An in-situ diffuse reflectance infrared spectroscopy device for generating and strengthening catalyst surface discharge

Abstract

The invention discloses an in-situ diffuse reflection infrared spectroscopy device for generating and strengthening catalyst surface discharge, which relates to the field of infrared spectroscopy analysis and testing systems, and comprises a lower shell and an upper end cover; the lower shell and the upper end cover form a closed space; the upper end cover is provided with an infrared light incident window and an infrared light exit window, and the infrared incident and exit units are incident and exit through the infrared light incident window and the infrared light exit window; a high temperature resistant insulator is arranged in the lower shell; the high temperature insulator is a hollow structure, a bracket is arranged in the hollow structure, a high temperature resistant insulating layer is arranged at the upper end of the bracket, a high voltage electrode and a grounding electrode are arranged on the high temperature resistant insulating layer, a medium is arranged between the high voltage electrode and the grounding electrode, and a spherical medium and a catalyst are arranged between the medium. The device can detect the in-situ diffuse reflection of plasma-catalytic surface reaction in real time.

Description

Technical Field

[0001] The invention relates to an infrared spectrum analysis and testing system, in particular to an in-situ diffuse reflection infrared spectrum device for generating and strengthening catalyst surface discharge. Background Art

[0002] Low-temperature plasma-catalytic technology is a very promising method for degrading volatile organic pollutants, but due to the complexity of the reaction process, its reaction mechanism and the interaction mechanism between reactants have not yet been clarified. In addition to general gas-solid phase reactions, the reaction process also involves reactions involving electrons, ions, free radicals and metastable molecules. These reactions are very rapid, which brings difficulties to research. At present, the research on the low-temperature plasma-catalytic reaction process is mainly carried out by analyzing the composition of gas-phase products and characterizing the catalyst after the reaction, and the intermediate reaction process is guessed by analyzing the indirect detection results. Even though some researchers use emission spectroscopy and laser-induced fluorescence methods to in situ detect the reaction between plasma and gas-phase reactants during the reaction process, these methods cannot detect surface catalytic reactions involving plasma. However, the surface catalytic reaction involving plasma is very different from the gas-phase reaction, which is also the key to low-temperature plasma-catalytic technology. Therefore, it is very necessary to provide a device and method that can detect the surface catalytic reaction process involving plasma in situ.

[0003] In summary, at present there is no relevant device that can provide in-situ detection of catalyst surface species structure in a plasma environment. Summary of the invention

[0004] The present invention provides an in-situ diffuse reflection infrared spectroscopy device for generating and strengthening catalyst surface discharge, and the present invention is achieved through the following technical solutions:

[0005] An in-situ diffuse reflection infrared spectroscopy device for generating and strengthening catalyst surface discharge comprises a lower shell and an upper end cover; the lower shell and the upper end cover form a closed space; the upper end cover is provided with an infrared light incident window and an infrared light exit window, and infrared incident and exit units are incident and emitted through the infrared light incident window and the infrared light exit window; a high-temperature resistant insulator is arranged in the lower shell; the high-temperature insulator is a hollow structure, a bracket is arranged in the hollow structure, a high-temperature resistant insulating layer is arranged on the upper end of the bracket, a high-voltage electrode and a grounding electrode are arranged on the high-temperature resistant insulating layer, a medium is arranged between the high-voltage electrode and the grounding electrode, and a catalyst is arranged between the medium.

[0006] Furthermore, an electric heating layer is provided inside the high temperature resistant insulator for heating the catalyst.

[0007] Furthermore, spherical media are arranged between the media, and catalysts are placed on the spherical media.

[0008] Furthermore, a cooling water pipeline is arranged outside the high temperature resistant insulator.

[0009] Furthermore, the high-voltage electrode is connected to a high-voltage electrode lead; and the grounding electrode is connected to a grounding electrode lead.

[0010] Furthermore, a thermocouple is installed in the high temperature resistant insulating layer.

[0011] Furthermore, a gas outlet is provided on the lower shell body; and a gas inlet is provided on the upper end cover.

[0012] Furthermore, a cooling water inlet and a cooling water outlet are provided on the cooling water pipeline.

[0013] Furthermore, an observation window is provided on the upper end cover; and a pressure gauge is provided at the gas inlet.

[0014] Furthermore, the medium is alumina or quartz glass, and the spherical medium is alumina ball, glass ball, quartz ball, or ferroelectric.

[0015] Inside the spectral device is a reaction device, the main body of which is a high-temperature resistant insulator inlaid and connected with a metal shell. The interior is hollow and has a bracket. Above the bracket is a high-temperature resistant insulating layer, which is a certain distance away from the top plane of the insulator for placing spherical media and catalysts. The two sides of the inner surface of the insulator are the media required for discharge. The top of the media is flush with the top plane of the insulator, and the lower part is embedded in the insulating layer to fix the position. Electrodes are placed between the media and the inner surface of the insulator. The media and electrodes cooperate to perform dielectric barrier discharge and create the conditions required for the experiment. The spherical media in the discharge area can promote surface discharge, so that the generated surface streamer propagates to the catalyst surface.

[0016] The insulator is embedded with a ring-shaped electric heating layer, which is used to pre-treat certain catalysts: that is, heating in an inert gas atmosphere for several hours to remove moisture and carbon dioxide gas in the catalyst, and at the same time, the catalyst can be activated to a certain extent. Thermocouples are embedded in the insulation layer for real-time detection of temperature during the heating process. The insulator is surrounded by cooling pipes to quickly cool down and heat the pre-treated catalyst, reducing the waiting time for the experiment.

[0017] The outside of the spectrometer is a sealed metal shell, which is divided into two parts, the upper part is equipped with two infrared windows, an observation window and a gas channel; the lower part is equipped with a cable channel, a cooling water inlet, a cooling water outlet and a gas channel. The upper and lower parts of the shell are connected by screws around the shell.

[0018] The two infrared windows on the upper part are located opposite to each other to allow the IR beam to pass through and reflect for in-situ infrared spectrum detection. The glass window on the side is used to observe the discharge during the experiment and grasp the specific conditions of the experiment. The gas channel on the top provides inert gas to ensure the gas environment in the spectral device, and a barometer is also provided on the side of the channel.

[0019] The cable channels in the lower part of the shell are located on two different sides. The cables in the channels are connected to the high-voltage plate and the ground respectively, and the cables are in the insulating sleeve. The cooling water inlet and outlet are located on both sides of the grounding cable respectively. The cooling water pipeline carries the heat of the internal reaction process through this inlet and outlet for heat exchange. The lower gas channel opening is located below the high-voltage cable, and the air in the spectral device is discharged from here.

[0020] Compared with the existing device, the advantages of the present invention are:

[0021] 1. Low-temperature plasma is generated in the form of double dielectric barrier discharge. The dielectric and the side insulators isolate the catalyst from the electrode, avoiding the interference of high voltage gradient and surface charge on the electrode surface, and at the same time being able to generate stable surface plasma.

[0022] 2. Placing all catalysts in the discharge area and adding spherical media in the discharge area reduces the discharge voltage, promotes surface discharge, and allows the discharge current to propagate to the upper surface of the catalyst layer, generating a plasma-catalytic surface reaction phenomenon on the upper surface.

[0023] 3. The heating layer is placed on one side and side of the grounding electrode, avoiding the area near the high-voltage electrode, ensuring safety while providing a certain temperature for the discharge area.

[0024] 4. It realizes an integrated solution for catalyst heating pretreatment, dielectric barrier discharge, and in-situ diffuse reflectance infrared spectroscopy detection process, which simplifies the complexity of the experimental personnel's operation in the detection experiment.

[0025] 5. It can be applied to detection under various experimental conditions, including but not limited to experimental scenarios with heating and without heating, discharge to generate plasma and without discharge and their combination conditions.

[0026] 6. Additional observation windows and barometers are provided to facilitate researchers to observe the discharge conditions and the air pressure conditions in the spectral device in real time, and to understand and control the progress of the experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a front schematic diagram of the present invention.

[0028] Figure 2 It is a top view of the present invention.

[0029] Figure 3 It is a cross-sectional view of the internal reaction device from above.

[0030] The reference numerals are as follows:

[0031] 1-lower shell, 2-upper end cover, 3-infrared light incident window, 4-infrared light exit window, 5-observation window, 6-gas inlet, 7-pressure gauge, 8-gas outlet, 9-insulating layer, 10-insulating sleeve, 11-high voltage electrode lead, 12-high temperature resistant insulator, 13-high voltage electrode, 14-grounding electrode, 15-medium, 16-grounding electrode lead, 17-high temperature resistant insulating layer, 18-bracket, 19-catalyst, 20-spherical medium, 21-electric heating layer, 22-thermocouple, 23-cooling water pipeline, 24-cooling water inlet, 25-cooling water outlet, 26-sealed threaded hole. DETAILED DESCRIPTION

[0032] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0033] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "axial", "radial", "vertical", "horizontal", "inner", "outer" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0034] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] The following first describes in detail the embodiments of the present invention with reference to the accompanying drawings.

[0036] Reference Figure 1 , Figure 2 The upper end cover 2 of the device is provided with an infrared incident window 3 and an infrared exit window 4 on opposite sides, and a glass observation window 5 is provided next to it. The top of the upper end cover 2 of the device is provided with a gas inlet 6 and a pressure gauge 7 on the side. The front of the lower shell 1 of the device is provided with a grounding electrode lead 16 in the middle, cooling water inlets 24 and cooling water outlets 25 on both sides. There are 4 sealing threaded holes around the device, and the device shell is sealed and connected by screws.

[0037] Reference Figure 1 , Figure 3 The side of the lower shell 1 of the device is provided with a gas outlet 8 and a high-voltage electrode lead 11 located above it, and the insulating layer 9 and the insulating sleeve 10 provide insulation protection between the shell and the electrode lead. The main body of the internal reaction device, the high-temperature resistant insulator 12, is hollow inside, and a bracket 18 is placed inside it. The high-temperature resistant insulating layer 17 above the bracket 18 cooperates with the high-temperature resistant insulator 12 to fix the medium 15 on both sides of the inner surface of the insulator. High-voltage electrodes 13 and grounding electrodes 14 are placed between the medium 15 on both sides and the inner surface of the insulator respectively. An annular electric heating layer 21 is embedded in the insulator to heat the catalyst 19 on the insulating layer; the thermocouple 22 in the insulating layer provides temperature measurement; the insulator is surrounded by a cooling water pipe 23.

[0038] The catalyst 19 and the spherical medium 20 are placed in a space consisting of the plate-like medium, the insulators on the side and the insulating layer at the bottom.

[0039] The working process of the in-situ diffuse reflection infrared spectroscopy device for generating and strengthening catalyst surface discharge of the present invention is described below:

[0040] First, pre-treat the catalyst: open the upper end cover 2, place the spherical medium 20 and the catalyst 19 on the high temperature resistant insulating layer 17, install the upper end cover 2, and seal it with threads. Inert gas is introduced from the top of the upper end cover 2, and the lower shell 1 discharges the air in the device. Power on the electric heating layer 21 to heat the catalyst. After the treatment is completed, turn off the power and turn on the cooling water circulation switch to cool the catalyst 19. Read the temperature in the reaction device with the thermocouple 22, and turn off the cooling water circulation after cooling to a suitable temperature. In special cases, pre-treatment can be performed by vacuuming.

[0041] After pretreatment, infrared light is injected from the infrared light incident window 3, and the infrared light irradiates the catalyst surface in the reaction device and then is reflected and emitted from the infrared light exit window 4. The external device receives the infrared light and performs infrared spectrum detection. At this time, the inert gas can be switched to a gas containing reactants or probe molecules and maintained in a continuous flow state.

[0042] The ground electrode 14 is grounded, and the high-voltage electrode 13 is connected to high voltage electricity, so that dielectric barrier discharge occurs and low-temperature plasma is generated in the area where the catalyst is located.

[0043] Observe the discharge condition from the observation window 5, and perform spectrum detection after it becomes stable.

[0044] During the detection process, detection can be performed under different conditions and at different times according to needs to obtain the required spectrum.

[0045] Based on the working mechanism of this device, the infrared detection results at any time during the plasma-catalytic reaction can be obtained, and the real-time in-situ diffuse reflectance infrared spectrum of the plasma-catalytic surface reaction can be obtained. By tracking and characterizing the catalyst surface reaction and analyzing the changes in molecular structure information in the infrared spectrum, the information of the reaction intermediates and products can be easily obtained, providing favorable conditions for the analysis of the reaction mechanism.

[0046] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0047] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. An in-situ diffuse reflectance infrared spectroscopy device for generating and strengthening catalyst surface discharge, characterized in that: The gas inlet (6) is provided on the upper end cover (2); the lower shell (1) and the upper end cover (2) form a closed space; the lower shell (1) is provided with a gas outlet (8); and the upper end cover (2) is provided with a gas inlet (6); The upper end cover (2) is provided with an infrared light incident window (3) and an infrared light exit window (4), and the infrared light incident and exit units are incident and emitted through the infrared light incident window (3) and the infrared light exit window (4); A high temperature resistant insulator (12) is arranged in the lower shell (1); an electric heating layer (21) is also arranged in the high temperature resistant insulator (12) for heating the catalyst (19); the high temperature resistant insulator (12) is a hollow structure, a bracket (18) is arranged in the hollow structure, a high temperature resistant insulating layer (17) is arranged on the upper end of the bracket (18), a high voltage electrode (13) and a grounding electrode (14) are arranged on the high temperature resistant insulating layer (17), a medium (15) is arranged between the high voltage electrode (13) and the grounding electrode (14), and a catalyst (19) is arranged between the medium (15); a spherical medium (20) is also arranged between the medium (15), and a catalyst (19) is arranged on the spherical medium (20), and the medium (15), the spherical medium (20), the high voltage electrode (13) and the grounding electrode (14) cooperate to perform dielectric barrier discharge.

2. The in-situ diffuse reflectance infrared spectroscopy device for generating and strengthening catalyst surface discharge according to claim 1, characterized in that: A cooling water pipeline (23) is arranged outside the high temperature resistant insulator (12).

3. The in-situ diffuse reflectance infrared spectroscopy device for generating and strengthening catalyst surface discharge according to claim 1, characterized in that: The high-voltage electrode (13) is connected to a high-voltage electrode lead wire (11); and the grounding electrode (14) is connected to a grounding electrode lead wire (16).

4. The in-situ diffuse reflectance infrared spectroscopy device for generating and strengthening catalyst surface discharge according to claim 1, characterized in that: A thermocouple (22) is installed in the high temperature resistant insulating layer (17).

5. The in-situ diffuse reflectance infrared spectroscopy device for generating and strengthening catalyst surface discharge according to claim 2, characterized in that: The cooling water pipeline (23) is provided with a cooling water inlet (24) and a cooling water outlet (25).

6. The in-situ diffuse reflectance infrared spectroscopy device for generating and strengthening catalyst surface discharge according to claim 1, characterized in that: The upper end cover (2) is also provided with an observation window (5); and a pressure gauge (7) is provided at the gas inlet (6).

7. The in-situ diffuse reflectance infrared spectroscopy device for generating and strengthening catalyst surface discharge according to claim 1, characterized in that: The medium (15) is aluminum oxide or quartz glass, and the spherical medium (20) is an aluminum oxide ball, a glass ball, a quartz ball, or a ferroelectric.

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