CN118258870A - Sampling probe electrode and in-situ electrochemical microsampling detection system - Google Patents
Sampling probe electrode and in-situ electrochemical microsampling detection system Download PDFInfo
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Abstract
The invention discloses a sampling probe electrode and an in-situ electrochemical microsampling detection system, the sampling probe electrode comprises a sampling probe electrode body with a tip and a hollow channel, a plurality of mutually insulated metal electrode layers are coated outside the tip, a filling material which is selectively penetrated by gas is filled in the hollow channel, and the filling material comprises a polymer film and/or a metal-organic framework MOF material. The filling material for selectively penetrating the gas is filled in the sampling probe electrode, and the metal electrode layer is coated outside the tip of the probe, so that the adaptability can be improved, the gas sampling detection of multiple systems can be met, the gas can be selectively penetrated, and the detection requirement can be met; the in-situ electrochemical micro-sampling detection system comprises a vacuum electrode sampling module and a trace gas analysis module; the vacuum electrode sampling module comprises the sampling probe electrode; the system can be used for in-situ real-time product detection of various electrochemical catalytic systems, realizes coupling of electrochemical signals with product types and yields, has good stability of the whole system, is simple and convenient to operate, and can obtain stable and accurate test results on the premise of not affecting the performance of the electrochemical catalyst.
Description
Technical Field
The invention relates to a sampling probe electrode and an in-situ electrochemical microsampling detection system, and belongs to the technical field of electrochemical analysis.
Background
Electrochemical catalysis is a scientific field that explores how catalysts can be used to promote related reactions in electrochemical systems. The research fields related to electrochemical catalysis are very wide, and include energy conversion, environmental management, industrial production and other fields. For example, in the field of energy conversion, electrochemical catalysis can be used in reactions such as fuel cells, water electrolysis hydrogen production and the like, and the reaction efficiency and the purity of the product are improved. In the field of environmental control, electrochemical catalysis can be used for degrading organic pollutants, removing heavy metals and other reactions, and environmental purification is realized.
In most of the existing electrochemical catalytic systems, cognition on the generation process of intermediate and final products is very limited, and due to the limitation of the reaction mechanism of the system, various gas products are in pmol magnitude, and trace gas detection on the reaction process of the system cannot be performed in situ and in real time by the conventional characterization means. And the existing sampling electrode probe has fewer systems capable of detecting and can not be used for selectively conveying collected gas to a gas analysis module.
Therefore, the in-situ real-time electrochemical trace product sampling detection system capable of detecting more systems and delivering the gas generated by the electrochemical reaction to the gas separation module and suitable for researching the reaction mechanism of different catalysts of the electrochemical system and coupling the electrochemical signal with the electrochemical product is provided, and is a problem to be solved by those skilled in the art.
Disclosure of Invention
The first object of the present invention is to provide a sampling probe electrode, which is suitable for gas sampling detection of multiple systems, and can improve adaptability by filling a filling material selectively permeable to gas in the sampling probe electrode and coating a metal electrode layer outside the tip of the probe, and can also selectively permeable to gas to meet detection requirements.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
A sampling probe electrode comprising a sampling probe electrode body having a tip and a hollow channel, the tip being overcoated with a plurality of mutually insulated metal electrode layers, the hollow channel being internally filled with a filler material selectively permeable to gas, the filler material comprising a polymer membrane and/or a metal organic framework MOF material.
Preferably, the sampling probe electrode body is a glass capillary.
Preferably, the tip is any one of carbon nano tube, conductive rubber, conductive nano metal material and non-conductive material;
Wherein the conductive nano metal material comprises metal nano particles or metal nano wires; the non-conductive material comprises glass fibers.
Preferably, the metal electrode layer comprises an Au electrode layer and a Pt electrode layer.
An in-situ electrochemical micro-sampling detection system comprises a main controller, a vacuum electrode sampling module and a trace gas analysis module;
The vacuum electrode sampling module comprises an electrochemical sample stage, a potential controller, a first XYZ coordinate stage, a displacement controller and at least one sampling probe electrode according to any one of claims 1-5;
The electrochemical sample platform is used for placing an electrochemical test sample, and a reference electrode and an auxiliary electrode are arranged at the substrate;
the potential controller is connected with the metal electrode layer of the sampling probe electrode and the main controller and is used for controlling electrochemical parameters of each electrode in the electrochemical reaction system;
The electrochemical sample stage is arranged on the first XYZ coordinate stage, and the first XYZ coordinate stage is connected with the displacement controller and the main controller and is used for controlling the displacement of the electrochemical sample stage in the three-dimensional space to change the position of the sampling probe electrode in the electrochemical field;
The sampling probe electrode is used for applying an electrochemical signal provided by the potential controller to an electrochemical field in the electrochemical sample stage and can selectively permeate gas generated by electrochemical reaction;
The trace gas analysis module is connected with the main controller and the sampling probe electrode and is used for collecting the gas permeated by the sampling probe electrode and ionizing and detecting the permeated gas.
Preferably, the trace gas analysis module comprises a sample injection capillary, a high cyclotron ionization ion source, vacuum equipment, a mass analyzer and a detection module;
the sample injection capillary is connected with the hollow channel of the sampling probe electrode and the high cyclotron ionization ion source, and the high cyclotron ionization ion source is sequentially connected with the mass analyzer and the detection module and is connected with the vacuum equipment; the detection module is connected with the main controller;
Under the action of vacuum equipment, gas selectively penetrating through the sampling probe electrode enters the high cyclotron ionization ion source through the sample injection capillary, the high cyclotron ionization ion source ionizes the gas to form charged ion beams, the charged ion beams enter the mass analyzer to be separated into charged particles with different masses, and the detection module detects currents generated by the charged particles with different masses.
Preferably, the sampling probe electrodes are multiple and distributed in an array.
Preferably, the vacuum electrode sampling module further comprises a multichannel array sampler;
The multichannel array sample injector comprises a sleeve, a rotor arranged in the sleeve and a stepping motor used for driving the rotor to rotate in the sleeve; the sleeve is fixed on the second XYZ coordinate table, the second XYZ coordinate table and the stepping motor are connected with the displacement controller, and the displacement controller controls the rotation of an executing shaft of the stepping motor and the action of the second XYZ coordinate table;
The sleeve is provided with a plurality of threaded holes communicated with the inner cavity of the sleeve along a thread line, and a sampling probe electrode is connected with the threaded holes by using a connecting capillary; the rotor is provided with a middle channel, the periphery is provided with micropores communicated with the middle channel, and the sample injection capillary is connected with the middle channel of the rotor;
The stepping motor drives the rotor to do spiral motion in the sleeve, the second XYZ coordinate table drives the sleeve to move along Z direction, when the micro holes on the rotor correspond to the threaded holes on the sleeve, gas generated at a certain position in the electrochemical field is pumped to the high-convolution ionization ion source to realize ionization of the gas, and then the charged particles with different masses are separated by the mass analyzer and then the current generated by the charged particles with different masses is detected by the detection module.
Preferably, the charged ions separated in the high cyclotron ionization ion source are pulsed vertically into the mass analyzer.
Preferably, an electromagnet is arranged in the high cyclotron ionization ion source, and electrons emitted in the high cyclotron ionization ion source spirally move under the action of an electric field and a magnetic field; the gas is continuously introduced into the high cyclotron ionization ion source and ionized under the action of the vacuum equipment.
The invention realizes real-time correspondence of trace gas quantity, types and electrochemical information by detecting pmol and trace gases below at different positions in the electrochemical field in situ, can be used for exploring electrochemical reaction mechanisms, catalyst properties and the like of various systems, and provides important characterization support for exploring electrochemical system mechanisms (such as the field of electrocatalysis) capable of generating gas. The system has the advantages of high quantitative accuracy, rich probe integration, quick response time and convenient testing process, can be widely applied to the fields of universities, scientific research institutions, related enterprises and the like, and has wide commercial prospect.
Compared with the prior art, the invention has the beneficial effects that:
The invention initiates the technology of organic combination of electrochemical probes and trace gas analysis, and provides a powerful characterization tool for mechanism exploration of various electrochemical systems. The gas yield of the electrochemical system is pmol or lower, and the conventional gas analyzer cannot realize the test of the gas yield of the magnitude under the vacuum environment. The electrochemical probe can integrate different electrochemical systems and perform in-situ real-time detection through a trace gas analyzer.
The probe provided by the invention can realize multifunctional coupling of electrochemical multiple catalyst integration, electrochemical signal giving, electrochemical product selective collection and the like, and can test various catalytic systems and various catalytic products, thereby increasing the applicability of the device.
The multichannel array sample injection system is adopted, so that electrochemical changes generated in the whole electrochemical field can be analyzed in situ in real time, and generated trace gas corresponds to information such as applied voltage, voltage and the like in real time, thereby being convenient for analyzing microscopic interface changes in the electrochemical system.
The high-convolution ionization ion source is adopted, and the ionized electrons are in spiral motion through electromagnetic control, so that the residence time of the electrons in the ion vacuum cavity is prolonged, and the ionization probability of sample gas is further improved. Compared with the linear motion of electrons, the ionization rate of the sample gas in the electron spiral motion can be improved by more than 2 orders of magnitude.
The high-cyclotron ionization ion source and the mass analyzer are vertically connected (namely charged ions separated in the high-cyclotron ionization ion source vertically enter the mass analyzer in a pulse mode), and when the mass analyzer performs ion pulse type sample injection test, ions can be guaranteed to be located at the same position, and the accuracy and reliability of ion mass analysis are improved to more than 99.99%.
And capillary connection is adopted, sampling is carried out by utilizing the internal and external pressure difference of the system through a multichannel array sampler, and after trace gas is generated, the mass spectrum response time can reach millisecond level.
Drawings
FIG. 1 is a system block diagram of an analysis system provided by the present invention;
FIG. 2 is a schematic diagram of the operation of a high cyclotron ionization ion source;
FIG. 3 is a schematic view at the tip; the left side is a cross-sectional view, and the right side is a top view;
Fig. 4 is a schematic view of the structure of the sleeve (left) and the rotor (right).
Detailed Description
The invention is described in detail below with reference to the drawings and examples.
Example 1
Fig. 1 is a schematic structural diagram of a full-automatic electrochemical mass spectrometry system according to an embodiment of the present invention. As shown in fig. 1, the in situ electrochemical micro-product sampling detection system comprises:
And the vacuum electrode sampling module is used for: the device comprises a sampling probe electrode, an electrochemical sample stage, a first XYZ coordinate stage, a displacement controller, a potential controller and a main controller (computer).
Trace gas analysis module: comprises a sample injection capillary, a high cyclotron ionization ion source, vacuum equipment, a mass analyzer and a detection module.
The electrochemical sample stage is arranged on the first XYZ coordinate stage, and the first XYZ coordinate stage is connected with the displacement controller and the main controller and is used for controlling the displacement of the electrochemical sample stage in the three-dimensional space so as to change the position (in the three-dimensional space) of an electrochemical field in the electrochemical sample stage and a sampling probe electrode (the sampling probe electrode can be fixed by arranging the third XYZ coordinate stage in practical application). The sampling probe electrode, the potential controller and the main controller are sequentially connected.
The trace gas analysis module is connected with the hollow channel of the sampling probe electrode through a sample injection capillary, and the sample injection capillary can be preferably a quartz capillary. The sample injection capillary is also connected with a high cyclotron ionization ion source, and the high cyclotron ionization ion source is sequentially connected with the mass analyzer and the detection module and is connected with vacuum equipment; the detection module is connected with the main controller.
Under the action of vacuum equipment, gas selectively penetrating through the sampling probe electrode enters the high cyclotron ionization ion source through the sample injection capillary, the high cyclotron ionization ion source ionizes the gas to form charged ion beams, the charged ion beams enter the mass analyzer to be separated into charged particles with different masses, and the detection module detects currents generated by the charged particles with different masses.
And the sampling probe electrode is wrapped by a plurality of layers of metal electrodes, a selective membrane is added in the sampling probe electrode, an electrochemical signal provided by a potential controller is applied to an electrochemical field in an electrochemical sample stage, and gas or volatile products in the electrochemical field are collected and then are transmitted to a high cyclotron ionization ion source through a quartz capillary tube.
Referring to fig. 1-2, the high cyclotron ionization ion source and the mass analyzer are both disposed within a vacuum metal chamber; the high cyclotron ionization ion source is connected with the sampling probe electrode and the mass analyzer and comprises electromagnetic control, an ion accelerating electrode, an electron accelerating electric field, an electron emission filament and an electromagnet; the electromagnetic control is used for adjusting the intensity of the magnetic field, electrons emitted by the electron emission filament are subjected to the interaction of an electric field and the magnetic field in the ionization chamber to perform spiral advance, the sample enters the ionization chamber and then is vertical to the direction of the electrons, compared with the linear advance, the electrons emitted by the electron emission filament which perform spiral advance have long residence time in the cavity, the number of the electrons distributed in the space is large, and the ionization rate of the sample can be improved by more than 2 orders of magnitude.
The mass analyzer adopts a flight time or a four-stage rod, the mass analyzer is connected with the high cyclotron ionization ion source through a slit of the cavity, charged ions generated by the high cyclotron ionization ion source are driven to vertically enter the mass analyzer through a control pulse signal, the ions vertically enter the mass analyzer relatively to horizontally, the positions of the ions entering the mass analyzer are guaranteed to be the same, and the resolution accuracy of the mass analyzer to the ions can be improved.
The detection module is provided with a gain-free ion detector and a gain-free ion detector, so that the gain-free ion detector with good conventional detection use stability can be started when detecting more trace gas. Preferably, the gain-free ion detector in the detection module of the device adopts a Faraday cup, and the gain-free ion detector adopts an electron multiplier.
The inner diameter of the quartz capillary is preferably 3 μm or 5. Mu.m. The quartz capillary junction interface is preferably 1/16 inch. The microporous quartz capillary is connected with different devices, and is preferably sealed by adopting 1/16 screw and polyimide compression ring matching; when in sealing, the microporous quartz capillary tube is required to be ensured not to be drawn through the adjusting screw, and air and high-purity Ar are used for detecting air tightness in a matching way.
The sample injection system can control a single sampling probe electrode to run in an electrochemical field by an XYZ console so as to test gas production at different positions; the sample injection can also be controlled by a multichannel array sample injection system, wherein the multichannel array sample injection system is made of peek material or stainless steel and consists of a sleeve, a rotor and a stepping motor. The sleeve is fixed on the second XYZ coordinate table, and the second XYZ coordinate table and the stepping motor are connected with the displacement controller, and the displacement controller controls the rotation of the executing shaft of the stepping motor and the action of the second XYZ coordinate table.
As shown in fig. 4, the surface of the sleeve is provided with a plurality of threaded holes which are uniformly distributed according to the thread line and are communicated with the inner cavity of the sleeve, and a connecting capillary (microporous quartz capillary) is used for respectively connecting the sampling probe electrode with the threaded holes on the sleeve; the rotor is provided with a middle channel, the periphery is provided with micropores communicated with the middle channel, and the sample injection capillary is connected with the middle channel of the rotor. The rotor spirally moves in the sleeve under the action of the stepping motor, meanwhile, the sleeve is driven to uniformly descend along the Z-axis direction through the second XYZ coordinate table, at the moment, the rotor spirally ascends relative to the sleeve, and the sampling capillary is also used for connecting the high cyclotron ionization ion source with the rotor. When the micropores on the rotor correspond to the threaded holes on the sleeve, a passage is formed, and gas generated at a certain position in the electrochemical field is pumped into the high-convolution ionization ion source under the action of vacuum equipment to ionize the gas, and then the charged particles with different masses are separated by the mass analyzer and then the current generated by the charged particles with different masses is detected by the detection module in the detection module.
The structure of the in-situ electrochemical micro-product sampling detection system provided by the invention is described above, and the working mode of the system is described below.
Taking the electrochemical signal and product analysis coupling test analysis of the product in the electrochemical catalysis process of the copper catalyst as an example: before testing, the trace gas analysis module is started and calibrated first. And before the equipment is started, the vacuum chamber is baked at high temperature, so that various magazines adsorbed in the vacuum chamber volatilize, and a high-vacuum environment is conveniently created. Starting the vacuum equipment after baking, wherein the specific process is to start the pre-pump and provide an operating environment of 10 -2 mbar for the molecular pump; starting a molecular pump, starting an electron emission filament in the high-cyclotron ionization ion source when the vacuum chamber is stabilized to a vacuum degree of below 10 -8 mbar, introducing high-purity Ar through a quartz capillary, and recording mass40 ion current intensity; and opening electromagnetic control and adjusting the magnetic field intensity, and fixing corresponding parameters of the electromagnetic control after the mass40 ion current intensity is improved by 2 orders of magnitude.
Subsequently, a sampling probe electrode is fabricated, either using a rigid glass capillary or a flexible material, such as carbon nanotubes, conductive rubber, etc., is also used for the tip probe. These materials are flexible, can accommodate sample surfaces of different shapes, and provide some electrical conductivity.
The middle of the sampling probe electrode is preferably a hollow capillary tube for collecting gas and volatile products generated by the reaction;
The PTFE membrane is preferably filled in the sampling probe electrode to prevent water vapor molecules from passing through and ensure that the product gas is normally collected. Various polymer films can be used in the interior, and the polymer films with special pore structures or functional groups can realize selective permeation of specific gases; metal organic frameworks MOFs are a class of crystalline structures composed of metal ions and organic ligands with a regulatable pore structure that can be used to selectively permeate specific gases.
The outside of the tip of the sampling probe electrode is an atmospheric pressure environment, the inside is a vacuum environment, and when the tip is close enough to the surface of the substrate, the generated gas and volatile products can be rapidly collected. The pressure difference between the inside and the outside of the membrane can realize the complete collection of the product; when the generated gas and volatile product amount are small, the size of the quartz capillary between the sampling probe electrode and the high cyclotron ionization ion source or the filling material in the capillary can be properly reduced, so that the collection of trace products is realized.
Referring to fig. 3, the surface of the tip of the sampling probe electrode is preferably coated with Au and Pt metals. The sampling probe electrode tip can be made of various electrode materials, and the materials have excellent conductivity and chemical stability and are suitable for researching a plurality of electrochemical reactions. The carbon nanotubes have unique electrochemical properties, high conductivity and excellent chemical stability. The tips of the carbon nanotubes can be used for high resolution scanning imaging. Or some nanostructured material, such as metal nanoparticles or nanowires, may also be used as electrode tips. These materials are generally capable of providing higher surface activity and more sensitive electrochemical responses. In some electrochemical systems, the tip may be made of a non-conductive material, such as fiberglass. Non-conductive tips are commonly used to measure potential or ion concentration profiles in solutions. The choice of tip material depends on the specific study requirements, sample properties, and the type of electrochemical reaction being studied. Different tip materials may produce different signal responses and imaging effects.
The electrode size at the tip of the sampling probe electrode is usually preferably in the micron level; the electrode size at the tip of the sampling probe electrode is typically on the order of microns or nanometers, with tip size being one of the key factors in determining its spatial resolution and performance. The geometry and size of the tip directly affects the resolution and perceptibility of the substrate surface microstructure. The electrode has many characteristics such as negligible ohm drop, small electric double layer capacitor charging process, high mass transfer rate and the like.
The substrate on the electrochemical sample stage is provided with a reference electrode and an auxiliary electrode, and a three-electrode system is formed by the reference electrode and the auxiliary electrode and the sampling probe electrode.
When the test is started, electrolyte, a substrate and a catalyst are supplemented to an electrochemical sample stage, an outer metal electrode layer at the tip end of a sampling probe electrode is connected with a potential controller, and two different potentials are simultaneously applied between the sampling probe electrode and the substrate through the potential controller so as to detect the dynamic and surface property changes of the electrochemical reaction. And opening a data recording project of the trace gas analysis module through a system controller to observe the concentration and the type of the produced gas. The potential controller can accurately control and measure the voltage and current of the substrate and the probe, so as to realize the monitoring of different electrochemical reactions; the sampling probe electrodes may be arranged in an array, which in turn constitutes an array tip, identifying and collecting electrochemical signals and products at multiple sites on the substrate. The array type tip can be connected with the trace gas analysis module at the same time, so that products at a plurality of points can be collected and detected.
The substrate part of the electrochemical sample stage is sequentially connected with a plurality of first stepping motors, a first XYZ coordinate stage and a displacement controller and is used for moving the substrate. The substrate surface is the X, Y plane, Z represents the vertical direction from the sampling probe electrode to the substrate surface. The probe can scan in the X, Y and Z directions, current signals corresponding to different coordinate positions are monitored, and the sampling electrode probe scans and identifies different parts of the substrate; the first stepping motors, the first XYZ coordinate tables and the displacement controllers are all uniformly controlled by the main controller, so that micron-level movement is realized.
The main controller controls the potential and the movement of the substrate, and analyzes, identifies, images and the like the current signals generated by the sample in the electrochemical sample stage and the sampling probe electrode. The raw current or potential data is acquired in the form of an image or data, where each data point corresponds to a location on the sample surface. At the same time, the trace gas analysis module records the yield, rate and type of product gas. Through data processing, the in-situ real-time coupling of electrochemical signals at different positions in the electrochemical field with data such as total product quantity, speed and variety can be realized, and an appropriate electrochemical model is used for explaining experimental results, so that a deeper understanding of electrochemical reaction mechanisms can be provided.
After the preparation of the sampling probe electrode and the assembly of the trace gas analysis module are completed, analysis is performed aiming at the electrochemical catalysis process of the copper catalyst. When the vacuum degree of the vacuum chamber reaches 10 -8～10-9 mbar, after the sampling module is connected with the gas analysis module, micro-current starts to be applied for testing, gas information is recorded at the same time, pmol-level gas production can be detected, and the result is consistent with the theoretical yield. As the applied electrochemical signal changes, the gas production changes. The device was still running steadily after 72 hours and gas products could still be detected steadily after electrochemical signal was applied to the sampling probe electrode. By optimizing the ion source parameters and the electromagnetic ferromagnetic field strength and using vacuum equipment with higher vacuum, fmol-level gas production can be detected.
Through the test, the sampling detection system provided by the invention can realize fmol-level gas production test, and can help practitioners and scientific researchers in the field of energy catalysis to conduct deep research on a trace product system; the device can realize the coupling of electrochemical signals and product signals, and is beneficial to realizing the in-situ real-time analysis of a catalytic system; the equipment can stably operate for a long time; the device provided by the invention also has a sampling probe electrode with high integration level, is suitable for various electrochemical systems, is convenient and quick to assemble in a modularized manner, and has strong applicability.
Comparative example 1
A sampling probe with a tip without a metal layer and a hollow channel without a material for selectively penetrating gas and a gas analyzer without a high-gyratory ionization ion source containing an electromagnet are used for testing an electrochemical catalysis process of a copper catalyst, when the vacuum degree of a vacuum chamber reaches 10 -8～10-9 mbar, after immersing a capillary tube, current is applied for testing, gas information is recorded at the same time, after 5 seconds, capillary tube blocking phenomenon occurs, and the water content is increased from below 1% to above 90%. Further observe the condition after water content rises, find that the gas that detects is the battery, and the entering of water also can damage the filament, reduces the life of ion source.
Comparative example 2
A sampling probe with a metal layer at the tip and a high-cyclotron ionization ion source without an electromagnet arranged in a hollow channel are used for testing an electrochemical catalysis process of a copper catalyst, when the vacuum degree of a vacuum chamber reaches 10 -8～10-9 mbar, a capillary tube is connected with the electrochemical probe, then current is applied for testing, gas information is recorded at the same time, and when theoretical gas yield is pmol along with the change of the current, compared with a baseline when the test is not started, the gas detected by the gas analyzer has no obvious change. I.e. no pmol level of gas production could be detected.
The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are also intended to be considered as protective scope of the present invention.
Claims (10)
1. The sampling probe electrode is characterized by comprising a sampling probe electrode body with a tip and a hollow channel, wherein a plurality of mutually insulated metal electrode layers are coated outside the tip, the hollow channel is filled with a filling material which is selectively permeable to gas, and the filling material comprises a polymer film and/or a metal organic framework MOF material.
2. The sampling probe electrode of claim 1, wherein the sampling probe electrode body is a glass capillary.
3. The sampling probe electrode according to claim 1, wherein the tip is any one of carbon nanotubes, conductive rubber, conductive nanomaterials, and nonconductive materials;
Wherein the conductive nano metal material comprises metal nano particles or metal nano wires; the non-conductive material comprises glass fibers.
4. The sampling probe electrode of claim 1, wherein the metal electrode layer comprises an Au electrode layer and a Pt electrode layer.
5. An in-situ electrochemical micro-sampling detection system is characterized by comprising a main controller, a vacuum electrode sampling module and a trace gas analysis module;
The vacuum electrode sampling module comprises an electrochemical sample stage, a potential controller, a first XYZ coordinate stage, a displacement controller and at least one sampling probe electrode according to any one of claims 1-5;
The electrochemical sample platform is used for placing an electrochemical test sample, and a reference electrode and an auxiliary electrode are arranged at the substrate;
the potential controller is connected with the metal electrode layer of the sampling probe electrode and the main controller and is used for controlling electrochemical parameters of each electrode in the electrochemical reaction system;
The electrochemical sample stage is arranged on the first XYZ coordinate stage, and the first XYZ coordinate stage is connected with the displacement controller and the main controller and is used for controlling the displacement of the electrochemical sample stage in the three-dimensional space to change the position of the sampling probe electrode in the electrochemical field;
The sampling probe electrode is used for applying an electrochemical signal provided by the potential controller to an electrochemical field in the electrochemical sample stage and can selectively permeate gas generated by electrochemical reaction;
The trace gas analysis module is connected with the main controller and the sampling probe electrode and is used for collecting the gas permeated by the sampling probe electrode and ionizing and detecting the permeated gas.
6. The in situ electrochemical micro-sampling detection system of claim 5, wherein the trace gas analysis module comprises a sample injection capillary, a high cyclotron ionization ion source, a vacuum device, a mass analyzer, and a detection module;
the sample injection capillary is connected with the hollow channel of the sampling probe electrode and the high cyclotron ionization ion source, and the high cyclotron ionization ion source is sequentially connected with the mass analyzer and the detection module and is connected with the vacuum equipment; the detection module is connected with the main controller;
Under the action of vacuum equipment, gas selectively penetrating through the sampling probe electrode enters the high cyclotron ionization ion source through the sample injection capillary, the high cyclotron ionization ion source ionizes the gas to form charged ion beams, the charged ion beams enter the mass analyzer to be separated into charged particles with different masses, and the detection module detects currents generated by the charged particles with different masses.
7. The in situ electrochemical micro-sampling detection system of claim 5, wherein the plurality of sampling probe electrodes are distributed in an array.
8. The in situ electrochemical micro-sampling detection system of claim 7, wherein the vacuum electrode sampling module further comprises a multi-channel array sampler;
The multichannel array sample injector comprises a sleeve, a rotor arranged in the sleeve and a stepping motor used for driving the rotor to rotate in the sleeve; the sleeve is fixed on the second XYZ coordinate table, the second XYZ coordinate table and the stepping motor are connected with the displacement controller, and the rotation of an executing shaft of the stepping motor and the action of the second XYZ coordinate table are controlled by the displacement controller;
The sleeve is provided with a plurality of threaded holes communicated with the inner cavity of the sleeve along a thread line, and a sampling probe electrode is connected with the threaded holes by using a connecting capillary; the rotor is provided with a middle channel, the periphery is provided with micropores communicated with the middle channel, and the sample injection capillary is connected with the middle channel of the rotor;
The stepping motor drives the rotor to do spiral motion in the sleeve, the second XYZ coordinate table drives the sleeve to move along Z direction, when the micropore on the rotor corresponds to the threaded hole on the sleeve, gas generated at a certain position in the electrochemical field is pumped to the high-convolution ionization ion source to realize ionization of the gas, and then the current generated by the charged particles with different masses is detected by the detection module after the charged particles with different masses are separated by the mass analyzer.
9. The in situ electrochemical micro-sampling detection system of claim 6 or 8, wherein the separated charged ions in the high cyclotron ionization ion source are pulsed vertically into the mass analyzer.
10. The in-situ electrochemical micro-sampling detection system according to claim 6, wherein an electromagnet is arranged in the high cyclotron ionization ion source, and electrons emitted in the high cyclotron ionization ion source move spirally under the action of an electric field and a magnetic field; the gas is continuously introduced into the high cyclotron ionization ion source and ionized under the action of the vacuum equipment.
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