JP2021063268A - Chemical reaction apparatus - Google Patents

Abstract

To provide a chemical reaction apparatus that enhances the efficiency of reaction.SOLUTION: A chemical reaction apparatus 100 supplies electrolyte 108 into a container 110 and reacts substances included in the electrolyte 108. In the chemical reaction apparatus 100, a reductive reaction electrode 104 and an oxidation reaction electrode 102 are arranged at such a position that they are separated facing each other in the container 110, and a plurality of sets of the reductive reaction electrode 104 and the oxidation reaction electrode 102 is arranged in the container 110.SELECTED DRAWING: Figure 2

Description

The present invention relates to a chemical reaction apparatus.

The electrode for the reduction reaction and the electrode for the oxidation reaction are separated from each other in the container so that they face each other, and the electrolytic solution is circulated between the electrode for the reduction reaction and the electrode for the oxidation reaction. A chemical reaction apparatus for chemically reacting a substrate) is disclosed (Patent Document 1). Further, a configuration in which units of a plurality of photoelectrochemical reaction cells are connected in series and in parallel is disclosed (Patent Document 2).

JP-A-2018-087074 Japanese Unexamined Patent Publication No. 2017-048442

By the way, a large electrode area is required to increase the efficiency of the chemical reaction cell. As a result, there is a problem that the chemical reaction apparatus becomes huge. Further, when the chemical reaction cells are connected in series and parallel, there is a problem that the entire apparatus becomes large due to the large number of pipes and wirings, and the manufacturing cost also increases. In addition, the flow rate of the electrolytic solution flowing through each of the chemical reaction cells tends to vary.

Further, when a voltage is applied to the chemical reaction cell from the solar cell, it is desirable that the cell can be operated at the maximum efficient operating point of the solar cell.

One aspect of the present invention is a chemical reaction apparatus that supplies a liquid into a container and reacts a substance contained in the liquid, and the reduction reaction electrode and the oxidation reaction electrode are separated from each other in the container. A plurality of sets of the reduction reaction electrode and the oxidation reaction electrode are provided in the container at opposite positions, and the reduction reaction electrode and the oxidation reaction electrode are connected in parallel, in series, or in series. It is a chemical reaction device characterized by being connected in series and parallel by combining them.

Here, the substance is carbon dioxide (CO ₂ ), and it is preferable that carbon dioxide (CO ₂ ) is reduced at the reduction reaction electrode and oxygen (O ₂ ) is generated at the oxidation reaction electrode. is there.

Further, it is preferable that an exhaust port for discharging the gas to the outside of the container and a liquid discharge port for discharging the liquid to the outside of the container are separately provided.

Further, the reduction reaction electrode and the oxidation reaction electrode are connected to the solar cell, and the output of the cell including the maximum output operating point P _{max of the} solar cell and the reduction reaction electrode and the oxidation reaction electrode. The operating point P _work satisfies the condition of (output operating point P _work / maximum output operating point P _max ) ≥ 0.8, and the light receiving area _{Asc of the} solar cell, the electrode for the reduction reaction, and the oxidation reaction are used. _{The reaction region area AE} of each of the electrodes of the reduction reaction electrode and the oxidation reaction electrode so as to satisfy the condition of 0.8 ≦ (reaction region area _AE / light receiving area A _{sc) ≦ 1.2.} It is preferable that the number of pairs is set.

Further, it is preferable that at least one of the reduction reaction electrode and the oxidation reaction electrode includes a substrate on which a catalyst is supported on both sides.

Further, it is preferable that the substrate has transparent conductive layers on both sides and the catalyst is supported on the transparent conductive layer.

Further, it is preferable that the substrate is made of a conductive material and the catalyst is supported on the conductive material.

Further, it is preferable to have a connection switching means for switching the reduction reaction electrode and the oxidation reaction electrode to a parallel connection, a series connection, or a series-parallel connection in which they are combined.

According to the present invention, it is possible to provide a chemical reaction apparatus having improved reaction efficiency.

It is a perspective view which shows the structure of the chemical reaction apparatus in embodiment of this invention. It is sectional drawing which shows the structure of the chemical reaction apparatus in embodiment of this invention. It is sectional drawing which shows the structure of the chemical reaction apparatus in embodiment of this invention. It is a figure which shows the structure of the electrode for reduction reaction in embodiment of this invention. It is a figure which shows the structure of the electrode for oxidation reaction in embodiment of this invention. It is a figure which shows the stack structure of the electrode for oxidation reaction and the electrode for reduction reaction in embodiment of this invention. It is a figure explaining the connection method of the bias power source in embodiment of this invention. It is a figure explaining the operation of the bias power source in embodiment of this invention. It is a figure which shows the example of the overflow port in embodiment of this invention. It is a figure which shows the way of providing the overflow port in embodiment of this invention. It is a schematic diagram which shows the structure of the orifice plate in embodiment of this invention. It is an enlarged schematic view which shows the structure of the orifice plate in embodiment of this invention. It is a schematic diagram which shows the structure of the chemical reaction apparatus in Example 1. FIG. It is a figure which shows the time-dependent change of the current density when the reduction reaction of carbon dioxide is repeated in Example 1. FIG. It is a figure which shows the simulation result of the flow rate distribution of the electrolytic solution in Example 2. It is a figure which shows the time change of the pressure and the flow rate of the electrolytic solution when the state which irradiated light and the state which did not irradiate a solar cell in Example 2 are repeated. It is a figure which shows the simulation result of the flow rate distribution of the electrolytic solution in the comparative example 1. FIG. It is a figure which shows the time change of the pressure and the flow rate of the electrolytic solution when the state which irradiated light and the state which did not irradiate a solar cell are repeated. It is a figure which shows the simulation result of the flow rate distribution of the electrolytic solution in the comparative example 2. It is a figure which shows the simulation result of the flow rate distribution of the electrolytic solution in Example 7. It is a figure which shows the simulation result of the flow rate distribution of the electrolytic solution in Example 9. It is a figure which shows the flow rate of the electrolytic solution in each flow path in Example 7 and Example 9. It is a figure for demonstrating each flow path in Comparative Example 3 and Example 3 to Example 9. It is a figure which shows the in-plane flow rate distribution in Comparative Example 3 and Example 3 to Example 9.

The chemical reaction apparatus 100 according to the embodiment of the present invention includes an oxidation reaction electrode 102, a reduction reaction electrode 104, a separator 106, and an electrolytic solution, as shown in a schematic perspective view of FIG. 1 and a schematic cross-sectional view of FIGS. It includes 108, a container 110 and an orifice plate 112.

FIG. 2 shows a cross-sectional view of the chemical reaction apparatus 100 cut in the YY plane in a state where the electrolytic solution 108 is not supplied. FIG. 3 shows a cross-sectional view of the chemical reaction apparatus 100 in a state where the electrolytic solution 108 is supplied, cut in the YY plane.

The oxidation reaction electrode 102 and the reduction reaction electrode 104 are plate-shaped members extending in the X direction and the Z direction, respectively, and are arranged so as to face each other along the Y direction. In the present embodiment, the oxidation reaction electrode 102 and the reduction reaction electrode 104 are arranged so that the reaction surfaces spread in the XX plane direction on which the catalysts are supported are opposed to each other with the separator 106 interposed therebetween. ..

Further, in the present embodiment, the oxidation reaction electrode 102, the separator 106 and the reduction reaction electrode 104 are arranged along the Y direction from the left side of FIGS. 2 and 3, and then the reduction reaction electrode 104, the separator 106 and the oxidation are arranged. The reaction electrode 102 is arranged along the Y direction, then the oxidation reaction electrode 102, the separator 106 and the reduction reaction electrode 104 are arranged along the Y direction, and then the reduction reaction electrode 104, the separator 106 and the oxidation. The reaction electrode 102 is arranged along the Y direction, and then the oxidation reaction electrode 102, the separator 106 and the reduction reaction electrode 104 are arranged along the Y direction. That is, a plurality of sets of electrodes including the oxidation reaction electrode 102, the separator 106, and the reduction reaction electrode 104 are stacked along the Y direction.

The reduction reaction electrode 104 is an electrode used for reducing a substance by a reduction reaction. The reduction reaction electrode 104 is formed on the substrate 114 as shown in the cross-sectional view of FIG. The reduction reaction electrode 104 includes a conductive layer 10 and a reduction catalyst layer 12.

The substrate 114 is a member that structurally supports the reduction reaction electrode 104. The material of the substrate 114 is not particularly limited, but is, for example, a glass substrate or the like. Further, the substrate 114 may include, for example, a metal or a semiconductor. The metal used as the substrate 114 is not particularly limited, but is titanium (Ti), silver (Ag), gold (Au), copper (Cu), zinc (Zn), indium (In), and cadmium (Cd). ), Tin (Sn), palladium (Pd), and lead (Pb) are preferably contained. The semiconductor used as the substrate 114 is not particularly limited, but is limited to titanium oxide (TiO ₂ ), tin oxide (SnO ₂ ), silicon (Si), strontium titanate (SrTiO ₃ ), zinc oxide (ZnO), and the like. It is preferable to use tantalum oxide (Ta ₂ O _{5) or the like.}

When the substrate 114 is used as an insulator, the conductive layer 10 is provided between the substrate 114 and the reduction catalyst layer 12. The conductive layer 10 is provided to apply a voltage to the reduction catalyst layer 12 of the reduction reaction electrode 104. The conductive layer 10 is not particularly limited, but it is preferably a transparent conductive layer such as indium tin oxide (ITO), fluorine-doped tin oxide (FTO), and zinc oxide (ZnO). In particular, considering thermal and chemical stability, it is preferable to use fluorine-doped tin oxide (FTO).

The reduction catalyst layer 12 is made of a material having a reduction catalyst function. The reduction catalyst layer 12 preferably contains a complex catalyst. The reduction catalyst layer 12 is preferably a ruthenium complex, for example. Complex catalysts include, for example, [Ru {4,4'-di (1-H-1-pyrrolipolycarbonate) -2,2'-bipyridine} (CO) (MeCN) Cl ₂ ], [Ru {4,4'. -Di (1-H-1-pyridypropyl carbonate) -2,2'-bipyridine} (CO) ₂ Cl ₂ ], [Ru {4,4'-di (1-H-1-pyrrorypolycarbonate) -2, 2'-bipyridine} (CO) ₂ ] _n , [Ru {4,4'-di (1-H-1-pyrrolipolycarbonate) -2,2'-bipyridine} (CO) (CH ₃ CN) Cl ₂ ] And so on.

Modification with a complex catalyst can be made by applying a solution of the complex in an acetonitrile (MeCN) solution onto the conductive layer 10. Further, the modification with a complex catalyst can also be performed by an electrolytic polymerization method. Electrode conductive layer 10 as a working electrode, a glass substrate coated with fluorine-containing tin oxide counter electrode (FTO), using the Ag / Ag ⁺ electrode as a reference electrode, with respect to Ag / Ag ⁺ electrode in an electrolytic solution containing complex catalyst The surface of the conductive layer 10 can be modified with a complex catalyst by passing a cathode current so as to have a negative voltage and then passing an ^{anode current so as to have a positive potential with respect to the Ag / Ag + electrode.} Acetonitrile (MeCN) can be used as the electrolyte solution, and Tetrabutylamoneiumperchlate (TBAP) can be used as the electrolyte.

Further, the reduction catalyst layer 12 can be configured to include a conductor containing a carbon material (C). It is preferable that the size of the carbon material structure alone is 1 nm or more and 1 μm or less. The carbon material preferably contains, for example, at least one of carbon nanotubes, graphene and graphite. For graphene and graphite, the size is preferably 1 nm or more and 1 μm or less. If it is a carbon nanotube, it is preferable that the diameter is 1 nm or more and 40 nm or less. The conductor can be formed by applying a carbon material mixed with a liquid such as ethanol by spraying and heating. Instead of spraying, it may be applied by spin coating. Alternatively, the solution may be directly dropped, dried and applied without using spin coating.

The method for supporting the reduction catalyst in the reduction catalyst layer 12 is as follows, for example, a solution in which a metal complex (catalyst) is dissolved in an acetonitrile (MeCN) solution (for example, a Ru complex polymer solution) is placed on a carbon-based material such as carbon paper or carbon cloth. It can be produced by applying to and drying. Further, the reduction catalyst can be supported by an electrolytic polymerization method. For example, the electrodes of the carbon-based material as a working electrode, a glass substrate coated with fluorine-containing tin oxide (FTO) on the counter electrode, using Ag / Ag ⁺ electrode as a reference electrode, Ag / Ag ⁺ electrode in an electrolytic solution containing a reducing catalyst After a cathode current is passed so as to have a negative voltage with respect to the electrode, an anode current is passed so as to have a positive potential with respect to the ^{Ag / Ag + electrode, so that the carbon-based material can be supported by a reduction catalyst.} For the solution of the electrolyte, for example, acetonitrile (MeCN) can be used, and for the electrolyte, for example, Tetrabutylammioniumperchlate (TBAP) can be used.

Although FIG. 4 shows an example in which the conductive layer 10 and the reduction catalyst layer 12 are formed on only one surface of the substrate 114, the conductive layer 10 and the reduction catalyst layer 12 are formed on both surfaces of the substrate 114. May be good.

The oxidation reaction electrode 102 is an electrode used for oxidizing a substance by an oxidation reaction. The oxidation reaction electrode 102 is formed on the substrate 116 as shown in the cross-sectional view of FIG. The oxidation reaction electrode 102 includes a conductive layer 14 and an oxidation catalyst layer 16.

The substrate 116 is a member that structurally supports the oxidation reaction electrode 102. The substrate 116 can be made of the same material as the substrate 114 used for the reduction reaction electrode 104.

The conductive layer 14 is provided in order to effectively collect current in the oxidation reaction electrode 102. The conductive layer 14 is not particularly limited, but is preferably indium tin oxide (ITO), fluorine-doped tin oxide (FTO), zinc oxide (ZnO), or the like. In particular, considering thermal and chemical stability, it is preferable to use fluorine-doped tin oxide (FTO).

The oxidation catalyst layer 16 is composed of a material having an oxidation catalyst function. The material having an oxidation catalyst function can be, for example, a material containing iridium oxide (IrOx). Iridium oxide can be supported on the surface of the conductive layer 14 as a nanocolloidal solution (T. Arai et.al, Energy Environ. Sci 8, 1998 (2015)).

For example, iridium oxide (IrOx) nanocolloids are synthesized. First, a yellow solution adjusted to pH 13 by adding a 10 wt% sodium hydroxide (NaOH) aqueous solution to 50 ml of a 2 mM potassium (IV) chloride (K ₂ IrCl _{6) aqueous solution was prepared at 90 ° C. by 20 using a hot stirrer.} Heat for minutes. The blue solution thus obtained is cooled with ice water for 1 hour. _{Then, 3M nitric acid (HNO 3} ) is added dropwise to the cooled solution (20 ml) to adjust the pH to 1, and the mixture is stirred for 80 minutes to obtain a nanocolloidal aqueous solution of iridium oxide (IrOx). Further, a 1.5 wt% NaOH aqueous solution (1-2 ml) is added dropwise to this solution to adjust the pH to 12. The nanocolloidal aqueous solution of iridium oxide (IrOx) thus obtained is applied onto the conductive layer 14 at pH 12, held at 60 ° C. for 40 minutes in a drying oven, and dried. After drying, the precipitated salt can be washed with ultrapure water to form the oxidation reaction electrode 102. The application and drying of the nanocolloidal aqueous solution of iridium oxide (IrOx) may be repeated a plurality of times.

Although FIG. 5 shows an example in which the conductive layer 14 and the oxidation catalyst layer 16 are formed on only one surface of the substrate 116, the conductive layer 14 and the oxidation catalyst layer 16 are formed on both surfaces of the substrate 116. May be good.

The separator 106 is a member that partitions between the oxidation reaction electrode 102 and the reduction reaction electrode 104. The separator 106 can be composed of a proton conductive film which is a porous body capable of transmitting protons in the electrolytic solution 108. Alternatively, a porous hydrophilic polymer material or a porous polymer material whose surface has been hydrophilized, for example, rayon non-woven fabric, vinylon non-woven fabric, hydrophilic ultra-high molecular weight polyethylene porous film, hydrophilic polypropylene mesh, etc. It can be composed of a hydrophilic ultra-high molecular weight polyethylene porous film.

The chemical reaction apparatus 100 functions by introducing an electrolytic solution 108 between the reduction reaction electrode 104 and the oxidation reaction electrode 102. That is, as shown in FIGS. 1 and 3, the container 110 is arranged so as to surround the reduction reaction electrode 104 and the oxidation reaction electrode 102, and the reactants are formed on the surfaces of the reduction reaction electrode 104 and the oxidation reaction electrode 102. The dissolved electrolytic solution 108 is supplied.

The reaction substrate can be a carbon compound, for example carbon dioxide (CO ₂ ). Further, the electrolytic solution 108 is preferably a phosphate buffered aqueous solution or a boric acid buffered aqueous solution. In a specific configuration example, _{a tank of carbon dioxide (CO 2} ) saturated phosphate buffer is provided, and the liquid is supplied to the surfaces of the reduction reaction electrode 104 and the oxidation reaction electrode 102 from the electrolytic solution supply port by a pump. , Formic acid (HCOOH) generated by the reduction reaction is recovered from the electrolytic solution discharge port 110b to an external fuel tank via the overflow port 110e, and at the same time, oxygen (O ₂ ) generated by the oxidation reaction is discharged from the exhaust port 110c. To do.

In the present embodiment, the oxidation reaction electrode 102 and the reduction reaction electrode 104 are arranged in the container 110 so that the reaction surface on which the catalyst is supported is in the vertical direction (XZ plane inward direction). Further, in the present embodiment, a plurality of sets 120 of the oxidation reaction electrode 102 and the reduction reaction electrode 104 are stacked along the Y direction.

6 (a) to 6 (d) show a configuration example in which a plurality of sets 120 of the oxidation reaction electrode 102 and the reduction reaction electrode 104 are stacked. In FIGS. 6A to 6D, the separator 106 is omitted and only the oxidation reaction electrode 102, the reduction reaction electrode 104, and the container 110 are cut in the XY plane in order to avoid complication. The cross-sectional view is schematically shown.

As shown in FIG. 6A, the containers 110 in which each set 120 is housed can be stacked. Further, as shown in FIG. 6B, the back surfaces of the oxidation reaction electrodes 102 of the adjacent group 120 are bonded to each other, and the back surfaces of the reduction reaction electrodes 104 are bonded to each other, so that the oxidation reaction electrode 102 and the reduction reaction are bonded to each other. It is also possible to stack the electrode 104 for the reduction reaction, the electrode 104 for the reduction reaction, the electrode 102 for the oxidation reaction, and the like and store them in one container 110. Further, as shown in FIGS. 6 (c) and 6 (d), oxidation catalyst layers 16 are formed on both surfaces of the substrates 116 of the oxidation reaction electrodes 102 of the adjacent sets 120, and the substrates 114 of the reduction reaction electrodes 104 are formed. A reduction catalyst layer 12 is formed on both sides of the above, and the oxidation reaction electrode 102, the reduction reaction electrode 104, the reduction reaction electrode 104, the oxidation reaction electrode 102, and the like are stacked and stored in one container 110. You can also do it. Note that FIG. 6C shows a configuration in which the reduction catalyst layer 12 and the oxidation catalyst layer 16 are supported after the conductive layers 10 are formed on both surfaces of the substrates 114 and 116 as glass substrates. The glass substrate has a thickness of, for example, about several mm from the viewpoint of mechanical strength and the like. Further, FIG. 6D shows a configuration in which the substrates 114 and 116 are metal substrates (for example, titanium) and the reduction catalyst layer 12 and the oxidation catalyst layer 16 are supported on both sides. The metal substrate can have a thickness of, for example, about 1 mm.

In this way, as shown in FIGS. 6 (b) to 6 (d), the oxidation reaction electrode 102 and the reduction reaction electrode 104 are stacked and stored in one container, as shown in FIG. 6 (a). The area of the reaction region of the oxidation reaction electrode 102 and the reduction reaction electrode 104 per volume of the chemical reaction apparatus 100 is larger than that in the case where the containers containing the individual oxidation reaction electrodes 102 and the reduction reaction electrode 104 are stacked. It can be made larger.

Further, it is preferable that the reduction reaction electrode 104 and the oxidation reaction electrode 102 are electrically connected to each other so that an appropriate bias voltage is applied. The means for applying the bias voltage is not particularly limited, and examples thereof include chemical batteries (including primary batteries, secondary batteries, etc.), constant voltage sources, solar cells, and the like. At this time, the positive electrode is connected to the oxidation reaction electrode 102, and the negative electrode is connected to the reduction reaction electrode 104.

When a solar cell is adopted as the bias power source, the solar cell can be arranged adjacent to the oxidation reaction electrode 102 and the reduction reaction electrode 104. For example, the solar cell may be arranged on the back surface of the reduction reaction electrode 104, the positive electrode of the solar cell may be connected to the oxidation reaction electrode 102, and the negative electrode may be connected to the reduction reaction electrode 104.

When synthesizing formic acid (HCOOH) or the like from carbon dioxide (CO _{2 ), water (H 2} O) is oxidized to supply electrons and protons to _{carbon dioxide (CO 2).} At around pH 7, _{the oxidation potential of water (H 2} O) is 0.82 V, and the reduction potential is −0.41 V (both are NHE). The reduction potentials of carbon dioxide (CO ₂ ) to carbon monoxide (CO), formic acid (HCOOH), and methyl alcohol (CH ₃ OH) are -0.53V, -0.61V, and -0.38V, respectively. .. Therefore, the potential difference between the oxidation potential and the reduction potential is 1.20 to 1.43 V.

7 (a) to 7 (c) show an example of a method of connecting a bias power supply when a set of an oxidation reaction electrode 102 and a reduction reaction electrode 104 is stacked. FIG. 7A shows an example in which the bias power supplies are connected in parallel in a configuration in which the back surfaces of the reduction reaction electrodes 104 and the back surfaces of the oxidation reaction electrodes 102 are laminated and stacked. Further, the same configuration can be obtained in a configuration in which the reduction catalyst layer 12 and the oxidation catalyst layer 16 are formed and stacked on the surfaces of the non-conductive substrates 114 and 116. FIG. 7B shows an example in which the bias power supply is connected in parallel in a configuration in which the reduction catalyst layer 12 and the oxidation catalyst layer 16 are formed and stacked on the surfaces of the conductive substrates 114 and 116. FIG. 7C shows an example in which the bias power supply is connected so that the configuration in which the oxidation reaction electrode 102 and the reduction reaction electrode 104 are alternately stacked is connected in series.

When the bias power source is a solar cell, if the pair of the oxidation reaction electrode 102 and the reduction reaction electrode 104 is used alone, it will be used at an operating point where the efficiency of the solar cell is poor, as shown in FIG. On the other hand, when a plurality of sets of the oxidation reaction electrode 102 and the reduction reaction electrode 104 are connected in parallel, the solar cell can be used at an efficient operating point as shown in FIG.

The connection configuration of the bias power supply to the oxidation reaction electrode 102 and the reduction reaction electrode 104 is not limited to these examples. For example, a part of the oxidation reaction electrode 102 and the reduction reaction electrode 104 may be connected in series, parallel or series-parallel. Further, a switch for switching the connection may be provided so that the connection configuration of the oxidation reaction electrode 102 and the reduction reaction electrode 104 to the bias power supply can be changed.

Further, it is preferable to set the characteristics and the reaction region area of the oxidation reaction electrode 102 and the reduction reaction electrode 104 in relation to the characteristics of the solar cell and the light receiving area. The maximum output operating point P _max of the solar cell when the intensity of the light (for example, sunlight) irradiated to the solar cell is 1 kW / m ² , and the output operating point P of the chemical reactor 100 determined when the solar cell is connected. it is preferable that the relationship of the _work is set to be _P work _{/ P max} ≧ 0.8. _{Further, oxidation is performed so that the reaction region areas A E} of each of the oxidation reaction electrode 102 and the reduction reaction electrode 104 are 0.8 ≤ A _E / A _sc ≤ 1.2 with respect to the light receiving area A _{sc of the solar cell.} It is preferable to set the number of stacks of the set of the reaction electrode 102 and the reduction reaction electrode 104.

When _{the relationship of A E} / A _sc > 1.2 is satisfied, the reaction region areas of the oxidation reaction electrode 102 and the reduction reaction electrode 104 for the solar cell become excessive, resulting in insufficient operating capacity of the solar cell and chemistry. The capacity of the reactor 100 cannot be fully exerted. Further, in this case, the size of the chemical reaction apparatus 100 becomes unnecessarily large. On the other hand, _{when the relationship of 0.8> A E} / _Asc , the area of each reaction region of the oxidation reaction electrode 102 and the reduction reaction electrode 104 for the solar cell becomes too small, and the capacity of the solar cell is effectively utilized. Not done.

The container 110 is a member that supports the oxidation reaction electrode 102, the reduction reaction electrode 104, and the separator 106, and constitutes a flow path through which the electrolytic solution 108 flows. The container 110 is made of a material having the mechanical strength required to form the chemical reaction apparatus 100 as a cell. For example, the container 110 can be made of metal, plastic, or the like.

The container 110 is provided with an electrolytic solution supply port 110a for supplying the electrolytic solution 108 into the container 110. Further, an electrolytic solution discharge port 110b for discharging the electrolytic solution 108 from the inside of the container 110 is provided. That is, the electrolytic solution 108 containing the substance for reaction is supplied from the electrolytic solution supply port 110a into the container 110, and the electrolytic solution 108 is circulated in the reaction region between the oxidation reaction electrode 102 and the reduction reaction electrode 104. After that, the electrolytic solution 108 is discharged to the outside of the container 110 from the electrolytic solution discharge port 110b.

Further, the container 110 is provided with an exhaust port 110c for discharging the gas generated by the reaction in the chemical reaction apparatus 100 from the container 110. In the container 110, it is preferable to arrange the exhaust port 110c above the reaction region in which the oxidation reaction electrode 102 and the reduction reaction electrode 104 are arranged in the vertical direction.

Further, the container 110 is provided with an overflow port 110e for guiding the electrolytic solution 108 to the electrolytic solution discharge port 110b. The overflow port 110e is a structure for overflowing the electrolytic solution 108 when the electrolytic solution 108 supplied into the container 110 exceeds a certain amount. An overflow wall 110d is provided in the container 110 to partition the region where the oxidation reaction electrode 102 and the reduction reaction electrode 104 are arranged and the electrolytic solution discharge port 110b, and the upper end of the overflow wall 110d in the vertical direction (Z direction). Can form the overflow port 110e by forming an opening for overflowing the electrolytic solution 108 to the electrolytic solution discharge port 110b. The overflow port 110e is provided at a position lower than the exhaust port 110c along the vertical direction (Z direction).

At this time, it is preferable that the upper end portion of the overflow wall 110d in the vertical direction (Z direction) is higher than the upper end portion of the oxidation reaction electrode 102 and the reduction reaction electrode 104 in the vertical direction (Z direction). is there. As a result, the electrolytic solution 108 can be overflowed from the overflow port 110e in a state where the entire oxidation reaction electrode 102 and the reduction reaction electrode 104 are immersed in the electrolytic solution 108.

In the present embodiment, the gas generated in the electrolytic solution 108 by the reaction is separated from the electrolytic solution 108 by providing an overflow port 110e for discharging the electrolytic solution 108 from the container 110 separately from the exhaust port 110c. The gas can be discharged from the exhaust port 110c, and the electrolytic solution 108 can be discharged from the electrolytic solution discharge port 110b via the overflow port 110e.

The overflow port 110e can be a single rectangular slot, as shown in FIG. 9A. Further, as shown in FIG. 9B, the overflow port 110e may have a configuration in which a plurality of rectangular elongated holes are arranged side by side. Further, as shown in FIG. 9C, the overflow port 110e may have a configuration in which a plurality of circular holes are arranged side by side. However, the overflow port 110e is not limited to these configuration examples.

As shown in the enlarged view of the XZ plane in FIG. 10, the overflow port 110e is connected to the reaction surface X that causes a reaction to generate gas at the oxidation reaction electrode 102 and the reduction reaction electrode 104 at the shortest distance. It is preferable to provide the line Y so that the angle θ formed by the line Z in the vertical direction (Z direction) is 30 ° or less.

By arranging the overflow port 110e in this way, the electrolytic solution 108 can be supplied substantially uniformly to the entire reaction surface of the oxidation reaction electrode 102 and the reduction reaction electrode 104.

Further, the chemical reaction apparatus 100 is provided with an orifice plate 112. The orifice plate 112 is a plate-shaped member provided with orifice holes 112a and 112b which are through holes for limiting the flow of the electrolytic solution 108 introduced into the container 110 from the electrolytic solution supply port 110a. The orifice plate 112 is arranged on the flow path from the electrolytic solution supply port 110a to the region where the oxidation reaction electrode 102 and the reduction reaction electrode 104 are provided in the container 110. The orifice plate 112 is made of a material having the required mechanical strength. For example, the orifice plate 112 can be made of metal, plastic, or the like.

FIG. 11 is a schematic view showing the configuration of the orifice plate 112. FIG. 11 is a view in which the cross section of the main portion of the XY plane of the chemical reaction apparatus 100 is viewed from above to below in the Z direction. FIG. 12 is a partially enlarged view of the area surrounded by the broken line in FIG.

The oxidation reaction electrode 102, the reduction reaction electrode 104, and the separator 106 extend in the XZ plane, and the separator 106 is arranged between the oxidation reaction electrode 102 and the reduction reaction electrode 104. In the example of FIG. 11, five sets of the oxidation reaction electrode 102, the separator 106, and the reduction reaction electrode 104 are stacked along the Y direction.

In the chemical reaction apparatus 100, the space formed by the oxidation reaction electrode 102 and the separator 106 and the space formed by the reduction reaction electrode 104 and the separator 106 serve as a flow path for flowing the electrolytic solution 108. The orifice plate 112 is arranged between the electrolyte supply port 110a and these flow paths. The orifice plate 112 is formed by an orifice hole 112a connecting the flow path formed by the oxidation reaction electrode 102 and the separator 106 and the electrolytic solution supply port 110a, and the reduction reaction electrode 104 and the separator 106. An orifice hole 112b is provided that connects the flow path and the electrolytic solution supply port 110a. The diameters of the orifice holes 112a and 112b may be, for example, 0.5 mm, and the spacing may be, for example, 10 mm.

Therefore, the electrolytic solution 108 supplied from the electrolytic solution supply port 110a is stored in the space from the electrolytic solution supply port 110a to the orifice plate 112, and then undergoes a reduction reaction with the oxidation reaction electrode 102 via the orifice holes 112a and 112b. It is ejected into the flow path between the electrode 104 and the electrode 104. When the electrolytic solution 108 flows into the flow path between the oxidation reaction electrode 102 and the reduction reaction electrode 104, the flow path is filled with the electrolytic solution 108. Further, when the amount of the electrolytic solution 108 exceeds the edge of the overflow port 110e, the electrolytic solution 108 flows from the overflow port 110e into the electrolytic solution discharge port 110b and is discharged from the container 110.

Here, the ratio of the total area of the orifice holes 112a and 112b to the area of the cross section perpendicular to the flow direction of the electrolytic solution 108 (here, the Z direction) in the flow path through which the electrolytic solution 108 flows is set to 0.3% or more and 9% or less. It is preferable to do so. Further, the ratio of the total area of the orifice holes 112a and 112b to the area of the cross section perpendicular to the flow direction of the electrolytic solution 108 (here, the Z direction) in the flow path through which the electrolytic solution 108 flows is 1.4% or more and 3.6% or less. Is more preferable. By appropriately narrowing the area of the orifice holes 112a and 112b with respect to the flow path area in this way, the flow of the electrolytic solution 108 in the flow path formed between the oxidation reaction electrode 102 and the reduction reaction electrode 104. Can be made uniform.

Further, it is preferable that the ratio of the total area of the orifice holes 112a and 112b to the total area of the electrolytic solution supply port 110a for supplying the electrolytic solution 108 is 20% or more and 126% or less. Further, it is more preferable that the ratio of the total area of the orifice holes 112a and 112b to the total area of the electrolytic solution supply port 110a for supplying the electrolytic solution 108 is 20% or more and 50% or less. As a result, the flow of the electrolytic solution 108 in the flow path formed between the oxidation reaction electrode 102 and the reduction reaction electrode 104 can be further made uniform.

The ratio of the total area of the orifice holes 112a and 112b to the area perpendicular to the flow direction of the electrolytic solution 108 in the flow path through which the electrolytic solution 108 flows and the total area of the orifice holes 112a and 112b to the total area of the electrolytic solution supply port 110a. The flow of the electrolytic solution 108 can be made more uniform by satisfying either one of the ratio conditions. However, by satisfying both conditions at the same time, the flow of the electrolytic solution 108 can be made more uniform.

Further, it is preferable that the pore diameters of the orifice holes 112a and 112b increase as the distance from the electrolytic solution supply port 110a increases. That is, when the pore diameters of the orifice holes 112a and 112b are made uniform, the flow rate of the electrolytic solution 108 tends to decrease as the distance from the electrolytic solution supply port 110a increases. By increasing the hole diameters of the orifice holes 112a and 112b, the flow rate distribution of the electrolytic solution 108 can be made more uniform.

For example, it is preferable to increase the hole diameters of the orifice holes 112a and 112b in proportion to the distance from the electrolyte supply port 110a. Further, for example, it is preferable to increase the hole diameters of the orifice holes 112a and 112b in proportion to the square of the distance from the electrolytic solution supply port 110a.

Further, it is preferable that the distance between the orifice holes 112a and 112b becomes smaller as the distance from the electrolytic solution supply port 110a increases. That is, when the distance between the orifice holes 112a and 112b is made uniform, the flow rate of the electrolytic solution 108 tends to decrease as the distance from the electrolytic solution supply port 110a increases. Therefore, as the distance from the electrolytic solution supply port 110a increases. By reducing the distance between the orifice holes 112a and 112b, the flow rate distribution of the electrolytic solution 108 can be made more uniform.

For example, it is preferable to reduce the distance between the orifice holes 112a and 112b in proportion to the distance from the electrolyte supply port 110a. Further, for example, it is preferable to reduce the distance between the orifice holes 112a and 112b in proportion to the square of the distance from the electrolytic solution supply port 110a.

The water of the electrolytic solution 108 is oxidized on the reaction surface of the oxidation reaction electrode 102, whereas the substance contained in the electrolytic solution 108 is reduced on the reaction surface of the reduction reaction electrode 104. Then, the ions are exchanged via the separator 106. Therefore, the water required for the oxidation reaction performed in the oxidation reaction electrode 102 is sufficiently supplied. Further, it is preferable that a sufficient amount of the substance required for the reduction reaction performed in the reduction reaction electrode 104 is also supplied. Therefore, the total area of the orifice holes 112b provided for the flow path formed by the reduction reaction electrode 104 and the separator 106 is provided for the flow path formed by the oxidation reaction electrode 102 and the separator 106. It is preferable that the area is larger than the total area of the orifice holes 112a.

For example, when the reaction substrate contained in the electrolytic solution 108 is carbon dioxide (CO ₂ ), the reduction reaction can be carried out by increasing the amount of _{carbon dioxide (CO 2} ) supplied to the reaction surface of the reduction reaction electrode 104. Efficiency can be improved.

Specifically, the total area of the orifice hole 112b is preferably 4 times or more and 9 times or less the total area of the orifice hole 112a. By setting the ratio of the total area of the orifice holes 112a and the orifice holes 112b to the above range, the efficiency of the reduction reaction can be further improved.

In the present embodiment, the separator 106 is provided with a straightening vane 106a projecting in the Y direction. The straightening vane 106a extends along the direction from the electrolytic solution supply port 110a to the overflow port 110e (here, the Z direction), and the electrolytic solution along the direction intersecting the direction (here, the X direction). Limit the flow of 108. As a result, the flow of the electrolytic solution 108 can be adjusted in the direction from the electrolytic solution supply port 110a to the overflow port 110e (here, the Z direction).

In the example of FIG. 11, six straightening vanes 106a are provided for each set of the oxidation reaction electrode 102, the separator 106, and the reduction reaction electrode 104. Therefore, the straightening vane 106a partitions the flow path formed by the oxidation reaction electrode 102 and the separator 106 and the flow path formed by the reduction reaction electrode 104 and the separator 106 into seven regions.

By providing the straightening vane 106a in this way, the flow of the electrolytic solution 108 can be kept more uniform. In particular, by combining the orifice holes 112a and 112b and the straightening vane 106a, the distribution of the flow rate of the electrolytic solution 108 along the direction intersecting the flow of the electrolytic solution 108 (here, the X direction) can be made more uniform. ..

<Example 1>
FIG. 13 is a schematic view showing a configuration example of the chemical reaction apparatus 100 in Example 1. In Example 1, a tubular manifold 130 was provided instead of the orifice plate 112. The overflow port 110e has one rectangular shape, and the angle θ formed by the line connecting the reaction surfaces of the oxidation reaction electrode 102 and the reduction reaction electrode 104 at the shortest distance and the line in the vertical direction (Z direction) is 17. It was 0 °.

IrOx (Nichigensei: Anodec 100) was used as the electrode 102 for the oxidation reaction. For the reduction reaction electrode 104, a carbon paper / multi-wall carbon nanotube in which a Ru complex polymer was supported and attached to a titanium substrate using a carbon-based adhesive was used. A set of the oxidation reaction electrode 102 and the reduction reaction electrode 104 was arranged in the container 110 with the reaction surfaces carrying the catalyst facing each other. A voltage of 1.8 V was applied to the oxidation reaction electrode 102 and the reduction reaction electrode 104 using a DC power supply. No separator 106 or straightening vane was provided. The electrolytic solution 108 was _{a 0.4 M phosphate buffer solution in which CO 2} was saturated and dissolved by bubbling in another container, and was supplied from a cylindrical tubular manifold 130 using a pump.

In this embodiment, although a rectifying plate for controlling the flow of the electrolytic solution 108 is not provided, gas bubbles generated in the entire flow path between the oxidation reaction electrode 102 and the reduction reaction electrode 104. Was confirmed to move from the manifold 130 toward the overflow port 110e along the X direction at the same speed at any location. That is, the flow velocity of the electrolytic solution 108 was constant in the entire flow path between the oxidation reaction electrode 102 and the reduction reaction electrode 104.

FIG. 14 shows the change with time of the current density when the reduction reaction of carbon dioxide is repeated in Example 1. Here, a process of continuously applying a voltage (1.8 V) between the oxidation reaction electrode 102 and the reduction reaction electrode 104 for 30 minutes and stopping the voltage application every 30 minutes is performed four times (# 1 to # 1). # 4) The change over time in the current density when repeated was shown. In FIG. 14, it is understood that the oxidation reaction electrode 102 and the reduction reaction electrode 104 did not deteriorate because the four changes of the current density with time completely overlapped with each other.

<Example 2>
Example 2 is a configuration example of the chemical reaction apparatus 100 shown in FIGS. 1 to 3. In the second embodiment, the overflow port 110e has one rectangular shape, and is formed by a line connected to the reaction surface of the oxidation reaction electrode 102 and the reduction reaction electrode 104 at the shortest distance and a line in the vertical direction (Z direction). The angle θ was set to 0. That is, an overflow port 110e was formed on the entire reaction surface of the oxidation reaction electrode 102 and the reduction reaction electrode 104 in the X direction.

As the electrode 102 for the oxidation reaction, one in which IrOx colloid was supported on a glass substrate on which _{SnO 2: F (FTO) was formed was used.} As the electrode 104 for the reduction reaction, a carbon paper / multi-wall carbon nanotube on which a Ru complex polymer was supported was used. The size of the oxidation reaction electrode 102 and the reduction reaction electrode 104 was 360 mm square. The electrolytic solution 108 was _{a 0.4 M phosphate buffer solution in which CO 2} was saturated and dissolved by bubbling in another container, and was supplied from the electrolytic solution supply port 110a via the orifice plate 112. As shown in the example of FIG. 11, the oxidation reaction electrode 102 and the reduction reaction electrode 104 were arranged in a stack of 5 sets in the container 110 with the reaction surfaces carrying the catalyst facing each other.

The separator 106 and the straightening vane 106a were also arranged. The space formed by the oxidation reaction electrode 102 and the separator 106 and the space formed by the reduction reaction electrode 104 and the separator 106 were used as flow paths for the electrolytic solution 108 to flow. In the orifice plate 112, the orifice hole 112a on the oxidation reaction electrode 102 side has a hole diameter φ = 1 mm, and the orifice hole 112b on the reduction reaction electrode 104 side has a hole diameter φ = 1.5 mm. Further, as shown in FIGS. 11 and 13, in each flow path separated by the straightening vane 106a, one orifice hole 112a on the oxidation reaction electrode 102 side is provided with respect to one orifice hole 112b on the reduction reaction electrode 104 side. Was arranged.

Six crystalline silicon solar cells were connected in series as a DC power source to the oxidation reaction electrode 102 and the reduction reaction electrode 104, and a voltage was applied.

FIG. 15 shows the result of simulating the flow rate distribution of the electrolytic solution 108 in Example 2 using fluid analysis software (Solidworks). The flow rate of the electrolytic solution 108 is substantially uniform in any direction of the flow path in the container 110, and its distribution [(maximum value of flow rate-average value of flow rate) / (average value of flow rate)] is 6. It was .14%.

FIG. 16 is a diagram showing changes in the pressure of the container 110 and the flow rate of the electrolytic solution in Example 2. That is, it shows the time change of the pressure and the flow rate of the electrolytic solution 108 in the container 110 when the solar cell is irradiated with light (ON state) and not irradiated (OFF state). When light is irradiated, an oxidation reaction of water (H _{2 O) occurs at the oxidation reaction electrode 102 and a carbon dioxide (CO 2} ) reduction reaction occurs at the reduction reaction electrode 104, so that oxygen (O ₂ ) bubbles occur. Occurs. However, in the second embodiment, the generated oxygen (O ₂ ) is discharged from the exhaust port 110c, and the electrolytic solution 108 is discharged from the electrolytic solution discharge port 110b via the overflow port 110e, so that the pressure in the container 110 is increased. There was no change between the state with light and the state without light. In addition, no change in the flow rate of the electrolytic solution 108 in the container 110 was observed.

<Comparative example 1>
A set of the oxidation reaction electrode 102 and the reduction reaction electrode 104 was arranged in the container 110 with the reaction surfaces carrying the catalyst facing each other. Comparative Example 1 was a configuration in which two common discharge ports for the electrolytic solution and gas were provided on the upper surface of the container 110 instead of providing the overflow port 110e. That is, both the electrolytic solution 108 and the gas generated by the reaction are discharged from the discharge port to the outside of the container 110. The angle θ formed by the line connecting the reaction surface of the oxidation reaction electrode 102 and the reduction reaction electrode 104 and the discharge port at the shortest distance and the line in the vertical direction (Z direction) was 33.0 °.

Further, in Comparative Example 1, instead of the orifice plate 112, a cylindrical tubular manifold 130 was provided as in Example 1. The straightening vane 106a was not provided.

FIG. 17 shows the results of simulating the flow rate distribution of the electrolytic solution 108 in Comparative Example 1 using fluid analysis software (Solidworks). The electrolytic solution 108 swirled and flowed in various places in the container 110. The (maximum value of flow rate) / (minimum value of flow rate) of the electrolytic solution 108 at the evaluation position shown in the figure was almost 5 times.

<Comparative example 2>
The configuration in Comparative Example 1 was the same except that the straightening vane 106a was provided. Four crystalline silicon solar cells were connected in series as a DC power source to the oxidation reaction electrode 102 and the reduction reaction electrode 104, and a voltage was applied.

FIG. 18 shows the time change of the pressure and the flow rate of the electrolytic solution 108 in the container 110 when the state in which the solar cell is irradiated with light (ON state) and the state in which the solar cell is not irradiated (OFF state) are repeated. When irradiated with light, an oxidation reaction of water (H ₂ O) occurs at the oxidation reaction electrode 102 and a carbon dioxide (CO ₂ ) reduction reaction occurs at the reduction reaction electrode 104. _{As a result, oxygen (O 2} ) is generated at the oxidation reaction electrode 102, so that the average pressure of the electrolytic solution 108 in the container 110 rises and the flow rate of the electrolytic solution 108 fluctuates. At this time, in the upper left and right corners of the container 110, the movement of air bubbles from top to bottom was visually observed. That is, it was confirmed that there is a region in which the electrolytic solution 108 flows from top to bottom against the normal flow from bottom to top. When the light irradiation was stopped, the average pressure of the electrolytic solution 108 decreased.

In the state of being irradiated with light, the fluctuations in the pressure and the flow rate of the electrolytic solution 108 were not constant, and the vertical movement was repeated. Therefore, feedback control of the output of the pump so as to keep the supply amount of the electrolytic solution 108 constant did not function sufficiently.

FIG. 19 shows a simulation result of the flow rate distribution of the electrolytic solution 108 in Comparative Example 2. By providing the straightening vane 106a with respect to Comparative Example 1, the electrolytic solution 108 showed a substantially symmetrical distribution in the container 110. However, the flow rate of the electrolytic solution 108 at the evaluation position shown in the figure decreased to about 1/3 as the distance from the discharge port increased.

<Examples 3 to 9>
In the configuration example of the chemical reaction apparatus 100 shown in FIGS. 1 to 3, the orifice holes 112a and 112b with respect to the area of the cross section perpendicular to the flow direction (here, the Z direction) of the electrolytic solution 108 in the flow path through which the electrolytic solution 108 flows. Examples 3 to 9 were set by changing the ratio of the total area and the ratio of the total area of the orifice holes 112a and 112b to the total area of the electrolytic solution supply port 110a for supplying the electrolytic solution 108. The separator 106 and the straightening vane 106a were also arranged.

Specifically, as shown in Table 1, the ratio of the total area of the orifice holes 112a and 112b to the area of the cross section perpendicular to the flow direction of the electrolytic solution 108 (here, the Z direction) in the flow path through which the electrolytic solution 108 flows. The ratio of the total area of the orifice holes 112a and 112b to the total area of the electrolytic solution supply port 110a for supplying the electrolytic solution 108 is changed from 0.35% to 8.98% from 4.95% to 125.28%. To be changed to Example 3 to Example 9, respectively.

For Examples 3 to 9, the flow of the electrolytic solution 108 in the chemical reaction apparatus 100 was simulated using fluid analysis software (Solidworks). The flow rate at the electrolyte supply port 110a was set to 2 liters / min.

<Comparative example 3>
In the configuration example of the chemical reaction apparatus 100 shown in FIGS. 1 to 3, the orifice holes 112a and 112b with respect to the area of the cross section perpendicular to the flow direction (here, the Z direction) of the electrolytic solution 108 in the flow path through which the electrolytic solution 108 flows. Comparative Example 3 has a configuration in which the ratio of the total area is 0.09% and the ratio of the total area of the orifice holes 112a and 112b to the total area of the electrolytic solution supply port 110a for supplying the electrolytic solution 108 is 12.35%. did. The separator 106 and the straightening vane 106a were also arranged.

<Simulation result>
FIG. 20 shows the result of the simulation in Example 7. Further, FIG. 21 shows the result of the simulation performed in the ninth embodiment.

FIG. 22 is a diagram showing the flow rates of the electrolytic solution 108 in each flow path of the chemical reaction apparatus 100 in Examples 7 and 9. As shown in FIG. 23, FIG. 22 shows rows 1 to 7 separated by a rectifying plate 106a along the X direction and 1 to 5 separated by a separator 106 and a reduction reaction electrode 104 along the Y direction. The results of simulation calculation of the flow rate of the electrolytic solution 108 in each flow path in the reduction reaction electrode 104 specified by the combination of rows (indicated by the numerical values circled for convenience in the figure) are shown. In FIG. 22, the horizontal axis shows the row numbers (1 to 7) of the flow paths separated by the straightening vanes 106a along the X direction, and each line is the seventh embodiment (indicated as 0520 in the figure) and the ninth embodiment. The flow rate for each line number (1 to 5) of the flow path separated by the separator 106 and the reduction reaction electrode 104 along the Y direction in (indicated as 0517 in the figure) is shown.

In Example 7 (indicated as 0520 in the figure), the flow rate distribution was the largest in the flow path of line number 4 along the X direction, and the value of the in-plane flow rate distribution was 7.15%. In Example 9 (indicated as 0517 in the figure), the flow rate distribution was the largest in the flow path of line number 3 along the X direction, and the value of the in-plane flow rate distribution was 12.62%. Similarly, Table 1 shows the values of the in-plane flow rate distribution calculated by simulation for each of Comparative Example 3 and Examples 3 to 9.

As shown in the graph of FIG. 24, the in-plane flow rate distribution became large in both the configuration in which the ratio of the area of the orifice holes 112a and 112b to the flow path area was too small and the configuration in which the ratio was too large.

That is, the in-plane flow rate distribution of the electrolytic solution 108 can be made more uniform by setting the ratio of the total area of the orifice holes 112a and 112b to the area of the flow path through which the electrolytic solution 108 flows to be 0.3% or more and 9% or less. did it. In particular, it was found that it is more preferable to set the content to 1.4% or more and 3.6% or less. Further, by setting the ratio of the total area of the orifice holes 112a and 112b to the total area of the electrolytic solution supply port 110a to 20% or more and 126% or less, the in-plane flow rate distribution of the electrolytic solution 108 could be made more uniform. In particular, it was found that it is more preferable to set it to 20% or more and 50% or less.

As described above, by appropriately setting the areas of the orifice holes 112a and 112b, the distribution of the flow rate of the electrolytic solution 108 in the chemical reaction apparatus 100 can be made more uniform. As a result, the oxidation reaction and the reduction reaction in the chemical reaction apparatus 100 can proceed more evenly on the entire surfaces of the oxidation reaction electrode 102 and the reduction reaction electrode 104, and the reaction efficiency of the chemical reaction apparatus 100 can be improved. ..

10 Conductive layer, 12 Reduction catalyst layer, 14 Conductive layer, 16 Oxidation catalyst layer, 100 Chemical reactor, 102 Oxidation reaction electrode, 104 Reduction reaction electrode, 106 Separator, 106a rectifying plate, 108 Electrolyte, 110 container, 110a Electrolyte supply port, 110b electrolyte discharge port, 110c exhaust port, 110d overflow wall, 110e overflow port, 112 (112a, 112b) orifice plate, 114,116 substrate, 130 manifold.

Claims (8)

A chemical reaction device that supplies a liquid into a container and reacts substances contained in the liquid.
The reduction reaction electrode and the oxidation reaction electrode are arranged at positions facing each other in one container, and a plurality of sets of the reduction reaction electrode and the oxidation reaction electrode are provided in the container. A chemical reaction apparatus characterized in that the reduction reaction electrode and the oxidation reaction electrode are connected in parallel, connected in series, or connected in series and parallel in combination thereof. The chemical reaction apparatus according to claim 1.
The substance is carbon dioxide (CO ₂ ) and
A chemical reaction apparatus characterized in that carbon dioxide (CO ₂ ) is reduced at the reduction reaction electrode and oxygen (O _{2) is generated at the oxidation reaction electrode.} The chemical reaction apparatus according to claim 1 or 2.
A chemical reaction apparatus characterized in that an exhaust port for discharging the gas to the outside of the container and a liquid discharge port for discharging the liquid to the outside of the container are separately provided. The chemical reaction apparatus according to any one of claims 1 to 3.
The reduction reaction electrode and the oxidation reaction electrode are connected to a solar cell.
The maximum output operating point P _{max of the solar cell and the output operating point P work of the} cell including the reduction reaction electrode and the oxidation reaction electrode are (output operating point P _work / maximum output operating point P _max ) ≧. Satisfy the condition of 0.8,
The light receiving area A _{sc of the solar cell and the reaction region area AE} of each of the reduction reaction electrode and the oxidation reaction electrode are 0.8 ≦ (reaction region area _AE / light receiving area A _sc ) ≦ 1. A chemical reaction apparatus characterized in that the number of pairs of the reduction reaction electrode and the oxidation reaction electrode is set so as to satisfy the condition of 2. The chemical reaction apparatus according to any one of claims 1 to 4.
A chemical reaction apparatus, wherein at least one of the reduction reaction electrode and the oxidation reaction electrode includes a substrate on which a catalyst is supported on both sides. The chemical reaction apparatus according to claim 5.
The substrate has transparent conductive layers on both sides.
A chemical reaction apparatus characterized in that the catalyst is supported on the transparent conductive layer. The chemical reaction apparatus according to claim 5.
The substrate is made of a conductive material.
A chemical reaction apparatus characterized in that the catalyst is supported on the conductive material. The chemical reaction apparatus according to any one of claims 1 to 7.
A chemical reaction apparatus comprising a connection switching means for switching between the reduction reaction electrode and the oxidation reaction electrode in parallel connection, series connection, or series-parallel connection in combination thereof.

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