Spectrum coupling system based on TAP

Abstract

The invention provides a spectrum coupling system based on TAP, and relates to the field of transient dynamics and catalytic surface and interface catalysis research. The invention provides an expansion device based on the TAP on the first aspect, provides a Raman spectrum coupling system based on the TAP on the second aspect and provides a UV-Vis DRS spectrum coupling system based on the TAP on the third aspect. According to the invention, the TAP-based expansion device is coupled with the Raman spectrum device or the UV-Vis DRS spectrum device, so that the synchronous characterization of the structure and chemical properties of the active site / active component of the sample under in-situ and near working conditions can be realized.

Description

Technical Field

[0001] This invention relates to the field of transient dynamics and catalytic interface catalysis research, and in particular to a TAP-based spectral coupling system. Background Technology

[0002] In-situ (operando) spectroscopic techniques (Raman, UV-Vis, XRD, and XPS, etc.) characterize the dynamic evolution of catalyst structure, chemical state, and surface species under changing reaction conditions and time, thus studying the true active site structure, reaction mechanism, and structure-activity relationship of the catalyst under reaction conditions. In-situ Raman spectroscopy can be used to test and analyze the dynamic evolution of the crystal phase structure, coordination, polymerization state, relative oxygen vacancy concentration, and surface carbon area of ​​solid oxide catalysts during the reaction process. In-situ UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) can characterize the dynamic evolution of catalyst band structure, surface adsorption, and the coordination state and oxidation state of surface transition metal ions. However, current in-situ experiments are mostly conducted under steady-state conditions, and the steady-state kinetic information (e.g., selectivity and conversion) under specific reaction conditions (pressure and temperature) is difficult to use for analyzing, obtaining, and understanding the reaction mechanisms related to elementary reactions.

[0003] Temporal Analysis of Products (TAP) involves pulsed injection of minute amounts of reactant gas (e.g., as small as 0.01 nmol) into a microreactor containing a catalyst. High-time-resolution mass spectrometry is then used at the end of the microreactor to detect the transient response (time resolution up to 0.1 ms) of the gas exiting the catalyst bed. Based on the precise pulses and high-time-resolution data acquisition of TAP, a series of transient intrinsic kinetic data generated by TAP experiments can effectively reflect reaction intermediates, active sites, transient kinetics, and the microscopic mechanisms of chemical reactions related to elementary reactions. However, traditional TAP devices cannot directly obtain structural information related to active sites, surface adsorption, or surface residual species generated during the reaction. If spectroscopic characterization techniques can be coupled with TAP techniques, it is possible to simultaneously detect the intrinsic microscopic kinetics of the reaction and the transient response and changes of the active site structure during the reaction process under precise micro-scale gas pulse conditions. This allows for the study of the correlation between the catalyst active center structure, intermediate species, and intrinsic catalyst activity at the microscopic level, clarifying the key factors affecting catalytic performance, understanding the nature of catalytic reactions, and providing fundamental data for the design and creation of highly efficient catalysts.

[0004] Currently, there are no reports of combining commercial TAP reactors with spectroscopy, and there are no reports of such simultaneous characterization instruments both domestically and internationally. The challenges of coupling TAP devices with spectroscopic techniques lie in the space-constrained high-vacuum chamber, the small diameter of the reaction tube, the thin catalyst bed sandwiched between quartz sands, and the high-temperature environment. Therefore, there is an urgent need to develop a TAP-spectroscopy coupling system for interfacial catalysis research. Summary of the Invention

[0005] To address the aforementioned problems, the first aspect of this invention provides a TAP-based extension device that can couple a TAP-based extension device with a Raman spectroscopy device or a UV-Vis DRS spectroscopy device to achieve simultaneous characterization of the structure and chemical properties of active sites / active components of a sample under in-situ and near-operating conditions.

[0006] A TAP-based expansion device includes a vacuum chamber with a pulse mechanism at the top and a vacuum mechanism at the bottom. A microreactor is housed within the vacuum chamber. The microreactor includes a heat-insulating shielded cavity, within which an integrated reaction tube is located. The integrated reaction tube contains a reaction channel. The pulse outlet of the pulse mechanism is connected to the air inlet of the reaction channel. The reaction channel is suitable for placing a sample. A heating sleeve surrounds the outer wall of the integrated reaction tube. The vacuum chamber has a first light window in its side wall, the thermal insulation shielding cavity has a first light-transmitting hole in its side wall, the heating sleeve has a second light-transmitting hole in its side wall, and the integrated reaction tube has a second light window in its side wall. The TAP-based expansion device also includes a mass spectrometer. The mass spectrometer filament passes through the side wall of the vacuum chamber and enters the inner cavity of the thermal insulation shielding cavity. An expansion tube is also provided at the outlet of the reaction channel. The expansion tube extends towards the mass spectrometer filament but does not contact it. The outside of the vacuum chamber is suitable for placing a Raman spectrometer or a UV-Vis DRS device. The laser emitted by the Raman spectrometer or the xenon lamp emitted by the UV-Vis DRS device passes through the first light window, the first light-transmitting hole, the second light-transmitting hole, and the second light window in sequence and hits the sample surface. The Raman scattering signal reflected back from the sample is collected and analyzed by the Raman spectrometer, and the xenon lamp reflected back from the sample is collected and analyzed by the UV-Vis DRS device.

[0007] In one feasible embodiment provided by the present invention, the diameter of the first light-transmitting hole is 5-30 mm, the diameter of the second light-transmitting hole is 5-30 mm; the first light window is a planar light window with a diameter of 20-70 mm; the second light window is a planar light window with a thickness of 2-5 mm, a height of 5-20 mm, and a width of 2-10 mm; the signal collection angle α of the laser or xenon lamp reflected by the sample is 20-50°.

[0008] In one feasible embodiment provided by the present invention, the vacuum degree of the vacuum cavity is 10. -7 ~10 -10 mbar; and / or, the materials of the first and second light windows are both independently selected from fused silica glass or synthetic sapphire; and / or, the transmittance of the first and second light windows for 220–2000 nm light is ≥90%; and / or, the length of the integrated reaction tube is 30–100 mm; and / or, the diameter of the reaction channel is 3–6 mm; and / or, the distance between the expansion tube and the mass spectrometer filament is 2–10 mm; and / or, the heating sleeve is made of stainless steel; and / or, the vacuum mechanism further includes a vacuum gauge disposed in the side wall of the vacuum chamber; and / or, the top of the integrated reaction tube is also provided with a filter screen.

[0009] In one feasible embodiment provided by the present invention, the outer wall of the heating sleeve is provided with a plurality of heating wire grooves arranged sequentially along the axial direction of the heating sleeve, and each heating wire groove is provided with a heating wire; the outer wall of the heating sleeve is also provided with a thermocouple groove extending along the axial direction of the heating sleeve, the thermocouple groove extending to a position close to the sample, and a thermocouple is provided in the thermocouple groove; preferably, the heating range of the heating wire is room temperature to 1000℃.

[0010] In one feasible embodiment provided by the present invention, the pulse mechanism includes a pulse flange connected to the top of the vacuum chamber; a pulse valve is provided in the pulse flange, and the outlet of the pulse valve is connected to the air inlet of the reaction channel; a thermocouple connector and a heating wire connector are also provided in the pulse flange, the thermocouple connector is connected to the thermocouple, and the heating wire connector is connected to the heating wire; a water cooling channel is also provided in the pulse flange; and a sealing ring is provided between the pulse flange and the integrated reaction tube.

[0011] In one feasible embodiment provided by the present invention, the vacuum system includes a first molecular pump, a second molecular pump and a mechanical pump connected in sequence; the first molecular pump is connected to the inner cavity of the vacuum chamber.

[0012] In one feasible embodiment provided by the present invention, a host computer is also included, which is used to coordinate and control the pulse mechanism, mass spectrometer, Raman spectroscopy device, and UV-Vis DRS device.

[0013] The present invention also provides a method for using a TAP-based extension device, comprising the following steps:

[0014] Step 1): Evacuate the vacuum chamber using the vacuum mechanism in the TAP-based extension device to maintain the vacuum level at 10. -7 ~10 -10 mbar.

[0015] Step 2): The microreactor in the TAP-based extension device is heated to the reaction temperature, and the sample also reaches the reaction temperature at the same time;

[0016] Step 3): Different micro-pulses of reactive gas are injected into the reaction channel through the pulse mechanism in the TAP-based extension device, and react with the sample in the reaction channel;

[0017] Step 4): After the reactant gas reacts with the sample in Step 3, the unreacted reactant, reference gas, and product gas molecules enter the vacuum chamber through the expansion tube and are detected by the mass spectrometer filament. They are then extracted by the vacuum mechanism.

[0018] Step 5): While Step 3) and Step 4) are being performed, the sample in the reaction channel is characterized in situ using a Raman spectroscopy device or a UV-Vis DRS spectroscopy device.

[0019] A second aspect of the present invention provides a TAP-based Raman spectral coupling system, comprising the TAP-based extension device provided in the first aspect of the present invention, and a Raman spectral device. The Raman spectral device includes a laser, an external optical path unit, and a Raman spectrometer. The laser emits laser light, which sequentially passes through a first optical window, a first light-transmitting aperture, a second light-transmitting aperture, and a second optical window. Before hitting the sample, the laser forms an incident laser path; after hitting the sample, it is reflected by the sample and forms a reflected laser path, which is received by the Raman spectrometer. The external optical path unit system includes a beam expander, a reflecting mirror, a beam splitter, an ultra-long focal length objective, a filter, and a first focusing mirror. The beam expander, reflecting mirror, beam splitter, and ultra-long focal length objective are sequentially located in the incident laser path along the incident direction of the laser. The ultra-long focal length objective, beam splitter, filter, and first focusing mirror are sequentially located in the reflected laser path along the direction in which the laser is reflected. An external optical path adjustment mechanism is also provided below the external optical path unit system.

[0020] A third aspect of this invention provides a TAP-based UV-Vis DRS spectral coupling system, comprising the TAP-based extension device provided in the first aspect of this invention, and a UV-Vis DRS device. The UV-Vis DRS device includes a xenon lamp source, a reflective fiber optic probe, a focusing lens, and a UV-Vis DRS spectrometer. The xenon lamp source emits xenon light, which passes sequentially through a first optical window, a first light aperture, a second light aperture, and a second optical window. Before hitting the sample, the xenon lamp forms an incident light path; after hitting the sample, it is reflected by the sample, forming a reflected light path. The reflected light path is received by the UV-Vis DRS spectrometer. The reflective fiber optic probe and the focusing lens are sequentially located in the incident light path along the incident direction of the xenon lamp. The focusing lens, the reflective fiber optic probe, and the UV-Vis DRS spectrometer are sequentially located in the reflected light path along the direction in which the xenon lamp is reflected.

[0021] The TAP-based extension device, TAP-based Raman spectral coupling system, and TAP-based UV-Vis DRS spectral coupling system provided by this invention have the following beneficial effects:

[0022] 1) By coupling the TAP-based extension device with a Raman spectroscopy device or a UV-Vis DRS spectroscopy device, this invention enables simultaneous characterization of the structure and chemical properties of the active sites / active components of a sample under in-situ and near-operational conditions.

[0023] 2) The second optical window in this invention is a planar optical window and is integrally formed with the integrated reaction tube, which reduces the optical distortion that may be introduced by the curved tube wall, thus affecting the accuracy and reproducibility of the Raman & UV-Vis DRS signal, thereby improving the signal strength and resolution. The integrated design of the second optical window and the integrated reaction tube can avoid the use of vacuum sealing rings or sealants for sealing, will not change the gas diffusion path in the reaction channel, will not affect the accuracy of TAP experimental data, and can withstand higher temperatures, achieving a reaction temperature of room temperature to 850°C.

[0024] 3) The first light window, the first light-transmitting hole, the second light-transmitting hole, and the second light window in this invention enable the laser or xenon lamp to be successfully focused onto the sample surface in the reaction channel, while ensuring that the signal collection angle α of the Raman & UV-Vis DRS is 20 to 50°. This maximizes the receiving angle of the scattered light while meeting the shape requirements of the microreactor, and avoids background interference and uneven sample temperature caused by excessive opening angle.

[0025] 4) The pulse flange in this invention is equipped with a water cooling channel, which can cool down the sealing ring between the pulse flange and the integrated reaction tube, and can maintain excellent sealing performance when the temperature of the integrated reaction tube is as high as 850°C.

[0026] 5) The Raman spectrometer used in this invention uses an ultra-long focal length objective lens, while the UV-Vis DRS spectrometer uses a reflective fiber optic probe with a focusing lens. With the special design of the vacuum chamber and microreactor, it can overcome the spatial limitations of the vacuum chamber and be placed outside the vacuum chamber for in-situ spectral testing. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0028] Figure 2 This is a partial structural schematic diagram of the TAP-based extension device in this invention.

[0029] Figure 3 This is a schematic diagram of the microreactor in this invention.

[0030] Figure 4 This is a top view of the overall structure of the present invention.

[0031] Figure 5 This is a schematic diagram of the Raman spectrometer in this invention.

[0032] Figure 6 This is a schematic diagram of the UV-Vis DRS device in this invention.

[0033] Figure 7 This is the logic control diagram of the host computer in this invention.

[0034] Figure Labels

[0035] Vacuum cavity 1

[0036] First Light Window 11

[0037] Pulse Mechanism 2

[0038] Pulse flange 21

[0039] Pulse valve 22

[0040] Thermocouple connector 23

[0041] Heating wire connector 24

[0042] Water cooling aisle 25

[0043] Sealing ring 26

[0044] Vacuum mechanism 3

[0045] First molecular pump 31

[0046] Second molecular pump 32

[0047] Mechanical pump 33

[0048] Vacuum gauge 34

[0049] Thermal insulation shielding cavity 4

[0050] First light-transmitting aperture 41

[0051] Heating sleeve 5

[0052] Second light-transmitting aperture 51

[0053] Heating wire 52

[0054] Thermocouple 53

[0055] Integrated reaction tube 6

[0056] Reaction channel 61

[0057] Second light window 62

[0058] Expansion tube 63

[0059] Filter 64

[0060] Mass spectrometry 7

[0061] Mass spectrometer filament 71

[0062] Raman Spectrometer 8

[0063] Laser 81

[0064] External optical path unit 82

[0065] Beam expander 82.1

[0066] Mirror 82.2

[0067] Super telephoto objective lens 82.3

[0068] Filter 82.4

[0069] First focusing lens 82.5

[0070] Beam splitter 82.6

[0071] Raman Spectrometer 83

[0072] External optical path adjustment mechanism 84

[0073] UV-Vis DRS device 9

[0074] Xenon lamp light source 91

[0075] 92 reflective fiber optic probe

[0076] Second focusing lens 93

[0077] UV-Vis DRS Spectrometer 94 Detailed Implementation

[0078] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. In the description of the present invention, it should be noted that the terms "left side", "right side", "upper side", "lower side", "above", "below", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0079] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0080] Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0081] This invention provides a TAP-based expansion device, see below. Figure 1 The TAP-based extension device includes a vacuum chamber 1, with a pulse mechanism 2 at the top and a vacuum mechanism 3 at the bottom. The pulse mechanism 2 can introduce 0.01–10 nmol of trace reactive gas into the vacuum chamber 1, and the vacuum mechanism 3 can evacuate the inner cavity of the vacuum chamber 1 and maintain the vacuum level of the inner cavity of the vacuum chamber 1 at 10 nmol. -7 ~10 -10In general, the vacuum mechanism 3 also includes a vacuum gauge 34 disposed in the side wall of the vacuum chamber 1. The vacuum gauge 34 can detect the vacuum level in the vacuum chamber 1 to ensure that the vacuum level meets the experimental requirements. (Continue reading...) Figure 2 and Figure 3 The vacuum chamber 1 contains a microreactor, which includes a heat-insulating shielded cavity 4. An integrated reaction tube 6 is located within the heat-insulating shielded cavity 4, and a reaction channel 61 is provided within the integrated reaction tube 6. The pulse outlet of the pulse mechanism 2 is connected to the air inlet of the reaction channel 61, and the reaction channel 61 is suitable for placing a sample. (Continue reading...) Figure 2 and Figure 3 A heating sleeve 5 surrounds the outer wall of the integrated reaction tube 6. The function of the heating sleeve 5 is to heat the integrated reaction tube 6 to reach the reaction temperature. A first light window 11 is provided in the side wall of the vacuum chamber 1, a first light-transmitting hole 41 is provided in the side wall of the heat-insulating shielding cavity 4, a second light-transmitting hole 51 is provided in the side wall of the heating sleeve 5, and a second light window 62 is provided in the side wall of the integrated reaction tube 6. Generally, the centers of the first light window 11, the first light-transmitting hole 41, the second light-transmitting hole 51, and the second light window 62 are all located on the same straight line, which can be in the middle region of the vacuum chamber. As a supplement, the inner diameter of the heating sleeve 5 matches the outer diameter of the integrated reaction tube 6 so that the heating sleeve 5 can better transfer heat to the integrated reaction tube 6 during heating. In one specific embodiment, a vacuum sealing ring is provided between the first light window 11 and the side wall of the vacuum chamber 1, and the integrated reaction tube 6 and the second light window 62 are integrally formed. In another specific embodiment, see Figures 3-4 The first light window 11, the first light-transmitting hole 41, the second light-transmitting hole 51, and the second light window 62 are all present in pairs, forming two sets. However, only one set needs to be used during operation. In another specific embodiment, a filter 64 is also provided at the top of the integrated reaction tube 6. The filter 64 can prevent powder in the integrated reaction tube 6 from entering the pulse channel. Continue reading Figures 1-3The TAP-based extension device also includes a mass spectrometer 7. The mass spectrometer 7's mass spectrometer filament 71 passes through the side wall of the vacuum chamber 1 and enters the inner cavity of the vacuum chamber 1. An extension tube 63 is also provided at the outlet of the reaction channel 61. The extension tube 63 extends towards the mass spectrometer filament 71 but does not contact the mass spectrometer filament 71. Generally, the mass spectrometer 7 can be a high time resolution quadrupole mass spectrometer 7. As a supplement, a Raman spectroscopy device 8 or a UV-Vis DRS device 9 is usually placed outside the vacuum chamber 1. The laser emitted by the Raman spectroscopy device 8 or the xenon lamp emitted by the UV-Vis DRS device 9 passes sequentially through the first light window 11, the first light aperture 41, the second light aperture 51, and the second light window 62 and hits the sample surface. The Raman scattering signal reflected back from the sample is collected and analyzed by the Raman spectroscopy device 8, and the xenon lamp reflected back from the sample is collected and analyzed by the UV-Vis DRS device 9. In a typical experiment, only a TAP-based Raman spectral coupling system or a TAP-based UV-Vis DRS coupling system is selected. This invention, by coupling a TAP-based extension device with either a Raman spectral device 8 or a UV-Vis DRS spectral device 9, enables simultaneous characterization of the structure and chemical properties of active sites / active components in samples under in-situ and near-operational conditions. Embodiment 1 of this invention provides a TAP-based Raman spectral coupling system, and Embodiment 2 provides a TAP-based UV-Vis DRS coupling system.

[0082] In the TAP-based extension device provided in this embodiment of the invention, the diameter of the first light-transmitting aperture 41 is 5-30 mm, preferably 10-20 mm; the diameter of the second light-transmitting aperture 51 is 5-30 mm, preferably 10-20 mm; the first light window 11 is a planar light window with a diameter of 20-70 mm, preferably 23-40 mm; the second light window 62 is a planar light window with a thickness of 2-5 mm, preferably 2-3 mm; the height of the second light window 62 is 5-20 mm, preferably 5-10 mm; and the width of the second light window 62 is 2-12 mm, preferably 4-8 mm. It is worth noting that the collection angle α of the Raman signal reflected by the sample or the signal from the xenon lamp is 20-50°, preferably 30°. For details on the signal collection angle α, please refer to [link to relevant documentation]. Figure 2Because of the arrangement of the first light window 11, the first light-transmitting hole 41, the second light-transmitting hole 51, and the second light window 62, the Raman signal reflected by the sample or the scattered light from the xenon lamp that is greater than the signal collection angle α will be blocked by the integrated reaction tube 6, the heating sleeve 5, and the thermal insulation shielding cavity 4, thus preventing it from continuing to propagate outward. The second light window in this invention is a planar window and is integrally formed with the integrated reaction tube, reducing optical distortion that may be introduced by the curved tube wall, which would affect the accuracy and reproducibility of the Raman & UV-Vis DRS signal, thereby improving the signal strength and resolution. The integrated design of the second light window and the integrated reaction tube avoids the need for vacuum sealing rings or sealants, does not change the gas diffusion path in the reaction channel, does not affect the accuracy of TAP experimental data, and can withstand higher temperatures, achieving a reaction temperature range of room temperature to 850°C. Furthermore, the first light window 11, the first light-transmitting aperture 41, the second light-transmitting aperture 51, and the second light window 62 in this invention enable the laser or xenon lamp to be successfully focused onto the sample surface in the reaction channel 61, while ensuring that the signal collection angle α of the Raman & UV-Vis DRS is 20 to 50°. This maximizes the receiving angle of the scattered light while meeting the shape requirements of the microreactor, and avoids background interference and uneven sample temperature caused by excessive opening angle.

[0083] In a TAP-based expansion device provided in this embodiment of the invention, the vacuum degree of the vacuum chamber 1 is 10. -7 ~10 -10 mbar; and / or, the materials of the first light window 11 and the second light window 62 are both independently selected from fused silica glass or synthetic sapphire, preferably synthetic sapphire; and / or, the transmittance of the first light window 11 and the second light window 62 for 220-2000nm light is ≥90%; and / or, the length of the integrated reaction tube 6 is 30-100mm, preferably 40-60mm; and / or, the diameter of the reaction channel 61 is 3-6mm, preferably 4mm; and / or, the distance between the expansion tube 63 and the mass spectrometer filament 71 is 2-10mm, preferably 2-5mm; and / or, the material of the heating sleeve 5 is stainless steel.

[0084] In the TAP-based extension device provided in the embodiments of the present invention, see... Figure 3The outer wall of the heating sleeve 5 is provided with a plurality of heating wire grooves arranged sequentially along the axial direction of the heating sleeve 5. Each heating wire groove is provided with a heating wire 52. The outer wall of the heating sleeve 5 is also provided with a thermocouple groove extending along the axial direction of the heating sleeve 5. The thermocouple groove extends to a position close to the sample. The thermocouple groove is provided with a thermocouple 53. The thermocouple 53 is used to detect whether the heating sleeve 5 has been heated to the temperature required for the experiment. The thermocouple 53 is preferably a K-type thermocouple. For reference, the heating range of the heating wire 52 is room temperature to 1000°C.

[0085] In the TAP-based extension device provided in the embodiments of the present invention, see... Figure 2 and Figure 3 The pulse mechanism 2 includes a pulse flange 21 connected to the top of the vacuum chamber 1. A pulse valve 22 is provided in the pulse flange 21, and the outlet of the pulse valve 22 is connected to the air inlet of the reaction channel 61. The pulse flange 21 is also provided with a thermocouple connector 23 and a heating wire connector 24. The thermocouple connector 23 is connected to a thermocouple 53, and the heating wire connector 24 is connected to a heating wire 52. A sealing ring 26 is also provided between the pulse flange 21 and the integrated reaction tube 6. A water cooling channel 25 is also provided in the pulse flange 21. The water cooling channel 25 is used to cool the sealing ring 26, which can maintain excellent sealing performance when the temperature of the integrated reaction tube 6 reaches 850°C. The sealing ring 26 can be a high-temperature resistant O-ring.

[0086] In the TAP-based extension device provided in the embodiments of the present invention, see... Figure 1 The vacuum mechanism 3 includes a first molecular pump 31, a second molecular pump 32, and a mechanical pump 33 connected in sequence. The first molecular pump 31 is connected to the inner cavity of the vacuum chamber 1. For illustration, the pumping speed of the first molecular pump 31 is ≥300 L / s, and the pumping speed of the second molecular pump 32 is 15–85 L / s. The series connection of these three pumps enables the vacuum level of the vacuum chamber 1 to be maintained at 10. -7 ~10 -10 mbar.

[0087] In the TAP-based extension device provided in the embodiments of the present invention, see... Figure 7 It also includes a host computer, which is used to coordinate and control the pulse mechanism 2, mass spectrometer 7, Raman spectroscopy device 8 and UV-Vis DRS device 9. For reference, both Raman spectroscopy device 8 and UV-Vis DRS device 9 include spectrometers, and the spectrometers in these two systems can, in principle, share one.

[0088] This invention also provides a method for using a TAP-based extension device, comprising the following steps:

[0089] Step 1): Vacuum chamber 1 is evacuated using vacuum mechanism 3 in the TAP-based extension device to maintain the vacuum level at 10. -7 ~10 -10 mbar.

[0090] Step 2): The microreactor in the TAP-based extension device is heated to the reaction temperature, and the sample also reaches the reaction temperature at the same time;

[0091] Step 3): Different micro-pulse reaction gases are injected into the reaction channel 61 through the pulse mechanism 2 in the TAP-based extension device, and react with the sample in the reaction channel 61.

[0092] Step 4): After the reactant gas reacts with the sample in Step 3, the unreacted reactant, reference gas and product gas molecules enter the vacuum chamber 1 through the expansion tube 63 and are detected by the mass spectrometer filament 71 of the mass spectrometer 7, and then are extracted by the vacuum mechanism 3.

[0093] Step 5): While Step 3) and Step 4) are being performed, the sample in the reaction channel 61 is characterized in situ using Raman spectroscopy device 8 or UV-Vis DRS spectroscopy device 9.

[0094] Example 1: A TAP-based Raman spectral coupling system

[0095] This invention provides a TAP-based Raman spectral coupling system, see reference. Figure 5 The system also includes a Raman spectroscopy device 8, which comprises a laser 81, an external optical path unit 82, and a Raman spectrometer 83. The laser 81 emits laser light, which sequentially passes through a first optical window 11, a first light-transmitting aperture 41, a second light-transmitting aperture 51, and a second optical window 62. Before hitting the sample, the laser forms an incident light path; after hitting the sample, it is reflected by the sample, forming a reflected light path. This reflected light path is received by the Raman spectrometer 83. The wavelength of the laser emitted by the laser 81 is 257, 325, 532 nm, or 785 nm, which can be adjusted according to different experimental requirements. The external optical path unit 82 and the Raman spectrometer 83 are typically connected by optical fiber. (Continue reading...) Figure 5The external optical path unit 82 system includes a beam expander 82.1, a reflector 82.2, a beam splitter 82.6, an ultra-long focal length objective lens 82.3, a filter 82.4, and a focusing lens 93. The beam expander 82.1, reflector 82.2, beam splitter 82.6, and ultra-long focal length objective lens 82.3 are sequentially located in the laser incident optical path along the incident direction of the laser. The ultra-long focal length objective lens 82.3, beam splitter 82.6, filter 82.4, and focusing lens 93 are sequentially located in the laser reflection optical path along the direction in which the laser is reflected. For illustration, the laser emitted by the laser 81, after passing through the ultra-long focal length objective lens 82.3, continues to pass sequentially through the first optical window 11, the first light-transmitting aperture 41, the second light-transmitting aperture 51, and the second optical window 62, and strikes the reaction channel 61. The laser light reflected from the sample passes through the first optical window 11 and then sequentially through the ultra-long focal length objective lens 82.3, beam splitter 82.6, filter 82.4, and focusing lens 93 before reaching the Raman spectrometer 83 for detection. It is worth noting that in the laser incident light path, beam splitter 82.6 reflects the laser light and allows it to continue propagating to the ultra-long focal length objective lens 82.3, while in the laser reflection light path, beam splitter 82.6 allows the reflected laser light to pass directly through and continue propagating to the filter 82.4. For illustration, the working distance of the ultra-long focal length objective lens 82.3 is 100–200 mm, and the spot diameter of the laser light focused by the ultra-long focal length objective lens 82.3 is 5–20 μm. (Continue reading...) Figure 1 Below the external optical path unit 82 system, there is also an external optical path adjustment mechanism 84. The external optical path adjustment mechanism 84 can adjust the incident angle of the laser so that the size and position of the laser spot hitting the sample can meet the experimental requirements. In this embodiment, an ultra-long focal length objective lens 82.3 is used in conjunction with the special design of the vacuum chamber 1 and the microreactor, which can overcome the spatial limitations of the vacuum chamber 1 and be placed outside the vacuum chamber 1 for in-situ spectral testing.

[0096] Example 2: A TAP-based UV-Vis DRS spectral coupling system

[0097] This invention provides a TAP-based UV-Vis DRS spectral coupling system, see reference. Figure 6It also includes a UV-Vis DRS device 9, which comprises a xenon lamp source 91, a reflective fiber optic probe 92, a second focusing lens 93, and a UV-Vis DRS spectrometer 94. The xenon lamp source 91 emits xenon light, which passes sequentially through a first light window 11, a first light-transmitting aperture 41, a second light-transmitting aperture 51, and a second light window 62. Before hitting the sample, the xenon lamp forms an incident light path; after hitting the sample, it is reflected by the sample, forming a reflected light path. The reflected light path is received by the detector 94. The xenon lamp can cover wavelengths of 220–2000 nm, and the focused spot diameter of the xenon lamp is 0.3–3 mm. (Continue reading...) Figure 6 The reflective fiber optic probe 92 and the second focusing lens 93 are sequentially located in the xenon lamp incident light path along the incident direction of the xenon lamp. The second focusing lens 93, the reflective fiber optic probe 92, and the UV-Vis DRS spectrometer 94 are sequentially located in the xenon lamp reflection light path along the direction in which the xenon lamp is reflected. For illustration, the xenon lamp emitted by the xenon lamp source 91 passes through the second focusing lens 93 and then sequentially passes through the first light window 11, the first light aperture 41, the second light aperture 51, and the second light window 62, and hits the sample surface in the reaction channel 61. The xenon lamp reflected by the sample passes through the first light window 11 and then sequentially passes through the second focusing lens 93 and the reflective fiber optic probe 92, and hits the UV-Vis DRS spectrometer 94 for detection. It is worth noting that in the xenon lamp incident light path, the reflective fiber optic probe 92 is usually a Y-type reflective fiber optic probe 92, which can distinguish the xenon lamp incident light path and the xenon lamp reflection light path, so that the two do not interfere with each other. In this embodiment, a reflective fiber optic probe 92 and a second focusing mirror 93 are used in conjunction with the special design of the vacuum chamber 1 and the microreactor, which can overcome the spatial limitations of the vacuum chamber 1 and be placed outside the vacuum chamber 1 for in-situ spectral testing.

[0098] Example 3: TAP-based Raman spectral coupling experiment or TAP-based UV-Vis DRS spectral coupling experiment

[0099] Before testing: Vacuum mechanism 3 in the TAP-based extension device is used to evacuate the inner cavity of vacuum chamber 1, maintaining the vacuum level of the inner cavity of vacuum chamber 1 at 10. -7 ~10 -10 mbar. Then, the integrated reaction is heated to the reaction temperature using heating wire 52 and thermocouple 53 in the TAP-based extension device, while the sample also reaches the reaction temperature.

[0100] During testing: Pulse valve 22 continuously pulses a certain amount of gas molecules (such as H2 / Ar, CO2 / Ar, CO / Ar, CH4 / Ar, etc., with Ar as an inert reference gas). The number of molecules in a single pulse is 0.01–100 nmol (which needs to be much smaller than the number of sites on the sample surface). Mass spectrometry 7 and mass spectrometry filament 71 are used to detect the peak shape and area of ​​the pulse gas (containing unreacted reactants, inert reference gas, and products) at the outlet of the reaction tube, to study the reaction intermediates, active sites, transient kinetics, and microscopic mechanisms of chemical reactions related to the elementary reaction. At the same time, Raman spectroscopy device 8 is used to characterize the sample surface in situ during a single pulse, as well as the dynamic evolution of the sample's crystal phase structure, coordination and polymerization state, relative concentration of oxygen vacancies, and surface carbon as the number of pulses increases. Alternatively, UV-Vis DRS device 9 is used to characterize the dynamic evolution of the sample's band structure, surface adsorption, and the coordination state and oxidation state of surface transition metal ions in situ. Under precise, minute gas pulse conditions, the intrinsic microscopic kinetics of the reaction and the transient responses and changes in the active site structure during the reaction process are simultaneously detected. This allows for the study of the correlation between the catalyst active center structure, intermediate species, and intrinsic catalyst activity at the microscopic level, clarifying the key factors affecting catalytic performance and understanding the essence of the catalytic reaction. In this embodiment, a reflective fiber optic probe 92 and a focusing mirror 93 are used in conjunction with the special design of the vacuum chamber 1 and the microreactor, which can overcome the spatial limitations of the vacuum chamber 1 and allow in-situ spectroscopic testing outside the vacuum chamber 1.

[0101] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A TAP-based extension device, characterized in that: The TAP-based extension device includes a vacuum chamber (1), a pulse mechanism (2) at the top of the vacuum chamber (1), and a vacuum mechanism (3) at the bottom of the vacuum chamber (1); a micro reactor is provided in the inner cavity of the vacuum chamber (1). The microreactor includes a heat-insulating shielded cavity (4), an integrated reaction tube (6) is provided in the inner cavity of the heat-insulating shielded cavity (4), a reaction channel (61) is provided in the integrated reaction tube (6), the pulse outlet of the pulse mechanism (2) is connected to the air inlet of the reaction channel (61), and the reaction channel (61) is suitable for placing samples. The outer wall of the integrated reaction tube (6) is surrounded by a heating sleeve (5); the side wall of the vacuum cavity (1) is provided with a first light window (11), the side wall of the heat insulation shield cavity (4) is provided with a first light-transmitting hole (41), the side wall of the heating sleeve (5) is provided with a second light-transmitting hole (51), and the side wall of the integrated reaction tube (6) is provided with a second light window (62). The TAP-based expansion device also includes a mass spectrometer (7), the mass spectrometer filament (71) of which passes through the side wall of the vacuum chamber (1) and enters the inner cavity of the vacuum chamber (1). An expansion tube (63) is also provided at the outlet of the reaction channel (61), the expansion tube (63) extends toward the mass spectrometer filament (71) and does not contact the mass spectrometer filament (71).

2. The TAP-based extension device according to claim 1, characterized in that: The diameter of the first light-transmitting aperture (41) is 5-30 mm, the diameter of the second light-transmitting aperture (51) is 5-30 mm, the first light window (11) is a planar light window with a diameter of 20-70 mm; the second light window (62) is a planar light window with a thickness of 2-5 mm, a height of 5-20 mm, and a width of 2-10 mm; the signal collection angle α of the laser or xenon lamp reflected by the sample is 20-50°.

3. The TAP-based extension device according to claim 1, characterized in that: The vacuum level of the vacuum chamber (1) is 10. -7 ~10 -10 mbar; and / or, the materials of the first light window (11) and the second light window (62) are both independently selected from fused silica glass or artificial sapphire; and / or, the transmittance of the first light window (11) and the second light window (62) to 220-2000nm light is ≥90%; and / or, the length of the integrated reaction tube (6) is 30-100mm; and / or, the diameter of the reaction channel (61) is 3-6mm; and / or, the distance between the expansion tube (63) and the mass spectrometer filament (71) is 2-10mm; and / or, the material of the heating sleeve (5) is stainless steel; and / or, the vacuum mechanism (3) further includes a vacuum gauge 34 disposed in the side wall of the vacuum chamber (1); and / or, the top of the integrated reaction tube (6) is also provided with a filter screen (64).

4. The TAP-based extension device according to claim 1, characterized in that: The outer wall of the heating sleeve (5) is provided with a plurality of heating wire grooves arranged sequentially along the axial direction of the heating sleeve (5), and each heating wire groove is provided with a heating wire (52); the outer wall of the heating sleeve (5) is also provided with a thermocouple groove extending along the axial direction of the heating sleeve (5), the thermocouple groove 53 extends to a position close to the sample, and the thermocouple groove 53 is provided with a thermocouple (53).

5. The TAP-based extension device according to claim 1, characterized in that: The pulse mechanism (2) includes a pulse flange (21) connected to the top of the vacuum chamber (1); a pulse valve (22) is provided in the pulse flange (21), and the outlet of the pulse valve (22) is connected to the air inlet of the reaction channel (61); a thermocouple connector (23) and a heating wire connector (24) are also provided in the pulse flange (21), the thermocouple connector (23) is connected to the thermocouple (53), and the heating wire connector (24) is connected to the heating wire (52); a water cooling channel (25) is also provided in the pulse flange (21); a sealing ring (26) is also provided between the pulse flange (21) and the integrated reaction tube (6).

6. The TAP-based extension device according to claim 1, characterized in that: The vacuum system includes a first molecular pump (31), a second molecular pump (32), and a mechanical pump (33) connected in sequence; the first molecular pump (31) is connected to the inner cavity of the vacuum chamber (1).

7. The TAP-based extension device according to claim 1, characterized in that: It also includes a host computer, which is used to coordinate and control the pulse mechanism (2), mass spectrometer (7), Raman spectrometer (8) and UV-Vis DRS device (9).

8. A method of using a TAP-based extension device as described in any one of claims 1 to 7, comprising the following steps: Step 1): The vacuum chamber (1) is evacuated using the vacuum mechanism (3) in the TAP-based extension device to maintain the vacuum level at 10. -7 ~10 -10 mbar; Step 2): The microreactor in the TAP-based extension device is heated to the reaction temperature, and the sample also reaches the reaction temperature at the same time; Step 3): Different trace amounts of reactive gas are pulsed into the reaction channel (61) by the pulse mechanism (2) in the TAP-based extension device and react with the sample in the reaction channel (61); Step 4): After the reactant gas reacts with the sample in Step 3, the unreacted reactant, reference gas and product gas molecules enter the vacuum chamber (1) along the expansion tube (63) and are detected by the mass spectrometer filament (71) of the mass spectrometer (7), and then are extracted by the vacuum mechanism (3). Step 5): While Step 3) and Step 4) are being performed, the sample in the reaction channel (61) is characterized in situ using a Raman spectrometer (8) or a UV-Vis DRS spectrometer (9).

9. A TAP-based Raman spectral coupling system, comprising the TAP-based extension device as described in any one of claims 1 to 7, characterized in that: It also includes a Raman spectroscopy device (8), which includes a laser (81), an external optical path unit (82), and a Raman spectrometer (83). The laser (81) is used to emit laser light. The laser light passes through a first optical window (11), a first light-transmitting aperture (41), a second light-transmitting aperture (51), and a second optical window (62) in sequence. Before the laser light hits the sample, it forms a laser incident light path. After hitting the sample, the laser light is reflected by the sample and forms a laser reflected light path. The laser reflected light path is received by the Raman spectrometer (83). The external optical path unit (82) includes a beam expander (82.1), a reflector (82.2), a beam splitter (82.6), an ultra-long focal length objective (82.3), a filter (82.4), and a first focusing lens (82.5); the beam expander (82.1), the reflector (82.2), the beam splitter (82.6), and the ultra-long focal length objective (82.3) are located sequentially in the laser incident optical path along the incident direction of the laser; the ultra-long focal length objective (82.3), the beam splitter (82.6), the filter (82.4), and the first focusing lens (82.5) are located sequentially in the laser reflection optical path along the direction in which the laser is reflected; an external optical path adjustment mechanism (84) is also provided below the external optical path unit (82).

10. A TAP-based UV-Vis DRS spectral coupling system, comprising the TAP-based extension device as described in any one of claims 1 to 7, characterized in that: It also includes a UV-Vis DRS device (9), which includes a xenon lamp light source (91), a reflective fiber optic probe (92), a focusing lens (93) and a UV-Vis DRS spectrometer (94). The xenon lamp light source (91) is used to emit xenon light. The xenon light passes through a first light window (11), a first light-transmitting aperture (41), a second light-transmitting aperture (51) and a second light window (62) in sequence. Before the xenon light hits the sample, it forms an incident light path. After hitting the sample, it is reflected by the sample and forms a reflected light path. The reflected light path is received by the UV-Vis DRS spectrometer (94). The reflective fiber optic probe (92) and the focusing lens (93) are located sequentially in the incident optical path of the xenon lamp along the incident direction of the xenon lamp; The focusing lens (93), the reflective fiber optic probe (92), and the UV-Vis DRS spectrometer (94) are located sequentially in the xenon lamp reflection path along the direction in which the xenon lamp is reflected.

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