An in-situ infrared device based on modulated excitation spectroscopy
By designing an in-situ infrared device based on modulated excitation spectrum, using a mixing unit and electromagnetic valve to control solution mixing, and combining a liquid pump and overflow unit, a simplified structure and low-cost catalytic reaction detection were achieved, solving the problems of complexity and high cost of existing devices, and realizing efficient detection of intermediate species in catalytic reactions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2020-12-10
- Publication Date
- 2026-03-20
AI Technical Summary
Existing in-situ infrared devices are complex in structure and have high operating costs.
An in-situ infrared device based on modulated excitation spectrum was designed, including a mixing unit and an in-situ infrared cell. The mixing of two solutions is controlled by an electromagnetic valve control system to form periodic concentration changes, and a liquid pump and an overflow unit are used to ensure that the solution flows uniformly over the surface of the solid catalyst, simplifying the structure and reducing costs.
It enables modulation excitation spectrum detection on a total reflection infrared device. It has a simple structure, low operating cost, can accurately detect intermediate species in catalytic reactions, and ensures that the solution flows uniformly across the catalyst surface.
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Figure CN114624206B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to a modulation excitation spectrum based in-situ infrared device, and belongs to the technical field of instruments and equipment. BACKGROUND
[0002] Modulation excitation spectrum is a kind of surface characterization technology developed in recent years, which can be combined with various in-situ characterization technologies. Modulation excitation spectrum mainly observes the changes of signals obtained by in-situ characterization technology by periodically changing the parameters related to the reaction, such as pressure, concentration, Ph, etc., so as to analyze the mechanism of catalytic reaction. This technology can be combined with various in-situ characterization technologies, such as total reflection in-situ infrared technology.
[0003] The total reflection infrared technology (ATR-IR) developed in recent years is an effective in-situ characterization technology for detecting solid-liquid interface, which can detect infrared absorption spectrum through internal reflection of crystal. When the incident angle is greater than the critical angle, total reflection occurs, a part of light penetrates the crystal surface to a certain depth and is absorbed by the sample at a specific frequency, and finally forms an infrared spectrum. The combination of ATR-IR and modulation excitation spectrum can accurately identify the intermediate species of catalytic reaction. However, the existing in-situ infrared device has complex structure and high use cost. SUMMARY
[0004] The present application provides a modulation excitation spectrum based in-situ infrared device, which can solve the problem of complex structure and high use cost of the existing in-situ infrared device.
[0005] The present application provides a modulation excitation spectrum based in-situ infrared device, which comprises: a mixed solution unit for mixing a first solution and a second solution, and regulating the mixing ratio of the first solution and the second solution to make the concentration of the mixed solution change periodically; an in-situ infrared cell comprising a cylindrical cell body with an open bottom end and an infrared crystal for closing the open bottom end of the cylindrical cell body, and a solid catalyst located in the cylindrical cell body and fixed on the infrared crystal; an infrared light beam can be totally reflected in the infrared crystal; the side wall of the cylindrical cell body is provided with a liquid inlet and a liquid outlet; the mixed solution flows into the cylindrical cell body from the liquid inlet and flows out from the liquid outlet after in-situ reaction with the solid catalyst.
[0006] Optionally, the device further comprises a liquid pump arranged between the mixed solution unit and the in-situ infrared cell; the liquid pump is used to deliver the mixed solution mixed by the mixed solution unit into the in-situ infrared cell.
[0007] Optionally, the mixing unit comprises a first container, a first output pipeline connected to the first container, a second container, a second output pipeline connected to the second container, and a mixing pipeline in communication with the output ends of the first output pipeline and the second output pipeline; the output end of the mixing pipeline is in communication with the input end of the liquid pump; the first container contains a first solution; the second container contains a second solution; the first output pipeline is provided with a first valve for controlling the output flow rate of the first solution; the second output pipeline is provided with a second valve for controlling the output flow rate of the second solution.
[0008] Optionally, the device further comprises an overflow unit, the input end of the overflow unit is connected to the output end of the liquid pump; the output end of the overflow unit is connected to the liquid inlet of the in-situ infrared cell; the output end of the overflow unit is flat, and the shape of the output end of the overflow unit is adapted to the shape of the liquid inlet of the in-situ infrared cell.
[0009] Optionally, the width of the output end of the overflow unit is equal to the width of the infrared crystal.
[0010] Optionally, the overflow unit comprises a containing box and an overflow pipeline; the first end of the overflow pipeline is inserted into the containing box from the bottom end of the containing box, and the second end of the overflow pipeline is connected to the liquid inlet of the in-situ infrared cell; the sidewall of the containing box is provided with a liquid inlet, and the liquid inlet is connected to the output end of the liquid pump.
[0011] Optionally, the infrared crystal is any one of zinc selenide, silicon, diamond and germanium.
[0012] Optionally, the working temperature of the in-situ infrared cell is -20℃ to 500℃.
[0013] Optionally, the concentration variation waveform of the mixed solution is any one of a sine wave, a cosine wave, a square wave and a triangular wave.
[0014] Optionally, the first valve and / or the second valve is an electromagnetic valve.
[0015] The beneficial effects that can be produced by the present application include:
[0016] (1) The in-situ infrared device based on the modulation excitation profile provided by the application mainly consists of a mixed solution unit and an in-situ infrared cell. The mixed solution unit in the device mainly controls the mixing of two solutions through an electromagnetic valve control system, forms a stream with a certain concentration change within a certain time, thereby forming a periodic signal, detects the signal of the surface of the solid catalyst in the in-situ infrared cell through an infrared spectrum detection device, and obtains the modulation excitation profile. The device can realize the modulation excitation profile on the total reflection infrared device, has a simple structure, and has a low use cost.
[0017] (2) The in-situ infrared device based on the modulation excitation profile provided by the application sets an overflow unit between the liquid pump and the in-situ infrared cell. Since the outlet of the overflow unit is flat and has the same width as the infrared crystal, the liquid with different concentrations can uniformly flow through the surface of the solid catalyst. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1 The structure schematic diagram of the in-situ infrared device based on the modulation excitation profile provided by the embodiment of the application is shown in the figure.
[0019] Figure 2 The structure schematic diagram of the overflow unit provided by the embodiment of the application is shown in the figure.
[0020] Figure 3 The infrared spectrum diagram of cyclohexanol measured by the embodiment of the application is shown in the figure.
[0021] Figure 4 The modulation excitation profile diagram for square wave adjustment of the spectrum signal at 2980 cm-1 provided by the embodiment of the application is shown in the figure.
[0022] Component and figure mark list:
[0023] 11, first container; 12, second container; 13, first valve; 14, second valve; 15, liquid pump; 16, overflow unit; 161, containing box; 162, overflow pipe; 17, cylindrical cell body; 18, infrared crystal; 19, solid catalyst; 20, infrared light beam; 21, sealing ring. DETAILED DESCRIPTION
[0024] The application will be described in detail below in combination with the embodiments, but the application is not limited to these embodiments.
[0025] The embodiment of the application provides an in-situ infrared device based on a modulation excitation profile, as shown in the figure. Figure 1As shown, the device comprises: a mixed solution unit for mixing the first solution and the second solution and regulating the mixing ratio of the first solution and the second solution so that the concentration of the mixed solution is periodically changed; an in-situ infrared cell comprising a cylindrical cell body 17 with an open bottom end and an infrared crystal 18 for closing the open bottom end of the cylindrical cell body 17, and a solid catalyst 19 located in the cylindrical cell body 17 and fixed on the infrared crystal 18; an infrared light beam 20 can be totally reflected in the infrared crystal 18; the side wall of the cylindrical cell body 17 is provided with an inlet and an outlet; the mixed solution flows into the cylindrical cell body 17 from the inlet and flows out from the outlet after in-situ reaction with the solid catalyst 19.
[0026] The concentration change waveform of the mixed solution can be any one of a sine wave, a cosine wave, a square wave and a triangular wave, and the embodiments of the present application do not make any limitation.
[0027] In actual application, the in-situ infrared cell can be used together with infrared equipment such as an infrared spectrum detector. Figure 3 is the measured infrared spectrum of cyclohexanol; Figure 4 is a square wave modulation excitation spectrum for the spectral signal at 2980 cm -1 , wherein the period T of the square wave is 240 s.
[0028] In the embodiments of the present application, the infrared crystal 18 can be any one of zinc selenide, silicon, diamond and germanium.
[0029] In actual application, the working temperature of the in-situ infrared cell is generally -20℃-500℃.
[0030] Further, the device further comprises a liquid pump 15 arranged between the mixed solution unit and the in-situ infrared cell; the liquid pump 15 is used to deliver the mixed solution mixed by the mixed solution unit into the in-situ infrared cell.
[0031] Reference Figure 1 As shown, the mixed solution unit comprises a first container 11, a first output pipeline connected to the first container 11, a second container 12, a second output pipeline connected to the second container 12, and a mixed pipeline in communication with the output ends of the first output pipeline and the second output pipeline; the output end of the mixed pipeline is in communication with the input end of the liquid pump 15; the first container 11 contains the first solution; the second container 12 contains the second solution; the first output pipeline is provided with a first valve 13 for controlling the output flow rate of the first solution; the second output pipeline is provided with a second valve 14 for controlling the output flow rate of the second solution. The first valve 13 and / or the second valve 14 can be an electromagnetic valve.
[0032] In the present application, the in-situ infrared device mainly consists of a mixed solution unit, a liquid pump 15 and an in-situ infrared cell. The mixed solution unit in the device mainly controls the mixing of two solutions through an electromagnetic valve control system to form a flow with a certain concentration change within a certain time, thereby forming a periodic signal, and through an infrared spectrum detection device, the signal change rule of the solid catalyst 19 surface in the in-situ infrared cell with the concentration change is detected to obtain a modulation excitation spectrum. The device can realize the modulation excitation spectrum on the total reflection infrared device, and has simple structure and low use cost.
[0033] Further, referring to Figure 1 and Figure 2 As shown, the device further comprises an overflow unit 16, the inlet of the overflow unit 16 is connected with the output end of the liquid pump 15; the outlet of the overflow unit 16 is connected with the liquid inlet of the in-situ infrared cell; the outlet of the overflow unit 16 is flat, and the shape of the outlet of the overflow unit 16 is matched with the shape of the liquid inlet of the in-situ infrared cell. Wherein, the overflow unit 16 can include a containing box 161 and an overflow pipe 162; the first end of the overflow pipe 162 is inserted into the containing box 161 from the bottom end of the containing box 161, and the second end of the overflow pipe 162 is connected with the liquid inlet of the in-situ infrared cell; the sidewall of the containing box 161 is provided with a liquid inlet, and the liquid inlet is connected with the output end of the liquid pump 15. The outlet width L of the overflow unit 16 is equal to the width of the infrared crystal 18.
[0034] The present application sets the overflow unit 16 between the liquid pump 15 and the in-situ infrared cell, since the outlet of the overflow unit 16 is flat and has the same width as the infrared crystal 18, so that it can ensure that the liquid with different concentrations uniformly flows through the surface of the solid catalyst 19.
[0035] In the embodiment of the present application, the in-situ infrared cell further comprises a sealing ring 21, which is used to seal the connection between the cylindrical cell body 17 and the infrared crystal 18, so as to prevent the reaction solution in the cylindrical cell body 17 from leaking from the connection between the cylindrical cell body 17 and the infrared crystal 18. Wherein, the sealing ring 21 can be an O-shaped rubber sealing ring 21.
[0036] The above is only a few embodiments of the present application, and does not limit the present application in any form. Although the preferred embodiments are disclosed as above, they are not intended to limit the present application. Any skilled person in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the technical solution of the present application, which are equivalent to equivalent embodiments and belong to the scope of the technical solution.
Claims
1. An in-situ infrared device based on modulated excitation spectrum, characterized in that, The device includes: The mixing unit is used to mix a first solution with a second solution and to regulate the mixing ratio of the first solution with the second solution so that the concentration of the mixed solution changes periodically; the waveform of the concentration change of the mixed solution is any one of sine wave, cosine wave, square wave, and triangle wave. A liquid pump is used to transport the mixed solution from the mixing unit to the in-situ infrared cell. An in-situ infrared cell includes a cylindrical cell body with an opening at the bottom and an infrared crystal for sealing the opening at the bottom of the cylindrical cell body, as well as a solid catalyst located inside the cylindrical cell body and fixed on the infrared crystal; an infrared beam undergoes total internal reflection within the infrared crystal; an inlet and an outlet are provided on the side wall of the cylindrical cell body; the mixed solution flows into the cylindrical cell body from the inlet, reacts in situ with the solid catalyst, and then flows out from the outlet; The operating temperature of the in-situ infrared cell is -20℃ to 500℃; The device further includes an overflow unit, the inlet of which is connected to the output end of the liquid pump; and the outlet of which is connected to the inlet of the in-situ infrared pool. The outlet of the overflow unit is flat and the shape of the outlet of the overflow unit is adapted to the inlet of the in-situ infrared cell. The outlet width of the overflow unit is equal to the width of the infrared crystal.
2. The apparatus according to claim 1, characterized in that, The liquid pump is located between the mixing unit and the in-situ infrared cell.
3. The apparatus according to claim 2, characterized in that, The mixing unit includes a first container, a first output pipe connected to the first container, a second container, a second output pipe connected to the second container, and a mixing pipe that is connected to the output ends of both the first output pipe and the second output pipe; the output end of the mixing pipe is connected to the input end of the liquid pump. The first container contains a first solution; the second container contains a second solution; A first valve is provided on the first output pipe, and the first valve is used to control the output flow rate of the first solution; A second valve is installed on the second output pipe, and the second valve is used to control the output flow rate of the second solution.
4. The apparatus according to claim 1, characterized in that, The overflow unit includes a container and an overflow pipe; the first end of the overflow pipe is inserted into the container from the bottom end of the container, and the second end of the overflow pipe is connected to the inlet of the in-situ infrared pool. A liquid inlet is provided on the side wall of the container, and the liquid inlet is connected to the output end of the liquid pump.
5. The apparatus according to claim 1, characterized in that, The infrared crystal is any one of zinc selenide, silicon, diamond, and germanium.
6. The apparatus according to claim 3, characterized in that, The first valve and / or the second valve are solenoid valves.
Citation Information
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