Electrocatalytic reaction device for electron paramagnetic resonance detection

Abstract

The invention provides an electro-catalytic reaction device for electron paramagnetic resonance detection, and relates to the technical field of electrochemistry. The electro-catalytic reaction device comprises an upper end cover, a cylindrical shell, a lower end cover and a pump, one end of the cylindrical shell is hermetically connected with the upper end cover, and the other end of the cylindrical shell is hermetically connected with the lower end cover to form an electro-catalysis reaction tank; the upper end cover comprises three orifices, a reference electrode is placed in the first orifice in a sealed manner, a counter electrode is placed in the second orifice in a sealed manner, and the third orifice is used as an electrolyte inflow port; the lower end cover comprises two orifices, one orifice is hermetically provided with a working electrode, and the other orifice is used as an electrolyte outlet; and the pump is used for pumping the electrolyte from the electrolyte inlet and pumping the electrolyte from the electrolyte outlet. The device is simple in structure, gas can be effectively prevented from being accumulated in the electrolytic bath, and the accuracy of electron paramagnetic resonance detection is improved.

Description

Technical Field

[0001] The invention relates to the technical field of electrochemistry, and in particular to an electrocatalytic reaction device for electron paramagnetic resonance detection. Background Art

[0002] Electrochemical energy storage and material conversion are expected to provide effective solutions to the problem of regional distribution and uneven output of renewable clean energy (hydropower, wind power, solar energy, geothermal energy, etc.), and electrocatalysis is a key reaction process. However, there are problems in the study of electrocatalysis, such as the influence of the external field environment on the electronic state of the catalyst surface interface and the unclear regulation mechanism. Therefore, it is urgent to develop in-situ, dynamic, and working conditions research methods and research equipment, establish the precise identification and analysis methodology of in-situ characterization signals, and understand the directional participation of electronic interfaces in reactions and material and energy exchange processes from the perspective of molecules and atoms.

[0003] As the core process of the electrocatalytic system, effectively tracking the interfacial electron transfer process is a key means to analyze the catalytic mechanism and its structure-activity relationship. Electron paramagnetic resonance is a highly sensitive magnetic resonance fast response technology originating from the magnetic moment of a single electron. It is the only research method that can directly track unpaired electrons. However, the gases produced during the electrocatalytic process (such as hydrogen and oxygen evolution) will affect the microwave absorption efficiency (i.e., quality factor) in the instrument test cavity, thereby affecting the sample test signal. In addition, the ineffective absorption of microwaves by polar solvents will further weaken the electron paramagnetic resonance signal intensity of the research sample.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The first object of the present invention is to provide an electrocatalytic reaction device for electron paramagnetic resonance detection to solve the above-mentioned problems.

[0006] The second object of the present invention is to provide an application of the above-mentioned electrocatalytic reaction device in sample electron paramagnetic resonance detection.

[0007] The third object of the present invention is to provide a method for electron paramagnetic resonance detection.

[0008] A fourth object of the present invention is to provide an electron paramagnetic resonance spectrometer.

[0009] In a first aspect, the present invention provides an electrocatalytic reaction device for electron paramagnetic resonance detection, comprising: an upper end cover, a cylindrical shell, a lower end cover and a pump; One end of the cylindrical shell is sealed and connected to the upper end cover, and the other end is sealed and connected to the lower end cover, forming an electrocatalytic reaction tank; The upper end cover comprises three openings, wherein the first opening is sealed with a reference electrode, the second opening is sealed with a counter electrode, and the third opening is used as an electrolyte inlet; The lower end cover comprises two openings, one of which is sealed with a working electrode, and the other is used as an electrolyte outlet; The pump is used to pump the electrolyte into the electrolyte inlet and pump it out from the electrolyte outlet.

[0010] As a further technical solution, the material of the cylindrical shell includes quartz glass or polyvinyl alcohol.

[0011] As a further technical solution, the reference electrode is sealed and connected to the orifice where it is placed by means of polytetrafluoroethylene tape; The counter electrode is sealed and connected to the orifice where it is placed by means of polytetrafluoroethylene tape; The working electrode is sealed and connected to the orifice where it is placed by polytetrafluoroethylene tape.

[0012] As a further technical solution, one end of the reference electrode, the counter electrode and the working electrode is inserted deep into the electrocatalytic reaction tank; The reference electrode, the counter electrode and the working electrode are not in contact with each other.

[0013] As a further technical solution, the cylindrical shell is cylindrical in shape; The inner diameter of the cylindrical shell is 1.5-4.5 mm.

[0014] In a second aspect, the present invention provides the use of the above-mentioned electrocatalytic reaction device in electron paramagnetic resonance detection of samples or electrolytes.

[0015] As a further technical solution, the sample includes an alloy, a metal oxide, a sulfide or a carbon material.

[0016] In a third aspect, the present invention provides a method for electron paramagnetic resonance detection, comprising the following steps: The sample to be tested is mounted on the working electrode in the electrocatalytic reaction device, and then the pump is turned on, and the electrode voltage or current is adjusted to allow the sample to undergo an electrochemical reaction, and the electron paramagnetic resonance signal of the sample to be tested or the electrolyte under the catalytic action of the sample to be tested is detected.

[0017] As a further technical solution, an electron paramagnetic resonance spectrometer is used to detect the electron paramagnetic resonance signal of the sample to be tested or the electrolyte.

[0018] In a fourth aspect, the present invention provides an electron paramagnetic resonance spectrometer, wherein the electrocatalytic reaction device is arranged in a resonant cavity of the electron paramagnetic resonance spectrometer.

[0019] Compared with the prior art, the electrocatalytic reaction device provided by the present invention has the following beneficial effects: (1) Modular design to simplify operation and installation: The device adopts modular design, which makes operation and installation easier and improves the usability of the device.

[0020] (2) The solvent content in the in-situ cell is low, which improves the signal-to-noise ratio: The diameter of the reaction pool of the device can be made smaller, so that the content of polar solvent in the pool is less, which is beneficial to the characteristic signal performance of the research object, thereby improving the signal-to-noise ratio and making the experimental results more accurate and reliable.

[0021] (3) The design of flowing electrolyte (electrolyte inlet + electrolyte outlet + pump) ensures that the gas is discharged in time and guarantees the accuracy of the test results: The design of the flowing electrolyte system ensures that the gas generated during the electrocatalytic process can be discharged in time, keeping the quality factor of the test chamber constant, thereby ensuring that the test results are not interfered by factors other than voltage / current, and improving the accuracy of the test results.

[0022] (4) The electrolyte design of the flow system achieves multifunctionality: The design of the mobile electrolyte system allows the effective catalytic components in the electrolyte, such as oxygen and carbon dioxide, to be changed during the in-situ test, thus realizing the multifunctionality of the mobile system. At the same time, the dynamic evolution of various small molecules in the electrolyte under electrocatalysis can also be monitored. This helps to simulate and study a variety of electrocatalytic reactions under different conditions and provides more flexible experimental conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 This is a schematic diagram of a device according to Embodiment 1 of the present invention; Figure 2 The size of the upper end cover of the device in Example 1 of the present invention; Figure 3 The dimensions of the lower end cover of the device in Example 1 of the present invention; Figure 4 The dimensions of the cylindrical shell of the device in Example 1 of the present invention; Figure 5 Comparison of the electron paramagnetic resonance signal of cobalt metal oxide before and after applying voltage.

[0025] Icon: 1-upper end cover; 11-counter electrode; 12-reference electrode; 13-electrolyte inlet; 2-cylindrical shell; 3-lower end cover; 31-working electrode; 32-electrolyte outlet. DETAILED DESCRIPTION

[0026] The embodiments of the present invention will be described in detail below in conjunction with the embodiments and examples, but it will be appreciated by those skilled in the art that the following embodiments and examples are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified, proceed according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0027] In a first aspect, the present invention provides an electrocatalytic reaction device for electron paramagnetic resonance detection, comprising: an upper end cover, a cylindrical shell, a lower end cover and a pump; One end of the cylindrical shell is sealed and connected to the upper end cover, and the other end is sealed and connected to the lower end cover, forming an electrocatalytic reaction tank; The upper end cover comprises three openings, wherein the first opening is sealed with a reference electrode, the second opening is sealed with a counter electrode, and the third opening is used as an electrolyte inlet; The lower end cover comprises two openings, one of which is sealed with a working electrode, and the other is used as an electrolyte outlet; The pump is used to pump the electrolyte into the electrolyte inlet and pump it out from the electrolyte outlet.

[0028] The electrocatalytic reaction device for electron paramagnetic resonance detection provided by the present invention can eliminate various gases generated in the electrocatalytic process in real time through the ingenious design of the device structure and the liquid flow system, ensuring that the quality factor in the reaction tank remains constant, thereby ensuring that the signal strength of the test sample is not interfered by factors other than voltage. In addition, the design of the liquid flow system can also effectively regulate the electrode interface microenvironment (for example, by introducing different gases, or changing the pH value of the electrolyte, etc.), and capture catalyst signals under different working conditions. The device and test method are easy to operate and have a wide range of applications.

[0029] In some optional embodiments, the material of the cylindrical shell includes quartz glass or polyvinyl alcohol.

[0030] The cylindrical shell made of the above material can maximize the simple harmonic resonance of the test sample in the device and enhance the sensitivity of the test.

[0031] In some optional embodiments, the reference electrode is sealed and connected to the orifice where it is placed by polytetrafluoroethylene tape; The counter electrode is sealed and connected to the orifice where it is placed by means of polytetrafluoroethylene tape; The working electrode is sealed and connected to the orifice where it is placed by polytetrafluoroethylene tape.

[0032] In some optional embodiments, one end of the reference electrode, the counter electrode and the working electrode is inserted deep into the electrocatalytic reaction tank; The reference electrode, the counter electrode and the working electrode are not in contact with each other.

[0033] In some optional embodiments, the cylindrical shell is cylindrical in shape; The inner diameter of the cylindrical shell may be, for example, but not limited to, 1.5 mm, 2.5 mm, 3.5 mm or 4.5 mm.

[0034] In some optional embodiments, the pump is communicated with the electrolyte inlet.

[0035] In some optional embodiments, the pump is also used to control the feed amount of the electrolyte to ensure the precise flow of the electrolyte during the electrocatalytic experiment.

[0036] The above technical features constitute the design of the entire device of the present invention, and play an important role in in-situ electrocatalysis, ensuring the efficient and reliable operation of the technical solution.

[0037] In a second aspect, the present invention provides the use of the above-mentioned electrocatalytic reaction device in electron paramagnetic resonance detection of samples or electrolytes.

[0038] The electrocatalytic reaction device provided by the present invention can effectively improve the accuracy of electron paramagnetic resonance detection by adjusting the electrode voltage to allow the sample to undergo an electrochemical reaction while avoiding gas accumulation in the electrolytic cell.

[0039] In some optional embodiments, the sample includes but is not limited to alloys, metal oxides, sulfides or carbon materials.

[0040] In some optional embodiments, the metal oxide includes but is not limited to cobalt oxide.

[0041] In a third aspect, the present invention provides a method for electron paramagnetic resonance detection, comprising the following steps: The sample to be tested is mounted on the working electrode in the electrocatalytic reaction device, and then the pump is turned on to pump the electrolyte in from the electrolyte inlet and out from the electrolyte outlet, and then the electrode voltage or current is adjusted to allow the sample to undergo an electrochemical reaction, and the electron paramagnetic resonance signal of the sample to be tested or the electrolyte under the catalytic action of the sample to be tested is detected.

[0042] The method is simple to operate, can effectively avoid gas accumulation in the electrolytic cell, and improve the accuracy of electron paramagnetic resonance detection.

[0043] In some optional embodiments, an electron paramagnetic resonance spectrometer is used to detect the electron paramagnetic resonance signal of the sample to be tested or the electrolyte.

[0044] In a fourth aspect, the present invention provides an electron paramagnetic resonance spectrometer, wherein the electrocatalytic reaction device is arranged in a resonant cavity of the electron paramagnetic resonance spectrometer.

[0045] The electron paramagnetic resonance spectrometer is used to detect the electron paramagnetic resonance signal of the sample.

[0046] The present invention is further described below by means of specific examples. However, it should be understood that these examples are only used for more detailed description and should not be construed as limiting the present invention in any form. Example 1

[0047] An electrocatalytic reaction device for electron paramagnetic resonance detection, having a structure as follows Figure 1 As shown, the size is Figure 2-Figure 4 (dimensions in the figure are in mm) as shown, comprising: an upper end cover 1, a cylindrical shell 2, a lower end cover 3 and a pump; One end of the cylindrical shell 2 is sealed with the upper end cover 1, and the other end is sealed with the lower end cover 3 to form an electrocatalytic reaction tank; the material of the cylindrical shell 2 is quartz glass; The upper end cover 1 includes three openings, wherein the first opening is sealed with a reference electrode 12, the second opening is sealed with a counter electrode 11, and the third opening is used as an electrolyte inlet 13; The lower end cover 3 includes two openings, one of which is sealed to house a working electrode 31, and the other opening is used as an electrolyte outlet 32; The pump is in communication with the electrolyte inlet 13 and is used to pump the electrolyte into the electrolyte inlet 13 and out of the electrolyte outlet 32 ​​. Test Example 1

[0048] The electrocatalytic reaction device provided in Example 1 was used to study the valence change of cobalt metal oxide: The sample to be tested is mounted on the working electrode 31 in the electrocatalytic reaction device, and then the pump is turned on to pump the electrolyte from the electrolyte inlet 13, and then the electrode voltage is adjusted to test the valence change of the cobalt metal ion at different potentials, and the electron paramagnetic resonance signal of the sample to be tested is detected. The results are as follows Figure 5 shown.

[0049] Figure 5It shows that at different potentials, the cobalt ions in Co metal oxides undergo valence changes through the electrochemical catalytic process. Under high potential conditions, the +2-valent cobalt ions are oxidized to +3-valent states, and this change is clearly shown by the electron paramagnetic resonance spectrum. It is worth noting that there are unpaired electrons in the +2-valent cobalt ions, while in the +3 cobalt ions, the electron paramagnetic resonance signal of cobalt disappears because an electron is lost in the oxidation process, resulting in the disappearance of unpaired electrons in the orbit.

[0050] This experimental result verifies the feasibility of the in-situ device we developed.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electrocatalytic reaction device for electron paramagnetic resonance detection, characterized in that: include: An upper end cover, a cylindrical casing, a lower end cover and a pump; One end of the cylindrical shell is sealed and connected to the upper end cover, and the other end is sealed and connected to the lower end cover, forming an electrocatalytic reaction tank; The upper end cover comprises three openings, wherein the first opening is sealed with a reference electrode, the second opening is sealed with a counter electrode, and the third opening is used as an electrolyte inlet; The lower end cover comprises two openings, one of which is sealed with a working electrode, and the other is used as an electrolyte outlet; The pump is used to pump the electrolyte into the electrolyte inlet and pump it out from the electrolyte outlet.

2. The electrocatalytic reaction device according to claim 1, characterized in that: The material of the cylindrical shell includes quartz glass or polyvinyl alcohol.

3. The electrocatalytic reaction device according to claim 1, characterized in that: The reference electrode is sealed and connected to the orifice where it is placed by means of polytetrafluoroethylene tape; The counter electrode is sealed and connected to the orifice where it is placed by means of polytetrafluoroethylene tape; The working electrode is sealed and connected to the orifice where it is placed by polytetrafluoroethylene tape.

4. The electrocatalytic reaction device according to claim 1, characterized in that: One end of the reference electrode, the counter electrode and the working electrode is inserted into the electrocatalytic reaction tank; The reference electrode, the counter electrode and the working electrode are not in contact with each other.

5. The electrocatalytic reaction device according to claim 1, characterized in that: The cylindrical shell is cylindrical in shape; The inner diameter of the cylindrical shell is 1.5-4.5 mm.

6. Use of the electrocatalytic reaction device according to any one of claims 1 to 5 in electron paramagnetic resonance detection of samples or electrolytes.

7. The use according to claim 6, characterized in that: The sample includes an alloy, a metal oxide, a sulfide or a carbon material.

8. A method for electron paramagnetic resonance detection, characterized in that: The following steps are involved: The sample to be tested is mounted on the working electrode in the electrocatalytic reaction device described in any one of claims 1 to 5, and then the pump is turned on, and the electrode voltage or current is adjusted to allow the sample to undergo an electrochemical reaction, and the electron paramagnetic resonance signal of the sample to be tested or the electrolyte under the catalytic action of the sample to be tested is detected.

9. The method according to claim 8, characterized in that An electron paramagnetic resonance spectrometer is used to detect the electron paramagnetic resonance signal of the sample or electrolyte to be tested.

10. An electron paramagnetic resonance spectrometer, characterized in that: The resonant cavity of the electron paramagnetic resonance spectrometer is provided with the electrocatalytic reaction device according to any one of claims 1 to 5.

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