CN115125546A

CN115125546A - Electrochemical reaction device

Info

Publication number: CN115125546A
Application number: CN202210164544.6A
Authority: CN
Inventors: 及川博; 岛田雄太
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2021-03-11
Filing date: 2022-02-22
Publication date: 2022-09-30
Also published as: JP7176026B2; US20220290318A1; JP2022139001A

Abstract

The purpose of the present invention is to provide an electrochemical reaction device capable of electrochemically reducing carbon dioxide with high energy efficiency. In an electrochemical reaction device (10) for electrochemically reducing carbon dioxide, a first power supply body (27), a first gas flow path structure (24), a cathode (21), a liquid flow path structure (23), an ion exchange membrane (26), an anode (22), a second gas flow path structure (25), and a second power supply body (28) are sequentially laminated, an electrolyte flow path (31) is formed between the cathode (21) and the ion exchange membrane (26), a cathode-side gas flow path (32) for supplying carbon dioxide gas is formed on the side of the cathode (21) opposite to the anode (22), and an anode-side gas flow path (33) is formed on the side of the anode (22) opposite to the cathode (21).

Description

Electrochemical reaction device

Technical Field

The present invention relates to an electrochemical reaction apparatus.

Background

A technique of electrochemically reducing exhaust gas or carbon dioxide in the atmosphere to obtain valuable substances is a promising technique that has a possibility of achieving carbon neutralization, but the greatest problem is the economic efficiency. In order to improve the economy, it is important to electrolyze carbon dioxide with high energy efficiency while minimizing the loss.

Since electrolysis of water is accompanied in carbon dioxide electrolysis, a cell for carbon dioxide electrolysis requires an electrolyte solution flow path for supplying and discharging an electrolyte solution (aqueous solution) in addition to a gas flow path for supplying carbon dioxide and discharging a gaseous product generated by reduction. Therefore, the cell for carbon dioxide electrolysis has a multilayer structure, and is more complicated than the cell for water electrolysis. As an electrochemical reaction device for performing carbon dioxide electrolysis, for example, a device is known in which a gas flow path for supplying carbon dioxide gas is provided on the side of a gas diffusion layer opposite to a catalyst layer, with respect to a cathode in which the catalyst layer is formed using a carbon dioxide reduction catalyst on the side of the gas diffusion layer in contact with an electrolyte solution (for example, patent document 1).

Documents of the prior art

Patent document

Patent document 1: international publication No. 2018/232515

Disclosure of Invention

Problems to be solved by the invention

The conventional electrochemical reaction device as in patent document 1 is still insufficient in energy efficiency, and it can be said that it is far from reaching a significant point to further reduce the loss and improve the energy efficiency.

The purpose of the present invention is to provide an electrochemical reaction device capable of electrochemically reducing carbon dioxide with high energy efficiency.

Means for solving the problems

The present invention adopts the following scheme.

(1) An electrochemical reaction device (for example, the electrochemical reaction device 10 according to an embodiment) according to an aspect of the present invention is an electrochemical reaction device for electrochemically reducing carbon dioxide, including: a cathode (e.g., cathode 21 of the embodiment); an anode (e.g., anode 22 of an embodiment); an ion exchange membrane (e.g., ion exchange membrane 26 of an embodiment) adjacent to a surface of the cathode side of the anode; a flow channel structure (for example, the flow channel structure 23 of the embodiment) that is provided between the cathode and the ion exchange membrane and forms an electrolyte flow channel (for example, the electrolyte flow channel 31 of the embodiment); a first gas flow path structure (for example, a first gas flow path structure 24 according to an embodiment) that is provided on the cathode opposite to the anode and that forms a cathode-side gas flow path (for example, a cathode-side gas flow path 32 according to an embodiment) for supplying carbon dioxide gas; a second gas flow channel structure (for example, the second gas flow channel structure 25 according to the embodiment) that is provided on the opposite side of the anode from the cathode and that forms an anode-side gas flow channel (for example, the anode-side gas flow channel 33 according to the embodiment); a first power supply member (for example, a first power supply member 27 according to the embodiment) provided on the side opposite to the cathode of the first gas flow path structure; and a second power supply member (for example, a second power supply member 28 according to the embodiment) provided on the side of the second gas flow passage structure opposite to the anode.

(2) A plurality of electrolyte flow paths, a plurality of cathode-side gas flow paths, and a plurality of anode-side gas flow paths may be formed, and at least between a pair of the electrolyte flow paths, the cathode, the anode, and the ion exchange membrane may be sandwiched by portions other than the flow paths of the liquid flow path structure, the first gas flow path structure, and the second gas flow path structure.

(3) The cathode-side gas flow field, the electrolyte flow field, and the anode-side gas flow field may be respectively provided in the same number, and may be arranged so as to overlap each other when viewed in the thickness direction, and the cathode, the anode, and the ion exchange membrane may be sandwiched between all adjacent electrolyte flow fields by portions other than the flow fields of the liquid flow field structure, the first gas flow field structure, and the second gas flow field structure.

Effects of the invention

According to the aspects (1) to (3), an electrochemical reaction device capable of electrochemically reducing carbon dioxide with high energy efficiency can be provided.

Drawings

Fig. 1 is a cross-sectional view of an electrochemical reaction device according to an embodiment, taken along a plane perpendicular to the longitudinal direction of an electrolyte flow channel.

Fig. 2 is a cross-sectional view of the electrochemical reaction device of fig. 1, taken along a plane in the longitudinal direction of the electrolyte flow channel.

Fig. 3 is a view of the liquid flow channel structure of the electrochemical reaction device of fig. 1 as viewed from the cathode side.

Fig. 4 is a view of the first gas flow channel structure of the electrochemical reaction device of fig. 1 as viewed from the cathode side.

Fig. 5 is a view of the second gas flow channel structure of the electrochemical reaction device of fig. 1 as viewed from the anode side.

Fig. 6 is a cross-sectional view of an electrochemical reaction device according to another embodiment, taken along a plane perpendicular to the longitudinal direction of the electrolyte solution flow path.

Description of the reference numerals

10. An electrochemical reaction device, 21.. cathode, 22.. anode, 23a.. flow path structure, 24.. first gas flow path structure, 25.. second gas flow path structure, 26.. ion exchange membrane, 27.. first power supply, 28.. second power supply, 31.. electrolyte flow path, 32.. cathode side gas flow path, 33.. anode side gas flow path.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The dimensions and the like of the drawings illustrated in the following description are examples, and the present invention is not limited to these, and can be implemented by being appropriately modified within a range not changing the gist thereof.

The electrochemical reaction apparatus 10 of the embodiment illustrated in fig. 1 to 5 is an apparatus for electrochemically reducing carbon dioxide. The electrochemical reaction device 10 includes a cathode 21, an anode 22, a liquid flow path structure 23, a first gas flow path structure 24, a second gas flow path structure 25, an ion exchange membrane 26, a first power supply 27, and a second power supply 28. In the electrochemical reaction device 10, the first power supply body 27, the first gas flow path structure 24, the cathode 21, the liquid flow path structure 23, the ion exchange membrane 26, the anode 22, the second gas flow path structure 25, and the second power supply body 28 are stacked in this order.

As shown in fig. 3, 6 linear slits 23a are formed in parallel with each other in the liquid flow path structure 23. The portion of each slit 23a surrounded by the cathode 21, the ion exchange membrane 26, and the flow channel structure 23 serves as an electrolyte flow channel 31. An inlet-side flow passage 31a for distributing the electrolyte supplied from the outside to each electrolyte flow passage 31 is formed on one side in the longitudinal direction of each electrolyte flow passage 31. On the other side in the longitudinal direction of each electrolyte solution flow path 31, an outlet side flow path 31b is formed to collect and discharge the electrolyte solution flowing through each electrolyte solution flow path 31.

The shape of the electrolyte solution flow path 31 as viewed in the thickness direction is not particularly limited, and is preferably linear since the pressure loss is small.

The height of the electrolyte flow path 31, that is, the distance between both ends of the electrolyte flow path 31 in the thickness direction of the flow path structure 23 may be set so that the ion transfer resistance from the cathode 21 to the anode 22 is small within a possible range, and may be set to 0.1 to 5mm, for example. The width of the electrolyte flow path 31 can be set as appropriate, and can be set to 0.1 to 1mm, for example.

The number of the electrolyte solution passages 31 provided in the electrochemical reaction device 10 is not limited to 6, and may be set as appropriate depending on the size of the electrochemical reaction device 10, for example, 5 to 1000.

As shown in fig. 4, 6 linear grooves 24a are formed in parallel with each other on the surface of the first gas flow path structure 24 on the cathode 21 side. The portion surrounded by the first gas flow structure 24 and the cathode 21 in each groove 24a serves as a cathode-side gas flow field 32. On one side in the longitudinal direction of each cathode-side gas flow path 32, an inlet-side flow path 32a is formed for distributing carbon dioxide gas supplied from the outside to each cathode-side gas flow path 32. On the other longitudinal side of each cathode-side gas flow path 32, an outlet-side flow path 32b is formed for collecting and discharging a gaseous product generated by the reduction reaction in the cathode 21 from each cathode-side gas flow path 32.

In the present embodiment, the inlet side flow path 31a of the electrolyte flow path 31 and the inlet side flow path 32a of the cathode gas flow path 32 are disposed on opposite sides in the longitudinal direction of the flow paths. That is, the flow direction of the electrolyte in the electrolyte flow path 31 and the flow direction of the carbon dioxide gas and the gaseous products in the cathode gas flow path 32 are opposite (counter-current) to each other. In the aspect of high reduction efficiency of carbon dioxide, it is preferable that the flow of the electrolyte and the flow of the carbon dioxide gas and the gaseous product are in counter-current as in this example. The electrochemical reaction apparatus according to the embodiment may be configured such that the flow direction of the electrolyte and the flow direction of the carbon dioxide gas and the gaseous product are the same direction (sub-flow).

The shape of the cathode-side gas flow field 32 as viewed in the thickness direction may be identical to the shape of the electrolyte flow field 31, but is preferably straight because of a small pressure loss. The size of the cathode-side gas flow field 32 can be set as appropriate. When the cathode-side gas flow path 32 and the electrolyte flow path 31 are completely overlapped with each other when viewed in the thickness direction, the surface pressure can be applied across the electrodes, and the cathode-side gas flow path 32 and the electrolyte flow path 31 are preferably the same in width since the electricity supplied from the power supply body can be uniformly performed in each portion without loss.

The number of cathode-side gas flow paths 32 included in the electrochemical reaction device 10 is not limited to 6, and may be set appropriately according to the size of the electrochemical reaction device 10, for example, 5 to 1000.

As shown in fig. 5, 6 straight grooves 25a are formed in parallel with each other on the surface of the second gas flow structure 25 on the anode 22 side. The portion surrounded by the second gas flow structure 25 and the anode 22 in each groove 25a serves as an anode-side gas flow field 33. An outlet side channel 33a is formed on one side of each of the anode side gas channels 33 in the longitudinal direction, and collects and discharges oxygen generated in the anode 22 from each of the anode side gas channels 33.

The shape of the anode gas flow field 33 is not particularly limited, and is preferably straight since the pressure loss is small. The size of the anode gas channel 33 can be set as appropriate. When the anode-side gas flow path 33 and the electrolyte flow path 31 are completely overlapped with each other when viewed in the thickness direction, the surface pressure can be applied across the electrodes, and the cathode-side gas flow path 32, the electrolyte flow path 31, and the anode-side gas flow path 33 are preferably the same in width, since the electricity supplied from the power supply body can be uniformly performed in each portion without loss.

The number of the anode-side gas channels 33 included in the electrochemical reaction device 10 is not limited to 6, and may be set appropriately according to the size of the electrochemical reaction device 10, for example, 5 to 1000. The number of the electrolyte solution flow paths 31, the cathode gas flow paths 32, and the anode gas flow paths 33 is preferably the same.

As described above, in the electrochemical reaction device 10, as shown in fig. 1 and 2, a plurality of electrolyte flow paths 31 are formed between the cathode 21 and the anode 22, a plurality of cathode-side gas flow paths 32 are formed on the side of the cathode 21 opposite to the anode 22, and a plurality of anode-side gas flow paths 33 are formed on the side of the anode 22 opposite to the cathode 21. In this example, the same number of electrolyte flow paths 31, cathode-side gas flow paths 32, and anode-side gas flow paths 33, 1 each extending in parallel at a position where they overlap each other, are provided, as viewed in the thickness direction (stacking direction).

The first power feeder 27 and the second power feeder 28 are electrically connected to a power supply device not shown. The first gas flow field structure 24 and the second gas flow field structure 25 are electrically conductive, and can apply a voltage between the cathode 21 and the anode 22 by electric power supplied from a power supply device.

The cathode 21 is an electrode for reducing carbon dioxide and reducing water. The cathode 21 may be any electrode that can electrochemically reduce carbon dioxide and allow a gaseous product generated by a reduction reaction to pass through the cathode-side gas flow passage 32, and may be, for example, an electrode in which a cathode catalyst layer is formed on the electrolyte flow passage 31 side of a gas diffusion layer. The cathode catalyst layer may also partially enter the gas diffusion layer. A porous layer that is denser than the gas diffusion layer may be disposed between the gas diffusion layer and the cathode catalyst layer.

As the cathode catalyst forming the cathode catalyst layer, a known catalyst that promotes the reduction of carbon dioxide can be used. Specific examples of the cathode catalyst include metals such as gold, silver, copper, platinum, palladium, nickel, cobalt, iron, manganese, titanium, cadmium, zinc, indium, gallium, lead, and tin, and metal complexes such as alloys, intermetallic compounds, ruthenium complexes, and rhenium complexes thereof. Among these, copper and silver are preferable, and copper is more preferable, from the viewpoint of promoting the reduction of carbon dioxide. One kind of the cathode catalyst may be used alone, or two or more kinds may be used in combination.

As the cathode catalyst, a supported catalyst in which metal particles are supported on a carbon material (carbon particles, carbon nanotubes, graphene, or the like) may be used.

The gas diffusion layer of the cathode 21 is not particularly limited, and for example, carbon paper or carbon cloth can be used.

The method for producing the cathode 21 is not particularly limited, and for example, a method of coating a liquid composition containing a cathode catalyst on the surface of the gas diffusion layer on the side to be the electrolyte solution flow path 31 and drying the composition can be exemplified.

The anode 22 is an electrode for oxidizing hydroxide ions to generate oxygen. The anode 22 may be any electrode that can electrochemically oxidize hydroxide ions and allow generated oxygen to permeate through the anode-side gas flow passage 33, and for example, an electrode in which an anode catalyst layer is formed on the side of the gas diffusion layer facing the electrolyte solution flow passage 31 may be used.

The anode catalyst forming the anode catalyst layer is not particularly limited, and a known anode catalyst can be used. Specifically, examples of the metal include metals such as platinum, palladium, and nickel, alloys thereof, intermetallic compounds, metal oxides such as manganese oxide, iridium oxide, nickel oxide, cobalt oxide, iron oxide, tin oxide, indium oxide, ruthenium oxide, lithium oxide, and lanthanum oxide, and metal complexes such as ruthenium complexes and rhenium complexes. One kind of the anode catalyst may be used alone, or two or more kinds may be used in combination.

Examples of the gas diffusion layer of the anode 22 include carbon paper and carbon cloth. As the gas diffusion layer, a porous material such as a mesh material, a punched material, a porous body, or a metal fiber sintered body may be used. Examples of the material of the porous body include metals such as titanium, nickel, and iron, and alloys thereof (e.g., SUS).

The ion exchange membrane 26 may be a membrane that allows hydroxide ions to pass therethrough and does not allow oxygen generated at the anode 22 to pass therethrough, and a known anion exchange membrane may be used.

As the anion exchange membrane, for example, an anion exchange membrane containing a hydrocarbon-based anion exchange resin can be exemplified. Examples of the hydrocarbon-based anion exchange resin include anion exchange resins obtained by introducing various functional groups as required, such as polysulfone, polyether ketone, and polyether ether ketone.

The thickness of the ion exchange membrane 26 is preferably 0.03 to 0.5mm, and more preferably 0.05 to 0.1 mm. If the thickness of the ion-exchange membrane 26 is not less than the lower limit of the above range, mechanical strength and durability can be obtained. If the thickness of the ion exchange membrane 26 is equal to or less than the upper limit of the above range, the ion transfer resistance is suppressed to be low.

As a material of the fluid flow path structure 23, for example, a fluororesin such as polytetrafluoroethylene can be exemplified.

Examples of the material of the first gas flow path structure 24 and the second gas flow path structure 25 include metal such as titanium and SUS, and carbon.

Examples of the material of the first power feeder 27 and the second power feeder 28 include metal such as copper, gold, titanium, and SUS, and carbon. As the first power feeder 27 and the second power feeder 28, power feeders obtained by plating a surface of a copper base with gold plating or the like may be used.

When carbon dioxide is electrochemically reduced using the electrochemical reaction apparatus 10, carbon dioxide in the atmosphere or exhaust gas is concentrated by a known concentration apparatus such as a membrane separation apparatus, and the concentrated gas is absorbed and recovered in an absorption liquid such as ethanolamine. Then, the absorbing liquid having absorbed the carbon dioxide is heated to release the carbon dioxide gas, and the carbon dioxide gas is supplied to the cathode-side gas flow path 32 of the electrochemical reaction device 10. Further, the electrolyte is caused to flow into the electrolyte flow path 31, and a voltage is applied between the cathode 21 and the anode 22. Thus, carbon dioxide is electrochemically reduced at the cathode 21 by carbon dioxide electrolysis accompanied by water electrolysis to obtain a gaseous product containing ethylene and the like.

The electrolyte solution is not particularly limited, and examples thereof include an aqueous potassium hydroxide solution and an aqueous sodium hydroxide solution. Among them, an aqueous potassium hydroxide solution is preferable from the viewpoint of promoting the reduction of carbon dioxide.

In the cathode 21, carbon dioxide is reduced to produce carbon monoxide and ethylene in the following reaction, for example. Hydrogen is also generated in the cathode 21 in the following reaction. The produced gaseous products such as carbon monoxide, ethylene, and hydrogen permeate the gas diffusion layer of the cathode 21 and flow out of the cathode-side gas flow passage 32.

CO ₂ +H ₂ O→CO+2OH ^-

2CO+8H ₂ O→C ₂ H ₄ +8OH ^- +2H ₂ O

2H ₂ O→H ₂ +2OH ^-

The hydroxide ions generated at the cathode 21 are transferred to the anode 22 through the electrolyte and the ion-exchange membrane 26, and oxidized in the following reaction to generate oxygen. The generated oxygen permeates the gas diffusion layer of the anode 22 and is discharged from the anode-side gas flow path 33.

4OH ^- →O ₂ +2H ₂ O

In the electrochemical reaction device 10, the ion exchange membrane 26 is adjacently disposed on the surface of the anode 22 on the cathode 21 side. In the ion exchange membrane 26, the hydroxide ions move toward the anode 22, and the permeation of oxygen is hindered. This can suppress the migration of oxygen generated at the anode 22 toward the cathode 21. Therefore, the loss due to the side reaction of oxygen at the cathode 21 can be reduced. Further, by providing the ion exchange membrane 26 on the anode 22 side of the electrolyte passage 31, the resistance to ion transfer to the anode 22 is reduced. Thus, the loss in carbon dioxide electrolysis accompanying water electrolysis is reduced, and the energy efficiency is improved.

In the cathode 21, the liquid flow path 31 and the cathode-side gas flow path 32 are not sandwiched between the liquid flow path structure 23 and the second gas flow path structure 25. Therefore, if the electrolyte solution flow path 31, the cathode-side gas flow path 32, and the anode-side gas flow path 33 are each 1-bar flow path having a wide width, the cathode 21 and the anode 22 are supported only at both ends in the width direction, and therefore it is difficult to apply a sufficient surface pressure to the cathode 21 and the anode 22 when the laminated members of the electrochemical reaction device 10 are fastened by bolts, nuts, or the like. As a result, the current density in the width direction of the flow path in the width direction of the cathode 21 and the anode 22 is likely to be uneven, which results in energy loss.

In contrast, as shown in fig. 1, in this example, the electrolyte solution flow paths 31, the cathode-side gas flow paths 32, and the anode-side gas flow paths 33 are equal in number, and each flow path has a straight line shape and a uniform width. The electrolyte solution flow path 31, the cathode-side gas flow path 32, and the anode-side gas flow path 33 are arranged so as to overlap each other when viewed in the thickness direction (stacking direction). The cathode 21 is sandwiched between the electrolyte flow channels 31 adjacent to each other and the portion of the liquid flow channel structure 23 other than the electrolyte flow channels 31 and the portion of the first gas flow channel structure 24 other than the cathode-side gas flow channels 32. In addition, the anode 22 and the ion exchange membrane 26 are sandwiched between the portions of the flow channel structures 23 other than the electrolyte flow channels 31 and the portions of the second gas flow channel structures 25 other than the anode-side gas flow channels 33, between all the adjacent electrolyte flow channels 31.

In the electrochemical reaction device 10, by adopting such a configuration, when the respective laminated members are fastened and fixed in the thickness direction (lamination direction) by bolts, nuts, or the like, surface pressure is reliably applied to the cathode 21, the anode 22, and the ion exchange membrane 26 at multiple points between the adjacent flow paths. Thus, the first power supply body 27, the first gas flow path structure 24, and the cathode 21 are reliably in close contact with each other, and therefore, the loss of the supply of electricity from the first power supply body 27 to the cathode 21 can be reduced. Similarly, since the second power supply body 28, the second gas flow passage structure 25, and the anode 22 are reliably in close contact with each other, the loss of the electric power supplied from the second power supply body 28 to the anode 22 can be reduced. In this case, the current density in the width direction of each electrolyte flow path 31 becomes uniform in the cathode 21 and the anode 22, and the energy efficiency further increases.

As described above, in the electrochemical reaction device 10 of the embodiment, the ion exchange membrane 26 is provided adjacent to the cathode 21 side of the anode 22, and the electrolyte solution flow path 31 is formed between the cathode 21 and the ion exchange membrane 26. This prevents the oxygen generated at the anode 22 from moving toward the cathode 21 by the ion exchange membrane 26, and reduces the loss due to the side reaction of oxygen at the cathode 21, thereby achieving high energy efficiency.

The electrochemical reaction apparatus of the present invention is not limited to the electrochemical reaction apparatus 10. For example, when a plurality of electrolyte flow paths, cathode-side gas flow paths, and anode-side gas flow paths are formed, and the cathode, the anode, and the ion exchange membrane are sandwiched between at least one set of electrolyte flow paths by the flow path structure and the second gas flow path structure other than the flow paths, the number of the electrolyte flow paths, the cathode-side gas flow paths, and the anode-side gas flow paths may be different.

Specifically, the electrochemical reaction apparatus 20 illustrated in fig. 6 may be used. In fig. 6, the same portions as those in fig. 1 are denoted by the same reference numerals and description thereof is omitted. The electrochemical reaction device 20 is similar to the electrochemical reaction device 20 except that the liquid flow path structure 23A is provided instead of the liquid flow path structure 23.

In the liquid flow path structure 23A, 3 wide slits 23A are formed in parallel with each other, which overlap with both of 2 cathode-side gas flow paths 32 adjacent to each other with a space therebetween when viewed from the thickness direction. The portion surrounded by the cathode 21, the ion exchange membrane 26, and the flow channel structure 23A in each slit 23A is 3 electrolyte flow channels 31A.

In the electrochemical reaction device 20, the electrolyte solution flow paths 31A and the cathode gas flow paths 32 correspond to each other in 1 to 2, and 2 cathode gas flow paths 32 are disposed so as to overlap 1 electrolyte solution flow path 31 when viewed in the thickness direction. Similarly, the electrolyte solution flow paths 31A and the anode gas flow paths 33 correspond to each other in 1 to 2, and 2 anode gas flow paths 33 are arranged so as to overlap 1 electrolyte solution flow path 31 when viewed in the thickness direction.

In the electrochemical reaction device 20, the cathode 21 is sandwiched between the electrolyte flow channels 31A adjacent to each other and the portions of the liquid flow channel structure 23A other than the electrolyte flow channels 31A and the portions of the first gas flow channel structure 24 other than the cathode-side gas flow channels 32. Similarly, between the adjacent electrolyte solution flow channels 31A, the anode 22 and the ion exchange membrane 26 are sandwiched between the portion of the flow channel structure 23A other than the electrolyte solution flow channel 31A and the portion of the second gas flow channel structure 25 other than the anode-side gas flow channel 33.

Therefore, in the electrochemical reaction device 20, when the respective laminated members are fastened and fixed in the thickness direction (lamination direction) by bolts, nuts, or the like, surface pressure is reliably applied to the cathode 21, the anode 22, and the ion exchange membrane 26 at a plurality of points between the adjacent electrolyte solution flow paths 31A. Therefore, the loss in the supply of electricity from the first power feeder 27 to the cathode 21 and the loss in the supply of electricity from the second power feeder 28 to the anode 22 can be reduced, and the energy efficiency can be further improved.

The electrochemical reaction device 10 is preferable to the electrochemical reaction device 20 in that the cathode 21 and the anode 22 can be supported at a larger number of points, a surface pressure can be easily applied to the cathode 21 and the anode 22, and a current density can be easily made uniform.

Further, if the cathode-side ion exchange membrane of the anode is provided adjacent to each other, 1 electrochemical reaction device may be provided for each of the electrolyte solution flow path, the cathode-side gas flow path, and the anode-side gas flow path.

In addition, the components in the above embodiments may be replaced with known components as appropriate without departing from the scope of the present invention, and the above modifications may be combined as appropriate.

Claims

1. An electrochemical reaction device for electrochemically reducing carbon dioxide, wherein,

the electrochemical reaction device is provided with:

a cathode;

an anode;

an ion exchange membrane adjacent to a surface of the cathode side of the anode;

a liquid flow path structure provided between the cathode and the ion exchange membrane, and forming an electrolyte flow path;

a first gas flow path structure provided on the cathode opposite to the anode, and having a cathode-side gas flow path for supplying carbon dioxide gas;

a second gas flow path structure provided on the opposite side of the anode from the cathode, and forming an anode-side gas flow path;

a first power supply body provided on the side of the first gas flow path structure opposite to the cathode; and

and a second power supply body provided on the second gas flow path structure on the side opposite to the anode.

2. The electrochemical reaction device according to claim 1,

a plurality of electrolyte flow paths, a plurality of cathode-side gas flow paths, and a plurality of anode-side gas flow paths are formed,

the cathode, the anode, and the ion exchange membrane are sandwiched between at least one of the electrolyte solution flow channels by the liquid flow channel structure, the first gas flow channel structure, and the second gas flow channel structure except for the flow channels.

3. The electrochemical reaction apparatus according to claim 2,

the cathode-side gas flow channels, the electrolyte flow channels, and the anode-side gas flow channels are respectively the same number, and are arranged so as to overlap when viewed in the thickness direction, and the cathode, the anode, and the ion exchange membrane are sandwiched between all adjacent electrolyte flow channels by portions other than the flow channels of the liquid flow channel structure, the first gas flow channel structure, and the second gas flow channel structure.