A method for highly sensitive in-situ detection of reaction transient intermediates under high pressure and a detection device used therefor

Abstract

The present invention relates to a method for highly sensitive in-situ detection of reaction transient intermediates under high pressure, including sampling: obtaining intermediate products and target products in a high-pressure reaction chamber under a pressure difference to obtain a particle beam to be analyzed; photoionization: irradiating the particle beam to be analyzed with extreme ultraviolet light to cause photoionization of the particle beam to be analyzed, obtaining detectable charged ions; mass spectrometry analysis: performing mass spectrometry analysis on the charged ions obtained by photoionization, and obtaining a reaction mechanism according to the mass spectrometry analysis results; the photoionization and the mass spectrometry analysis are both carried out under the condition that the vacuum degree is ≤1×10<supgt;‑8< / supgt; Torr. An apparatus for implementing the method is also disclosed. Compared with traditional methods, the present invention can deeply understand the actual catalytic reaction mechanism and provide a scientific basis for improving the performance of catalysts. The present invention can achieve in-situ characterization of catalytic reactions under normal pressure or even a certain pressure.

Description

Technical Field

[0001] The present invention relates to a detection method and the instrument and equipment used, and particularly relates to a method for highly sensitive in-situ detection of reaction transient intermediates under high pressure and the device used. Background Art

[0002] Catalysis technology is a complex interdisciplinary science. Therefore, the progress of catalysis technology and its practical applications will depend on the parallel development of several disciplinary fields, and most likely involve the synthesis of new catalytic materials and the identification of reaction pathways of catalytic reactions. For this reason, many studies focus on developing methods that can in-situ observe catalytic reaction steps or at least investigate catalytic active sites at the atomic resolution level.

[0003] Currently, devices used to study catalytic reaction mechanisms include in-situ analyzers, such as in-situ infrared, in-situ Raman, in-situ electron microscopy and other devices. Although these means have achieved the detection of catalytic reaction transition state intermediates to a certain extent, their reaction conditions are restricted, the detection efficiency is low, and they cannot achieve high-sensitivity, efficient, continuous and real-time detection of products during the reaction. Moreover, the experimental reaction conditions are very different from the reaction conditions of actual industrial catalysis, and it is impossible to effectively detect the transition state intermediates of catalytic reactions and cannot well reflect the actual catalytic reaction mechanism. Usually, in order to better capture the transition state intermediates, technical means of electron impact ionization need to be used, but this will increase the collision between product ions, making some ions unable to exist stably, thus limiting the application of in-situ analyzers. Summary of the Invention

[0004] Aiming at the technical problems to be solved, the present invention provides a method for highly sensitive in-situ detection of reaction transient intermediates under high pressure and the device used, realizes photoionization by means of extreme ultraviolet light irradiation, comprehensively and effectively captures the transition state intermediates of catalytic reactions, and effectively and in-situ studies the reaction mechanism problems of actual catalytic systems.

[0005] To solve the above technical problems, the present invention first discloses a method for highly sensitive in-situ detection of reaction transient intermediates under high pressure, and the method includes

[0006] Sampling: Obtaining intermediate products and target products in a high-pressure reaction chamber by using pressure difference to obtain a particle beam to be analyzed, wherein the intermediate products include short-lived intermediate free radicals and intermediate transition state products, and the formed particle beam to be analyzed is a neutral particle beam;

[0007] Photoionization: The particle beam to be analyzed is irradiated with extreme ultraviolet light to cause photoionization of the particle beam to be analyzed, obtaining detectable charged ions, that is, neutral particles are ionized into charged ions through photoionization. The intermediate products generated by the reaction need to be ionized before they can be detected by the mass spectrometer. Compared with ordinary ultraviolet light (200 - 400 nm), extreme ultraviolet light has a shorter wavelength (about 100 nm), higher energy, and higher photoionization efficiency;

[0008] Mass spectrometry analysis: Perform mass spectrometry analysis on the intermediate transition state ions obtained by photoionization, and obtain the reaction mechanism based on the mass spectrometry analysis results;

[0009] Both the photoionization and mass spectrometry analysis are carried out under the condition that the vacuum degree ≤ 1×10 -8 Torr.

[0010] Furthermore, the vacuum pumping in this method uses four-stage differential pumping (i.e., multi-stage and multi-time extraction), including the first-stage differential pumping for the high-pressure reaction chamber and the second, third, and fourth-stage differential pumping for evacuating the extreme ultraviolet photoionization and mass spectrometry analysis environment.

[0011] Furthermore, the first-stage differential pumping uses a dry vacuum pump with a pumping speed of 35 m 3 / hr; the second, third, and fourth-stage differential pumping are all turbo molecular pumps, and the pumping rates are 2300 L / s, 80 L / s, and 700 L / s respectively.

[0012] The present invention also discloses a device for realizing the high-sensitivity in-situ detection method of reaction transient intermediates under high pressure as described above. The device includes a main chamber and a high-pressure reaction chamber connected to the main chamber. The upper end of the main chamber is connected to a quadrupole mass spectrometer. The lower end of the quadrupole inside the quadrupole mass spectrometer extends into the main chamber. The bottom of the quadrupole is connected to an ion channel. An ion deflector is provided at the lower end of the ion channel. One side of the ion deflector communicates with an ion lens, and an ion ionizer is provided on the other side of the ion lens. The ion ionizer communicates with the high-pressure reaction chamber through a funnel-shaped sampler. The central axes of the ion deflector, ion lens, and ion ionizer are on the same horizontal axis; the sampler communicates with the high-pressure reaction chamber through a communication port, and is also funnel-shaped, with the small-diameter spout end as the sampling end, so that the material enters along a straight line and effectively forms a uniformly distributed particle beam. The central axis of this communication port is also on the same horizontal axis as the central axes of the ion deflector, ion lens, and ion ionizer.

[0013] On the outer side of the chamber wall of the main chamber, there are two openable and closable gate valves, which are located on the front side and the left side of the main chamber respectively. The valve bodies of the two gate valves are fixed in the middle of the double-sided flange. The inner side of the double-sided flange is fixedly connected to the chamber wall of the main chamber through the gate valve connection flange. The outer side of the double-sided flange of the gate valve located on the front side of the main chamber is used to connect the extreme ultraviolet light source, and the extreme ultraviolet light can enter the main chamber through the double-sided flange and the valve body and reach the ionizer; the outer side of the double-sided flange of the gate valve located on the left side of the main chamber is connected to the collimating laser source. The collimating laser source can use a common laser source or an extreme ultraviolet light source. It is required that the beam has good focusing performance to play a good collimating role.

[0014] The main chamber is connected to a number of turbomolecular pumps, and the high-pressure reaction chamber is connected to a dry vacuum pump.

[0015] Furthermore, between the ion lens and the ionizer, there are also a number of metal sheets with central holes. The central axes of the metal sheets are on the same axis as the central axes of the ion deflector, the ion lens, the sampler and the ionizer.

[0016] Furthermore, there are three turbomolecular pumps connected to the main chamber, including a secondary turbomolecular pump connected to its bottom end, a tertiary turbomolecular pump and a quaternary turbomolecular pump located at the rear side thereof, which are respectively for second, third and fourth stage differential pumping. The dry vacuum pump is for first stage differential pumping, forming a four-stage differential pumping. The sampler and the high-pressure reaction through-hole funnel-shaped design also help to maintain a high vacuum and increase the four-stage differential pumping effect. At the same time, the four-stage differential pumping method and the above-mentioned designed structure of the device can realize the continuous real-time detection of the products during the reaction process.

[0017] The required vacuum degree of the main chamber is ≤1×10 -6 Torr, and the required vacuum degree of the mass spectrometer is ≤1×10 -8 Torr.

[0018] Furthermore, on the front side of the main chamber, there are also a main chamber viewing window flange and a number of main chamber external connection flanges; the high-pressure reaction chamber is provided with a number of reaction chamber external connection flanges; the quadrupole mass spectrometer is provided with a number of mass spectrometer external connection flanges. The viewing window flange is provided for observing the internal environment. Among them, the main chamber external connection flanges, the reaction chamber external connection flanges and the mass spectrometer external connection flanges are used as reserved interfaces. For example, the reaction chamber external connection flange can be used as a feed port, a residual gas analyzer interface, etc., which can cope with different reactions and facilitate the collection of primary reaction products. When the external connection flange is not connected to other instruments, a flange blind plate can be installed for device closure.

[0019] Further, the bottom of the main cavity is fixed on a support plate, and the lower part of the support plate is connected to a platform through three vertical telescopic mechanisms and three horizontal moving mechanisms respectively. The vertical telescopic mechanisms and the horizontal moving mechanisms are arranged at intervals, and the platform is fixed on a platform bracket.

[0020] Further, openings are provided on both the support plate and the platform on the side of the high-pressure reaction chamber, facilitating the connection pipeline of the dry pump vacuum pump to pass through.

[0021] Further, a vacuum gauge is arranged outside the quadrupole mass spectrometer. The vacuum gauge communicates with the inside of the quadrupole mass spectrometer. A quadrupole mass spectrometer bracket and a number of circuit interfaces are arranged on the top of the quadrupole mass spectrometer. The vacuum gauge is used to observe the internal vacuum degree to ensure normal detection. The setting of the quadrupole mass spectrometer bracket can not only facilitate lifting but also protect the fragile input and output circuits of the quadrupole mass spectrometer, preventing circuit damage caused by human collision. For the convenience of description, in the present invention, the side where the extreme ultraviolet light for photoionization is incident is defined as the front (this direction is used as the main view direction) as a reference to define other surfaces.

[0022] Advantages of the present invention:

[0023] 1. The present invention uses extreme ultraviolet light to perform photoionization on the collected particle beam. By combining with a high-sensitivity quadrupole mass spectrometer, it can not only achieve "soft ionization" of the intermediate transition products of the catalytic reaction, and can detect these compounds in an almost fragment-free manner, thus avoiding collisions between product ions, but also can detect the molecular structure of the transition products with high resolution. Because extreme ultraviolet light can achieve "soft ionization" for all compounds with ionization energies lower than the single-photon energy.

[0024] 2. The present invention connects the high-pressure reaction chamber with the main cavity, avoiding the loss of molecules during the transmission process. At the same time, the high-pressure reaction chamber is provided with a plurality of external flanges as different feed ports, that is, multiple catalytic reactions can be carried out synchronously.

[0025] 3. By adjusting the voltage of the quadrupole, the ions of the ion source can be focused, enabling more ions to enter the quadrupole for analysis, thereby achieving an improvement in sensitivity and being conducive to the detection of intermediate transition products.

[0026] 4. The present invention adopts the method of stepwise differential pumping, which can break the pressure barrier and material barrier between basic research and actual catalysis in the past. It is more in line with the conditions of actual industrial catalysis. At the same time, the vacuum degree of mass spectrometry detection is further improved, which is the key to ensuring the high resolution of the mass spectrometer.

[0027] In summary, compared with the traditional methods, the present invention can capture the low-concentration and short-lived transition products existing in the reaction process, enabling an in-depth understanding of the actual catalytic reaction mechanism and providing a scientific basis for improving the performance of the catalyst. The present invention can achieve in-situ characterization of catalytic reactions under normal pressure or even a certain pressure.

[0028] The present invention can not only detect the actual catalytic process, but also conduct mechanism research on the ultra-high vacuum single crystal surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a three-dimensional structural schematic diagram of the present invention;

[0030] Figure 2 is a front view structural schematic diagram of the present invention;

[0031] Figure 3 is Figure 2 a structural schematic diagram in the "A-A" direction of

[0032] Figure 4 is a left view structural schematic diagram of the present invention;

[0033] Figure 5 is Figure 4 a structural schematic diagram in the "B-B" direction of

[0034] Figure 6 is a top view structural schematic diagram of the present invention;

[0035] Figure 7 is an enlarged structural schematic diagram of the gate valve of the present invention;

[0036] Figure 8 is Figure 6 a structural schematic diagram in the "C-C" direction of

[0037] Figure 9 is Figure 8 an enlarged structural schematic diagram at position M in

[0038] Figure 10 is a rear view structural schematic diagram of the present invention;

[0039] Figure 11 is a mass spectrum obtained by detecting the application example of the present invention.

[0040] In the figure, 1 is the main chamber; 1.1 is the viewing window flange of the main chamber; 1.2 is the external connection flange of the main chamber; 2 is the high-pressure reaction chamber; 2.1 is the external connection flange of the reaction chamber; 2.2 is the flange blind plate; 2.3 is the communication port; 3 is the quadrupole mass spectrometer; 3.1 is the quadrupole mass spectrometer support; 3.2 is the quadrupole; 3.3 is the ion channel; 3.4 is the ion deflector; 3.5 is the ion lens; 3.6 is the sampler; 3.7 is the external connection flange of the mass spectrometer; 3.8 is the ion ionizer; 3.9 is the metal sheet; 4 is the secondary turbomolecular pump; 5 is the tertiary turbomolecular pump; 6 is the quaternary turbomolecular pump; 7 is the platform support; 8 is the platform; 8.1 is the horizontal moving rod; 8.2 is the vertical telescopic rod; 8.3 is the platform opening; 9 is the support plate; 9.1 is the support plate opening; 10 is the gate valve; 10.1 is the valve body; 10.2 is the outer flange; 10.3 is the inner flange; 10.4 is the gate valve connection flange; 11 is the gate valve. Detailed implementation mode

[0041] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0042] The present invention uses extreme ultraviolet light with a wavelength of about 100 nm for irradiation, so that the intermediate products of the reaction (including short-lived intermediate free radicals and intermediate transition products) and the target products are photoionized, realizing "soft ionization", and detecting these compounds in an almost fragment-free manner, that is, realizing high-sensitivity in-situ detection of reaction transient intermediates under high pressure. For this purpose, a high-sensitivity in-situ detection device for reaction transient intermediates under high pressure as shown in Figure 1-9 is designed.

[0043] For the convenience of description, in the present invention, the side where the extreme ultraviolet light for photoionization enters is regarded as the front. In the front view as shown in Figure 2 , the paper surface facing outwards is regarded as the front, the opposite side of this surface is the back, and the up, down, left and right of the paper surface respectively correspond to the up, down, left and right described.

[0044] Specifically, the device includes a main chamber 1 and a high-pressure reaction chamber 2 connected to the main chamber 1. The upper end of the main chamber 1 is connected to a quadrupole mass spectrometer 3. The lower end of the quadrupole 3.2 inside the quadrupole mass spectrometer 3 extends into the main chamber 1. The bottom of the quadrupole 3.2 is connected to an ion channel 3.3. The lower end of the ion channel 3.3 is connected to the left end of an ion lens 3.5 through an ion deflector 3.4. On the right end of the ion lens 3.5, there are three metal sheets 3.9 with central openings (the specific number and the size of the central opening are determined according to different reaction and detection requirements). An ion ionizer 3.8 is arranged on the right side of the metal sheet 3.9. The right end of the ion ionizer 3.8 is connected to the high-pressure reaction chamber 2 through a funnel-shaped sampler 3.6 (Skimmer). A funnel-shaped communication port 2.3 is opened on the left side wall of the high-pressure reaction chamber 2. This communication port 2.3 is the through hole for the sampler 3.6 to communicate with the high-pressure reaction chamber 2. The central axes of the ion deflector 3.4, the ion lens 3.5, the metal sheet 3.9, the ion ionizer 3.8, the sampler 3.6, and the communication port 2.3 are located on the same horizontal axis, with an allowable error of no more than 0.1 mm. Both the sampler 3.6 and the communication port 2.3 have a large-diameter opening facing left and a small-diameter opening facing right, that is, the small-diameter opening is the feed end and the large-diameter opening is the discharge end. The diameter of the small-diameter end of the communication port 2.3 is 2 - 8 μm, and the diameter of the small-diameter end of the sampler 3.6 is slightly smaller than that of the small-diameter end of the communication port 2.3, being 1 - 3 μm.

[0045] On the outer side of the chamber wall of the main chamber 1, there are two openable and closable gate valves 10, 11, which are respectively located on the front side and the left side of the main chamber 1. Among them, the gate valve 10 is located on the front side. Its valve body 10.1 is fixed in the middle of a double-sided flange. The double-sided flange includes an inner flange 10.3 on the inner side and an outer flange 10.2 on the outer side. The inner flange 10.3 is fixedly connected to the chamber wall of the main chamber 1 through a gate valve connection flange 10.4. The outer flange 10.2 is used to connect an extreme ultraviolet light source. In order to ensure a high-vacuum environment, a small chamber (not marked in the figure) is also connected between the extreme ultraviolet light source and the outer flange 10.2. The extreme ultraviolet light can enter the main chamber 1 in sequence through the small chamber, the outer flange 10.2, the valve body 10.1, the inner flange 10.3, and the gate valve connection flange 10.4, and reach the main chamber 1 through the through hole on the side wall of the ion ionizer 3.8, as Figure 5 shown by the dotted line L with an arrow in

[0046] The gate valve 11 is located on the left side of the main chamber 1. Its structure is the same as that of the gate valve 10 and is connected to a laser source for collimation. After the beam of this laser source enters the main chamber 1, it passes through the ion deflector 3.4, the ion lens 3.5, the metal sheet 3.9, the ion ionizer 3.8, the sampler 3.6, and the communication port 2.3 in sequence, as Figure 5 shown by the dotted line T with an arrow in

[0047] For the convenience of observation and external connection of instruments and equipment, a main chamber viewing window flange 1.1 and several main chamber external connection flanges 1.2 are also provided on the front side of the main chamber 1; several reaction chamber external connection flanges 2.1 are provided on the high-pressure reaction chamber 2. When the external connection of each flange is not required, a flange blind plate is used for sealing (such as the flange blind plate 2.2 provided on the high-pressure reaction chamber 2). The reactive external connection flange 2.1 can be used for external connection of different reactions to facilitate the collection of primary reaction products, and can also be connected to a residual gas analyzer (RGA) for analysis of the reaction gas composition and inspection of the airtightness of the device, etc. All external connection flanges can be set to different sizes according to needs, such as 2.75 inches, 3.75 inches, 6 inches, 8 inches, etc.

[0048] Since photoionization and mass spectrometry analysis require a high-vacuum environment, the present invention adopts a four-stage differential pumping system to improve the detection sensitivity and resolution of the device, including a dry vacuum pump connected to the high-pressure reaction chamber 2 through the reaction chamber external connection flange 2.1 as the first-stage pumping difference, with a pumping speed of 35m 3 / hr, so that the pressure of the high-pressure reaction chamber 2 where the reaction has not been started originally reaches the requirement of the fore-vacuum. The main chamber 1 is connected with three turbomolecular pumps, namely a secondary turbomolecular pump 4 connected to its bottom end, a tertiary turbomolecular pump 5 located at its rear side, and a quaternary turbomolecular pump 6, which are used as the second, third, and fourth-stage pumping differences respectively, and the pumping rates are 2300L / s, 80L / s, and 700L / s respectively.

[0049] The bottom of the main cavity 1 is fixed on the support plate 9. The support plate 9 is respectively connected to the platform 8 through three vertical telescopic mechanisms and three horizontal moving mechanisms below. The vertical telescopic mechanisms and the horizontal moving mechanisms are arranged at intervals. The platform 8 is fixed on the platform bracket 7. The secondary turbomolecular pump 4 passes through the support plate 9 downward and enters the platform 8 and then into the interior of the platform bracket 7. The platform bracket 7 is a frame composed of longitudinal and transverse fixed rods and is vertically penetrated. Openings are provided on the support plate 9 and the platform 8 on one side of the high-pressure reaction chamber 2, namely a support plate opening 9.1 and a platform opening 8.3, to facilitate the passage of the pipeline of the externally connected dry vacuum pump.

[0050] A support plate opening 9.1 and a platform opening 8.3 are respectively provided on the support plate 9 and the platform 8 on one side of the high-pressure reaction chamber 2. The horizontal moving mechanism and the vertical telescopic mechanism adopt common fixed structures. The horizontal moving mechanism includes a horizontal moving rod 8.1 and adjusting mechanisms and fixing components provided at both ends of the horizontal moving rod 8.1; the vertical telescopic mechanism includes a vertical telescopic rod 8.2 and adjusting mechanisms and fixing components provided at both ends of the vertical telescopic rod 8.2. When the device is unbalanced, adjust the adjusting mechanism, and after leveling, fix the position of the adjusting mechanism.

[0051] On the outside of the quadrupole mass spectrometer 3, a vacuum gauge (not shown in the figure) is connected through a mass spectrometer external flange 3.7. The vacuum gauge communicates with the inside of the quadrupole mass spectrometer 3. On the top of the quadrupole mass spectrometer 3, there are a quadrupole mass spectrometer support 3.1 and a number of circuit interfaces.

[0052] Before using this device to in-situ detect high-pressure reaction transient intermediates, first adjust the positions of the ion deflector 3.4, ion lens 3.5, metal sheet 3.9, ion ionizer 3.8, sampler 3.6 and connection port 2.3 to ensure collimation. Then turn on the dry vacuum pump to evacuate the high-pressure reaction chamber 2 so that its pressure dynamically reaches 1×10 -2 Torr to prevent the automatic gas diffusion in the high-pressure reaction chamber 2 from affecting the detection results. Gradually turn on the secondary turbomolecular pump 4, tertiary turbomolecular pump 5 and quaternary turbomolecular pump 6 to evacuate the main chamber 1 and the quadrupole mass spectrometer 3 so that the vacuum degree in the main chamber 1 is ≤1×10 -6 Torr and the vacuum degree in the ion electrical appliance 3.8 is ≤1×10 -8 Torr. Then connect the extreme ultraviolet light source and open the valve body 10.1 of the gate valve 10. Since the high-pressure reaction chamber 2 and the main chamber 1 use different vacuum pumping equipment and different vacuum pumping levels, the pressure in the high-pressure reaction chamber 2 is much higher than that in the main chamber 1. The intermediate products and target products in the high-pressure reaction chamber 2 enter from the small-diameter end of the funnel-shaped connection port 2.3 under the pressure difference, diffuse, and then enter from the small-diameter end of the funnel-shaped sampler 3.6 to form a uniformly distributed straight particle beam. Then it further reaches the ion ionizer 3.8, where photoionization is achieved under the irradiation of extreme ultraviolet light to form intermediate transition state ions. The intermediate transition state ions pass through the small hole with a diameter not greater than the minimum diameter inside the ion lens 3.5 on the ion ionizer 3.8, and further pass through the metal sheet 3.9 and the ion lens 3.5 in sequence, and then are focused and accelerated. After being screened by the ion deflector 3.4 (such as according to the set mass-to-charge ratio parameter), useful ions are captured, and then reach the quadrupole 3.2 through the ion channel 3.3 for further screening (such as according to the set mass ratio parameter), and then the ion signal is collected. After software analysis, a mass spectrometry analysis chart is obtained. Combining with other characterization means, different reaction mechanisms are verified.

[0053] Specific application examples:

[0054] Supported noble metal catalysts have been widely used in various heterogeneous catalytic reactions. During the induction period of gas-phase methanol carbonylation reaction, dispersion can be carried out through bromohydrocarbon or iodohydrocarbon. The nanoparticles of most noble metals (such as Ru, Rh, Pd, Ag) supported on activated carbon (AC) are completely atomically dispersed in the form of mononuclear complexes by reacting with the mixture of CH 3 I and CO. This example takes the dispersion process of Rh nanoparticles as an example for illustration. CH 3The cracking reaction of I may occur on the metal surface, generating a large number of free radicals. If the quenching of short-lived free radicals can be inhibited under ultra-low pressure or by high dilution of the feed gas, the signals of methyl radicals (CH 3 ·) and iodine radicals (I·) can be detected. When CO / CH 3 I passes through Rh / AC, transient free radicals can be observed in the device of the present invention.

[0055] After introducing CO / CH 3 I into the high-pressure reaction chamber 2, according to the catalytic reaction conditions, the pressures of the high-pressure reaction chamber 2 and the main chamber 1 are maintained at 1×10 -2 Torr and 1×10 -7 Torr. At room temperature, CO is used as the carrier gas to carry CH 3 I vapor into the high-pressure reaction chamber 2. Then, after the CO / CH 3 I mixture in the high-pressure reaction chamber 2 undergoes a catalytic reaction, the substance to be detected is introduced into the quadrupole mass spectrometer by means of differential pressure. The substance entering the ion ionizer 3.8 is ionized by extreme ultraviolet light with a wavelength of 118 nm. By detecting with the quadrupole mass spectrometer 3, a mass spectrum as shown in Figure 11 can be obtained, thereby detecting different reactants and free radicals. The detection of these free radicals indicates that the combined action of CO, CH 3 I and O-AC is essential for the atomic dispersion of Rh.

[0056] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for highly sensitive in-situ detection of reaction transient intermediates under high pressure, characterized in that: This method includes Sampling: Obtaining intermediate products and target products in the high-pressure reaction chamber by using the pressure difference between the high-pressure reaction chamber and the main chamber to obtain a particle beam to be analyzed; Photoionization: Irradiating the particle beam to be analyzed with extreme ultraviolet light to cause photoionization of the particle beam to be analyzed to obtain detectable charged ions; Mass spectrometry analysis: Performing mass spectrometry analysis on the detectable charged ions obtained by photoionization, and obtaining the reaction mechanism according to the mass spectrometry analysis results; The dynamic pressure value in the high-pressure reaction chamber is 1×10 -2 Torr, and the vacuum degree in the main chamber is ≤ 1×10 -6 Torr; The photoionization and mass spectrometry analysis are both carried out under the condition that the vacuum degree ≤ 1×10 -8 Torr; In this method, vacuum pumping is carried out by four-stage differential pumping, including the first-stage differential pumping for pumping the high-pressure reaction chamber and the second, third, and fourth-stage differential pumping for pumping the extreme ultraviolet photoionization, mass spectrometry analysis environment, and the main chamber.

2. The method for highly sensitive in-situ detection of reaction transient intermediates under high pressure according to claim 1, characterized in that: The first-stage differential pumping uses a dry vacuum pump with a pumping speed of 35 m 3 / hr; the second, third, and fourth-stage differential pumping are all turbomolecular pumps with pumping speeds of 2300 L / s, 80 L / s, and 700 L / s respectively.

3. An apparatus for implementing the method for highly sensitive in-situ detection of reaction transient intermediates under high pressure according to any one of claims 1-2, characterized in that: This apparatus includes a main chamber (1) and a high-pressure reaction chamber (2) connected to the main chamber (1). The upper end of the main chamber (1) is connected to a quadrupole mass spectrometer (3). The lower end of the quadrupole (3.2) inside the quadrupole mass spectrometer (3) extends into the main chamber (1). The bottom of the quadrupole (3.2) is connected to an ion channel (3.3). An ion deflector (3.4) is provided at the lower end of the ion channel (3.3). One side of the ion deflector (3.4) communicates with an ion lens (3.5). An ion ionizer (3.8) is provided on the other side of the ion lens (3.5). The ion ionizer (3.8) communicates with the high-pressure reaction chamber (2) through a funnel-shaped sampler (3.6). The central axes of the ion deflector (3.4), the ion lens (3.5), the sampler (3.6), and the ion ionizer (3.8) are located on the same horizontal axis; Two openable and closable gate valves (10, 11) are provided on the outer side of the chamber wall of the main chamber (1), respectively located on the front side and the left side of the main chamber (1). The valve bodies of the two gate valves are fixed in the middle of a double-sided flange. The inner side of the double-sided flange is fixedly connected to the chamber wall of the main chamber (1) through a gate valve connecting flange (10.4). The outer side of the double-sided flange of the gate valve (10) located on the front side of the main chamber (1) is used to connect an extreme ultraviolet light source. The extreme ultraviolet light can enter the main chamber (1) through the double-sided flange and the valve body (10.1) and reach the ion ionizer (3.8); The outer side of the double-sided flange of the gate valve (11) located on the left side of the main chamber (1) is connected to a collimating laser source; The main chamber (1) is connected with a plurality of turbomolecular pumps, and the high-pressure reaction chamber (2) is connected with a dry vacuum pump.

4. The apparatus for implementing the method for highly sensitive in-situ detection of reaction transient intermediates under high pressure according to claim 3, characterized in that: Between the ion lens (3.5) and the ion ionizer (3.8), a plurality of metal sheets (3.9) with central openings are further provided. The central axes of the metal sheets (3.9) are located on the same axis as the central axes of the ion deflector (3.4), the ion lens (3.5), the sampler (3.6), and the ion ionizer (3.8).

5. The device for realizing the method for highly sensitive in-situ detection of reaction transient intermediates under high pressure according to claim 3, characterized in that: There are three turbomolecular pumps connected to the main chamber (1), including a two-stage turbomolecular pump (4) connected to its bottom end, a three-stage turbomolecular pump (5) located at its rear side, and a four-stage turbomolecular pump (6).

6. The device for realizing the method for highly sensitive in-situ detection of reaction transient intermediates under high pressure according to claim 3, characterized in that: A main chamber viewing window flange (1.1) and a plurality of main chamber external connection flanges (1.2) are further provided on the front side of the main chamber (1); a plurality of reaction chamber external connection flanges (2.1) are provided on the high-pressure reaction chamber (2); and a plurality of mass spectrometer external connection flanges (3.7) are provided on the quadrupole mass spectrometer (3).

7. The device for realizing the method for highly sensitive in-situ detection of reaction transient intermediates under high pressure according to claim 3, characterized in that: The bottom of the main chamber (1) is fixed on a support plate (9). Below the support plate (9), it is respectively connected to a platform (8) through three vertical telescopic mechanisms and three horizontal moving mechanisms. The vertical telescopic mechanisms and the horizontal moving mechanisms are arranged at intervals, and the platform (8) is fixed on a platform bracket (7).

8. The device for realizing the method for highly sensitive in-situ detection of reaction transient intermediates under high pressure according to claim 7, characterized in that: Openings are provided on both the support plate (9) and the platform (8) on one side of the high-pressure reaction chamber (2).

9. The device for realizing the method for highly sensitive in-situ detection of reaction transient intermediates under high pressure according to claim 3, characterized in that: A vacuum gauge is provided on the outside of the quadrupole mass spectrometer (3). The vacuum gauge communicates with the inside of the quadrupole mass spectrometer (3). A quadrupole mass spectrometer support (3.1) and a plurality of line interfaces are provided on the top of the quadrupole mass spectrometer (3).

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