JPH01182748A - Method and apparatus for measuring electrochemical characteristic of gas - Google Patents

Abstract

PURPOSE:To clarify the mechanisms of oxidation reduction and reaction, by supplying a gas to be measured, on the side of a working electrode with respect to a solid state electrolyte, supplying electric power, which is controlled at a constant voltage or a constant current, to the solid state electrolyte, and measuring the electrochemical characteristics of the gas. CONSTITUTION:In a detector 10, a solid state electrolyte 11 is arranged at the center of a reacting tubes. The reacting tubes are double tubes comprising an outer tube 12 made of alumina and the like and an inner tube 13 made of quartz glass and the like. Electrodes 16 are applied on both sides of the solid state electrolyte 11. The electrode 16, which is applied on one side, is connected to a potentiogalvanostat through a working electrode 17. The electrode 16, which is applied on the other side, is connected to a potentiogalvanostat through a counter electrode 18. A gas to be measured is supplied to the side of the working electrode 17 with respect to the solid state electrolyte 11. Power, which is controlled at a constant voltage or a constant current, is supplied to the solid state electrolyte 11. The electrochemical characteristics, which are generated by the supply of the power, are measured. The electrochemical characteristics of the solid state electrolyte itself are subtracted from the measured data in an operating part, and the electrochemical characteristics of the gas to be measured are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for measuring electrochemical properties of gases, such as cyclic voltammetry, Tafel lines, and complex impedance.

[Conventional Description] Various electrochemical properties are commonly measured to measure physical and chemical phenomena that involve electron movement at the interface between an electrode and a solution. This measurement of electrochemical properties involves applying a potential to a solution-based electrode, and from the relationship between the potential at that time and the current per hour, analytical information and basic information regarding electrochemical active species in the solution 1. For example, redox and reaction mechanisms. Electrolytes are essential for its measurement.

[Problems to be solved] On the other hand, even with methane gas and various water-insoluble organic substances,
In order to elucidate redox and reaction mechanisms at high temperatures, it is necessary to measure various electrochemical properties such as current-potential curves, Tafel lines, and complex impedance.

However, since methane gas and various water-insoluble organic substances are gaseous at high temperatures, no electrolyte exists, and it has not been possible to measure various electrochemical properties. For this reason, there has been a desire for a method and apparatus capable of measuring the electrochemical properties of this type of gas.

The present invention was made in view of the above-mentioned circumstances, and by utilizing a solid electrolyte, the electrochemical properties of gases can be improved.
For example, the purpose of the present invention is to provide a method and apparatus that can measure current-potential curves, Terfel lines, and complex impedance, and thereby clarify gas oxidation-reduction and reaction mechanisms.

Similarly to electrolytic solutions, solid electrolytes that exhibit electrical conduction through ions are widely used as sensors and memory elements, but they are known to change due to differences in gas atmospheres and to analyze the results to investigate gas oxidation-reduction and reactions. It has never been used to elucidate the mechanism.

[Means for Solving Problems] As a result of intensive studies to achieve the above object, the inventor of the present invention has devised a method for supplying a gas to be measured into a solid electrolyte detector and applying constant voltage or constant current controlled power to the solid electrolyte. supply,
Measure the electrochemical property data generated by supplying this constant voltage or constant current controlled power, and subtract the electrochemical property data of the solid electrolyte itself from the above measurement data to obtain the electrochemical properties of the gas to be measured. More specifically, the gas to be measured is supplied to the working electrode side of the solid electrolyte, and the solid electrolyte is supplied with constant voltage or constant current controlled power in accordance with the triangular wave potential,
Change the above-mentioned supplied power, measure the current value or voltage value for the applied potential or supplied current, and subtract the baseline data from the above-mentioned measurement data to obtain the current-potential curve of the gas to be measured. 2, a method for measuring cuportammetry, and a solid electrolyte for carrying out the method, and
A detector capable of supplying a gas to be measured to the working electrode side of this solid electrolyte, a function generator that generates a triangular wave potential, and a constant voltage or constant current controlled electric power to the solid electrolyte in accordance with the waveform from the function generator. a potentiogalvanostat that supplies the voltage and measures the current value or voltage value with respect to the applied potential or supplied current; and a storage unit that stores the data as wave data in which the potential is taken in the X axis and the current is taken in the Y axis. , by obtaining a gas cyclic voltammetry measuring device, which is equipped with an arithmetic unit that subtracts baseline data from the wave data to obtain a current-potential curve of a gas to be measured.

In addition, the gas to be measured is supplied to the working electrode side of the solid electrolyte, and constant voltage or constant current controlled power is supplied to the solid electrolyte to measure the current value or electric i value that changes depending on the reaction of the gas to be measured. Measure each potential or each current to obtain a polarization curve, and during the above measurement, find the IR low resistance, subtract the IR resistance from the above polarization curve, and obtain the Terfel line based on the polarization curve of the gas to be measured. A Terfel line measuring method, a detector equipped with a solid electrolyte and capable of supplying a gas to be measured to the working electrode side of the solid electrolyte, and a funxion generator for setting a potential, for carrying out this method; Constant voltage or constant current controlled power is supplied to the solid electrolyte based on the potential from this function generator, and the current or voltage value that changes due to the reaction of the sample gas is measured for each potential or each current. , and includes a potentiogalvanostat that determines the IR low resistance during the measurement, and a calculation unit that subtracts the IR low resistance from the measurement data to determine the polarization curve of the gas to be measured, and creates a Terfel line based on this data. Furthermore, by obtaining a Terfel line measurement device for a gas with a temperature of 100 nm, it is possible to supply the gas to be measured to the working electrode side of the solid electrolyte, and to supply electric power controlled at a constant voltage or constant current in accordance with the waveform of the AC potential to the solid electrolyte. Then, the distorted potential or current distortion is measured and each impedance component is calculated.

A gas complex impedance measurement method for determining the complex impedance of a gas to be measured by subtracting the impedance of the solid electrolyte itself from the impedance component determined above, and a solid electrolyte for carrying out this method, and
A detector capable of supplying the gas to be measured to the working electrode side of the solid electrolyte, and a detector capable of supplying a constant voltage or constant current controlled power to the solid electrolyte according to the waveform of the AC potential, and a distorted potential or current distortion. a potentiogalvanostat that measures the above, a frequency characteristic analyzer that generates the AC potential or current and calculates the components of each impedance based on the measurement data from the potentiogalvanostat, and the components of each impedance obtained by the above calculations. The present inventors have discovered that the above object can be achieved by obtaining a gas complex impedance measurement device that is equipped with a calculation unit that calculates the complex impedance of the gas to be measured by subtracting the impedance of the solid electrolyte itself, and has arrived at the present invention. .

The present invention will be explained in detail below.

First, an apparatus for measuring electrochemical properties according to the present invention will be explained.

Figure 1 shows a block diagram of a general electrochemical property measuring device. In the figure, 1 is a function generator, 2 is a potentiogalvanostat (constant voltage constant current generator), and 3 is a digital memory. 4 is an oscilloscope, 4 is a frequency characteristic analyzer (for example, FRA spectrum analyzer), 5 is a calculation section consisting of a personal computer, etc., and 10 is a detector.

The function generator 1 is used to program operations such as changing or sweeping the electric potential, and outputs an arbitrary function to the potentiogalvanostat 2. As the waveform, based on waveforms such as a triangular wave, a pulse wave, and a sine curve, a combination wave of these waveforms can also be output. Furthermore, in order to synchronize with the potentiogalvanostat 2, it is equipped with a communication function for transmitting data to a computer.

The potentiogalvanostat 2 has a function to precisely control voltage or current, and also has an external function input function to detect arbitrary waveforms such as triangular waves and pulse waves sent from the function generator 1.
Apply to O.

It is also capable of precise measurement of voltage and current in real time, and is also equipped with a communication function to transfer measured data.

The digital memory oscilloscope 3 reproduces the data measured by the potentiogalvanostat 2 on the oscilloscope in real time, and simultaneously stores the waveform in a wave memory (not shown). Note that only the storage unit can be a separate dedicated device. It also has communication functions to control data storage and transfer measured data.

The frequency characteristic analyzer 4 measures each component of impedance over a wide range of frequencies.

The impedance components that can be measured are impedance, inductance, resistance, capacitance, reactance, admittance, susceptance, conductance, or a composite value thereof. In addition, the frequency is 0.0001Hz to 100MHz, practically O
, IO2-100KH2.

The detector 10 has a solid electrolyte 11 arranged in the center of a reaction tube, and each reaction tube is constructed as a double tube with an outer tube 12 made of alumina or the like and an inner tube 13 made of quartz glass or the like. A reaction tube on one side of the solid electrolyte 11 is provided with a sample (to-be-measured) gas supply port 14a and a discharge port 14b, and a reaction tube on the other side is provided with a reference gas supply port 15a and a discharge port 15b. It is.

Electrodes 16 are coated on both sides of the solid electrolyte 11,
The electrode 16 applied on the - side is connected to the working electrode 17.
The electrodes 16 applied on the other side are each connected to the potentiometer galvanostat 2 by a counter electrode 18. Further, 19 is a reference electrode that determines the standard of the potential applied to the solid electrolyte 11.

The shape of the reaction tube in the detector 10 may be of various types, such as a tubular shape, a flat plate shape, a thin film shape, etc., in addition to the above-mentioned double tube type.

The reason why the solid electrolyte 11 is used in the present invention is as follows.

In other words, in the liquid phase, electrolytes with high redox potential such as Li2SO4 can be used, but in the gas phase, there is no electrolyte itself, and there are almost no electrolytes that are stable at high temperatures.Therefore, solid electrolytes that are stable even at high temperatures are used. is used.

The selection of this solid electrolyte must be made in accordance with the characteristics of the reaction. For example, in the case of an oxidation reaction, oxygen ion conductors are preferable. Oxide must be selected.

Table 1 summarizes the relationship between temperature and conductivity of the solid electrolyte.

[Left below] Table 1 K・Lo・5.2Fe2030.8Zn01.8X10
-2 (300℃) Cd2° Cd-13” -yh
Mit 1.7X1G-' (300℃
) This single crystal In addition to the solid electrolytes shown in this table, basically any ionic conductor can be used to measure electrochemical properties in the gas phase.

On the other hand, as the electrode 16 applied to the solid electrolyte 11, a normal paste may be used, but a metal or oxide powder may be ground and made into an acetone suspension and applied.

Typical electrode preparation methods are listed below, but are not limited thereto.

B. The same volume of the IN sodium hydroxide aqueous solution was added to the silver nitrate aqueous solution of the #i electrode IN to form a silver hydroxide precipitate. After sufficiently ripening the precipitate, it was filtered and washed with distilled water until the pH reached 7. After drying in an oven at 80° C. overnight, a silver oxide powder was obtained.

The prepared silver oxide powder was ground in a mortar to form an acetone suspension. This was applied to the solid electrolyte. This solid electrolyte was fired at 400° C. for 1 hour to decompose silver oxide into silver. This operation was repeated several times, and it was confirmed with a tester that the conductivity was sufficient, and a silver electrode was used.

mouth, platinum electrode platinum oxide or ammonium chloroplatinate in the air,
It was baked at 500°C for 3 hours. This powder was made into a butyl acetate or acetone suspension. This was applied to the solid electrolyte. This solid electrolyte was fired at 1000° C. for 1 hour to decompose platinum oxide into platinum. This operation was repeated several times, and sufficient conductivity was confirmed using a tester, and a platinum electrode was used.

C. Perovskite oxide electrode powder mixture The perovskite oxide electrode was synthesized by a powder mixing method. The raw material powder is a special grade A-site metal oxide reagent with a purity of 99.9% or higher and a purity of 99.9%.
The above B-site metal oxide or carbonate special grade reagent was used. Before weighing, the sample bottle containing the reagent is dried overnight in a vacuum dryer (120° C., 5 Torr or less) and quickly measured using an analytical balance.

Each reagent was weighed so that the total weight was 5 g, and then placed in an agate planetary ball mill (mill pot 80 cc, ball 15 Φ
x 10 pieces). As a solvent, use acetone that has been dried on a molecular sheep for at least one night. Mix for 30 minutes at a revolution speed of 40 Or, p, m.

This suspension is air-dried in a fume hood. Furthermore, this powder is classified using a 400-egh sieve to obtain a mixed powder for firing.

This mixed powder for firing is pressed into a press machine at 100 kg/c2
Temporarily mold with pressure. The shape is a disc-shaped pellet of 17Φ-0.5t. Put this into an alumina crucible,
Temperature raising program (heating up to 1400 °C at 2 °C/sin, during which time 50
Calcinate at 0°C and 900°C (maintained at constant temperature for 1 hour).

One of the fired pellets will be subjected to XRD analysis to identify its crystal system and compound; the remaining pellets will be analyzed.

Grind in an alumina mortar. Grind this finely in an agate mortar. Then, put it into an agate planetary ball mill (80cc mill pot, 15ΦXIG balls). As a solvent, use the dry acetone used during mixing. Grind for 60 minutes at a revolution of 500 r, p, m. This suspension is naturally dried in a fume hood. Furthermore, this powder is classified using a 400 mesh sieve to obtain an oxide powder for electrodes. This oxide powder for electrodes was applied to a solid electrolyte. This solid electrolyte was fired at 1000° C. for 1 hour, this operation was repeated several times, and sufficient conductivity was confirmed using a tester, and a perovskite-type oxide electrode was obtained.

The following are promising oxide electrodes:

Nacl type Tio, Vo, Euo+-x etc. 5pin@l type LiTi20n, Fe3O4 etc. perovsk
ite-Re0i fiR@03, MxRe03
, C4VQ3.5rVO3, LaCOO3 etc. coru
ndum type V2O3, Ti2 (h etc. rutile -MeO2 type (Magneli phase included) VO2
, MeO2, a-Ref2Ju02. 2N IF a type La2NiOa, Nd2NiOn etc. to Ti3O5 etc. Pyrochlore type T12Rh207. Pb2Ru20z-x, Bi2R
A general method for measuring electrochemical properties using the above-mentioned devices such as U207-x, T1203-x, MXV20S-X, etc. is as follows.

■ Sample gas is supplied to one side of the solid electrolyte 11 (working electrode 17 side) from the supply port 14a of the detector IO, and reference gas is supplied to the other side of the solid electrolyte 11 (counter electrode 18 side) from the supply port 15a. do.

■The solid electrolyte 1 of the detector 10 receives electric power controlled at constant voltage or constant current by the potentiogalvanostat 2.
1 to transmit a potential to the sample gas.

■ Constant voltage or constant current controlled power is supplied to the solid electrolyte 1.
Measure the current and potential characteristics when supplied to 1. At this time, it is possible to store the data in a memory at high speed, transfer the data to the calculation section 5, and reproduce the data transferred from the calculation section 5 as a screen on the digital memory oscilloscope 3.

■Compare and calculate the measured characteristic data with the characteristic data obtained when a vacuum is not supplied or when an inert gas is supplied to obtain the electrochemical characteristics of the sample gas only.

Next, a case where the present invention is applied to specific measurements (cyclic voltammetry measurement, Turfel line measurement, and complex impedance measurement) will be described.

Cyclic voltammetry measurement Cyclic voltammetry uses a constant potential control method to sweep the potential at a constant rate, and from the current changes at that time, it can be used to measure the redox potential, reaction mechanism, rate-determining step, reaction order of elementary reactions, etc. It is a means to find out.

Cyclic voltammetry is originally a method developed in the liquid phase, and is a method for measuring the electrochemical redox behavior of reactants adsorbed on electrodes. In this case, a supporting electrolyte is always required in the solution, and an electrolyte such as Li2SO4 that has high conductivity and does not decompose at a low potential is used. This is a measurement method that utilizes the fact that by making the charge transfer rate due to ion movement sufficiently faster than the diffusion rate of the reactant, only the reactant adsorbed on the electrode surface undergoes redox due to the electric potential.

The measuring device has the configuration shown in FIG. 3, and a wide range generator is used as the function generator l. In liquid phase cyclic voltammetry measurements, this is 1 usually 0. It was sufficient to measure in the range of IH2~10=H2, but in the case of gas, the diffusion coefficient is 10 compared to liquid.
4 times (1G' cs2 /sec ~108 c intestine2/
5ea) is also large, therefore, the time during which it is adsorbed to the electrode is short, and it is necessary to cycle at a correspondingly high speed.Usually, a device with a range of about 10KHz = 10-'H2 is used.

Further, the digital memory oscilloscope 3 is equipped with a wave memory. this is.

Due to its high speed, it cannot be measured with a normal XY plotter, so it is necessary to store the potential and current in memory, and if it is equipped with memory, baseline correction and function processing can be easily performed. be.

The measurement is carried out as follows: the microcomputer 5 sends a signal to the function generator 1 to generate a triangular wave as shown in FIG.

This triangular wave output signal is sent to the potentiogalvanostat 2 to generate a constant voltage triangular wave. The apex potential of the triangular wave at this time is adjusted according to each reaction. Normally, it is -2,0
Measurement is performed at approximately V~+2.0v.

In this way, the triangular wave potential generated by the constant potential control method using the potentiogalvanostat 2 has the characteristic that it does not fluctuate even if the current consumption rate changes rapidly.In this point, it is different from the triangular wave generated from the function generator l. different. Now.

Since this triangular wave potential is applied to a reference that does not vary, the reference electrode 19 is necessary even when the solid electrolyte 11 is used. Therefore, the part in contact with the atmosphere was used as the reference electrode 19. The potential of the working electrode 17 is controlled using this reference electrode 19 as a reference.

In this way, when a triangular wave potential is applied to the solid electrolyte 11, a current flows in response. When this current is plotted against the applied potential, a current-potential curve (cyclic voltamgram) is obtained. An example of the current-potential curve is shown in FIG.

This data is further displayed on the oscilloscope 3 in real time and stored using the memory wave function. This data is transferred to the microcomputer 5 and combined with other measurement data to create secondary data.For example, when performing cyclic voltammetry measurements, the influence of the atmosphere always intervenes. The result of subtracting the data in is the current-potential curve of the gas that is originally intended to be measured. Such data processing is only possible with the memory wave function.

The above method can be summarized as follows.

■ Supply sample gas and reference gas to the detector 10.

■ Generate a triangular wave potential with the function generator 1 and output it to the potentiogalvanostat 2.

(2) The potentiogalvanostat 2 generates a constant voltage in accordance with the waveform from the function generator 1, and applies this to the solid electrolyte 11 of the detector 10.

(4) The potentiostat 2 detects a current value corresponding to the applied potential, and outputs this to the digital memory oscilloscope 3 as data.

[Co., Ltd.] The above data is captured using the digital memory oscilloscope 3 with potential on the X axis and current on the Y axis.
Store this in wave memory (on the screen, the results of cyclic voltammetry are displayed according to the data)
.

■ The data stored in the digital memory oscilloscope 3 is transferred to the personal computer 5, where it is compared with the data obtained when vacuum or inert gas is used (baseline data), and the cyclic portammetry of the sample gas is calculated. Obtain the result (transfer this result to the digital memory oscilloscope 3 and display it on one screen).

Note that similar measurements can also be made by supplying constant current-controlled power to the solid electrolyte 11 of the detector 10.

The Muni-25-Tarfel line measurement is a method for estimating the exchange current density under charge transfer rate-limiting conditions. Also, by this measurement, the transfer coefficient α is determined. The principle of this measurement is as follows.

Let us now assume that the first reaction is charge transfer rate-determining and is not affected by mass transfer. At this time, the exchange current density is Butler
It is expressed by the r-Volmer equation (1).

(1) By shifting the balance of this equation and increasing the constant potential η, the first term or the second term can be ignored. Therefore, it can be approximated as shown in the following equation.

When η>O...(2) When η<O...Qψ...(2°) The graph plotting loglil against η is
It is a terfel plot. The transfer coefficient α and the exchange current density io are determined from the slope and intercept of this straight line.

In the present invention, measurement is performed as follows using an apparatus as shown in FIG.

A voltage is applied to the solid electrolyte 11 of the detector 10 by the potentiogalvanostat 2. The standard at this time is the reference electrode 19 stabilized in the atmosphere. For example, the range of the potential to be applied is -1,0V to +1. Ov and 10
Measurements were taken every 0 mV. - Even if a constant potential is applied, when measuring the current value, it gradually decays as a function of time. This attenuation function is stored in a wave memory, and the microcomputer 5 simulates the attenuation function to calculate an asymptote. Let the value of this asymptote be the equilibrium current value i at that potential. Repeat this measurement and la for η
Plot g-th 1 and find the transfer coefficient α and exchange current density io from its slope and intercept.

On the other hand, a galvanostatic pulse is introduced during this measurement, and the IR resistance is calculated by the current interrupter method. Here, the current interrupter method is a method in which a reaction is carried out with a constant current, the voltage is instantaneously interrupted, and chemical reaction resistance and charge transfer resistance are measured separately based on the waveform of the voltage at that time.

In addition to the method described above, there is a method of superimposing alternating current as a method for obtaining low IR resistance. In other words, the alternating current of IKH-100KH is superimposed by the frequency characteristic analyzer, stored in the wave memory, and then transferred to the microcomputer. In order to minimize the influence of the superimposed alternating current, the potential of the alternating current is set to 1 to 1. The range is 15 mV. After transferring to the microcomputer, frequency characteristic analysis is performed. In the 0-frequency analysis, the amplitude and phase shift are calculated from the sin curve of the superimposed potential, and the obtained wave is divided into gin θ and 90
゜Considering it as a composite function of cos θ with a phase shift, perform component analysis.Calculate the actual value for each component, find resistance and reactance, and find IR low resistance.

IR low resistance calculation using this AC superimposition method is performed in a FRAR spectrum analyzer.

I found it as above! The Tafel line can be obtained by subtracting the RR anti-portion from the above measurement data to obtain a polarization curve, and organizing this data using the formula η=ab Ioglil.

The above method can be summarized as follows.

■ Supply sample gas and reference gas to the detector 10.

■ Set the potential with function generator 1 and output it to potentiogalvanostat 2.

(2) A voltage made constant by the potentiogalvanostat 2 is applied to the solid electrolyte 11 of the reactor 10.

(2) By applying a potential, the current value that changes due to the reaction of the sample gas is measured for each potential to obtain a polarization curve.

- During the above measurement, find the IR low resistance using the current interrupter method or the AC superimposition method.

(2) In the personal computer 5, a Tafel line is created based on the polarization curve □ line subtracted from the above polarization curve data on the IR resistor. The Tafel line obtained in this way becomes the Tafel line of only the sample gas.

Note that similar measurements can also be made by supplying constant current-controlled power to the solid electrolyte 11 of the detector 10.

Double impedance measurement The measurement principle for this measurement is shown below, where impedance = Z, reactance = x, resistance = R.
Then, Z = R + X i...Conflict... (1) However, ko is an imaginary unit. Z, R, and X are physical property values as a whole, and the impedance of each is further divided into three fine parts, as shown in the schematic diagram of FIG. First, the bulk internal resistance Rh of one particle itself,
Next, there are three parts: the grain boundary resistance R9 of the contact interface between particles, the same capacitance C1, and finally the polarization resistance Rr generated at the interface with the electrode and the capacitance cr. These impedances are calculated using the equivalent circuit shown in FIG.

A combination of these elements is measured as the overall impedance Z.

The combined impedance is calculated from the equivalent circuit shown in Figure 8.

・Write... (2) Transform this to find the relationship between the real part and the imaginary part of the impedance component.

In general, the grain boundary resistance is many orders of magnitude smaller than the surface polarization, so in the high zero frequency region there is the relationship ωRtCt > 1 > ωR,C, . . . -(3).

1 <<ωRrCr, so after this assumption, rearrange equation (3) and get (R-Rh-Rq/2)2+ X2- (1/4) R
92... Meeting e... (4) Therefore, center Rb '' Rq / 2, radius (1/2)
It becomes a circle of Rq.

In the low frequency region, 1 >> ωRgG, so solving in the same way gives (R-Rb-Rq-Rr/2)2+ X2- (1/4
) Rt2...@ (5) The center is Rh '' Rq◆Rr / 2 , and the radius is (1/2) Rr, so the horizontal axis is resistance (R) and the vertical axis is reactance (X) Figure 9 is obtained by taking and plotting, and it can be seen that the intercept with the horizontal axis is the sum of the resistance components.

From this, R1+, Rg, and Rr of each component can be determined. This plot is called a complex impedance plot, also known as a Cole-Cole plot. In this way, the resistance of ceramics can be divided and measured for each element.

A circle is drawn from the measurement results as follows. First, examine the increase or decrease in actance from the measurement results, and find the point where the increase or decrease is reversed.

Normally, this point is a loss, so the measurement points were divided into groups based on the sixth point, which can be easily found. For each group, the center and radius of the optimal circle were determined by substituting it into the circle equation. Finally, draw a circle! The resistance value of each component was determined from the point of contact with the lx axis.

Up to this point, the method has been the same as the conventional method, and this measurement is usually performed in a reversible system to obtain knowledge regarding the sintering of the solid electrolyte.

The present invention is based on the above-mentioned measurement principle and measures the complex impedance of a gas, which has never been done before.The measurement is carried out in the following manner using an apparatus as shown in FIG. 11.

A voltage is applied from the potentiogalvanostat 2 to the solid electrolyte 11 of the d detector 10, and the resistance and actance at that time are measured.
000℃, measuring voltage 1.00QV to L, frequency 5H2tts 13MH2;l: TE. Thereafter, through data processing, the complex impedance of only the sample gas can be determined by subtracting the complex impedance due to the solid electrolyte itself.

The increase in the resistance value of the reactance portion is a phenomenon that occurs due to the presence of a capacitance component specific to the reactant. By actively capturing this phenomenon, we can learn about the state of reactants and reaction intermediates. This feature can be obtained by measuring the impedance characteristics and then plotting reactance against frequency. By measuring this, known as a Bode diagram of reactance, while applying a bias potential, it becomes possible to evaluate the characteristics of substances in each oxidation state.

Compared to the Cole-Cole plot, the only thing that changes in the reactance Bode plot is the reactance, so
The capacitance component of the gas to be measured can be clearly understood. Therefore, it is suitable for observing gas redox.

Furthermore, in order to further minimize the thermal electromotive force due to the Seebeck effect, the flow rate of oxygen or oxygen-containing gas is
It is preferable to set it to 1017 layers iII+ or less.

The above method can be summarized as follows.

■ Supply sample gas and reference gas to the detector 10.

■ Generate an AC potential with the FRA spectrum analyzer 4 and output it to the potentiogalvanostat 2.

(2) A constant voltage is applied to the solid electrolyte 11 from the potentiogalvanostat 2 in accordance with the waveform of the AC potential.

(2) Measure the distortion of the current with respect to the input potential (sample gas is polarized by the potential, and therefore the current is distorted), and based on this measurement data, the FRA spectrum analyzer 4 calculates each impedance component.

(2) Each impedance component determined by calculation is transferred to the personal computer 5, where the impedance of the solid electrolyte 11 itself (for example, when an inert gas is used) is subtracted. This determines the complex impedance of only the sample gas.

Note that, as described above, the reactance Bode diagram may also be obtained, so the complex impedance measurement in the present invention includes the measurement of the reactance Bode diagram.

Similar measurements can also be made by supplying constant current controlled power to the solid electrolyte 11 of the detector IO.

It goes without saying that the method and apparatus for measuring electrochemical properties of solids according to the present invention can also be applied to measurements of electrochemical properties of gases other than the above-mentioned cyclic voltammetry, Tafel line, and complex impedance measurements.

[Hereinafter, blank spaces] [Examples] Examples of cyclic voltammetry measurement, Tafel line measurement, and complex impedance measurement to which the present invention is applied will be described below.

The symbols for the solid electrolyte and the gas to be measured that will be used in the description of the examples are as follows.

Solid electrolyte; YSZ: Yttria-stabilized zirconia oxide ion conductor SOY: Strontium ceria acid proton conductor KBA: Potassium-β'-alumina potassium ion conductor Measuring gas; IPA: 2-Propertool AC Nia7ton B7: Benzene cHA Nidiclohexane! IH^: n-hexane BrOH: Phenol Examples - List implementation Reaction Solid electrode Measured frequency example
Temperature Electrolyte Gas 1
400℃ YSZ Aq
Summer PA o, toz240
0℃SCY Aq 1PA O, IH23400
℃KBA Aq IPA O,IHz4 5
50℃ 〃〃〃〃 5 350℃ 〃〃〃〃 651O℃YSZ Aq ACO, 1Hz7510
℃SOY Aq ACO, IH2851O℃YSZ
Aq B2 0. IH2951O℃SCY A
q Bz O, IHzlo 510℃YSZ
Ag cHA 0. IHzll '510℃SCY
Aq cHA Q, IHz12 510℃YS
Z Aq BzOHO, IHz13 510℃
SCY Todoroki BzOHO,
IHz14 510℃YSZ Aq nHA 0
．． IHz15 510℃SCY Aq nHA
0. IHz16 400℃YSZ Pt IPA
O, IHz Example 1 0 Cyclic voltammetry measurements were performed using YSZ as the solid electrolyte and Aq as the electrode. The measurement temperature was 400°C. The atmosphere on the working electrode side was argon gas, which was supplied at a gas flow rate of 5 ml/sin. The reference electrode was exposed to the atmosphere, and a constant electrochemical potential was maintained at all times. The counter electrode was provided with a dry air atmosphere and a gas flow of 1130 l/in. IPA was supplied as a gas to be measured to the working electrode at a liquid flow rate of 1.8 ml/hr. The measurement potential range is -2.5V to ÷2.5V, and the frequency is 0. It was set as In2. The measurement potential sweep was started from Ov in the positive direction.

The current-potential curve at this time was as shown in A and 1 shown in FIG.

0 The current-potential curve of the solid electrolyte itself was obtained under the same conditions as above except that the gas to be measured was not supplied (ffil1
Figure 0.1), this becomes the baseline data.

0 Current-potential curve (a,
1), find the current-potential curve by subtracting the current-potential curve (0, 1) when the gas to be measured is not supplied.
This is the current-potential curve of only the gas to be measured, as shown in the figure.

Example 2 0 Cyclic voltammetry measurements were performed using YSZ as the solid electrolyte and A9 as the electrode. The measurement temperature was 400°C. The atmosphere on the working electrode side was argon gas, which was supplied at a gas flow rate of 5 ml/win. The reference electrode was exposed to the atmosphere, and a constant electrochemical potential was maintained at all times. The counter electrode was supplied with a dry hydrogen atmosphere at a gas flow rate of 30 m1/sin. IPA was supplied as a gas to be measured to the working electrode at a liquid flow rate of 1.8 ml/hr. The zero constant potential range was −1.5 V to +1.5 V, and the frequency was 0.1 Hz. This gave a current-potential curve.

0 A current-potential curve of the solid electrolyte itself was obtained under the same conditions as above except that the gas to be measured was not supplied. This becomes the baseline data.

0 From the current-potential curve when the gas to be measured is supplied,
A current-potential curve obtained by subtracting the current-potential curve obtained when the gas to be measured is not supplied is shown in FIG. 13. This is the current-potential curve for only the gas to be measured.

becomes.

Example 3 0 Cyclic voltammetry measurements were performed using potassium β-A12Q3 as the solid electrolyte and Ag as the electrode. The measurement temperature was 400°C. The atmosphere on the working electrode side is argon gas, and the gas flow rate is 5ml.
/sin. The reference electrode was exposed to the atmosphere, and a constant electrochemical potential was maintained at all times. The counter electrode is in a dry air atmosphere with a gas flow rate of 3.
It was supplied at 0ml/win. IPA was supplied as a gas to be measured to the working electrode at a liquid flow rate of 1.8 ml/hr. The measurement potential range was -2.5V to +2.5V, and the frequency was 0.1Hz. The measurement potential sweep was started from Ov in the positive direction. This gave a current-potential curve.

0 A current-potential curve of the solid electrolyte itself was obtained under the same conditions as above except that the gas to be measured was not supplied. This becomes the baseline data.

The current-potential curve obtained by subtracting the current-potential curve when the gas to be measured is not supplied from the current-potential curve when the gas to be measured is supplied is shown in Figure 14, and this is the current for only the gas to be measured. It becomes a potential curve.

Example 4 0 Cyclic voltammetry measurements were performed using potassium β-A12Q3 as the solid electrolyte and A as the electrode. The measurement temperature was 550°C. The atmosphere on the working electrode side was argon gas, which was supplied at a gas flow rate of 5.1/win. The reference electrode was exposed to the atmosphere, and a constant electrochemical potential was maintained at all times. The counter electrode was supplied with a dry air atmosphere at a gas flow rate of 301 in. IPA was supplied as a gas to be measured to the working electrode at a liquid flow rate of 1.8 ml/hr. The measurement potential range was -2.5V to -2.5V, and the frequency was 0.1H. The measurement potential sweep was started from Ov in the positive direction. This gave a current-potential curve.

0 A current-potential curve of the solid electrolyte itself was obtained under the same conditions as above except that the gas to be measured was not supplied. This becomes the baseline data.

0 From the current-potential curve when the gas to be measured is supplied,
A current-potential curve obtained by subtracting the current-potential curve obtained when the gas to be measured is not supplied is obtained and shown in FIG. 15, which is the current-potential curve for only the gas to be measured.

Example 5 0 Cyclic voltammetry measurements were performed using potassium No. β-A1203 as the solid electrolyte and A as the electrode. The measurement temperature was 350°C. The atmosphere on the working electrode side is argon gas, and the gas flow rate is 5+s.
Supplied in l/peng. The reference electrode was exposed to the atmosphere, and a constant electrochemical potential was maintained at all times. The counter electrode was supplied with a dry air atmosphere at a gas flow rate of 30 ml/in. IPA as the gas to be measured
was supplied to the working electrode side at a liquid flow rate of 1.8+sl/by. Measurement potential range t±-2.5V ~÷2.5V
, the frequency was 0.1Hz. The sweep of the measured potential is
I started in the positive direction from Ov. This gave a current-potential curve.

0 A current-potential curve of the solid electrolyte itself was obtained under the same conditions as above except that the gas to be measured was not supplied. This becomes the baseline data.

0 From the current-potential curve when the gas to be measured is supplied,
A current-potential curve obtained by subtracting the current-potential curve obtained when the gas to be measured is not supplied is obtained and shown in FIG. 16, which is the current-potential curve for only the gas to be measured.

Example 6 0 Cyclic voltammetry measurements were performed using YJZ as the solid electrolyte and A9 as the electrode. The measurement temperature was 510°C. The atmosphere on the working electrode side was argon gas, which was supplied at a gas flow rate of 5 ml/win. The reference electrode was exposed to the atmosphere, and a constant electrochemical potential was maintained at all times. The counter electrode was supplied with a dry air atmosphere at a gas flow rate of 30 m1/sin. AC was supplied as the gas to be measured to the working electrode side at a liquid flow rate i of 8 ml/hr. The measurement potential range is -
2.5v~+2.5V.

The frequency was set to 0.1)1z. The sweep of the measured potential is
I started in the positive direction from Ov. This gave a current-potential curve.

0 Using YSz as the solid electrolyte, A as the electrode.

Cyclic voltammetry measurements were performed using

The measurement temperature was 510°C. The atmosphere on the working electrode side was argon gas, which was supplied at a gas flow rate of 5 ml/1 n. The reference electrode was exposed to the atmosphere, and a constant electrochemical potential was maintained at all times. The counter electrode was supplied with a dry air atmosphere at a gas flow rate of 30 m1/sin. AC was supplied as a gas to be measured to the working electrode side at a liquid flow rate of 1.8 ml/hr. The measurement potential range is -
2.5v~◆2.5V.

The frequency is 0. IH, thereby obtaining a current-potential curve (baseline data) of the solid electrolyte itself.

0 From the current-potential curve when the gas to be measured is supplied,
A current-potential curve obtained by subtracting the current-potential curve obtained when the gas to be measured is not supplied is obtained and shown in FIG. 17, which is the current-potential curve for only the gas to be measured.

Example 7 0 SOY was used as the solid electrolyte, and A was used as the electrode.

Cyclic voltammetry measurements were carried out using The 1rA constant temperature was 510°C. The atmosphere on the working electrode side was argon gas, which was supplied at a gas flow rate of 5 ml/sin. The atmosphere of the reference electrode is open to the atmosphere.
A constant electrochemical potential was maintained at all times. The counter electrode was in a dry air atmosphere and was supplied with a gas flow rate of 30 ml/in. AC was supplied as a gas to be measured to the working electrode side at a liquid flow rate of 1.8 ml/hr. The measurement potential range is -2.5v to +2.5v, and the frequency is 0. It was set to IH2. The measurement potential sweep was started from Ov in the positive direction. This gave a current-potential curve.

0 The current was -
Potential surface! ! (Baseline data) was obtained.

The current-potential curve obtained by subtracting the current-potential curve when the gas to be measured is not supplied is obtained from the current-potential curve when the gas to be measured is supplied, and this is shown in Figure 18. It becomes a potential curve.

Example 80 Cyclic voltammetry measurements were performed using YSZ as the solid electrolyte and A9 as the electrode. The measurement temperature was 510°C. The atmosphere on the working electrode side was argon gas, which was supplied at a gas flow rate of 5 ml/sin. The reference electrode was exposed to the atmosphere, and a constant electrochemical potential was maintained at all times. The counter electrode was supplied with a dry air atmosphere at a gas flow rate of 30i+I/win. Bz was supplied as a gas to be measured to the working electrode side at a liquid flow rate of 1.8 ml/hr. The measurement potential range was -2.5v to ÷2.5v, and the frequency was 0.1Hz.

Sweep of measurement potential.

I started in the positive direction from Ov. This gave a current-potential curve.

0 A current-potential curve (baseline data) was obtained under the same conditions as in Example 6 when the gas to be measured was not supplied.

0 From the current-potential curve when the gas to be measured is supplied,
A current-potential curve obtained by subtracting the current-potential curve obtained when the gas to be measured is not supplied is obtained and shown in FIG. 19. This is the current-potential curve for only the gas to be measured.

Example 9 0 SOY was used as the solid electrolyte, and A was used as the electrode.

Cyclic voltammetry measurements were performed using

The measurement temperature was 510°C. The atmosphere on the working electrode side was argon gas, which was supplied at a gas flow rate of 5 ml/win. The reference electrode was exposed to the atmosphere, and a constant electrochemical potential was maintained at all times. The counter electrode was supplied with a dry hydrogen atmosphere at a gas flow rate of 30 m1/sin. Hz was supplied as the gas to be measured to the working electrode side at a liquid flow rate of 1.8 ml/hr. The measurement potential range was -2.5v to ÷2.5v, and the frequency was 0.1Hz.

The II4 constant potential sweep was started from Ov in the positive direction. This gave a current-potential curve.

0 The current was -
Potential curves (baseline data) were obtained.

0 From the current-potential curve when the gas to be measured is supplied,
A current-potential curve obtained by subtracting the current-potential curve obtained when the gas to be measured is not supplied is obtained and is shown in FIG. 20, which is the current-potential curve for only the gas to be measured.

Example 100 Cyclic voltammetry measurements were performed using YSZ as the solid electrolyte and A9 as the electrode. The measurement temperature was 510°C. The atmosphere on the working electrode side was argon gas, which was supplied at a gas flow rate of 5 ml/inch. The reference electrode was exposed to the atmosphere, and a constant electrochemical potential was maintained at all times. The counter electrode was supplied with a dry air atmosphere at a gas flow rate of 30 m1/sin. As a gas to be measured, cHA was supplied to the working electrode side at a liquid flow rate of 1.8 ml/hr. The constant potential range was -2.5 V to +2.5 V, and the frequency was 0.1 Hz. The measurement potential sweep was started from Ov in the positive direction.

Thereby, a current-potential curve was obtained.

0 A current-potential curve (baseline data) was obtained under the same conditions as in Example 6 when the gas to be measured was not supplied.

0 From the current-potential curve when the gas to be measured is supplied,
A current-potential curve obtained by subtracting the current-potential curve obtained when the gas to be measured is not supplied is obtained and shown in FIG. 21. This is the current-potential curve for only the gas to be measured.

Example 110 Cyclic voltammetry measurements were performed using SCY as the solid electrolyte and At as the electrode. The measurement temperature was 510°C. The atmosphere on the working electrode side was argon gas, which was supplied at a gas flow rate of 5 ml/sin. The reference electrode was exposed to the atmosphere, and a constant electrochemical potential was maintained at all times. The counter electrode was supplied with a dry hydrogen atmosphere at a gas flow rate of 30 m1/win. As a gas to be measured, cHA was supplied to the working electrode side at a liquid flow rate of 1.8 ml/hr. The measurement potential range was -2.5V to ◆2.5V, and the frequency was 0.1Hz. The measurement potential sweep was started from Ov in the positive direction.

Thereby, a current-potential curve was obtained.

A current-potential curve (baseline data) was obtained under the same conditions as in Example B when no gas to be measured was supplied, except that SCY was used as the O solid electrolyte.

0 From the current-potential curve when the gas to be measured is supplied,
A current-potential curve obtained by subtracting the current-potential curve obtained when the gas to be measured is not supplied is obtained and shown in FIG. 22, which is the current-potential curve for only the gas to be measured.

Example 12 0 Cyclic voltammetry was performed using YSZ as the solid electrolyte and A@ as the electrode. The measurement temperature was 510°C. The atmosphere on the working electrode side was argon gas, which was supplied at a gas flow rate of 5 ml/win. The reference electrode was exposed to the atmosphere, and a constant electrochemical potential was maintained at all times. The counter electrode is in a dry air atmosphere with a gas flow rate of 3111 ml/sin.
It was supplied by B zOH was supplied as the gas to be measured to the working electrode side at a liquid flow rate of 1.8 s+I/hr. The measurement potential range is -2.5V to medium 2.5V, and the frequency is 0.1
It was marked as old. The measurement potential sweep was started from Ov in the positive direction.

Thereby, a current-potential curve was obtained.

0 Current-potential surface under the same conditions as when no gas to be measured is supplied in Example 6! l (baseline data) was obtained.

0 From the current-potential curve when the gas to be measured is supplied,
A current-potential curve obtained by subtracting the current-potential curve obtained when the gas to be measured is not supplied is obtained and shown in FIG. 23. This is the current-potential curve for only the gas to be measured.

Example 130 Cyclic voltammetry measurements were performed using SCY as the solid electrolyte and A9 as the electrode. The measurement temperature was 510°C. The atmosphere on the working electrode side was argon gas, which was supplied at a gas flow rate of 5 ml/sin. The reference electrode was exposed to the atmosphere, and a constant electrochemical potential was maintained at all times. The counter electrode was supplied with a dry hydrogen atmosphere at a gas flow rate of 30 m1/sin. BzOH was supplied as a gas to be measured to the working electrode side at a liquid flow rate of 1.8 ml/hr. The measurement potential range was -2.5V to ÷2.5V, and the frequency was 0.1Hz. The IIA constant potential sweep was started from Ov in the positive direction.

Thereby, a current-potential curve was obtained.

0 The current was -
Potential curves (baseline data) were obtained.

0 From the current-potential curve when the gas to be measured is supplied,
A current-potential curve obtained by subtracting the current-potential curve obtained when the gas to be measured is not supplied is obtained and is shown in FIG. 24, which is the current-potential curve for only the gas to be measured.

Example 14 0 Using YSZ as the solid electrolyte, A as the electrode.

Cyclic voltammetry measurements were performed using

The measurement temperature was 510°C. The atmosphere on the working electrode side was argon gas, which was supplied at a gas flow rate of 5 ml/sin. The reference electrode was exposed to the atmosphere, and a constant electrochemical potential was maintained at all times. The counter electrode was supplied with a dry air atmosphere at a gas flow rate of 30 m1/jin. As a gas to be measured, nHA was supplied to the working electrode side at a liquid flow rate of 1.8 ml/hr. The measurement potential range was -2.5V to +2.5V, and the frequency was 0.1Hz. The measurement potential sweep was started with Ov also in the positive direction.

Thereby, a current-potential curve was obtained.

0 in Example 6. A current-potential curve (baseline data) was obtained under the same conditions as when no gas to be measured was supplied.

0 From the current-potential curve when the gas to be measured is supplied,
A current-potential curve obtained by subtracting the current-potential curve obtained when the gas to be measured is not supplied is obtained and shown in FIG. 25. This is the current-potential curve for only the gas to be measured.

Example 150 Cyclic voltammetry measurements were performed using SCY as the solid electrolyte and A9 as the electrode. The measurement temperature was 510°C. The atmosphere on the working electrode side was argon gas, which was supplied at a gas flow rate of 51/in.

The reference electrode was exposed to the atmosphere, and a constant electrochemical potential was maintained at all times. A dry hydrogen atmosphere was supplied to the counter electrode at a gas flow rate of 3111 ml/sin. nHA was supplied as a gas to be measured to the working electrode side at a liquid flow rate of 1.8@l/hr. The measurement potential range was -2.5V to -2.5V, and the frequencies were o and tnz. Measured potential +7) The sweep was started from Ov in the positive direction.

Thereby, a current-potential curve was obtained.

0 The current was -
Potential curves (baseline data) were obtained.

0 From the current-potential curve when the gas to be measured is supplied,
A current-potential curve obtained by subtracting the current-potential curve obtained when the gas to be measured is not supplied is obtained and shown in FIG. 26. This is the current-potential curve for only the gas to be measured.

Example 160 Cyclic voltammetry measurements were performed using YSZ as the solid electrolyte and PT as the electrode. The measurement temperature was 510°C. The atmosphere on the working electrode side was argon gas, which was supplied at a gas flow rate of 5 ml/win. The reference electrode was exposed to the atmosphere, and a constant electrochemical potential was maintained at all times. The counter electrode was supplied with a dry air atmosphere at a gas flow rate of 30 m1/sin. IPA was supplied as the gas to be measured to the working electrode side at a liquid flow rate of 1.8 ml/hr. The measurement potential range is -2.5V to ÷2.5V, and the frequency is 0. The sweep of the measured potential was started from Ov in the positive direction.

Thereby, a current-potential curve was obtained.

0 A current-potential curve of the solid electrolyte itself was obtained under the same conditions as above except that the gas to be measured was not supplied. This becomes the baseline data.

0 From the current-potential curve when the gas to be measured is supplied,
A current-potential curve obtained by subtracting the current-potential curve obtained when the gas to be measured is not supplied is obtained and shown in FIG. 27. This is the current-potential curve for only the gas to be measured.

Note that the current-potential curve during supply of the gas to be measured in Example 1 changes as shown in FIG. 28 when the frequency is changed.

Examples of Tafel line measurement (17 to 19) Examples - List example Temperature Electrolyte 17500℃ YSZ a, IPAts, s
oo℃YSZ A,, AC19500℃YSZ
Aq BzOH, CH30H Example 17 YSZ was used as the solid electrolyte. The electrode is Aq,
The reaction temperature is 500°C. The atmosphere on the working electrode side was argon gas, which was supplied at a gas flow rate of 51/in. The reference electrode was exposed to the atmosphere, and a constant electrochemical potential was maintained at all times. The counter electrode was supplied with a dry air atmosphere at a gas flow rate of 130 ml/win. IPA was supplied as a gas to be measured to the working electrode at a liquid flow rate of 1.8 ml/hr. Potential range t*-t
, ov' ~+1. Measurements were made at OV and 100 mA. Even if a constant potential is applied, when the current value is measured, it gradually attenuates as a function of time.

This attenuation function is stored in a wave memory, and a microcomputer performs a simulation of the attenuation function to calculate an asymptote. The value of this asymptote is taken as the equilibrium current value at that potential. Repeat this measurement and logl for η
il is plotted, and the transfer coefficient α and exchange current density to are determined from its slope and intercept.

On the other hand, the polarization is calculated by subtracting the IR resistance part using the current interrupt method or AC superimposition method, which is performed by introducing a galvanostatic pulse in the middle of this measurement.
In addition to determining the polarization curves of the node and cathode, the Terfel line is determined based on this data (Second 9th
figure).

In addition, in the current interrupter method! In R resistance measurement, to reduce noise and increase S/N ratio,
Measurement was performed using pulses using a pulse generator instead of direct current.

In the experiment, measurement was performed using a HC-110 pulse generator manufactured by Hokuto Denko Co., Ltd. Measurements are performed with constant current pulses, usually 100 layers A, pulse interval 2 layers S, pulse width 0.1
Measurements were made in mg (corresponding to IOKH2). The measurement conditions (temperature, flow rate, etc.) were the same as the reaction conditions unless there were any particular problems. A measurement example is shown in FIG. 32.

When the voltage is turned off, the part that changes suddenly is the solid internal movement resistance, which is Rb+R in the Cole-Cole plot above.
, corresponds to . After that, the point where the curve falls is the voltage corresponding to the chemical reaction and charge discharge. This is due to the above Rt + Ct + Cq and resistance due to chemical reaction (for example, C
1 (adsorption of 4).

For specific division, a straight line was drawn that coincided with the initial rise, and the point where the measurement curve departed from this straight line was defined as the dividing point.

Through such measurements, the resistance value of the chemically reactive component was calculated.

Example 18 A Terfel wire was obtained under the same conditions as Example 17 except that the gas to be measured supplied to the working electrode side was AC.
Figure 0).

Example 19 The gases to be measured supplied to the working electrode side were B, OH and CH30H! Example 17 except that a mixed solution of :l was used.
The Tafel line was obtained under the same conditions as (Fig. 31).

[Left below] Complex impedance measurement - Examples (20-21) Examples -
List implementation Reaction Solid electrode Measured gas example
Temperature Electrolyte 20 500℃ YSZ A9 1PA
21 500℃ YSZ A q BzO
H, CH30H Example 200 VSZ was used as the solid electrolyte. The electrode is A
The 8 reaction temperature defined as 9 is 500°C. The atmosphere on the working electrode side is argon gas, and the gas flow rate is 5.1/si.
Supplied at n. The reference electrode was surrounded by the atmosphere, and a constant electrochemical potential was maintained at all times.

The counter electrode has a dry air atmosphere with a gas flow rate of 30 m1.
/win was supplied. IPA was supplied as a gas to be measured to the working electrode at a liquid flow rate of 1.8 ml/hr.

The complex impedance measurement was performed using a YHP4192 impedance measurement device at an applied voltage AC of 1.0 OOV, and the zero frequency was measured at 30 points at logarithmic intervals in the range of 5H2 to 20KH. From this result, complex impedance was determined and reactance was plotted against the logarithm of one frequency.

0 Measurement was performed under the same conditions as above except that the gas to be measured was not supplied. From this result, reactance was plotted against the logarithm of one frequency.

o'$ The complex impedance and reactance were determined by subtracting the results when the gas to be measured was not supplied from the results when the gas to be measured was supplied. Plot or draw in terms of actance or show the Bode plot of actance (
Figure 33 c, l).

Example 21 YSZ was used as the O solid electrolyte. The electrode is A9
The zero reaction temperature was 500°C. The atmosphere on the working electrode side is argon gas, and the gas flow rate is 5ml/win.
It was supplied by The reference electrode was exposed to the atmosphere, and a constant electrochemical potential was maintained at all times. The counter electrode is in a dry air atmosphere with a gas flow rate of 30 m11.
It was supplied at 1n. 820H and Cl30 as gases to be measured
A 1:l mixed solution of H was applied to the working electrode side at a liquid flow rate of 1.
It was supplied at a rate of 8 ml/hr.

The complex impedance measurement was performed using a YHP4192 impedance measuring device with an applied voltage of AC 1,000 V. The zero frequency was measured at 30 points at logarithmic intervals in the range of 5 Hz to 20 KHz. From this result, reactance was plotted against the logarithm of one frequency.

0 Complex impedance and reactance were determined by subtracting the results when the gas to be measured was not supplied from the results when the gas to be measured was supplied. A Bode diagram of reactance plotted or drawn by actance is shown (Fig. 33 C, 2).

[Effects of the Invention] As described above, according to the present invention, it is possible to perform electrochemical properties of gases, such as cyclic voltammetry measurements, Tafel line measurements, and complex impedance measurements, which have never been done before. This makes it possible to elucidate the redox and reaction mechanisms of gases.

Furthermore, since a solid electrolyte that can withstand high temperatures can be used, it is also possible to measure the electrochemical properties of gases at high temperatures.

[Brief Description of the Drawings] Fig. 1 is a general block diagram of the device of the present invention, Fig. 2 is a detailed diagram of the detector, and Fig. 3 is a block diagram of the device for cyclic voltammetry measurement of the present invention. , FIG. 4 is a waveform diagram of the potential generated by the function generator, FIG. 5 is a current-potential curve, FIG. 6 is a block diagram of the apparatus for measuring the Tafel line according to the present invention, FIG. 7 is a schematic diagram of impedance, and FIG. 8 9 is an equivalent circuit, FIG. 9 is a Cole-Cole plot diagram, FIG. 10 is a block diagram of an apparatus for measuring complex impedance of the present invention, and FIGS. 11 to 28 are current-potential curves in each embodiment of cyclic voltammetry measurement. , 29th
Figures 31 to 31 are Tafel lines in each example of Tafel line measurement, Figure 32 is an explanatory diagram of IR resistance measurement using the current interrack method, and Figure 33 is a Bode diagram created by plotting reactance in complex impedance measurement. shows. ! =Function generator 2: Potentiogalvanostat 3: Digital memory oscilloscope 4: Frequency characteristic analyzer 5: Arithmetic unit (microcomputer) lO: Detector 11: Solid electrolyte

Claims (7)

[Claims] (1) By supplying the gas to be measured to the working electrode side of the solid electrolyte, supplying constant voltage or constant current controlled power to the solid electrolyte, and supplying this constant voltage or constant current controlled power, A method for measuring electrochemical properties of a gas, characterized in that the electrochemical properties of a gas to be measured are obtained by measuring the generated electrochemical properties and subtracting the electrochemical properties of the solid electrolyte itself from the measured data. (2) Supply the gas to be measured to the working electrode side of the solid electrolyte, supply constant voltage or constant current controlled power to the solid electrolyte according to the triangular wave potential, change the supplied power, and Measure the current value for the applied potential or the voltage value for the supplied current, subtract the baseline data from the above measurement data,
A gas cyclic voltammetry measurement method characterized by determining a current-potential curve of a gas to be measured. (3) A detector equipped with a solid electrolyte and capable of supplying a gas to be measured to the working electrode side of this solid electrolyte, a function generator that generates a triangular wave potential, and a detector that is capable of supplying a gas to be measured to the working electrode side of this solid electrolyte, and a function generator that generates a triangular wave potential, and a detector that is capable of supplying a gas to be measured to the working electrode side of this solid electrolyte, and a function generator that generates a triangular wave potential. A potentiogalvanostat supplies constant voltage or constant current controlled power and measures the current value relative to the applied potential or the voltage value relative to the supplied current, and the above data is plotted with the potential on the X axis and the current on the Y axis. Cyclic voltammetry for gases, characterized in that it is equipped with a storage section that stores the captured wave data as wave data, and a calculation section that subtracts baseline data from the wave data to obtain a current-potential curve of the gas to be measured. measuring device. (4) Supply the gas to be measured to the working electrode side of the solid electrolyte, supply constant voltage or constant current controlled power to the solid electrolyte, and measure the current or voltage value that changes depending on the reaction of the gas to be measured. Obtain the polarization curve by measuring each potential or each current, obtain the IR resistance during the above measurement, and obtain the Tafel line based on the polarization curve of the gas to be measured obtained by subtracting the IR resistance from the above polarization curve. A method for measuring Tafel lines for gases. (5) A detector equipped with a solid electrolyte and capable of supplying a gas to be measured to the working electrode side of the solid electrolyte, a function generator that sets the potential, and a constant voltage or constant voltage based on the potential from the function generator. A potentiogalvanostat that supplies current-controlled power to the solid electrolyte, measures the current value or voltage value that changes depending on the reaction of the sample gas for each potential or each current, and determines the IR resistance during the measurement. A Tafel line measurement device for a gas, comprising: a calculation unit that subtracts the IR resistance from the measurement data to obtain a polarization curve of the gas to be measured, and creates a Tafel line based on this data. (6) Supply the gas to be measured to the working electrode side of the solid electrolyte, and supply constant voltage or constant current controlled power to the solid electrolyte according to the waveform of the AC potential, thereby reducing the distorted current or potential. A method for measuring the complex impedance of a gas, characterized in that strain is measured, each impedance component is calculated, and the impedance of the solid electrolyte itself is subtracted from the impedance component determined above to obtain the complex impedance of the gas to be measured. (7) A detector equipped with a solid electrolyte and capable of supplying a gas to be measured to the working electrode side of the solid electrolyte, and supplying electric power controlled at constant voltage or constant current to the solid electrolyte in accordance with the waveform of the AC potential. and a potentiogalvanostat that measures the distorted current or potential; a frequency characteristic analyzer that generates the alternating current potential and calculates each impedance component based on the measurement data from the potentiogalvanostat; From each impedance component obtained by calculation,
1. An apparatus for measuring the complex impedance of a gas, comprising: an arithmetic unit that calculates the complex impedance of the gas to be measured by subtracting the impedance of the solid electrolyte itself.