Electrochemical three-phase interface in-situ surface enhanced total reflection infrared spectrum detection system

Abstract

The invention discloses an electrochemical three-phase interface in-situ surface enhanced total reflection infrared spectrum detection system which comprises an infrared spectrometer, a reflecting crystal, an H-shaped reaction tank, an aeration device, a gas bottle, an electrochemical workstation and a data recording computer, the H-type reaction tank and the reflecting crystal are assembled through accessories and are put into the infrared spectrometer, the gas bottle is connected with the aeration device through the rubber tube and is led into a tank body of the H-type reaction tank, three electrodes of the H-type reaction tank are respectively clamped by electrode clamps of the electrochemical workstation, and during testing, a light path is checked and data are recorded through the data recording computer. The reflection angle of the crystal is adjusted until the signal intensity is stable, and the three-phase interface of the catalytic material is detected by adopting an MCT detector. The infrared detection sensitivity is improved through the surface plasma resonance effect, the dynamic change of a gas-liquid-solid three-phase interface in the electrochemical reaction process can be monitored in real time, and important data support is provided for reaction mechanism research; wide application prospects are realized.

Description

Technical Field

[0001] The present invention belongs to the field of electrochemical characterization technology, and particularly relates to a system based on in-situ surface-enhanced total reflection infrared spectroscopy (SEIRAS), which is used for high-sensitivity, real-time dynamic detection of changes in the gas-liquid-solid three-phase interface during electrochemical reactions. The system can be applied to the mechanism research of electrocatalytic reactions, especially the interface processes in complex reactions such as methane oxidation and carbon dioxide reduction. Background Art

[0002] Electrocatalytic reactions have wide applications in multiple industrial and energy fields, such as hydrogen production, fuel cells, and carbon dioxide reduction reactions. The efficiency and selectivity of electrocatalytic reactions are usually limited by the reaction processes occurring at the gas-liquid-solid three-phase interface. However, traditional characterization techniques make it difficult to monitor the dynamic changes of the three-phase interface in real time, especially when the gas is involved in the reaction. Therefore, developing a characterization method that can monitor the three-phase interface in real time and sensitively during the electrochemical reaction is of great significance for a deep understanding of the electrocatalytic reaction mechanism.

[0003] Surface-enhanced total reflection infrared spectroscopy (SEIRAS) is a technique that uses the metal surface plasma enhancement effect to significantly increase the infrared signal intensity at the interface. This method can detect the molecular vibration information on the electrode surface with high sensitivity. Combined with the design of the in-situ electrochemical reaction cell, it can capture the interface changes during the reaction in real time, especially the dynamic reaction process of the gas-liquid-solid three-phase. Summary of the invention

[0004] The present invention aims to provide an in-situ surface-enhanced total reflection infrared spectroscopy system capable of highly sensitive and real-time dynamic detection of electrochemical three-phase interfaces. Through innovative reaction tank design and aeration device system, uniform diffusion of gas is achieved to ensure the formation of a stable gas-liquid-solid three-phase interface on the electrode surface, thereby significantly improving the intensity and resolution of spectral signals. The system is suitable for studying multiphase electrocatalytic reactions such as methane oxidation and carbon dioxide reduction.

[0005] The technical solution adopted by the present invention is an in-situ surface enhanced total reflection infrared spectroscopy system for highly sensitive dynamic detection of electrochemical three-phase interface, including an infrared spectrometer, a reflection crystal, an H-type reaction cell, an aeration device, a gas bottle, an electrochemical workstation and a data recording computer, and the electrolyte and gas are specifically determined by the system. The H-type reaction cell and the reflection crystal are assembled through accessories and placed in the infrared spectrometer, the gas bottle is connected to the aeration device through a rubber tube and passed into the cell body, the electrode clamps of the electrochemical workstation are respectively clamped on the three electrodes of the reaction cell, the optical path is checked and the data is recorded through the data recording computer during the test, and the three-phase interface of the catalytic material is detected by adjusting the crystal reflection angle to a stable signal intensity (60-65°). The Mercury cadmium telluride (MCT) detector is used.

[0006] Furthermore, the three electrodes of the H-type reaction cell are: a working electrode, a reference electrode and a counter electrode. The in-situ reaction cell is the core component of the system, specifically:

[0007] (1) H-type reaction cell: The design of the H-type cell can ensure the separation of different electrode reactions and the independence of the solution environment, thereby enhancing the sensitivity and accuracy of in-situ electrochemical infrared detection.

[0008] Working electrode: a crystal plated with a Ni-based bimetallic layer (such as a gold-plated silicon crystal), used to enhance the infrared signal strength. The working electrode is in contact with the gas phase, liquid phase and solid phase at the same time, forming a gas-liquid-solid three-phase interface. The specific preparation method of this electrode is:

[0009] Select silicon crystals coated with gold / gold-silver film as the substrate. The function of the gold / gold-silver film is to enhance the infrared signal, so it is necessary to ensure that the gold-plated layer is uniform and of appropriate thickness. In the magnetron sputtering equipment, Ni-M targets (M=Cu, Mn, Ti, V) are loaded into the target positions respectively. Use argon as the sputtering gas, and adjust the equipment parameters such as sputtering voltage, gas pressure and gas flow to ensure that the deposition thickness is precisely controllable. Before sputtering, the gold-plated silicon crystal substrate is cleaned with a plasma cleaner to remove surface contaminants. Then, the cleaned substrate is placed on the sample stage of the magnetron sputtering equipment. Select sputtering conditions to form a Ni-M bimetallic layer with a thickness of 50nm. During the sputtering process, keep the target stable and the substrate rotate evenly to ensure uniform deposition.

[0010] Specific sputtering parameters:

[0011] Ni-Cu: sputtering voltage: 28; sputtering gas pressure: 5.4pa; gas flow rate: 30SCCM;

[0012] Ni-Mn: sputtering voltage: 32; sputtering gas pressure: 5.8pa; gas flow rate: 30SCCM;

[0013] Ni-Ti: sputtering voltage: 30; sputtering gas pressure: 5.6pa; gas flow rate: 30SCCM;

[0014] Ni-V: sputtering voltage: 30; sputtering gas pressure: 5.6pa; gas flow rate: 30SCCM;

[0015] In the in-situ three-phase infrared detection, the gold-coated silicon crystal coated with Ni-based bimetallic layer utilizes the surface plasmon resonance effect of the gold / gold-silver film to enhance the infrared signal, and combines it with the active sites provided by the bimetallic layer to achieve high-sensitivity infrared detection.

[0016] (2) Reference electrode and counter electrode: Hg / HgO is used as the reference electrode and platinum electrode is used as the counter electrode to form a standard three-electrode system for potential control and monitoring during electrochemical reactions.

[0017] Furthermore, the gas diffusion system is provided with an aeration device hole at the top of the reaction tank for introducing gas. The aeration device ensures uniform distribution of gas, avoids local oversaturation of gas or bubble retention, thereby enhancing the dissolution and diffusion of gas on the electrode surface. The gas is uniformly introduced into the reaction tank through the aeration device, and the diffusion and dissolution of the gas are controlled in real time by the in-situ monitoring system to ensure that the gas participates in the reaction process.

[0018] Furthermore, the surface enhancement technology uses surface plasma enhancement technology to coat a layer of Au / AuAg film on the surface of the working electrode, and deposits the catalyst on the metal surface by magnetron sputtering technology.

[0019] Furthermore, an infrared spectroscopy detection system was used to explore the reaction mechanism. The infrared spectrometer was used to collect molecular vibration information on the surface of the working electrode. Through the design of the in-situ reaction cell, infrared light can directly penetrate the electrolyte and gas phase and irradiate the electrode surface, realizing dynamic monitoring of the gas-liquid-solid three-phase interface.

[0020] Furthermore, in the in-situ infrared detection, the key reaction intermediates are identified by monitoring the characteristic peak changes of active species on the Ni-based bimetallic surface. By comparing the changes in the infrared spectrum under different potential conditions, the metal sites with different oxidation states and their interactions with the intermediates can be qualitatively identified.

[0021] In-situ infrared detection monitors the generation and disappearance of intermediates and products by collecting real-time infrared spectra at different potentials. Combined with electrochemical information, the reaction paths of different intermediates and their interaction mechanisms with the active sites on the catalyst surface can be further inferred.

[0022] In-situ infrared detection is used to analyze the double-layer structure of the electrode surface and its characteristics that change with the reaction potential. On the electrode surface, water molecules and adsorbed ions form an ordered structure induced by the electric field. By monitoring the changes in OH stretching vibrations in the infrared spectrum, the arrangement of hydrogen bonds of water molecules is analyzed, and the effect of changes in the interfacial electric field strength on the electrochemical reaction process is inferred.

[0023] How the system works:

[0024] Preparation and coating of S1 reflective crystal

[0025] 1) The surface of the reflective crystal is first coated with a layer of gold / gold-silver film to enhance the infrared signal. This step is the basis for the operation of the entire system. The coating of the gold / gold-silver film is to utilize the surface plasmon resonance (SPR) effect of the metal to enhance the infrared signal.

[0026] 2) The working electrode is installed at the bottom of the reaction cell and connected to the counter electrode and reference electrode through the electrolyte to ensure the basic setting of the electrochemical reaction and lay the foundation for the subsequent gas introduction.

[0027] S2 gas and electrolyte management

[0028] 1) Gas is continuously introduced through the aeration device to ensure that the gas concentration and solubility in the reaction tank are maintained at the highest level. For example, in the methane oxidation experiment, CH4 gas is introduced into the reaction tank for 20 minutes to saturate the electrolyte to increase the efficiency of methane participating in the reaction on the electrode surface.

[0029] 2) This step makes the gas and electrolyte in the reaction cell in the optimal state, providing the necessary conditions for the next step of real-time infrared spectrum monitoring.

[0030] Real-time monitoring of S3 infrared spectrum

[0031] 1) During the electrochemical reaction, the infrared spectrometer monitors the vibration signals of the molecules on the working electrode surface in reflection mode. The dynamic changes of the gas-liquid-solid three-phase interface are shown by infrared spectra at different potentials.

[0032] 2) By adjusting the reaction potential (e.g., 1.1 V to 1.8 V), the system is able to capture the generation, transformation, and disappearance of active intermediates in the reaction. The output of this step is real-time infrared spectroscopy data, which will be used to analyze and understand the dynamic mechanism of the electrocatalytic reaction.

[0033] S4 Analysis and interpretation of data

[0034] 1) By analyzing the infrared spectra at different potentials and times, we can obtain information about the adsorption changes of organic matter at the three-phase interface during the electrocatalytic reaction and achieve in-situ monitoring.

[0035] 2) This step analyzes the real-time data collected in step 3 to reveal the dynamic mechanism of the electrocatalytic reaction and provide a scientific basis for further research and optimization.

[0036] Compared with the prior art, the present invention has the following significant advantages:

[0037] 1. Application of surface enhanced total reflection infrared spectroscopy (SEIRAS) technology.

[0038] It has high sensitivity. Through surface enhanced infrared technology, the detection sensitivity of molecular vibration signals at the three-phase interface is significantly improved, and changes in trace reactants can be captured.

[0039] Au / AuAg, which has excellent electrochemical stability and certain catalytic effect on oxidation reactions, is used as the plasma resonance matrix. The multi-wavelength tunable SPR characteristics of mesoporous gold are used to construct in-situ surface-enhanced infrared spectroscopy, thereby realizing wide-area detection of the electrocatalytic three-phase interface. This technology enables the system to perform highly sensitive detection of molecular vibration information on the electrode surface, which is difficult to achieve with many traditional technologies.

[0040] 2. Real-time monitoring

[0041] The system uses an in-situ monitoring system to perform real-time control to ensure that the gas participates in the reaction process and captures the dynamic changes of the three-phase interface on the electrode surface in real time during the reaction. This real-time monitoring capability provides real-time data for the mechanism research of complex electrocatalytic reactions, which is difficult to provide with traditional technologies.

[0042] 3. Addition of aeration system

[0043] The aeration device is designed to ensure uniform gas diffusion and the electrode surface is in contact with the gas phase, liquid phase and solid phase at the same time. This design overcomes the limitations of the traditional two-phase detection method and allows a more comprehensive study of the three-phase interface reaction mechanism. The system can accurately control the gas flow rate to avoid interference with the reaction caused by excessive or insufficient gas. This precise control is essential to ensure the uniformity and repeatability of the reaction.

[0044] 4. The system structure is simple and easy to operate

[0045] The system of the present invention has simple design, convenient operation, and can be easily integrated into existing electrochemical and spectral equipment, and has good practicality and scalability. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1The overall schematic diagram of the in-situ surface-enhanced total reflection infrared spectroscopy system of the present invention shows the structural layout of the total reflection infrared internal reaction cell, electrochemical workstation, etc. 1. Data recording calculator 2. Mercury cadmium telluride (MCT) detector 3. Reaction cell device 4. Infrared laser 5. Gas cylinder 6. Electrochemical workstation.

[0047] Figure 2 Schematic diagram of the internal structure of the reaction tank, showing the specific layout of the aeration device, working electrode, reference electrode and counter electrode.

[0048] Figure 3 The following are the scanning electron microscope and transmission electron microscope images of the working electrode using Ni-Cu as an example. Figure a is a schematic diagram of the internal structure of the reaction cell, showing the specific layout of the gas diffusion tube, working electrode, reference electrode and counter electrode. Electron microscope images of the mesoporous gold substrate electrode of this system. Figure a is a 2μm resolution scanning electron microscope image, Figure b is a 500nm resolution scanning electron microscope image, and Figure c is a 5nm resolution transmission electron microscope image.

[0049] Figure 4 This is a data graph of the system used in Example 1 for in situ monitoring of active sites and adsorbed intermediates at the three-phase interface of electrocatalytic methane oxidation at different potentials.

[0050] Figure 5 This is a data graph of the system used in Example 1 for in-situ monitoring of active sites and adsorbed intermediates at the three-phase interface of electrocatalytic methane oxidation at different times.

[0051] Figure 6 This is a data graph of the system used in Example 2 at different potentials for in situ monitoring of active sites and adsorbed intermediates at the three-phase interface of electrocatalytic carbon dioxide reduction. DETAILED DESCRIPTION

[0052] The technical solution of the present invention is further illustrated and described below through specific implementation modes in combination with the accompanying drawings.

[0053] Example 1

[0054] (1) Preparation of Ni-M working electrode.

[0055] A thin layer of gold is plated on the surface of the silicon crystal by a plasma gold spraying instrument, and then a layer of Ni-Cu bimetallic catalytic material is sputtered on the surface of the crystal by a magnetron sputtering method to obtain a working electrode ( Figure 3 ).

[0056] (2) Fix the crystal to the bottom of the accessory and assemble the H-type reaction cell on top, install the Hg / HgO reference electrode and Pt counter electrode, inject the electrolyte and connect the gas cylinder.

[0057] (3) Turn on the infrared spectrometer and electrochemical workstation, place the electrolytic cell on the infrared spectrometer test accessories, connect the wires of the electrochemical workstation, and prepare to start the test. First, check whether the optical path is open and confirm that the detector is an MCT detector. Determine the optimal test amplitude value in the interference pattern by adjusting the reflection angle.

[0058] (4) Parameter settings

[0059] The potential range of the oxidation reaction is 1.1 to 1.8 V. Constant current polarization is used during the test, starting from 1.1 V, with an interval of 0.1 V each time until 1.8 V. The electrolyte uses a 0.1M KOH solution. After measuring the background, the infrared spectrometer and electrochemical polarization are performed simultaneously. After the test, the polarization is turned off. By analyzing the infrared spectra at different potentials and different times, the adsorption changes of organic matter at the three-phase interface during the electrocatalytic reaction can be obtained, and in-situ monitoring can be achieved.

[0060] The operation of testing the reduction reaction is similar to the above. The electrolyte is 0.2M KHCO3 solution, the potential range is -0.2 to -1.2V, and constant current polarization is used during the test. The test and polarization are carried out simultaneously. After the test, the polarization is turned off.

[0061] Example 2

[0062] Taking the methane oxidation reaction (CH4OR) as an example, the CH4OR data analysis on Ni-Cu was performed. Figure 4 , Figure 5 )

[0063] pass Figure 4 The analysis data shows that at 600-800cm -1 In the lower wave number range, as the potential increases, the Ni and Cu surfaces are gradually oxidized to form Ni and Cu oxide layers, and these changes are reflected in the changes in the absorption peaks. -1 In the wavenumber range, when the potential increases, the CO absorption peak increases, indicating that more methane oxidation products and transition intermediates (such as methanol or aldehyde intermediates) are generated at higher potentials. -1 In the wave number range, the absorption peak of this band increases significantly with the increase of potential, indicating that with the increase of potential, the oxidation reaction of methane molecules is accelerated, and methane and methanol products are oxidized to generate more oxygen-containing intermediates (such as carboxylic acids or ketones). These C=O intermediates are more easily generated at higher potentials. The changes in this part clearly reflect the gradual accumulation of intermediate species during the methane oxidation process.

[0064] exist Figure 5From the analysis of the data in the time spectrum, it can be seen that in the initial period of time, OH- is gradually adsorbed on the catalyst surface, which is the prerequisite for electrochemical reactions in an alkaline environment. At this time, methane molecules begin to adsorb on the catalyst surface, but no significant oxidation reaction has occurred. As time goes on, methane is gradually oxidized to methanol, which is reflected in the 1500-1700cm-1 (C=O stretching vibration) and 1000-1200cm-1 (CO stretching vibration) bands. The absorption peak of methanol as the main oxidation product gradually increases, indicating that the selective oxidation of methane in this process is high. At this stage, because the potential is in a more suitable range, methanol is the main product and less by-products are generated. This shows that the Ni-Cu catalyst has good selectivity for methane under this condition.

[0065] Example 3

[0066] Taking the carbon dioxide reduction reaction (CO2RR) as an example, the CO2RR data analysis on Cu-based catalysts was performed ( Figure 6 )

[0067] In situ infrared spectroscopy tests of Cu catalysts for carbon dioxide reduction reaction (CO2RR) showed the generation and evolution of different species during the reaction. During the CO2RR process, the Cu-NH2R-modified Cu catalyst showed a strong adsorption capacity for *COOH intermediates, which reduced the energy barrier for the generation of CO, while generating HCOOH through *OCHO. The relevant absorption peaks in the infrared spectrum (such as the HCOOH generation related peaks from 1380cm-1 to 1398cm-1) gradually increased with increasing potential, indicating that the catalyst generated more oxygen-containing intermediates at different potentials.

[0068] The above is only a preferred embodiment of the present invention, and does not limit the method scheme of the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the essence of the method of the present invention shall fall within the protection scope of the present invention.

Claims

1. Electrochemical three-phase interface in-situ surface-enhanced total reflection infrared spectroscopy detection system, characterized in that: The invention comprises an infrared spectrometer, a reflection crystal, an H-type reaction cell, an aeration device, a gas bottle, an electrochemical workstation and a data recording computer; the H-type reaction cell and the reflection crystal are assembled through accessories and put into the infrared spectrometer, the gas bottle is connected to the aeration device through a rubber tube and introduced into the cell body of the H-type reaction cell, the electrode clamps of the electrochemical workstation are respectively clamped on the three electrodes of the H-type reaction cell, the optical path is checked and data is recorded through the data recording computer during the test, the crystal reflection angle is adjusted until the signal strength is stable, and the three-phase interface of the catalytic material is detected by the MCT detector.

2. The electrochemical three-phase interface in-situ surface-enhanced total reflection infrared spectroscopy detection system according to claim 1 is characterized in that: The three electrodes of the H-type reaction cell are: working electrode, reference electrode and counter electrode. Specifically: (1) Working electrode: a crystal plated with a Ni-based bimetallic layer, used to enhance the infrared signal strength; the working electrode is in contact with the gas phase, liquid phase and solid phase at the same time, forming a gas-liquid-solid three-phase interface. The specific preparation method of this electrode is as follows: A silicon crystal coated with a gold / gold-silver film is selected as a substrate; the role of the gold / gold-silver film is to enhance infrared signals; in a magnetron sputtering device, Ni-M targets (M=Cu, Mn, Ti, V) are respectively loaded into the target positions; argon is used as a sputtering gas, and the device parameters, including sputtering voltage, gas pressure and gas flow rate, are adjusted to ensure that the deposition thickness is accurately controllable; before sputtering, the gold-coated silicon crystal substrate needs to be cleaned with a plasma cleaning agent to remove surface contaminants; Then, the cleaned substrate was placed on the sample stage of the magnetron sputtering equipment; appropriate sputtering conditions were selected to form a 50nm thick Ni-M bimetallic layer, and the target was kept stable and the substrate was rotated evenly during the sputtering process to ensure uniform deposition; Specific sputtering parameters: Ni-Cu: sputtering voltage: 28; sputtering gas pressure: 5.4pa; gas flow rate: 30SCCM; Ni-Mn: sputtering voltage: 32; sputtering gas pressure: 5.8pa; gas flow rate: 30SCCM; Ni-Ti: sputtering voltage: 30; sputtering gas pressure: 5.6pa; gas flow rate: 30SCCM; Ni-V: sputtering voltage: 30; sputtering gas pressure: 5.6pa; gas flow rate: 30SCCM; In the in-situ three-phase infrared detection, the gold-coated silicon crystal coated with Ni-based bimetallic layer uses the surface plasmon resonance effect of the gold / gold-silver film to effectively enhance the infrared signal, and combines the active sites provided by the bimetallic layer to achieve high-sensitivity infrared detection; (2) Reference electrode and counter electrode: Hg / HgO is used as the reference electrode and platinum electrode is used as the counter electrode to form a standard three-electrode system for potential control and monitoring during electrochemical reactions.

3. The electrochemical three-phase interface in-situ surface-enhanced total reflection infrared spectroscopy detection system according to claim 1 is characterized in that: An aeration device hole is provided on the top of the H-type reaction tank for introducing CH4 or O2 gas; the aeration device ensures uniform distribution of gas to avoid local oversaturation of gas or bubble retention, thereby enhancing the dissolution and diffusion of gas on the electrode surface; the gas is uniformly introduced into the H-type reaction tank through the aeration device, and the diffusion and dissolution of the gas are controlled in real time by the in-situ monitoring system to ensure that the gas participates in the reaction process.

4. The electrochemical three-phase interface in-situ surface-enhanced total reflection infrared spectroscopy detection system according to claim 1, characterized in that: Surface enhanced technology uses surface plasma enhanced technology to coat a layer of Au / AuAg film on the surface of the working electrode and deposit the catalyst on the metal surface through magnetron sputtering technology.

5. The electrochemical three-phase interface in-situ surface-enhanced total reflection infrared spectroscopy detection system according to claim 1, characterized in that: An infrared spectroscopy detection system was used to explore the reaction mechanism. The infrared spectrometer was used to collect molecular vibration information on the surface of the working electrode. Through the design of the in-situ reaction cell, infrared light directly penetrated the electrolyte and gas phase and irradiated the electrode surface, realizing dynamic monitoring of the gas-liquid-solid three-phase interface.

6. The electrochemical three-phase interface in-situ surface-enhanced total reflection infrared spectroscopy detection system according to claim 1, characterized in that: In the in-situ infrared detection, the key reaction intermediates are identified by monitoring the characteristic peak changes of active species on the Ni-based bimetallic surface; by comparing the changes of infrared spectra under different potential conditions, the metal sites with different oxidation states and their interactions with the intermediates can be qualitatively identified; An important application of in situ infrared detection is to reveal the dynamic mechanism of the reaction; By collecting real-time infrared spectra at different potentials, the generation and disappearance of intermediates and products can be monitored; Combined with electrochemical information, the reaction paths of different intermediates and their interaction mechanisms with active sites on the catalyst surface can be inferred; In situ infrared detection is used to analyze the double-layer structure of the electrode surface and its characteristics that change with reaction potential. On the electrode surface, water molecules and adsorbed ions form an ordered structure induced by the electric field. By monitoring the changes in OH stretching vibrations in the infrared spectrum, the arrangement of hydrogen bonds of water molecules is analyzed, and the effect of changes in interfacial electric field strength on the electrochemical reaction process can be inferred.

7. The electrochemical three-phase interface in-situ surface-enhanced total reflection infrared spectroscopy detection system according to claim 1, characterized in that: The system works as follows: Preparation and coating of S1 reflective crystal; 1) The surface of the reflective crystal is first coated with a layer of gold / gold-silver film to enhance the infrared signal; the coating of the gold / gold-silver film utilizes the surface plasma resonance effect of the metal to enhance the infrared signal; 2) The working electrode is installed at the bottom of the reaction cell and connected to the counter electrode and the reference electrode through the electrolyte; Management of S2 gas and electrolyte; 1) Gas is continuously input through the aeration device to ensure that the gas concentration and solubility in the reaction tank are maintained at the highest level; 2) To achieve the optimal state of gas and electrolyte in the H-type reaction cell, providing necessary conditions for real-time monitoring of infrared spectra; Real-time monitoring of S3 infrared spectrum; 1) During the electrochemical reaction, the infrared spectrometer monitors the vibration signals of the molecules on the working electrode surface through the reflection mode; the dynamic changes of the gas-liquid-solid three-phase interface are shown through the infrared spectra at different potentials; 2) By adjusting the reaction potential, the system can capture the generation, transformation and disappearance of active intermediates in the reaction; The output is real-time infrared spectroscopy data, which is used to analyze and understand the dynamic mechanism of the electrocatalytic reaction; S4 Data analysis and interpretation; 1) By analyzing the infrared spectra at different potentials and different times, the adsorption changes of organic matter at the three-phase interface during the electrocatalytic reaction can be obtained to achieve in-situ monitoring; 2) Analyze the real-time data collected in S3 to reveal the dynamic mechanism of the electrocatalytic reaction.

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