Electrochemical quartz crystal microbalance and electrochemical quartz crystal microbalance electrolytic tank thereof

Abstract

The utility model relates to an electrochemical quartz crystal microbalance and an electrochemical quartz crystal microbalance electrolytic tank, and belongs to the technical field of electrochemistry. The electrochemical quartz crystal microbalance electrolytic tank comprises a tank cover and a tank cover, a first electrode wire rod and a second electrode wire rod are embedded into one side of the tank cover, a gas pipe is detachably mounted on the tank cover and used for inputting or outputting gas into or out of a tank body, one end of the tank body is detachably connected with the tank cover, and the other end of the tank body is detachably connected with the tank cover. One end, far away from the cell cover, of the cell body is detachably connected with the base, and a quartz wafer is clamped and pressed between the base and the cell body. The air tightness of the electrolytic tank of the electrochemical quartz crystal microbalance is improved, the air pressure in the electrolytic tank is accurately monitored in real time, the impact disturbance of the air pressure fluctuation in the electrolytic tank on the working electrode during ventilation test is solved, the frequency baseline fluctuation amplitude of the working electrode is lower than 5Hz, the signal-to-noise ratio of frequency detection is greatly improved, and the test accuracy is improved. The sensitivity, the accuracy and the reproducibility of the frequency signal are improved, and effective detection on the electrochemical reaction of which the frequency signal change is only 10Hz is realized.

Description

Technical Field

[0001] The utility model belongs to the technical field of electrochemistry, and in particular relates to an electrochemical quartz crystal microbalance and an electrochemical quartz crystal microbalance electrolytic cell thereof. Background Art

[0002] The quartz crystal microbalance (QCM), also known as a piezoelectric quartz crystal sensor or a thickness shear mode sensor, is an ultra-high sensitivity technology that can detect nanogram-level mass changes. It was developed in the 1960s, and its basic principle is the reverse voltage effect and the famous Sauerbrey equation. In the early days, QCM was mainly used to monitor the deposition rate of thin films and the determination of trace components in the gas phase in ultra-high vacuum systems; afterwards, the QCM theory and its application were further expanded. In the 1980s, the QCM with single-sided contact with liquid obtained stable oscillation in the liquid phase, and QCM technology began to be used in electrochemical research, opening up a new field of QCM application.

[0003] Electrochemical quartz crystal microbalance is a new detection and characterization technology developed by combining traditional liquid phase QCM technology and electrochemical technology. Since EQCM simultaneously utilizes the high sensitivity of electrochemical detection and the characteristics of QCM that can detect surface mass and damping in real time, it can detect nanogram-level mass changes on the electrode surface, solution viscosity and density properties, and changes in parameters such as the viscoelasticity of the modified film. The amount of information obtained is far richer than that of simple electrochemical detection. It has very good application prospects in the analysis and research of electrochemical processes and has begun to be used more and more widely. In the early 1990s, commercial EQCM instruments appeared, which greatly facilitated the application of QCM in electrochemical research. EQCM mainly consists of three parts: electrochemical workstation, oscillator and electrochemical quartz crystal microbalance electrolytic cell.

[0004] Therefore, for similar processes such as hydrogen oxidation under ventilation, the noise signal is strong and the effective signal is weak. How to reduce noise, improve the signal-to-noise ratio, and obtain a reliable frequency signal is the key to developing a high-sensitivity and high-stability electrochemical quartz crystal microbalance system. Utility Model Content

[0005] The applicant has found that the electrochemical quartz crystal microbalance electrolytic cell in the prior art has the following technical problems:

[0006] (1) Ordinary commercial electrochemical quartz crystal microbalance electrolytic cells are small in size and light in weight, only about 50 g. For laboratory use, it is difficult to have a noise-free environment, so their stability is poor; the small size makes it difficult to introduce gas purge and atmosphere protection processes. Commercial electrochemical quartz crystal microbalance electrolytic cells are designed for biochemical systems and have a volume of only 3 ml. For biochemical systems, this helps save expensive experimental materials, but it becomes a disadvantage for aqueous solution electrochemical systems. It can only use specific CE (counter electrode) and RE (reference electrode), which has great limitations.

[0007] (2) Ordinary commercial electrochemical quartz crystal microbalance electrolytic cells cannot achieve system sealing. The applicant found that commercial electrochemical quartz crystal microbalance electrolytic cells CE and RE are directly inserted into the electrochemical quartz crystal microbalance electrolytic cell through two openings on the electrochemical quartz crystal microbalance electrolytic cell cover. Without sealing, gas will leak from the openings of the electrode and the cover, which is extremely unfavorable for many electrochemical tests that require gas participation; it greatly limits the application of EQCM in electrochemical testing.

[0008] (3) Any electrochemical process on the electrode surface will cause the charge and mass on the electrode surface to change synchronously. The change in charge is mainly reflected in the conventional electrochemical signal of current-voltage, while the change in mass is detected by the QCM and reflected in the frequency change (Δf) detected by the electrode. By analyzing the ratio of the charge and mass (i.e., frequency) signals, the mass-to-charge ratio of the electrochemical reaction can be obtained, which can help analyze the electrochemical reaction mechanism. For example, the oxidation-desorption process of underpotential hydrogen on the Pt surface (which is also the Volmer step of hydrogen electrooxidation) is taken as an example. If H* →H + + * + e - In this process, the mass-to-charge ratio is -1 g / mol; if the interfacial water participates in the reaction, H2O+ 2 H* →2H + + *H2O* + 2e - , then its mass-to-charge ratio will be 8 g / mol. It can be seen that accurate and synchronous tracking of mass and charge changes in electrochemical processes is of great significance for studying many electrochemical surface and interface processes. However, for reactions such as the Volmer step, the mass change is extremely small, and the corresponding effective frequency change signal Δf is also extremely small, and may even be lower than 10 Hz. If the noise frequency is Δf0, in order to obtain a good signal-to-noise ratio (Δf / Δf0), the stability of the QCM electrode is extremely high, which means that the noise frequency fluctuation must also be controlled within a few Hz, otherwise the signal-to-noise ratio will be extremely low and the data quality will be too poor.

[0009] (4) For electrochemical processes that require ventilation, such as hydrogen electro-oxidation, in addition to gas sealing, the current design lacks precise control of the gas pressure inside the electrolytic cell chamber. During continuous ventilation, the fluctuation amplitude of the gas pressure inside the chamber is difficult to control. The change in gas pressure will disturb the electrolyte, causing the working electrode surface to be continuously subjected to irregular impact force, ultimately causing fundamental frequency signal oscillation and weakening the signal-to-noise ratio.

[0010] The final result of the above factors is that the test baseline is not stable. For most electrochemical processes, especially for the aforementioned hydrogen-to-electricity conversion electrocatalytic process such as the Volmer step (H* à * + H + + e - ), the mass changes in the adsorption and reaction processes are very small, which may only be reflected in the EQCM as a frequency change of a few Hz or tens of Hz. Therefore, this electrochemical quartz crystal microbalance electrolytic cell is completely unable to meet our test requirements.

[0011] In order to solve the above technical problems, the utility model provides an electrochemical quartz crystal microbalance and an electrochemical quartz crystal microbalance electrolytic cell thereof.

[0012] In a first aspect, the utility model provides an electrochemical quartz crystal microbalance electrolytic cell.

[0013] In some embodiments, an electrochemical quartz crystal microbalance electrolytic cell comprises,

[0014] A pool cover, wherein the first electrode conductor rod and the second electrode conductor rod are embedded in one side of the pool cover, and the pool cover is also detachably provided with an air pipe, and the air pipe is used to input or output gas to the pool body,

[0015] One end of the pool body is detachably connected to the pool cover, and one end of the pool body away from the pool cover is detachably connected to the base, and a quartz wafer is clamped between the base and the pool body.

[0016] In some embodiments, the air pipe includes an air inlet pipe and an air outlet pipe, and the air inlet pipe and the air outlet pipe are provided with a control valve for controlling the flow of gas, and when the control valve is turned off, the electrochemical quartz crystal microbalance electrolytic cell forms a sealed space. The utility model can greatly improve the baseline stability in the electrochemical test, avoid the curve sinking during the CV test, and is conducive to greatly improving the sensitivity, accuracy and reproducibility of the electrochemical detection by arranging the electrochemical quartz crystal microbalance electrolytic cell into a sealed space with good sealing when the control valve is turned off.

[0017] In some embodiments, the pool cover is provided with a plurality of air flow channels, the air flow channels comprising a first through hole and a second through hole connected by a reducing port, the first through hole and the second through hole are both provided with internal threads,

[0018] The air inlet pipe passes through the first joint, and the internal thread of the first through hole matches the external thread provided on the first joint.

[0019] The air outlet pipe is connected to the second joint, the second joint is connected to one end of the double-headed joint thread, and the internal thread of the second through hole is matched with the other end thread of the double-headed joint.

[0020] In some embodiments, the variable diameter opening is a stepped channel opening that is wider at the top and narrower at the bottom.

[0021] In some embodiments, a first annular seal is further placed in the first through hole, and when the first joint is screwed into the thread groove of the first through hole, the first annular seal is pressed against the diameter reducing port and deformed. After the first annular seal is deformed, it is helpful to prevent the gas inside and outside the electrochemical quartz crystal microbalance electrolytic cell from communicating through the connection gap, and it is also helpful to fix the air inlet pipe.

[0022] In some embodiments, the air inlet pipe passes through the first joint and the air flow channel and penetrates into the electrochemical quartz crystal microbalance electrolytic cell body.

[0023] In some embodiments, the depth of the air inlet pipe extending into the pool body is adjustable.

[0024] In some embodiments, a second annular seal is provided between the second joint and the double-ended joint.

[0025] In some embodiments, the air outlet pipe passes through a second joint and a double-ended joint, the second joint is connected to one end of the double-ended joint thread, and the internal thread of the second through hole is matched with the other end thread of the double-ended joint; a second annular seal is padded between the second joint and the double-ended joint, and when the second joint is spirally connected to the double-ended joint, the second annular seal is deformed; a sixth annular seal is also placed in the first through hole, and when the double-ended joint is screwed into the thread groove of the second through hole, the sixth annular seal is pressed against the reducing port and deformed.

[0026] In some embodiments, the air outlet pipe has a flanged pipe opening, which means that there is an annular protrusion at the pipe opening, and the protrusion is perpendicular to the pipeline direction.

[0027] In some embodiments, the air outlet pipe has a flanged pipe opening; the air outlet pipe passes through the second joint and the double-ended joint, the second joint is connected to one end of the double-ended joint thread, and the internal thread of the second through hole is matched with the thread of the other end of the double-ended joint; a second annular seal is padded between the second joint and the double-ended joint, and when the second joint is spirally connected to the double-ended joint, the second annular seal is deformed; a sixth annular seal is also placed in the first through hole, and when the double-ended joint is screwed into the thread groove of the second through hole, the sixth annular seal is pressed against the reducing port and deformed; the flanged pipe opening of the air outlet pipe is clamped between the sixth annular seal and the double-ended joint. The flanged pipe opening of the air outlet pipe is clamped between the sixth annular seal and the double-ended joint, which is beneficial to prevent the air outlet pipe from being rushed out by the internal positive pressure gas on the one hand, and on the other hand, it is beneficial to improve the air tightness of the connection position.

[0028] In some embodiments, the air outlet pipe has a flanged pipe opening; the air outlet pipe passes through the second joint and does not pass through the double-headed joint, the second joint is connected to one end of the double-headed joint thread, and the internal thread of the second through hole is matched with the thread of the other end of the double-headed joint; a second annular seal is padded between the second joint and the double-headed joint, and when the second joint is spirally connected to the double-headed joint, the second annular seal is deformed; a sixth annular seal is also placed in the first through hole, and when the double-headed joint is screwed into the thread groove of the second through hole, the sixth annular seal is pressed against the diameter reducing port and deformed; the flanged pipe opening of the air outlet pipe is clamped between the second annular seal and the second joint. The flanged pipe opening of the air outlet pipe is clamped between the second annular seal and the second joint, which is conducive to improving the air tightness of the connection position. The flanged pipe opening of the air outlet pipe is clamped between the second annular seal and the second joint, which is conducive to preventing the air outlet pipe from being rushed out by the internal positive pressure gas on the one hand, and on the other hand, it is conducive to improving the air tightness of the connection position.

[0029] The air outlet pipe of the utility model adopts a flange pipe mouth, which, on the one hand, helps to prevent the air outlet pipe from being rushed out by the internal positive pressure gas; on the other hand, the flange pipe mouth and the second annular seal or the sixth annular seal form a tight combination after the second joint is spirally connected to the double-headed joint or the double-headed joint is screwed into the threaded groove of the second through hole, which helps to improve the air tightness of the connection position; on another hand, the air outlet pipe adopts a flange pipe mouth, which helps to prevent the air outlet pipe body from being squeezed for a long time and causing damage and leakage of the pipeline.

[0030] In some embodiments, the first electrode conductor rod and the second electrode conductor rod are integrally embedded in the pool cover. The integral embedding means that the first electrode conductor rod and the second electrode conductor rod are inserted into the pool cover when casting the pool cover, or the gap between the first electrode conductor rod and the second electrode conductor rod and the pool cover is filled with an adhesive, so that the first electrode conductor rod and the second electrode conductor rod are closely integrated with the pool cover without gaps.

[0031] The utility model greatly improves the air tightness of the electrochemical quartz crystal microbalance electrolytic cell by integrally embedding the first electrode lead rod and the second electrode lead rod into the cell cover, thereby greatly improving the baseline stability in the electrochemical test, avoiding the curve from sinking during the CV test, and being beneficial to greatly improving the sensitivity, accuracy and reproducibility of the electrochemical detection.

[0032] In some embodiments, the first electrode lead rod is detachably connected to the counter electrode or the reference electrode by means of an insertion connection.

[0033] In some embodiments, the second electrode lead rod is detachably connected to the counter electrode or the reference electrode by means of an insertion connection.

[0034] In some embodiments, the first electrode lead rod and the second electrode lead rod are independently selected from the following settings:

[0035] (i) One end of the first electrode conductor rod or the second electrode conductor rod passes through the upper surface of the pool cover and is sealed; the other end is fixed to the lower surface of the pool cover without protruding and has a slot.

[0036] In some embodiments, the first electrode lead rod and the second electrode lead rod are independently selected from the following settings:

[0037] (ii) One end of the first electrode lead rod or the second electrode lead rod passes through the lower surface of the pool cover and is sealed, and the other end is fixed to the upper surface of the pool cover without protruding and has a slot.

[0038] In some embodiments, the first electrode lead rod and the second electrode lead rod are independently selected from the following settings:

[0039] (iii) the first electrode conductor rod or the second electrode conductor rod passes through the pool cover and extends out from both the upper surface and the lower surface of the pool cover, at least one of the two ends of the first electrode conductor rod is closed, and at least one of the two ends of the second electrode conductor rod is closed.

[0040] In some embodiments, the first electrode lead rod and the second electrode lead rod are independently selected from the following settings:

[0041] (iv) The first electrode lead rod or the second electrode lead rod is arranged in the pool cover, one end of the first electrode lead rod or the second electrode lead rod is fixed to the upper surface of the pool cover without protruding and a slot is formed at the end, and the other end of the first electrode lead rod or the second electrode lead rod is fixed to the surface of the pool cover without protruding and a slot is formed at the end.

[0042] The utility model connects the first electrode lead rod or the second electrode lead rod to the counter electrode or the reference electrode through an inserting connection method, which is convenient for users to replace different electrodes and can meet the user's requirements for a variety of counter electrodes and reference electrodes (such as counter electrodes and reference electrodes of different sizes and materials). In addition, the counter electrode and the reference electrode can be completely placed inside the closed electrochemical quartz crystal microbalance electrolytic cell, and the electrochemical quartz crystal microbalance electrolytic cell is led out through the first electrode lead rod or the second electrode lead rod, and connected to the electrochemical workstation. This method can ensure that the electrochemical quartz crystal microbalance electrolytic cell (EQCM electrochemical quartz crystal microbalance electrolytic cell) is absolutely sealed at the first electrode lead rod and the second electrode lead rod; the improvement of airtightness is conducive to improving the baseline stability in electrochemical testing, avoiding the sinking of the curve during the CV test, and is conducive to improving the sensitivity, accuracy and reproducibility of electrochemical detection.

[0043] In some embodiments, the pool body is an open cylindrical container, the upper opening of the pool body is provided with an internal thread, the bottom of the pool cover is provided with a protrusion, the protrusion is provided with an external thread, the protrusion is covered with a third annular seal, and the pool cover is connected to the pool body by threads. The pool body of the utility model is connected to the bottom of the pool cover by threads, which is beneficial to the tightness of the connection between the pool body and the pool cover. The utility model is beneficial to improving the air tightness between the pool body and the pool cover by covering the protrusion at the bottom of the pool cover with a third annular seal. The improvement of air tightness is beneficial to improving the baseline stability in electrochemical testing, avoiding the sinking of the curve during the CV test, and improving the sensitivity, accuracy and reproducibility of electrochemical detection.

[0044] In some embodiments, the pool body is an open cylindrical container with a small hole at the bottom of the pool body. The quartz chip is arranged between the pool body and the base and is located directly below the small hole. A fourth annular seal is placed above the quartz chip and a fifth annular seal is placed below the quartz chip.

[0045] In some embodiments, the fourth annular seal is clamped between the cell body and the quartz wafer.

[0046] In some embodiments, the fifth annular seal is clamped between the base and the quartz wafer.

[0047] The utility model is beneficial to improving the air tightness of the EQCM electrochemical quartz crystal microbalance electrolytic cell by arranging the fourth annular seal and the fifth annular seal, and at the same time avoiding leakage of liquid inside the EQCM electrochemical quartz crystal microbalance electrolytic cell during detection.

[0048] In some embodiments, two narrow holes are provided on the bottom of the pool body and the upper surface of the base, and the input and output lines of the quartz wafer are respectively located in the two narrow holes.

[0049] In some embodiments, the two narrow holes at the bottom of the pool body are opposite to the two narrow holes on the upper surface of the base to form two channels, and the inlet and outlet lines of the quartz wafer are respectively located in the two channels.

[0050] In some embodiments, a quartz wafer electrode holder groove is provided on the bottom of the pool body and the upper surface of the base for placing the electrode holder of the quartz wafer.

[0051] In some embodiments, the base is fixed to the electrochemical quartz crystal microbalance electrolytic cell body by a screw.

[0052] In some embodiments, the volume of the electrochemical quartz crystal microbalance electrolytic cell is 30ml-50ml. Ordinary commercial electrochemical quartz crystal microbalance electrolytic cells have a small overall size. For laboratory use, it is difficult to have a noise-free environment, so their stability is poor; the small size makes it difficult to introduce gas purge and atmosphere protection processes. The commercial electrochemical quartz crystal microbalance electrolytic cell is designed for biochemical systems and has a volume of only 3 ml. It is beneficial to save expensive experimental materials for biochemical systems, but it becomes a disadvantage for electrochemical systems of aqueous solutions. It can only use specific CE and RE, which has great limitations; for most electrochemical processes, the quality changes in the adsorption and reaction processes are very small, which may only be reflected in the EQCM. The frequency change of tens of Hz, the ordinary commercial electrochemical quartz crystal microbalance electrolytic cell is too small, and the baseline jumps at about 30Hz, which is not conducive to the stability of the baseline, and its sensitivity and reproducibility are poor. The utility model sets the volume of the electrochemical quartz crystal microbalance electrolytic cell to 30ml-50ml, and the expansion of the volume is conducive to the introduction of gas purge and atmosphere protection processes, thereby greatly improving the baseline stability in the electrochemical test, and is conducive to improving the sensitivity, accuracy and reproducibility of electrochemical detection.

[0053] In some embodiments, the total weight of the cell body, quartz wafer, base and cell cover is 350g-500g. The overall weight of an ordinary commercial electrochemical quartz crystal microbalance electrolytic cell is light, only about 50 g. For laboratory use, it is difficult for us to have a noise-free environment, so its stability is poor, which will cause the test baseline to be unstable. For most electrochemical processes, the mass changes in the adsorption and reaction processes are very small, which may only reflect the frequency changes of tens of Hz on the EQCM. The volume of an ordinary commercial electrochemical quartz crystal microbalance electrolytic cell is too small, and the baseline jumps at about 30Hz, which is not conducive to the stability of the baseline, and its sensitivity and reproducibility are poor. The utility model increases the weight of the electrochemical quartz crystal microbalance electrolytic cell, thereby reducing the interference of the external environment on the test baseline, improving the signal-to-noise ratio, and is conducive to improving the sensitivity, accuracy and reproducibility of electrochemical detection.

[0054] In some embodiments, the pool body, base and pool cover are made of polytetrafluoroethylene or acrylic.

[0055] In some embodiments, the pool body is made of acrylic, and the base and the pool cover are made of polytetrafluoroethylene.

[0056] In some embodiments, the cell body is made of transparent acrylic, and the base and the cell cover are made of polytetrafluoroethylene. The cell body is made of transparent acrylic, which is conducive to real-time observation of the internal conditions of the electrochemical quartz crystal microbalance electrolytic cell and is conducive to control during ventilation.

[0057] In a second aspect, the utility model provides an electrochemical quartz crystal microbalance.

[0058] In some embodiments, an electrochemical quartz crystal microbalance includes an inlet control valve, the electrochemical quartz crystal microbalance electrolytic cell of the first aspect, a pressure gauge, an outlet control valve, an electrochemical workstation and an oscillator.

[0059] In some embodiments, the electrochemical quartz crystal microbalance further comprises an electronic gas flow meter.

[0060] In some embodiments, the air inlet control valve or the air outlet control valve is selected from a precision flow control valve. The utility model uses a precision flow control valve as the air inlet control valve or the air outlet control valve, which is conducive to achieving precise control of the gas flow rate, and is conducive to achieving precise control of the internal air pressure of the electrochemical quartz crystal microbalance electrolytic cell, which is conducive to improving the detection stability of the electrochemical quartz crystal microbalance electrolytic cell.

[0061] In some embodiments, the minimum precision unit of the electronic gas flow meter is 1 ml / min. A high-precision electronic gas flow meter is conducive to achieving precise control of the gas flow rate, precise control of the internal gas pressure of the electrochemical quartz crystal microbalance electrolytic cell, and improving the detection stability of the electrochemical quartz crystal microbalance electrolytic cell.

[0062] In some embodiments, the minimum precision unit of the pressure gauge is 1 Pa. A high-precision pressure gauge is conducive to achieving precise control of gas flow rate, precise control of the internal gas pressure of the electrochemical quartz crystal microbalance electrolytic cell, and improving the detection stability of the electrochemical quartz crystal microbalance electrolytic cell.

[0063] In some embodiments, the air inlet control valve is connected to the air inlet pipe of the electrochemical quartz crystal microbalance electrolytic cell described in the first aspect, the pressure gauge and the air outlet control valve are connected to the air outlet pipe of the electrochemical quartz crystal microbalance electrolytic cell described in the first aspect, the first electrode lead rod and the second electrode lead rod of the electrochemical quartz crystal microbalance electrolytic cell described in the first aspect are respectively connected to the electrochemical workstation via wires, and the oscillator is connected to the quartz chip of the electrochemical quartz crystal microbalance electrolytic cell described in the first aspect.

[0064] In some embodiments, the air inlet control valve and the electronic gas flowmeter are connected to the air inlet pipe of the electrochemical quartz crystal microbalance electrolytic cell described in the first aspect, the pressure gauge and the air outlet control valve are connected to the air outlet pipe of the electrochemical quartz crystal microbalance electrolytic cell described in the first aspect, the first electrode lead rod and the second electrode lead rod of the electrochemical quartz crystal microbalance electrolytic cell described in the first aspect are respectively connected to the electrochemical workstation via wires, and the oscillator is connected to the quartz chip of the electrochemical quartz crystal microbalance electrolytic cell described in the first aspect.

[0065] In some embodiments, the first annular seal, the second annular seal, the third annular seal, the fourth annular seal, the fifth annular seal, and the sixth annular seal are independently selected from rubber materials, plastic materials, or polyurethane materials.

[0066] In some embodiments, the rubber material includes nitrile rubber, hydrogenated nitrile rubber, silicone rubber, fluorine rubber, fluorosilicone rubber, EPDM rubber or polyurethane rubber.

[0067] In some embodiments, the plastic-like material includes polytetrafluoroethylene.

[0068] Beneficial Effects

[0069] Compared with the prior art, a certain embodiment of the utility model has at least one of the following beneficial effects:

[0070] (1) The utility model improves the air tightness of the electrochemical quartz crystal microbalance electrolytic cell by, for example, integrally embedding the first electrode lead rod and the second electrode lead rod into the cell cover, sealing by using a first annular seal, a second annular seal, a third annular seal, a fourth annular seal, a fifth annular seal and / or a sixth annular seal, and / or setting the outlet pipe opening as a flange pipe opening, thereby greatly improving the air tightness of the electrochemical quartz crystal microbalance electrolytic cell, thereby greatly improving the baseline stability in the electrochemical test, avoiding the curve sinking during the CV test, and facilitating greatly improving the sensitivity, accuracy and reproducibility of the electrochemical detection.

[0071] (2) The outlet pipe of the utility model adopts a flanged pipe mouth, which, on the one hand, helps to prevent the outlet pipe from being rushed out by the internal positive pressure gas; on the other hand, the flanged pipe mouth and the second annular seal or the sixth annular seal form a tight combination after the second joint is spirally connected to the double-headed joint or the double-headed joint is screwed into the thread groove of the second through hole, which helps to improve the air tightness of the connection position; on the other hand, the outlet pipe adopts a flanged pipe mouth, which helps to prevent the outlet pipe body from being squeezed for a long time and causing the pipe to be damaged and leak.

[0072] (3) The utility model increases the weight of the electrochemical quartz crystal microbalance electrolytic cell by enlarging the volume of the electrochemical quartz crystal microbalance electrolytic cell, reduces the impact of external environmental vibration, improves the signal-to-noise ratio, and greatly improves the stability of the electrochemical quartz crystal microbalance electrolytic cell; and the large volume can control the formation of a liquid part and a cavity part inside the electrochemical quartz crystal microbalance electrolytic cell, and at the same time, by controlling the gas flow rate, the system can be kept stable even if gas is introduced.

[0073] (4) The counter electrode and the reference electrode of the utility model adopt an interpolation design (that is, the counter electrode and the reference electrode can be completely placed inside the sealed electrochemical quartz crystal microbalance electrolytic cell, and are led out of the electrochemical quartz crystal microbalance electrolytic cell through a wire. This method can ensure that these two parts of the EQCM (electrochemical quartz crystal microbalance) electrochemical quartz crystal microbalance electrolytic cell are absolutely sealed. The electrochemical quartz crystal microbalance electrolytic cell with good sealing performance can be applied to a variety of electrodes and has good operability.

[0074] (5) We solved the above problems by making targeted designs on the details of the electrochemical quartz crystal microbalance electrolytic cell cover. The built-in counter electrode and reference electrode are highly compatible, and the two electrode wire rods are directly buried in the cell cover, so the electrochemical quartz crystal microbalance electrolytic cell can be absolutely sealed, and the internal chamber of the cell can be kept at a stable positive pressure; for our high-airtightness ventilated electrochemical quartz crystal microbalance electrolytic cell and EQCM system overall design, by controlling the air inlet mass flow controller and the outlet valve on both sides of the system, the pressure is monitored in real time by a precision pressure gauge. On the one hand, this keeps the air pressure in the upper chamber of the electrochemical quartz crystal microbalance electrolytic cell constant, and the air pressure fluctuation range is at the Pa level, thereby effectively reducing the noise caused by the pressure change during the ventilation process impacting the QCM electrode and the fundamental frequency; on the other hand, this can keep a certain positive pressure inside the chamber relative to the atmospheric pressure in real time, preventing the oxygen in the air from continuously dissolving into the electrolyte and the saturated gas in the solution from continuously overflowing. The overall design of the electrochemical quartz crystal microbalance electrolytic cell is easy to operate, visualized, quantifiable, and highly adaptable.

[0075] (6) The utility model adopts a precision flow control valve as an air inlet control valve or an air outlet control valve, which is conducive to realizing precise control of the gas flow rate, and is conducive to realizing precise control of the internal gas pressure of the electrochemical quartz crystal microbalance electrolytic cell, and is conducive to improving the detection stability of the electrochemical quartz crystal microbalance electrolytic cell.

[0076] (7) The utility model adopts a high-precision electronic gas flow meter, which is conducive to achieving precise control of the gas flow rate, and is conducive to achieving precise control of the internal gas pressure of the electrochemical quartz crystal microbalance electrolytic cell, and is conducive to improving the detection stability of the electrochemical quartz crystal microbalance electrolytic cell.

[0077] (8) The utility model adopts a high-precision pressure gauge, which is conducive to achieving precise control of the gas flow rate, and is conducive to achieving precise control of the internal gas pressure of the electrochemical quartz crystal microbalance electrolytic cell, and is conducive to improving the detection stability of the electrochemical quartz crystal microbalance electrolytic cell.

[0078] (9) The electrochemical quartz crystal microbalance electrolytic cell of the utility model is used to perform CV test (cyclic voltammetry test). Whether the curve sinks during the CV test can accurately reflect the dissolved oxygen in the system, thereby reflecting the sealing performance. This is also a key point of our design improvement. It is crucial for electrochemical testing. The electrochemical quartz crystal microbalance electrolytic cell described in the utility model can effectively solve the problem of curve sinking during the CV test, which shows that the electrochemical quartz crystal microbalance electrolytic cell designed by us has good sealing performance.

[0079] (10) The frequency baseline is tested by the electrochemical quartz crystal microbalance electrolytic cell of the utility model. The frequency baseline oscillation amplitude is crucial, especially under ventilation conditions. If the frequency baseline oscillation (Δf0) reaches tens of Hz, the signal-to-noise ratio Δf / Δf0 will be too low for electrochemical reactions with effective frequency signal changes (Δf) less than 10Hz. The utility model can control the fundamental frequency amplitude within 5Hz, which is crucial for the high signal-to-noise ratio of subsequent electrochemical process detection, indicating that the stability of the QCM working electrode in the utility model is significantly improved.

[0080] (11) The electrochemical quartz crystal microbalance electrolytic cell of the utility model is used to test the charge (i.e., CV curve) and frequency-voltage curve (Δf~V) curve of the polycrystalline Pt surface in the range of 0-1.2V (vs RHE). The voltage range includes three electrochemical processes: underpotential hydrogen adsorption and desorption range, double electric layer region, and oxygen region. The oxidation and desorption of underpotential hydrogen (H* à* + H) in different electrolytes (solutions with different pH values, different acids or bases) are tracked and analyzed. + + e - ) and the mass-to-charge ratio Δf~Q curve (Q is the corresponding process integrated electricity) are the main focus of our design improvement. This is because the frequency signal involved in the electrochemical reaction changes by only a few Hz to a dozen Hz. Therefore, if the system repeatedly detects the difference or regularity of the frequency signal of the process under different conditions, it means that it can reflect the stability and precision of the detection system. The electrochemical quartz crystal microbalance electrolytic cell described in the utility model has been found to have significant differences in the oxidation and desorption of underpotential hydrogen on the surface of polycrystalline Pt (i.e., the Volmer step) at different pH values, and the data is highly repeatable, indicating that a qualitative improvement in the quality of frequency data has been achieved.

[0081] Terminology

[0082] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] In order to facilitate understanding by those skilled in the art, some structures are omitted in some of the following figures. For example, the air inlet control valve 1151 and the air outlet control valve 1152 are omitted in some electrolytic cells in each figure.

[0084] Figure 1a This is a test chart of the frequency baseline of an electrochemical quartz crystal microbalance using a commercial electrochemical quartz crystal microbalance electrolytic cell in a ventilated state in Example 7.

[0085] Figure 1b This is a frequency baseline test diagram of the electrochemical quartz crystal microbalance A of the utility model in a non-ventilated state.

[0086] Figure 1c This is a frequency baseline test diagram of the electrochemical quartz crystal microbalance A of the utility model in the ventilation state.

[0087] Figure 2 This is a frequency baseline test diagram of the utility model electrochemical quartz crystal microbalance A in Example 7 when the cell cover 1 is opened and the balance is in an unsealed state.

[0088] Figure 3A This is an exploded view of the cell cover 1 of the electrochemical quartz crystal microbalance electrolytic cell 9 described in any one of Examples 1 to 2.

[0089] Figure 3B This is a three-dimensional diagram of the electrochemical quartz crystal microbalance electrolytic cell 9 described in any one of Examples 1 to 3 in a state where the cell cover 1, cell body 2 and base 3 are not tightly combined.

[0090] Figure 4 This is a bottom view of the cell cover 1 of the electrochemical quartz crystal microbalance electrolytic cell 9 described in any one of Examples 1 to 3.

[0091] Figure 5A-1 This is a cross-sectional view of the electrochemical quartz crystal microbalance electrolytic cell 9 described in Example 3, in which the cell cover 1 with setting b is cut along the direction of the air inlet pipe 1031 and the air outlet pipe 1032; except for the dotted line in area B, the other dotted lines are boundary lines that are invisible to the naked eye in the cross-sectional view.

[0092] Figure 5A-2 for Figure 5A-1 A partial enlarged view of area B.

[0093] Figure 5B-1 This is a cross-sectional view of the electrochemical quartz crystal microbalance electrolytic cell 9 described in Example 3, in which the cell cover 1 with setting a is cut along the direction of the air inlet pipe 1031 and the air outlet pipe 1032; except for the dotted line in area C, the other dotted lines are boundary lines that are invisible to the naked eye in the cross-sectional view.

[0094] Figure 5B-2 for Figure 5B-1A partial enlarged view of the C area.

[0095] Figure 5C-1 This is a cross-sectional view of the electrochemical quartz crystal microbalance electrolytic cell 9 described in Example 1, in which the cell cover 1 with setting c is cut along the direction of the air inlet pipe 1031 and the air outlet pipe 1032; except for the dotted line in the D area, the other dotted lines are boundary lines that are invisible to the naked eye in the cross-sectional view.

[0096] Figure 5C-2 for Figure 5B-1 A partial enlarged view of area D.

[0097] Figure 6 It is an exploded view of the electrochemical quartz crystal microbalance electrolytic cell 9 described in any one of Examples 1 to 3.

[0098] Figure 7 It is an exploded view of the electrochemical quartz crystal microbalance electrolytic cell 9 described in any one of Examples 1 to 3.

[0099] Figure 8 1 is a top view of the cell body 2 of the electrochemical quartz crystal microbalance electrolytic cell 9 described in any one of Examples 1 to 4.

[0100] Fig. 9 This is a schematic diagram of the structure of the electrochemical quartz crystal microbalance described in Example 5.

[0101] Fig.10 This is a schematic diagram of the structure of the electrochemical quartz crystal microbalance described in Example 6.

[0102] Fig.11 The current-voltage variation curve (i.e., CV curve) measured by the electrochemical quartz crystal microbalance electrolytic cell provided by the utility model in the literature or in Example 8 of the utility model and the frequency Δf versus voltage variation curve (i.e., Δf~V curve) obtained synchronously in the above process;

[0103] in Fig.11 Figures a1-a2 in the middle are the CV curves (solid line) corresponding to the change in charge on the electrode surface caused by the electrochemical process and the frequency curves (dashed line) caused by the change in mass surface mass, which are measured by EQCM in the range of 0-1.0 V on the polycrystalline Pt surface under acidic conditions (underpotential hydrogen adsorption and desorption and oxygen zone reaction) in the literature (Electrochemistry Communications, 2000, 2, Page 692-696);

[0104] Fig.11 Figure b1 in the middle is a typical CV curve obtained by conducting a CV test in a sulfuric acid aqueous solution using the electrochemical quartz crystal microbalance electrolytic cell A of the utility model in Example 8;

[0105] Fig.11 Figure c1 in the middle is a typical CV curve obtained by performing a CV test in a perchloric acid aqueous solution using the electrochemical quartz crystal microbalance electrolytic cell A of the utility model in Example 8;

[0106] Fig.11 Figure b2 in Example 8 is a graph showing the frequency Δf versus voltage variation (i.e., Δf-V curve) obtained by using the electrochemical quartz crystal microbalance electrolytic cell A of the utility model to perform a CV test in a sulfuric acid aqueous solution;

[0107] Fig.11 Figure c2 in Example 8 is a graph showing the frequency Δf versus voltage variation (i.e., Δf-V curve) obtained by using the electrochemical quartz crystal microbalance electrolytic cell A of the utility model to perform a CV test in a perchloric acid aqueous solution;

[0108] Fig.11 Figure d1 in the middle is a typical CV curve obtained by performing a CV test in a KOH aqueous solution using the electrochemical quartz crystal microbalance electrolytic cell A of the utility model in Example 8;

[0109] Fig.11 Figure e1 in the middle is a typical CV curve obtained by performing a CV test in a NaOH aqueous solution using the electrochemical quartz crystal microbalance electrolytic cell A of the utility model in Example 8;

[0110] Fig.11 Figure d2 in the middle is a graph showing the frequency Δf versus voltage variation (i.e., Δf-V curve) obtained by using the electrochemical quartz crystal microbalance electrolytic cell A of the utility model in a CV test in a KOH aqueous solution in Example 8;

[0111] Fig.11 Figure e2 in the middle is a graph showing the frequency Δf versus voltage variation (i.e., Δf-V curve) obtained by using the electrochemical quartz crystal microbalance electrolytic cell A of the utility model to perform a CV test in a NaOH aqueous solution in Example 8;

[0112] Fig.11 Figures b3 / c3 / d3 / e3 in the middle are the Volmer steps *H à* + H corresponding to the hydrogen oxidation process under the corresponding conditions (b3 corresponds to the condition of sulfuric acid aqueous solution, c3 corresponds to the condition of perchloric acid aqueous solution, d3 corresponds to the condition of KOH aqueous solution, and e3 corresponds to the condition of NaOH aqueous solution) for the underpotential hydrogen oxidation desorption process (0-0.15V vs RHE range). + +e - ), after we obtain the integrated current Q (mC) of this process based on the current integration of the CV curve, the frequency change Δf in this interval is plotted against the change of the integrated charge Q.

[0113] Fig.12 This is a cross-sectional view of the first electrode lead rod 101 and the second electrode lead rod 102 in Example 4 using the cell cover 1 of the electrochemical quartz crystal microbalance with IV setting when the counter electrode 108, the reference electrode 109, the air inlet pipe 1031 and the air outlet pipe 1032 are not installed; the dotted line in the figure is the boundary line that is invisible to the naked eye in the cross-sectional view.

[0114] Fig.13 This is a cross-sectional view of the first electrode lead rod 101 and the second electrode lead rod 102 in the direction of the first electrode lead rod 101 and the second electrode lead rod 102 using the cell cover 1 of the electrochemical quartz crystal microbalance with setting ii in Example 4 when the counter electrode 108, the reference electrode 109, the air inlet pipe 1031 and the air outlet pipe 1032 are not installed; the dotted line in the figure is the boundary line that is invisible to the naked eye in the cross-sectional view.

[0115] Fig.14 This is a cross-sectional view of the first electrode lead rod 101 and the second electrode lead rod 102 in Example 1 using the cell cover 1 of the electrochemical quartz crystal microbalance with setting i without the counter electrode 108, the reference electrode 109, the air inlet pipe 1031 and the air outlet pipe 1032 installed; the dotted line in the figure is the boundary line that is invisible to the naked eye in the cross-sectional view.

[0116] Fig.15 This is a cross-sectional view of the first electrode lead rod 101 and the second electrode lead rod 102 in the direction of the first electrode lead rod 101 and the second electrode lead rod 102 using the cell cover 1 of the electrochemical quartz crystal microbalance with setting iii in Example 4 when the counter electrode 108, the reference electrode 109, the air inlet pipe 1031 and the air outlet pipe 1032 are not installed; the dotted line in the figure is the boundary line that is invisible to the naked eye in the cross-sectional view.

[0117] Fig.16 The graphs of the current and frequency versus voltage for the CO-stripping process in an acidic or alkaline solution as described in Example 9 and the corresponding mass-to-charge change Δf~Q graph are shown.

[0118] in, Fig.16 Figure a1 in the middle is a curve diagram showing the change of current versus voltage during the CO-stripping process in acid as described in Example 9.

[0119] Fig.16 Figure a2 in the middle is a curve diagram showing the frequency variation with voltage during the CO-stripping process in acid as described in Example 9.

[0120] Fig.16Figure a3 in the middle is a mass-to-charge change Δf~Q curve diagram of the CO-stripping process in acid as described in Example 9.

[0121] Fig.16 Figure b1 in the middle is a curve diagram showing the change of current versus voltage during the CO-stripping process in alkaline environment described in Example 9.

[0122] Fig.16 Figure b2 in the middle is a curve diagram showing the frequency variation with voltage in the CO-stripping process in alkaline environment as described in Example 9.

[0123] Fig.16 Figure b3 in the middle is a mass-to-charge change Δf~Q curve diagram of the CO-stripping process in alkaline environment described in Example 9.

[0124] In the accompanying drawings, the meanings of the symbols are as follows:

[0125] 1: Pool cover;

[0126] 101: first electrode wire rod; 102: second electrode wire rod; 103: trachea; 1031: air inlet pipe; 1032: air outlet pipe;

[0127] 104: air flow channel; 1041: first through hole; 1042: second through hole; 105: first joint; 106: second joint; 107: first annular seal; 108: counter electrode; 109: reference electrode; 110: slot; 111: second annular seal; 112: flange pipe opening;

[0128] 113: third annular seal; 114: sixth annular seal; 115: control valve; 1151: air inlet control valve; 1152: air outlet control valve; 116: double-end joint; 117: external thread;

[0129] 2: Pool body;

[0130] 201: internal thread; 202: channel; 203: small hole; 204: narrow hole;

[0131] 3: Base;

[0132] 301: Quartz wafer electrode support groove

[0133] 4: Quartz wafer;

[0134] 401: fourth annular seal; 402: fifth annular seal; 403: incoming line; 404: outgoing line; 405: electrode support;

[0135] 5: Screw; 6: Pressure gauge; 7: Electrochemical workstation; 8: Oscillator; 9: Electrolytic cell; 10: Electronic gas flow meter. DETAILED DESCRIPTION

[0136] In order to enable those skilled in the art to better understand the technical solution of the present invention, some non-limiting embodiments are further disclosed below to further illustrate the present invention in detail.

[0137] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0138] In the following description, spatial and directional terms such as "vertical" and "horizontal" may be used to describe the embodiments of the utility model, but it should be understood that these terms are only for the convenience of describing the embodiments shown in the figures, and do not require the actual device to be constructed or operated in a specific orientation. In the following description, the use of terms such as "connect", "couple", "fixed" and "attached" may refer to the direct connection between two elements or structures without other elements or structures, or may refer to the indirect connection between two elements or structures through an intermediate element or structure, unless otherwise explicitly stated in this document. The term "transmission connection" refers to the transmission of power and the relative movement caused by it between two or more elements or structures in a connection relationship.

[0139] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, or a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0140] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in combination with specific examples and with reference to the accompanying drawings. For the convenience of description, the "left", "right", "upper" and "lower" referred to below are consistent with the left, right, upper and lower of the accompanying drawings themselves, but do not limit the structure of the utility model.

[0141] The commercial electrochemical quartz crystal microbalance electrolysis cell described in the embodiment of the utility model is a CHI440C electrochemical quartz crystal microbalance electrolytic cell of Shanghai Chenhua Instrument Co., Ltd. The electrochemical quartz crystal microbalance electrolytic cell has a diameter of 35 mm and a total height of 37 mm.

[0142] Example 1: Electrochemical Quartz Crystal Microbalance Electrolytic Cell

[0143] Combination Figure 3A , Figure 3B , Figure 4 , Figure 5C-1 , Figure 5C-2 , Figure 6-Figure 8 , Fig.14 The electrochemical quartz crystal microbalance electrolytic cell 9 provided by the utility model is specifically described, and includes:

[0144] A pool cover 1, wherein a first electrode conductor rod 101 and a second electrode conductor rod 102 are embedded in one side of the pool cover 1, and the pool cover 1 is also detachably provided with an air pipe 103, wherein the air pipe 103 is used to input or output gas to the pool body 2,

[0145] One end of the pool body 2 is detachably connected to the pool cover 1, and the end of the pool body 2 away from the pool cover 1 is detachably connected to the base 3, and a quartz wafer 4 is clamped between the base 3 and the pool body 2;

[0146] The air pipe 103 includes an air inlet pipe 1031 and an air outlet pipe 1032, and the air inlet pipe 1031 and the air outlet pipe 1032 are provided with a control valve 115 for controlling the flow of gas. When the control valve 115 is closed, the electrochemical quartz crystal microbalance electrolytic cell 9 forms a sealed space;

[0147] The pool cover 1 is provided with a plurality of air flow channels 104, and the air flow channels 104 include a first through hole 1041 and a second through hole 1042 connected by a reducing port, and the first through hole 1041 and the second through hole 1042 are both provided with internal threads.

[0148] The air inlet pipe 1031 passes through the first connector 105, and the internal thread of the first through hole 1041 matches with the external thread provided on the first connector 105.

[0149] The air outlet pipe 1032 is connected to the second joint 106, the second joint 106 is connected to one end of the double-ended joint 116, and the internal thread of the second through hole 1042 is matched with the other end of the double-ended joint 116;

[0150] The variable diameter opening is a stepped channel opening that is wide at the top and narrow at the bottom;

[0151] The first through hole 1041 is also provided with a first annular seal 107. When the first joint 105 is screwed into the thread groove of the first through hole 1041, the first annular seal 107 is pressed against the reducing port and deformed.

[0152] The air inlet pipe 1031 passes through the first joint 105 and the air flow channel 104 and penetrates into the body 2 of the electrochemical quartz crystal microbalance electrolytic cell 9;

[0153] The depth of the air inlet pipe 1031 extending into the pool body 2 is adjustable;

[0154] A second annular seal 111 is provided between the second joint 106 and the double-ended joint 116;

[0155] The air outlet pipe 1032 adopts the following setting, which is referred to as setting c: the air outlet pipe 1032 passes through the second joint 106 and the double-headed joint 116, the second joint 106 is connected to one end of the double-headed joint 116 thread, and the internal thread of the second through hole 1042 is threadedly matched with the other end of the double-headed joint 116; a second annular seal 111 is padded between the second joint 106 and the double-headed joint 116, and when the second joint 106 and the double-headed joint 116 are spirally connected, the second annular seal 111 is deformed; a sixth annular seal 114 is also placed in the first through hole 1041, and when the double-headed joint 116 is screwed into the thread groove of the second through hole 1042, the sixth annular seal 114 is pressed against the reducing port and deformed; the cross-sectional view of the pool cover 1 adopting this setting is shown in Figure 5C-1 , Figure 5C-1 The partial enlarged view of the D area is shown in Figure 5C-2 ;

[0156] The first electrode conductor rod 101 and the second electrode conductor rod 102 are integrally embedded in the pool cover 1; the integral embedding means that the first electrode conductor rod 101 and the second electrode conductor rod 102 are inserted into the pool cover 1 when casting the pool cover 1, or the gap between the first electrode conductor rod 101 and the second electrode conductor rod 102 and the pool cover 1 is filled with an adhesive, so that the first electrode conductor rod 101 and the second electrode conductor rod 102 are closely combined with the pool cover 1 without gaps;

[0157] The first electrode lead rod 101 is detachably connected to the counter electrode 108 or the reference electrode 109 by means of a plug-in connection;

[0158] The second electrode lead rod 102 is detachably connected to the counter electrode 108 or the reference electrode 109 by means of a plug-in connection;

[0159] The first electrode conductor rod 101 and the second electrode conductor rod 102 are independently selected from the following settings, referred to as settings i: one end of the first electrode conductor rod 101 or the second electrode conductor rod 102 passes through the upper surface of the pool cover 1 and the end is sealed; the other end is fixed to the lower surface of the pool cover 1 without protrusion and a slot 110 is opened at the end. In order to facilitate the understanding of those skilled in the art, some structures are omitted. The pool cover 1 is not installed with an air inlet pipe 1031, an air outlet pipe 1032, a reference electrode 109 and a counter electrode 108. The cross-sectional view along the direction from the first electrode conductor rod 101 to the second electrode conductor rod 102 is as shown in Fig.14 As shown;

[0160] The pool body 2 is an open cylindrical container, the upper opening of the pool body 2 is provided with an internal thread 201, the bottom of the pool cover 1 is provided with a protrusion, the protrusion is provided with an external thread 117, the protrusion is covered with a third annular seal 113, and the pool cover 1 is connected to the pool body 2 by threads;

[0161] The pool body 2 is an open cylindrical container, and a small hole 203 is provided at the bottom of the pool body 2. The quartz wafer 4 is arranged between the pool body 2 and the base 3, and is located directly below the small hole 203. A fourth annular seal 401 is placed above the quartz wafer 4, and a fifth annular seal 402 is placed below the quartz wafer 4.

[0162] The fourth annular seal 401 is clamped between the pool body 2 and the quartz wafer 4;

[0163] The fifth annular seal 402 is clamped between the base 3 and the quartz wafer 4;

[0164] The bottom of the pool body 2 and the upper surface of the base 3 are both provided with two narrow holes 204, and the two narrow holes 204 at the bottom of the pool body 2 are opposite to the two narrow holes 204 on the upper surface of the base 3, forming two channels 202, and the inlet line 403 and the outlet line 404 of the quartz wafer 4 are respectively located in the two channels 202;

[0165] The bottom of the pool body 2 and the upper surface of the base 3 are both provided with a quartz wafer electrode support groove 301 for placing the electrode support 405 of the quartz wafer;

[0166] The base 3 is fixed to the body 2 of the electrochemical quartz crystal microbalance electrolytic cell 9 via a screw 5 .

[0167] In some embodiments, the first annular seal 107, the second annular seal 111, the third annular seal 113, the fourth annular seal 401, the fifth annular seal 402, and the sixth annular seal 114 of the electrochemical quartz crystal microbalance electrolytic cell 9 of any of the above embodiments are independently selected from rubber materials, plastic materials or polyurethane materials.

[0168] In some embodiments, the first annular seal 107, the second annular seal 111, the third annular seal 113, the fourth annular seal 401, the fifth annular seal 402, and the sixth annular seal 114 of the electrochemical quartz crystal microbalance electrolytic cell 9 of any of the above embodiments are independently selected from nitrile rubber, hydrogenated nitrile rubber, silicone rubber, fluorine rubber, fluorosilicone rubber, ethylene propylene diene rubber, polytetrafluoroethylene or polyurethane rubber.

[0169] Example 2: Electrochemical quartz crystal microbalance electrolytic cells of different volumes, weights, and materials

[0170] Combination Figure 3A , Figure 3B , Figure 4 , Figure 6-Figure 8 The electrochemical quartz crystal microbalance electrolytic cell 9 provided by the utility model is specifically described.

[0171] In some embodiments, an electrochemical quartz crystal microbalance electrolytic cell 9 includes: the volume of the electrochemical quartz crystal microbalance electrolytic cell 9 is 30ml-50ml, and the other technical features are the same as those in Example 1.

[0172] In some embodiments, an electrochemical quartz crystal microbalance electrolytic cell 9 includes: the total weight of the cell body 2, quartz crystal 4, base 3 and cell cover 1 is 350g-500g, and the remaining technical features are the same as those in Example 1.

[0173] In some embodiments, an electrochemical quartz crystal microbalance electrolytic cell 9 includes: the cell body 2, the base 3 and the cell cover 1 can be made of polytetrafluoroethylene, and the remaining technical features are the same as those in Example 1.

[0174] In some embodiments, an electrochemical quartz crystal microbalance electrolytic cell 9 includes: the cell body 2, the base 3 and the cell cover 1 are made of acrylic, and the remaining technical features are the same as those in Example 1.

[0175] In some embodiments, an electrochemical quartz crystal microbalance electrolytic cell 9 includes: the cell body 2 is made of acrylic, the base 3 and the cell cover 1 are made of polytetrafluoroethylene, and the remaining technical features are the same as those in Example 1.

[0176] In some embodiments, an electrochemical quartz crystal microbalance electrolytic cell 9 includes: the volume of the electrochemical quartz crystal microbalance electrolytic cell 9 is 30ml-50ml, the total weight of the cell body 2, quartz wafer 4, base 3 and cell cover 1 is 350g-500g, the cell body 2 is transparent acrylic, and the base 3 and cell cover 1 are made of polytetrafluoroethylene.

[0177] In some embodiments, an electrochemical quartz crystal microbalance electrolytic cell 9 includes: the volume of the electrochemical quartz crystal microbalance electrolytic cell 9 is 30ml-50ml, the total weight of the cell body 2, quartz wafer 4, base 3 and cell cover 1 is 350g-500g, the material of the cell body 2, base 3 and cell cover 1 can be polytetrafluoroethylene, and the other technical features are the same as Example 1.

[0178] In some embodiments, an electrochemical quartz crystal microbalance electrolytic cell 9 includes: the volume of the electrochemical quartz crystal microbalance electrolytic cell 9 is 30ml-50ml, the total weight of the cell body 2, quartz wafer 4, base 3 and cell cover 1 is 350g-500g, the material of the cell body 2, base 3 and cell cover 1 is acrylic, and the other technical features are the same as Example 1.

[0179] In some embodiments, an electrochemical quartz crystal microbalance electrolytic cell 9 includes: the volume of the electrochemical quartz crystal microbalance electrolytic cell 9 is 30ml-50ml, the total weight of the cell body 2, quartz wafer 4, base 3 and cell cover 1 is 350g-500g, the cell body 2 is acrylic, the base 3 and the cell cover 1 are made of polytetrafluoroethylene, and the remaining technical features are the same as those in Example 1.

[0180] In some embodiments, an electrochemical quartz crystal microbalance electrolytic cell 9 includes: the volume of the electrochemical quartz crystal microbalance electrolytic cell 9 is 30ml-50ml, the total weight of the cell body 2, quartz wafer 4, base 3 and cell cover 1 is 350g-500g, the cell body 2 is transparent acrylic, and the base 3 and cell cover 1 are made of polytetrafluoroethylene.

[0181] In some embodiments, the first annular seal 107, the second annular seal 111, the third annular seal 113, the fourth annular seal 401, the fifth annular seal 402, and the sixth annular seal 114 of the electrochemical quartz crystal microbalance electrolytic cell 9 of any of the above embodiments are independently selected from rubber materials, plastic materials or polyurethane materials.

[0182] In some embodiments, the first annular seal 107, the second annular seal 111, the third annular seal 113, the fourth annular seal 401, the fifth annular seal 402, and the sixth annular seal 114 of the electrochemical quartz crystal microbalance electrolytic cell 9 of any of the above embodiments are independently selected from nitrile rubber, hydrogenated nitrile rubber, silicone rubber, fluorine rubber, fluorosilicone rubber, ethylene propylene diene rubber, polytetrafluoroethylene or polyurethane rubber.

[0183] Example 3: Electrochemical quartz crystal microbalance electrolytic cell with gas outlet pipe 1032 having flange pipe opening 112

[0184] Combination Figure 3B , Figure 4 , Figure 5A-1 , Figure 5A-2 , Figure 5B-1 , Figure 5B-2 , Figure 6-Figure 8 The electrochemical quartz crystal microbalance electrolytic cell 9 provided by the utility model is specifically described.

[0185] In some embodiments, an electrochemical quartz crystal microbalance electrolytic cell 9 includes: the outlet pipe 1032 adopts the following configuration, which is referred to as configuration a: the outlet pipe 1032 has a flange pipe opening 112; the outlet pipe 1032 passes through the second joint 106 and the double-headed joint 116, the second joint 106 is connected to one end of the double-headed joint 116, and the internal thread of the second through hole 1042 is threadedly matched with the other end of the double-headed joint 116; a second annular seal 111 is padded between the second joint 106 and the double-headed joint 116, When the second joint 106 is spirally connected to the double-headed joint 116, the second annular seal 111 is deformed; the first through hole 1041 is also provided with a sixth annular seal 114, and when the double-headed joint 116 is screwed into the threaded groove of the second through hole 1042, the sixth annular seal 114 is pressed against the diameter-changing port and deformed; except that the arrangement of the air outlet pipe 1032 is different from that of Example 1, the other technical features are the same as those of the electrochemical quartz crystal microbalance electrolytic cell 9 of Example 1 or any one of Example 2, and the cross-sectional view of the cell cover 1 using this arrangement is shown in Figure 5B-1 , Figure 5B-1 The local enlarged view of the C area is shown in Figure 5B-2 The flange pipe opening 112 of the air outlet pipe 1032 of this embodiment is clamped between the sixth annular seal 114 and the double-ended joint 116, which is beneficial to prevent the air outlet pipe 1032 from being rushed out by the internal positive pressure gas, and is beneficial to improve the air tightness of the connection position.

[0186] In some embodiments, an electrochemical quartz crystal microbalance electrolytic cell 9 includes: the outlet pipe 1032 adopts the following configuration, which is referred to as configuration b: the outlet pipe 1032 has a flange pipe opening 112; the outlet pipe 1032 passes through the second joint 106 and does not pass through the double-headed joint 116, the second joint 106 is connected to one end of the double-headed joint 116 thread, and the internal thread of the second through hole 1042 is threadedly matched with the other end of the double-headed joint 116; a second annular seal 11 is padded between the second joint 106 and the double-headed joint 116. 1, when the second joint 106 is screwed with the double-headed joint 116, the second annular seal 111 is deformed; the first through hole 1041 is also provided with a sixth annular seal 114, and when the double-headed joint 116 is screwed into the thread groove of the second through hole 1042, the sixth annular seal 114 is pressed against the diameter reducing port and deformed; except that the arrangement of the air outlet pipe 1032 is different from that of Example 1, the other technical features are the same as those of the electrochemical quartz crystal microbalance electrolytic cell 9 of either Example 1 or Example 2, and the cross-sectional view of the cell cover 1 using this arrangement is shown in Figure 5A-1 , Figure 5A-1 The local enlarged view of area B is shown in Figure 5A-2 The flange pipe opening 112 of the air outlet pipe 1032 of this embodiment is clamped between the third annular seal 111 and the second joint 106, which is conducive to improving the air tightness of the connection position. The flange pipe opening 112 of the air outlet pipe 1032 is clamped between the second annular seal 111 and the second joint 106, which is conducive to preventing the air outlet pipe 1032 from being rushed out by the internal positive pressure gas on the one hand, and on the other hand, it is conducive to improving the air tightness of the connection position.

[0187] In some embodiments, the first annular seal 107, the second annular seal 111, the third annular seal 113, the fourth annular seal 401, the fifth annular seal 402, and the sixth annular seal 114 of the electrochemical quartz crystal microbalance electrolytic cell 9 of any of the above embodiments are independently selected from rubber materials, plastic materials or polyurethane materials.

[0188] In some embodiments, the first annular seal 107, the second annular seal 111, the third annular seal 113, the fourth annular seal 401, the fifth annular seal 402, and the sixth annular seal 114 of the electrochemical quartz crystal microbalance electrolytic cell 9 of any of the above embodiments are independently selected from nitrile rubber, hydrogenated nitrile rubber, silicone rubber, fluororubber, fluorosilicone rubber, EPDM rubber, polytetrafluoroethylene or polyurethane rubber.

[0189] Example 4: Electrochemical quartz crystal microbalance electrolytic cell with different electrode lead rod configurations

[0190] Combination Figure 8 , Fig.12 , Fig.13 and Fig.15 The electrochemical quartz crystal microbalance electrolytic cell 9 provided by the utility model is specifically described.

[0191] In some embodiments, an electrochemical quartz crystal microbalance electrolytic cell 9 includes: the first electrode wire rod 101 and the second electrode wire rod 102 are independently selected from the following settings, referred to as setting ii: one end of the first electrode wire rod 101 or the second electrode wire rod 102 passes through the lower surface of the cell cover 1 and the end is sealed, and the other end is fixed to the upper surface of the cell cover 1 without protruding and a slot 110 is opened at the end. In order to facilitate the understanding of technicians in this field, some structures are omitted. The cell cover 1 is not installed with an air inlet pipe 1031, an air outlet pipe 1032, a reference electrode 109 and a counter electrode 108. The cross-sectional view along the direction from the first electrode wire rod 101 to the second electrode wire rod 102 is as shown in Fig.13 As shown; except that the arrangement of the first electrode lead rod 101 and the second electrode lead rod 102 is different from that in Example 1, the remaining technical features are the same as the electrochemical quartz crystal microbalance electrolytic cell 9 of any one of Example 1, Example 2 or Example 3.

[0192] In some embodiments, an electrochemical quartz crystal microbalance electrolytic cell 9 includes: the first electrode wire rod 101 and the second electrode wire rod 102 are independently selected from the following settings, referred to as settings iii: the first electrode wire rod 101 or the second electrode wire rod 102 passes through the cell cover 1, and extends out from the upper surface and the lower surface of the cell cover 1, at least one of the two ends of the first electrode wire rod 101 is closed, and at least one of the two ends of the second electrode wire rod 102 is closed. In order to facilitate the understanding of those skilled in the art, some structures are omitted. The cell cover 1 is not installed with an air inlet pipe 1031, an air outlet pipe 1032, a reference electrode 109 and a counter electrode 108. The cross-sectional view along the direction from the first electrode wire rod 101 to the second electrode wire rod 102 is as shown in Fig.15 As shown; except that the arrangement of the first electrode lead rod 101 and the second electrode lead rod 102 is different from that in Example 1, the remaining technical features are the same as the electrochemical quartz crystal microbalance electrolytic cell 9 of any one of Example 1, Example 2 or Example 3.

[0193] In some embodiments, an electrochemical quartz crystal microbalance electrolytic cell 9 includes: the first electrode wire rod 101 and the second electrode wire rod 102 are independently selected from the following settings, referred to as setting iv: the first electrode wire rod 101 or the second electrode wire rod 102 is arranged in the pool cover 1, one end of the first electrode wire rod 101 or the second electrode wire rod 102 is fixed to the upper surface of the pool cover 1 without protruding and a slot 110 is opened at the end, and the other end of the first electrode wire rod 101 or the second electrode wire rod 102 is fixed to the surface of the pool cover 1 without protruding and a slot 110 is opened at the end; in order to facilitate the understanding of those skilled in the art, some structures are omitted, and the pool cover 1 is not installed. The cross-sectional view along the direction from the first electrode wire rod 101 to the second electrode wire rod 102 is as shown Fig.12 As shown; except that the arrangement of the first electrode lead rod 101 and the second electrode lead rod 102 is different from that in Example 1, the remaining technical features are the same as the electrochemical quartz crystal microbalance electrolytic cell 9 of any one of Example 1, Example 2 or Example 3.

[0194] In some embodiments, the first annular seal 107, the second annular seal 111, the third annular seal 113, the fourth annular seal 401, the fifth annular seal 402, and the sixth annular seal 114 of the electrochemical quartz crystal microbalance electrolytic cell 9 of any of the above embodiments are independently selected from rubber materials, plastic materials or polyurethane materials.

[0195] In some embodiments, the first annular seal 107, the second annular seal 111, the third annular seal 113, the fourth annular seal 401, the fifth annular seal 402, and the sixth annular seal 114 of the electrochemical quartz crystal microbalance electrolytic cell 9 of any of the above embodiments are independently selected from nitrile rubber, hydrogenated nitrile rubber, silicone rubber, fluorine rubber, fluorosilicone rubber, ethylene propylene diene rubber, polytetrafluoroethylene or polyurethane rubber.

[0196] Example 5: Electrochemical Quartz Crystal Microbalance

[0197] Combined with Fig. 9 The electrochemical quartz crystal microbalance of the utility model is specifically described, which includes an air inlet control valve 1151, an electrochemical quartz crystal microbalance electrolytic cell 9 described in any one of Embodiments 1 to 4, a pressure gauge 6, an air outlet control valve 1152, an electrochemical workstation 7 and an oscillator 8;

[0198] The air inlet control valve 1151 is connected to the air inlet pipe 1031 of the electrochemical quartz crystal microbalance electrolytic cell 9 described in any one of Examples 1 to 4, the pressure gauge 6 and the air outlet control valve 1152 are connected to the air outlet pipe 1032 of the electrochemical quartz crystal microbalance electrolytic cell 9 described in Example 1, the first electrode lead rod 101 and the second electrode lead rod 102 of the electrochemical quartz crystal microbalance electrolytic cell 9 described in any one of Examples 1 to 4 are respectively connected to the electrochemical workstation 7 through wires, and the oscillator 8 is connected to the quartz chip 4 of the electrochemical quartz crystal microbalance electrolytic cell 9 described in any one of Examples 1 to 4.

[0199] In some embodiments, the air inlet control valve 1151 or the air outlet control valve 1152 is selected from a precision flow control valve.

[0200] In some embodiments, the minimum precision unit of the pressure gauge 6 is 1 Pa.

[0201] Example 6: Electrochemical Quartz Crystal Microbalance

[0202] Combined with Fig.10 The electrochemical quartz crystal microbalance of the utility model is specifically described, which includes an air inlet control valve 1151, an electronic gas flow meter 10, an electrochemical quartz crystal microbalance electrolytic cell 9 described in any one of Embodiments 1 to 4, a pressure gauge 6, an air outlet control valve 1152, an electrochemical workstation 7 and an oscillator 8;

[0203] The air intake control valve 1151 and the electronic gas flowmeter 10 are connected to the air intake pipe 1031 of the electrochemical quartz crystal microbalance electrolytic cell 9 described in any one of Examples 1 to 4, the pressure gauge 6 and the air outlet control valve 1152 are connected to the air outlet pipe 1032 of the electrochemical quartz crystal microbalance electrolytic cell 9 described in Example 1, the first electrode lead rod 101 and the second electrode lead rod 102 of the electrochemical quartz crystal microbalance electrolytic cell 9 described in any one of Examples 1 to 4 are respectively connected to the electrochemical workstation 7 through wires, and the oscillator 8 is connected to the quartz chip 4 of the electrochemical quartz crystal microbalance electrolytic cell 9 described in any one of Examples 1 to 4.

[0204] In some embodiments, the air inlet control valve 1151 or the air outlet control valve 1152 is selected from a precision flow control valve.

[0205] In some embodiments, the minimum precision unit of the electronic gas flow meter 10 is 1 ml / min.

[0206] In some embodiments, the minimum precision unit of the pressure gauge 6 is 1 Pa.

[0207] Example 7: Frequency baseline stability comparison test

[0208] A commercial electrochemical quartz crystal microbalance electrolytic cell weighing about 50g and with a volume of 3ml and one of the electrochemical quartz crystal microbalances in Example 6 of the present invention (the electrochemical quartz crystal microbalance electrolytic cell 9 used in the electrochemical quartz crystal microbalance is as follows: the volume of the electrochemical quartz crystal microbalance electrolytic cell 9 is 30ml, the total weight of the cell body 2, quartz crystal wafer 4, base 3 and cell cover 1 is 350g, the material of the cell body 2, base 3 and cell cover 1 is polytetrafluoroethylene, and the remaining technical features are the same as in Example 1; the context is referred to as: electrochemical quartz crystal microbalance electrolytic cell A of the present invention; and the minimum precision unit of the electronic gas flowmeter 10 is 1 ml / min; the minimum precision unit of the pressure gauge 6 is 1 Pa) were used to test the baseline.

[0209] Operation: Baseline test of commercial electrochemical quartz crystal microbalance electrolytic cell: Add 2 ml of 0.1 M sulfuric acid solution to the commercial electrochemical quartz crystal microbalance electrolytic cell, maintain constant temperature and humidity in the room without vibration, and let it stand for 30 minutes to allow the solution to completely stabilize, and then test its frequency change curve over time.

[0210] Baseline test of the sealing state of the electrochemical quartz crystal microbalance electrolytic cell A of the present invention: add 20 ml of 0.1M sulfuric acid solution to the electrochemical quartz crystal microbalance electrolytic cell A of the present invention, screw on the cell cover 1, turn off the air inlet control valve 1151 of the air inlet pipe 1031 and the air outlet control valve 1152 of the air outlet pipe 1032, so that the inside of the electrochemical quartz crystal microbalance electrolytic cell A remains sealed, keep the indoor temperature and humidity constant without vibration, let it stand for 30 minutes to allow the solution to be completely stable, and then test its frequency change curve over time.

[0211] Baseline test of ventilation status of electrochemical quartz crystal microbalance electrolytic cell A of the present invention: add 20 ml of 0.1 M sulfuric acid solution to the electrochemical quartz crystal microbalance electrolytic cell A of the present invention, screw on the cell cover 1, open the air inlet control valve 1151 of the air inlet pipe 1031 and the air outlet control valve 1152 of the air outlet pipe 1032, and allow argon gas to be purged at a flow rate of 10 ml / min to keep the internal air pressure of the electrolytic cell constant (the difference between the maximum and minimum internal air pressures when the internal air pressure fluctuates does not exceed 10 Pa) and maintain a relatively positive pressure compared to the external atmospheric pressure, maintain a constant temperature and humidity indoors without vibration, and let it stand for 30 min to allow the solution to be completely stable, and then test its frequency change curve over time.

[0212] Baseline test of the unsealed state of the electrochemical quartz crystal microbalance electrolytic cell A of the present invention with the cell cover 1 opened: add 20 ml of 0.1M perchloric acid aqueous solution into the electrochemical quartz crystal microbalance electrolytic cell A of the present invention, open the cell cover 1, so that the electrochemical quartz crystal microbalance electrolytic cell A is in an unsealed state, maintain constant temperature and humidity indoors without vibration, let it stand for 30 minutes to allow the solution to be completely stable, and then test its frequency change curve over time.

[0213] result: Figure 1a This is a test chart of the frequency baseline of an electrochemical quartz crystal microbalance using a commercial electrochemical quartz crystal microbalance electrolytic cell in a ventilated state in Example 7; it can be seen that the frequency baseline oscillates violently, with an amplitude exceeding 30 Hz, and cannot be stabilized.

[0214] Figure 1b This is a frequency baseline test diagram of the electrochemical quartz crystal microbalance A of the utility model in a non-ventilated state; during the test time, it is obviously more stable than the baseline obtained by a commercial electrolytic cell, and the fluctuation range is maintained within 1 Hz.

[0215] Figure 1c This is a frequency baseline test diagram of the electrochemical quartz crystal microbalance A of the utility model in the ventilation state. Even under continuous ventilation interference, the frequency baseline is still very stable, with an amplitude of less than 5Hz. Maintaining a stable fundamental frequency when the cell is in the ventilation state is crucial for subsequent measurements. Otherwise, for electrochemical processes with small mass-to-charge changes, the effective signal frequency changes caused by the electrochemical process will be covered by the fundamental frequency noise signal. The above results fully demonstrate that the various improvement measures of the utility model have significantly improved the stability of the EQCM electrolytic cell.

[0216] As shown in FIG1 , compared with a commercial electrochemical quartz crystal microbalance electrolytic cell (see FIG1 a), the test baseline of the electrochemical quartz crystal microbalance using the electrochemical quartz crystal microbalance electrolytic cell A provided by the utility model is extremely stable ( FIG1 b). Even when aeration is performed into the solution at a ventilation rate of 10 ml / min and the baseline is tested simultaneously ( FIG1 c), the baseline also has good stability, and the fundamental frequency variation is less than 5 Hz, which is crucial for obtaining high signal-to-noise ratio data.

[0217] Figure 2 This is the frequency change curve of the electrochemical quartz crystal microbalance electrolytic cell A when it is not sealed. Figure 2 It can be seen that if a high degree of sealing cannot be achieved, the measured data will contain frequency changes caused by gas escape, and this change is complex and cannot be removed by subtraction. The accuracy and reliability of the measured data can only be achieved through a good electrochemical quartz crystal microbalance electrolytic cell design.

[0218] The electrochemical quartz crystal microbalance electrolytic cell 9 of any one of Examples 5-4 is respectively used for the above test, and in a sealed state, it also has an extremely stable test baseline.

[0219] Example 8: Test of the gas tightness of the EQCM electrolytic cell and the mass-to-charge change during the desorption process of the underpotential hydrogen zone

[0220] An electrochemical quartz crystal microbalance of one of the embodiments 6 of the present invention is used. The electrochemical quartz crystal microbalance (the electrochemical quartz crystal microbalance electrolytic cell 9 used in the electrochemical quartz crystal microbalance is: the volume of the electrochemical quartz crystal microbalance electrolytic cell 9 is 30 ml, the total weight of the cell body 2, the quartz wafer 4, the base 3 and the cell cover 1 is 350 g, the material of the cell body 2, the base 3 and the cell cover 1 is polytetrafluoroethylene, and the remaining technical features are the same as in Embodiment 1; the context is referred to as: the electrochemical quartz crystal microbalance electrolytic cell A of the present invention) is used to test the current-voltage change curve (i.e., CV curve) caused by the electrochemical behavior of the underpotential hydrogen zone, the double electric layer zone, and the oxygen zone in the 0-1.4V range on the surface of the polycrystalline Pt electrode, and the frequency Δf in the above process changes with the voltage (i.e., the Δf~V curve) is simultaneously obtained; the charge-frequency change behavior of the oxidation and desorption of underpotential hydrogen in the 0~0.15V range is analyzed in detail to explore the stability of the device of the present invention.

[0221] Operation: Add 20 ml of 0.1 M acid solution (HClO4 or H2SO4 solution) or 0.1 M alkaline aqueous solution (KOH or NaOH solution) to the electrochemical quartz crystal microbalance electrolytic cell A of the utility model, keep the room constant temperature and humidity without vibration, use argon gas to purge the electrolyte at a flow rate of 15 ml / min for 30 minutes to remove all oxygen in the solution, then stop ventilation and keep the electrochemical quartz crystal microbalance electrolytic cell A sealed and close the inlet control valve 1151 of the inlet pipe 1031 and the outlet control valve 1152 of the outlet pipe 1032. After stabilization for 20 minutes, obtain the CV curve and Δf~V curve in the range of 0-1.4 V; and focus on analyzing the underpotential hydrogen oxidation and desorption interval (0-0.15V, corresponding to the Volmer step of the hydrogen oxidation process), based on the iV curve of CV, obtain the integrated charge Q in this interval, and draw a graph of Δf versus Q to obtain the law of mass-to-charge ratio variation with voltage in this process.

[0222] result:

[0223] Fig.11Figures a1-a2 in the middle are the CV curves (solid line) corresponding to the change in charge on the electrode surface during the electrochemical process in the range of 0-1.6V on the surface of polycrystalline Pt under acidic conditions measured by EQCM in the literature (Electrochemistry Communications, 2000, 2, Page692–696) and the frequency-voltage curve (dashed line Δf~V) caused by the mass change. The CV curve has an overall significant dip in the double-layer region (the red horizontal line in the figure corresponds to the current zero point), indicating that there is a significant oxygen reduction current, indicating that the airtightness is poor; the Δf~V curve in the underpotential hydrogen region is obviously not closed, and the Δf~V measured in sulfuric acid and perchloric acid solutions are very different, indicating that the QCM fundamental frequency amplitude is large and there are stability problems, resulting in poor frequency data quality.

[0224] Fig.11 Figures b1 and c1 in the middle are typical CV curves obtained by using the electrochemical quartz crystal microbalance electrolytic cell A of the utility model in Example 8 to perform CV tests in perchloric acid or sulfuric acid aqueous solution. It can be seen that due to the improvement in airtightness, the double electric layer sinking phenomenon of the CV curve obtained by the utility model device is significantly improved compared with the data in the literature; corresponding Fig.11 The Δf~V curve of b2 or c2 in the figure can be perfectly closed, and both b2 and c2 solutions are acidic, and their Δf~V curve trends are relatively similar, which indirectly shows that the data has good repeatability, and further shows that the fundamental frequency stability of the electrode is significantly improved.

[0225] Fig.11 Figure d1 or e1 in the middle is a typical CV curve obtained by using the electrochemical quartz crystal microbalance electrolytic cell A of the utility model to perform CV test in NaOH or KOH aqueous solution in Example 8. It can be seen that the double electric layer sinking phenomenon is significantly improved compared with the data in the literature; the corresponding Fig.11 The Δf~V curves of d2 or e2 in the middle figure can be perfectly closed, and both d2 and e2 solutions are alkaline, and their Δf~V curve trends are relatively similar, which indirectly shows that the data has good repeatability, and further indicates that the fundamental frequency stability of the electrode is significantly improved.

[0226] More importantly, Fig.11 Figures b3 / c3 / d3 / e3 in the middle are the Volmer steps of the hydrogen oxidation process *H à* + H under the corresponding conditions for the underpotential hydrogen oxidation desorption process (0-0.15V vs RHE range). + + e -), based on the current integration of the CV curve, after obtaining the integrated current Q (mC) of the process, the frequency change Δf of this interval was further plotted with the change of the integrated charge Q. It can be seen that although the change of Δf in this interval is only within 10 Hz regardless of acid or alkali, the results given by the device of the utility model show that there are significant differences in the mass-to-charge ratio Δf~Q of the electrode surface in different pH values ​​and different acid or alkali types, and this difference indicates that the mechanism of the Volmer step is different under different pH values. On the whole, under acidity, whether in sulfuric acid or perchloric acid, the mass-to-charge ratio (df / dQ) in this interval tends to be linear, while under alkalinity, whether in potassium hydroxide or sodium hydroxide, the mass-to-charge change ratio in this interval is close to zero. These high-quality mass-to-charge change data can provide effective guarantee for subsequent more quantitative analysis such as calculating the MPE value (mass accumulated for transfer of per mole electrons), which is of great significance for studying the pH effect of hydrogen-to-electricity conversion process. And the similarity of data of different acid or alkali types also proves the repeatability of the data of this device.

[0227] The above comparison results fully demonstrate that the utility model can synchronously track the mass-charge changes on the electrode surface. By comparing the Δf~V curve and Δf~Q curve measured by the utility model under acidic and alkaline conditions, it can be seen that even for an electrochemical reaction process such as underpotential hydrogen adsorption and desorption with a frequency change of only a few Hz, the EQCM of the utility model can effectively distinguish the differences in surface mass and charge changes between the two. In addition, there are obvious differences in the mass-charge change curves measured by the utility model device at different pH values ​​(in acid vs. in alkali), and this difference is regular, which proves that the signal-to-noise ratio of the utility model device is effectively improved, which is something that current literature or commercial electrolytic cells cannot do.

[0228] In summary, by improving the air tightness of the cell body, controlling the air pressure amplitude in the electrolytic cell at the Pa level, increasing the capacity and weight, and other series of measures, the utility model successfully stabilizes the fundamental frequency amplitude of the QCM electrode within 5 Hz, greatly reducing the noise Δf0 during the ventilation process, thereby significantly improving the signal-to-noise ratio of the instrument frequency (Δf / Δf0), so that it can effectively detect the mass-to-charge changes in processes such as underpotential hydrogen oxidation and desorption where the effective signal is extremely weak (Δf is only a few Hz).

[0229] Example 9: CO-stripping test

[0230] A CV test was performed using one of the electrochemical quartz crystal microbalances of Example 6 of the present invention (the electrochemical quartz crystal microbalance electrolytic cell 9 used in the electrochemical quartz crystal microbalance is as follows: the volume of the electrochemical quartz crystal microbalance electrolytic cell 9 is 30 ml, the total weight of the cell body 2, the quartz crystal wafer 4, the base 3 and the cell cover 1 is 350 g, the material of the cell body 2, the base 3 and the cell cover 1 is polytetrafluoroethylene, and the remaining technical features are the same as those of Example 1; the context is referred to as: the electrochemical quartz crystal microbalance electrolytic cell A of the present invention) .

[0231] Operation: Add 20 ml of 0.1 M H2SO4 solution or 0.1 M KOH solution to the electrochemical quartz crystal microbalance electrolytic cell A of the utility model, keep the room constant temperature and humidity without vibration, purge the electrolyte with argon gas at a flow rate of 15 ml / min for 30 min to remove all oxygen in the solution, pass CO gas into the solution for more than 20 min to saturate it before testing, the ventilation rate is 5 ml / min, and then apply a constant voltage of 0.1 V (vs. RHE) for 10 min, while continuing to pass CO; then keep the voltage unchanged, pass Ar gas for 20 min, the ventilation rate is 10 ml / min, wait for the system to stand for 10 min, collect CV curves, obtain the current change with voltage information of the CO-stripping process, and synchronously collect the frequency change curve.

[0232] Results: See Fig.16 .

[0233] The CO stripping process is the oxidation and desorption process of CO molecules adsorbed on the Pt surface. This process is a common electrochemical method for evaluating the OH adsorption strength on the Pt surface. The difference in CO desorption peaks at different pH values ​​can reflect different electrochemical processes on the surface. Fig.16 It can be seen that the electrochemical quartz crystal microbalance using the electrochemical quartz crystal microbalance electrolytic cell A provided by the utility model can effectively track the information of the change in the amount and frequency of the CO oxidation process on the surface of polycrystalline Pt at different pH values. The df / dQ curves at different pH values ​​are significantly different. By fitting the curve to calculate the MPE value, it can help analyze the difference in the adsorption strength of CO and OH- at different pH values. This example further proves the effectiveness of the utility model device in studying the surface interface of various electrochemical processes.

[0234] The method of the utility model has been described through the preferred embodiment, and relevant personnel can obviously modify or appropriately change and combine the methods and applications described herein within the content, spirit and scope of the utility model to implement and apply the technology of the utility model. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters. It is particularly important to point out that all similar replacements and modifications are obvious to those skilled in the art, and they are all considered to be included in the utility model.

Claims

1. An electrochemical quartz crystal microbalance electrolytic cell (9), characterized in that: include, A pool cover (1), wherein a first electrode conductor rod (101) and a second electrode conductor rod (102) are embedded in one side of the pool cover (1), and the pool cover (1) is also detachably provided with an air pipe (103), wherein the air pipe (103) is used to input or output gas to the pool body (2). One end of the pool body (2) is detachably connected to the pool cover (1), and one end of the pool body (2) away from the pool cover (1) is detachably connected to the base (3), and a quartz wafer (4) is clamped between the base (3) and the pool body (2).

2. The electrochemical quartz crystal microbalance electrolytic cell (9) according to claim 1, characterized in that: The air pipe (103) comprises an air inlet pipe (1031) and an air outlet pipe (1032), wherein the air inlet pipe (1031) and the air outlet pipe (1032) are provided with a control valve (115) for controlling the flow of gas, and when the control valve (115) is closed, the electrochemical quartz crystal microbalance electrolytic cell (9) forms a sealed space.

3. The electrochemical quartz crystal microbalance electrolytic cell (9) according to claim 2, characterized in that: The pool cover (1) is provided with a plurality of air flow channels (104), wherein the air flow channels (104) include a first through hole (1041) and a second through hole (1042) connected by a reducing port, and the first through hole (1041) and the second through hole (1042) are both provided with internal threads. The air inlet pipe (1031) passes through the first joint (105), and the internal thread of the first through hole (1041) cooperates with the external thread provided on the first joint (105). The air outlet pipe (1032) is connected to the second joint (106), the second joint (106) is connected to one end of the double-ended joint (116) thread, and the internal thread of the second through hole (1042) is matched with the other end thread of the double-ended joint (116).

4. The electrochemical quartz crystal microbalance electrolytic cell (9) according to claim 3, characterized in that: A first annular seal (107) is also placed in the first through hole (1041); when the first joint (105) is screwed into the thread groove of the first through hole (1041), the first annular seal (107) is pressed against the reducing port and deformed; and / or, The first electrode conductor rod (101) and the second electrode conductor rod (102) are integrally embedded in the pool cover (1); and / or the first electrode conductor rod (101) is detachably connected to the counter electrode (108) or the reference electrode (109) by means of a plug-in connection; and / or the second electrode conductor rod (102) is detachably connected to the counter electrode (108) or the reference electrode (109) by means of a plug-in connection.

5. The electrochemical quartz crystal microbalance electrolytic cell (9) according to claim 4, characterized in that: The first electrode lead rod (101) and the second electrode lead rod (102) are independently selected from the following settings: (i) one end of the first electrode conductor rod (101) or the second electrode conductor rod (102) passes through the upper surface of the pool cover (1) and the end of the part passing through is sealed; the other end is fixed to the lower surface of the pool cover (1) without protruding and a slot (110) is opened at this end; (ii) one end of the first electrode conductor rod (101) or the second electrode conductor rod (102) passes through the lower surface of the pool cover (1) and the end of the passing portion is sealed, and the other end is fixed to the upper surface of the pool cover (1) without protruding and a slot (110) is opened at the end; (iii) the first electrode conductor rod (101) or the second electrode conductor rod (102) passes through the pool cover (1) and extends out from both the upper surface and the lower surface of the pool cover (1), at least one of the two ends of the first electrode conductor rod (101) is closed, and at least one of the two ends of the second electrode conductor rod (102) is closed; or (iv) The first electrode conductor rod (101) or the second electrode conductor rod (102) is arranged in the pool cover (1), one end of the first electrode conductor rod (101) or the second electrode conductor rod (102) is fixed to the upper surface of the pool cover (1) without protruding and a slot (110) is opened at the end, and the other end of the first electrode conductor rod (101) or the second electrode conductor rod (102) is fixed to the surface of the pool cover (1) without protruding and a slot (110) is opened at the end.

6. The electrochemical quartz crystal microbalance electrolytic cell (9) according to claim 3, characterized in that: The air inlet pipe (1031) passes through the first joint (105) and the air flow channel (104) and penetrates into the cell body (2) of the electrochemical quartz crystal microbalance electrolytic cell (9); and / or, The depth of the air inlet pipe (1031) extending into the pool body (2) is adjustable; and / or, A second annular seal (111) is provided between the second joint (106) and the double-ended joint (116).

7. The electrochemical quartz crystal microbalance electrolytic cell (9) according to claim 3, characterized in that: The air outlet pipe (1032) has a flange pipe opening (112).

8. The electrochemical quartz crystal microbalance electrolytic cell (9) according to claim 1, characterized in that: The pool body (2) is an open cylindrical container, the upper opening of the pool body (2) is provided with an internal thread (201), the bottom of the pool cover (1) is provided with a protrusion, the protrusion is provided with an external thread (117), the protrusion is covered with a third annular sealing member (113), and the pool cover (1) is connected to the pool body (2) via threads; and / or The pool body (2) is an open cylindrical container, the bottom of the pool body (2) has a small hole (203), the quartz wafer (4) is arranged between the pool body (2) and the base (3), and is located directly below the small hole (203), a fourth annular sealing member (401) is placed above the quartz wafer (4), and a fifth annular sealing member (402) is placed below the quartz wafer (4); and / or The bottom of the pool body (2) and the upper surface of the base (3) are both provided with two narrow holes (204), and the inlet wire (403) and outlet wire (404) of the quartz wafer (4) are respectively located in the two narrow holes (204); and / or The bottom of the pool body (2) and the upper surface of the base (3) are both provided with a quartz wafer electrode support groove (301) for placing the electrode support (405) of the quartz wafer; and / or The two narrow holes (204) at the bottom of the pool body (2) are opposite to the two narrow holes (204) on the upper surface of the base (3), forming two channels (202), and the inlet line (403) and outlet line (404) of the quartz wafer (4) are respectively located in the two channels (202); and / or The base (3) and the body (2) of the electrochemical quartz crystal microbalance electrolytic cell (9) are fixed via a screw (5).

9. The electrochemical quartz crystal microbalance electrolytic cell (9) according to claim 1, characterized in that: The volume of the electrochemical quartz crystal microbalance electrolytic cell (9) is 30ml-50ml; and / or The total weight of the pool body (2), the quartz wafer (4), the base (3) and the pool cover (1) is 350 g to 500 g; and / or The pool body (2), the base (3) and the pool cover (1) are made of polytetrafluoroethylene or acrylic; or the pool body (2) is made of acrylic, and the base (3) and the pool cover (1) are made of polytetrafluoroethylene.

10. An electrochemical quartz crystal microbalance, characterized in that: It comprises an air inlet control valve (1151), an electrochemical quartz crystal microbalance electrolytic cell (9) as described in any one of claims 1 to 8, a pressure gauge (6), an air outlet control valve (1152), an electrochemical workstation (7) and an oscillator (8).

11. The electrochemical quartz crystal microbalance according to claim 10, characterized in that: The electrochemical quartz crystal microbalance also includes an electronic gas flow meter (10).

12. The electrochemical quartz crystal microbalance according to claim 10, characterized in that: The air inlet control valve (1151) is connected to the air inlet pipe (1031) of the electrochemical quartz crystal microbalance electrolytic cell (9) described in any one of claims 1 to 8, the pressure gauge (6) and the air outlet control valve (1152) are connected to the air outlet pipe (1032) of the electrochemical quartz crystal microbalance electrolytic cell (9) described in any one of claims 1 to 8, the first electrode lead rod (101) and the second electrode lead rod (102) of the electrochemical quartz crystal microbalance electrolytic cell (9) described in any one of claims 1 to 8 are respectively connected to the electrochemical workstation (7) through wires, and the oscillator (8) is connected to the quartz chip (4) of the electrochemical quartz crystal microbalance electrolytic cell (9) described in any one of claims 1 to 8.

13. The electrochemical quartz crystal microbalance according to claim 10, characterized in that: The air inlet control valve (1151) and the electronic gas flowmeter (10) are connected to the air inlet pipe (1031) of the electrochemical quartz crystal microbalance electrolytic cell (9) described in any one of claims 1 to 8, the pressure gauge (6) and the air outlet control valve (1152) are connected to the air outlet pipe (1032) of the electrochemical quartz crystal microbalance electrolytic cell (9) described in any one of claims 1 to 8, the first electrode lead rod (101) and the second electrode lead rod (102) of the electrochemical quartz crystal microbalance electrolytic cell (9) described in any one of claims 1 to 8 are respectively connected to the electrochemical workstation (7) through wires, and the oscillator (8) is connected to the quartz chip (4) of the electrochemical quartz crystal microbalance electrolytic cell (9) described in any one of claims 1 to 8.

14. The electrochemical quartz crystal microbalance according to claim 11, characterized in that: The minimum precision unit of the electronic gas flow meter (10) is 1 ml / min.

15. The electrochemical quartz crystal microbalance according to claim 10, characterized in that: The minimum precision unit of the pressure gauge (6) is 1 Pa.

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