Electrochemical in-situ mass spectrometry detection device

Abstract

The invention relates to the technical field of electrochemical in-situ characterization, in particular to an electrochemical in-situ mass spectrometry detection device. Comprising a primary ionization and precipitation system, a secondary reagent auxiliary ionization system, an adjustable pressure air source, a fine-aperture tee joint, an electrochemical cell and a mass spectrometer, three ports of the fine-aperture tee joint are connected with the adjustable pressure air source, the electrochemical cell and a spraying pipeline respectively, and the primary ionization and precipitation system is arranged at the lower end of the spraying pipeline. The ionizer is used for ionizing gas and a sample in the spraying pipeline; the secondary reagent-assisted ionization system is used for performing reagent-assisted secondary ionization on primary ions and neutral molecule plumes; and the generated ions enter a mass spectrometer for analysis. Effective carrying of products in the electrochemical reaction tank is achieved through high-speed airflow generated by the pressure-adjustable gas source, primary ionization and precipitation of the products are achieved through the induction electrode under the radio frequency voltage, secondary ionization is achieved in combination with the auxiliary gas and the auxiliary light source, and the ionization efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of in-situ electrochemical characterization, and particularly to an in-situ electrochemical mass spectrometry detection device. Background Art

[0002] The electrochemical mass spectrometry method is an analytical instrument integrating electrochemical technology and mass spectrometry technology. It has the advantages of fast detection speed, high sensitivity, high accuracy, high efficiency, etc. It can perform real-time in-situ analysis, quantitative analysis, qualitative analysis, etc. on volatile reactants, intermediates, reaction products, and final products in electrochemical reactions. It has broad application prospects in the fields of lithium battery electrolyte development, battery charging and discharging, water electrolysis for hydrogen evolution, CO 2 reduction, small molecule oxidation, electrocatalytic ammonia synthesis, electrochemical corrosion, etc. At present, the detection method for gas-phase products in the electrochemical process is relatively mature, and the in-situ detection of liquid-phase products has always been a difficult problem.

[0003] Through the retrieval of patents and papers, the patents related to electrochemistry, in-situ, and mass spectrometry retrieved are as follows: 1. A device for in-situ monitoring of electrochemical reactions applied and disclosed by Wuhan University on January 17, 2023. This in-situ monitoring device uses an external electrostatic field that is not in direct contact with the solution in the reactor of the electrochemical reaction, thereby realizing the ionization of the solution at the tip of the reactor, thus avoiding the problem of a large difference from the ordinary electrochemical reaction environment in the laboratory caused by applying a high-voltage in the reactor in the related technology. However, this invention does not clearly disclose the method for extracting liquid-phase products. 2. An electrochemical-mass spectrometry coupling device and its use method applied and disclosed by Harbin Institute of Technology (Weihai) on October 19, 2018, including a mass spectrometer and an electrochemical reaction device. The electrochemical reaction platform is designed as a carrier with a sharp corner, and one of the sharp corners of the carrier is set as the sample corner; the electrochemical electrode combination controls the voltage for the electrochemical reaction and the ionization spray voltage of the sample solution through a power supply workstation, so that the sample solution to be measured at the sample corner undergoes an electrochemical reaction and generates electrospray ionization, and the ions of the electrospray enter the mass spectrometry inlet. The main problem of this device is that the combination of the electrochemical reaction platform and the ionization source will affect the electrochemical reaction environment, and the results do not conform to the actual application. Summary of the Invention

[0004] Aiming at the above problems, the purpose of the present invention is to provide an in-situ electrochemical mass spectrometry detection device to achieve the in-situ detection of compounds in the electrochemical process.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] The present invention provides an in-situ electrochemical mass spectrometry detection device, which includes a primary ionization and precipitation system, a secondary reagent-assisted ionization system, an adjustable pressure gas source, a fine-aperture three-way joint, an electrochemical cell and a mass spectrometer. The adjustable pressure gas source is connected to the upper port of the fine-aperture three-way joint through a gas source connection pipeline. The side port of the fine-aperture three-way joint is connected to the electrochemical cell through an electroanalyte introduction pipeline. The lower port of the fine-aperture three-way joint is connected to the upper end of a spray pipeline. The primary ionization and precipitation system is arranged at the lower end of the spray pipeline. The adjustable pressure gas source generates an air flow that passes through the fine-aperture three-way joint. The liquid sample in the electrochemical cell enters the fine-aperture three-way joint through the analyte introduction pipeline and is carried by the gas into the spray pipeline. The primary ionization and precipitation system is used to ionize the gas and sample in the spray pipeline, so as to generate a primary ion and a neutral molecule plume in the spray pipeline. The secondary reagent-assisted ionization system and the mass spectrometer are arranged in sequence along the spray direction of the spray pipeline. The secondary reagent-assisted ionization system is used to perform reagent-assisted secondary ionization on the primary ion and the neutral molecule plume. The finally generated ions enter the mass spectrometer for analysis under the action of voltage and air flow.

[0007] The primary ionization and precipitation system includes a radio frequency electrode and a radio frequency power supply. The radio frequency electrode is in the shape of a rectangular flat plate and is placed at the lower end of the spray pipeline. The radio frequency electrode is connected to the radio frequency power supply through a wire. A radio frequency voltage is applied to the radio frequency electrode through the radio frequency power supply. The gas and sample in the spray pipeline generate a primary ion and a neutral molecule plume under the action of the radio frequency electric field of the radio frequency electrode.

[0008] The secondary reagent-assisted ionization system includes an auxiliary light source and an auxiliary gas. The auxiliary gas and the auxiliary light source are respectively placed on both sides of the primary ion and the neutral molecule plume, and can perform reagent-assisted secondary ionization on the un-ionized neutral molecule plume.

[0009] The auxiliary light source is an ultraviolet light source, an infrared light source, a discharge light source or a laser light source.

[0010] The auxiliary gas is acetone, toluene or methanol.

[0011] The inner diameter of the fine-aperture three-way joint is smaller than the inner diameters of the gas source connection pipeline, the analyte introduction pipeline and the spray pipeline.

[0012] The spray pipeline is made of a non-metallic material, and the spray pipeline is placed opposite to and at a certain interval from the sampling port of the mass spectrometer.

[0013] The adjustable pressure gas source is a compressed steel cylinder or a gas generator; the gas provided by the adjustable pressure gas source is an inert gas.

[0014] The gas source connection pipeline, the fine-aperture three-way joint and the analyte introduction pipeline are made of metal or non-metallic materials.

[0015] The mass spectrometer is a quadrupole mass spectrometer, a time-of-flight mass spectrometer, a magnetic mass spectrometer, an ion trap mass spectrometer, an orbitrap mass spectrometer or a tandem mass spectrometer.

[0016] The advantages and beneficial effects of the present invention are as follows: An in-situ electrochemical mass spectrometry detection device provided by the present invention, through reasonable design, utilizes the Venturi effect to generate a high-speed gas flow through an adjustable pressure gas source to effectively carry the products in the electrochemical reaction cell, and uses an induction electrode under a radio frequency voltage to achieve primary ionization and precipitation of the products. Then, combined with auxiliary gas and an auxiliary light source, secondary desorption and secondary ionization are realized, improving the ionization efficiency. This design structure can achieve in-situ and efficient detection of electrochemical reactions without affecting the environment in the reaction cell, and has good application prospects in the in-situ electrochemical liquid-phase characterization. Description of the Drawings

[0017] The drawings further illustrate the present invention, but the content in the drawings does not constitute any limitation to the present invention.

[0018] Figure 1 It is a schematic structural diagram of an in-situ electrochemical mass spectrometry detection device of the present invention.

[0019] In the figure: 1 - gas source connection pipeline, 2 - adjustable pressure gas source, 3 - radio frequency power supply, 4 - primary ion and neutral molecule plume, 5 - auxiliary light source, 6 - mass spectrometer, 7 - radio frequency electrode, 8 - spray pipeline, 9 - fine-aperture three-way joint, 10 - electroanalyte introduction pipeline, 11 - electrochemical cell, 12 - electrochemical reaction electrode, 13 - auxiliary gas. Detailed Embodiments

[0020] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0021] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The description of at least one exemplary embodiment below is actually only illustrative and in no way constitutes a limitation to the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0022] Note that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, unless the context clearly dictates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprises" and / or "comprising" are used in this specification, they specify the presence of the stated features, steps, operations, devices, components, and / or combinations thereof.

[0023] Unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions, and values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed herein, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not require further discussion in subsequent drawings.

[0024] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom", etc. are generally based on the orientation or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Without contrary instructions, these orientation words do not indicate or imply that the devices or elements referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the protection scope of the present invention. The orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0025] As Figure 1As shown in the figure, the present invention provides an in-situ electrochemical mass spectrometry detection device, which includes a primary ionization and precipitation system, a secondary reagent-assisted ionization system, an adjustable pressure gas source 2, a fine-aperture three-way joint 9, an electrochemical cell 11 and a mass spectrometer 6. Among them, the adjustable pressure gas source 2 is connected to the upper port of the fine-aperture three-way joint 9 through a gas source connection pipeline 1. The side port of the fine-aperture three-way joint 9 is connected to the electrochemical cell 11 through an electroanalyte introduction pipeline 10. The lower port of the fine-aperture three-way joint 9 is connected to the upper end of a spray pipeline 8. The primary ionization and precipitation system is arranged at the lower end of the spray pipeline 8. The adjustable pressure gas source 2 generates an air flow that passes through the fine-aperture three-way joint 9, and the liquid sample in the electrochemical cell 11 enters the fine-aperture three-way joint 9 through the analyte introduction pipeline 10 and is carried by the gas into the spray pipeline 8. The primary ionization and precipitation system is used to ionize the gas and sample in the spray pipeline 8, so as to generate a primary ion and neutral molecule plume 4 in the spray pipeline 8. The secondary reagent-assisted ionization system and the mass spectrometer 6 are arranged in sequence along the spray direction of the spray pipeline 8. The secondary reagent-assisted ionization system is used to perform reagent-assisted secondary ionization on the primary ion and neutral molecule plume 4. The finally generated ions enter the mass spectrometer 6 for analysis under the action of voltage and air flow.

[0026] In an embodiment of the present invention, the primary ionization and precipitation system includes a radio frequency electrode 7 and a radio frequency power supply 3. Among them, the radio frequency electrode 7 is in the shape of a rectangular flat plate and is placed at the lower end of the spray pipeline 8. The radio frequency electrode 7 is connected to the radio frequency power supply 3 through a wire. By applying a radio frequency voltage on the radio frequency electrode 7 through the radio frequency power supply 3, the gas and sample in the spray pipeline 8 generate a primary ion and neutral molecule plume 4 under the action of the radio frequency electric field of the radio frequency electrode 7.

[0027] In an embodiment of the present invention, the secondary reagent-assisted ionization system includes an auxiliary light source 5 and an auxiliary gas 13. The auxiliary gas 13 and the auxiliary light source 5 are respectively placed on both sides of the primary ion and neutral molecule plume 4, and can perform reagent-assisted secondary ionization on the un-ionized neutral molecule plume.

[0028] Specifically, the auxiliary light source 5 is an ultraviolet light source, an infrared light source, a discharge light source or a laser light source. The ultraviolet light source can play a role in ionizing the sample or reagent, and the infrared light source can play a role in thermal desorption. The auxiliary gas 13 is an organic solvent such as acetone, toluene or methanol.

[0029] Furthermore, the inner diameter of the fine-aperture three-way joint 9 is smaller than the inner diameters of the gas source connection pipeline 1, the analyte introduction pipeline 10 and the spray pipeline 8. The spray pipeline 8 is made of a non-metallic material such as PEEK, tetrafluoroethylene, quartz, etc.; the spray pipeline 8 is placed opposite to and at a certain interval from the sampling port of the mass spectrometer 6.

[0030] Specifically, the adjustable pressure gas source 2 is a compressed gas cylinder or a gas generator; the gas provided by the adjustable pressure gas source 2 is an inert gas such as nitrogen, helium or argon. Preferably, the adjustable pressure gas source 2 is a compressed gas cylinder; the gas is high-purity helium. The gas source connection pipeline 1, the fine-aperture three-way 9 and the analyte introduction pipeline 10 are made of metal materials such as stainless steel, copper, passivated stainless steel, etc.; or non-metal materials such as PEEK, tetrafluoroethylene, quartz, etc. The mass spectrometer 6 is a quadrupole mass spectrometer, a time-of-flight mass spectrometer, a magnetic mass spectrometer, an ion trap mass spectrometer, an orbitrap mass spectrometer or various tandem mass spectrometers.

[0031] Preferably, the gas source connection pipeline 1 is made of metal material and can withstand higher gas pressure; the electro-analyte introduction pipeline 10 is made of PEEK material and can withstand the corrosion of the electrolyte; the spray pipeline 8 is made of quartz material with less residue; the fine-aperture three-way 9 is made of passivated stainless steel material with good corrosion resistance and airtightness. The auxiliary light source 5 is the combined action of an ultraviolet light source and an infrared light source. The ultraviolet light source selects a high-power gas discharge lamp with higher ionization efficiency, and the infrared light source selects a high-power infrared laser with higher pyrolysis and desolvation efficiency. The auxiliary gas 13 is selected as acetone, which has low toxicity and is easy to generate proton transfer reaction ionization. The mass spectrometer 6 is a tandem orbitrap mass spectrometer with higher resolution; it can also be a tandem time-of-flight mass spectrometer with higher analysis speed.

[0032] An in-situ electrochemical mass spectrometry detection device provided by the present invention has the following working principle:

[0033] During operation, an electrolyte and an electrochemistry reaction electrode 12 are placed in the electrochemistry cell 11, and the electrochemistry reaction electrode 12 is connected to an electrochemistry workstation; the adjustable pressure gas source 2 is adjusted to generate an air flow passing through the fine-aperture three-way 9; due to the increase in the flow rate of the air flow in the fine-aperture three-way 9, under the action of the Venturi effect, the liquid sample in the electrochemistry cell 11 will slowly enter the fine-aperture three-way 9 through the analyte introduction pipeline 10 and be carried by the gas into the spray pipeline 8; a radio frequency voltage is applied to the radio frequency electrode 7 through the radio frequency power supply 3; thus, the gas and the sample in the spray pipeline 8 are sprayed under the action of the radio frequency electric field of the radio frequency electrode 7 to form a primary ion and a neutral molecule plume 4. The neutral molecules in the primary ion and neutral molecule plume 4 are pyrolyzed under the action of the auxiliary light source 5, and at the same time, the auxiliary gas 13 is ionized to provide reaction reagent ions, and then secondary ionization occurs through chemical reaction ionization; finally, the generated primary and secondary ions enter the mass spectrometer 6 for analysis under the action of voltage and air flow, so as to realize the in-situ and efficient detection of the liquid-phase products during the electrochemistry reaction process. The present invention can realize the in-situ detection of the electrochemistry reaction without affecting the environment in the reaction cell, and has good application prospects in the in-situ electrochemical liquid-phase characterization.

[0034] The present invention uses a reasonable design to utilize the high-speed airflow generated by the Venturi effect through an adjustable pressure gas source to achieve effective carrying of the product in the electrochemical reaction cell, utilizes the induction electrode under the radio frequency voltage to achieve the primary ionization and precipitation of the product, and then combines the auxiliary gas and auxiliary light source to achieve secondary desorption and secondary ionization, thereby improving the ionization efficiency. This design structure can realize in-situ efficient detection of electrochemical reactions without affecting the environment in the reaction cell, and has a good application prospect in the in-situ characterization of electrochemical liquid phases.

[0035] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific embodiments of the present invention without creative work, and these equivalent variations or substitutions are all included in the scope defined by the claims of this application.

[0036] 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 in-situ electrochemical mass spectrometry detection device, characterized in that, it includes a primary ionization and precipitation system, a secondary reagent-assisted ionization system, an adjustable pressure gas source (2), a fine-aperture three-way joint (9), an electrochemical cell (11) and a mass spectrometer (6). The adjustable pressure gas source (2) is connected to the upper port of the fine-aperture three-way joint (9) through a gas source connection pipeline (1). The side port of the fine-aperture three-way joint (9) is connected to the electrochemical cell (11) through an electroanalyte introduction pipeline (10). The lower port of the fine-aperture three-way joint (9) is connected to the upper end of a spray pipeline (8). The primary ionization and precipitation system is arranged at the lower end of the spray pipeline (8). The adjustable pressure gas source (2) generates an air flow passing through the fine-aperture three-way joint (9), and the liquid sample in the electrochemical cell (11) enters the fine-aperture three-way joint (9) through the analyte introduction pipeline (10) and is carried by the gas into the spray pipeline (8). The primary ionization and precipitation system is used to ionize the gas and sample in the spray pipeline (8) to generate a primary ion and neutral molecule plume (4) in the spray pipeline (8). The secondary reagent-assisted ionization system and the mass spectrometer (6) are arranged in sequence along the spray direction of the spray pipeline (8). The secondary reagent-assisted ionization system is used to perform reagent-assisted secondary ionization on the primary ion and neutral molecule plume (4). The finally generated ions enter the mass spectrometer (6) for analysis under the action of voltage and air flow.

2. The in-situ electrochemical mass spectrometry detection device according to claim 1, characterized in that, the primary ionization and precipitation system includes a radio frequency electrode (7) and a radio frequency power supply (3). The radio frequency electrode (7) is in the shape of a rectangular flat plate and is placed at the lower end of the spray pipeline (8). The radio frequency electrode (7) is connected to the radio frequency power supply (3) through a wire. A radio frequency voltage is applied to the radio frequency electrode (7) through the radio frequency power supply (3), and the gas and sample in the spray pipeline (8) generate a primary ion and neutral molecule plume (4) under the action of the radio frequency electric field of the radio frequency electrode (7).

3. The in-situ electrochemical mass spectrometry detection device according to claim 1, characterized in that, the secondary reagent-assisted ionization system includes an auxiliary light source (5) and an auxiliary gas (13). The auxiliary gas (13) and the auxiliary light source (5) are respectively placed on both sides of the primary ion and neutral molecule plume (4) to perform reagent-assisted secondary ionization on the un-ionized neutral molecule plume.

4. The in-situ electrochemical mass spectrometry detection device according to claim 3, characterized in that, the auxiliary light source (5) is an ultraviolet light source, an infrared light source, a discharge light source or a laser light source.

5. The in-situ electrochemical mass spectrometry detection device according to claim 3, characterized in that, the auxiliary gas (13) is acetone, toluene or methanol.

6. The in-situ electrochemical mass spectrometry detection device according to claim 1, characterized in that, the inner diameter of the fine-aperture three-way joint (9) is smaller than the inner diameters of the gas source connection pipeline (1), the analyte introduction pipeline (10) and the spray pipeline (8).

7. The in-situ electrochemical mass spectrometry detection device according to claim 1, characterized in that, The spray pipeline (8) is made of non-metallic material, and the spray pipeline (8) is placed opposite to and spaced from the sampling port of the mass spectrometer (6).

8. The in-situ electrochemical mass spectrometry detection device according to claim 1, characterized in that the adjustable pressure gas source (2) is a compressed gas cylinder or a gas generator; the gas provided by the adjustable pressure gas source (2) is an inert gas.

9. The in-situ electrochemical mass spectrometry detection device according to claim 1, characterized in that the gas source connection pipeline (1), the fine-aperture tee (9) and the analyte introduction pipeline (10) are made of metal or non-metallic material.

10. The in-situ electrochemical mass spectrometry detection device according to claim 1, characterized in that the mass spectrometer (6) is a quadrupole mass spectrometer, a time-of-flight mass spectrometer, a magnetic mass spectrometer, an ion trap mass spectrometer, an orbitrap mass spectrometer or a tandem mass spectrometer.

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