Method for producing ethylene, carbon dioxide reduction electrode, and carbon dioxide reduction device

Abstract

The present invention addresses the problem of providing a method for producing ethylene having high ethylene selectivity, a carbon dioxide reduction electrode, and a carbon dioxide reduction device. The present invention relates to a method for producing ethylene, a carbon dioxide reduction electrode, and a carbon dioxide reduction device, the method comprising a step for reacting carbon dioxide with water in the presence of a carbon dioxide reduction catalyst, the carbon dioxide reduction catalyst is a polynuclear copper complex, and the distance between copper atoms as determined by the density functional method is # imgabs0 # or less.

Description

Technical Field

[0001] The present disclosure relates to a method for producing ethylene, a carbon dioxide reduction electrode, and a carbon dioxide reduction device. Background Art

[0002] In the process of producing ethylene by reducing carbon dioxide, a carbon dioxide reduction catalyst that is a copper complex is sometimes used.

[0003] For example, Patent Document 1 proposes a “carbon compound reduction catalyst characterized by comprising a metal complex comprising: a ligand having a phosphorus atom; and a metal halide salt having two metal atoms, at least one of which is Cu.”

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-109157 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] In ethylene production methods using a copper-catalyzed carbon dioxide reduction catalyst, many by-products are likely to be produced, and ethylene selectivity tends to be low. Therefore, there is a demand for the development of ethylene production methods with high ethylene selectivity.

[0009] An object of one embodiment of the present disclosure is to provide a method for producing ethylene with high ethylene selectivity.

[0010] Another embodiment of the present disclosure aims to provide a carbon dioxide reduction electrode having high ethylene selectivity.

[0011] Another embodiment of the present disclosure aims to provide a carbon dioxide reduction device with high ethylene selectivity.

[0012] Means for solving problems

[0013] Means for solving the above-mentioned problems include the following means.

[0014] <1> A method for producing ethylene, comprising reacting carbon dioxide with water in the presence of a carbon dioxide reduction catalyst, wherein the carbon dioxide reduction catalyst is a polynuclear copper complex and the distance between copper atoms obtained by density functional theory is the following.

[0015] <2> like <1> In the method for producing ethylene, the carbon dioxide reduction catalyst is a multinuclear copper complex in which a copper atom is coordinately bonded to two oxygen atoms.

[0016] <3> A method for producing ethylene comprises the step of reacting carbon dioxide with water in the presence of a carbon dioxide reduction catalyst represented by the following formula (1).

[0017] [Chemical Formula 1]

[0018]

[0019] In the above formula (1),

[0020] R 1 Represents a hydrogen atom or a substituent, and there are multiple R 1 Each can be the same or different. 1 They can bond to each other to form a ring. 1 represents a divalent group containing one or more aromatic rings. 1 and Q 2 represents a monovalent group containing one or more aromatic rings, Q 1 With Q 2 They can bond to each other to form a ring structure. a is an integer from 2 to 4. X is a counterion or a neutral molecule, and b is an integer from 0 to 1. In the case of multiple Xs, each of them can be the same or different. O is an oxygen atom bonded to at least one copper atom.

[0021] <4> like <3> The method for producing ethylene, wherein the aforementioned P 1 The following formula (P a ) or the following formula (P b ) represented by a divalent group.

[0022] [Chemical Formula 2]

[0023]

[0024] The above formula (P a ), R 2 and R 3 Each independently represents a hydrogen atom or a substituent, and two adjacent R 2 Each other and the two adjacent R 3 They can be bonded to each other to form a ring structure. b ), R 4 and R 5 represents a hydrogen atom or a substituent, two adjacent R 4 Each other, and adjacent R 4 With R 5 Can bond with each other to form a ring structure. 4 They may be the same or different. Note that * represents a connecting bond.

[0025] <5> like <3> In the method for producing ethylene, the carbon dioxide reduction catalyst is a compound represented by the following formula (2).

[0026] [Chemical Formula 3]

[0027]

[0028] In the above formula (2), R 6 ~R 8 Each independently represents a hydrogen atom or a substituent, and two adjacent R 6 Two adjacent Rs 7 Each other, and the two adjacent R 8 They can bond with each other to form a ring structure. 6 ~R 8 Each can be the same or different. 3 and Q 4 represents a monovalent group containing one or more aromatic rings, Q 3 With Q 4 They can bond to each other to form a ring structure. a is an integer from 2 to 4. X is a counterion or a neutral molecule, and b is an integer from 0 to 1. In the case of multiple Xs, each of them can be the same or different. O is an oxygen atom bonded to at least one copper atom.

[0029] <6> like <3> In the method for producing ethylene, the carbon dioxide reduction catalyst is a compound represented by the following formula (3).

[0030] [Chemical Formula 4]

[0031]

[0032] In the above formula (3), R 9 ~R 13 Each independently represents a hydrogen atom, a substituent or a divalent group, and two adjacent R 9 Two adjacent Rs 10 Two adjacent Rs 11 Two adjacent Rs 12 Each other, and adjacent R 12 With R 13 Can bond with each other to form a ring structure. 9 ~R 12 Each may be the same or different. 13 When it is a divalent group, the divalent group can form a bond with another compound represented by the above formula (3) to form a dimer. X is a counterion or a neutral molecule, b is an integer greater than 0, and when there are multiple Xs, each of them may be the same or different.

[0033] <7> like <3> In the method for producing ethylene, the carbon dioxide reduction catalyst is a compound represented by the following formula (4).

[0034] [Chemical Formula 5]

[0035]

[0036] In the above formula (4), R 14 ~R 16 Each independently represents a hydrogen atom or a substituent, and two adjacent R 14 Two adjacent Rs 15 Each other, and adjacent R 15 With R 16 Can be connected to form a ring. There are multiple R 14 ~R 16 Each of them may be the same or different. X is a counter ion or a neutral molecule, b is an integer greater than or equal to 0, and when there are a plurality of Xs, each of them may be the same or different.

[0037] <8> like <3> In the method for producing ethylene, the carbon dioxide reduction catalyst is a compound represented by the following formula (5).

[0038] [Chemical Formula 6]

[0039]

[0040] In the above formula (5), R 17 ~R 21 Each independently represents a hydrogen atom or a substituent, and two adjacent R 17 Two adjacent Rs 18 Two adjacent Rs 19 Two adjacent Rs 20 Each other, and the two adjacent R 21 They can be connected to each other to form a ring. 17 ~R 21 Each of them may be the same or different. X is a counter ion or a neutral molecule, b is an integer greater than or equal to 0, and when there are a plurality of Xs, each of them may be the same or different.

[0041] <9> like <3> In the method for producing ethylene, the carbon dioxide reduction catalyst is a compound represented by the following formula (6).

[0042] [Chemical Formula 7]

[0043]

[0044] In formula (6), R 22 ~R 26 Each independently represents a hydrogen atom or a substituent, and two adjacent R 22 Two adjacent Rs 23 Two adjacent Rs 24 Two adjacent Rs 26 Each other, and adjacent R 25 With R 26 Can bond with each other to form a ring structure. 22 ~R 26 Each of them may be the same or different. X is a counter ion or a neutral molecule, b is an integer greater than or equal to 0, and when there are a plurality of Xs, each of them may be the same or different.

[0045] <10> like <3> In the method for producing ethylene, the carbon dioxide reduction catalyst is a compound represented by the following formula (7).

[0046] [Chemical Formula 8]

[0047]

[0048] In the above formula (7), R 27 ~R 34 Each independently represents a hydrogen atom or a substituent, and two adjacent R 27 Two adjacent Rs 28 Two adjacent Rs 29 Two adjacent Rs 30 Two adjacent Rs 31 Two adjacent Rs 32 Two adjacent Rs 33 Each other, and the two adjacent R 34 They can bond with each other to form a ring structure. 27 ~R 34 Each of these may be the same or different. Ar represents a divalent aromatic group which may have a substituent. a is an integer from 2 to 4. X is a counterion or a neutral molecule, and b is an integer from 0 to 1. In the case of a plurality of Xs, each may be the same or different. O is an oxygen atom bonded to at least one copper atom.

[0049] <11> The carbon dioxide reduction electrode comprises a multinuclear copper complex and the distance between copper atoms calculated by density functional theory is The following carbon dioxide reduction catalyst, or a conductive material of a carbon dioxide reduction catalyst represented by the following formula (1).

[0050] [Chemical Formula 9]

[0051]

[0052] In the above formula (1),

[0053] R 1 Represents a hydrogen atom or a substituent, and there are multiple R 1 Each can be the same or different. 1 They can bond to each other to form a ring. 1 represents a divalent group containing one or more aromatic rings. 1 and Q 2 represents a monovalent group containing one or more aromatic rings, Q 1 With Q 2 They can bond to each other to form a ring structure. a is an integer from 2 to 4. X is a counterion or a neutral molecule, and b is an integer from 0 to 1. In the case of multiple Xs, each of them can be the same or different. O is an oxygen atom bonded to at least one copper atom.

[0054] <12> like <11> The carbon dioxide reduction electrode further comprises a support for supporting the conductive material.

[0055] <13> like <11> or <12> The carbon dioxide reduction electrode comprises an ion conductor.

[0056] <14> A carbon dioxide reduction device comprising: an oxidation electrode; <11> ~ <13> The carbon dioxide reduction electrode according to any one of the preceding claims; a membrane separating the oxidation electrode from the carbon dioxide reduction electrode; an electrolyte; and a power source connected to the oxidation electrode and the carbon dioxide reduction electrode.

[0057] Effects of the Invention

[0058] According to one embodiment of the present disclosure, a method for producing ethylene with high ethylene selectivity is provided.

[0059] According to another embodiment of the present disclosure, a carbon dioxide reduction electrode having high ethylene selectivity is provided.

[0060] According to another embodiment of the present disclosure, a carbon dioxide reduction apparatus with high ethylene selectivity is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] [ Figure 1 ] is a schematic cross-sectional view showing an example of a carbon dioxide reduction electrode involved in the present disclosure.

[0062] [ Figure 2 ] is a schematic cross-sectional view showing an example of a carbon dioxide reduction device involved in the present disclosure. DETAILED DESCRIPTION

[0063] Hereinafter, an embodiment of the present disclosure will be described. These descriptions and examples illustrate the embodiment and do not limit the scope of the invention.

[0064] In this specification, the numerical range expressed using "to" means a range including the numerical values ​​described before and after "to" as the lower limit and the upper limit.

[0065] In the numerical ranges recorded in stages in this specification, the upper limit or lower limit recorded in one numerical range may also be replaced by the upper limit or lower limit of the numerical range recorded in other stages. In addition, in the numerical ranges recorded in this specification, the upper limit or lower limit of the numerical range may also be replaced by the value shown in the Examples.

[0066] In this specification, a combination of preferred embodiments is a more preferred embodiment.

[0067] Each component may contain a plurality of corresponding substances.

[0068] When referring to the amount of each component in a composition, if there are multiple substances belonging to each component in the composition, unless otherwise specified, it refers to the total amount of the multiple substances present in the composition.

[0069] The term "process" includes not only independent processes but also processes that cannot be clearly distinguished from other processes as long as the intended effect of the process can be achieved.

[0070] Examples of "substituents" include halogen atoms, alkyl groups (including cycloalkyl groups), alkenyl groups, alkynyl groups, alkoxy groups, alkylthio groups, aryl groups, aryloxy groups, arylthio groups, monovalent heterocyclic groups, substituted amino groups, acyl groups, imide residues, amide groups, imido groups, substituted oxycarbonyl groups, cyano groups, alkylsulfonyl groups, and nitro groups. It should be noted that when the number of carbon atoms is mentioned in this specification, this number of carbon atoms generally does not include the number of carbon atoms in the substituent A.

[0071] The "aromatic hydrocarbon ring group" refers to an atomic group remaining after removing one or more hydrogen atoms directly bonded to carbon atoms constituting an aromatic hydrocarbon ring (which may be unsubstituted or substituted, and may have two or more rings condensed).

[0072] The "aromatic heterocyclic group" refers to an atomic group remaining after removing one or more hydrogen atoms directly bonded to carbon atoms or heteroatoms constituting an aromatic heterocyclic ring (which may be unsubstituted or substituted, and may have two or more rings condensed).

[0073] In the compound names, "t-" refers to tertiary, "n-" refers to normal, and "p-" refers to para.

[0074] <Method for producing ethylene>

[0075] One embodiment of the present disclosure relates to a method for producing ethylene, comprising the step of reacting carbon dioxide with water in the presence of a carbon dioxide reduction catalyst, wherein the carbon dioxide reduction catalyst is a polynuclear copper complex and the interatomic distance of copper obtained by density functional theory is the following.

[0076] The ethylene production method according to one embodiment of the present disclosure has the above-described configuration, and the reason for this is presumably as follows.

[0077] The production of ethylene using a carbon dioxide reduction catalyst that is a multinuclear copper complex is presumed to occur through the following process: carbon dioxide is coordinated to the copper atoms of the carbon dioxide reduction catalyst, and two carbon dioxide atoms coordinated to different copper atoms form bonds with each other, reacting with water to produce ethylene. The fact that two carbon dioxide atoms coordinated to different copper atoms easily form bonds with each other is believed to be effective in improving ethylene selectivity, and therefore, shortening the distance between copper atoms is presumed to be effective.

[0078] Here, in the method for producing ethylene according to one embodiment of the present disclosure, a carbon dioxide reduction catalyst is used, which is a multinuclear copper complex and the distance between copper atoms obtained by density functional theory is By setting this inter-copper atomic distance, two carbon dioxide atoms coordinated to different copper atoms can easily form a bond with each other. This is presumably a method for producing ethylene with high ethylene selectivity.

[0079] A method for producing ethylene according to another embodiment of the present disclosure includes a step of reacting carbon dioxide with water in the presence of a carbon dioxide reduction catalyst represented by the following formula (1).

[0080] The method for producing ethylene according to another embodiment of the present disclosure has the above-mentioned configuration, and is thus a method for producing ethylene with high ethylene selectivity. The reason for this is presumably as follows.

[0081] Another embodiment of the present disclosure relates to a method for producing ethylene using a carbon dioxide reduction catalyst represented by the following formula (1). The carbon dioxide reduction catalyst has an inter-copper atomic distance sufficient to facilitate bonding between two carbon dioxide atoms coordinated to different copper atoms. This is presumably a method for producing ethylene with high ethylene selectivity.

[0082] [Chemical Formula 10]

[0083]

[0084] In the above formula (1), R 1Represents a hydrogen atom or a substituent, and there are multiple R 1 Each can be the same or different. 1 They can bond to each other to form a ring. 1 represents a divalent group containing one or more aromatic rings. 1 and Q 2 represents a monovalent group containing one or more aromatic rings, Q 1 With Q 2 They can bond to each other to form a ring structure. a is an integer from 2 to 4. X is a counterion or a neutral molecule, and b is an integer from 0 to 1. In the case of multiple Xs, each of them can be the same or different. O is an oxygen atom bonded to at least one copper atom.

[0085] The following describes in detail a method for producing ethylene according to one embodiment of the present disclosure and a method for producing ethylene according to another embodiment of the present disclosure. Hereinafter, the method for producing ethylene according to one embodiment of the present disclosure and the method for producing ethylene according to another embodiment of the present disclosure are collectively referred to as the "method for producing ethylene according to the present disclosure."

[0086] (Carbon Dioxide Reduction Catalyst)

[0087] The carbon dioxide reduction catalyst used in the method for producing ethylene according to the present disclosure will be described.

[0088] The carbon dioxide reduction catalyst is a multinuclear copper complex.

[0089] In one embodiment, the distance between copper atoms of the carbon dioxide reduction catalyst obtained by density functional theory is The following are preferably above The following are more preferably above The following is more preferably above the following.

[0090] Here, the distance between copper atoms is preferably The above reason is believed to be due to the fact that it is difficult to make the distance between copper atoms the following.

[0091] ·Calculation method of distance between copper atoms

[0092] The distance between copper atoms is calculated using a quantum chemical calculation program. As a quantum chemical calculation program, for example, Gaussian 16 manufactured by Gaussian Corporation can be used.

[0093] Density functional theory (B3LYP / def2svp, SDD for Cu) was used to perform structural optimization calculations on a carbon dioxide reduction catalyst, the target of which was the copper interatomic distances. If the SCF (self-consistent field) solution from the structural optimization calculations was unstable, further structural optimization calculations were performed to derive a stable solution.

[0094] From the viewpoint of ethylene selectivity, the carbon dioxide reduction catalyst is preferably a polynuclear copper complex in which at least one oxygen atom is coordinately bonded to one copper atom, and more preferably a polynuclear copper complex in which a copper atom is coordinately bonded to two oxygen atoms.

[0095] The carbon dioxide reduction catalyst is a compound represented by the following formula (1).

[0096] [Chemical Formula 11]

[0097]

[0098] In the above formula (1), R 1 Represents a hydrogen atom or a substituent, and there are multiple R 1 Each can be the same or different. 1 They can bond to each other to form a ring. 1 represents a divalent group containing one or more aromatic rings. 1 and Q 2 represents a monovalent group containing one or more aromatic rings, Q 1 With Q 2 They can bond to each other to form a ring structure. a is an integer from 2 to 4. X is a counterion or a neutral molecule, and b is an integer from 0 to 1. In the case of multiple Xs, each of them can be the same or different. O is an oxygen atom bonded to at least one copper atom.

[0099] In the above formula (1), R 1 , preferably a hydrogen atom, an alkyl group or an alkoxy group. 1 In the case of an alkyl group, an alkyl group having 1 to 10 carbon atoms is more preferred, and an n-butyl group is even more preferred. 1 In the case of an alkoxy group, an alkoxy group having 1 to 10 carbon atoms is more preferred, and a methoxy group is even more preferred.

[0100] In the above formula (1), Q 1 and Q 2 The aromatic ring contained in the monovalent group represented by includes an aromatic hydrocarbon ring group and an aromatic heterocyclic group. 1 and Q 2The aromatic heterocyclic group of the aromatic ring contained in the monovalent group represented by is preferably an aromatic heterocyclic group containing a nitrogen atom or an aromatic heterocyclic group containing a sulfur atom. 1 With Q 2 When they are bonded to each other to form a ring structure, the ring structure is preferably an atomic group remaining after removing two hydrogen atoms from phenanthroline, for example.

[0101] a is an integer of 2 or more and 4 or less, more preferably 2 or 4, and even more preferably 2.

[0102] The counter ion represented by X is preferably an anion, more preferably at least one anion selected from the group consisting of fluoride ion, chloride ion, bromide ion, iodide ion, sulfide ion, oxide ion, hydroxide ion, hydride ion, sulfite ion, phosphate ion, cyanide ion, acetate ion, 2-ethylhexanoate ion, carbonate ion, sulfate ion, nitrate ion, bicarbonate ion, trifluoroacetate ion, thiocyanide ion, trifluoromethanesulfonate ion, acetylacetonate, tetrafluoroborate ion, hexafluorophosphate ion, and tetraphenylborate ion. The neutral molecule represented by X is preferably at least one neutral molecule selected from the group consisting of water, methanol, ethanol, n-propanol, isopropanol, 2-methoxyethanol, 1,1-dimethylethanol, ethylene glycol, N,N'-dimethylformamide, N,N'-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, acetone, chloroform, acetonitrile, benzonitrile, triethylamine, pyridine, pyrazine, diazabicyclo[2,2,2]octane, 4,4'-bipyridine, tetrahydrofuran, diethyl ether, dimethoxyethane, methyl ethyl ether, 1,4-dioxane, acetic acid, propionic acid, and 2-ethylhexanoic acid.

[0103] b is an integer greater than or equal to 0, and is preferably, for example, greater than or equal to 0 and less than or equal to 4.

[0104] From the viewpoint of ethylene selectivity, in the above formula (1), P 1 Preferably, the following formula (P a ) or the following formula (P b ) represented by a divalent group.

[0105] [Chemical Formula 12]

[0106]

[0107] The above formula (P a ), R 2 and R 3 Each independently represents a hydrogen atom or a substituent, and two adjacent R 2 Each other and the two adjacent R 3 They can be bonded to each other to form a ring structure.b ), R 4 and R 5 represents a hydrogen atom or a substituent, two adjacent R 4 Each other, and adjacent R 4 With R 5 Can bond with each other to form a ring structure. 4 They may be the same or different. Note that * represents a connecting bond.

[0108] The above formula (P a ), R 2 It is preferably a hydrocarbon group, more preferably an alkyl group or alkenyl group having 1 to 6 carbon atoms, and further preferably an alkenyl group having 1 to 4 carbon atoms. 2 They are bonded to each other to form a ring structure, as two adjacent R 2 The ring structure formed by mutually bonding is preferably a benzene ring.

[0109] The above formula (P a ), R 3 Preferred is a hydrogen atom.

[0110] The above formula (P b ), R 4 Preferred is a hydrogen atom.

[0111] The above formula (P b ), R 5It is preferably an aromatic hydrocarbon ring group, preferably an unsubstituted or substituted aromatic hydrocarbon group having 30 or less carbon atoms, more preferably an unsubstituted or substituted phenyl group, an unsubstituted or substituted naphthyl group, an unsubstituted or substituted anthracenyl group, or an unsubstituted or substituted pyrenyl group, and further preferably an unsubstituted or substituted phenyl group. Specific examples of the substituent include halogen atoms such as fluorine, chlorine, bromine, and iodine atoms; hydroxyl groups, carboxyl groups, ester groups, mercapto groups, sulfonic acid groups, nitro groups, phosphonic acid groups; silyl groups having an alkyl group having 1 to 4 carbon atoms; methyl groups, ethyl groups, propyl groups, isopropyl groups, cyclopropyl groups, butyl groups, isobutyl groups, tert-butyl groups, pentyl groups, cyclopentyl groups, hexyl groups, cyclohexyl groups, norbornyl groups, nonyl groups, cyclononyl groups, decyl groups, 3,7-dimethyloctyl groups, adamantyl groups, dodecyl groups, cyclododecyl groups, pentadecyl groups, octadecyl groups, and docosyl groups; alkenyl groups, alkynyl groups; and linear, branched, or cyclic alkoxy groups having a total of about 1 to 50 carbon atoms, such as methoxy groups, ethoxy groups, propoxy groups, butoxy groups, pentyloxy groups, cyclohexyl groups, norbornyloxy groups, decyl groups, and dodecyloxy groups. The number of substituents may be any number as long as the substituent is possible, and is 1 to 5 for a phenyl group, 1 to 7 for a naphthyl group, and 1 to 9 for each of anthracenyl and pyrenyl groups.

[0112] From the viewpoint of ethylene selectivity, the carbon dioxide reduction catalyst is preferably a compound represented by the following formula (2).

[0113] [Chemical Formula 13]

[0114]

[0115] In the above formula (2), R 6 ~R 8 Each independently represents a hydrogen atom or a substituent, and two adjacent R 6 Two adjacent Rs 7 Each other, and the two adjacent R 8 They can bond with each other to form a ring structure. 6 ~R 8 Each can be the same or different. 3 and Q 4 represents a monovalent group containing one or more aromatic rings, Q 3 With Q 4 They can bond to each other to form a ring structure. a is an integer from 2 to 4. X is a counterion or a neutral molecule, and b is an integer from 0 to 1. In the case of multiple Xs, each of them can be the same or different. O is an oxygen atom bonded to at least one copper atom.

[0116] In the above formula (2), R6 , preferably a hydrogen atom, an alkyl group or an alkoxy group. 6 In the case of an alkyl group, an alkyl group having 1 to 10 carbon atoms is more preferred, and an n-butyl group is even more preferred. 6 In the case of an alkoxy group, an alkoxy group having 1 to 10 carbon atoms is more preferred, and a methoxy group is even more preferred.

[0117] In the above formula (2), R 7 It is preferably a hydrocarbon group, more preferably an alkyl group or alkenyl group having 1 to 6 carbon atoms, and further preferably an alkenyl group having 1 to 4 carbon atoms. 7 They are bonded to each other to form a ring structure, as two adjacent R 7 The ring structure formed by mutually bonding is preferably a benzene ring.

[0118] In the above formula (2), R 8 Preferred is a hydrogen atom.

[0119] In the above formula (2), Q 3 and Q 4 The aromatic ring contained in the monovalent group represented by includes an aromatic hydrocarbon ring group and an aromatic heterocyclic group. 3 and Q 4 The aromatic heterocyclic group of the aromatic ring contained in the monovalent group represented by is preferably an aromatic heterocyclic group containing a nitrogen atom or an aromatic heterocyclic group containing a sulfur atom. 3 With Q 4 When they are bonded to each other to form a ring structure, the ring structure is preferably an atomic group remaining after removing two hydrogen atoms from phenanthroline, for example.

[0120] In the above formula (2), preferred embodiments of a, X, and b are the same as preferred embodiments of a, X, and b in formula (1).

[0121] From the viewpoint of ethylene selectivity, the carbon dioxide reduction catalyst is preferably a compound represented by the following formula (3).

[0122] [Chemical Formula 14]

[0123]

[0124] In the above formula (3), R 9 ~R 13 Each independently represents a hydrogen atom, a substituent or a divalent group, and two adjacent R 9 Two adjacent Rs 10 Two adjacent Rs 11 Two adjacent Rs 12 Each other, and adjacent R 12 With R13 Can bond with each other to form a ring structure. 9 ~R 12 Each may be the same or different. 13 When it is a divalent group, the divalent group can form a bond with another compound represented by the above formula (3) to form a dimer. X is a counterion or a neutral molecule, b is an integer greater than 0, and when there are multiple Xs, each of them may be the same or different.

[0125] In the above formula (3), R 9 , preferably a hydrogen atom, an alkyl group or an alkoxy group. 9 In the case of an alkyl group, an alkyl group having 1 to 10 carbon atoms is more preferred, and an n-butyl group is even more preferred. 9 In the case of an alkoxy group, an alkoxy group having 1 to 10 carbon atoms is more preferred, and a methoxy group is even more preferred.

[0126] In the above formula (3), R 10 It is preferably a hydrocarbon group, more preferably an alkyl group or alkenyl group having 1 to 6 carbon atoms, and further preferably an alkenyl group having 1 to 4 carbon atoms. 10 They are bonded to each other to form a ring structure, as two adjacent R 10 The ring structure formed by mutually bonding is preferably a benzene ring.

[0127] In the above formula (3), R 11 Preferred is a hydrogen atom.

[0128] In the above formula (3), R 12 Preferred is a hydrogen atom.

[0129] In the above formula (3), R 13It is preferably an aromatic hydrocarbon ring group, preferably an unsubstituted or substituted aromatic hydrocarbon group having 30 or less carbon atoms, more preferably an unsubstituted or substituted phenyl group, an unsubstituted or substituted naphthyl group, an unsubstituted or substituted anthracenyl group, or an unsubstituted or substituted pyrenyl group, and further preferably an unsubstituted or substituted phenyl group. Specific examples of the substituent include halogen atoms such as fluorine, chlorine, bromine, and iodine atoms; hydroxyl groups, carboxyl groups, ester groups, mercapto groups, sulfonic acid groups, nitro groups, phosphonic acid groups; silyl groups having an alkyl group having 1 to 4 carbon atoms; methyl groups, ethyl groups, propyl groups, isopropyl groups, cyclopropyl groups, butyl groups, isobutyl groups, tert-butyl groups, pentyl groups, cyclopentyl groups, hexyl groups, cyclohexyl groups, norbornyl groups, nonyl groups, cyclononyl groups, decyl groups, 3,7-dimethyloctyl groups, adamantyl groups, dodecyl groups, cyclododecyl groups, pentadecyl groups, octadecyl groups, and docosyl groups; alkenyl groups, alkynyl groups; and linear, branched, or cyclic alkoxy groups having a total of about 1 to 50 carbon atoms, such as methoxy groups, ethoxy groups, propoxy groups, butoxy groups, pentyloxy groups, cyclohexyl groups, norbornyloxy groups, decyl groups, and dodecyloxy groups. The number of substituents may be any number as long as the substituent is possible, and is 1 to 5 for a phenyl group, 1 to 7 for a naphthyl group, and 1 to 9 for each of anthracenyl and pyrenyl groups.

[0130] In the above formula (3), preferred embodiments of X and b are the same as preferred embodiments of X and b in formula (1).

[0131] From the viewpoint of ethylene selectivity, the carbon dioxide reduction catalyst is preferably a compound represented by the following formula (4).

[0132] [Chemical Formula 15]

[0133]

[0134] In the above formula (4), R 14 ~R 16 Each independently represents a hydrogen atom or a substituent, and two adjacent R 14 Two adjacent Rs 15 Each other, and adjacent R 15 With R 16 Can be connected to form a ring. There are multiple R 14 ~R 16 Each of them may be the same or different. X is a counter ion or a neutral molecule, b is an integer greater than or equal to 0, and when there are a plurality of Xs, each of them may be the same or different.

[0135] In the above formula (4), R 14 Preferably, it is a hydrogen atom, an alkyl group or an alkoxy group. 14In the case of an alkyl group, an alkyl group having 1 to 10 carbon atoms is more preferred, and an n-butyl group is even more preferred. 14 In the case of an alkoxy group, an alkoxy group having 1 to 10 carbon atoms is more preferred, and a methoxy group is even more preferred.

[0136] In the above formula (4), R 15 Preferred is a hydrogen atom.

[0137] In the above formula (4), R 16 It is preferably an aromatic hydrocarbon ring group, preferably an unsubstituted or substituted aromatic hydrocarbon group having 30 or less carbon atoms, more preferably an unsubstituted or substituted phenyl group, an unsubstituted or substituted naphthyl group, an unsubstituted or substituted anthracenyl group, or an unsubstituted or substituted pyrenyl group, and further preferably an unsubstituted or substituted phenyl group. Specific examples of the substituent include halogen atoms such as fluorine, chlorine, bromine, and iodine atoms; hydroxyl groups, carboxyl groups, ester groups, mercapto groups, sulfonic acid groups, nitro groups, phosphonic acid groups; silyl groups having an alkyl group having 1 to 4 carbon atoms; methyl groups, ethyl groups, propyl groups, isopropyl groups, cyclopropyl groups, butyl groups, isobutyl groups, tert-butyl groups, pentyl groups, cyclopentyl groups, hexyl groups, cyclohexyl groups, norbornyl groups, nonyl groups, cyclononyl groups, decyl groups, 3,7-dimethyloctyl groups, adamantyl groups, dodecyl groups, cyclododecyl groups, pentadecyl groups, octadecyl groups, and docosyl groups; alkenyl groups, alkynyl groups; and linear, branched, or cyclic alkoxy groups having a total of about 1 to 50 carbon atoms, such as methoxy groups, ethoxy groups, propoxy groups, butoxy groups, pentyloxy groups, cyclohexyl groups, norbornyloxy groups, decyl groups, and dodecyloxy groups. The number of substituents may be any number as long as the substituent is possible, and is 1 to 5 for a phenyl group, 1 to 7 for a naphthyl group, and 1 to 9 for each of anthracenyl and pyrenyl groups.

[0138] In the above formula (4), preferred embodiments of X and b are the same as preferred embodiments of X and b in formula (1).

[0139] From the viewpoint of ethylene selectivity, the carbon dioxide reduction catalyst is preferably a compound represented by the following formula (5).

[0140] [Chemical Formula 16]

[0141]

[0142] In the above formula (5), R 17 ~R 21 Each independently represents a hydrogen atom or a substituent, and two adjacent R 17 Two adjacent Rs 18 Two adjacent Rs 19 Two adjacent Rs20 Each other, and the two adjacent R 21 They can be connected to each other to form a ring. 17 ~R 21 Each of them may be the same or different. X is a counter ion or a neutral molecule, b is an integer greater than or equal to 0, and when there are a plurality of Xs, each of them may be the same or different.

[0143] In the above formula (5), R 17 Preferably, it is a hydrogen atom, an alkyl group or an alkoxy group. 17 In the case of an alkyl group, an alkyl group having 1 to 10 carbon atoms is more preferred, and an n-butyl group is even more preferred. 17 In the case of an alkoxy group, an alkoxy group having 1 to 10 carbon atoms is more preferred, and a methoxy group is even more preferred.

[0144] In the above formula (5), R 18 It is preferably a hydrocarbon group, more preferably an alkyl group or alkenyl group having 1 to 6 carbon atoms, and further preferably an alkenyl group having 1 to 4 carbon atoms. 18 They are bonded to each other to form a ring structure, as two adjacent R 18 The ring structure formed by mutually bonding is preferably a benzene ring.

[0145] In the above formula (5), R 19 Preferred is a hydrogen atom.

[0146] In the above formula (5), R 20 It is preferably a hydrocarbon group, more preferably an alkyl group or alkenyl group having 1 to 6 carbon atoms, and further preferably an alkenyl group having 1 to 4 carbon atoms. 20 They are bonded to each other to form a ring structure, as two adjacent R 20 The ring structure formed by mutually bonding is preferably a benzene ring.

[0147] In the above formula (5), R 21 Preferred is a hydrogen atom.

[0148] In the above formula (5), preferred embodiments of X and b are the same as preferred embodiments of X and b in formula (1).

[0149] From the viewpoint of ethylene selectivity, the carbon dioxide reduction catalyst is preferably a compound represented by the following formula (6).

[0150] [Chemical Formula 17]

[0151]

[0152] In formula (6), R 22 ~R26 Each independently represents a hydrogen atom or a substituent, and two adjacent R 22 Two adjacent Rs 23 Two adjacent Rs 24 Two adjacent Rs 26 Each other, and adjacent R 25 With R 26 Can bond with each other to form a ring structure. 22 ~R 26 Each of them may be the same or different. X is a counter ion or a neutral molecule, b is an integer greater than or equal to 0, and when there are a plurality of Xs, each of them may be the same or different.

[0153] In the above formula (6), R 22 Preferably, it is a hydrogen atom, an alkyl group or an alkoxy group. 22 In the case of an alkyl group, an alkyl group having 1 to 10 carbon atoms is more preferred, and an n-butyl group is even more preferred. 22 In the case of an alkoxy group, an alkoxy group having 1 to 10 carbon atoms is more preferred, and a methoxy group is even more preferred.

[0154] In the above formula (6), R 23 It is preferably a hydrocarbon group, more preferably an alkyl group or alkenyl group having 1 to 6 carbon atoms, and further preferably an alkenyl group having 1 to 4 carbon atoms. 23 They are bonded to each other to form a ring structure, as two adjacent R 23 The ring structure formed by mutually bonding is preferably a benzene ring.

[0155] In the above formula (6), R 24 and R 25 Preferred is a hydrogen atom.

[0156] In the above formula (6), R 26 It is preferably a hydrocarbon group, more preferably an alkyl group or alkenyl group having 1 to 6 carbon atoms, and further preferably an alkenyl group having 1 to 4 carbon atoms. 26 They are bonded to each other to form a ring structure, as two adjacent R 26 The ring structure formed by mutually bonding is preferably a benzene ring.

[0157] In the above formula (6), preferred embodiments of X and b are the same as preferred embodiments of X and b in formula (1).

[0158] From the viewpoint of ethylene selectivity, the carbon dioxide reduction catalyst is preferably a compound represented by the following formula (7).

[0159] [Chemical Formula 18]

[0160]

[0161] In the above formula (7), R 27 ~R 34 Each independently represents a hydrogen atom or a substituent, and two adjacent R 27 Two adjacent Rs 28 Two adjacent Rs 29 Two adjacent Rs 30 Two adjacent Rs 31 Two adjacent Rs 32 Two adjacent Rs 33 Each other, and the two adjacent R 34 They can bond with each other to form a ring structure. 27 ~R 34 Each of these may be the same or different. Ar represents a divalent aromatic group which may have a substituent. a is an integer from 2 to 4. X is a counterion or a neutral molecule, and b is an integer from 0 to 1. In the case of a plurality of Xs, each may be the same or different. O is an oxygen atom bonded to at least one copper atom.

[0162] In the above formula (7), R 27 and R 31 Preferably, it is a hydrogen atom, an alkyl group or an alkoxy group. 27 and R 31 In the case of an alkyl group, an alkyl group having 1 to 10 carbon atoms is more preferred, and an n-butyl group is even more preferred. 27 and R 31 In the case of an alkoxy group, an alkoxy group having 1 to 10 carbon atoms is more preferred, and a methoxy group is even more preferred.

[0163] In the above formula (7), R 28 It is preferably a hydrocarbon group, more preferably an alkyl group or alkenyl group having 1 to 6 carbon atoms, and further preferably an alkenyl group having 1 to 4 carbon atoms. 28 They are bonded to each other to form a ring structure, as two adjacent R 28 The ring structure formed by mutually bonding is preferably a benzene ring.

[0164] In the above formula (7), R 32 It is preferably a hydrocarbon group, more preferably an alkyl group or alkenyl group having 1 to 6 carbon atoms, and further preferably an alkenyl group having 1 to 4 carbon atoms. 32 They are bonded to each other to form a ring structure, as two adjacent R 32 The ring structure formed by mutually bonding is preferably a benzene ring.

[0165] In the above formula (7), R 29 and R 33 Preferred is a hydrogen atom.

[0166] In the above formula (7), R 30 and R 34 Preferred is a hydrogen atom.

[0167] In the above formula (7), a is preferably 4.

[0168] In the above formula (7), preferred embodiments of X and b are the same as preferred embodiments of X and b in formula (1).

[0169] The specific structural formula of the carbon dioxide reduction catalyst is shown below, but is not limited thereto. It should be noted that in the following structural formula, "Me" represents a methyl group, "Et" represents an ethyl group, "t-Bu" represents an n-butyl group, "TMS" represents a trimethylsilyl group, "i-Pr" refers to an isopropyl group, "-OAc" refers to an acetate anion, and the valence of copper is divalent (Cu 2+ ).

[0170] [Chemical Formula 19]

[0171]

[0172] [Chemical Formula 20]

[0173]

[0174] [Chemical Formula 21]

[0175]

[0176] [Chemical Formula 22]

[0177]

[0178] [Chemical Formula 23]

[0179]

[0180] [Chemical Formula 24]

[0181]

[0182] [Chemical Formula 25]

[0183]

[0184] [Chemical Formula 26]

[0185]

[0186] [Chemical Formula 27]

[0187]

[0188] [Chemical Formula 28]

[0189]

[0190] [Chemical Formula 29]

[0191]

[0192] [Chemical formula 30]

[0193]

[0194] [Chemical Formula 31]

[0195]

[0196] [Chemical Formula 32]

[0197]

[0198] [Chemical Formula 33]

[0199]

[0200] [Chemical Formula 34]

[0201]

[0202] [Chemical Formula 35]

[0203]

[0204] [Chemical Formula 36]

[0205]

[0206] [Chemical Formula 37]

[0207]

[0208] [Chemical Formula 38]

[0209]

[0210] [Chemical Formula 39]

[0211]

[0212] [Chemical Formula 40]

[0213]

[0214] [Chemical Formula 41]

[0215]

[0216] (Step of reacting carbon dioxide with water)

[0217] The method for producing ethylene according to the present disclosure includes a step of reacting carbon dioxide with water in the presence of a carbon dioxide reduction catalyst.

[0218] This process is not particularly limited as long as it is a process that can react carbon dioxide with water in the presence of a carbon dioxide reduction catalyst. From the perspective of ethylene selectivity, it is preferably carried out using the following carbon dioxide reduction device, which comprises: an oxidation electrode; the carbon dioxide reduction electrode involved in the present disclosure; a membrane separating the aforementioned oxidation electrode from the aforementioned carbon dioxide reduction electrode; an electrolyte; and a power supply connected to the aforementioned oxidation electrode and the aforementioned carbon dioxide reduction electrode.

[0219] It should be noted that the details of the carbon dioxide reduction device will be described later.

[0220] As a method for reacting carbon dioxide and water using a carbon dioxide reduction device, the following method can be cited: a current is passed through an oxidation electrode and a carbon dioxide reduction electrode, carbon dioxide is flowed into the device in a manner such that it contacts the carbon dioxide reduction electrode, and water contained in the electrolyte of the carbon dioxide reduction device reacts with carbon dioxide on the carbon dioxide reduction electrode.

[0221] <Carbon Dioxide Reduction Electrode>

[0222] The carbon dioxide reduction electrode of the present disclosure comprises a multinuclear copper complex and the distance between copper atoms calculated by density functional method is The following carbon dioxide reduction catalyst, or a conductive material of the carbon dioxide reduction catalyst represented by the above formula (1).

[0223] (Conductive material)

[0224] The conductive material supports a carbon dioxide reduction catalyst.

[0225] The carbon dioxide reduction catalyst contained in the carbon dioxide reduction electrode according to the present disclosure is preferably the same as the carbon dioxide reduction catalyst used in the method for producing ethylene according to the present disclosure.

[0226] The conductive material is preferably a porous carbon material.

[0227] Examples of the conductive material include Norit, Ketjen Black, Vulcan, Black Pearl, carbon particles such as acetylene black, fullerenes such as C60 and C70, carbon nanotubes, carbon nanohorns, carbon fibers, graphene, graphene oxide, reduced graphene oxide, and graphene mesoporous sponge.

[0228] As a method for supporting the carbon dioxide reduction catalyst on the conductive material, it is preferable to perform ultrasonic treatment on a dispersion obtained by adding the conductive material to a solution in which the carbon dioxide reduction catalyst is dissolved.

[0229] The amount of the carbon dioxide reduction catalyst supported on the conductive material is preferably such that the mass of copper atoms relative to the mass of the conductive material is from 1 mass % to 50 mass %, more preferably such that the mass of copper atoms is from 2 mass % to 10 mass %.

[0230] The amount of the carbon dioxide reduction catalyst supported on the conductive material is preferably an amount such that the mass of the carbon dioxide reduction catalyst relative to the mass of the conductive material is 1 mass % to 100 mass %, and more preferably an amount such that the mass of the carbon dioxide reduction catalyst is 5 mass % to 50 mass %.

[0231] The mass of copper atoms relative to the mass of the conductive material was measured using a thermogravimetric differential thermal (TG-DTA) analyzer. The measurement method is as shown in the following steps.

[0232] This can be carried out by using a thermogravimetric differential thermal analyzer, heating the sample from 25°C or less to 900°C at a heating rate of 10°C / min in the atmosphere, and measuring a TG-DTA curve.

[0233] (Supporting Body)

[0234] The carbon dioxide reduction electrode according to the present disclosure preferably further includes a support that supports the conductive material.

[0235] The support preferably has conductivity, and examples thereof include carbon nanotubes, graphene, carbon black, carbon cloth, carbon paper, glassy carbon, graphite, and tantalum (Ta).

[0236] (Ionic Conductor)

[0237] The carbon dioxide reduction electrodes contemplated by the present disclosure preferably comprise an ion conductor.

[0238] Examples of ion conductors include ionomers.

[0239] Ionomers are polymers that have been neutralized by ions.

[0240] The ionomer is preferably a polymer neutralized with a cation such as a metal (cationic ionomer) or a polymer neutralized with an anion (anionic ionomer).

[0241] Examples of the anionic ionomer include Sustanion manufactured by Dioxide Materials, AEMION manufactured by Ionomer Innovations, Fumasep manufactured by FumaTech, and Orion manufactured by Orion.

[0242] The ion conductor preferably accounts for 10% by mass or more and 200% by mass or less based on the mass of the conductive material supporting the carbon dioxide reduction catalyst.

[0243] (Other ingredients)

[0244] The carbon dioxide reduction electrode according to the present disclosure may include other components in addition to the conductive material, the support, and the ion conductor.

[0245] Other components include, for example, hydrophobic materials, etc. Examples of hydrophobic materials include fluorine-containing resins, silicone-containing resins, silane coupling agents, waxes, etc. From the perspective of hydrophobic effect, fluorine-containing resins are preferred, and examples of fluorine-containing resins include polytetrafluoroethylene.

[0246] (Method for Manufacturing Carbon Dioxide Reduction Electrode)

[0247] The carbon dioxide reduction electrode of the present disclosure is preferably produced by dispersing a conductive material carrying a carbon dioxide reduction catalyst, an ion conductor added as needed, and other components in a solvent to prepare an electrode ink, applying the electrode ink to a support, and drying the ink.

[0248] (An example of a carbon dioxide reduction electrode)

[0249] Figure 1 An example of the carbon dioxide reduction electrode according to the present disclosure is shown.

[0250] Figure 1 This is a schematic cross-sectional view of the carbon dioxide reduction electrode involved in the present disclosure.

[0251] Figure 1 In the embodiment, the carbon dioxide reduction electrode 10 includes a layer 1 containing a conductive material supporting a carbon dioxide reduction catalyst on a support 2 .

[0252] When components other than the ion conductor are contained, these components are contained in the layer 1 containing the conductive material supporting the carbon dioxide reduction catalyst.

[0253] <Carbon Dioxide Reduction Device>

[0254] The carbon dioxide reduction device according to the present disclosure includes: an oxidation electrode; the carbon dioxide reduction electrode according to the present disclosure; a membrane separating the oxidation electrode and the carbon dioxide reduction electrode; an electrolyte; and a power source connected to the oxidation electrode and the carbon dioxide reduction electrode.

[0255] (An example of a carbon dioxide reduction device)

[0256] Figure 2 An example of the carbon dioxide reduction device according to the present disclosure is shown.

[0257] Figure 2 In the embodiment, carbon dioxide reduction device 100 includes: an oxidation electrode 11; a carbon dioxide reduction electrode 10; a membrane 12 separating the oxidation electrode 11 from the carbon dioxide reduction electrode 10; an electrolyte 13; and a power supply 14 connected to the oxidation electrode 11 and the carbon dioxide reduction electrode 10. Furthermore, carbon dioxide reduction device 100 includes: an electrolytic cell 15 including these components; and a reaction cell 16.

[0258] Here, the carbon dioxide reduction electrode 10 is preferably provided so that the conductive material carrying the carbon dioxide reduction catalyst is in contact with the electrolyte 13 .

[0259] The carbon dioxide reduction device 100 can be used to reduce carbon dioxide to produce ethylene. When used for this reaction, a power source 14 is preferably used to direct current from the carbon dioxide reduction electrode 10 to the oxidation electrode 11. Furthermore, the carbon dioxide is preferably directed into the reaction tank 16 in the direction of arrow A. The carbon dioxide flowing into the reaction tank 16 contacts the carbon dioxide reduction catalyst in the carbon dioxide reduction electrode 10. In this manner, the reaction represented by the following reaction formula 1 proceeds on the carbon dioxide reduction electrode 10 side, while the reaction represented by the following reaction formula 2 proceeds on the oxidation electrode 11 side.

[0260] Reaction 1: 2CO2 + 8H2O + 12e - →C2H4+12OH -

[0261] Reaction 2: 12OH - →3O2+6H2O+12e -

[0262] Then, the generated ethylene flows out from the reaction tank 16 in the direction of arrow B.

[0263] The carbon dioxide reduction electrode will be described in detail below.

[0264] (Oxidation Electrode)

[0265] Examples of the oxidation electrode include platinum, stainless steel, aluminum, copper, nickel, iron, titanium, and carbon, with platinum being preferred. The shape of the oxidation electrode is, for example, foil or mesh.

[0266] (Carbon dioxide reduction electrode)

[0267] The carbon dioxide reduction electrode may be the carbon dioxide reduction electrode mentioned in the present disclosure.

[0268] (membrane)

[0269] The membrane separating the oxidation electrode from the carbon dioxide reduction electrode is preferably an ion exchange membrane.

[0270] The ion exchange membrane is preferably an anion exchange membrane.

[0271] As the ion exchange membrane, for example, Sustainion RX37-50 Grade RT manufactured by Dioxide Materials can be used.

[0272] (Electrolyte)

[0273] Examples of the electrolyte solution include electrolyte solutions containing cations such as sodium ions and potassium ions, anions such as hydroxide ions, bicarbonate ions, and carbonate ions, and water.

[0274] The ion concentration of the electrolyte solution is preferably 0.01 mol / L or more and 5.0 mol / L or less, and more preferably 0.5 mol / L or more and 2.0 mol / L or less.

[0275] (power supply)

[0276] A power supply is connected to the oxidation electrode and the carbon dioxide reduction electrode.

[0277] The power source is not particularly limited as long as it can flow current between the carbon dioxide reduction electrode and the oxidation electrode.

[0278] As the power source, for example, an electrochemical analyzer 701C manufactured by BAS can be used.

[0279] Example

[0280] The following examples are described, but the present invention is not limited by these examples. It should be noted that in the following description, "parts" and "%" are based on mass unless otherwise specified.

[0281] Hereinafter, "TMEDA" refers to N,N,N',N'-tetramethylethylenediamine, "MTBE" refers to tert-butyl methyl ether, "THF" refers to tetrahydrofuran, "OAc" refers to acetate anion, "DMSO" refers to dimethyl sulfoxide, "PhCHO" refers to benzaldehyde, and "PhNH+ Me2B(C6F5)4 - ” refers to N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate.

[0282] For NMR measurement, an AV NEO 300 MHz NMR spectrometer manufactured by Bruker was used. For ESI-MS measurement, a 6130 LCMSD manufactured by Agilent was used.

[0283] <<Example 1>>

[0284] <Synthesis of Carbon Dioxide Reduction Catalyst>

[0285] The carbon dioxide reduction catalyst was synthesized according to the following steps.

[0286] (Synthesis of Compound 3)

[0287] According to the reaction formula shown below, compound 3 was synthesized.

[0288] [Chemical Formula 42]

[0289]

[0290] After placing a nitrogen atmosphere in the reaction vessel, 135 mL of MTBE, 63.80 g (388 mmol) of 4-tert-butylanisole, and 38.69 g (333 mmol) of TMEDA were added dropwise, and the mixture was cooled to 0°C. To this mixture, 212.07 mL (1.6 mol / L, 333 mmol as n-butyllithium) of a hexane solution of n-butyllithium was added dropwise, the temperature was raised to 45°C, and the mixture was stirred for 1.5 hours to obtain a lithiation reaction solution. In another reaction vessel, a nitrogen atmosphere was placed, and 10.00 g (55.5 mmol) of anhydrous 1,10-phenanthroline was suspended in 113 mL of THF at room temperature. This suspension was added dropwise to the lithiation reaction solution, the temperature was raised to 65°C, and the mixture was stirred under reflux for 2 hours to obtain an arylation reaction solution. To the arylation reaction solution cooled to room temperature, 100 g of a 20% by mass aqueous solution of ammonium chloride was added dropwise. The mixture was stirred for 30 minutes, washed, and the aqueous phase was removed, followed by concentration of the organic phase under reduced pressure. A nitrogen atmosphere was placed in another reaction vessel, and 12.00 g (111 mmol) of p-benzoquinone was dissolved in 113 mL of THF at room temperature. This solution was added dropwise to the concentrated organic phase, and stirred at room temperature for 30 minutes to obtain an oxidation reaction solution containing Compound 2.

[0291] After nitrogen atmosphere was placed in another reaction vessel, 11.35 g (83.2 mmol) of zinc chloride was suspended in 113 mL of THF at room temperature. The suspension was added dropwise to the oxidation reaction solution at room temperature. The resulting suspension was cooled to 0° C. and stirred for 4 hours. Then, it was filtered at 0° C., washed with THF, and dried under reduced pressure to obtain compound 3 with a yield of 55%. The identification data of the obtained compound 3 are shown below.

[0292] 1 H-NMR (300MHz, CDCl3): δ (ppm) = 1.37 (s, 18H), 3.76 (s, 6H), 6.98 (d, J = 9.0Hz, 2H), 7.52 (dd, J = 9. 0Hz, 2.4Hz, 2H), 7.87 (d, J=2.4Hz, 2H), 8.02 (d, J=8.4Hz, 2H), 8.02 (s, 2H), 8.50 (d, J=8.4Hz, 2H)

[0293] (Synthesis of Compound 4)

[0294] According to the reaction formula shown below, compound 4 was synthesized.

[0295] [Chemical Formula 43]

[0296]

[0297] After placing a nitrogen atmosphere in the reaction vessel, 8.00 g (12.48 mmol) of compound 3 was added to 108 mL of chloroform at room temperature and dissolved. 15.96 g (99.85 mol) of bromine was added dropwise while stirring, and the mixture was heated to 45°C and stirred for 6 hours to obtain a bromination reaction solution. In another reaction vessel, a nitrogen atmosphere was placed, and 10.39 g (99.85 mmol) of sodium thiosulfate was dissolved in 160 mL of water at room temperature. This aqueous solution was added dropwise to the bromination reaction solution cooled to 0°C, stirred for 1 hour, and then washed. The aqueous phase was removed. In another reaction vessel, a nitrogen atmosphere was placed, and 2.81 g (12.48 mmol) of zinc bromide was dissolved in 151 mL of methanol at room temperature. This solution was added to the washed organic phase, and the mixture was heated to 75°C and concentrated. 202 mL of methanol was added to the mixture, and the mixture was stirred at reflux at 75°C for 1 hour. The mixture was cooled to 0°C and stirred for 1 hour, then filtered, washed with methanol, and dried under reduced pressure to obtain Compound 4 in a yield of 88%. The identification data of the obtained Compound 4 are shown below.

[0298] 1H-NMR (300MHz, CDCl3): δ (ppm) = 1.36 (s, 18H), 3.65 (s, 6H), 7.63 (d, J = 2.4Hz, 2H) , 7.87 (s, 2H), 7.93 (d, J = 2.4Hz, 2H), 8.17 (d, J = 8.1Hz, 2H), 8.31 (d, J = 8.1Hz, 2H)

[0299] (Synthesis of Compound 6)

[0300] According to the reaction formula shown below, compound 6 was synthesized.

[0301] [Chemical Formula 44]

[0302]

[0303] After the reaction vessel is filled with nitrogen atmosphere, 106 mL of THF is added to 4.39 g (110 mmol) of sodium hydride to suspend the mixture. The mixture is heated to 40°C, and 32.67 g (487 mmol) of pyrrole is added dropwise over 20 minutes, followed by stirring for 30 minutes to obtain a reaction solution. After another reaction vessel is filled with nitrogen atmosphere, 19.96 g (146 mmol) of zinc chloride is suspended in 137 mL of THF at room temperature. The suspension is added dropwise to the above reaction solution, stirred for 30 minutes, and then cooled to room temperature. 32.50 g (36.6 mmol) of compound 4 is added thereto. After another reaction vessel is filled with nitrogen atmosphere, 0.082 g (0.37 mmol) of palladium acetate and 0.219 g (0.73 mmol) of 2-(di-tert-butylphosphino)biphenyl are dissolved in 6.5 mL of THF at room temperature to obtain a catalyst solution. This catalyst solution was added dropwise to the reaction solution, and the temperature was raised to 75° C., and the mixture was stirred under reflux for 6 hours, and then cooled to room temperature.

[0304] After nitrogen atmosphere was established in another reaction vessel, 86.23 g of ammonium chloride and 178.15 g (28%, 2930 mmol) of an aqueous ammonia solution were dissolved in 217 mL of water at room temperature. This aqueous solution was added dropwise to the reaction solution, stirred at room temperature for 30 minutes, and then washed. The aqueous phase was removed. To the resulting organic phase, 216 g of a 24.8% by mass aqueous ammonium chloride solution was added dropwise, stirred for 15 minutes, and then washed. The aqueous phase was then removed.

[0305] 79 mL of DMSO was added to the obtained organic phase, the temperature was raised to 82 ° C, and THF was removed by concentrating under reduced pressure. 6.18 g (30.5 mmol) of 1-dodecanethiol and 7.06 g (28%, 36.6 mmol as sodium methoxide) of methanol solution were added dropwise thereto, and stirred at 82 ° C for 6.5 hours. The reaction solution was cooled to 40 ° C and 58.6 mL of MTBE was added. After nitrogen atmosphere was placed in another reaction container, 23.50 g of ammonium chloride and 2.93 g (48.8 mmol) of acetic acid were dissolved in 86.7 mL of water at room temperature. The aqueous solution was added dropwise to the above reaction solution, stirred at 40 ° C for 30 minutes to wash, and the aqueous phase was removed. The obtained organic phase was cooled to 0 ° C, stirred for 2 hours, and then filtered. The obtained crystals were washed with MTBE and methanol in sequence and dried under reduced pressure to obtain compound 6 with a yield of 76%. The identification data of the obtained compound 6 are shown below.

[0306] 1 H-NMR (300MHz, CDCl3): δ (ppm) = 1.40 (s, 18H), 6.25 (m, 2H), 6.44 (m, 2H), 6.74 (m, 2H), 7.84 (s, 2H), 7.89 (s, 2H), 7.92 (s, 2H), 8.35 (d, J = 8.4Hz, 2H), 8.46 (d, J = 8.4Hz, 2H), 10.61 (s, 2H), 15.88 (s, 2H)

[0307] (Synthesis of Compound 8)

[0308] Compound 8 was synthesized according to the reaction formula shown below using the method described in International Publication No. 2019-026883.

[0309] [Chemical Formula 45]

[0310]

[0311] (Synthesis of Oxygen-bridged Binuclear Copper Complex 1)

[0312] According to the reaction formula shown below, the oxy-bridged binuclear copper complex 1 (ie, carbon dioxide reduction catalyst 1) was synthesized.

[0313] [Chemical Formula 46]

[0314]

[0315] After the reaction vessel is filled with nitrogen atmosphere, 29 mL of pre-degassed methanol is added to 1.80 g (9.02 mmol) of copper acetate monohydrate to suspend it. 31 mL of chloroform is added thereto, the temperature is raised to 50 ° C, and a copper acetate solution is prepared. After another reaction vessel is filled with nitrogen atmosphere, a suspension containing 2.50 g (3.61 mmol) of compound 8 and 31 mL of chloroform is prepared. After the suspension is added dropwise to the above-mentioned copper acetate solution, the temperature is raised to 55 ° C, and the mixture is stirred for 1 hour while refluxing to obtain a reaction solution containing oxygen-bridged binuclear copper complex 1. After the reaction solution is cooled to room temperature, it is filtered. The obtained crystals are washed with methanol and dried under reduced pressure to obtain oxygen-bridged binuclear copper complex 1 with a yield of 2.79 g and a yield of 95%. The identification data of the obtained oxygen-bridged binuclear copper complex 1 (carbon dioxide reduction catalyst) are shown below. The results of the ESI-MS determination were confirmed as follows.

[0316] ESI-MS[M-OAc] + :m / z=815.2

[0317] The distance between copper atoms in oxygen-bridged binuclear copper complex 1 is

[0318] The method for calculating the distance between copper atoms is described below, and the method for calculating the distance between copper atoms in the following examples is the same.

[0319] <Fabrication of Carbon Dioxide Reduction Electrode>

[0320] (Synthesis of Conductive Material Supporting Carbon Dioxide Reduction Catalyst)

[0321] 137.84mg (0.157mmol) of oxygen-bridged binuclear copper complex 1 was weighed in a reaction vessel, 105mL of chloroform was added, the mixture was heated to 60°C, and stirring and ultrasonic irradiation were repeated. After confirming that oxygen-bridged binuclear copper complex 1 had dissolved, it was cooled to room temperature to obtain a solution. In another reaction vessel, 400mg of carbon black (KetjenBlack EC600JD manufactured by Lion Specialty Chemicals Co., Ltd.) as a conductive material was weighed, and the above solution was added dropwise thereto to prepare a dispersion. Ultrasonic waves were irradiated to the dispersion for 15 minutes, thereby uniformly dispersing the conductive material supported by a carbon dioxide reduction catalyst, and a suspension having a content of copper atoms of 5% by mass relative to the mass of the carbon black was obtained. After filtering the suspension using a PTFE membrane filter, the suspension was dried under reduced pressure to obtain a conductive material supported by a carbon dioxide reduction catalyst.

[0322] (Fabrication of Carbon Dioxide Reduction Electrode)

[0323] 25.00 mg of the powder of the conductive material supporting the carbon dioxide reduction catalyst and 25.00 mg of PTFE microparticles with a particle size of 1 μm (manufactured by Sigma-Aldrich) were weighed into a screw tube. 2.50 mL of ethanol and 500 mg of a 5% by mass ethanol solution of Sustanion XA-9 (manufactured by Dioxide Materials), an anionic ionomer, were added to prepare a dispersion. Ultrasonic waves were then irradiated on the dispersion for 5 minutes to obtain an ink.

[0324] Carbon paper (25 mm in diameter / GDL36BB manufactured by SIGRACET) was used as a support, and 250 mg of the ink obtained above was applied to the carbon paper and then dried to obtain the carbon dioxide reduction electrode of Example 1.

[0325] <Fabrication of Carbon Dioxide Reduction Device>

[0326] and Figure 2 The carbon dioxide reduction device 100 shown is a carbon dioxide reduction device manufactured in the same manner.

[0327] A platinum mesh was used as the oxidation electrode 11. The carbon dioxide reduction electrode of Example 1 was used as the carbon dioxide reduction electrode 10. An anion exchange membrane (Sustainion RX37-50 Grade RT manufactured by Dioxide Materials) was used as the membrane 12. A 1.0 M aqueous potassium hydroxide solution was used as the electrolyte 13. An electrochemical measuring device (BAS Electrochemical Analyzer 701C) was used as the power source 14. Furthermore, an Ag / AgCl reference electrode (manufactured by EC FRONTIER CO., LTD.) was placed in the electrolyte 13 between the membrane 12 and the carbon dioxide reduction electrode 10.

[0328] <Manufacturing of Ethylene>

[0329] Carbon dioxide gas humidified by passing through a washing bottle filled with 60°C water was circulated in the direction of arrow A of the reaction vessel 16. The gas inflow was set to 5 mL / min using a mass flow controller (GF40 manufactured by Brooks).

[0330] Using an electrochemical measuring device, a constant potential of −2.2 V relative to a reversible hydrogen electrode (RHE) was applied to the carbon dioxide reduction electrode 10 to produce ethylene.

[0331] <<Example 2>>

[0332] <Manufacturing of Ethylene>

[0333] Ethylene was synthesized by the same procedure as in Example 1 except that a constant potential of -3.2 V vs. reversible hydrogen electrode (RHE) was applied.

[0334] <<Example 3>>

[0335] (Synthesis of Oxygen-bridged Binuclear Copper Complex 2)

[0336] Using compound 10 synthesized by the method described in International Publication No. 2009-084283, an oxy-bridged binuclear copper complex 2 (ie, carbon dioxide reduction catalyst 2) was synthesized according to the reaction formula shown below.

[0337] [Chemical Formula 47]

[0338]

[0339] After the reaction vessel is in a nitrogen atmosphere, 29 mL of pre-degassed methanol is added to 0.69 g (3.48 mmol) of copper acetate monohydrate to suspend it. 31 mL of chloroform is added thereto, the temperature is raised to 50 ° C, and a copper acetate solution is prepared. After another reaction vessel is in a nitrogen atmosphere, a suspension comprising 1.0 g (1.39 mmol) of compound 10 and 31 mL of chloroform is prepared. After the suspension is added dropwise to the above-mentioned copper acetate solution, the temperature is raised to 55 ° C, and the mixture is stirred for 1 hour while refluxing to obtain a reaction solution comprising an oxygen-bridged binuclear copper complex 2. After the reaction solution is cooled to room temperature, it is filtered. The obtained crystals are washed with methanol and dried under reduced pressure to obtain an oxygen-bridged binuclear copper complex 2 with a yield of 1.25 g and a yield of 98%. The identification data of the obtained oxygen-bridged binuclear copper complex 2 (carbon dioxide reduction catalyst) are shown below. The results of the ESI-MS determination were confirmed as follows.

[0340] ESI-MS[M-OAc] + :m / z=841.17

[0341] The distance between copper atoms in oxygen-bridged binuclear copper complex 2 is

[0342] <Fabrication of Carbon Dioxide Reduction Electrode>

[0343] The carbon dioxide reduction electrode of Example 3 was obtained by the same procedure as in Example 1 except that the oxygen-bridged binuclear copper complex 2 was used instead of the oxygen-bridged binuclear copper complex 1.

[0344] <Fabrication of Carbon Dioxide Reduction Device>

[0345] A carbon dioxide reduction device was obtained by the same procedure as in Example 1, except that the carbon dioxide reduction electrode of Example 3 was used instead of the carbon dioxide reduction electrode of Example 1.

[0346] <Manufacturing of Ethylene>

[0347] Ethylene was synthesized by the same procedure as in Example 2, except that the carbon dioxide reduction apparatus of Example 3 was used instead of the carbon dioxide reduction apparatus of Example 1.

[0348] <<Example 4>>

[0349] (Synthesis of Oxygen-bridged Binuclear Copper Complex 3)

[0350] Using compound 11 synthesized by the method described in International Publication No. 2009-084283, an oxy-bridged binuclear copper complex 3 (ie, carbon dioxide reduction catalyst 3) was synthesized according to the reaction formula shown below.

[0351] [Chemical Formula 48]

[0352]

[0353] After the reaction vessel is in a nitrogen atmosphere, 29 mL of pre-degassed methanol is added to 0.64 g (3.19 mmol) of copper acetate monohydrate to suspend it. 31 mL of chloroform is added thereto, and the temperature is raised to 50 ° C to prepare a copper acetate solution. After another reaction vessel is in a nitrogen atmosphere, a suspension comprising 1.0 g (1.28 mmol) of compound 11 and 31 mL of chloroform is prepared. After the suspension is added dropwise to the above-mentioned copper acetate solution, the temperature is raised to 55 ° C and stirred for 1 hour while refluxing to obtain a reaction solution comprising an oxygen-bridged binuclear copper complex 3. After the reaction solution is cooled to room temperature, it is filtered. The obtained crystals are washed with methanol and dried under reduced pressure to obtain an oxygen-bridged binuclear copper complex 3 with a yield of 1.23 g and a yield of 42%. The identification data of the obtained oxygen-bridged binuclear copper complex 3 (carbon dioxide reduction catalyst 3) are shown below. The results of the ESI-MS determination were confirmed as follows.

[0354] ESI-MS[M+H] + :m / z=906.1

[0355] The distance between copper atoms in oxygen-bridged binuclear copper complex 3 is

[0356] <Fabrication of Carbon Dioxide Reduction Electrode>

[0357] The carbon dioxide reduction electrode of Example 4 was obtained by the same procedure as in Example 1 except that the oxygen-bridged binuclear copper complex 3 was used instead of the oxygen-bridged binuclear copper complex 1.

[0358] <Fabrication of Carbon Dioxide Reduction Device>

[0359] A carbon dioxide reduction device was obtained by the same procedure as in Example 1, except that the carbon dioxide reduction electrode of Example 4 was used instead of the carbon dioxide reduction electrode of Example 1.

[0360] <Manufacturing of Ethylene>

[0361] Ethylene was synthesized by the same procedure as in Example 2, except that the carbon dioxide reduction apparatus of Example 4 was used instead of the carbon dioxide reduction apparatus of Example 1.

[0362] <<Example 5>>

[0363] (Synthesis of Oxygen-bridged Binuclear Copper Complex 4)

[0364] Using compound 12 synthesized by the method described in International Publication No. 2009-084283, an oxy-bridged binuclear copper complex 4 (ie, carbon dioxide reduction catalyst 4) was synthesized according to the reaction formula shown below.

[0365] [Chemical Formula 49]

[0366]

[0367] After the reaction vessel is in a nitrogen atmosphere, 29 mL of pre-degassed methanol is added to 0.66 g (3.29 mmol) of copper acetate monohydrate to suspend it. 31 mL of chloroform is added thereto, the temperature is raised to 50 ° C, and a copper acetate solution is prepared. After another reaction vessel is in a nitrogen atmosphere, a suspension comprising 1.0 g (1.31 mmol) of compound 12 and 31 mL of chloroform is prepared. After the suspension is added dropwise to the above-mentioned copper acetate solution, the temperature is raised to 55 ° C, and the mixture is stirred for 1 hour while refluxing to obtain a reaction solution comprising an oxygen-bridged binuclear copper complex 4. After the reaction solution is cooled to room temperature, it is filtered. The obtained crystals are washed with methanol and dried under reduced pressure to obtain an oxygen-bridged binuclear copper complex 4 with a yield of 1.24 g and a yield of 100%. The identification data of the obtained oxygen-bridged binuclear copper complex 4 (carbon dioxide reduction catalyst) are shown below. The results of the ESI-MS determination were confirmed as follows.

[0368] ESI-MS[M-OAc] + :m / z=883.16

[0369] The distance between copper atoms in oxygen-bridged binuclear copper complex 4 is

[0370] <Fabrication of Carbon Dioxide Reduction Electrode>

[0371] The carbon dioxide reduction electrode of Example 5 was obtained by the same procedure as in Example 1 except that the oxygen-bridged binuclear copper complex 4 was used instead of the oxygen-bridged binuclear copper complex 1.

[0372] <Fabrication of Carbon Dioxide Reduction Device>

[0373] A carbon dioxide reduction device was obtained by the same procedure as in Example 1, except that the carbon dioxide reduction electrode of Example 5 was used instead of the carbon dioxide reduction electrode of Example 1.

[0374] <Manufacturing of Ethylene>

[0375] Ethylene was synthesized by the same procedure as in Example 2, except that the carbon dioxide reduction apparatus of Example 5 was used instead of the carbon dioxide reduction apparatus of Example 1.

[0376] <<Example 6>>

[0377] (Synthesis of Compound 13)

[0378] Compound 13 was synthesized according to the reaction formula shown below.

[0379] [Chemical Formula 50]

[0380]

[0381] Under a nitrogen atmosphere, 92 ml of dehydrated toluene and 231 mg (0.29 mmol) of N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate were added, and the resulting solution was heated to 80°C while stirring with a stirrer. To this solution was added dropwise a mixture of 1.49 g (9.06 mmol) of aldehyde, 5.0 g (8.24 mmol) of compound 6, and 12 ml of toluene. After stirring for 3 hours, the reaction mixture was allowed to cool gradually to room temperature.

[0382] To the reaction solution was added dropwise a solution prepared by dissolving 0.98 g (9.06 mmol) of benzoquinone in 11 ml of THF. After confirming the completion of the reaction, the resulting reaction solution was filtered to obtain the target compound 13 in a yield of 5.49 g and 99%. The identification data of the resulting compound 13 are shown below. The results of the ESI-MS measurement were confirmed as follows.

[0383] ESI-MS[M+H] + :m / z=751.3

[0384] (Synthesis of Oxygen-bridged Binuclear Copper Complex 5)

[0385] According to the reaction formula shown below, the oxy-bridged binuclear copper complex 5 (ie, carbon dioxide reduction catalyst 5) was synthesized.

[0386] [Chemical Formula 51]

[0387]

[0388] After the reaction vessel is in a nitrogen atmosphere, 29 mL of pre-degassed methanol is added to 0.67 g (3.33 mmol) of copper acetate monohydrate to suspend it. 31 mL of chloroform is added thereto, and the temperature is raised to 50 ° C to prepare a copper acetate solution. After another reaction vessel is in a nitrogen atmosphere, a suspension comprising 1.0 g (1.33 mmol) of compound 13 and 31 mL of chloroform is prepared. After the suspension is added dropwise to the above-mentioned copper acetate solution, the temperature is raised to 55 ° C and stirred for 1 hour while refluxing to obtain a reaction solution comprising an oxygen-bridged binuclear copper complex 5. After the reaction solution is cooled to room temperature, it is filtered. The obtained crystals are washed with methanol and dried under reduced pressure to obtain an oxygen-bridged binuclear copper complex 5 with a yield of 1.16 g and a yield of 93%. The identification data of the obtained oxygen-bridged binuclear copper complex 5 (carbon dioxide reduction catalyst 5) are shown below. The results of the ESI-MS determination were confirmed as follows.

[0389] ESI-MS[M-OAc] + :m / z=873.16

[0390] The distance between copper atoms in oxygen-bridged binuclear copper complex 5 is

[0391] <Fabrication of Carbon Dioxide Reduction Electrode>

[0392] The carbon dioxide reduction electrode of Example 6 was obtained by the same procedure as in Example 1 except that the oxygen-bridged binuclear copper complex 5 was used instead of the oxygen-bridged binuclear copper complex 1.

[0393] <Fabrication of Carbon Dioxide Reduction Device>

[0394] A carbon dioxide reduction device was obtained by the same procedure as in Example 1, except that the carbon dioxide reduction electrode of Example 6 was used instead of the carbon dioxide reduction electrode of Example 1.

[0395] <Manufacturing of Ethylene>

[0396] Ethylene was synthesized by the same procedure as in Example 2, except that the carbon dioxide reduction apparatus of Example 6 was used instead of the carbon dioxide reduction apparatus of Example 1.

[0397] <<Example 7>>

[0398] (Synthesis of Compound 14)

[0399] Compound 14 was synthesized according to the reaction formula shown below.

[0400] [Chemical Formula 52]

[0401]

[0402] Under a nitrogen atmosphere, 92 ml of dehydrated toluene and 231 mg (0.29 mmol) of N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate were added, and the resulting solution was heated to 80°C while stirring with a stirrer. To this solution was added dropwise a mixture of 2.09 g (9.06 mmol) of aldehyde, 5.0 g (8.24 mmol) of compound 6, and 12 ml of toluene. After stirring for 3 hours, the reaction mixture was allowed to cool gradually to room temperature.

[0403] To the reaction solution was added dropwise a solution prepared by dissolving 0.98 g (9.06 mmol) of benzoquinone in 11 ml of THF. After confirming the completion of the reaction, the resulting reaction solution was filtered to obtain the target compound 14 in a yield of 5.89 g and 99%. The identification data of the resulting compound 14 are shown below. The results of the ESI-MS analysis were confirmed as follows.

[0404] ESI-MS[M+H] + :m / z=817.4

[0405] (Synthesis of Oxygen-bridged Binuclear Copper Complex 6)

[0406] According to the reaction formula shown below, the oxygen-bridged binuclear copper complex 6 (ie, carbon dioxide reduction catalyst 6) was synthesized.

[0407] [Chemical Formula 53]

[0408]

[0409] After the reaction vessel is in a nitrogen atmosphere, 29 mL of pre-degassed methanol is added to 0.61 g (3.06 mmol) of copper acetate monohydrate to suspend it. 31 mL of chloroform is added thereto, the temperature is raised to 50 ° C, and a copper acetate solution is prepared. After another reaction vessel is in a nitrogen atmosphere, a suspension comprising 1.0 g (1.22 mmol) of compound 14 and 31 mL of chloroform is prepared. After the suspension is added dropwise to the above-mentioned copper acetate solution, the temperature is raised to 55 ° C, and the mixture is stirred for 1 hour while refluxing to obtain a reaction solution comprising an oxygen-bridged binuclear copper complex 6. After the reaction solution is cooled to room temperature, it is filtered. The obtained crystals are washed with methanol and dried under reduced pressure to obtain an oxygen-bridged binuclear copper complex 6 with a yield of 1.08 g and a yield of 88%. The identification data of the obtained oxygen-bridged binuclear copper complex 6 (carbon dioxide reduction catalyst 6) are shown below. The results of the ESI-MS determination were confirmed as follows.

[0410] ESI-MS[M-OAc] + :m / z=941.20

[0411] The distance between copper atoms in oxygen-bridged binuclear copper complex 6 is

[0412] <Fabrication of Carbon Dioxide Reduction Electrode>

[0413] The carbon dioxide reduction electrode of Example 7 was obtained by the same procedure as in Example 1 except that the oxygen-bridged binuclear copper complex 6 was used instead of the oxygen-bridged binuclear copper complex 1.

[0414] <Fabrication of Carbon Dioxide Reduction Device>

[0415] A carbon dioxide reduction device was obtained by the same procedure as in Example 1, except that the carbon dioxide reduction electrode of Example 7 was used instead of the carbon dioxide reduction electrode of Example 1.

[0416] <Manufacturing of Ethylene>

[0417] Ethylene was synthesized by the same procedure as in Example 2, except that the carbon dioxide reduction apparatus of Example 7 was used instead of the carbon dioxide reduction apparatus of Example 1.

[0418] <<Example 8>>

[0419] (Synthesis of Compound 15)

[0420] Compound 15 was synthesized according to the reaction formula shown below.

[0421] [Chemical Formula 54]

[0422]

[0423] Under a nitrogen atmosphere, 92 ml of dehydrated toluene and 231 mg (0.29 mmol) of N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate were added, and the resulting solution was heated to 80°C while stirring with a stirrer. A mixture of 1.37 g (9.36 mmol) of aldehyde, 5.0 g (8.24 mmol) of compound 6, and 12 ml of toluene was added dropwise to this solution. After stirring for 3 hours, the mixture was allowed to cool, gradually cooling the reaction mixture to room temperature.

[0424] To the reaction solution was added dropwise a solution prepared by dissolving 0.98 g (9.06 mmol) of benzoquinone in 11 ml of THF. After confirming the completion of the reaction, the resulting reaction solution was filtered to obtain the target compound 15 in a yield of 5.59 g and 92%. The identification data of the resulting compound 15 are shown below. The results of the ESI-MS measurement were confirmed as follows.

[0425] ESI-MS[M+H] + :m / z=738.3

[0426] (Synthesis of Oxygen-bridged Binuclear Copper Complex 7)

[0427] According to the reaction formula shown below, the oxy-bridged binuclear copper complex 7 (ie, carbon dioxide reduction catalyst 7) ​​was synthesized.

[0428] [Chemical Formula 55]

[0429]

[0430] After the reaction vessel is in a nitrogen atmosphere, 29 mL of pre-degassed methanol is added to 0.68 g (3.39 mmol) of copper acetate monohydrate to suspend it. 31 mL of chloroform is added thereto, and the temperature is raised to 50 ° C to prepare a copper acetate solution. After another reaction vessel is in a nitrogen atmosphere, a suspension comprising 1.0 g (1.36 mmol) of compound 15 and 31 mL of chloroform is prepared. After the suspension is added dropwise to the above-mentioned copper acetate solution, the temperature is raised to 55 ° C and stirred for 1 hour while refluxing to obtain a reaction solution comprising an oxygen-bridged binuclear copper complex 7. After the reaction solution is cooled to room temperature, it is filtered. The obtained crystals are washed with methanol and dried under reduced pressure to obtain an oxygen-bridged binuclear copper complex 7 with a yield of 1.08 g and a yield of 88%. The identification data of the obtained oxygen-bridged binuclear copper complex 7 (carbon dioxide reduction catalyst 7) ​​are shown below. The results of the ESI-MS determination were confirmed as follows.

[0431] ESI-MS[M-OAc] + :m / z=860.1

[0432] The distance between copper atoms in oxygen-bridged binuclear copper complex 7 is

[0433] <Fabrication of Carbon Dioxide Reduction Electrode>

[0434] The carbon dioxide reduction electrode of Example 8 was obtained by the same procedure as in Example 1 except that the oxygen-bridged binuclear copper complex 7 was used instead of the oxygen-bridged binuclear copper complex 1.

[0435] <Fabrication of Carbon Dioxide Reduction Device>

[0436] A carbon dioxide reduction device was obtained by the same procedure as in Example 1, except that the carbon dioxide reduction electrode of Example 8 was used instead of the carbon dioxide reduction electrode of Example 1.

[0437] <Manufacturing of Ethylene>

[0438] Ethylene was synthesized by the same procedure as in Example 2, except that the carbon dioxide reduction apparatus of Example 8 was used instead of the carbon dioxide reduction apparatus of Example 1.

[0439] <<Example 9>>

[0440] (Synthesis of Oxygen-bridged Binuclear Copper Complex 8)

[0441] Using compound 17 synthesized by the method described in Tetrahedron, 1999, 55, 8377, an oxy-bridged binuclear copper complex 8 (ie, carbon dioxide reduction catalyst 8) was synthesized according to the reaction formula shown below.

[0442] [Chemical Formula 56]

[0443]

[0444] After the reaction vessel is in a nitrogen atmosphere, 2.9 mL of pre-degassed methanol is added to 0.21 g (1.03 mmol) of copper acetate monohydrate to suspend it. 3.1 mL of chloroform is added thereto, and the temperature is raised to 50 ° C to prepare a copper acetate solution. After another reaction vessel is in a nitrogen atmosphere, a suspension containing 0.25 g (0.41 mmol) of compound 17 and 10 mL of chloroform is prepared. After the suspension is added dropwise to the above-mentioned copper acetate solution, the temperature is raised to 55 ° C and stirred for 1 hour while refluxing to obtain a reaction solution containing an oxygen-bridged binuclear copper complex 8. After the reaction solution is cooled to room temperature, it is filtered. The obtained crystals are washed with methanol and dried under reduced pressure to obtain an oxygen-bridged binuclear copper complex 8 with a yield of 0.11 g and a yield of 33%. The identification data of the obtained oxygen-bridged binuclear copper complex 8 (carbon dioxide reduction catalyst 8) are shown below. The results of the ESI-MS determination were confirmed as follows.

[0445] ESI-MS[M-Cl] + :m / z=763.1

[0446] The distance between copper atoms in oxygen-bridged binuclear copper complex 8 is

[0447] <Fabrication of Carbon Dioxide Reduction Electrode>

[0448] The carbon dioxide reduction electrode of Example 9 was obtained by the same procedure as in Example 1 except that the oxygen-bridged binuclear copper complex 8 was used instead of the oxygen-bridged binuclear copper complex 1.

[0449] <Fabrication of Carbon Dioxide Reduction Device>

[0450] A carbon dioxide reduction device was obtained by the same procedure as in Example 1, except that the carbon dioxide reduction electrode of Example 9 was used instead of the carbon dioxide reduction electrode of Example 1.

[0451] <Manufacturing of Ethylene>

[0452] Ethylene was synthesized by the same procedure as in Example 2, except that the carbon dioxide reduction apparatus of Example 9 was used instead of the carbon dioxide reduction apparatus of Example 1.

[0453] <<Example 10>>

[0454] (Synthesis of Oxygen-bridged Binuclear Copper Complex 9)

[0455] Using compound 18 synthesized by the method described in JP-A-2009-173627, an oxy-bridged binuclear copper complex 9 (ie, carbon dioxide reduction catalyst 9) was synthesized according to the reaction formula shown below.

[0456] [Chemical Formula 57]

[0457]

[0458] After the reaction vessel is filled with nitrogen atmosphere, 12 mL of pre-degassed methanol is added to 0.68 g (3.41 mmol) of copper acetate monohydrate to suspend it. 11 mL of chloroform is added thereto and the temperature is raised to 50° C. to prepare a copper acetate solution. After another reaction vessel is filled with nitrogen atmosphere, a suspension containing 1.0 g (1.36 mmol) of compound 18 and 10 mL of chloroform is prepared. After the suspension is added dropwise to the copper acetate solution, the temperature is raised to 55° C. and stirred for 1 hour while refluxing to obtain a reaction solution containing oxygen-bridged binuclear copper complex 9. After the reaction solution is cooled to room temperature, it is filtered. The obtained crystals are washed with methanol and dried under reduced pressure to obtain oxygen-bridged binuclear copper complex 9 with a yield of 0.93 g and a yield of 80%. The identification data of the obtained oxygen-bridged binuclear copper complex 9 (carbon dioxide reduction catalyst 10) are shown below. The results of the ESI-MS determination were confirmed as follows.

[0459] ESI-MS[M+H] + :m / z=855.2

[0460] <Fabrication of Carbon Dioxide Reduction Electrode>

[0461] The carbon dioxide reduction electrode of Example 10 was obtained by the same procedure as in Example 1 except that the oxygen-bridged binuclear copper complex 9 was used instead of the oxygen-bridged binuclear copper complex 1.

[0462] <Fabrication of Carbon Dioxide Reduction Device>

[0463] A carbon dioxide reduction device was obtained by the same procedure as in Example 1, except that the carbon dioxide reduction electrode of Example 10 was used instead of the carbon dioxide reduction electrode of Example 1.

[0464] <Manufacturing of Ethylene>

[0465] Ethylene was synthesized by the same procedure as in Example 2, except that the carbon dioxide reduction apparatus of Example 1 was used instead of the carbon dioxide reduction apparatus of Example 10.

[0466] <<Example 11>>

[0467] (Synthesis of Oxygen-bridged Binuclear Copper Complex 10)

[0468] Using compound 17 synthesized by the method described in Tetrahedron, 1999, 55, 8377, an oxy-bridged binuclear copper complex 10 (ie, carbon dioxide reduction catalyst 10) was synthesized according to the reaction formula shown below.

[0469] [Chemical Formula 58]

[0470]

[0471] After the reaction vessel is filled with nitrogen atmosphere, 5.0 mL of pre-degassed methanol is added to 0.08 g (0.38 mmol) of copper acetate monohydrate to suspend it. 5.0 mL of chloroform is added thereto and the temperature is raised to 50°C to prepare a copper acetate solution. After another reaction vessel is filled with nitrogen atmosphere, a suspension containing 0.1 g (0.19 mmol) of compound 17, 0.03 g (0.19 mmol) of 4,5-dimethyl-1,2-phenylenediamine and 10 mL of chloroform is prepared. After the suspension is added dropwise to the above-mentioned copper acetate solution, the temperature is raised to 65°C and stirred for 3 hours while reflux to obtain a reaction solution containing oxygen-bridged binuclear copper complex 9. After the reaction solution is cooled to room temperature, the solvent is distilled off. The obtained solid is obtained by filtration while washing with acetone and dried under reduced pressure to obtain oxygen-bridged binuclear copper complex 10 with a yield of 0.13 g and a yield of 85%. The identification data of the obtained oxygen-bridged binuclear copper complex 10 (carbon dioxide reduction catalyst 10) are shown below. The results of the ESI-MS measurement were confirmed as follows.

[0472] ESI-MS[M-OAc] + :m / z=815.2

[0473] The distance between copper atoms in oxygen-bridged binuclear copper complex 10 is

[0474] <Fabrication of Carbon Dioxide Reduction Electrode>

[0475] The carbon dioxide reduction electrode of Example 11 was obtained by the same procedure as in Example 1 except that the oxygen-bridged binuclear copper complex 10 was used instead of the oxygen-bridged binuclear copper complex 1.

[0476] <Fabrication of Carbon Dioxide Reduction Device>

[0477] A carbon dioxide reduction device was obtained by the same procedure as in Example 1, except that the carbon dioxide reduction electrode of Example 11 was used instead of the carbon dioxide reduction electrode of Example 1.

[0478] <Manufacturing of Ethylene>

[0479] Ethylene was synthesized by the same procedure as in Example 2, except that the carbon dioxide reduction apparatus of Example 11 was used instead of the carbon dioxide reduction apparatus of Example 1.

[0480] <<Example 12>>

[0481] (Synthesis of Oxygen-bridged Binuclear Copper Complex 11)

[0482] Using compound 17 synthesized by the method described in Tetrahedron, 1999, 55, 8377, an oxy-bridged binuclear copper complex 11 (ie, carbon dioxide reduction catalyst 11) was synthesized according to the reaction formula shown below.

[0483] [Chemical Formula 59]

[0484]

[0485] After the reaction vessel is filled with nitrogen atmosphere, 5.0 mL of pre-degassed methanol is added to 0.08 g (0.38 mmol) of copper acetate monohydrate to suspend it. 5.0 mL of chloroform is added thereto and the temperature is raised to 50°C to prepare a copper acetate solution. After another reaction vessel is filled with nitrogen atmosphere, a suspension containing 0.1 g (0.19 mmol) of compound 17, 0.03 g (0.19 mmol) of 2,3-naphthalenediamine and 10 mL of chloroform is prepared. After the suspension is added dropwise to the above-mentioned copper acetate solution, the temperature is raised to 65°C and stirred for 3 hours while reflux to obtain a reaction solution containing oxygen-bridged binuclear copper complex 10. After the reaction solution is cooled to room temperature, the solvent is distilled off. The obtained solid is obtained by filtration while washing with acetone and dried under reduced pressure to obtain oxygen-bridged binuclear copper complex 11 with a yield of 0.15 g and a yield of 95%. The identification data of the obtained oxygen-bridged binuclear copper complex 11 (carbon dioxide reduction catalyst 11) are shown below. The results of ESI-MS measurement were confirmed as follows.

[0486] ESI-MS[M-OAc] +:m / z=837.2

[0487] The distance between copper atoms in oxygen-bridged binuclear copper complex 11 is

[0488] <Fabrication of Carbon Dioxide Reduction Electrode>

[0489] The carbon dioxide reduction electrode of Example 12 was obtained by the same procedure as in Example 1 except that the oxygen-bridged binuclear copper complex 11 was used instead of the oxygen-bridged binuclear copper complex 1.

[0490] <Fabrication of Carbon Dioxide Reduction Device>

[0491] A carbon dioxide reduction device was obtained by the same procedure as in Example 1, except that the carbon dioxide reduction electrode of Example 12 was used instead of the carbon dioxide reduction electrode of Example 1.

[0492] <Manufacturing of Ethylene>

[0493] Ethylene was synthesized by the same procedure as in Example 2, except that the carbon dioxide reduction apparatus of Example 12 was used instead of the carbon dioxide reduction apparatus of Example 1.

[0494] <<Example 13>>

[0495] (Synthesis of Oxygen-bridged Binuclear Copper Complex 12)

[0496] Using compound 17 synthesized by the method described in Tetrahedron, 1999, 55, 8377, an oxy-bridged binuclear copper complex 12 (ie, carbon dioxide reduction catalyst 12) was synthesized according to the reaction formula shown below.

[0497] [Chemical Formula 60]

[0498]

[0499] After the reaction vessel was filled with nitrogen atmosphere, 5.0 mL of pre-degassed methanol was added to 0.08 g (0.38 mmol) of copper acetate monohydrate and the mixture was suspended. 5.0 mL of chloroform was added thereto and the temperature was raised to 50°C to prepare a copper acetate solution. After another reaction vessel was filled with nitrogen atmosphere, a suspension containing 0.1 g (0.19 mmol) of compound 17, 0.03 g (0.19 mmol) of 4-tert-butylbenzene-1,2-diamine, and 10 mL of chloroform was prepared. This suspension was added dropwise to the copper acetate solution, the temperature was raised to 65°C, and the mixture was stirred for 3 hours while refluxed to obtain a reaction solution containing the oxygen-bridged binuclear copper complex 11. After the reaction solution was cooled to room temperature, the solvent was distilled off. The obtained solid was washed with acetone and filtered, and then dried under reduced pressure to obtain the oxygen-bridged binuclear copper complex 12 with a yield of 0.15 g and a yield of 89%. The identification data of the obtained oxygen-bridged binuclear copper complex 12 (carbon dioxide reduction catalyst 12) are shown below. The results of ESI-MS measurement were confirmed as follows.

[0500] ESI-MS[M+H] + :m / z=903.3

[0501] The distance between copper atoms in oxygen-bridged binuclear copper complex 12 is

[0502] <Fabrication of Carbon Dioxide Reduction Electrode>

[0503] The carbon dioxide reduction electrode of Example 12 was obtained by the same procedure as in Example 1 except that the oxygen-bridged binuclear copper complex 12 was used instead of the oxygen-bridged binuclear copper complex 1.

[0504] <Fabrication of Carbon Dioxide Reduction Device>

[0505] A carbon dioxide reduction device was obtained by the same procedure as in Example 1, except that the carbon dioxide reduction electrode of Example 12 was used instead of the carbon dioxide reduction electrode of Example 1.

[0506] <Manufacturing of Ethylene>

[0507] Ethylene was synthesized by the same procedure as in Example 2, except that the carbon dioxide reduction apparatus of Example 12 was used instead of the carbon dioxide reduction apparatus of Example 1.

[0508] <<Example 14>>

[0509] (Synthesis of Compound 20)

[0510] Compound 20 was synthesized using compound 19 synthesized by the method described in International Publication No. 2017-073467 according to the reaction formula shown below.

[0511] [Chemical Formula 61]

[0512]

[0513] After the reaction vessel is filled with nitrogen atmosphere, 28 mL of pre-degassed DMSO is added to 2.5 g (5.2 mmol) of compound 19 to dissolve it. 5.2 g (26.0 mmol) of dodecanethiol and 6.0 g (31.2 mmol) of sodium methoxide methanol solution are added thereto, the temperature is raised to 80 ° C, and the mixture is stirred for 8 hours. After the reaction solution is allowed to cool to room temperature, the reaction solution is neutralized with 1 M hydrochloric acid and extracted with chloroform. The organic layer is dehydrated with magnesium sulfate and concentrated with a rotary evaporator to remove the solvent by distillation. N-heptane is added to the crude product obtained, and the precipitated solid is obtained by filtration while washing with n-heptane and drying under reduced pressure to obtain compound 20 with a yield of 1.0 g and a yield of 42%. The identification data of the obtained compound 20 are shown below. The results of the 1H NMR determination were confirmed as follows.

[0514] 1H NMR (CDCl3, 400MHz): 13.86 (s, 2H), 8.09 (m, 6H), 7.90 (d, 2H), 7.42 (dd, 2H), 6.99 (d, 2H), 1, 39 (s, 18H)

[0515] (Synthesis of Compound 21)

[0516] Compound 21 was synthesized according to the reaction formula shown below.

[0517] [Chemical Formula 62]

[0518]

[0519] After the reaction vessel is in a nitrogen atmosphere, 0.6 g (1.3 mmol) of compound 20, 0.45 g (3.18 mmol) of hexamethylenetetramine (HMTA), and 6.6 mL of trifluoroacetic acid (TFA) are added, and the temperature is raised to 100 ° C while stirring, and the mixture is kept warm for 8 hours. After the reaction solution is cooled to 60 ° C, 20 mL of 30% sulfuric acid aqueous solution and 20 mL of chloroform are added, and the mixture is stirred for 1 hour in a warm state. The organic layer is separated by liquid separation, dehydrated with magnesium sulfate, and concentrated with a rotary evaporator, thereby distilling off the solvent. Methanol is added to the crude product obtained, and the precipitated solid is obtained by filtration while washing with methanol, and dried under reduced pressure to obtain compound 21 with a yield of 0.32 g and a yield of 47%. The identification data of the obtained compound 21 are shown below. The results of the 1H NMR measurement were confirmed as follows.

[0520] 1H NMR (CDCl3, 400MHz): 10.46 (s, 2H), 8.13 (m, 6H), 8.02 (m, 2H), 7.83 (d, 2H), 1, 31 (s, 18H)

[0521] (Synthesis of Oxygen-bridged Binuclear Copper Complex 13)

[0522] Using compound 21, an oxy-bridged binuclear copper complex 13 (ie, carbon dioxide reduction catalyst 13) was synthesized according to the reaction formula shown below.

[0523] [Chemical Formula 63]

[0524]

[0525] After the reaction vessel is filled with nitrogen atmosphere, 5.0 mL of pre-degassed methanol is added to 0.08 g (0.39 mmol) of copper acetate monohydrate to suspend it. 5.0 mL of chloroform is added thereto and the temperature is raised to 50°C to prepare a copper acetate solution. After another reaction vessel is filled with nitrogen atmosphere, a suspension containing 0.1 g (0.197 mmol) of compound 21, 0.02 g (0.197 mmol) of 1,2-phenylenediamine and 10 mL of chloroform is prepared. After the suspension is added dropwise to the above copper acetate solution, the temperature is raised to 65°C and stirred for 3 hours while reflux to obtain a reaction solution containing oxygen-bridged binuclear copper complex 12. After the reaction solution is cooled to room temperature, the solvent is distilled off. The obtained solid is obtained by filtration while washing with acetone and dried under reduced pressure to obtain oxygen-bridged binuclear copper complex 13 with a yield of 0.14 g and a yield of 84%. The identification data of the obtained oxygen-bridged binuclear copper complex 13 (carbon dioxide reduction catalyst 13) are shown below. The results of ESI-MS measurement were confirmed as follows.

[0526] ESI-MS[M-OAc] + :m / z=765.2

[0527] The distance between copper atoms in oxygen-bridged binuclear copper complex 13 is

[0528] <Fabrication of Carbon Dioxide Reduction Electrode>

[0529] The carbon dioxide reduction electrode of Example 14 was obtained by the same procedure as in Example 1 except that the oxygen-bridged binuclear copper complex 13 was used instead of the oxygen-bridged binuclear copper complex 1.

[0530] <Fabrication of Carbon Dioxide Reduction Device>

[0531] A carbon dioxide reduction device was obtained by the same procedure as in Example 1, except that the carbon dioxide reduction electrode of Example 14 was used instead of the carbon dioxide reduction electrode of Example 1.

[0532] <Manufacturing of Ethylene>

[0533] Ethylene was synthesized by the same procedure as in Example 2, except that the carbon dioxide reduction apparatus of Example 14 was used instead of the carbon dioxide reduction apparatus of Example 1.

[0534] <Fabrication of Carbon Dioxide Reduction Electrode>

[0535] The carbon dioxide reduction electrode of Example 14 was obtained by the same procedure as in Example 1 except that the oxygen-bridged binuclear copper complex 13 was used instead of the oxygen-bridged binuclear copper complex 1.

[0536] <Fabrication of Carbon Dioxide Reduction Device>

[0537] A carbon dioxide reduction device was obtained by the same procedure as in Example 1, except that the carbon dioxide reduction electrode of Example 14 was used instead of the carbon dioxide reduction electrode of Example 1.

[0538] <Manufacturing of Ethylene>

[0539] Ethylene was synthesized by the same procedure as in Example 2, except that the carbon dioxide reduction apparatus of Example 14 was used instead of the carbon dioxide reduction apparatus of Example 1.

[0540] <<Example 15>>

[0541] (Synthesis of Compound 22)

[0542] Compound 22 was synthesized according to the reaction formula shown below.

[0543] [Chemical Formula 64]

[0544]

[0545] Under a nitrogen atmosphere, 37 ml of dehydrated toluene and 264 mg (0.33 mmol) of N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate were added, and the resulting solution was heated to 80°C while stirring with a stirrer. To this solution was added dropwise a mixture of 0.60 g (3.63 mmol) of aldehyde, 2.0 g (3.30 mmol) of compound 6, and 5 ml of toluene. After stirring for 3 hours, the reaction mixture was allowed to cool gradually to room temperature.

[0546] To the reaction solution, a solution prepared by dissolving 0.39 g (3.63 mmol) of benzoquinone in 5 ml of THF was added dropwise. After confirming the completion of the reaction, the resulting reaction solution was filtered to obtain the target compound 23 with a yield of 2.27 g and a yield of 91%. The identification data of the resulting compound 22 are shown below. The results of the ESI-MS measurement were confirmed as follows.

[0547] ESI-MS[M+H] + :m / z=753.3

[0548] (Synthesis of Oxygen-bridged Binuclear Copper Complex 14)

[0549] According to the reaction formula shown below, the oxygen-bridged binuclear copper complex 14 (ie, the carbon dioxide reduction catalyst 14) is synthesized.

[0550] [Chemical Formula 65]

[0551]

[0552] After the reaction vessel is in a nitrogen atmosphere, 6 mL of pre-degassed methanol is added to 0.29 g (1.46 mmol) of copper acetate monohydrate to suspend it. 6 mL of chloroform is added thereto, the temperature is raised to 50 ° C, and a copper acetate solution is prepared. After another reaction vessel is in a nitrogen atmosphere, a suspension containing 0.5 g (0.66 mmol) of compound 23 and 10 mL of chloroform is prepared. After the suspension is added dropwise to the above-mentioned copper acetate solution, the temperature is raised to 55 ° C, and the mixture is stirred for 1 hour while refluxing to obtain a reaction solution containing an oxygen-bridged binuclear copper complex 5. After the reaction solution is cooled to room temperature, it is filtered. The obtained crystals are dried under reduced pressure to obtain an oxygen-bridged binuclear copper complex 14 with a yield of 0.4 g and a yield of 64%. The identification data of the obtained oxygen-bridged binuclear copper complex 14 (carbon dioxide reduction catalyst 14) are shown below. The results of the ESI-MS determination were confirmed as follows.

[0553] ESI-MS[M-OAc] + :m / z=875.2

[0554] The distance between copper atoms in oxygen-bridged binuclear copper complex 14 is

[0555] <Fabrication of Carbon Dioxide Reduction Electrode>

[0556] The carbon dioxide reduction electrode of Example 15 was obtained by the same procedure as in Example 1 except that the oxygen-bridged binuclear copper complex 14 was used instead of the oxygen-bridged binuclear copper complex 1.

[0557] <Fabrication of Carbon Dioxide Reduction Device>

[0558] A carbon dioxide reduction device was obtained by the same procedure as in Example 1, except that the carbon dioxide reduction electrode of Example 15 was used instead of the carbon dioxide reduction electrode of Example 1.

[0559] <Manufacturing of Ethylene>

[0560] Ethylene was synthesized by the same procedure as in Example 2, except that the carbon dioxide reduction apparatus of Example 15 was used instead of the carbon dioxide reduction apparatus of Example 1.

[0561] <<Example 16>>

[0562] (Synthesis of Compound 23)

[0563] Compound 23 was synthesized according to the reaction formula shown below.

[0564] [Chemical Formula 66]

[0565]

[0566] Under a nitrogen atmosphere, 10 ml of dehydrated chloroform and 66 mg (0.08 mmol) of N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate were added, and the resulting solution was heated to 80°C while stirring with a stirrer. To this solution was added dropwise a mixture of 0.09 g (0.37 mmol) of aldehyde, 0.5 g (0.82 mmol) of compound 6, and 12 ml of chloroform. After stirring for 3 hours, the reaction mixture was allowed to cool gradually to room temperature.

[0567] A solution prepared by dissolving 0.1 g (0.906 mmol) of benzoquinone in 1 ml of THF was added dropwise to the reaction solution. After confirming the completion of the reaction, the resulting reaction solution was filtered to obtain the target compound 23 with a yield of 0.51 g and a yield of 99%. The identification data of the obtained compound 23 are shown below. The results of the ESI-MS measurement were confirmed as follows.

[0568] ESI-MS[M+H] + :m / z=1407.2

[0569] (Synthesis of Oxygen-bridged Tetranuclear Copper Complex 1)

[0570] According to the reaction formula shown below, the oxy-bridged tetranuclear copper complex 1 (ie, the carbon dioxide reduction catalyst 15) was synthesized.

[0571] [Chemical Formula 67]

[0572]

[0573] After the reaction vessel is filled with nitrogen atmosphere, 5 mL of pre-degassed dimethylformamide is added to 0.2 g (0.142 mmol) of compound 23 and 0.13 g (0.64 mmol) of copper acetate monohydrate, the temperature is raised to 100 ° C, and the mixture is stirred for 3 hours. The reaction solution is then heated to 130 ° C and stirred for 6 hours. After the reaction solution is cooled to room temperature, chloroform and water are added for liquid separation. The organic layer is dried over sodium sulfate and filtered, and heptane is added to the filtrate to precipitate the oxygen-bridged tetranuclear copper complex 1, which is filtered and taken out. It is obtained in an amount of 0.25 g and a yield of 99%. The identification data of the obtained oxygen-bridged tetranuclear copper complex 1 (carbon dioxide reduction catalyst 15) are shown below. The results of the ESI-MS determination were confirmed as follows.

[0574] ESI-MS[M-OAc] + :m / z=1654.3

[0575] The distance between copper atoms in oxygen-bridged tetranuclear copper complex 1 is and

[0576] <Fabrication of Carbon Dioxide Reduction Electrode>

[0577] The carbon dioxide reduction electrode of Example 16 was obtained by the same procedure as in Example 1 except that the oxygen-bridged tetranuclear copper complex 1 was used instead of the oxygen-bridged binuclear copper complex 1.

[0578] <Fabrication of Carbon Dioxide Reduction Device>

[0579] A carbon dioxide reduction device was obtained by the same procedure as in Example 1, except that the carbon dioxide reduction electrode of Example 16 was used instead of the carbon dioxide reduction electrode of Example 1.

[0580] <Manufacturing of Ethylene>

[0581] Ethylene was synthesized by the same procedure as in Example 2, except that the carbon dioxide reduction apparatus of Example 16 was used instead of the carbon dioxide reduction apparatus of Example 1.

[0582] <<Comparative Example 1>>

[0583] <Synthesis of Carbon Dioxide Reduction Catalyst>

[0584] The halogen-bridged binuclear copper complex 1 was synthesized according to the reaction formula shown below using the method described in Japanese Patent Application Laid-Open No. 2021-109157. In the following reaction formula, "Ph" means a phenyl group.

[0585] [Chemical Formula 68]

[0586]

[0587] <Fabrication of Carbon Dioxide Reduction Electrode>

[0588] 105.12 mg (0.079 mmol) of halogen-bridged binuclear copper complex 1 was weighed into a reaction vessel, 52 mL of H₂O and 33 mL of methanol were added, and a dispersion was prepared by repeated stirring and ultrasonic irradiation. In another reaction vessel, 200 mg of carbon black (KetjenBlack EC600JD, manufactured by Lion Specialty Chemicals Co., Ltd.) was weighed as a conductive material, and the above dispersion was added dropwise to obtain a new dispersion. The dispersion was irradiated with ultrasonic waves for 15 minutes to uniformly disperse the conductive material loaded with the carbon dioxide reduction catalyst, resulting in a suspension having a copper atom content of 5% by mass relative to the mass of the carbon black. The carbon dioxide reduction electrode of Comparative Example 1 was obtained using the same procedures as in Example 1 for subsequent operations.

[0589] The interatomic distance between copper atoms in the halogen-bridged binuclear copper complex 1 is

[0590] <Fabrication of Carbon Dioxide Reduction Device>

[0591] A carbon dioxide reduction device was obtained by the same procedure as in Example 1, except that the carbon dioxide reduction electrode of Comparative Example 1 was used instead of the carbon dioxide reduction electrode of Example 1.

[0592] <Manufacturing of Ethylene>

[0593] Ethylene was synthesized by the same procedure as in Example 1, except that the carbon dioxide reduction apparatus of Comparative Example 1 was used instead of the carbon dioxide reduction apparatus of Example 1.

[0594] <<Comparative Example 2>>

[0595] <Preparation of Carbon Dioxide Reduction Catalyst>

[0596] As a carbon dioxide reduction catalyst in Comparative Example 2, 212.83 mg (0.3147 mmmol) of tetraphenylporphyrin copper (produced by Tokyo Chemical Industry Co., Ltd.) was prepared.

[0597] <Fabrication of Carbon Dioxide Reduction Electrode>

[0598] A carbon dioxide reduction electrode of Comparative Example 2 was obtained by the same procedure as in Example 1 except that tetraphenylporphyrin copper was used instead of the oxygen-bridged binuclear copper complex 1.

[0599] <Fabrication of Carbon Dioxide Reduction Device>

[0600] A carbon dioxide reduction device was obtained by the same procedure as in Example 1, except that the carbon dioxide reduction electrode of Comparative Example 2 was used instead of the carbon dioxide reduction electrode of Example 1.

[0601] <Manufacturing of Ethylene>

[0602] Ethylene was synthesized by the same procedure as in Example 1, except that the carbon dioxide reduction apparatus of Comparative Example 2 was used instead of the carbon dioxide reduction apparatus of Example 1.

[0603] <<Comparative Example 3>>

[0604] <Manufacturing of Ethylene>

[0605] Ethylene was synthesized by the same procedure as in Example 2, except that the carbon dioxide reduction apparatus of Comparative Example 1 was used instead of the carbon dioxide reduction apparatus of Example 1.

[0606] <<Comparative Example 4>>

[0607] <Manufacturing of Ethylene>

[0608] Ethylene was synthesized by the same procedure as in Example 2, except that the carbon dioxide reduction apparatus of Comparative Example 2 was used instead of the carbon dioxide reduction apparatus of Example 1.

[0609] <<Evaluation>>

[0610] <Calculation of distance between copper atoms>

[0611] The distance between copper atoms was calculated according to the method described in the aforementioned “· Calculation method of the distance between copper atoms”.

[0612] It should be noted that copper tetraphenylporphyrin is a mononuclear copper complex, so the distance between copper atoms is not calculated.

[0613] Here, oxygen-bridged binuclear copper complexes 1-7 and 14 have acetate anions as counteranions during synthesis. However, during the carbon dioxide reduction reaction, the copper centers are each reduced to a valence of 1, and it is believed that the acetate anions are separated and the copper atoms are in a monoanionic state. Therefore, for oxygen-bridged binuclear copper complexes 1-7 and 14, the interatomic distances between copper atoms in the monoanionic state were calculated.

[0614] Furthermore, the oxygen-bridged binuclear copper complex 8 has two chloride anions as counter anions during synthesis. However, during the carbon dioxide reduction reaction, each copper center is reduced to a valence of 1, which is considered to be a neutral state after the chloride anions are removed. Therefore, for the oxygen-bridged binuclear copper complex 8, the distance between copper atoms in the neutral state was calculated.

[0615] Furthermore, oxygen-bridged binuclear copper complexes 10-13 have two acetate anions as counter anions during synthesis. During the carbon dioxide reduction reaction, the copper centers are each reduced to a valence of 1, which is considered to be a neutral state after the acetate anions are removed. Therefore, for oxygen-bridged binuclear copper complexes 10-13, the interatomic distances between copper atoms in the neutral state were calculated.

[0616] Furthermore, the oxygen-bridged tetranuclear copper complex 1 has two acetate anions as counter anions during synthesis. However, during the carbon dioxide reduction reaction, each copper center is reduced to a valence of 1, which is considered to be a dianionic state after the acetate anions are separated. Therefore, for the oxygen-bridged tetranuclear copper complex 1, the interatomic distances between copper atoms in the dianionic state were calculated.

[0617] In addition, each copper center of the halogen-bridged binuclear copper complex 1 has a valence of 1 and is considered to be in a neutral state. Therefore, the distance between copper atoms in the neutral state of the halogen-bridged binuclear copper complex 1 was calculated.

[0618] <Ethylene Selectivity Evaluation>

[0619] Using the carbon dioxide reduction apparatus obtained in each example, ethylene selectivity was evaluated by the following procedure.

[0620] From 100 to 200 seconds after the start of voltage application, 50 μL of outlet gas (gas flowing out of the reaction tank 16 in the direction of arrow B) was collected using a gas-tight syringe, and the products contained in the gas were quantitatively analyzed using a gas chromatograph (Shimadzu GC-2010 / FID detector and Shimadzu GC-2014 / TCD detector). The Faraday efficiency of each product was calculated by the ratio of the amount of charge used in the generation of each product to the total amount of charge used in the reaction. The current flowing through the reaction area of ​​the carbon dioxide reduction electrode 10 was expressed as mA / cm per unit area. 2 ) is converted into a current value.

[0621] The conversion from the Ag / AgCl reference potential to the RHE reference potential is performed based on the following equation.

[0622] Formula: E(RHE)=E(Ag / AgCl)+0.198V+0.059×pH

[0623] A higher value of the Faradaic efficiency of ethylene indicates more selective production of ethylene, which means higher ethylene selectivity.

[0624] [Table 1]

[0625]

[0626] According to the above results, the ethylene production method of this embodiment has higher ethylene selectivity than that of the comparative example.

[0627] Description of Reference Numerals

[0628] 1 includes a layer of a conductive material carrying a carbon dioxide reduction catalyst, 2 a support, 10 a carbon dioxide reduction electrode, 11 an oxidation electrode, 12 a membrane, 13 an electrolyte, 14 a power source, 15 an electrolytic cell, 16 a reaction cell, and 100 a carbon dioxide reduction device.

Claims

1. A method for producing ethylene, comprising reacting carbon dioxide with water in the presence of a carbon dioxide reduction catalyst, wherein the carbon dioxide reduction catalyst is a polynuclear copper complex and the interatomic distance between copper atoms obtained by density functional theory is the following.

2. The method for producing ethylene according to claim 1, wherein The carbon dioxide reduction catalyst is a multinuclear copper complex in which a copper atom is coordinated and bonded with two oxygen atoms.

3. A method for producing ethylene, comprising reacting carbon dioxide with water in the presence of a carbon dioxide reduction catalyst represented by the following formula (1). [Chemical Formula 1] In the above formula (1), R 1 Represents a hydrogen atom or a substituent, and there are multiple R 1 Each can be the same or different; two adjacent R 1 Can bond with each other to form a ring; P 1 represents a divalent group containing one or more aromatic rings; Q 1 and Q 2 represents a monovalent group containing one or more aromatic rings, Q 1 With Q 2 They can bond to each other to form a ring structure; a is an integer from 2 to 4; X is a counter ion or a neutral molecule, b is an integer from 0 to 0, and when there are multiple Xs, each of them can be the same or different; O is an oxygen atom, bonded to at least one copper atom.

4. The method for producing ethylene according to claim 3, wherein: The P 1 The following formula (P a ) or the following formula (P b ), [Chemical Formula 2] The above formula (P a ), R 2 and R 3 Each independently represents a hydrogen atom or a substituent, and two adjacent R 2 Each other and the two adjacent R 3 They can be bonded to each other to form a ring structure; the above formula (P b ), R 4 and R 5 represents a hydrogen atom or a substituent, two adjacent R 4 Each other, and adjacent R 4 With R 5 Can bond with each other to form a ring structure; there are multiple R 4 They may be the same or different; it should be noted that * represents a connecting bond.

5. The method for producing ethylene according to claim 3, wherein: The carbon dioxide reduction catalyst is a compound represented by the following formula (2): [Chemical Formula 3] In the above formula (2), R 6 ~R 8 Each independently represents a hydrogen atom or a substituent, and two adjacent R 6 Two adjacent Rs 7 Each other, and the two adjacent R 8 They can bond with each other to form a ring structure; there are multiple R 6 ~R 8 Each can be the same or different; Q 3 and Q 4 represents a monovalent group containing one or more aromatic rings, Q 3 With Q 4 They can bond to each other to form a ring structure; a is an integer from 2 to 4; X is a counter ion or a neutral molecule, b is an integer from 0 to 0, and when there are multiple Xs, each of them can be the same or different; O is an oxygen atom, bonded to at least one copper atom.

6. The method for producing ethylene according to claim 3, wherein: The carbon dioxide reduction catalyst is a compound represented by the following formula (3): [Chemical Formula 4] In the above formula (3), R 9 ~R 13 Each independently represents a hydrogen atom, a substituent or a divalent group, and two adjacent R 9 Two adjacent Rs 10 Two adjacent Rs 11 Two adjacent Rs 12 Each other, and adjacent R 12 With R 13 Can bond with each other to form a ring structure; there are multiple R 9 ~R 12 Each can be the same or different; R 13 When it is a divalent group, the divalent group can form a bond with another compound represented by the above formula (3) to form a dimer; X is a counterion or a neutral molecule, b is an integer greater than 0, and when there are multiple Xs, each of them may be the same or different.

7. The method for producing ethylene according to claim 3, wherein: The carbon dioxide reduction catalyst is a compound represented by the following formula (4): [Chemical Formula 5] In the above formula (4), R 14 ~R 16 Each independently represents a hydrogen atom or a substituent, and two adjacent R 14 Two adjacent Rs 15 Each other, and adjacent R 15 With R 16 Can be connected to form a ring; there are multiple R 14 ~R 16 Each may be the same or different; X is a counter ion or a neutral molecule, b is an integer greater than or equal to 0, and when there are multiple Xs, each may be the same or different.

8. The method for producing ethylene according to claim 3, wherein: The carbon dioxide reduction catalyst is a compound represented by the following formula (5): [Chemical Formula 6] In the above formula (5), R 17 ~R 21 Each independently represents a hydrogen atom or a substituent, and two adjacent R 17 Two adjacent Rs 18 Two adjacent Rs 19 Two adjacent Rs 20 Each other, and the two adjacent R 21 They can be connected to each other to form a ring; there are multiple R 17 ~R 21 Each may be the same or different; X is a counter ion or a neutral molecule, b is an integer greater than or equal to 0, and when there are multiple Xs, each may be the same or different.

9. The method for producing ethylene according to claim 3, wherein: The carbon dioxide reduction catalyst is a compound represented by the following formula (6): [Chemical Formula 7] In formula (6), R 22 ~R 26 Each independently represents a hydrogen atom or a substituent, and two adjacent R 22 Two adjacent Rs 23 Two adjacent Rs 24 Two adjacent Rs 26 Each other, and adjacent R 25 With R 26 Can bond with each other to form a ring structure; there are multiple R 22 ~R 26 Each may be the same or different; X is a counter ion or a neutral molecule, b is an integer greater than or equal to 0, and when there are multiple Xs, each may be the same or different.

10. The method for producing ethylene according to claim 3, wherein: The carbon dioxide reduction catalyst is a compound represented by the following formula (7): [Chemical Formula 8] In the above formula (7), R 27 ~R 34 Each independently represents a hydrogen atom or a substituent, and two adjacent R 27 Two adjacent Rs 28 Two adjacent Rs 29 Two adjacent Rs 30 Two adjacent Rs 31 Two adjacent Rs 32 Two adjacent Rs 33 Each other, and the two adjacent R 34 They can bond with each other to form a ring structure; there are multiple R 27 ~R 34 Each may be the same or different; Ar represents a divalent aromatic group which may have a substituent; a is an integer of 2 or more and 4 or less; X is a counter ion or a neutral molecule, b is an integer of 0 or more, and when there are multiple Xs, each may be the same or different; O is an oxygen atom bonded to at least one copper atom.

11. A carbon dioxide reduction electrode comprising a multinuclear copper complex and wherein the distance between copper atoms calculated by density functional theory is The following carbon dioxide reduction catalyst, or a conductive material of a carbon dioxide reduction catalyst represented by the following formula (1), [Chemical Formula 9] In the above formula (1), R 1 Represents a hydrogen atom or a substituent, and there are multiple R 1 Each can be the same or different; two adjacent R 1 Can bond with each other to form a ring; P 1 represents a divalent group containing one or more aromatic rings; Q 1 and Q 2 represents a monovalent group containing one or more aromatic rings, Q 1 With Q 2 They can bond to each other to form a ring structure; a is an integer from 2 to 4; X is a counter ion or a neutral molecule, b is an integer from 0 to 0, and when there are multiple Xs, each of them can be the same or different; O is an oxygen atom, bonded to at least one copper atom. 12 . The carbon dioxide reduction electrode according to claim 11 , further comprising a support for supporting the conductive material.

13. The carbon dioxide reduction electrode according to claim 11 or 12, comprising an ion conductor.

14. A carbon dioxide reduction device comprising: Oxidation electrode; The carbon dioxide reduction electrode according to claim 11; a membrane separating the oxidation electrode from the carbon dioxide reduction electrode; electrolyte; and A power source connected to the oxidation electrode and the carbon dioxide reduction electrode.

Images