Fluorine-containing compounds having sulfonic acid groups and polymer electrolyte fuel cells

Abstract

The present invention provides a compound which exhibits good solubility in a polar solvent, while enabling a polymer electrolyte fuel cell to have good power generation characteristics if used as an electrolyte in a catalyst layer of the polymer electrolyte fuel cell.　A compound which has a structure represented by general formula (I). (In general formula (I), Ar1 represents an aromatic structure that is optionally substituted by a sulfonic acid group; Ar2 represents an aromatic structure that is optionally substituted by a sulfonic acid group; A3 represents an aromatic structure that is optionally substituted by a sulfonic acid group; when p = 1, Ar2 represents a benzene ring that is optionally substituted by a sulfonic acid group; each of R1 to R5 independently represents a hydrogen atom, a sulfonic acid group or an aromatic group, and each aromatic group may be independently substituted by a sulfonic acid group; one of the R1 to R5 moieties represents a hydrogen atom or a sulfonic acid group, while the other four of the moieties represent aromatic groups; one or more moieties selected from the group consisting of Ar1, Ar2, Ar3, benzene ring A, and R1, R2, R3, R4 and R5 in cases where these moieties are aromatic groups have one or more sulfonic acid groups; l and m represent molar fractions in cases where (l + m) = 1.0, and respectively satisfy 0 < l ≤ 1.0 and 0 ≤ m < 1.0; in cases where m is not 0, the constituent units are random copolymerized with each other; each n independently represents an integer of 1 to 3; and p represents 0 or 1.)

Description

[Technical Field]

[0001] The present invention relates to a fluorine-containing compound having a sulfonic acid group and a polymer electrolyte fuel cell using the compound. [Background technology]

[0002] A polymer electrolyte fuel cell (PEFC) has an anode catalyst layer, a cathode catalyst layer, and a solid electrolyte membrane sandwiched between both catalyst layers. Electrolytes used in solid electrolyte membranes require proton conductivity, gas barrier properties, electronic insulation, and durability. Fluorine-based ionomers are used as electrolytes that satisfy these characteristics. As electrolytes used in solid electrolyte membranes and catalyst layers, hydrocarbon ionomers having an aromatic backbone and incorporating sulfone groups into the backbone are known (see, for example, Patent Documents 1 and 2). As compositions used in solid electrolyte membranes, compositions comprising a fluorinated polymer having a sulfone group and a fluorinated aromatic compound having a functional group that can react with the sulfone group of the fluorinated polymer are known (see, for example, Patent Document 3). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] U.S. Patent Publication No. 7301002 [Patent Document 2] Japanese Patent Publication No. 2015-95424 [Patent Document 3] Special table 2014-522437 publication [Overview of the project] [Problems that the invention aims to solve]

[0004] The catalyst layer is manufactured by coating a catalyst composition, in which a catalyst, catalyst support, and electrolyte are dispersed or dissolved in a solvent, onto a solid electrolyte membrane and a substrate. Polar solvents such as alcohol and water are commonly used as solvents. On the other hand, the electrolyte in the catalyst layer requires not only proton conductivity but also gas permeability and electron conductivity. Therefore, if the electrolyte covers at least a portion of the catalyst supported on the catalyst support, these properties are more likely to be exhibited, and polymer electrolyte fuel cells can obtain good power generation characteristics. To achieve this, it is desirable that at least a portion of the electrolyte in the catalyst composition is dissolved in the solvent, and that the proportion of dissolution is high. However, in the composition described in Patent Document 3, since its application is as a solid electrolyte, the issue of catalyst coating is not addressed, and the solubility in solvents of the compound formed by the reaction of the fluorinated polymer and the reactive fluorinated aromatic compound was not investigated.

[0005] The present invention aims to provide a compound that exhibits good solubility in polar solvents and, when used as an electrolyte in the catalyst layer of a polymer electrolyte fuel cell, enables the polymer electrolyte fuel cell to achieve good power generation characteristics. [Means for solving the problem]

[0006] The present invention includes, for example, the following [1] to

[13] . [1] A compound having a structure represented by the following general formula (I). [ka] (In general formula (I), Ar 1 It has an aromatic structure, and is sometimes substituted with a sulfonic acid group. Ar 2 It has an aromatic structure, and is sometimes substituted with a sulfonic acid group. Ar 3 It has an aromatic structure, and is sometimes substituted with a sulfonic acid group. However, when p=1, Ar 2 It is a benzene ring, which is sometimes substituted with a sulfonic acid group. R1 ~R 5 is, independently of one another, hydrogen, a sulfonic acid group or an aromatic group, and the aromatic groups are, independently of one another, optionally substituted with sulfonic acid groups, R 1 ~R 5 one of ~R is hydrogen or a sulfonic acid group, and four are aromatic groups, Ar 1 、Ar 2 、Ar 3 、R when it is an aromatic group 1 、R 2 、R 3 、R 4 and R 5 and at least one selected from the group consisting of benzene ring A has one or more sulfonic acid groups, l and m are mole fractions when l + m = 1.0, where 0 < l ≤ 1.0 and 0 ≤ m < 1.0, and when m is not 0, each structural unit is randomly copolymerized, n is, independently of one another, an integer from 1 to 3, p is 0 or 1.) [2] A compound obtained by reacting a compound represented by the following general formula (pre-I) with a sulfonating agent. [Chemical formula] (In the general formula (pre-I), Ar 1 ’ is an aromatic structure, Ar 2 ’ is an aromatic structure, Ar 3 ’ is an aromatic structure, however, when p = 1, Ar 2 ’ is a benzene ring, R 1 ’~R 5 ’ are, independently of one another, hydrogen or an aromatic group, R 1 ’~R 5 ’ one of which is hydrogen, and four are aromatic groups, l and m are mole fractions when l + m = 1.0, where 0 < l ≤ 1.0 and 0 ≤ m < 1.0. When m is not 0, each structural unit is randomly copolymerized. n is, independently of each other, an integer of 1 to 3. p is 0 or 1. ) [3] In the general formula (I), Ar 1 is [Chemical formula] selected from the group consisting of (where X is, independently of each other, hydrogen, an alkyl group having 1 to 8 carbon atoms or a phenyl group), and is optionally substituted with a sulfonic acid group, a compound of [1]. [4] In the general formula (I), when it is aromatic, R 1 ~R 5 are, independently of each other [Chemical formula] selected from the group consisting of, and is optionally substituted with a sulfonic acid group, a compound of [1]. [5] In the general formula (pre-I), Ar 1 ’ is [Chemical formula] selected from the group consisting of (where X is, independently of each other, hydrogen, an alkyl group having 1 to 8 carbon atoms or a phenyl group), and is a compound of [2]. [6] In the general formula (pre-I), when it is aromatic, R 1 ’~R 5 ’ are, independently of each other [Chemical formula] selected from the group consisting of, and is a compound of [2]. [7] Any of the compounds [1] to [6] used as the electrolyte for the anode catalyst layer and / or cathode catalyst layer of a polymer electrolyte fuel cell. A catalyst layer for a polymer electrolyte fuel cell containing one of the compounds [8][1] to [6]. A catalyst composition comprising any of the compounds [9][1] to [6], a metal catalyst, and a catalyst support.

[10] A catalyst composition for solid polymer fuel cell [9]. A catalyst layer for a polymer electrolyte fuel cell containing the catalyst composition

[11]

[10] .

[12] A membrane electrode assembly having a solid electrolyte membrane, a gas diffusion layer and

[11] a catalyst layer. A polymer electrolyte fuel cell having a membrane electrode assembly

[13]

[12] . [Effects of the Invention]

[0007] The compound of the present invention exhibits good solubility in polar solvents, and when used as an electrolyte in the catalyst layer of a polymer electrolyte fuel cell, the polymer electrolyte fuel cell exhibits excellent power generation characteristics. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic cross-sectional view showing the structure of a polymer electrolyte fuel cell. [Modes for carrying out the invention]

[0009] [First aspect of the present invention] A first aspect of the present invention relates to a compound having a structure represented by the following general formula (I). [ka] (In general formula (I), Ar 1 It has an aromatic structure, and is sometimes substituted with a sulfonic acid group. Ar 2 It has an aromatic structure, and is sometimes substituted with a sulfonic acid group. Ar 3is an aromatic structure, optionally substituted with a sulfonic acid group, however, when p = 1, Ar 2 is a benzene ring, optionally substituted with a sulfonic acid group, R 1 ~R 5 are each independently hydrogen, a sulfonic acid group or an aromatic group, and the aromatic groups are each independently optionally substituted with a sulfonic acid group, R 1 ~R 5 one of them is hydrogen or a sulfonic acid group, and four are aromatic groups, Ar 1 Ar 2 Ar 3 when it is an aromatic group, R 1 R 2 R 3 R 4 and R 5 and the benzene ring A, one or more selected from the group consisting of have one or more sulfonic acid groups, l and m are mole fractions when l + m = 1.0, where 0 < l ≤ 1.0 and 0 ≤ m < 1.0. When m is not 0, each structural unit is randomly copolymerized, n is each independently an integer from 1 to 3, p is 0 or 1.)

[0010] Ar in the general formula (I) 1 Ar 2 Ar 3 R 1 R 2 R 3 R 4 R 5 l, m, n and p are as follows. Ar 1 is an aromatic structure, optionally substituted with a sulfonic acid group. Ar 1 preferably has no substituent other than the sulfonic acid group. Examples of the aromatic structure include monocyclic aromatics, polycyclic aromatics, condensed aromatic rings and aromatic heterocycles, with monocyclic aromatics and polycyclic aromatics being preferred. Ar1 is one selected from the group consisting of the following (wherein X is independently hydrogen, an alkyl group having 1 to 8 carbon atoms, or a phenyl group), and is more preferably substituted with a sulfonic acid group. [ka] One selected from the group consisting of the following, and more preferably, substituted with a sulfonic acid group. [ka]

[0011] Ar 2 It has an aromatic structure and may be substituted with a sulfonic acid group. 2 It is preferable that it does not have substituents other than the sulfonic acid group. Aromatic structures include monocyclic aromatics, polycyclic aromatics, fused aromatic rings, and aromatic heterocycles, with monocyclic aromatics and aromatic heterocycles being preferred, and benzene rings being more preferred. Aromatic heterocycles are cyclic compounds that contain one or more nitrogen atoms, sulfur atoms, and oxygen atoms in addition to carbon atoms. Examples of aromatic heterocycles containing nitrogen include pyridine, pyrazine, pyrimidine, pyridazine, quinoline, and isoquinoline. Examples of aromatic heterocycles containing sulfur include thiophene and bensothiophene. Examples of aromatic heterocycles containing oxygen include furan and benzofuran. When p=1, Ar 2 This is a benzene ring, which may be substituted with a sulfonic acid group.

[0012] Ar 3 It has an aromatic structure and may be substituted with a sulfonic acid group. 3 It is preferable that it does not have substituents other than the sulfonic acid group. As for aromatic structures, Ar 2 Examples similar to those exemplified above can be given.

[0013] R1 ~R 5 Each of these is independently a hydrogen atom, a sulfonic acid group, or an aromatic group, and R 1 ~R 5 One of these is a hydrogen atom or a sulfonic acid group, and the other four are aromatic groups. Each aromatic group may independently have a sulfonic acid group. It is preferable that the aromatic groups do not have substituents other than sulfonic acid groups. When R is an aromatic group 1 ~R 5 In that sense, each is independent. [ka] One selected from the group consisting of the following, preferably having a sulfonic acid group, [ka] And, in some cases, it is more preferable to have a sulfonic acid group.

[0014] R 1 and R 4 It is preferable that it be the same as R 2 and R 3 It is preferable that they be the same. R 5 It is preferable that it is a hydrogen atom or a sulfonic acid group.

[0015] Ar 1 Ar 2 Ar 3 , when R is an aromatic group 1 , R 2 , R 3 , R 4 and R 5 Furthermore, one or more elements selected from the group consisting of benzene ring A have one or more sulfonic acid groups. When R is an aromatic group 1 , R 2 , R 3 , R 4 and R 5It is preferable that one or more selected from the group consisting of have one or more sulfonic acid groups. The number of sulfonic acid groups in the compound represented by the general formula (I) is preferably 1 to 8, more preferably 1 to 5, and still more preferably 2 to 4.

[0016] l and m are mole fractions when l + m = 1.0, where 0 < l ≤ 1.0 and 0 ≤ m < 1.0, and 0.5 < l ≤ 1.0 and 0 ≤ m < 0.5 are preferred. When m is not 0, the respective structural units that are the mole fractions l and m are randomly copolymerized. n is independently an integer of 1 to 3, and 1 or 2 is preferred. p is 0 or 1, and 0 is preferred.

[0017] As the compound represented by the general formula (I), preferably, a compound represented by the following general formula (Ia) is exemplified.

Chemical formula

[0018] [Method for producing the compound] The compound represented by the general formula (I) is produced by the following production method. In the following production method, Ar 1 ’, Ar 2 ’, Ar 3 ’, R 1 ’, R 2 ’, R 3 ’, R 4 ’ and R 5' is as defined in the general formula (I) unless otherwise specified, that is, as defined in the general formula (pre-I) in the second aspect of the present invention described below. Unless otherwise specified, l, m, n, and p are as defined in the general formula (I).

[0019] (1) Step 1 In Step 1, a bis-halogen monomer having a benzene skeleton with substituents of R' to R' which do not have a sulfonic acid group is produced by the following production method. 1 ’~R 5 ’ having a benzene skeleton with substituents of R' to R' which do not have a sulfonic acid group is produced. In Step 1, a compound represented by the formula (i) and Ar' which is substituted with an ethynyl group and a dihalogen and not substituted with a sulfonic acid group are subjected to a Diels-Alder reaction to obtain a compound represented by the formula (v) which is a bis-halogen monomer. Alternatively, after a compound represented by the formula (i) and Ar' which is substituted with an ethynyl group and a monohalogen and not substituted with a sulfonic acid group are subjected to a Diels-Alder reaction, the halogen group is converted into a boronic acid group or a boronic acid ester group, and then a Suzuki-Miyaura reaction is carried out to obtain a compound represented by the formula (iv) which is a bis-halogen monomer. The reaction temperature is usually 20 to 200 °C. 2 ’ and subjected to a Diels-Alder reaction to obtain a compound represented by the formula (v) which is a bis-halogen monomer. Or a compound represented by the formula (i) and Ar 3 ’ which is substituted with an ethynyl group and a monohalogen and not substituted with a sulfonic acid group are subjected to a Diels-Alder reaction, then the halogen group is converted into a boronic acid group or a boronic acid ester group, and further a Suzuki-Miyaura reaction is carried out to obtain a compound represented by the formula (iv) which is a bis-halogen monomer. The reaction temperature is usually 20 to 200 °C.

Chemical formula

[0020] (2) Step 2 In Step 2, using a palladium catalyst, the reaction of Scheme A or Scheme B is carried out to obtain a fluorine-containing compound represented by the following general formula (pre-I).

Chemical formula

[0021]

Chemical formula

[0022] [ka] However, in Scheme B, Ar in equation (viii) 1’ It is not substituted with a sulfonic acid group. Also, in the general formula (pre-I''), 0 <m’<1.0である。

[0023] The number-average molecular weight (Mn) of the compound represented by general formula (pre-I), as measured by the method described in the examples, is preferably 5,000 to 100,000, more preferably 6,000 to 80,000, and even more preferably 8,000 to 60,000. The molecular weight dispersion (PDI) of the compound represented by general formula (pre-I), as measured by the method described in the examples, is preferably 1 to 8, more preferably 1 to 6, and even more preferably 1 to 4.

[0024] (3) Process 3 In step 3, the compound represented by general formula (pre-I) is reacted with a sulfonating agent to obtain the compound represented by general formula (I), in which a sulfonic acid group is introduced into the compound represented by general formula (pre-I). The sulfonic acid group is the Ar in general formula (pre-I). 1 ', Ar 2 ', Ar 3 ', when R is an aromatic group 1 ', R 2 ', R 3 ', R 4 'and R 5 'and R 1 '~R 5 It is introduced to one or more benzene rings selected from the group consisting of rings having substituents of '. Examples of sulfonating agents include trimethylsilyl chloride sulfate, sulfonic acid chloride, fuming sulfuric acid, and sulfuric acid. It is preferable to react the sulfonating agent in an amount equivalent to 0.5 to 6 times the molecular weight per unit structure, calculated using the mole fraction in the fluorine-containing polymer represented by the general formula (pre-I). Examples of the solvent used in the reaction include halogenated solvents such as methylene chloride and chloroform. The reaction temperature is usually 0 to 100 °C.

[0025] [Second Aspect of the Present Invention] The second aspect of the present invention relates to a compound obtained by reacting a compound represented by the following general formula (pre-I) with a sulfonating agent. [Chemical Formula] (In the general formula (pre-I), Ar 1 ’ is an aromatic structure, Ar 2 ’ is an aromatic structure, Ar 3 ’ is an aromatic structure, However, when p = 1, Ar 2 ’ is a benzene ring, R 1 ’ to R 5 ’ are each independently hydrogen or an aromatic group, R 1 ’ to R 5 ’ one of them is hydrogen, and four are aromatic groups, l and m are mole fractions when l + m = 1.0, where 0 < l ≤ 1.0 and 0 ≤ m < 1.0. When m is not 0, each structural unit is randomly copolymerized, n is each independently an integer from 1 to 3, p is 0 or 1.)

[0026] Ar 1 ’ in the general formula (pre-I), Ar 2 ’ Ar 3 ’ R 1 ’ R 2 ’ R 3 ’ R 4 ’ R 5 ’ l, m, n, and p are as follows. Ar 1 ’ is an aromatic structure. Ar 1It is preferable that the ' does not have substituents. Aromatic structures include monocyclic aromatics, polycyclic aromatics, fused aromatic rings, and aromatic heterocycles, with monocyclic and polycyclic aromatics being preferred.

[0027] Ar 1 ' is more preferably one selected from the group consisting of the following (wherein X is independently hydrogen, an alkyl group having 1 to 8 carbon atoms, or a phenyl group): [ka] It is even more preferable that it be one selected from the group consisting of the following: [ka]

[0028] Ar 2 ' is an aromatic structure. Examples of aromatic structures include monocyclic aromatics, polycyclic aromatics, fused aromatic rings, and aromatic heterocycles, with monocyclic aromatics and aromatic heterocycles being preferred, and benzene rings being more preferred. 2 It is preferable that the ' does not have substituents. Aromatic heterocycles are cyclic compounds that contain one or more nitrogen atoms, sulfur atoms, and oxygen atoms in addition to carbon atoms. Examples of aromatic heterocycles containing nitrogen include pyridine, pyrazine, pyrimidine, pyridazine, quinoline, and isoquinoline. Examples of aromatic heterocycles containing sulfur include thiophene and bensothiophene. Examples of aromatic heterocycles containing oxygen include furan and benzofuran. When p=1, Ar 2 ' is a benzene ring.

[0029] Ar 3 ' is an aromatic structure. As for aromatic structures, Ar 2 Examples similar to those exemplified in ' can be given. 3 It is preferable that the ' does not have substituents.

[0030] R 1 '~R5 ' is each independently hydrogen or an aromatic group, and R 1 ' to R 5 ' in one of which is hydrogen or, and four are aromatic groups. R 1 ' to R 5 ' when it is an aromatic group, it is preferably unsubstituted. R when it is an aromatic group 1 ' to R 5 ' are each independently

Chemical formula

Chemical formula

[0031] R 1 ' and R 4 ' are preferably the same, and R 2 ' and R 3 ' are preferably the same. R 5 ' is preferably hydrogen.

[0032] l and m are mole fractions when l + m = 1.0, where 0 < l ≤ 1.0 and 0 ≤ m < 1.0, and 0.5 < l ≤ 1.0 and 0 ≤ m < 0.5 are preferred. When m is not 0, the respective structural units that are the mole fractions l and m are randomly copolymerized. n is each independently an integer from 1 to 3, and 1 or 2 is preferred. p is 0 or 1, and 0 is preferred.

[0033] The number average molecular weight (Mn) measured by the method described in the examples of the compound represented by the general formula (pre-I) is preferably 5000 to 100000, more preferably 6000 to 80000, and even more preferably 8000 to 60000. The molecular weight dispersion (PDI) of the compound represented by general formula (pre-I), as measured by the method described in the examples, is preferably 1 to 8, more preferably 1 to 6, and even more preferably 1 to 4. The compound represented by general formula (pre-I) is obtained by a manufacturing method comprising steps 1 and 2 of the manufacturing method of the first embodiment.

[0034] Examples of sulfonating agents include trimethylsilyl chloride sulfate, sulfonic acid chloride, fuming sulfuric acid, and sulfuric acid. Specifically, the compound of the second embodiment of the present invention is obtained by a reaction similar to that of step 3 of the production method of the first embodiment of the present invention. The compound of the second aspect of the present invention is obtained by reacting a compound represented by general formula (pre-I) with a sulfonating agent, thereby obtaining the compound of general formula (pre-I) Ar 1 ', Ar 2 ', Ar 3 ', when R is an aromatic group 1 ', R 2 ', R 3 ', R 4 'and R 5 'and R 1 '~R 5 It is preferable that a sulfonic acid group is introduced to one or more benzene rings selected from the group consisting of rings having substituents of '.

[0035] [Polymer electrolyte fuel cell] Figure 1 is a schematic cross-sectional view showing the structure of a polymer electrolyte fuel cell (hereinafter also referred to as "fuel cell"). The polymer electrolyte fuel cell 100 has an anode catalyst layer 103, a cathode catalyst layer 105, and a solid electrolyte membrane 107 sandwiched between both catalyst layers, and each catalyst layer has a gas diffusion layer (GDL) 101 on the outside. This configuration is called a membrane electrode assembly (MEA). In a polymer electrolyte fuel cell, this membrane electrode assembly (MEA) is usually sandwiched between separators 109.

[0036] The compound represented by the general formula (I) can be used in the anode catalyst layer 103, the cathode catalyst layer 105, and the solid electrolyte membrane 107 of the fuel cell. It is preferably used in the anode catalyst layer 103 and the cathode catalyst layer 105 of the fuel cell, and more preferably used in at least the cathode catalyst layer 105 from the viewpoint of suppressing the rise in overvoltage caused by a decrease in oxygen gas diffusivity during high-current driving.

[0037] A catalyst supported on a catalyst carrier is called an electrocatalyst. In this specification, the anode catalyst layer 103 and the cathode catalyst layer 105 may be abbreviated as the catalyst layer.

[0038] Catalyst layers 103 and 105 each contain a catalyst, a catalyst support for supporting the catalyst, and an electrolyte. As the catalyst in the anode catalyst layer 103, any known metal catalyst can be used without particular limitations, and as the catalyst in the cathode catalyst layer 105, any known metal catalyst can be used without particular limitations. Examples of metal catalysts used in such anode catalyst layer 103 and cathode catalyst layer 105 include metals such as platinum, gold, silver, ruthenium, iridium, rhodium, palladium, osmium, tungsten, lead, iron, chromium, cobalt, nickel, manganese, vanadium, molybdenum, gallium, and aluminum, as well as alloys thereof and core shells thereof.

[0039] Examples of catalyst supports include carbon black such as channel black, furnace black, and thermal black; activated carbon obtained by carbonizing and activating materials containing various carbon atoms; coke; natural graphite; artificial graphite; and graphitized carbon. Carbon black is preferred because it has a high specific surface area and excellent electronic conductivity.

[0040] As the electrolyte, the compound represented by the general formula (I) above is used. The electrolyte may be the compound represented by the general formula (I) alone, or it may be optionally combined with the compound represented by the general formula (I) with at least one other electrolyte selected from the group consisting of fluorinated sulfonic acid polymers such as Nafion (registered trademark, manufactured by DuPont), Aquivion (registered trademark, manufactured by Solvay K.K.), Flemion (registered trademark, manufactured by Asahi Glass Co., Ltd.), and Aciplex (registered trademark, manufactured by Asahi Kasei Corporation), hydrocarbon sulfonic acid polymers, and partially fluorinated hydrocarbon sulfonic acid polymers.

[0041] A method for producing the anode catalyst layer 103 and the cathode catalyst layer 105 will now be described. A catalyst composition containing the compound represented by the general formula (I), a metal catalyst, and a catalyst support is prepared as a catalyst ink. The catalyst ink is then applied to a target substrate and dried to produce a catalyst layer. In addition to the compound represented by the general formula (I), the catalyst composition may also contain electrolytes other than the compound represented by the general formula (I) as an electrolyte.

[0042] Examples of suitable substrates include polymer electrolyte membranes, GDL, and sheets made of fluororesin, and catalyst layers can be fabricated using known manufacturing methods. When a catalyst ink is applied to a sheet made of fluororesin, the applied catalyst layer is transferred to the polymer electrolyte membrane. Sheets made of polytetrafluoroethylene (PTFE) are commonly used as fluororesin sheets.

[0043] The compound represented by the general formula (I) can coat the metal catalyst supported on the catalyst support with an appropriate thickness, thus maintaining the catalytic function while exhibiting good gas diffusivity and proton conductivity. The amount of the compound represented by the general formula (I) used relative to the metal catalyst is preferably 0.1 to 10 times.

[0044] The catalyst composition used as a catalyst ink may contain a binder and a solvent. A binder can be used as a component to bind catalyst supports together in order to suppress the decrease in electronic conductivity in electrode catalysts. Examples of binders include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), ethylene-propylene-diene copolymer (EPDM), fluorinated sulfonic acid polymers such as Nafion (registered trademark, manufactured by DuPont), Aquivion (registered trademark, manufactured by Solvay K.K.), Flemion (registered trademark, manufactured by Asahi Glass Co., Ltd.), and Aciplex (registered trademark, manufactured by Asahi Kasei Corporation). These may be used individually or in combination of two or more.

[0045] Examples of solvents include polar solvents such as water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, pentanol, dimethyl sulfoxide, and N,N-dimethylformamide. Water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and isobutyl alcohol are preferred solvents. These may be used individually or in combination of two or more.

[0046] The content of each component in the catalyst composition is adjusted as appropriate depending on the purpose, but in the catalyst composition, of 100% by mass of the solid content excluding the weight of the solvent, the metal catalyst is preferably 10 to 60% by mass, more preferably 30 to 50% by mass; the electrolyte containing the compound represented by the general formula (I) is preferably 5 to 50% by mass, more preferably 10 to 30% by mass; the catalyst support is preferably 20 to 75% by mass, more preferably 30 to 50% by mass; and the binder is preferably 0 to 5% by mass, more preferably 0 to 3% by mass. Components listed as both electrolytes and binders are included in the electrolyte in the above blending amounts. The solvent used in the catalyst composition is preferably 50 to 99% by mass, and more preferably 80 to 99% by mass, per 100% by mass of the catalyst composition.

[0047] Examples of materials for the solid electrolyte membrane 107 include the compound represented by the general formula (I), fluorinated sulfonic acid polymers such as Nafion (registered trademark, manufactured by DuPont), Aquivion (registered trademark, manufactured by Solvay K.K.), Flemion (registered trademark, manufactured by Asahi Glass Co., Ltd.), and Aciplex (registered trademark, manufactured by Asahi Kasei Corporation), hydrocarbon sulfonic acid polymers, and partially fluorinated hydrocarbon sulfonic acid polymers. From the viewpoint of proton conductivity, the compound represented by the general formula (I) is particularly noteworthy.

[0048] The thickness of the solid electrolyte membrane 107 is preferably 10 to 100 μm, and more preferably 20 to 60 μm, from the viewpoint of conductivity, durability, and gas cross-leakage.

[0049] There are no particular restrictions on the gas diffusion layer 101, but conductive porous materials are preferably used. Examples of such materials include carbon paper and nonwoven fabrics, felt, and nonwoven fabrics. The above describes the compound represented by general formula (I) in the first aspect of the present invention, but the compound in the second aspect of the present invention can also be used in the same manner as the compound represented by general formula (I). [Examples]

[0050] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. [Methods for measuring number-average molecular weight (Mn) and weight-average molecular weight (Mw)] These are the measurement results obtained by gel permeation chromatography (hereinafter abbreviated as GPC). A GPC instrument manufactured by Tosoh Corporation was used for the measurement, and the measurement conditions were as follows. GPC columns: TSKgel SuperHZM-N; TSKgel SuperHZ3000; TSKgel SuperHZ2000 (Tosoh Corporation) Column temperature: 40℃ Solvent: Tetrahydrofuran (THF) Flow rate: 0.6ml / min Standard sample: Polystyrene (Tosoh Corporation)

[0051] [Synthesis Example 1: Synthesis of Compound M-1] [ka]

[0052] (1) Synthesis of Int-1 Under a nitrogen atmosphere, 5.16 g of 2,2'-(1,4-phenylene)bis(1-phenylene-1,2-dione) and 6.66 g of 1,3-diphenylpropan-2-one were placed in a reaction vessel, and 320 ml of ethanol was added. The reaction mixture was heated and refluxed, and a solution prepared with 1.69 g of potassium hydroxide and 8 ml of ethanol was added dropwise. The mixture was stirred under heating and reflux conditions for 30 minutes. After cooling to room temperature, the mixture was stirred for another hour while cooling in an ice bath, and then filtered. The resulting filtrate was dried to obtain 8.94 g of the target Int-1 (yield 86%). 1 H NMR(500MHz,DMSO-d6)δ(ppm):7.21-7.24(m,12H),7.15-7.18(m,4H),6.92-6.93(m,4H).

[0053] (2) Synthesis of Int-2 Under a nitrogen atmosphere, 12 g of Int-1 and 6.2 g of 1-bromo-4-ethynylbenzene were placed in a reaction vessel, and 60 mL of nitrobenzene was added. The reaction mixture was heated to 180°C and stirred for 7 hours. After cooling to room temperature, the mixture was added dropwise to methanol, stirred, filtered, and the filtrate was dried to obtain 15 g of the target Int-2 (yield 91%).

[0054] (3) Synthesis of Int-3 Under a nitrogen atmosphere, 10 g of Int-2, 5.7 g of bis(pinacolato)diborone, 0.91 g of [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II)dichloromethane adduct, 5.5 g of potassium acetate, and 70 mL of N,N-dimethylformamide were added to a reaction vessel. The reaction mixture was heated to 150°C and stirred for 18 hours. After cooling to room temperature, the mixture was added dropwise to deionized water, stirred, filtered, and the filtrate was dried. After dissolving the dried filtrate, it was separated and purified by column chromatography (chloroform / hexane = 1 / 1) to obtain 7.4 g of the target Int-3 (yield 68%). 1 H NMR(500MHz,CDCl3)δ(ppm):7.60(d,J=8.0Hz,2H),7.55(s,1H),7.18(d,J=8.0Hz,2H),7 .14-7.16(m,5H),6.90-6.92(m,6H),6.83-6.87(m,7H),6.76-6.78(m,2H),1.32(s,12H).

[0055] (4) Synthesis of M-1 Under a nitrogen atmosphere, 7.0 g of Int-3, 6.5 g of 1,3-dibromo-5-iodobenzene, and 0.70 g of tetrakistriphenylphosphine palladium were placed in a reaction vessel, and 100 mL of 2M potassium carbonate aqueous solution, 70 mL of ethanol, and 175 mL of toluene were added. The reaction mixture was heated to 80°C and stirred for 3.5 hours. After cooling to room temperature, liquid-liquid extraction was performed, and the resulting organic layer was dried over sodium sulfate. The concentrate was concentrated, and the resulting concentrate was separated and purified by column chromatography (chloroform / hexane = 1 / 3 to 1 / 1 gradient) to obtain 7.4 g of the target M-1 (yield 89%). 1 H NMR(500MHz,CDCl3)δ(ppm):7.61-7.62(m,2H),7.59(m,2H),7.34(d,J=8.0Hz,2H),7.24 (d,J=8.0Hz,2H),7.16(m,5H),6.93-6.96(m,6H),6.84-6.88(m,7H),6.78-6.80(m,2H).

[0056] [Synthesis Example 2: Synthesis of Compound M-2] [ka]

[0057] (1) Synthesis of Int-4 Under a nitrogen atmosphere, 5.0 g of 1,3-dibromo-5-iodobenzene, 0.29 g of bis(triphenylphosphine)palladium dichloride, 0.081 g of copper iodide, 0.11 g of triphenylphosphine, and 1.5 g of trimethylsilylacetylene were placed in a reaction vessel, and 5 mL of tetrahydrofuran and 10 mL of triethylamine were added. The reaction mixture was heated to 50°C and stirred for 8.5 hours. After the reaction mixture was cooled to room temperature, it was filtered by silica gel, and the resulting filtrate was concentrated to dryness. Hexane was added to dissolve the filtrate, and it was separated and purified by column chromatography (hexane) to obtain 4.0 g of the target Int-4 (yield 87%). 1 H NMR(500MHz,CDCl3)δ(ppm):7.61(t,J=2.0Hz,1H),7.53(d,J=2.0Hz,2H),0.24(s,9H).

[0058] (2) Synthesis of Int-5 In a reaction vessel, 4.0 g of Int-4 and 5.0 g of potassium carbonate were added, and 50 mL of methanol was added. The reaction mixture was stirred at room temperature for 72 hours. The reaction mixture was filtered, and the resulting filtrate was concentrated and allowed to dry. It was dissolved in chloroform, and liquid-liquid separation was performed by adding deionized water (twice). The organic layer was dried over sodium sulfate, then concentrated and dried to obtain 2.4 g of the target Int-5 (yield 75%). 1 H NMR(500MHz,CDCl3)δ(ppm):7.66(t,J=1.5Hz,1H),7.56(d,J=1.5Hz,2H),3.16(s,1H).

[0059] (3) Synthesis of M-2 Under a nitrogen atmosphere, 3.4 g of Int-1 and 2.3 g of Int-5 were placed in a reaction vessel, and 20 mL of nitrobenzene was added. The reaction mixture was heated to 180°C and stirred for 17 hours. After cooling to room temperature, the mixture was added dropwise to methanol, stirred, filtered, and the filtrate was dried to obtain 4.1 g of the target M-2 (yield 76%). 1 H NMR(500MHz,CDCl3)δ(ppm):7.49(s,1H),7.43(t,J=1.5Hz,1H),7.23(d,J=1.5Hz,2H),7.1 3-7.18(m,5H),7.00-7.01(m,3H),6.92-6.94(m,3H),6.82-6.88(m,7H),6.76-6.78(m,2H).

[0060] [Synthesis Example 3: Synthesis of M-3] [ka]

[0061] (1) Synthesis of Int-6 Under a nitrogen atmosphere, 25.0 g of 1,4-bisbenzyl and 32.3 g of 1,3-diphenylpropan-2-one were added, and 200 g of ethanol was added. The reaction mixture was heated and refluxed, and a solution prepared with 8.23 ​​g of potassium hydroxide and 50 g of ethanol was added dropwise. The mixture was stirred under heating and reflux conditions for 30 minutes. After cooling to room temperature, the mixture was stirred for another hour, and then filtered. The resulting filtrate was dried to obtain 41.7 g of the target Int-6 (yield 83%). 1 H NMR(500MHz,CDCl3)δ(ppm):7.59(m,4H),7.28-7.21(m,22H),7.19(m,4H),7.05(m,4H),6.94(m,4H).

[0062] (2) Synthesis of M-3 Under a nitrogen atmosphere, 20.0 g of Int-6 and 11.0 g of 1-bromo-4-ethynylbenzene were placed in a reaction vessel, and 100 mL of nitrobenzene was added. The reaction mixture was heated to 180°C and stirred for 19 hours. After cooling to room temperature, the mixture was added dropwise to methanol, stirred, filtered, and the filtrate was dried to obtain 26.8 g of the target M-3 (yield 93%). 1 H NMR(500MHz,CDCl3)δ(ppm):7.45(m,2H),7.28-7.26(m,4H),7.23-7.20(m,3H),7.15-7.14(m,3H),7.10-7.07(m,3H) ,7.04-6.92(m,17H),6.79-6.76(m,3H),6.72-6.69(m,4H),6.66-6.64(m,1H),6.41(m,1H),6.34(m,2H),6.27(s,1H).

[0063] [Example 1: Synthesis of Electrolyte 1] (1) Synthesis of P-1 [ka] Under a nitrogen atmosphere, 0.70 g of M-1, 0.30 g of 2,2',3,3',5,5',6,6'-octafluorobiphenyl, 0.0096 g of tris(dibenzylideneacetone)dipalladium, 0.015 g of tris(o-methoxyphenyl)phosphine, 1.1 g of cesium carbonate, and 0.10 g of pivalic acid were placed in a reaction vessel, and 8 mL of cyclopentyl methyl ether was added. The reaction mixture was heated to 105°C and stirred for 9.5 hours. After cooling to room temperature, the reaction mixture was added dropwise to a methanol-ion-exchanged water mixture and stirred. The mixture was filtered, and the resulting filtrate was dried and dissolved in tetrahydrofuran. This was then added dropwise to a 0.2% N,N-diethyldithiocarbamate sodium trihydrate methanol solution and stirred. The mixture was filtered, and the resulting filtrate was dried to obtain 0.54 g of the target P-1 (yield 65%). Mn16400 (PDI 1.69)

[0064] (2) Synthesis of electrolyte 1 In a reaction vessel, 0.30 g of P-1 and 15 mL of methylene chloride were added, and 0.79 g of trimethylsilyl chlorosulfonate was added. The reaction mixture was stirred at room temperature for 2 hours, and then ethanol was added to stop the reaction. The reaction mixture was added dropwise to diethyl ether, stirred, filtered, and the resulting filtrate was dried to obtain electrolyte 1, in which a sulfonic acid group was introduced into P-1.

[0065] [Example 2: Synthesis of Electrolyte 2] (1) Synthesis of P-2 [ka]

[0066] Under a nitrogen atmosphere, 0.59 g of M-1, 0.036 g of 1,4-dibromobenzene, 0.30 g of 2,2',3,3',5,5',6,6'-octafluorobiphenyl, 0.0094 g of tris(dibenzylideneacetone)dipalladium, 0.014 g of tris(o-methoxyphenyl)phosphine, 1.1 g of cesium carbonate, and 0.10 g of pivalic acid were placed in a reaction vessel, and 8 mL of cyclopentyl methyl ether was added. The reaction mixture was heated to 105°C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was added dropwise to a methanol-ion-exchanged water mixture and stirred. The mixture was filtered, and the resulting filtrate was dried, dissolved in tetrahydrofuran, and added dropwise to a 0.3% N,N-diethyldithiocarbamate sodium trihydrate methanol solution and stirred. The sample was filtered, and the resulting filtrate was dried to obtain 0.68 g of the target P-2 (yield 89%). Mn32600 (PDI 2.08)

[0067] (2) Synthesis of electrolyte 2 0.30 g of P-2 and 15 mL of methylene chloride were placed in a reaction vessel, and 0.44 g of trimethylsilyl chlorosulfonate was added. The reaction mixture was stirred at room temperature for 14 hours, and then ethanol was added to stop the reaction. The reaction mixture was added dropwise to diethyl ether, stirred, filtered, and the resulting filtrate was dried to obtain 0.32 g of electrolyte 2, in which a sulfonic acid group was introduced into P-2.

[0068] [Example 3: Synthesis of Electrolyte 3] (1) Synthesis of P-3 [ka]

[0069] Under a nitrogen atmosphere, 0.35 g of M-1, 0.12 g of 1,3-dibromobenzene, 0.30 g of 2,2',3,3',5,5',6,6'-octafluorobiphenyl, 0.0096 g of tris(dibenzylideneacetone)dipalladium, 0.015 g of tris(o-methoxyphenyl)phosphine, 1.1 g of cesium carbonate, and 0.10 g of pivalic acid were placed in a reaction vessel, and 9 mL of cyclopentyl methyl ether was added. The reaction mixture was heated to 105°C and stirred for 22 hours. After cooling to room temperature, the reaction mixture was added dropwise to a methanol-ion-exchanged water mixture and stirred. The mixture was filtered, and the resulting filtrate was dried, dissolved in tetrahydrofuran, and added dropwise to a 0.4% N,N-diethyldithiocarbamate sodium trihydrate methanol solution and stirred. The sample was filtered, and the resulting filtrate was dried to obtain 0.32 g of the target P-3 (yield 52%). Mn21600 (PDI 2.33)

[0070] (2) Synthesis of electrolyte 3 0.30 g of P-3 and 15 mL of methylene chloride were placed in a reaction vessel, and 0.57 g of trimethylsilyl chlorosulfonate was added. The reaction mixture was stirred at room temperature for 19 hours, and then ethanol was added to stop the reaction. The reaction mixture was added dropwise to diethyl ether, stirred, filtered, and the resulting filtrate was dried to obtain 0.27 g of electrolyte 3, in which a sulfonic acid group was introduced into P-3.

[0071] [Example 4: Synthesis of Electrolyte 4] (1) Synthesis of P-4 [ka]

[0072] Under a nitrogen atmosphere, 0.49 g of M-1, 0.071 g of 1,4-dibromobenzene, 0.15 g of 1,2,4,5-tetrafluorobenzene, 0.0093 g of tris(dibenzylideneacetone)dipalladium, 0.014 g of tris(o-methoxyphenyl)phosphine, 1.1 g of cesium carbonate, and 0.10 g of pivalic acid were placed in a reaction vessel, and 9 mL of cyclopentyl methyl ether was added. The reaction mixture was heated to 105°C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was added dropwise to a methanol-ion-exchanged water mixture and stirred. The mixture was filtered, and the resulting filtrate was dried and dissolved in tetrahydrofuran. This was then added dropwise to a 0.3% N,N-diethyldithiocarbamate sodium trihydrate methanol solution and stirred. The mixture was filtered, and the resulting filtrate was dried to obtain 0.50 g of the target P-4 (yield 92%). Mn20300 (PDI 1.80)

[0073] (2) Synthesis of electrolyte 4 0.30 g of P-4 and 15 mL of methylene chloride were placed in a reaction vessel, and 0.61 g of trimethylsilyl chlorosulfonate was added. The reaction mixture was stirred at room temperature for 15 hours, and then ethanol was added to stop the reaction. The reaction mixture was added dropwise to diethyl ether, stirred, filtered, and the resulting filtrate was dried to obtain 0.39 g of electrolyte 4, in which a sulfonic acid group was introduced into P-4.

[0074] [Example 5: Synthesis of Electrolyte 5] (1) Synthesis of P-5 [ka]

[0075] Under a nitrogen atmosphere, 0.50 g of M-2, 0.083 g of 1,4-dibromobenzene, 0.17 g of 1,2,4,5-tetrafluorobenzene, 0.011 g of tris(dibenzylideneacetone)dipalladium, 0.016 g of tris(o-methoxyphenyl)phosphine, 1.2 g of cesium carbonate, and 0.12 g of pivalic acid were placed in a reaction vessel, and 9 mL of cyclopentyl methyl ether was added. The reaction mixture was heated to 105°C and stirred for 21.5 hours. After cooling to room temperature, the reaction mixture was added dropwise to a methanol-ion-exchanged water mixture and stirred. The mixture was filtered, and the resulting filtrate was dried and dissolved in tetrahydrofuran. This was then added dropwise to a 0.3% N,N-diethyldithiocarbamate sodium trihydrate methanol solution and stirred. The mixture was filtered, and the resulting filtrate was dried to obtain 0.50 g of the target P-5 (yield 89%). Mn23700 (PDI 2.43)

[0076] (2) Synthesis of electrolyte 5 0.30 g of P-5 and 15 mL of methylene chloride were placed in a reaction vessel, and 0.66 g of trimethylsilyl chlorosulfonate was added. The reaction mixture was stirred at room temperature for 13 hours, and then ethanol was added to stop the reaction. The reaction mixture was added dropwise to diethyl ether, stirred, filtered, and the resulting filtrate was dried to obtain 0.26 g of electrolyte 5, in which a sulfonic acid group was introduced into P-5.

[0077] [Example 6: Synthesis of Electrolyte 6] (1) Synthesis of P-6 [ka]

[0078] Under a nitrogen atmosphere, 0.50 g of M-2, 0.12 g of 1,2,4,5-tetrafluorobenzene, 0.0074 g of tris(dibenzylideneacetone)dipalladium, 0.012 g of tris(o-methoxyphenyl)phosphine, 0.87 g of cesium carbonate, and 0.084 g of pivalic acid were placed in a reaction vessel, and 9 mL of cyclopentyl methyl ether was added. The reaction mixture was heated to 105°C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was added dropwise to a methanol-ion-exchanged water mixture and stirred. The mixture was filtered, and the resulting filtrate was dried and dissolved in tetrahydrofuran. This was then added dropwise to a 0.2% N,N-diethyldithiocarbamate sodium trihydrate methanol solution and stirred. The mixture was filtered, and the resulting filtrate was dried to obtain 0.44 g of the target P-6 (yield 90%). Mn8400 (PDI 1.56)

[0079] (2) Synthesis of electrolyte 6 In a reaction vessel, 0.31 g of P-6 and 15 mL of methylene chloride were added, and 0.55 g of trimethylsilyl chlorosulfonate was added. The reaction mixture was stirred at room temperature for 12.5 hours, and then ethanol was added to stop the reaction. The reaction mixture was added dropwise to diethyl ether, stirred, filtered, and the resulting filtrate was dried to obtain 0.34 g of electrolyte 6, in which a sulfonic acid group was introduced into P-6.

[0080] [Example 7: Synthesis of Electrolyte 7] (1) Synthesis of P-7 [ka]

[0081] Under a nitrogen atmosphere, 0.50 g of M-2, 0.16 g of 2,2'-dibromo-9,9'-spirobi[9H-fluorene], 0.17 g of 1,2,4,5-tetrafluorobenzene, 0.011 g of tris(dibenzylideneacetone)dipalladium, 0.016 g of tris(o-methoxyphenyl)phosphine, 1.2 g of cesium carbonate, and 0.12 g of pivalic acid were placed in a reaction vessel, and 9 mL of cyclopentyl methyl ether was added. The reaction mixture was heated to 105°C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was added dropwise to a methanol-ion-exchanged water mixture and stirred. The mixture was filtered, and the resulting filtrate was dried, dissolved in tetrahydrofuran, and added dropwise to a 0.5% N,N-diethyldithiocarbamate sodium trihydrate methanol solution and stirred. The sample was filtered, and the resulting filtrate was dried to obtain 0.54 g of the target P-7 (yield 84%). Mn20400 (PDI 2.25)

[0082] (2) Synthesis of electrolyte 7 0.30 g of P-7 and 15 mL of methylene chloride were placed in a reaction vessel, and 0.57 g of trimethylsilyl chlorosulfonate was added. The reaction mixture was stirred at room temperature for 13.5 hours, and then ethanol was added to stop the reaction. The reaction mixture was added dropwise to diethyl ether, stirred, filtered, and the resulting filtrate was dried to obtain 0.30 g of electrolyte 7, in which a sulfonic acid group was introduced into P-7.

[0083] [Example 8: Synthesis of Electrolyte 8] (1) Synthesis of P-8 [ka]

[0084] Under a nitrogen atmosphere, 0.58 g of M-2, 0.097 g of 1,3-dibromobenzene, 0.40 g of 2,2',3,3',5,5',6,6'-octafluorobiphenyl, 0.013 g of tris(dibenzylideneacetone)dipalladium, 0.019 g of tris(o-methoxyphenyl)phosphine, 1.4 g of cesium carbonate, and 0.14 g of pivalic acid were placed in a reaction vessel, and 10 mL of cyclopentyl methyl ether was added. The reaction mixture was heated to 105°C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was added dropwise to a methanol-ion-exchanged water mixture and stirred. The mixture was filtered, and the resulting filtrate was dried, dissolved in tetrahydrofuran, and added dropwise to a 1.0% N,N-diethyldithiocarbamate sodium trihydrate methanol solution and stirred. The sample was filtered, and the resulting filtrate was dried to obtain 0.72 g of the target P-8 (85% yield). Mn18200 (PDI 2.12)

[0085] (2) Synthesis of electrolyte 8 0.30 g of P-8 and 15 mL of methylene chloride were placed in a reaction vessel, and 0.51 g of trimethylsilyl chlorosulfonate was added. The reaction mixture was stirred at room temperature for 14 hours, and then ethanol was added to stop the reaction. The reaction mixture was added dropwise to diethyl ether, stirred, filtered, and the resulting filtrate was dried to obtain 0.14 g of electrolyte 8, in which a sulfonic acid group was introduced into P-8.

[0086] [Comparative Example 1: Synthesis of Electrolyte 9] (1) Synthesis of P-9 [ka]

[0087] Under a nitrogen atmosphere, 0.32 g of 3,5-dibromoviphenyl, 0.30 g of 2,2',3,3',5,5',6,6'-octafluorobiphenyl, 0.0098 g of tris(dibenzylideneacetone)dipalladium, 0.014 g of tris(o-methoxyphenyl)phosphine, 1.1 g of cesium carbonate, and 0.10 g of pivalic acid were placed in a reaction vessel, and 6 mL of cyclopentyl methyl ether was added. The reaction mixture was heated to 105°C and stirred for 23.5 hours. After cooling to room temperature, the reaction mixture was added dropwise to a methanol-ion-exchanged water mixture and stirred. The mixture was filtered, and the resulting filtrate was dried and dissolved in tetrahydrofuran. This solution was then added dropwise to a 0.3% N,N-diethyldithiocarbamate sodium trihydrate methanol solution and stirred. The mixture was filtered, and the resulting filtrate was dried to obtain 0.36 g of the target P-9 (yield 80%). Mn25200 (PDI 2.36)

[0088] (2) Synthesis of electrolyte 9 0.30 g of P-9 and 15 mL of methylene chloride were placed in a reaction vessel, and 0.37 g of trimethylsilyl chlorosulfonate was added. The reaction mixture was stirred at room temperature for 23 hours, and then ethanol was added to stop the reaction. The reaction mixture was added dropwise to diethyl ether, stirred, filtered, and the resulting filtrate was dried to obtain 0.30 g of electrolyte 9, in which a sulfonic acid group was introduced into P-9.

[0089] [Comparative Example 2: Synthesis of P-10] [ka]

[0090] Under a nitrogen atmosphere, 0.47 g of 3,5-dibromo-5'-phenyl-1,1':3',1''-terphenyl, 0.30 g of 2,2',3,3',5,5',6,6'-octafluorobiphenyl, 0.0091 g of tris(dibenzylideneacetone)dipalladium, 0.014 g of tris(o-methoxyphenyl)phosphine, 1.1 g of cesium carbonate, and 0.10 g of pivalic acid were placed in a reaction vessel, and 6 mL of cyclopentyl methyl ether was added. The reaction mixture was heated to 105°C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was added dropwise to a methanol-ion-exchanged water mixture and stirred. The mixture was filtered, and the resulting filtrate was dried to obtain the target P-10. However, due to the low solubility of the obtained P-10, molecular weight measurement could not be performed.

[0091] [Comparative Example 3: Synthesis of P-11] [ka] Under a nitrogen atmosphere, 0.74 g of 3,5-dibromo-5'-phenyl-1,1':3',1''-terphenyl, 0.16 g of 1,4-dibromobenzene, 0.35 g of 1,2,4,5-tetrafluorobenzene, 0.021 g of tris(dibenzylideneacetone)dipalladium, 0.032 g of tris(o-methoxyphenyl)phosphine, 2.4 g of cesium carbonate, and 0.23 g of pivalic acid were placed in a reaction vessel, and 5 mL of cyclopentyl methyl ether was added. The reaction mixture was heated to 105°C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was added dropwise to a methanol-ion-exchanged water mixture and stirred. The mixture was filtered, and the resulting filtrate was dried to obtain the target P-11. However, due to the low solubility of the obtained P-11, molecular weight measurement could not be performed.

[0092] [Comparative Example 4: Synthesis of Electrolyte 10] (1) Synthesis of P-12 [ka]

[0093] Under a nitrogen atmosphere, 1.50 g of M-3, 0.27 g of 1,2,3,5-tetrafluorobenzene, 0.014 g of tris(dibenzylideneacetone)dipalladium, 0.022 g of tris(o-methoxyphenyl)phosphine, 1.62 g of cesium carbonate, and 0.16 g of pivalic acid were placed in a reaction vessel, and 17 mL of cyclopentyl methyl ether was added. The reaction mixture was heated to 105°C and stirred for 19 hours. After cooling to room temperature, the reaction mixture was added dropwise to a methanol-ion-exchanged water mixture and stirred. The mixture was filtered, and the resulting filtrate was dried and dissolved in tetrahydrofuran. This solution was then added dropwise to a 0.2% N,N-diethyldithiocarbamate sodium trihydrate methanol solution and stirred. The mixture was filtered, and the resulting filtrate was dried to obtain 1.26 g of the target P-12 (yield 85%). Mn10100 (PDI 1.90)

[0094] (2) Synthesis of electrolyte 10 0.30 g of P-12 and 15 mL of methylene chloride were placed in a reaction vessel, and 1.66 g of trimethylsilyl chlorosulfonate was added. The reaction mixture was stirred at room temperature for 15.5 hours, and then ethanol was added to stop the reaction. The reaction mixture was added dropwise to diethyl ether, stirred, filtered, and the resulting filtrate was dried to obtain 0.39 g of electrolyte 10, in which a sulfonic acid group was introduced into P-12.

[0095] [Confirmation of solubility of polymers P-1 to P-12 before introduction of sulfonic acid groups] To confirm the solubility in the solvent used in the reaction to introduce sulfonic acid groups, an amount of polymer equal to 0.25% by mass of each solution was added to chloroform solvent and evaluated according to the following criteria. ○: No polymer residue was found, and a 0.25% by mass solution was prepared. ×: Undissolved polymer particles remained, making it impossible to prepare a 0.25% by mass solution. The results are shown in Table 1.

[0096] [Confirmation of solubility of electrolytes 1-10] To confirm the solubility of the catalyst ink in polar solvents, an amount of electrolyte equal to a 5% solution was added to a 1-propanol / exchanged water (1 part by mass / 1 part by mass) mixed solvent, and evaluated according to the following criteria. The results are shown in Table 1. ○: No electrolyte residue remained, and a 5% by mass solution was prepared. ×: Undissolved electrolytes remained, making it impossible to prepare a 5% by mass solution.

[0097] [Preparation of catalytic ink] In a glass container, 0.25 g of platinum-supported carbon catalyst (TEC10E50E, manufactured by Tanaka Kikinzoku Kogyo Co., Ltd.), 4.5 g of deionized water, 4.5 g of 1-propanol, and 1.3 g of a 5% water / 1-propanol (1 part by mass / 1 part by mass) solution of the electrolyte synthesized in Examples 1-8 and Comparative Example 1 were added, and the mixture was ultrasonically irradiated in a homogenizer for 20 minutes to prepare a catalyst ink.

[0098] [Creation of gas diffusion electrodes] A gas diffusion layer with a microporous layer (SIGRACET GDL28BC, made of SGL carbon) was placed on an 80°C hot plate, and the catalyst ink prepared using the method described above was sprayed onto the microporous layer to create a gas diffusion electrode with a catalyst layer formed on the microporous layer.

[0099] [Creation of membrane-electrode junctions] A pair of gas diffusion electrodes, prepared as described above, were sandwiched between two sides of an electrolyte membrane (Nafion NR212, 50 μm thick, manufactured by Chemours). A membrane-electrode assembly was then fabricated by hot pressing under conditions of 0.47 kN and 140°C for 10 minutes.

[0100] [Power generation evaluation] A polymer electrolyte fuel cell was created by covering the membrane-electrode assembly obtained above with a pair of gaskets, except for the electrode portion, and arranging separators (which also serve as gas flow paths), current collectors, insulating sheets, and clamping plates on both sides. This was used as a single cell, with one side serving as the oxygen electrode supplied with air, and the other side as the fuel electrode supplied with hydrogen to generate electricity. The power generation conditions were a cell temperature of 80°C, relative humidity on both the air and fuel sides of 50% RH, and the fuel and oxygen utilization rates were set to 2% for each gas supply. Power generation performance was evaluated at 0.8, 0.6, and 0.4 A / cm². 2 The output voltage at that time is shown in Table 1.

[0101] [Table 1] As shown in Table 1, Examples 1-8 exhibited higher solubility in polar solvents than Comparative Examples 1-4, and since power generation using the cells was possible, it was confirmed that they could be used as electrolytes. [Explanation of Symbols]

[0102] 100 Polymer electrolyte fuel cell 101 Gas diffusion layer 103 Anode catalyst layer 105 Cathode catalyst layer 107 Solid electrolyte membrane 109 Separator

Claims

1. A compound having a structure represented by the following general formula (I). 【Chemistry 1】 (In general formula (I), Ar １ It has an aromatic structure, and is sometimes substituted with a sulfonic acid group. Ar ２ It has an aromatic structure, and is sometimes substituted with a sulfonic acid group. Ar ３ It has an aromatic structure, and is sometimes substituted with a sulfonic acid group. However, when p = 1, Ar ２ It is a benzene ring, which is sometimes substituted with a sulfonic acid group. R １ ~R ５ Each of these is independently a hydrogen atom, a sulfonic acid group, or an aromatic group, and each aromatic group is independently, sometimes substituted with a sulfonic acid group. R １ ~R ５ One of them is a hydrogen or sulfonic acid group, and the other four are aromatic groups. Ar １ 、Ar ２ 、Ar ３ 、 when R is an aromatic group １ 、R ２ 、R ３ 、R ４ and R ５ and one or more selected from the group consisting of benzene ring A have one or more sulfonic acid groups, l and m are mole fractions when l + m = 1.0, where 0 < l ≤ 1.0 and 0 ≤ m < 1.

0. If m is not 0, then each constituent unit undergoes random copolymerization. n is an integer from 1 to 3, independently of each other. p is either 0 or 1.

2. A compound obtained by reacting a compound represented by the following general formula (pre-I) with a sulfonating agent. 【Chemistry 2】 (In the general formula (pre-I), Ar １ ' is an aromatic structure, Ar ２ ' is an aromatic structure, Ar ３ ' is an aromatic structure, However, when p = 1, Ar ２ ' is a benzene ring, R １ '~R ５ Each of these is independently either a hydrogen atom or an aromatic group. R １ '~R ５ One of the elements in the '' is hydrogen, and the other four are aromatic groups. l and m are mole fractions when l + m = 1.0, where 0 < l ≤ 1.0 and 0 ≤ m < 1.

0. If m is not 0, then each constituent unit undergoes random copolymerization. n is an integer from 1 to 3, independently of each other. p is either 0 or 1.

3. In the above general formula (I), Ar １ but, 【Transformation 3】 The compound according to claim 1, which is selected from the group consisting of (wherein X is independently hydrogen, an alkyl group having 1 to 8 carbon atoms, or a phenyl group), and is optionally substituted with a sulfonic acid group.

4. In the above general formula (I), R when it is aromatic １ ~R ５ However, each independently 【Chemistry 4】 The compound according to claim 1, which is selected from the group consisting of the following, and is optionally substituted with a sulfonic acid group.

5. In the above general formula (pre-I), Ar １ 'but, 【Transformation 5】 The compound according to claim 2, which is one selected from the group consisting of (wherein X is independently hydrogen, an alkyl group having 1 to 8 carbon atoms, or a phenyl group).

6. In the above general formula (pre-I), R when it is aromatic １ '~R ５ ', each independently 【Transformation 6】 The compound according to claim 2, which is one selected from the group consisting of the following.

7. A compound according to any one of claims 1 to 6, used as an electrolyte for the anode catalyst layer and / or cathode catalyst layer of a polymer electrolyte fuel cell.

8. A catalyst layer for a polymer electrolyte fuel cell comprising the compound described in any one of claims 1 to 6.

9. A catalyst composition comprising a compound, a metal catalyst, and a catalyst support according to any one of claims 1 to 6.

10. The catalyst composition according to claim 9, for use in polymer electrolyte fuel cells.

11. A catalyst layer for a polymer electrolyte fuel cell comprising the catalyst composition described in claim 10.

12. A membrane electrode assembly having a solid electrolyte membrane, a gas diffusion layer, and a catalyst layer according to claim 11.

13. A polymer electrolyte fuel cell having the membrane electrode assembly described in claim 12.

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