Flow-type cell

Abstract

A flow-type cell (1) according to the present disclosure comprises: a main body portion (15) to which a first liquid is supplied; a reaction portion (42) that is disposed so as to be capable of coming into contact with the first liquid and provides a reaction field for causing at least the first liquid to undergo a chemical reaction; and a spectroscopic window (55) that is disposed at a position facing the reaction field and is disposed such that the chemical reaction in the reaction field can be observed using light. The reaction portion is configured such that a reaction fluid is supplied to the reaction field or a generated fluid generated from the reaction field is discharged.

Description

Flow-type cell

[0001] This invention relates to a flow-type cell. This application claims priority under U.S. Patent Application No. 63 / 751,281, filed in the United States on 30 January 2025, the contents of which are incorporated herein by reference.

[0002] Conventionally, spectrometers are known for observing the chemical reactions of substances such as a first liquid (see, for example, Non-Patent Document 1). Spectrometers observe substances using light such as infrared light.

[0003] Ken-ichi Ataka, Takao Yotsuyanagi, Masatoshi Osawa, “Potential-Dependent Reorientation of Water Molecules at an Electrode / Electrolyte Interface Studied by Surface-Enhanced Infrared Absorption Spectroscopy”, J. Phys. Chem. 1996, 100, p.10664-10672

[0004] To facilitate observation of the first liquid, a flow-type cell containing the substance is used, which is detachable from the spectrometer. This flow-type cell continuously supplies fluid to the reaction field, allowing observation of the chemical reaction while simultaneously discharging the fluid from the reaction field. When the first liquid undergoes a chemical reaction in the reaction field, bubbles may be generated. In this case, the bubbles make it difficult to observe the chemical reaction of the first liquid.

[0005] This disclosure is made in view of the circumstances described above, and aims to provide a flow cell that can more reliably observe the chemical reaction of the first liquid even when bubbles are generated in the reaction field.

[0006] To solve the aforementioned problems, this disclosure proposes the following means. The flow cell of this disclosure comprises a main body to which a first liquid is supplied; a reaction section arranged to be in contact with the first liquid and providing a reaction field for chemically reacting at least the first liquid; and a spectroscopic window positioned opposite the reaction field and arranged so that the chemical reaction in the reaction field can be observed by light, wherein the reaction section is configured to supply a reaction fluid to the reaction field or to discharge a generated fluid generated from the reaction field.

[0007] According to this disclosure, even when bubbles are generated in the reaction field, the chemical reaction of the first liquid can be observed more reliably.

[0008] This is a front view showing the overall configuration of the flow cell of the first embodiment of this disclosure. This is a cross-sectional view of the flow cell from the front. This is an enlarged view of part A1 in Figure 2, showing the electrode catalyst, working electrode holder, and fixing holder of the flow cell. This is a cross-sectional view of the fixing holder and the like from the front. This is a cross-sectional view of the working electrode rod from the front. This is a cross-sectional view of the main parts of the working electrode rod and fixing holder from the front. This is a plan view of the main body. This is a left side view of the main body. This is a front view of the main body. This is a right side view of the main body. This is a bottom view of the main body. This is a plan view of the base. This is a bottom view of the base. This is a cross-sectional view of the base from the front. This is a photograph of the working electrode holder (Ti fiber compression sheet) attached to the fixing holder. This shows the working electrode and electrode catalyst (IrO) attached to the fixing holder. ２ This is a photograph of a Ti felt. It also shows a flow cell assembled and connected to piping and a potentiostat. 0.1 M HClO ４ IrO during aqueous solution flow ２ This figure shows the results of OCP measurement between the Ti felt and the Hg / HgO reference electrode. ４ IrO in aqueous solution ２ This figure shows the results of the CV of OER using Ti felt. 0.1 M HClO ４ IrO in aqueous solution ２It is a diagram showing the CA result of OER by an Ir / Ti felt. In the OER in a 0.1 M HClO4 aqueous solution, when the applied voltage is OCP and 1.0, 1.5 V vs. SHE, IrO ２ It is a diagram showing the absorbance spectrum of the Ir / Ti felt surface. In the OER in a 1 M potassium phosphate aqueous solution adjusted to pH 14, when the current density is 1 A / cm ２ It is a diagram showing the absorbance spectrum of the Ni foam surface when the applied voltage is 1.9 V vs. SHE. It is a cross-sectional view of the main part of the flow cell of the second embodiment of the present disclosure, viewed from the front and disassembled. It is a cross-sectional view of the main part of the flow cell of the third embodiment of the present disclosure, viewed from the front.

[0009] (First Embodiment) Hereinafter, the first embodiment of the flow cell according to the present disclosure will be described with reference to FIGS. 1 to 22.

[0010] [I. Design of Flow Cell] As shown in FIGS. 1 and 2, the flow cell (hereinafter also simply referred to as a cell) 1 of the present embodiment is not designed specifically for a particular spectrometer, and can be used for various spectroscopic devices (not shown) by changing the connection part (pedestal part 10 described later) to an attachment (not shown) for total reflection absorption infrared spectroscopic measurement. In the design of the flow cell 1, importance is attached to safety, excellent usability, and stable operation. In particular, the possibility of liquid leakage of the reaction solution, which causes damage or contamination of the infrared spectroscopic device and deterioration of the quality of the measurement results, is thoroughly eliminated.

[0011] The overall view of the flow cell 1 in FIG. 1 and the cross-sectional view of the flow cell 1 shown in FIG. 2 show the overall configuration and internal flow path of the cell 1. As shown in FIGS. 1 to 3, this flow cell 1 is composed of a pedestal part 10, a main body part 15, a working electrode 26, a working electrode holding part 27, a fixed holder 30, a working electrode rod 35, a counter electrode part 45, a diaphragm part 50, and a crystal (spectroscopic window) 55 for total reflection absorption infrared spectroscopy. Note that the working electrode 26 and the working electrode holding part 27 together (provided) constitute the working electrode part 25. The working electrode 26, the working electrode holding part 27, the fixed holder 30, and the working electrode rod 35 together constitute the reaction part 42.

[0012] Each part, each electrode, and the connection parts such as pipes are tightened with screws or the like and perfectly sealed using an O-ring, packing, or ferrule. The electrode catalyst (catalyst) 28 held on the working electrode 26 is arranged so as to be directly pressed onto the crystal 55 for total reflection absorption infrared spectroscopy (see Fig. 3). This cell 1 can be used as an electrochemical reaction cell of a two- or three-electrode system or a one- or two-chamber system depending on the presence or absence of a diaphragm and a reference electrode.

[0013] Hereinafter, the side where the working electrode rod 35 protrudes with respect to the main body 15 may be referred to as "upward", the member on the side where the working electrode rod 35 protrudes may be referred to as "upper part", and the end may be referred to as "upper end". Also, the side where the pedestal 10 is located with respect to the main body 15 may be referred to as "downward", the member on the side where the pedestal 10 is located may be referred to as "lower part", and the end may be referred to as "lower end". Further, the side where the large-diameter 16-mm access port 15c (see Fig. 9) described later of the main body 15 is provided may be referred to as "front", and the member on the side where the large-diameter 16-mm access port 15c is provided may be referred to as "front part".

[0014] 〔I.A. Working Electrode and Working Electrode Holding Part, Fixed Holder〕 The working electrode 26 holds the electrode catalyst 28, and the working electrode holding part 27 and the fixed holder 30 serve to fix the working electrode 26 (see Fig. 4). In this example, the working electrode 26 is bent so as to be convex downward. The working electrode 26 (electrode catalyst 28) has an electrode catalyst surface (reaction field) 28a and is made of a fluid-permeable member such as a metal mesh or a metal porous body. This fluid permeability enables a smooth supply of fresh reaction solution to the electrode catalyst surface 28a arranged at a position facing the crystal 55 for total reflection absorption infrared spectroscopy and the discharge of the solution after the reaction (see Fig. 3). Also, since the ion flow between the working electrode 26 and the counter electrode (not shown) of the counter electrode part 45 is ensured, a stable electrochemical reaction can be performed.

[0015] In other words, the electrode catalyst 28 is supported on the electrode catalyst surface 28a. The electrode catalyst surface 28a is positioned opposite the crystal 55. The electrode catalyst surface 28a is positioned so that the chemical reaction on the electrode catalyst surface 28a can be observed by light such as infrared light from a spectrometer. The electrode catalyst surface 28a is formed on the working electrode 26. The reaction section 42 provides the electrode catalyst surface 28a. The working electrode 26 is positioned opposite the crystal 55.

[0016] The working electrode holder 27 is responsible for supplying and discharging the reaction gas (reaction fluid; second reaction fluid) to the electrode catalyst 28, and for maintaining uniform contact with the crystal 55 for total reflectance absorption infrared spectroscopy. In other words, the reaction section 42 is configured so that the reaction gas is supplied to the electrode catalyst surface 28a. The configuration for supplying the reaction gas can be formed in the internal space 36c of the working electrode rod 35, which will be described later. The reaction fluid may be a reaction liquid, which is a liquid supplied to the electrode catalyst surface 28a.

[0017] The working electrode holder 27 is made of a fluid-permeable substrate (fluid-permeable substrate). The fluid-permeable substrate (working electrode holder 27) is made of metal mesh, metal porosity, porous alumina, etc. The working electrode 26 is placed on the fluid-permeable substrate (working electrode holder 27). The working electrode holder 27 has a shape in which its center protrudes downward and is attached to the fixing holder 30 so as to protrude downward from the fixing holder 30. The electrode catalyst 28 is bent along the lower part of the working electrode holder 27 and is fixed by having its outer edge sandwiched between the fixing holder 30 and the working electrode holder 27.

[0018] As described above, the working electrode section 25, which has a working electrode 26 and a working electrode holding section 27, is fluid permeable. The working electrode section 25 is an electrically conductive mesh or an electrically conductive porous body. Through the fluid permeable substrate (working electrode holding section 27), it is possible to supply reaction gas to the working electrode 26 and discharge the generated gas (generated fluid) (see Figure 4). That is, the reaction section 42 is configured so that the generated gas generated from the electrode catalyst surface 28a is discharged. The configuration for discharging the generated gas can be formed in the internal space 36d of the working electrode rod 35, which will be described later. The generated fluid may be a generated liquid, which is a liquid generated from the electrode catalyst surface 28a.

[0019] As shown in Figure 4, the fixing holder 30 includes a first fixing holder (first fixing part) 31 and a second fixing holder (second fixing part) 32. The first fixing holder 31 and the second fixing holder 32 are each formed in a cylindrical shape. A female thread 31a is formed on the inner circumferential surface of the upper part of the first fixing holder 31. A male thread 31b is formed on the outer circumferential surface of the lower part of the first fixing holder 31. A locking part 32a protruding radially inward is provided at the lower end of the second fixing holder 32. A female thread 32b is formed on the inner circumferential surface of the second fixing holder 32 above the locking part 32a. The female thread 32b fits into the male thread 31b of the first fixing holder 31. In other words, the second fixing holder 32 is detachable from the first fixing holder 31.

[0020] In this example, the first fixing holder 31 and the second fixing holder 32 are made of a material that does not have electrical conductivity. However, the first fixing holder 31 and the second fixing holder 32 may be made of a metal that does have electrical conductivity. In this case, since the stainless steel plate electrode 37 is connected to the working electrode 26 via the first fixing holder 31 and the second fixing holder 32, electrical conductivity in the working electrode holding portion 27 becomes unnecessary.

[0021] The working electrode 26 is firmly fixed together with the fluid-permeable substrate (working electrode holding portion 27) between the first fixing holder 31 (fixing holder 30 (upper)) and the second fixing holder 32 (fixing holder 30 (lower)), thereby maintaining flatness on the fluid-permeable substrate (working electrode holding portion 27) and allowing the entire surface of the working electrode 26 to be pressed against the crystal 55. That is, the lower end of the first fixing holder 31 and the locking portion 32a of the second fixing holder 32 hold the working electrode portion 25.

[0022] Uniform pressure of the entire surface of the working electrode 26 against the crystal 55 is an important factor in obtaining a good infrared signal from the electrode catalyst surface 28a in total internal reflection absorption infrared spectroscopy. Depending on the measurement conditions, it may be necessary to separate the electrode catalyst surface 28a from the crystal 55. For this reason, it is preferable to be able to adjust the distance between the electrode catalyst surface 28a and the crystal 55 within a range of 0 mm to 1 mm by, for example, adjusting the screws provided on the crystal holding member and the working electrode rod 35.

[0023] The working electrode 26 and the working electrode holder 27 were designed to be the largest possible size to match the size of the crystal 55 used to maximize the infrared signal intensity and simplify the installation of the working electrode. In this flow cell 1, for example, for a crystal 55 with a diameter of 20 mm, the diameters of the working electrode 26 and the fixing holder 30 were 6.5 mm and 12 mm, respectively. If the working electrode 26 is very small, this can be accommodated by using a fixing holder 30 with a smaller hole.

[0024] As shown in Figures 5 and 6, the working electrode 26, working electrode holder 27, and fixing holder 30 are attached to the lower end of the working electrode rod 35 (described later) using a screw mechanism (see Figure 6 in particular). By making these components function as a sample holder independent of the working electrode 26 (working electrode rod 35) of the main body, the handling of the electrode catalyst 28 during installation is made easier, and the time and simplification of installation to the main body (working electrode rod 35) are reduced. Furthermore, by providing multiple sets of these components, the sample exchange time during measurement is also reduced.

[0025] [I. B. Working electrode rod and gas supply / discharge mechanism] The working electrode rod 35 is responsible for electrical connection to the working electrode 26, supplying and discharging gas, and stably pressing the working electrode 26 against the crystal 55. The working electrode rod 35 is composed of a cylindrical shaft (tubular part) 36 and a stainless steel plate electrode (divided member) 37 (see Figures 5 and 6). The working electrode rod 35 may also have components other than the cylindrical shaft 36 and the stainless steel plate electrode 37. The cylindrical shaft 36 is formed in a cylindrical shape. A male screw 36e is formed on the outer circumferential surface of the lower part of the cylindrical shaft 36.

[0026] The male thread 36e of the cylindrical shaft 36 is fitted into the female thread 31a of the first fixing holder 31. In other words, the first fixing holder 31 is detachable from the cylindrical shaft 36.

[0027] For example, the stainless steel plate electrode 37 is made of a conductive material such as stainless steel and is formed in a flat plate shape. The stainless steel plate electrode 37 is arranged to extend in the direction of the long axis so as to divide the inside of the cylindrical shaft 36 into two in a direction perpendicular to the long axis direction (up and down direction). The lower tip of the stainless steel plate electrode 37 is electrically connected to the electrode catalyst 28 by contacting the working electrode holding part 27.

[0028] Furthermore, as shown in Figure 5, the stainless steel rod 38 at the top of the stainless steel plate electrode 37 is exposed to the outside (above) of the cylindrical shaft 36. The top of the cylindrical shaft 36 is fitted with a reaction gas inlet 36a and a reaction gas outlet 36b, which lead to the internal spaces 36c and 36d of the cylindrical shaft 36, which are divided into two parts by the stainless steel plate electrode.

[0029] The reaction gas is supplied from the reaction gas inlet 36a through one internal space (fluid supply passage) 36c of the cylindrical shaft 36 to the fluid-permeable substrate of the working electrode holding portion 27 at the tip of the cylindrical shaft 36. Then, the reaction gas and the generated gas discharged from the working electrode 26 are discharged from the reaction gas outlet 36b through the other internal space (fluid discharge passage) 36d of the cylindrical shaft 36. Internal space 36c supplies the reaction gas to the electrode catalyst surface 28a. Internal space 36d discharges the generated gas from the electrode catalyst surface 28a. The reaction section 42 comprises internal spaces 36c and 36d.

[0030] In other words, the stainless steel plate electrode 37 is positioned inside the cylindrical shaft 36, and by dividing the inside of the cylindrical shaft 36, an internal space 36c and an internal space 36d are formed inside the cylindrical shaft 36. This two-part cylindrical structure realizes a one-way gas flow path for supply and exhaust via the electrode catalyst 28.

[0031] Furthermore, in order to stably press the working electrode rod 35 against the crystal 55, a mounting base 39 for a vertical pressure load device and a pressure gauge for pressure monitoring is provided at the top of the working electrode rod 35. The pressure load device and pressure gauge allow the pressing pressure to be controlled to a constant level.

[0032] [I.C. Main body and liquid flow path] As shown in Figures 1 to 3, the main body 15 firmly fixes the other parts and forms a reaction liquid flow path to the electrode catalyst 28 (see Figures 2 and 3 in particular). The reaction liquid (first liquid; first reaction liquid) is introduced from the liquid inlet 16 at the top of the main body 15 and enters the pre-chamber (first chamber) 15a, which is a small space upstream of the working electrode rod 35. In other words, the reaction liquid is supplied to the main body 15.

[0033] The reaction liquid is then supplied to the electrode catalyst surface 28a by passing through the gap between the crystal 55 and the working electrode 26 and through the interior of the working electrode 26 (see Figure 3 in particular). The electrode catalyst surface 28a is positioned to be in contact with the reaction liquid and to at least chemically react with the reaction liquid. The liquid after the reaction is discharged from the liquid outlet 17 at the top of the main body 15 through the rear chamber (second chamber) 15b, which is a large space downstream of the working electrode rod 35. That is, the main body 15 comprises a front chamber 15a and a rear chamber 15b. The first chamber 15a contains the reaction liquid. The second chamber 15b contains the liquid after the reaction. This liquid after the reaction may be a generated fluid generated from the electrode catalyst surface 28a.

[0034] In other words, the electrode catalyst surface 28a of the working electrode 26 and the crystal 55 are positioned between the front chamber 15a and the rear chamber 15b. The reaction liquid and the reaction gas supplied through the gas channel undergo an electrochemical reaction at the electrode catalyst surface 28a, generating a gas that is discharged from a gas channel (fluid discharge channel, internal space 36d) separate from the gas channel (fluid supply channel, internal space 36c) through which the reaction gas flowed. The liquid discharge port 17 is positioned above the main body 15 so that if gas generated from the working electrode 26 flows into the rear chamber 15b, it will be quickly discharged to prevent the gas from remaining in the flow-type cell 1 and hindering the electrochemical reaction.

[0035] Figures 7 to 11 show the detailed locations of connection ports, connecting pipes, and access ports on each side of the main body 15. The front chamber (first chamber) 15a and the rear chamber (second chamber) 15b are each provided with internal access ports, allowing for the insertion of sensors such as thermometers and pH meters, as well as thin tubes for separating the liquids before and after the reaction. This enables sequential measurement of physical properties of the liquids before and after the reaction. In particular, the front chamber 15a is equipped with a 6 mm diameter access port 15g, enabling sequential measurement of the liquid temperature immediately before the catalytic reaction. The rear chamber 15b is equipped with a large diameter 16 mm access port 15c, allowing for the insertion of spectroscopic probes such as Raman spectroscopy probes, enabling in-situ spectroscopic measurement of the liquid after the catalytic reaction.

[0036] Figures 7 to 11 show the insertion port 15d for the working electrode rod 35 and the insertion port 18 for the preparative tubing. For example, this flow cell 1 has three liquid inlet ports 16. This is because it is intended for reaction liquid modulation excitation spectroscopy, in which spectroscopic measurements are performed while switching between reaction liquids.

[0037] Modulated excitation spectroscopy involves performing reaction and spectroscopic measurements while periodically modulating the intensity of factors involved in the reaction. By analyzing the changes in the spectral signal intensity and the phase of factor intensity modulation, this method allows for highly sensitive and highly temporally resolving measurement of infrared signal changes associated with reaction changes. One example of a combination of liquids introduced from the three ports of the liquid inlet 16 is a high-concentration reaction liquid, a low-concentration reaction liquid, and a non-reactive liquid. Furthermore, in order to minimize the time difference between the time the introduced liquid is switched and the time the switched liquid actually reaches the electrode catalyst 28, the volume of the pre-chamber 15a, which is a factor in the time difference, was minimized.

[0038] As shown in Figure 2, the main body 15 is provided with a temperature-controlled liquid channel (temperature control section) 15e inside, which surrounds the working electrode rod 35 and the pre-chamber 15a to adjust the temperature of the reaction liquid. A temperature-controlled medium (not shown) can flow through the liquid channel 15e. In other words, the main body 15 is equipped with a liquid channel 15e to adjust the temperature of the reaction liquid. In this way, the temperature of the flow-type cell 1 near the electrode catalyst 28 can be maintained.

[0039] [I.D. Counter Electrode Section and Diaphragm Section, Electrode Arrangement] The electrode arrangement was considered to ensure a stable electrochemical reaction. As described above, electrical conductivity is ensured between the electrode catalyst 28 and the stainless steel rod 38 on the opposite side through the stainless steel plate electrode 37 inside the working electrode rod 35. The working electrode of the potentiostat (external power supply section, not shown) is connected to this stainless steel rod 38. That is, the stainless steel plate electrode 37 electrically connects the working electrode of the potentiostat to the working electrode 26. The reference electrode is inserted in the front-to-back direction (lateral direction) through an insertion opening 15f provided on the front near the bottom of the main body. The insertion opening 15f is positioned so that the distance between the tip of the reference electrode and the electrode catalyst 28 is as short as possible. The insertion opening 15f is designed to accommodate a reference electrode with a diameter of 6 mm.

[0040] As shown in Figure 2, the counter electrode (not shown) is provided in the counter electrode section 45, which has an independent large space (third chamber) 45a on the rear chamber 15b side of the main body section 15. That is, the counter electrode is placed in the large space 45a and the second liquid is supplied to it. This is to make the counter electrode as large and surface area as possible, thereby preventing the performance of the counter electrode from becoming the rate-limiting factor of the entire reaction and achieving ideal electrochemical measurement.

[0041] A diaphragm section 50, equipped with a diaphragm 51 such as an ion exchange membrane (with the diaphragm 51 attached), is installed between the counter electrode section 45 and the main body section 15. The diaphragm 51 is positioned between the working electrode 26 and the counter electrode. The diaphragm section 50 is connected to the counter electrode section 45 and the main body section 15. The diaphragm 51 is made as large in area (diameter 23 mm) as possible for the size of this flow-type cell 1 so that the diaphragm 51 does not become the rate-limiting factor in ion conduction. This diaphragm 51 separates the flow path of the main body section 15 from the flow path of the counter electrode section 45, thereby forming a two-chamber electrochemical cell. Note that the diaphragm 51 may not be essential depending on the reactants and products involved in the reaction in the reaction field.

[0042] [I. E. Base and Total Internal Reflection Absorption Infrared Spectroscopy Crystal] The base 10 plays a role in fixing the main body 15 and the total internal reflection absorption infrared spectroscopy crystal 55 in place when the flow cell 1 is installed on the infrared spectrometer (spectrometer). Typically, each infrared spectrometer is equipped with an attachment for total internal reflection infrared spectroscopy that matches the specifications of the instrument. The base 10 needs to be designed taking into account the characteristics of this attachment, such as the incident direction of infrared light and the reflection direction to the detector, the shape of the crystal 55, the appropriate placement of the crystal 55, and the shape of the mounting opening. In this case, the base 10 was designed and manufactured to match the total internal reflection infrared spectroscopy attachment (VeeMAXIII) manufactured by PIKE (see Figures 12 to 14).

[0043] The shape of the Crystal 55 is selected to match the attachment, as mentioned above. The material of the Crystal 55 must be selected considering its ability to sufficiently transmit infrared light in the wavenumber region for which spectroscopic measurement is desired, and also taking the measurement conditions into account. Candidate materials for reaction measurements in aqueous solutions include silicon (Si), germanium (Ge), diamond, and calcium fluoride (CaF). ２ ), barium fluoride (BaF ２ Examples include zinc selenide (ZnSe) and KRS-5 (a mixed crystal of TiBr and TiI). In this case, a trapezoidal, single-reflection Ge crystal with a sample contact surface of 20 mm was selected. Then, with the crystal 55 supported from below by the crystal holder 11, the crystal holder 11 is fixed to the base portion 10 with screws, thereby fixing the crystal 55 in the appropriate position.

[0044] [II. Stable Flow of Liquids and Gases] One of the main functions of this flow-type cell 1 is to supply a stable flow of liquids and gases to the electrode catalyst surface 28a. To confirm the supply of a stable flow of liquids and gases, each pipe was connected to the flow-type cell 1, pump, and liquid tank, and after assembly, liquids and gases were flowed through the cell to perform an airtightness test of the entire cell and to confirm the macroscopic flow.

[0045] A gas mass flow meter was connected to the reaction gas inlet 36a, and liquid supply pumps were connected to the liquid inlets of the main body 15 and the counter electrode 45, respectively. In other words, by supplying gas and liquid under pressure into the flow cell 1, the inside of the flow cell 1 was made to have positive pressure. Furthermore, as the electrode catalyst 28, iridium oxide (IrO2) supported on titanium (Ti) felt, which exhibits high activity in the oxygen evolution reaction (OER) by water electrolysis, was used. ２ ) (IrO ２ Ti felt was used. In this setup, since the Ti felt, which is the carrier, is fluid permeable, the Ti felt also serves as the working electrode 26. A Ti fiber compressed sheet was used for the working electrode holding part 27.

[0046] These Iro ２ Ti felt and Ti fiber compression sheets were cut out and fixed inside the fixing holder 30 (see Figures 15 and 16). As a result, no liquid leakage was observed from the connection part of the flow cell 1, and airtightness was maintained. In this test, when the gas (Ar) introduction flow rate was set to 15 mL / min., there was no intrusion of liquid into the gas flow path, and a stable flow of liquid and gas on a macroscopic level was achieved. In addition, it was confirmed that this stable flow was maintained for more than 2 hours. The pressure of the liquid inside the flow cell 1 is thought to change depending on the delivery speed and pressure conditions of the liquid delivery pump. Therefore, it is necessary to adjust the conditions such as the flow velocity and pressure of the introduced gas for each experimental condition.

[0047] [III. Performance as an Electrochemical Experiment Cell] Performance tests were conducted on this flow-type cell 1 as an electrochemical experiment cell. The test method involved confirming the stability of the measurement environment and electrochemical reaction when liquids and gases were circulated using an electrochemical measurement setup. Similar to the flow test described above, IrO was used as the electrode catalyst and working electrode (WE). ２ Ti felt and a Ti fiber compression sheet were used as the working electrode holder. The fixing holder was attached to the working electrode rod (working electrode part), and IrO was tested using a circuit tester. ２Electrical continuity between the Ti felt and the stainless steel rod was confirmed.

[0048] The conditions for the following electrochemical experiment are: IrO ２ Literature on OER using base catalysts was consulted (Reference [1]). The reference electrode (RE), counter electrode (CE), and ion exchange membrane were each supplied with carmelo (Hg / Hg ２ Cl ２ A saturated KCl electrode, a platinum (Pt) plate (20 x 20 mm), and a proton exchange membrane (Nafion 115) were used. Figure 17 is a photograph of the assembled flow cell connected to the piping and potentiostat. The reaction liquid was 0.1 MHClO on both the working electrode and counter electrode sides. ４ An aqueous solution was used. During the experiment, the liquid was continuously circulated within a flow cell, and the discharged liquid was collected in a liquid tank and reused as the reaction liquid. In addition, Ar was continuously flowed through the reaction gas inlet at a rate of 15 mL / min.

[0049] Electrochemical measurements were performed at room temperature using open-circuit potential (OCP), cyclic voltammetry (CV), and chronoamperometry (CA) under OER (Open Circuit Emission). CV measurements were performed over 6 cycles at a sweep rate of 10 mV / s within the range of 0.2–1.5 V vs. SHE (Standard Hydrogen Electrode). CA measurements were performed over 350 s at 1.5 V vs. SHE, where OER occurs.

[0050] [III. A. Stability of the Electrochemical Measurement Environment] First, the stability of the measurement environment was confirmed by OCP measurement. Although slight fluctuations were observed in OCP, it remained stable around 0.36 V vs. SHE (see Figure 18). Figure 18 shows 0.1 MHClO ４ These are the results of OCP measurements during aqueous solution flow. The inset in Figure 18 is a magnified view of the 50-200 s region. WE, CE, RE, and the ion exchange membrane are each IrO ２Ti felt, Pt plate, Hg / Hg ２ Cl ２ The electrodes (saturated KCl) and Nafion 115 were used to form the OCP. The measurements were performed at room temperature. Therefore, it was determined that a sufficiently stable environment for electrochemical measurements was achieved. Furthermore, the minute fluctuations in the OCP showed periodicity (see inset in Figure 18). This periodic fluctuation of the OCP is thought to be due to periodic changes in the environment near the electrode surface, specifically the micro-flow. The liquid delivery pump used in this study had pulsation in the delivery velocity, and it is believed that this pulsation caused periodic changes in the flow, leading to the minute fluctuations in the OCP. It may be possible to achieve an even more stable measurement environment by using a liquid delivery pump without pulsation.

[0051] [III. B. Stability of Electrochemical Reaction under Gas Evolution Conditions] Next, the stability of the electrochemical reaction under gas (oxygen) evolution conditions was confirmed by CV and CA measurements. The CV measurement was completed without overload for 6 cycles (approximately 25 minutes), and the CV curves for each cycle were roughly in agreement (see Figure 19). Figure 19 shows 0.1 MHClO ４ IrO in aqueous solution ２ This is the result of CV of OER using Ti felt. CE, RE, and ion exchange membrane are IrO ２ Felt and Pt plate, Hg / Hg ２ Cl ２ The electrodes (saturated KCl) were formed using Nafion 115. The measurements were performed at room temperature. The results in Figure 19 indicate that the large bubbles generated on the electrode catalyst surface did not remain, and the reaction area between the catalyst and the solution did not change significantly. Furthermore, the onset potential estimated for each cycle was approximately 1.1 V vs. SHE, which was in close agreement with the onset potential value in reference [1].

[0052] Therefore, this flow cell and experimental conditions are IrO ２We believe that we have achieved OER using the catalyst. On the other hand, under OER conditions of 1.1V vs. SHE or higher, large fluctuations are observed in the CV curve. This is thought to be due to repeated adsorption and desorption of small bubbles generated on the catalyst surface. To suppress these fluctuations, it is necessary to increase the removal efficiency of the generated gas from the electrode catalyst surface. We believe that this improvement in removal efficiency can be achieved by adjusting the material of the working electrode and the working electrode holder, as well as the liquid flow rate.

[0053] The CA measurement was also completed without overloading under OER conditions (1.5V vs. SHE) for the set duration of 350 seconds. The current value during the CA measurement remained stable at approximately 10mA, although some fluctuations were observed (see Figure 20). Figure 20 shows 0.1 MHHClO. ４ IrO in aqueous solution ２ This is the result of CA of OER using Ti felt. CE, RE, and ion exchange membrane are IrO ２ Felt and Pt plate, Hg / Hg ２ Cl ２ The electrodes (saturated KCl) were formed using Nafion 115. Measurements were taken at room temperature. 10 mA corresponds to approximately 30 mA / cm², assuming a WE size of 6.5 mm in diameter. ２ This indicates that the reaction area between the catalyst and the solution was maintained even under continuous oxygen (gas) generation. From this, it can be said that this flow-type cell and conditions demonstrated the ability to maintain a stable OER by rapidly removing the gas generated under OER from the catalyst surface. Furthermore, as mentioned in the CV measurement results, the fluctuation in the current value during OER is thought to be due to the intermittent adsorption and desorption of small bubbles to and from the catalyst surface. From the above CV and CA measurement results, the stability of this flow-type cell as an electrochemical experimental cell and the stable and continuous OER conditions were confirmed.

[0054] [IV. In-situ infrared spectroscopy measurement of electrode catalysts] Performance tests were conducted on the electrode catalyst of this flow-type cell as an in-situ total reflection absorption infrared spectroscopy cell. The test method was as follows: ２ Using the conditions of the OER experiment by Ti Felt, IrO in the OER ２Total internal reflection absorption infrared spectroscopy measurements were performed on the surface of Ti felt. The infrared spectrometer and attachment used were a Bruker INVENIO R and a PIKE VeeMAX III, both equipped with liquid nitrogen-cooled mercury-cadmium-tellurium (MCT) detectors, respectively. The infrared light path inside the spectrometer and attachment was continuously purged with dry air. Considering the wavenumber range of the acquired infrared spectrum and the pH of the solution, a Ge crystal was used for the total internal reflection absorption infrared spectroscopy crystal. The resolution, number of integrations, and aperture diameter were all set to 1 cm. －１ The values ​​were 512 times and 4 mm. Background was measured using infrared signals in a closed circuit (CC) with solution and gas flowing through it.

[0055] Figure 21 shows the absorbance spectra when the applied voltage is OCP and 1.0 and 1.5 V vs. SHE. The current densities for 1.0 and 1.5 V vs. SHE are approximately 0.3 and 30 mA / cm², respectively. ２ The OER spectrum did not show any changes in peaks related to water electrolysis. On the other hand, the spectra at 1.0 V vs. SHE near the OER onset potential and at 1.5 V vs. SHE where the reaction was occurring showed changes at 1635, 1351, and 1102 cm⁻¹. －１ A clear positive peak was observed. According to previous research (reference [2]), 1102 cm －１ The peak was adsorbed to Ir. ＊ This is thought to originate from the vibration of O-OH. Here, ＊ " represents the working electrode, and ＊ The "O-OH" designation indicates that the "O-OH" functional group is bonded to the working electrode.

[0056] 1635cm －１ The peak is H ２ Adsorbed onto O or Ir ＊ This can be attributed to the δOH oscillation of O-OH. 1351 cm －１ The peak could not be classified this time. It was adsorbed to Ir. ＊ O-OH is IrO ２Since it is thought to be an intermediate of OER due to the catalyst, the IrO in OER measured in this experiment ２ We can say that we succeeded in observing the intermediate on the catalyst surface in situ. －１ The peak intensity is stronger at 1.5V vs. SHE than at 1.0V vs. SHE, and with increasing current density, i.e., increased oxygen production, the peak intensity on Ir increases. ＊ It appears that the amount of OOH (out-of-home) material produced also increased.

[0057] Furthermore, under OER conditions, the wavenumber range for the vOH or δOH oscillations of water molecules is 3400 or 1600 cm⁻¹. －１ No negative peaks were observed in the vicinity. This suggests that the number of water molecules near the crystal surface, which is the observation surface, did not decrease. In other words, this flow-type cell effectively suppressed the accumulation of bubbles on the electrodiluted catalyst surface and the observation surface, which are factors that cause noise and baseline changes. From the results of the spectroscopic measurements above, it was shown that this flow-type cell enables in-situ infrared spectroscopic observation of the electrode catalyst surface.

[0058] [V. In-situ infrared spectroscopy measurement in OER with high current density] The performance of this flow-type cell as in-situ total internal reflection absorption infrared spectroscopy was tested under conditions where a large number of bubbles were generated on the electrode surface. The test method involved measuring a high current density (1 A / cm²) using Ni foam in a 1 M potassium phosphate aqueous solution adjusted to pH 14. ２ An OER experiment was conducted, and total internal reflection absorption infrared spectroscopy measurements were performed on the Ni foam surface in the OER. The infrared spectrometer, attachments, and crystals used were the same as those in the previous chapter. The resolution, number of integrations, and aperture diameter were 8 cm each. －１ The measurement was 32 times at 8 mm. Background was measured using infrared signals at open-circuit potential (OCP) with solution and gas flowing through the circuit.

[0059] Figure 22 shows a current density of 1 A / cm². ２The absorbance spectrum is shown when the applied voltage is 1.9 V vs. SHE. A clear spectrum was obtained despite the conditions of a large number of bubbles forming on the Ni foam surface under high current density. The 1.9 V vs. SHE spectrum includes values ​​of 1635, 1160, 1083, and 1041 cm⁻¹. －１ A positive peak was observed at 1160 cm. According to previous research (reference [3]), －１ The peak is due to NiOOH formed on the Ni surface. ＊ This is thought to originate from O-OH vibrations. 1635 cm －１ The peak is H ２ This can be attributed to the δOH oscillation of O at 1083 and 1041 cm⁻¹. －１ The peak is due to the electrolyte PO ４ ３－ It is thought to originate from the Ni surface. ＊ Since OOH is considered to be an intermediate in OER produced by a Ni-based catalyst, this measurement can be said to have successfully observed the intermediate on the Ni catalyst surface in OER in situ. Therefore, this demonstrates that this flow-type cell has the capability to acquire infrared spectra even under conditions where a large number of bubbles are generated at high current densities.

[0060] [References] [1] W. Sun et al., “Cerium Surface-Engineered Iridium Oxides for Enhanced Oxygen Evolution Reaction Activity and Stability”, ACS Appl. Energy Mater., 2020, 3, p.4432-4440. [2] H. Su et al., “In-situ spectroscopic observation of dynamic-coupling oxygen on atomically dispersed iridium [3] Y. Hu et al., “Understanding the sulphur-oxygen exchange process of metal sulphides prior to oxygen evolution reaction”, Nat. Commun., 2023, 14, 1949.

[0061] As described above, according to the flow cell 1 of this disclosure, for example, the flow cell 1 is attached to a spectrometer, and light irradiated from the spectrometer is passed through the crystal 55 and reflected off the electrode catalyst surface 28a. The reflected light is then measured by the spectrometer to observe the chemical reaction on the electrode catalyst surface 28a that causes the reaction liquid to chemically react. In this case, the reaction section 42 is configured so that a reaction gas is supplied to the electrode catalyst surface 28a, or generated gas generated from the electrode catalyst surface 28a is discharged. Therefore, compared to a configuration in which, for example, no reaction gas is supplied to the electrode catalyst surface 28a and generated gas is not discharged from the electrode catalyst surface 28a, it becomes easier to discharge bubbles generated on the electrode catalyst surface 28a, and the chemical reaction of the reaction liquid can be observed more reliably.

[0062] The reaction section 42 has a working electrode section 25, and the electrode catalyst surface 28a is formed on the working electrode 26. This allows for more reliable observation of the chemical reaction on the electrode catalyst surface 28a on which the working electrode 26 is formed, through the crystal 55. The working electrode section 25 is fluid permeable. Therefore, it is possible to easily flow at least one of the reaction liquid, reaction gas, and generated gas through the working electrode section 25 of the reaction section 42.

[0063] The working electrode portion 25 is an electrically conductive mesh or an electrically conductive porous body. Therefore, the working electrode portion 25 can be reliably permeable to fluids. The reaction portion 42 includes an internal space 36c and an internal space 36d. This allows the reaction gas to be supplied to the electrode catalyst surface 28a through the internal space 36c, and the gas generated on the electrode catalyst surface 28a to be discharged through the internal space 36d.

[0064] The reaction section 42 comprises a cylindrical shaft 36 and a stainless steel plate electrode 37. Therefore, the cylindrical shaft 36 and the stainless steel plate electrode 37 can easily form internal spaces 36c and 36d. The reaction section 42 has a working electrode section 25, and the stainless steel plate electrode 37 is made of a conductive material and electrically connects the power supply section and the working electrode 26. Therefore, power supplied from the power supply section can be supplied to the working electrode 26 via the stainless steel plate electrode 37.

[0065] The reaction fluid is a reaction gas. Therefore, the reaction fluid can be a gaseous reaction gas. The generated fluid is an generated gas. Thus, the generated fluid can be an generated gas.

[0066] The main body 15 comprises a front chamber 15a and a rear chamber 15b. Therefore, the front chamber 15a can contain the reaction liquid, and the rear chamber 15b can contain the liquid after the reaction. The electrode catalyst surface 28a and the crystal 55 are positioned between the front chamber 15a and the rear chamber 15b. This suppresses the mixing of the reaction liquid supplied from the front chamber 15a with the liquid after the reaction. In this suppressed state, for example, light irradiated from a spectrometer can be transmitted through the crystal 55 and reflected off the electrode catalyst surface 28a, allowing the reflected light to be measured by the spectrometer.

[0067] The flow cell 1 comprises a counter electrode section 45 and a diaphragm section 50. Therefore, the working electrode 26 and the counter electrode can be separated by the counter electrode section 45 and the diaphragm section 50, which is connected to the main body section 15 and to which the diaphragm 51 is attached. The distance between the electrode catalyst surface 28a and the crystal 55 can be adjusted to a range of 0 mm to 1 mm. In this case, a variety of spectroscopic measurement techniques are possible, enabling observation of electrode catalysts 28 in various forms.

[0068] The main body 15 is equipped with a liquid channel 15e. Therefore, the temperature of the reaction liquid can be adjusted by the liquid channel 15e. An electrode catalyst 28 is supported on the electrode catalyst surface 28a. As a result, the electrode catalyst 28 supported on the electrode catalyst surface 28a can promote the reaction of the reaction liquid.

[0069] The diaphragm 51 is an ion exchange membrane. Therefore, by performing ion exchange between the second liquid and the first liquid, for example, the accumulation of predetermined ions on the main body side can be suppressed, maintaining the reaction observation environment, and unintended reactions between the second liquid and the first liquid can be suppressed, for example, further reactions between the product of the working electrode 25 and the product of the counter electrode 45 can be suppressed, and only the product of the electrode catalyst 28 can be observed. The reaction section 42 comprises a cylindrical shaft 36, a first fixed holder 31, and a second fixed holder 32, and the first fixed holder 31 and the second fixed holder 32 hold the working electrode 25. For this reason, the first fixed holder 31 can be attached to and detached from the cylindrical shaft 36, and the second fixed holder 32 can be attached to and detached from the first fixed holder 31, and the working electrode 25 can be held by the first fixed holder 31 and the second fixed holder 32.

[0070] The reaction section 42 does not necessarily have to have at least one of the working electrode section 25, internal space 36c, internal space 36d, cylindrical shaft 36, stainless steel plate electrode 37, first fixed holder 31, and second fixed holder 32. In this case, the reaction field may be formed with a configuration other than the working electrode 26. The working electrode section does not necessarily have to be fluid permeable. The main body section 15 does not necessarily have to have at least one of the front chamber 15a, rear chamber 15b, and liquid flow path 15e.

[0071] At least one of the electrode catalyst surface 28a and the crystal 55 does not have to be placed between the front chamber 15a and the rear chamber 15b. The flow cell 1 does not have to have at least one of the counter electrode section 45 and the diaphragm section 50. The electrode catalyst 28 may be supported on a surface other than the electrode catalyst surface 28a.

[0072] (Second Embodiment) Next, a second embodiment of the present disclosure will be described with reference to Figure 23. The same reference numerals are used for parts identical to those in the previous embodiment, and their descriptions will be omitted. Only the differences will be described. As shown in Figure 23, the flow cell 2 of this embodiment has a flat working electrode 61 compared to the flow cell 1 of the first embodiment. In this example, a groove 32c for flowing reaction gas and generated gas is formed on the lower surface of the second fixed holder 32.

[0073] In the flow-type cell 2, power supplied from the power supply unit can be supplied to the working electrode 61 via the upper wiring 62 and the lower wiring 63.

[0074] (Third Embodiment) Next, a third embodiment of the present disclosure will be described with reference to Figure 24. The same reference numerals are used for parts that are the same as in the previous embodiments, and their descriptions will be omitted. Only the differences will be described. As shown in Figure 24, the flow cell 3 of this embodiment is equipped with a working electrode 71 in place of the working electrode 26 in each configuration of the flow cell 1 of the first embodiment.

[0075] The working electrode 71 includes a first working electrode 72, an insulating member 73, and a second working electrode 74. The first working electrode 72 and the second working electrode 74 are configured in the same way as the working electrode 26. Electrode catalysts may be supported on the first working electrode 72 and the second working electrode 74. The insulating member 73 has electrical insulating properties. The insulating member 73 may be configured as a diaphragm 51. The insulating member 73 is positioned between the first working electrode 72 and the second working electrode 74. The second working electrode 74 is connected to the first working electrode 72 via the insulating member 73.

[0076] The working electrode 71 is a membrane-electrode assembly (MEA).

[0077] In this embodiment, the reaction section 76 has a first wiring 77 and a second wiring 78 in place of the stainless steel plate electrode 37 in each configuration of the reaction section 42 of the first embodiment. The first wiring 77 has a first wiring first piece 77a, a first wiring second piece 77b, and a first wiring third piece 77c. The second wiring 78 has a second wiring first piece 78a and a second wiring second piece 78b. The first wiring first piece 77a, the first wiring second piece 77b, the first wiring third piece 77c, the second wiring first piece 78a, and the second wiring second piece 78b are made of a conductive material. Furthermore, the first wiring first piece 77a and the first wiring second piece 77b are electrically connected, and the first wiring second piece 77b and the first wiring third piece 77c are electrically connected. Furthermore, the first piece 78a of the second wiring and the second piece 78b of the second wiring are electrically connected.

[0078] The first wiring piece 77a and the second wiring piece 78a are provided on the cylindrical shaft 36. The second wiring piece 77b and the second wiring piece 78b are provided on the first fixed holder 31. The third wiring piece 77c is provided on the second fixed holder 32. In other words, the first wiring 77 is provided across the cylindrical shaft 36, the first fixed holder 31 and the second fixed holder 32, and the second wiring 78 is provided across the cylindrical shaft 36 and the first fixed holder 31. The first wiring 77 electrically connects the external power supply unit to the first working electrode 72. The second wiring 78 electrically connects the power supply unit to the second working electrode 74. In this example, a groove 32c for flowing reaction gas and generated gas is formed on the lower surface of the second fixed holder 32.

[0079] According to the flow-type cell 3 of this disclosure, the chemical reaction of the reaction liquid can be observed more reliably even when bubbles are generated in the reaction field. Furthermore, the first wiring 77 supplies power supplied from the power supply unit to the first working electrode 72, and the second wiring 78 supplies power supplied from the same power supply unit to the second working electrode 74.

[0080] <Additional Notes (Variations)> - In the above flow cell, only one fluid passage may be provided in the reaction section, or three or more fluid passages may be provided. Also, the first gas and the second gas may pass through the same fluid passage. - The above flow cell is not limited to infrared absorption spectroscopy, but can also be used for absorption spectroscopy of visible light, fluorescence spectroscopy, and Raman spectroscopy. - The above flow cell is not limited to the measurement of total reflected light, but can also be used for the measurement of diffuse reflected light. - The chemical reaction observed in the above flow cell is not limited to electrochemical reactions, but may also be a chemical reaction that does not involve power supplied from an external source.

[0081] - In the above flow cell, the substances constituting the reaction liquid may undergo a chemical reaction, or substances dissolved or dispersed in the reaction liquid may undergo a chemical reaction. - In the above flow cell, a chemical reaction in which the reaction liquid and reaction gas react to produce generated gas may be observed, a chemical reaction in which the reaction liquid reacts to produce generated gas (a chemical reaction in which the reaction gas is not involved) may be observed, or a chemical reaction in which the reaction liquid and reaction gas react (a chemical reaction in which no generated gas is produced) may be observed. - In the above flow cell, it is not limited to the case in which gas (reaction gas, generated gas) flows through both the fluid supply channel and the fluid discharge channel, and the fluid flowing through the fluid supply channel and the fluid discharge channel is not limited to gas, but may be a liquid, a gas-liquid mixture, or a multiphase fluid.

[0082] Flow-type cells allow for more reliable observation of the chemical reaction of the first liquid, even when bubbles are generated in the reaction field. Therefore, they have great potential for industrial application.

[0083] (Note) The above embodiment can be understood, for example, as follows.

[0084] <1> A flow cell according to one aspect of the present disclosure comprises a main body to which a first liquid is supplied; a reaction section arranged to be in contact with the first liquid and providing a reaction field for chemically reacting at least the first liquid; and a spectroscopic window positioned opposite the reaction field and arranged so that the chemical reaction in the reaction field can be observed by light, wherein the reaction section is configured to supply a reaction fluid to the reaction field or to discharge a generated fluid generated from the reaction field.

[0085] In this disclosure, for example, a flow cell is attached to a spectrometer, and light irradiated from the spectrometer is passed through a spectral window and reflected in the reaction field. The reflected light is then measured by the spectrometer to observe the chemical reaction in the reaction field in which the first liquid is chemically reacted. In this case, the reaction section is configured so that a reaction fluid is supplied to the reaction field, or a generated fluid generated from the reaction field is discharged. Therefore, compared to a configuration in which, for example, no reaction fluid is supplied to the reaction field and no generated fluid is discharged from the reaction field, it becomes easier to discharge bubbles generated in the reaction field, and the chemical reaction of the first liquid can be observed more reliably.

[0086] <2> In the flow cell according to <1>, the reaction section has a working electrode section equipped with a working electrode positioned opposite the spectroscopic window, and the reaction field may be formed on the working electrode. In this disclosure, the chemical reaction in the reaction field where the working electrode is formed can be observed more reliably through the spectroscopic window.

[0087] <3> In the flow-type cell according to <2> above, the working electrode portion may be fluid permeable. In this disclosure, it is possible to facilitate the flow of at least one of the first liquid, reaction fluid, and generated fluid to the working electrode portion of the reaction portion.

[0088] <4> In the flow cell according to <3> above, the working electrode portion may be a conductive mesh or a conductive porous body. In this disclosure, the working electrode portion can be reliably made permeable to fluids.

[0089] <5> In a flow cell according to any one of <1> to <4> above, the reaction section may further include a fluid supply passage for supplying the reaction fluid to the reaction field and a fluid discharge passage for discharging the generated fluid from the reaction field. In this disclosure, the reaction fluid can be supplied to the reaction field by the fluid supply passage, and the generated fluid from the reaction field can be discharged by the fluid discharge passage.

[0090] <6> In the flow cell according to <5> above, the reaction section may further include a cylindrical portion and a dividing member that divides the inside of the cylindrical portion while being positioned inside the cylindrical portion, thereby forming the fluid supply passage and the fluid discharge passage inside the cylindrical portion. In this disclosure, the fluid supply passage and the fluid discharge passage can be easily configured by the cylindrical portion and the dividing member.

[0091] <7> In the flow cell according to <6> above, the reaction section has a working electrode section which is positioned opposite the spectroscopic window, and the dividing member is made of a conductive material and may be electrically connected to an external power supply unit and the working electrode. In this disclosure, power supplied from the power supply unit can be supplied to the working electrode via the dividing member.

[0092] <8> In a flow cell according to any one of <1> to <7> above, the reaction fluid may be a reaction gas supplied to the reaction field. In this disclosure, the reaction fluid may be a reaction gas which is a gas.

[0093] <9> In a flow cell according to any one of <1> to <8> above, the generated fluid may be a generated gas generated from the reaction field. In this disclosure, the generated fluid may be a generated gas.

[0094] <10> In a flow cell according to any one of <1> to <9> above, the main body may include a first chamber for containing the first liquid and a second chamber for containing the liquid after the reaction. In this disclosure, the first chamber can contain the first liquid and the second chamber can contain the liquid after the reaction.

[0095] <11> In the flow cell according to <10>, the reaction field may be located between the first chamber and the second chamber, and the spectroscopic window may be located between the first chamber and the second chamber. In this disclosure, the mixing of the first liquid supplied from the first chamber with the liquid after the reaction is suppressed, and in this suppressed state, for example, light irradiated from a spectrometer can be transmitted through the spectroscopic window and reflected in the reaction field, and the reflected light can be measured by the spectrometer.

[0096] <12> The flow cell according to <11> may further include a counter electrode section having a third chamber in which a counter electrode is arranged and a second liquid is supplied, and a diaphragm section having a diaphragm attached to which a diaphragm is placed between the working electrode and the counter electrode, and which is connected to the counter electrode section and the main body section. In this disclosure, the working electrode and the counter electrode can be separated by a diaphragm section connected to the counter electrode section and the main body section, to which a diaphragm is attached.

[0097] <13> In a flow cell according to any one of <1> to <12> above, the distance between the reaction field and the spectroscopic window may be configured to be adjustable within a range of 0 mm or more and 1 mm or less. This disclosure enables a variety of spectroscopic measurement techniques and allows observation of various forms of electrode catalysts.

[0098] <14> In a flow cell according to any one of <1> to <13> above, the main body may further include a temperature control unit for adjusting the temperature of the first liquid. In this disclosure, the temperature of the first liquid can be adjusted by the temperature control unit.

[0099] <15> In a flow cell according to any one of <1> to <14> above, a catalyst may be supported on the reaction field. In this disclosure, the catalyst supported on the reaction field can accelerate the reaction of the first liquid.

[0100] <16> In the flow cell according to <12> above, the diaphragm may be an ion exchange membrane. In this disclosure, by performing ion exchange between the second liquid and the first liquid, for example, the accumulation of predetermined ions on the main body side can be suppressed and the reaction observation environment can be maintained, or unintended reactions can be suppressed between the second liquid and the first liquid, for example, further reactions between the product of the working electrode 25 and the product of the counter electrode 45 can be suppressed and only the product of the electrode catalyst 28 can be observed.

[0101] <17> In a flow cell according to any one of <2> to <16> above, the reaction section further comprises a cylindrical section, a first fixing section detachably attached to the cylindrical section, and a second fixing section detachably attached to the first fixing section, wherein the first fixing section and the second fixing section may hold the working electrode section. In this disclosure, the first fixing section is detachably attached to the cylindrical section, the second fixing section is detachably attached to the first fixing section, and the working electrode section can be held by the first fixing section and the second fixing section.

[0102] <18> In a flow cell according to any one of <1> to <17> above, the reaction section has a working electrode section having a working electrode positioned opposite the spectroscopic window, the working electrode having a first working electrode and a second working electrode connected to the first working electrode via an insulating member, the reaction section may have a first wiring made of a conductive material that electrically connects an external power supply unit to the first working electrode, and a second wiring made of a conductive material that electrically connects the power supply unit to the second working electrode. In this disclosure, the first wiring can supply power supplied from the power supply unit to the first working electrode, and the second wiring can supply power supplied from the power supply unit to the second working electrode.

[0103] <19> In the flow cell according to <18>, the reaction section further comprises a cylindrical portion, a first fixing portion detachable from the cylindrical portion, and a second fixing portion detachable from the first fixing portion, the first wiring is provided across the cylindrical portion, the first fixing portion, and the second wiring may be provided across the cylindrical portion and the first fixing portion.

[0104] 1, 2, 3 Flow Cell 15 Main body 15a Front chamber (first chamber) 15b Rear chamber (second chamber) 15e Liquid flow path (temperature control section) 25 Working electrode section 26, 61, 71 Working electrode 28 Electrode catalyst (catalyst) 28a Electrode catalyst surface (reaction field) 31 First fixing holder (first fixing section) 32 Second fixing holder (second fixing section) 36 Cylindrical shaft (tubular section) 36c Internal space (fluid supply passage) 36d Internal space (fluid discharge passage) 37 Stainless steel plate electrode (divided member) 42, 76 Reaction section 55 Crystal (spectroscopy window) 72 First working electrode 73 Insulating member 74 Second working electrode 77 First wiring 78 Second wiring

Claims

1. A flow cell comprising: a main body to which a first liquid is supplied; a reaction section arranged to be in contact with the first liquid and providing a reaction field for chemically reacting at least the first liquid; and a spectroscopic window positioned opposite the reaction field and arranged so that the chemical reaction in the reaction field can be observed by light, wherein the reaction section is configured to supply a reaction fluid to the reaction field or to discharge a generated fluid generated from the reaction field.

2. The flow cell according to claim 1, wherein the reaction section has a working electrode section that includes a working electrode positioned opposite the spectroscopic window, and the reaction field is formed in the working electrode.

3. The flow cell according to claim 2, wherein the working electrode portion is fluid permeable.

4. The flow cell according to claim 3, wherein the working electrode portion is a conductive mesh or a conductive porous body.

5. The flow cell according to claim 1, wherein the reaction section further comprises a fluid supply passage for supplying the reaction fluid to the reaction field, and a fluid discharge passage for discharging the generated fluid from the reaction field.

6. The flow cell according to claim 5, wherein the reaction section further comprises a cylindrical portion and a dividing member that divides the inside of the cylindrical portion while being positioned inside the cylindrical portion, thereby forming the fluid supply passage and the fluid discharge passage inside the cylindrical portion.

7. The flow cell according to claim 6, wherein the reaction section has a working electrode section that is positioned opposite the spectroscopic window, and the divided member is made of a conductive material and electrically connects an external power supply section to the working electrode.

8. The flow cell according to claim 1, wherein the reaction fluid is a reaction gas supplied to the reaction field.

9. The flow cell according to claim 1, wherein the generated fluid is a generated gas generated from the reaction field.

10. The flow cell according to claim 1, wherein the main body comprises a first chamber for containing the first liquid and a second chamber for containing the liquid after the reaction.

11. The flow cell according to claim 10, wherein the reaction field is located between the first chamber and the second chamber, and the spectroscopic window is located between the first chamber and the second chamber.

12. The flow cell according to claim 2, further comprising: a counter electrode section having a third chamber in which a counter electrode is arranged and a second liquid is supplied; and a diaphragm section having a diaphragm attached to which a diaphragm is arranged between the working electrode and the counter electrode, and which is connected to the counter electrode section and the main body section.

13. The flow cell according to claim 1, wherein the distance between the reaction field and the spectroscopic window is configured to be adjustable within a range of 0 mm to 1 mm.

14. The flow cell according to claim 1, wherein the main body further comprises a temperature control unit for adjusting the temperature of the first liquid.

15. The flow cell according to claim 1, wherein a catalyst is supported in the reaction field.

16. The flow cell according to claim 12, wherein the diaphragm is an ion exchange membrane.

17. The flow cell according to claim 2, wherein the reaction section further comprises a cylindrical section, a first fixing section detachably attached to the cylindrical section, and a second fixing section detachably attached to the first fixing section, the first fixing section and the second fixing section holding the working electrode section.

18. The flow cell according to claim 1, wherein the reaction section has a working electrode section that is positioned opposite the spectroscopic window, the working electrode comprises a first working electrode and a second working electrode connected to the first working electrode via an insulating member, and the reaction section comprises a first wiring made of a conductive material that electrically connects an external power supply unit and the first working electrode, and a second wiring made of a conductive material that electrically connects the power supply unit and the second working electrode.

19. The flow cell according to claim 18, wherein the reaction section further comprises a cylindrical section, a first fixing section detachably attached to the cylindrical section, and a second fixing section detachably attached to the first fixing section, the first wiring is provided across the cylindrical section, the first fixing section, and the second fixing section, and the second wiring is provided across the cylindrical section and the first fixing section.

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