In-situ Raman testing device suitable for high-pressure flow type three-phase interface

Abstract

The invention discloses an in-situ Raman testing device suitable for a high-pressure flow type three-phase interface, and belongs to the technical field of optical spectrum instrument accessories and instrument analysis. Comprising a gas chamber, a cathode chamber insulation clamping plate, a cathode chamber, a cover plate, an anode chamber insulation clamping plate, an anode chamber and optical glass. The device is simple to assemble and good in sealing performance, high-quality Raman spectrogram information is easy to obtain, the reaction tank can be embedded in a Raman spectrometer sample table, a solution pipeline is connected with a pressure-controllable balancing device and is connected with an electrochemical workstation and a Raman system, and optical signal testing in a high-pressure flow type three-phase interface environment can be realized. The actual gas diffusion electrode has a good effect in mechanism research and application research of electro-catalysis / photoelectrocatalysis reaction.

Description

Technical Field

[0001] The invention relates to the technical field of spectral instrument accessories and instrument analysis, and more specifically, to an in-situ Raman testing device suitable for a high-pressure flow three-phase interface. Background Art

[0002] In-situ Raman technology is based on the interaction between light and chemical bonds within materials, and has the advantages of simple operation, strong applicability, and non-destructiveness. Since in-situ Raman spectroscopy can directly obtain the fingerprint peaks of reactive species at the molecular level, it can provide detailed information such as the chemical structure, crystallinity, and molecular interactions of the sample, and has become an important research method for characterizing the electrode / electrolyte interface process.

[0003] In the test and research of electrocatalytic reactions using in-situ Raman spectroscopy technology, the in-situ Raman electrochemical cell is required to restore the reaction conditions of electrocatalysis as much as possible, while meeting the needs of in-situ Raman spectroscopy signal acquisition. At present, although there are some Raman reaction cells on the market, whether they are two-phase interface or three-phase interface reaction cells equipped with gas diffusion electrodes, they all adopt normal pressure design, which artificially ignores the large category of reaction systems such as high-pressure reactions, which is quite different from actual industrial production. At present, there are few reports on electrolytic cells that meet the requirements of flow, high pressure and in-situ Raman testing at the same time. Summary of the invention

[0004] In view of the defects of the prior art, the purpose of the present invention is to provide an in-situ Raman testing device suitable for high-pressure flow three-phase interface, aiming to solve the problem of testing the in-situ Raman signal of a high-pressure electrolytic cell under different pressures.

[0005] To achieve the above-mentioned purpose, the present invention provides an in-situ Raman test device suitable for high-pressure flow three-phase interface, comprising a gas chamber, a cathode chamber insulating clamp, a cathode chamber, a cover plate, an anode chamber insulating clamp and an anode chamber, wherein the cathode chamber insulating clamp is located between the gas chamber and the cathode chamber; an air hole is opened in the center of the gas chamber, a gas diffusion electrode is arranged between the cathode chamber insulating clamp and the cathode chamber, and the size of the gas diffusion electrode covers the air hole, the gas chamber comprises an air inlet and an air outlet, most of the gas is directly discharged out of the gas chamber through the air outlet, and a small part of the gas enters the gas diffusion electrode from the air hole to undergo an electrocatalytic reaction; an electrode slot is provided in the cathode chamber, a high-voltage reference electrode is configured, and a liquid inlet is provided in the cathode chamber; the cathode chamber and the cover plate are opened in the center and inlaid with optical glass; the anode chamber insulating clamp and the anode chamber are placed vertically as a whole composed of the gas chamber, the cathode chamber insulating clamp, the cathode chamber and the cover plate; a counter electrode is arranged between the anode chamber insulating clamp and the anode chamber, and the anode chamber has a liquid outlet; a sealing ring groove is provided at the contact part of each component, and a closed pressure-resistant system is formed by fastening with a sealing ring;

[0006] During operation, the electrolyte is introduced through the liquid inlet, flows in the cathode chamber and the anode chamber, and then flows out from the liquid outlet; gas is introduced into the gas chamber, and an electrocatalytic reaction occurs at the gas diffusion electrode. The changes in the gas diffusion electrode reaction are observed through optical glass, and the Raman spectrum signals during the electrocatalytic reaction are collected.

[0007] Furthermore, the air chamber is provided with screw holes for fixing the testing device.

[0008] Furthermore, there is an air inlet in the middle of one side of the air chamber, and an air outlet in the middle of the upper side. Following the bottom-in and top-out principle, the pressurization operation of the test device is achieved through a back pressure valve.

[0009] Further, the sealing ring groove includes an air chamber sealing ring groove connecting the air chamber and the cathode chamber insulating splint, a first sealing ring groove of the cathode chamber insulating splint, a second sealing ring groove of the cathode chamber insulating splint connecting the cathode chamber insulating splint and the cathode chamber, a first sealing ring groove of the cathode chamber, a second sealing ring groove of the cathode chamber insulating splint connecting the cathode chamber and the anode chamber insulating splint, a third sealing ring groove of the cathode chamber connecting the cathode chamber and the cover plate, a fourth sealing ring groove of the cathode chamber connecting the cathode chamber and the optical glass, a first sealing ring groove of the cover plate connecting the cathode chamber and the cover plate, a second sealing ring groove of the cover plate connecting the cover plate and the optical glass, a first sealing ring groove of the anode chamber insulating splint connecting the cathode chamber and the anode chamber insulating splint, a second sealing ring groove of the anode chamber insulating splint connecting the anode chamber insulating splint and the anode chamber, and an anode chamber sealing ring groove connecting the anode chamber insulating splint and the anode chamber.

[0010] Furthermore, each of the sealing ring grooves is an O-ring groove.

[0011] Furthermore, the cathode chamber insulating clamping plate is provided with two sealing ring grooves, which respectively correspond to the air chamber sealing ring groove and the cathode chamber first sealing ring groove.

[0012] Furthermore, the cathode chamber includes a liquid inlet located in the middle and lower part of one side, and a channel for connecting a reference electrode in the middle and upper part of one side, and its thread is national standard M10*1.

[0013] Furthermore, a boss is opened in the cathode chamber cavity with adjustable height. By adjusting the height of the boss, the thickness of the solution between the optical glass and the working electrode can be changed. The fourth sealing ring groove of the cathode chamber can support the optical glass so that it can withstand a certain pressure without breaking. The cavity is the area where the catalytic reaction occurs.

[0014] Furthermore, the first sealing ring groove of the cover plate corresponds to the third sealing ring groove of the cathode chamber, the second sealing ring groove of the cover plate can receive the optical glass, and the height of the cylindrical boss of the cover plate can be adjusted according to the thickness of the optical glass.

[0015] Furthermore, the first sealing ring groove of the anode chamber insulating clamp corresponds to the second sealing ring groove of the cathode chamber, the anode chamber insulating clamp cavity corresponds to the cathode chamber cavity, which is a channel for liquid flow, and the second sealing ring groove of the anode chamber insulating clamp corresponds to the anode chamber sealing ring groove.

[0016] Furthermore, a counter electrode is placed in the cavity of the anode chamber, and liquid flows into the cathode chamber and flows out of the anode chamber, and liquid circulation is achieved through a high-pressure circulation pump.

[0017] Furthermore, the diameter of the optical glass is slightly larger than the diameter of the cylindrical boss of the cover plate, and the optical glass is made of quartz glass or transparent sapphire.

[0018] Furthermore, the cathode chamber insulating clamping plate and the anode chamber insulating clamping plate are made of PTFE, and the gas chamber, cathode chamber, cover plate and anode chamber are all made of stainless steel or titanium alloy.

[0019] Furthermore, the cathode chamber and the cover plate fix the optical glass through sealing rings and screws, the optical window is located in the center of the electrolytic cell, the gas chamber, the cathode chamber insulating clamp, the cathode chamber, the optical glass, and the cover plate are fastened and connected with screws and bolts, and the cathode chamber, the anode chamber insulating clamp and the anode chamber are fastened and connected with screws and bolts.

[0020] Through the above technical scheme conceived by the present invention, compared with the prior art, the high-pressure flow three-phase interface Raman electrochemical cell of the present invention meets the actual needs of studying the microscopic mechanism of electrocatalytic reaction of the three-phase interface under high-pressure system, and fills the gap of high-pressure flow three-phase interface reactor. Among them, the reasonable application of stainless steel or titanium alloy material and sealing ring groove meets the pressure resistance requirement of the reaction cell; by adding grooves inside the cathode chamber cavity and boss design, the thickness of the electrolyte can be flexibly adjusted to adapt to the optical characteristics of the Raman spectrometer, and a high signal-to-noise ratio Raman signal can be obtained in different pressure ranges. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the original Raman testing device for the high-pressure flow three-phase interface in the present invention.

[0022] Figure 2 It is a schematic diagram of the positions and connection relationships of the gas chamber, the insulating clamping plate between the gas chamber and the cathode chamber, the cathode chamber, the optical glass and the cover plate.

[0023] Figure 3 It is a schematic diagram of the position and connection relationship of the cathode chamber, the insulating clamp between the cathode chamber and the anode chamber, and the anode chamber.

[0024] Figure numerals: 1: air chamber; 2: cathode chamber insulating plate; 3: cathode chamber; 4: cover plate; 5: anode chamber insulating plate; 6: anode chamber; 7: optical glass; 1-1: air inlet; 1-2: air hole; 1-3: air chamber sealing ring groove; 1-4: air outlet; 2-1: first sealing ring groove of cathode chamber insulating plate; 2-2: second sealing ring groove of cathode chamber insulating plate; 3-1: liquid inlet; 3-2: high voltage reference electrode; 3-3: first sealing ring groove of cathode chamber; 3-4: The third sealing ring groove of the cathode chamber; 3-5: boss; 3-6: the fourth sealing ring groove of the cathode chamber; 3-7: the cathode chamber cavity; 3-8: the second sealing ring groove of the cathode chamber; 3-9: the solution flow channel of the cathode chamber; 4-1: the first sealing ring groove of the cover plate; 4-2: the second sealing ring groove of the cover plate; 4-3: the cylindrical boss of the cover plate; 5-1: the first sealing ring groove of the insulating clamping plate of the anode chamber; 5-2: the second sealing ring groove of the insulating clamping plate of the anode chamber; 6-1: the sealing ring groove of the anode chamber; 6-2: the liquid outlet. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with 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 intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0026] The present invention provides an in-situ Raman testing device suitable for high-pressure flow three-phase interface, such as Figure 1 As shown, it includes a gas chamber 1, a cathode chamber insulating clamp plate 2, a cathode chamber 3, a cover plate 4, an anode chamber insulating clamp plate 5 and an anode chamber 6, wherein the cathode chamber insulating clamp plate 2 is located between the gas chamber 1 and the cathode chamber 3; a gas hole 1-2 is opened in the center of the gas chamber 1, a gas diffusion electrode is arranged between the cathode chamber insulating clamp plate and the cathode chamber, and the size of the gas diffusion electrode covers the gas hole 1-2, the gas chamber 1 includes an inlet hole 1-1 and an outlet hole 1-4, most of the gas is directly discharged from the gas chamber 1 through the outlet hole 1-4, and a small part of the gas enters the gas diffusion hole from the air hole 1-2 An electrocatalytic reaction occurs at the electrode; the cathode chamber 3 is provided with an electrode slot, equipped with a high-voltage reference electrode, and the cathode chamber 3 is provided with a liquid inlet 3-1; the cathode chamber 3 and the cover plate 4 are centrally opened and inlaid with an optical glass 7; the anode chamber insulating clamp 5 and the anode chamber 6 are placed vertically at 90 degrees to the whole composed of the gas chamber 1, the cathode chamber insulating clamp 2, the cathode chamber 3, and the cover plate 4; a counter electrode is provided between the anode chamber insulating clamp 5 and the anode chamber 6, and the anode chamber 6 is provided with a liquid outlet 6-2; the contact parts of each component are provided with a sealing ring groove, which is fastened by the sealing ring to form a closed pressure-resistant system;

[0027] During operation, electrolyte is introduced through the liquid inlet 3-1, flows in the cathode chamber 3 and the anode chamber 6, and then flows out from the liquid outlet 6-2; gas is introduced into the gas chamber 1, and an electrocatalytic reaction occurs at the gas diffusion electrode. The changes in the gas diffusion electrode reaction are observed through the optical glass 7, and the Raman spectrum signal during the electrocatalytic reaction is collected.

[0028] Figure 2 It is a schematic diagram of the positions and connection relationships of the gas chamber 1, the insulating clamping plate 2 between the gas chamber 1 and the cathode chamber, the cathode chamber 3, the optical glass 7 and the cover plate 4.

[0029] Figure 3 It is a schematic diagram of the position and connection relationship between the cathode chamber 3, the anode chamber insulating clamp 5 and the anode chamber 6.

[0030] Example

[0031] In order to discharge bubbles as quickly as possible and reduce the influence of gas on experimental testing, the test device of the present invention is arranged vertically. From front to back, the reaction cell parts are the cover plate, optical glass, cathode chamber, cathode chamber and cathode chamber insulating clamp, and gas chamber. From left to back, the reaction cell parts are the cathode chamber, anode chamber insulating clamp, and anode chamber. The light beam of the Raman spectrometer matched with the electrolytic cell device of this embodiment can be projected from the optical glass into the cathode chamber of the electrochemical cell, and the Raman scattering signal is obtained by reflection of the sample under test on the working electrode.

[0032] The inside of the electrolytic cell is provided with a reference electrode and pipe threads. The gas circuit, liquid circuit and high-pressure reference electrode are screwed in from the outside to the inside through one side of the reaction cell body by means of threaded connection to achieve stability under high pressure environment. There are sealing ring grooves between each reaction cell part to play a sealing role. The material of stainless steel or titanium alloy and the reasonable application of sealing rings meet the pressure resistance requirements of the reaction cell. By increasing the grooves inside the cathode chamber cavity and the boss design, the thickness of the electrolyte can be flexibly adjusted to adapt to the optical characteristics of the Raman spectrometer, and a high signal-to-noise ratio Raman signal can be obtained within different pressure ranges.

[0033] In this embodiment, the in-situ Raman testing device detection method for high-pressure flow three-phase interface includes the following steps:

[0034] (1) The in-situ Raman testing device is placed on a reaction pool support table of a Raman testing system;

[0035] (2) Install the gas diffusion electrode, high-voltage reference electrode and counter electrode respectively, and connect the high-voltage pipeline;

[0036] (3) During the electrocatalytic reaction, CO or CO2 gas is introduced into the gas chamber at a gas flow rate of 20 sccm, and 10 mL of electrolyte is introduced into the cathode chamber and the anode chamber respectively. A high-pressure peristaltic pump is used to circulate the electrolyte between the cathode chamber and the anode chamber at a liquid flow rate of 10 mL / min. The alligator clips of the electrochemical workstation are connected to the counter electrode, high-voltage reference electrode, and gas diffusion electrode respectively, and the electrochemical workstation parameters are set;

[0037] (4) Observe the progress of the electrode surface reaction through optical glass and collect Raman spectral signals during the electrocatalytic reaction.

[0038] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An in-situ Raman testing device suitable for high-pressure flow three-phase interface, characterized in that: The invention comprises an air chamber (1), a cathode chamber insulating clamp (2), a cathode chamber (3), a cover plate (4), an anode chamber insulating clamp (5) and an anode chamber (6); the cathode chamber insulating clamp (2) is located between the air chamber (1) and the cathode chamber (3); an air hole is opened in the center of the air chamber (1); a gas diffusion electrode is arranged between the cathode chamber insulating clamp (2) and the cathode chamber (3); the size of the gas diffusion electrode covers the air hole; the air chamber (1) comprises an air inlet (1-1) and an air outlet (1-4); most of the gas is directly discharged out of the air chamber through the air outlet (1-4); a small part of the gas enters the gas diffusion electrode through the air hole An electrocatalytic reaction occurs; the cathode chamber (3) is provided with an electrode slot and a high-voltage reference electrode, and the cathode chamber (3) is provided with a liquid inlet (3-1); the cathode chamber (3) and the cover plate (4) are centrally opened and inlaid with optical glass (7); the anode chamber insulating clamp (5) and the anode chamber (6) are vertically arranged as a whole with the gas chamber (1), the cathode chamber insulating clamp (2), the cathode chamber (3), and the cover plate (4); a counter electrode is provided between the anode chamber insulating clamp (5) and the anode chamber (6), and the anode chamber (6) is provided with a liquid outlet (6-2); the contact parts of the various components are provided with sealing ring grooves, which are fastened by sealing rings to form a closed pressure-resistant system; During operation, an electrolyte is introduced through the liquid inlet (3-1), flows in the cathode chamber (3) and the anode chamber (6), and then flows out from the liquid outlet (6-2); a gas is introduced into the gas chamber (1), an electrocatalytic reaction occurs at the gas diffusion electrode, the reaction changes of the gas diffusion electrode are observed through the optical glass (7), and the Raman spectrum signal during the electrocatalytic reaction is collected.

2. The device according to claim 1, characterized in that The pressurization of the air chamber is achieved through a back pressure valve.

3. The device according to claim 1, characterized in that A boss (3-5) is provided in the middle of the cathode chamber (3) for receiving optical glass.

4. The device according to claim 1, characterized in that Liquid circulation is achieved by a high-pressure circulation pump.

5. The device according to claim 1, characterized in that The sealing ring groove comprises an air chamber sealing ring groove (1-3) connecting the air chamber (1) and the cathode chamber insulating clamping plate (2), a first sealing ring groove (2-1) of the cathode chamber insulating clamping plate, a second sealing ring groove (2-2) of the cathode chamber insulating clamping plate connecting the cathode chamber insulating clamping plate (2) and the cathode chamber (3), a first sealing ring groove (3-3) of the cathode chamber, a second sealing ring groove (3-8) of the cathode chamber connecting the cathode chamber (3) and the anode chamber insulating clamping plate (5), a third sealing ring groove (3-4) of the cathode chamber connecting the cathode chamber (3) and the cover plate (4), a sealing ring groove (3-5) of the cathode chamber connecting the cathode chamber (3) and the optical glass The invention relates to a cathode chamber fourth sealing ring groove (3-6) of the optical glass (7), a cover plate first sealing ring groove (4-1) connecting the cathode chamber (3) and the cover plate (4), a cover plate second sealing ring groove (4-2) connecting the cover plate (4) and the optical glass (7), an anode chamber insulating clamping plate first sealing ring groove (5-1) connecting the cathode chamber (3) and the anode chamber insulating clamping plate (5), an anode chamber insulating clamping plate second sealing ring groove (5-2) connecting the anode chamber insulating clamping plate (5) and the anode chamber (6), and an anode chamber sealing ring groove (6-1) connecting the anode chamber insulating clamping plate (5) and the anode chamber (6).

6. The device according to claim 5, characterized in that The sealing ring grooves are all O-ring grooves.

7. The device according to claim 1, characterized in that The high voltage reference electrode is one or more of a silver chloride electrode, a Hg / HgO mercuric oxide electrode and a saturated calomel cell.

8. The device according to claim 1, characterized in that The gas chamber (1), cathode chamber (3), cover plate (4) and anode chamber (6) are all made of stainless steel or titanium alloy.

Images