Capillary mass spectrum sampling device for spatially distinguishing sampling points

Abstract

The invention provides a spatial resolution sampling point capillary mass spectrum sampling device which is characterized by comprising a reaction generation unit, a capillary mass spectrum sampling unit and a movable sealing unit. In the invention, the inventor provides a scheme for lifting a static mass spectrum sampling point into a dynamic mass spectrum sampling point, continuously moving and accurately controlling the position, so that the material activity analysis of spatial resolution is realized. According to the invention, high time resolution, high mass number resolution, high component sensitivity and high spatial resolution of a mass spectrum can be combined, and an application space, such as an in-situ spectrum technology, an isotopic tracer technology, a steady-state isotope transient dynamics analysis technology and the like, can be provided for use with other structurally sensitive spectrum technologies. In scientific research, the real-time structure-function relationship of a real site can be provided, and material attributes can be understood.

Description

Technical Field

[0001] The invention relates to a mass spectrometry sampling device. Background Art

[0002] In-depth study of reaction kinetics is of great significance for guiding catalyst improvement, optimizing reaction conditions and revealing the internal mechanism of catalytic reactions. However, due to the limitations of experimental techniques and theoretical models, the understanding of reaction kinetics still faces many challenges. When studying catalytic reactions, reaction performance is a key indicator. At present, the common reaction generator is a continuous plug flow reactor, such as a fixed bed structure tubular furnace. The collection point of the product signal is connected to the tail gas pipe of the catalyst bed, that is, the reaction mixture is input into the reactor, and the output after passing through the catalyst bed is collected and analyzed by the detector. Therefore, the gas concentration result after the catalyst bed is obtained. By comparing the changes in the species import and export signals, kinetic information such as conversion rate, yield, and reaction rate can be obtained. However, in this traditional analysis method, by monitoring the input amount of reactants and the output amount of products, only the reaction rate in the entire catalyst bed can be determined, and the gas composition at different positions of the catalyst during the reaction process cannot be obtained, and it is difficult to directly gain insight into the intrinsic mechanism of the catalyst. In addition, in the species analysis in near-normal pressure and vacuum environments, mass spectrometry acquisition, as a means of main component analysis, also has only one or several fixed sampling points, and cannot collect gas component information associated with different positions on the material surface. In previous patents, the inventors have designed real-time sampling schemes for the ultra-high vacuum working analysis environment of mass spectrometry using capillary sampling technology, respectively, within normal pressure to 20 atmospheres, below 200 atmospheres, and near-normal pressure of 0.1 mbar. The previous normal pressure collection has been expanded to fully cover the range of 0.1 mbar-200 atmospheres, thereby extending the chemical analysis application of online mass spectrometry to all pressure ranges required for the reaction. Summary of the invention

[0003] The technical problem to be solved by the present invention is that the collection point of the traditional mass spectrometry sampling device is at a fixed position, such as the tail gas pipe after the catalyst bed, and what is obtained is the gas concentration signal after the reaction, which is the result of the accumulation or average of the gas concentrations at all spatial positions in the collection area, and cannot reflect the distribution of gas signals in the entire space, such as the kinetic information associated with the spatial distribution.

[0004] In order to solve the above technical problems, the technical solution of the present invention is to disclose a spatial resolution sampling point capillary mass spectrometry sampling device, characterized in that it includes a reaction generating unit, a capillary mass spectrometry sampling unit and a movable sealing unit, wherein:

[0005] The movable sealing unit is located between the capillary mass spectrometer sampling unit and the reaction unit, and is a three-way structure having port one, port two and port three, wherein port one is directly connected to port two, port one is fixedly connected to the tail gas interface at the outlet end of the reaction unit, and port three is the tail gas discharge port, which is compatible with the normal tail gas discharge of the reaction unit;

[0006] The capillary mass spectrometry sampling unit includes a capillary sampling tube, a zero dead volume valve and a driving unit. The capillary sampling tube is connected to the mass spectrometer device through the zero dead volume valve. At the same time, the capillary sampling tube passes through port 2 of the movable sealing unit and directly enters the interior of the reaction unit through the port. The N-axial space control of the capillary sampling tube is realized by the driving unit, N≥1, so that the part of the capillary sampling tube inside the reaction unit moves relative to the reaction unit. During the movement, the sampling position of the capillary sampling tube is synchronized with the position marked by the driving unit, and the movement range of the part of the capillary sampling tube inside the reaction unit can pass through the spatial range where the material in the reaction unit is located.

[0007] Preferably, the reaction generating unit comprises a reactor arranged on a support platform 1, and the reactor is provided with a heating and cooling module controlled by a temperature controller.

[0008] Preferably, the reactor adopts a quartz tube with a diameter of 5 mm and a length of 80 mm, and the reaction system adopts a methane oxidative coupling reaction in which the temperature requirement in the chemical reaction is >800°C.

[0009] Preferably, the capillary mass spectrometry sampling unit further comprises a straight-through fixed joint and a second support platform, the capillary sampling tube is fixed to the second support platform via the straight-through fixed joint, and the driving unit drives the capillary mass spectrometry sampling unit to move as a whole via the second support platform.

[0010] Preferably, the straight-through fixed joint serves as a relay support between the movable sealing unit and the zero dead volume valve when the ratio of the length to the diameter of the capillary sampling tube is large.

[0011] Preferably, an O-ring is used to seal between the capillary sampling tube and port one and port two of the movable sealing unit, and the static friction between the O-ring and the capillary sampling tube is smaller than the friction of the fixed seal between the capillary sampling tube and the straight-through fixed joint and / or the zero dead volume valve.

[0012] Preferably, a method of stacking and packaging a plurality of the O-rings is adopted.

[0013] Preferably, the second support platform is leveled by a fine two-dimensional surface to precisely align the axial direction of the capillary sampling tube with the axis of the reactor fixed on the first support platform.

[0014] Preferably, the reaction generating unit, the capillary mass spectrometry sampling unit and the movable sealing unit are integrated on an aluminum alloy bottom plate.

[0015] Preferably, a gas-solid catalytic system is used and continuous signal acquisition is tested.

[0016] In the present invention, the inventor proposes a scheme to upgrade the static mass spectrometry sampling point to a dynamic one that can be continuously moved and precisely controlled in position, so as to realize spatially resolved material activity analysis. The present invention can combine the high time resolution, high mass number resolution, high component sensitivity and high spatial resolution of mass spectrometry, and can provide application space for use with other structure-sensitive spectroscopy techniques, such as in-situ spectroscopy, isotope tracing technology, steady-state isotope transient kinetic analysis technology, etc., and can provide real-time structure-activity relationship of real sites in scientific research and understand material properties.

[0017] Compared with the prior art solutions, the present invention has the following characteristics:

[0018] ① In-situ spectroscopy technology can monitor the chemical state and structural changes of the catalyst surface in real time under simulated actual industrial conditions, and directly provide information related to the catalyst surface, reaction intermediates, etc. There is no need to transfer the catalyst for analysis, thus avoiding possible changes in the catalyst during the transfer process. Combined with spatially resolved mass spectrometry technology, it can effectively correlate the structural information of the spectrum with the activity information at different sites of the material, greatly enhancing the depth of understanding of the working mechanism of the material.

[0019] ② Isotope tracing technology uses labeled isotopes (such as 13 C. 18 O, etc.) to track the conversion process of reactants on the catalyst surface. It can perform multiple measurements without destroying the sample, and can also detect extremely small amounts of substances with high sensitivity and accuracy. This method requires expensive isotope markers and specialized equipment, and the cost of repeated experiments is high. Mass spectrometry technology itself has a high isotope sensitivity. Combined with spatial resolution, it can obtain information on the spatial distribution and diffusion process of isotopes in the material at one time, thereby truly realizing isotope tracing, improving the efficiency of related experiments, and reducing isotope costs.

[0020] ③ Steady-state isotope transient kinetic analysis (SSITKA) is to monitor the subsequent changes in product isotope distribution by switching isotopes under stable reaction conditions. This technology can study the dynamic behavior of catalysts under conditions close to the actual reaction conditions and obtain information about the active sites on the catalyst surface, reaction intermediates, etc. Combined with spatially resolved mass spectrometry technology, it can also double the amount of information in related experiments and reduce the experimental cycle.

[0021] In terms of application, the present invention can improve the monitoring capability of materials and systems at work, and provide more effective control feedback or safety diagnosis of the reaction system through the spatial real-time distribution information of the product. The mass spectrometry method currently used to explore the dynamic behavior of catalysts is undoubtedly a powerful tool to reveal its internal mechanism. Related technologies such as further realizing spatial resolution can improve the application space of high-precision equipment, expand the amount of collected information, and facilitate strict environmental control, specific sample preparation, and more professional operation, etc., which are more suitable for the changing industrial production environment in the future.

[0022] The present invention innovates the existing fixed-point mass spectrometry sampling device, and connects the inside and outside of the material working space through a movable capillary sampling unit, which can accurately capture its local transient gas components while the material is working stably, thereby realizing comprehensive monitoring of different sites of the material working process. The present invention proposes a specific axial (i.e., from the entrance to the exit of the working space) sampling scheme, and can be expanded to include radial (i.e., from the center of the working space to the wall) spatial resolution sampling. The present invention can realize full-scale mass spectrometry acquisition in a confined space, such as analyzing the gas components at different positions of the catalyst bed during the reaction process, so as to obtain the spatial distribution information of the corresponding species, and the sampling unit can set the moving rate according to the needs of the user. At the same time, the sampling of the present invention is not affected by the temperature of the environmental sampling point within 1000°C, and can work stably in a high temperature environment. The present invention is of great significance for expanding the scientific and practical applications of mass spectrometry, such as reaction catalysis mechanism, gas detection, etc. The device disclosed in the present invention can characterize the activity of different positions of the material object and can be used in conjunction with other structure-sensitive spectroscopy techniques, such as X-ray diffractometer (XRD), infrared analysis (IR), etc., to provide real-time structure-activity relationship of real sites. The present invention has the characteristics of simple structure, high cost-effectiveness, and the ability to meet the requirements of complex industrial environment simulation. It has the potential for popularization in practical applications, and also provides an innovative solution strategy for common problems in traditional steady-state analysis processes.

[0023] In summary, the device disclosed in the present invention has the following main advantages compared with the existing technical solutions:

[0024] (1) It can provide millimeter-level spatial resolution and accurately capture the reaction kinetics information of the catalyst in each micro-region;

[0025] (2) It can realize real-time spatially resolved acquisition and is compatible with the advantages of mass spectrometry component analysis in time resolution, trace content sensitivity, and molecular weight sensitivity;

[0026] (3) The capillary mass spectrometry sampling unit is easy to disassemble and carry, has strong compatibility, and can be used with a variety of reactors and analysis platforms to obtain spatially resolved information on the working state of the material;

[0027] (4) Small size and low sampling volume, which does not affect the normal operation of the material and the working space structure of the reactor;

[0028] (5) Ability to simulate industrial high-temperature reaction environment;

[0029] (6) The device is simple, easy to assemble, and has a low manufacturing cost, making it easy to promote and use widely. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The spatially resolved capillary sampling device of the present invention is illustrated;

[0031] Figure 2 It is a front view of the reaction generating unit in the present invention;

[0032] Figure 3 The figure shows the real-time mass spectrometry data of mobile sampling in the 800℃ OCM reaction, including the reactant CH4 (left coordinate) and the product C2 (right coordinate). The upper horizontal coordinates 0 / 1 / 2 / 3 / 4 / 5 / 6 / 7mm are the relative positions of the capillary sampling point and the catalyst, among which 0mm is the starting position of the Mn-Na2WO4 / SiO2 catalyst bed. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0034] The technical problems to be solved by a spatially resolved sampling point capillary mass spectrometry sampling device disclosed in an embodiment of the present invention include:

[0035] Question 1: The airtightness of the mobile sampling point in the material working space, that is, except for a small amount of reaction gas being sampled, all the reaction gases are in the original working space, no leakage occurs during the movement of the sampling point, and the original reaction state is retained throughout the process without being disturbed by the sampling process;

[0036] Problem 2: The ability to accurately move the sampling point with high spatial resolution;

[0037] Question 3: Realize the real-time connection between the high temperature and high pressure environment of the sampling point and the working environment of the mass spectrometer, that is, the 0.1mbar to 200bar environment to the mass spectrometer working environment 10 -8 -10 -5 Direct sampling of mbar;

[0038] Question 4: The sampling point interface should be miniaturized to minimize the impact on the original structure of the sampling workspace and reduce the interference of sampling on the reaction process. For example, in catalytic research, a microreactor with a diameter of only a few millimeters is used. Sampling structures larger than this scale will affect the original airflow distribution in the workspace and the contact with the catalyst.

[0039] Question 5: Cost control: reduce the cost of equipment and components increased by spatial resolution acquisition to a controllable range.

[0040] In response to the above problems, the inventors proposed a patented capillary sampling scheme (ZL201610140435.5, ZL201710094416.8, 202410220463.2) before. The sampled fluid is directly transported to the mass spectrometer for analysis, which can directly solve the third problem. The capillary is connected to the linear drive to achieve continuous forward and reverse translation along the axial direction of the reaction gas flow under steady-state conditions in the reaction space, and atomic-level translation accuracy can be achieved. Thereby, high spatial resolution distribution information including kinetic information such as substance type, proportion, partial pressure, etc. is obtained (question 2). On this basis, the inventor adopts a special sealing scheme to ensure that while spatially resolving sampling, the mobile sampling device does not affect the independent operation of the gas inside the working space (question 1). All device-related components are miniaturized, the relevant scale is reduced to the order of magnitude of the capillary diameter, and the volume effect of the sampling device on the working space is basically consistent with the ratio between the sampling amount and the reaction gas input amount, ensuring that the influence of the sampling device structure on the original volume and structure of the working space can be ignored. Finally, according to the design requirements, the parts are purchased and assembled in a suitable cost space, while meeting the quality requirements and ensuring cost control. The device disclosed in the present invention still retains the excellent time resolution capability of the mass spectrometer, and can quickly detect ppb-ppm level changes in the working environment atmosphere, such as the deactivation trend of the catalyst. The device disclosed in the present invention can also be combined with advanced characterization technology to perform spatially resolved spectral analysis of the structure of the material under working conditions, providing a powerful tool for the study of chemical reaction kinetics.

[0041] Figure 1 The layout design concept of the device disclosed in the present invention is demonstrated, which is composed of three core conceptual units (dashed boxes): a reaction unit 1, i.e. the aforementioned material reaction space; a capillary mass spectrometer sampling unit 2 moving axially along the reaction unit 1; and a movable sealing unit 3 connecting the above two parts.

[0042] The key components of the reaction unit 1 may include, but are not limited to, a reactor 1.1, a heating and cooling module 1.2, a temperature controller 1.3, and a customized support stand 1.4. The enlarged conceptual diagram thereof is shown in FIG. Figure 2As shown, the temperature control part is not in the figure. The temperature controller 1.3 further includes a temperature detection device and a temperature control device. The temperature detection device is usually placed between the heating and cooling module 1.2 and the reactor 1.1. A preferred embodiment is that in order to reduce the volume inside the device and improve its heat resistance and reaction inertness, the reactor 1.1 adopts a quartz tube with a diameter of 5mm and a length of 80mm; the reaction system adopts a methane oxidative coupling reaction with high temperature requirements (>800℃) in chemical reactions.

[0043] The capillary mass spectrometry sampling unit 2 is composed of a capillary sampling tube 2.1, a straight-through fixed joint 2.2, a zero dead volume valve 2.3, a support platform 2.4 and a linear drive unit 2.5. The support platform 2.4 is fixedly connected to the straight-through fixed joint 2.2, the zero dead volume valve 2.3 and the linear drive unit 2.5 to ensure that the relative positions of the above components remain unchanged. The capillary sampling tube 2.1 is also fixedly connected to the straight-through fixed joint 2.2 and the zero dead volume valve 2.3, so the position of the capillary sampling tube 2.1 and the rest of the capillary mass spectrometry sampling unit 2 also remains fixed. For the spatial position control of the capillary sampling tube 2.1, the embodiment of the present invention is only illustrated with unidirectional movement. In actual applications, those skilled in the art can also achieve multi-axial spatial control through multi-axial linear drive coupling links. In the embodiment of the present invention, the linear drive unit 2.5 under the support table moves axially to drive the capillary mass spectrometry sampling unit 2 to move as a whole, while the reaction unit 1 remains stationary, thereby realizing the relative movement of the portion of the capillary sampling tube 2.1 inside the reactor 1.1 and the reaction unit 1. The movable sealing unit 3 is located between the reaction unit 1 and the capillary mass spectrometry sampling unit 2, and adopts a three-way structure, one end of which is directly connected to the exhaust gas interface at the outlet end of the reactor 1.1, and the other port directly connected to this end is connected to the capillary sampling tube 2.1, that is, the capillary sampling tube 2.1 directly enters the reactor 1.1 from this end, and the linear drive unit 2.5 ensures that its movement range can pass through the spatial range where the material is located, such as the surface of a planar block material or the filling space of a powder material. In order to ensure the movement and sealing of the capillary sampling tube 2.1 inside the reactor 1.1, the embodiment of the present invention adopts a design strategy based on friction difference, that is, the capillary sampling tube 2.1 and the port of the three-way structure are sealed with an O-ring of special material, and the static friction between the capillary sampling tube 2.1 and the capillary sampling tube 2.1 is less than the friction of the fixed seal between the capillary sampling tube 2.1 and the straight-through fixed joint 2.2 and the zero dead volume valve 2.3. This design ensures that when the capillary mass spectrometry sampling unit 2 moves as a whole with the support platform 2.4 and the linear drive unit 2.5, the capillary sampling tube 2.1 can stably follow the capillary mass spectrometry sampling unit 2 and slide relative to the movable sealing unit 3, thereby achieving the purpose of accurate point sampling. During the movement, the sampling position of the capillary sampling tube 2.1 is synchronized with the position marked by the linear drive unit 2.5, so the precise displacement of the linear drive unit 2.5 can be used to calibrate the relative displacement of the capillary sampling tube 2.1. The vertical end 3.1 of the three-way structure of the movable sealing unit 3 is used as an exhaust gas discharge port, which is compatible with the normal exhaust gas discharge of the reactor 1.1. Different from the fixed mass spectrometer sampling port, the sampling port of the present invention adopts a straight-through connection and a sealing design that allows sliding, ensuring the free movement of the capillary sampling tube 2.1 inside the reactor 1.1.A preferred implementation is that, in order to ensure that the capillary sampling tube 2.1 can move smoothly for sampling, the bracket 2.4 that fixes the zero dead volume valve 2.3 and the capillary sampling tube 2.1 is leveled through a fine two-dimensional surface, and the axial direction of the capillary sampling tube 2.1 is precisely aligned with the axis of the 5mm diameter and 80mm length quartz tube fixed on the customized bracket 1.4. This layout not only ensures the stability of the capillary during movement, but also ensures the accuracy of the reaction kinetics data.

[0044] In the present invention, the capillary sampling tube 2.1 can be made of any material, such as metal (common but not limited to stainless steel), quartz, glass, PEEK, etc., but because the capillary sampling tube 2.1 needs to contact and move with the material, in the actual selection, the compatibility of the material with the ambient temperature and the reaction properties, the matching of the inner diameter with the mass spectrometry sampling rate requirements, the matching of the capillary material rigidity and the movement control, and the capillary material cannot affect the reaction characteristics of the material itself (such as the metal capillary itself has catalytic properties, which may affect the catalytic reaction) and other issues should be considered. Since the capillary sampling tube 2.1 is the only component of the equipment that actually contacts the working material reaction, the sampling device can be operated under high temperature reaction conditions above 800°C by appropriately selecting the capillary material, reaching the upper limit of the chemical reaction. In the embodiment of the present invention, a preferred implementation is that the capillary sampling tube 2.1 uses a quartz capillary with high temperature resistance, reaction inertness, and excellent rigidity, with an inner diameter of 0.1mm; the reaction system adopts a methane oxidative coupling reaction with high temperature requirements (>800°C) in the chemical reaction.

[0045] In the present invention, the capillary sampling tube 2.1 and the port directly connected to the three-way structure are sealed with an O-ring of special material, and various extrusion-type sealing rings can be used to ensure sealing and meet the design requirements of the sliding of the capillary sampling tube 2.1, such as common but not limited to various polymer sealing rings, graphite sealing rings, etc. In order to ensure airtightness under different air pressures, a method of stacking and packaging multiple O-rings can be used, which is commonly used in the sealing of ship propeller shafts. In the present invention, a preferred embodiment is that the O-ring of the port directly connected to the capillary sampling tube 2.1 and the three-way structure is made of silicone material.

[0046] In the present invention, the straight-through fixed joint 2.2 serves as a relay support between the movable sealing unit 3 and the zero dead volume valve 2.3 when the length and diameter ratio of the capillary sampling tube 2.1 is large. According to the actual situation, multiple or no installation can be selected.

[0047] In the present invention, the zero dead volume valve 2.3 is a component connecting the capillary sampling tube 2.1 and the subsequent mass spectrometer device, and plays a vacuum protection role. After closing, the zero dead volume valve 2.3 is guaranteed to be in an ultra-high vacuum state that the mass spectrometer should have when it is idle. After opening, the pressure is guaranteed to be smoothly transferred to the working vacuum of the mass spectrometer, and the vacuum of the mass spectrometer working space will not be destroyed due to the accumulation of airflow at the interface of the capillary sampling tube 2.1 and the zero dead volume valve 2.3.

[0048] In the embodiment of the present invention, a preferred implementation is that all seals connected to the capillary sampling tube 2.1 are 1 / 16 "stainless steel card sets", and the inside of the pipe is zero dead volume, such as the zero dead volume valve 2.3 using a 1 / 16 "stainless steel ball valve". The seal does not affect the internal space structure of the quartz tube with a diameter of 5mm and a length of 80mm.

[0049] In the embodiment of the present invention, a preferred implementation is to use a linear slide table driven by a stepper motor as the linear drive unit 2.5, the slide table can move 60 mm, the minimum speed is 40 nm / s, and the maximum speed is 250 mm / s.

[0050] In the embodiment of the present invention, a preferred implementation is that all units are integrated on an aluminum alloy base plate to facilitate overall movement and assembly, including the reactor 1.1 and the heating and cooling module 1.2, and the total weight of the system is less than one kilogram.

[0051] In the embodiment of the present invention, a preferred implementation is to use a gas-solid catalytic system to test continuous signal acquisition.

[0052] Figure 3 This is the spatial mass spectrometry sampling result of the oxidative coupling reaction of methane (OCM). In the embodiment, the reaction tube is filled with the typical OCM catalyst Mn-Na2WO4 / SiO2, the total flow rate is 12 sccm (standard milliliters per minute), the alkoxy ratio (CH4 / O2) of the reaction gas introduced into the reaction tube is 1:1, and 8 sscm Ar is used as the internal standard carrier gas. The initial sampling point position of the capillary sampling tube is corrected to 0 mm, corresponding to the starting position of the catalyst bed, and the sampling point is moved axially to 7 mm at a speed of 3.9 μm / s at 800 ° C, from Figure 3 The gas concentration distribution with spatial resolution along the axial direction of the bed can be clearly seen. The consumption of CH4, the reaction gas, increases as the bed lengthens and the catalyst increases. The C2 product increases along the bed. The data shows the real-time change law of the conversion of reactants to products along the bed direction. Although the reaction is carried out under steady-state conditions, the device of the present invention can obtain micro-area kinetic data at different positions in real time.

[0053] The examples clearly show that the spatial capillary mass spectrometry sampling device of the present invention can obtain reaction kinetic data of catalyst micro-regions, and can still perform flexible mobile sampling operations under high temperature conditions up to 800° C., and has high practicality and reliability.

Claims

1. A spatially resolved sampling point capillary mass spectrometry sampling device, characterized in that: It includes a reaction generating unit, a capillary mass spectrometer sampling unit and a movable sealing unit, wherein: The movable sealing unit is located between the capillary mass spectrometer sampling unit and the reaction unit, and is a three-way structure having port one, port two and port three, wherein port one is directly connected to port two, port one is fixedly connected to the tail gas interface at the outlet end of the reaction unit, and port three is the tail gas discharge port, which is compatible with the normal tail gas discharge of the reaction unit; The capillary mass spectrometry sampling unit includes a capillary sampling tube, a zero dead volume valve and a driving unit. The capillary sampling tube is connected to the mass spectrometer device through the zero dead volume valve. At the same time, the capillary sampling tube passes through port 2 of the movable sealing unit and directly enters the interior of the reaction unit through the port. The N-axial space control of the capillary sampling tube is achieved by the driving unit, N≥1, so that the part of the capillary sampling tube inside the reaction unit moves relative to the reaction unit. During the movement, the sampling position of the capillary sampling tube is synchronized with the position marked by the driving unit, and the movement range of the part of the capillary sampling tube inside the reaction unit can pass through the spatial range where the material in the reaction unit is located.

2. A spatially resolved sampling point capillary mass spectrometry sampling device as claimed in claim 1, characterized in that: The reaction generating unit comprises a reactor arranged on a support platform 1, and a heating and cooling module controlled by a temperature controller is arranged on the reactor.

3. A spatially resolved sampling point capillary mass spectrometry sampling device as claimed in claim 2, characterized in that: The reactor adopts a quartz tube with a diameter of 5 mm and a length of 80 mm, and the reaction system adopts a methane oxidative coupling reaction in which the temperature requirement in the chemical reaction is >800°C.

4. A spatially resolved sampling point capillary mass spectrometry sampling device as claimed in claim 2, characterized in that: The capillary mass spectrometry sampling unit also includes a straight-through fixed joint and a second support platform. The capillary sampling tube is fixed to the second support platform via the straight-through fixed joint, and the driving unit drives the capillary mass spectrometry sampling unit to move as a whole via the second support platform.

5. A spatially resolved sampling point capillary mass spectrometry sampling device as claimed in claim 4, characterized in that: The straight-through fixed joint acts as a relay support between the movable sealing unit and the zero dead volume valve when the ratio of the length to the diameter of the capillary sampling tube is large.

6. A spatially resolved sampling point capillary mass spectrometry sampling device as claimed in claim 4, characterized in that: An O-ring is used to seal between the capillary sampling tube and port one and port two of the movable sealing unit, and the static friction between the O-ring and the capillary sampling tube is smaller than the friction of the fixed seal between the capillary sampling tube and the straight-through fixed joint and / or the zero dead volume valve.

7. A spatially resolved sampling point capillary mass spectrometry sampling device as claimed in claim 6, characterized in that: A method of stacking and packaging a plurality of the O-rings is adopted.

8. A spatially resolved sampling point capillary mass spectrometry sampling device as claimed in claim 4, characterized in that: The second support platform is leveled by a fine two-dimensional surface to precisely align the axial direction of the capillary sampling tube with the axis of the reactor fixed on the first support platform.

9. The spatially resolved sampling point capillary mass spectrometry sampling device according to claim 1, characterized in that: The reaction generating unit, the capillary mass spectrometer sampling unit and the movable sealing unit are integrated on an aluminum alloy bottom plate.

10. The spatially resolved sampling point capillary mass spectrometry sampling device according to claim 1, characterized in that: Using a gas-solid catalytic system, continuous signal acquisition was tested.

Images