcination treatment of the catalyst. The gas introduced into the reducing gas pipeline 24 is hydrogen or other reducing gas, which is used for the reduction treatment of the catalyst. The gas introduced into the reaction gas pipeline 25 is a reaction gas, which is used for the evaluation of the catalyst activity, so as to facilitate the precise introduction of the required gas into the reaction system.

[0026] The second gas source is an inert gas pipeline 26, which is connected to the inlet end of the jet 27. The inert gas pipeline 26 is connected to argon or other inert gases that do not affect the catalyst.

[0027] The inner quartz tube 11 has a metal precursor inlet on its side wall that is connected to the first branch port 17. The metal precursor inlet is inclined so that the metal precursor powder can smoothly enter the inner quartz tube 11 under the propulsion of the carrier gas.

[0028] The metal precursor inlet is lower than the gas inlets of the first and second gas sources to prevent the metal precursor powder from entering the gas pipeline with the airflow.

[0029] The jetting component 27 is a pulse jetting component. The airflow generated by the pulse evenly sprays the metal precursor powder on the metal precursor placement platform 13 into the inner quartz tube 11.

[0030] The vacuum pump 32 can reduce the pressure inside the system to 10. -3 Below Pa, high-precision pressure regulation can be achieved by using the pressure gauge 31.

[0031] When using the catalyst, the following steps are performed: First, close the threaded plugs on the first branch port 17, the second branch port 18, the third branch port, the fourth branch port, and the fifth branch port. Then, open the second threaded plug 2 on the second branch port 18. Place the quartz wool 15 and the catalyst carrier into the inner quartz tube 11 one after the other and then close the plug. Connect and seal the inner quartz tube 11 and the outer quartz tube 12 through the threaded sealing plug 4. Adjust the height of the inner quartz tube 11. Open the first threaded plug 1 and place the metal precursor powder on the metal precursor placement platform 13 below the first branch port 17 and then close the plug. Place the lower end of the outer quartz tube 12 into a vertical tube furnace. Connect the third pipe 9 on the fourth branch port of the outer quartz tube 12 to the second two-way valve 21. Connect the first branch port of the inner quartz tube 11 to the first two-way valve 20 through the second pipe 8. Close the first two-way valve 20. Open the fourth threaded plug 5, the second two-way valve 21, and the vacuum pump 32 to evacuate to a vacuum level of 10. -3Pa, the catalyst support is pretreated by heating to the set temperature through a tube furnace to remove adsorbed moisture and impurity gases from the surface. After the system pressure stabilizes, the fourth threaded plug 5 and the second two-way valve 21 are closed, the vacuum pump 32 is turned off, and the vacuuming is stopped. The tube furnace is adjusted to the sublimation temperature of the metal precursor. The first two-way valve 20 is opened, and argon or other inert gas that does not affect the catalyst is introduced through the jet injector 27. This allows the metal precursor powder to enter the inner quartz tube 11 along with the carrier gas. The first two-way valve 20 and the jet injector 27 are then closed. The metal precursor powder undergoes decomposition and vaporization in the high-temperature environment inside the inner quartz tube 11 and comes into contact with the catalyst support. After reacting for a period of time, the outer quartz tube 12 is removed from the vertical tube furnace and quickly placed in liquid nitrogen for cooling, so that the generated metal atoms are uniformly dispersed on the catalyst support. On the surface, the outer quartz tube is removed from liquid nitrogen and heated to room temperature. Then, the fourth threaded plug 5, the second two-way valve 21, and the vacuum pump 32 are opened to remove excess residual gas by evacuation and then closed. The outer quartz tube 12 is then placed in a vertical tube furnace. The third threaded plug 3 and the fifth threaded plug 6 are opened, and air is connected through the four-way valve 19 and the air outlet 29 is connected through the three-way valve 22. The introduced air calcines the catalyst at a certain temperature. After calcination, the third threaded plug 3, the fifth threaded plug 6, and the four-way valve 19 are closed to form a highly dispersed supported metal catalyst.

[0032] Next, the catalyst activity is evaluated: the fourth threaded plug 5, the second two-way valve 21, and the vacuum pump 32 are opened to remove excess residual air by evacuation and then closed. The third threaded plug 3 and the fifth threaded plug 6 are opened, and hydrogen or other reducing gases are connected through the four-way valve 19. The outlet 29 is connected through the three-way valve 22. The temperature of the tubular furnace is adjusted, and the prepared supported metal catalyst is reduced at a certain temperature. After calcination, the third threaded plug 3, the fifth threaded plug 6, and the four-way valve 19 are closed, and the hydrogen supply is stopped. The fourth threaded plug 5, the second two-way valve 21, and the vacuum pump 32 are opened, and excess residual hydrogen is removed by evacuation and then closed. The third threaded plug 3 and the fifth threaded plug 6 are opened, and the reaction gas is connected through the four-way valve 19. An appropriate reaction temperature is selected according to the target reaction, and the inlet 28 of the gas chromatograph 30 is connected through the three-way valve 22 to perform online analysis of the reaction products, monitor the formation rate and selectivity of the target products in real time, and evaluate the performance of the catalyst.

[0033] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An experimental catalyst synthesis and reaction apparatus, characterized in that: include: The main reaction unit includes an outer quartz tube and an inner quartz tube. The inner quartz tube is movably disposed inside the outer quartz tube, and an annular chamber is formed between the outer quartz tube and the inner quartz tube. Quartz sand plate, quartz wool, catalyst support bed and metal precursor placement platform are arranged sequentially along its axial direction inside the inner quartz tube. A first branch port, a second branch port and a third branch port are provided on the upper tube wall of the inner quartz tube. The metal precursor placement platform is located below the first branch port. The gas supply unit includes a first gas source and a second gas source. The first gas source is connected to a third branch port through a first pipeline and a four-way valve, and is used to supply roasting, reduction and reaction gases to the inside of the inner quartz tube. The second gas source is connected to the first branch port through a second pipeline and a first two-way valve. An air jet is provided on the second pipeline. The outlet end of the air jet is connected to the first two-way valve, and the nozzle of the air jet faces the metal precursor placement platform. The vacuum processing unit includes a vacuum pump and a pressure gauge. A fourth branch port is provided on one side of the outer quartz tube. The vacuum pump is connected to the fourth branch port through a third pipeline and a second two-way valve. The pressure gauge is fixedly installed on the third pipeline. The detection unit includes a gas chromatograph. A fifth branch port is provided on one side of the outer quartz tube. The gas chromatograph is connected to the fifth branch port through a fourth pipeline and a three-way valve. An inlet pipe is provided between the gas chromatograph and the three-way valve. An exhaust pipe is connected to the other outlet of the three-way valve for venting the gas.

2. The experimental catalyst synthesis and reaction apparatus according to claim 1, characterized in that: The outer quartz tube is provided with a sealing plug for fixing the inner quartz tube, and the first branch port, the second branch port, the third branch port, the fourth branch port and the fifth branch port are all provided with threaded plugs for sealing.

3. The experimental catalyst synthesis and reaction apparatus according to claim 2, characterized in that: The first branch port is used to add metal precursors, and the second branch port is used to add quartz wool and catalyst support bed into the inner quartz tube.

4. The experimental catalyst synthesis and reaction apparatus according to claim 1, characterized in that: The quartz sand plate is fixedly installed on the inner wall of the inner quartz tube to support the quartz wool and catalyst carrier bed.

5. The experimental catalyst synthesis and reaction apparatus according to claim 1, characterized in that: The first gas source includes an air pipeline, a reducing gas pipeline, and a reactant gas pipeline, which are respectively connected to different inlets of the four-way valve.

6. The experimental catalyst synthesis and reaction apparatus according to claim 1, characterized in that: The second gas source is an inert gas pipeline, which is connected to the inlet end of the jet component.

7. The experimental catalyst synthesis and reaction apparatus according to claim 1, characterized in that: The inner quartz tube has a metal precursor inlet on its side wall that is connected to the first branch pipe opening. The metal precursor inlet is inclined to facilitate the smooth entry of the metal precursor powder into the inner quartz tube under the propulsion of the carrier gas.

8. The experimental catalyst synthesis and reaction apparatus according to claim 7, characterized in that: The metal precursor inlet is lower than the gas inlets of the first and second gas sources.

9. The experimental catalyst synthesis and reaction apparatus according to claim 1, characterized in that: The jetting device is a pulse jetting device that uniformly sprays the metal precursor powder on the metal precursor placement stage into the inner quartz tube.

10. An experimental catalyst synthesis and reaction apparatus according to claim 1, characterized in that: The vacuum pump can reduce the pressure within the system to 10. -3 Below Pa, high-precision pressure control can be achieved by using the pressure gauge.

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