JP6278507B2 - Polymer electrolyte for fuel cell, catalyst electrode for fuel cell and fuel cell using the same - Google Patents

Description

  The present invention relates to a polymer electrolyte for a fuel cell, a catalyst electrode for a fuel cell using the polymer electrolyte, and a fuel cell.

  Fluorine ionomer materials are used as polymer electrolytes used in polymer electrolyte fuel cells (PEFC). However, fuel cells using fluorine ionomer materials have room for improvement in terms of reduced output, high price, and environmental load under high temperature and low humidity.

Patent Documents 1 and 2 disclose techniques relating to hydrocarbon polymer electrolytes (hydrocarbon ionomers).
Among these, Patent Document 1 (Japanese Patent Application Laid-Open No. 2006-312742) describes using a triblock copolymer containing an aromatic ring in the main chain as a solid polymer electrolyte.
Patent Document 2 (Japanese Patent Publication No. 2009-525360) describes that a polymer blend film containing a phosphonic acid group is directly used for a methanol fuel cell.

JP 2006-31742 A Special table 2009-525360

  However, when using a hydrocarbon ionomer, the fuel gas permeability in the fuel electrode may be low. Moreover, since the hydrocarbon ionomer has the property of adsorbing to the catalyst metal, the desired characteristics may not be obtained. For these reasons, there is still room for improvement in order to put the hydrocarbon ionomer into practical use.

  The present invention has been made in view of the above circumstances, and provides a material suitable as a polymer electrolyte for a fuel cell.

（上記一般式（３）中、Ｒ³²は、炭素数２以上６以下のアルキル基であり、ｍは、前記一般式（２）におけるｍに同じである。）
また、本発明によれば、下記一般式（４）に示す構造を有する、燃料電池用高分子電解質が提供される。

（上記一般式（４）中、Ｒ²は、独立して、炭素数２以上６以下のアルキル基またはアルコキシ基であり、Ｒ⁵は、−Ｒ⁵¹−Ｃ₆Ｈ₄−基または炭素数２以上６以下のアルキレン基であり、Ｒ⁵¹は、炭素数２以上６以下のアルキレン基であり、ｍは、１０以上の正の数であり、ｎは、正の数であり、ｍ個のユニット（Ａ）およびｎ個のユニット（Ｂ）が共重合している。ただし、上記一般式（４）において、Ｒ⁵が炭素数４のアルキレン基であり、かつ、Ｒ²が炭素数４のアルコキシ基であるものを除く。））
According to the present invention, there is provided a polymer electrolyte for a fuel cell having a structure represented by the following general formula (2) or (3).

(In the general formula (3), R ³² is an alkyl group having 2 to 6 carbon atoms, and m is the same as m in the general formula (2).)
Moreover, according to this invention, the polymer electrolyte for fuel cells which has a structure shown to following General formula (4) is provided.

(In the above general formula (4), R ² is independently an alkyl group or alkoxy group having 2 to 6 carbon atoms, and R ⁵ is an —R ⁵¹ —C ₆ H ₄ — group or 2 carbon atoms. An alkylene group having 6 or less and R ⁵¹ is an alkylene group having 2 to 6 carbon atoms, m is a positive number of 10 or more, n is a positive number, and m units (A) and n units (B) are copolymerized, provided that, in the above general formula (4), R ⁵ is an alkylene group having 4 carbon atoms, and R ² is an alkoxy having 4 carbon atoms. Excluding what is the base.))

Moreover, according to this invention, the catalyst electrode for fuel cells containing the polymer electrolyte for fuel cells in the said this invention is provided.
Moreover, according to this invention, the fuel cell containing the catalyst electrode for fuel cells in the said this invention is provided.

  It should be noted that any combination of these components, or a conversion of the expression of the present invention between a method, an apparatus, and the like is also effective as an aspect of the present invention.

For example, according to the present invention, use of the polymer electrolyte for a fuel cell according to the present invention for a fuel cell is provided.
According to the present invention, there is also provided a method for producing a fuel cell catalyst electrode comprising a step of forming a fuel cell catalyst electrode using the fuel cell polymer electrolyte according to the present invention, and the fuel cell catalyst electrode. A method of manufacturing a fuel cell is provided that includes using to form a fuel cell.

  According to the present invention, a material suitable as a polymer electrolyte for a fuel cell can be provided.

It is sectional drawing which shows the structure of the fuel cell in embodiment. It is a figure which shows the measurement result by mass spectrometry (Mass Spectrometry: MS) of the compound in an Example. It is a figure which shows the MS measurement result of the compound in an Example. It is a figure which shows the MS measurement result of the compound in an Example. It is a figure which shows the MS measurement result of the compound in an Example. It is a figure which shows the MS measurement result of the compound in an Example. It is a figure which shows the MS measurement result of the compound in an Example. It is a figure which shows the MS measurement result of the compound in an Example. It is a figure which shows the MS measurement result of the compound in an Example. It is a figure which shows the evaluation result of the polymer electrolyte in an Example. It is a figure which shows the evaluation result of the polymer electrolyte in an Example. It is a figure which shows the evaluation result of MEA in an Example. It is a figure which shows the evaluation result of MEA in an Example. It is a figure which shows the evaluation result of MEA in an Example. It is a figure which shows the evaluation result of MEA in an Example. It is a figure which shows the evaluation result of MEA in an Example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, similar constituent elements are denoted by common reference numerals, and description thereof is omitted as appropriate.

  The polymer electrolyte for fuel cells in the present embodiment is a polyphenylene polymer having a main chain having an aromatic hydrocarbon skeleton, and more specifically a solid polymer electrolyte. The polymer electrolyte for fuel cells in the present embodiment has a structure represented by the following general formula (1).

(In the general formula (1), in the unit (A), R ¹ is independently a hydrogen atom, —C═OC ₆ H ₃ R ³ R ⁴ group or —OR ⁵ SO ₃ H group, m is a positive number of 10 or higher. However, the two R ¹ is not a hydrogen atom either. in unit (B), R ² is an alkyl group or an alkoxy group having 2 to 6 carbon atoms And n is 0 or a positive number.
When R ¹ is a —C═OC ₆ H ₃ R ³ R ⁴ group, R ³ is a —R ³¹ —SO ₃ H group or a —R ³² group. R ³¹ is an alkylene group having 2 to 6 carbon atoms, and R ³² is an alkyl group having 2 to 6 carbon atoms. R ⁴ is a hydrogen atom or a —SO ₃ H group. However, when R ⁴ is a hydrogen atom, R ³ is a —R ³¹ —SO ₃ H group.
When R ¹ is an —OR ⁵ SO ₃ H group, R ⁵ is an —R ⁵¹ —C ₆ H ₄ — group or an alkylene group having 2 to 6 carbon atoms, and R ⁵¹ is 2 to 6 carbon atoms. The following alkylene groups, n is not 0, and m units (A) and n units (B) are randomly copolymerized. )

The solid polymer electrolyte represented by the general formula (1) has an aromatic hydrocarbon skeleton in the main chain and a polar group and a hydrophobic group in the side chain.
The unit (A) in the general formula (1) is a unit containing a polar group in the side chain. The polar group is specifically a —SO ₃ H group.
In the general formula (1), the hydrophobic group includes a specific alkyl group, alkylene group or alkoxy group. The hydrophobic group is provided in the vicinity of the polar group in the side chain containing the polar group in the unit (A), for example. Moreover, the hydrophobic group may be provided in the unit (B).

In the unit (A), R ¹ is independently a hydrogen atom, —C═OC ₆ H ₃ R ³ R ⁴ group or —OR ⁵ SO ₃ H group. m is a positive number of 10 or more. At least one of the two R ¹ is not a hydrogen atom.
When one or more R ¹ is a —C═OC ₆ H ₃ R ³ R ⁴ group, R ³ is a —R ³¹ —SO ₃ H group or a —R ³² group. At this time, another R ¹ is, for example, a hydrogen atom.
R ³¹ is an alkylene group having 2 or more carbon atoms, preferably 3 or more carbon atoms from the viewpoint of improving gas permeability or suppressing water solubility. From the viewpoint of suppressing the decrease in the conductivity of the polymer electrolyte, R ³¹ is an alkylene group having 6 or less carbon atoms, preferably 4 or less. The alkylene group may be either linear or cyclic, such as a straight chain, or may have a branched chain.
R ³² is an alkyl group having 2 or more carbon atoms, preferably 3 or more carbon atoms from the viewpoint of improving gas permeability or suppressing water solubility. From the viewpoint of suppressing the decrease in the conductivity of the polymer electrolyte, R ³² is an alkyl group having 6 or less carbon atoms. The alkyl group may be either linear or cyclic, such as a straight chain, or may have a branched chain.
R ⁴ is a hydrogen atom or a —SO ₃ H group. However, when R ⁴ is a hydrogen atom, R ³ is a —R ³¹ —SO ₃ H group.
In addition, when R ⁴ is a —SO ₃ H group, R ³ is preferably a —R ³² group from the viewpoint of suppressing water solubility.

When R ¹ is a —C═OC ₆ H ₃ R ³ R ⁴ group, the polymer electrolyte is preferably composed of the unit (A). That is, n in the unit (B) may be 0.

In addition, from the viewpoint of water solubility suppression, gas permeability, and electrical conductivity, the polymer electrolyte in this embodiment is adjacent to the polar group —SO ₃ H group or bonded to the —SO ₃ H group. A specific alkyl chain may be provided on a carbon atom adjacent to the carbon atom to be formed. For example, one of two R ¹ may be a hydrogen atom, and the other may be a —C═OC ₆ H ₃ R ³ R ⁴ group. More specifically, the above general formula (2) or ( You may have the structure shown to 3).

(In the general formula (2), R ³¹ and m are the same as R ³¹ and m in the general formula (1), respectively.)

(In the general formula (3), R ³² and m are the same as R ³² and m in the general formula (1), respectively.)

Further, in the above, R ¹ is ^{_{-C = OC 6 H 3 R 3}} R 4 group, although the polymer electrolyte is an example constituted by a unit (A), in the unit (B) (B) Is not 0, that is, the polymer electrolyte may be a copolymer of the units (A) and (B). At this time, there is no restriction | limiting in the form of superposition | polymerization of unit (A) and (B), It can be set as any aspect of a random copolymer and a block copolymer.

In the unit (B), R ² is an alkyl group or alkoxy group having 2 to 6 carbon atoms. The alkyl group or alkoxy group may be linear or other chain and cyclic, and may have a branched chain.

Next, an example in which R ¹ in the unit (A) is a —OR ⁵ SO ₃ H group will be described. For example, when both R ¹ are —OR ⁵ SO ₃ H groups, the general formula (1) has the following structure.

(In the general formula (4), R ² , R ⁵ , m and n are the same as R ² , R ⁵ , m and n in the general formula (1), respectively.)

The general formula (4) is an example of a structure in which the hydrophobic group is provided in a unit other than the unit containing the polar group in addition to the unit containing the polar group.
R ⁵ is a —R ⁵¹ —C ₆ H ₄ — group or an alkylene group having 2 to 6 carbon atoms. The alkylene group may be either linear or cyclic, such as a straight chain, or may have a branched chain.
When R ⁵ is a —R ⁵¹ —C ₆ H ₄ — group, R ⁵¹ is an alkylene group having 2 or more carbon atoms, and from the viewpoint of improving gas permeability, it has 2 or more carbon atoms, preferably 3 or more carbon atoms. An alkylene group; From the viewpoint of suppressing the decrease in the conductivity of the polymer electrolyte, R ⁵¹ is an alkylene group having 6 or less carbon atoms, preferably 4 or less. The alkylene group may be either linear or cyclic, such as a straight chain, or may have a branched chain.
In the general formula (4), n is not 0, and m units (A) and n units (B) are randomly copolymerized.
Also, the unit ratio of m and n is an ion exchange capacity of the polymer electrolyte: it can be determined in accordance with (ion exchange capacity IEC), for example IEC is 0.8 meq g ^-1 or more 3.3 meq g ^-1 or less and The unit ratio can be as follows.

Next, the manufacturing method of the polymer electrolyte in this embodiment is demonstrated.
The polymer electrolyte in this embodiment is, for example,
A step of preparing a dihalogenophenylbenzene monomer corresponding to the unit (A) or the unit (B) by a predetermined method (step 1);
A step of obtaining a polymer by polymerizing the monomer prepared in step 1 or its converter by acting a catalyst (step 2);
After the step 2, there is a step (step 3) of deprotecting the sulfone group in the polymer to obtain the polymer electrolyte represented by the general formula (1).
Hereinafter, each process will be described.

  In step 1, a dihalogenophenylbenzene monomer is prepared according to the structure of the polymer electrolyte to be produced. Examples of monomers corresponding to the units (A) and (B) are shown in the following general formulas (11) and (12), respectively.

(In the general formula (11), R ^{1 ′} is a group in which the sulfonic acid group is protected in R ¹ in the general formula (1), and X ¹ is halogen.)

(In the general formula (12), R ² is R ² in the general formula (1), X ² is halogen.)

In the general formula (11), examples of the protective group for the sulfonic acid group include a hydrocarbon group having 2 to 10 carbon atoms. The hydrocarbon group may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and examples of the aliphatic hydrocarbon group include a linear or branched chain alkyl group and a cyclic alkyl group.
More specifically, as a protecting group for a sulfonic acid group, a butyl group such as an n-butyl group, an isobutyl group or a t-butyl group; a pentyl group such as an n-pentyl group, an isopentyl group or a neopentyl group, a cyclopentyl group, n -A hexyl group such as a hexyl group; a cyclohexyl group, a dimethylphenyl group, and the like.

  In the general formulas (11) and (12), examples of the halogen include fluorine, chlorine, bromine, and iodine.

  In step 2, a polymer is obtained by polymerizing the monomer or its converted product by acting a catalyst. Examples of the polymerization method include a catalyst transfer type condensation polymerization method and a Ni (0) (zero-valent nickel) coupling polymerization method.

  Hereinafter, the catalyst transfer type condensation polymerization method will be described as an example. The polymerization conditions can be determined according to the type of monomer, catalyst, Grignard reagent, etc. Specific conditions will be described later in the Examples section.

  As the catalyst, for example, a halogen complex of a transition metal such as nickel, palladium or cobalt is used. Specifically, [1,2-bis (diphenylphosphino) ethane] dichloronickel (II), [1,3-bis (diphenylphosphino) propane] nickel (II) dichloride, bis (triphenylphosphine) nickel (II) Nickel catalysts such as dichloride are listed.

  In addition, a Grignard reagent such as isopropyl magnesium chloride can be used together with the catalyst.

  Specific examples of the polymerization solvent include aprotic polarities such as N-methylpyrrolidone (NMP), tetrahydrofuran (THF), dimethylformamide (DMF), dimethyl sulfoxide (DMSO) and the like from the viewpoint of monomer solubility. A solvent is mentioned.

In Step 3, the protecting group of sulfonic acid in the obtained polymer is deprotected by a predetermined method depending on the kind of the protecting group.
The polymer electrolyte in this embodiment is obtained by the above procedure.

In the present embodiment, the molecular weight of the polymer electrolyte is not limited, but the weight average molecular weight Mw is, for example, 5 × 10 ³ or more, preferably 3 × 10 ⁴ or more. The method for measuring the molecular weight will be described later in the Examples section.
Further, IEC of the polymer electrolyte, for example 0.5 meq g ^-1 or more 4 meq g ^-1 or less, preferably 0.8 meq g ^-1 or more 3.3 meq g ^-1 or less.

The obtained polymer electrolyte is suitably used as a polymer electrolyte for a fuel cell, for example, as an inexpensive and low environmental impact hydrocarbon ionomer that replaces a fluorine ionomer.
The fuel cell in the present embodiment includes the polymer electrolyte in the present embodiment.

FIG. 1 is a cross-sectional view schematically showing the configuration of the fuel cell in the present embodiment.
A fuel cell 100 shown in FIG. 1 includes a membrane-electrode assembly (MEA) 115 including a fuel electrode (anode) 105, a solid electrolyte membrane 107, and an oxidant electrode (air electrode, cathode) 113. Have.
The fuel electrode 105 includes a diffusion layer 101 and a catalyst layer 103. The oxidant electrode 113 includes a diffusion layer 111 and a catalyst layer 109. A separator 117 and a separator 119 are disposed outside the diffusion layer 101 of the fuel electrode 105 and the diffusion layer 111 of the oxidant electrode 113, respectively, and these separators sandwich the membrane-electrolyte assembly 115.

The polymer electrolyte in the present embodiment is suitably used as an ionomer for a catalyst electrode, for example. Moreover, the catalyst electrode for fuel cells in this embodiment contains the polymer electrolyte in this embodiment.
More specifically, the polymer electrolyte in the present embodiment is suitably used for an ionomer of the catalyst layer 103 of the fuel electrode 105 or the catalyst layer 109 of the oxidant electrode 113. Among these, it is preferable to use the polymer electrolyte in the present embodiment for the catalyst layer 109 of the oxidant electrode 113 because gas (for example, oxygen, hydrogen) diffusibility in the oxidant electrode 113 can be improved.

In the fuel cell 100, for example, the following materials are used as the diffusion layer of each electrode, the catalyst, and the solid electrolyte membrane 107.
As the diffusion layer 101 and the diffusion layer 111, a porous material or the like is used, and examples thereof include carbon materials such as carbon paper and carbon nonwoven fabric.
For the catalyst layer 103 of the fuel electrode 105 and the catalyst layer 109 of the oxidant electrode 113, for example, carbon particles supporting a catalyst metal are used.
The type of catalyst at each electrode may be the same or different. Examples of the catalyst metal include noble metals such as platinum, gold, silver, palladium, rhodium, iridium, and ruthenium.
Examples of the material of the solid electrolyte membrane 107 include perfluorosulfonic acid polymers such as Nafion (registered trademark), Flemion (registered trademark), Aciplex (registered trademark), and Dow Membrane. Moreover, the solid electrolyte membrane 107 can also be comprised with the polymer electrolyte in this embodiment.

The fuel cell 100 is manufactured, for example, by the following method.
A catalyst is supported on carbon particles by a predetermined method such as an impregnation method to obtain a catalyst for each electrode (catalyst support). The obtained catalyst and polymer electrolyte are dispersed in a solvent and applied to the diffusion layer of each electrode to obtain the fuel electrode 105 and the oxidant electrode 113. At this time, the polymer electrolyte in the present embodiment can be used as the polymer electrolyte.
Then, the fuel electrode 105, the solid electrolyte membrane 107, and the oxidant electrode 113 are arranged in this order and joined together by thermocompression bonding or the like to obtain a membrane-electrolyte assembly 115.
Thereafter, separators for each electrode are disposed on both sides of the membrane-electrolyte assembly 115, and the fuel cell 100 shown in FIG. 1 is obtained.

There is no restriction | limiting in the use of the fuel cell 100, for example, vehicle-mounted use and household (cogeneration etc.) use are mentioned.
Moreover, there is no restriction | limiting in the kind of fuel and oxidant supplied to the fuel cell 100, For example, gaseous fuels, such as hydrogen; Liquid fuels, such as methanol, can be used as a fuel. The oxidizing agent can be air (oxygen), for example.

Next, the effect of this embodiment is demonstrated.
The polymer electrolyte in this embodiment is excellent in battery characteristics when used in a fuel cell because a flexible alkyl chain is introduced at a specific position of the side chain structure, and is suitable as a solid electrolyte for a fuel cell. Used for. Further, according to the present embodiment, for example, a polymer electrolyte having excellent gas permeability can be obtained, so that it can be used as a catalyst electrode of a fuel cell, more specifically as an ionomer of an oxidizer electrode.
Further, according to the present embodiment, for example, the output characteristics can be improved particularly under low humidification conditions, and therefore, it can be used as an excellent material in place of the fluorine-based ionomer. If PEFC can be operated with low humidification, it will lead to higher output and lower costs, and is expected to be a material that will accelerate the development of next-generation fuel cells.

（上記一般式（１）中、ユニット（Ａ）において、Ｒ ¹ は、独立して、水素原子、−Ｃ＝ＯＣ ₆ Ｈ ₃ Ｒ ³ Ｒ ⁴ 基または−ＯＲ ⁵ ＳＯ ₃ Ｈ基であり、ｍは１０以上の正の数である。ただし、２つのＲ ¹ のうち少なくとも１つは水素原子ではない。ユニット（Ｂ）において、Ｒ ² は、独立して、炭素数２以上６以下のアルキル基またはアルコキシ基であり、ｎは０または正の数である。
Ｒ ¹ が−Ｃ＝ＯＣ ₆ Ｈ ₃ Ｒ ³ Ｒ ⁴ 基であるとき、Ｒ ³ は、−Ｒ ³¹ −ＳＯ ₃ Ｈ基または−Ｒ ³² 基である。Ｒ ³¹ は炭素数２以上６以下のアルキレン基であり、Ｒ ³² は、炭素数２以上６以下のアルキル基である。Ｒ ⁴ は、水素原子または−ＳＯ ₃ Ｈ基である。ただし、Ｒ ⁴ が水素原子であるとき、Ｒ ³ は、−Ｒ ³¹ −ＳＯ ₃ Ｈ基である。
Ｒ ¹ が−ＯＲ ⁵ ＳＯ ₃ Ｈ基であるとき、Ｒ ⁵ は、−Ｒ ⁵¹ −Ｃ ₆ Ｈ ₄ −基または炭素数２以上６以下のアルキレン基であり、Ｒ ⁵¹ は、炭素数２以上６以下のアルキレン基であり、ｎは０でなく、ｍ個のユニット（Ａ）およびｎ個のユニット（Ｂ）がランダム共重合している。）
２． １．に記載の燃料電池用高分子電解質において、下記一般式（２）または（３）に示す構造を有する、燃料電池用高分子電解質。

（上記一般式（２）中、Ｒ ³¹ およびｍは、それぞれ、前記一般式（１）におけるＲ ³¹ およびｍに同じである。）

（上記一般式（３）中、Ｒ ³² およびｍは、それぞれ、前記一般式（１）におけるＲ ³² およびｍに同じである。）
３． １．に記載の燃料電池用高分子電解質において、下記一般式（４）に示す構造を有する、燃料電池用高分子電解質。

（上記一般式（４）中、Ｒ ² 、Ｒ ⁵ 、ｍおよびｎは、それぞれ、前記一般式（１）におけるＲ ² 、Ｒ ⁵ 、ｍおよびｎに同じである。）
４． １．乃至３．いずれか一つに記載の燃料電池用高分子電解質を含む、燃料電池用触媒電極。
５． ４．に記載の燃料電池用触媒電極を含む、燃料電池。
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention. .
Hereinafter, examples of the reference form will be added.
1. A polymer electrolyte for fuel cells having a structure represented by the following general formula (1).

(In the general formula (1), in the unit (A), R ¹ is independently a hydrogen atom, —C═OC ₆ H ₃ R ³ R ⁴ group or —OR ⁵ SO ₃ H group, m Is a positive number of 10 or more, provided that at least one of the two R ¹ is not a hydrogen atom, and in unit (B), R ² is independently an alkyl group having 2 to 6 carbon atoms. Or it is an alkoxy group, n is 0 or a positive number.
When R ¹ is a —C═OC ₆ H ₃ R ³ R ⁴ group, R ³ is a —R ³¹ —SO ₃ H group or a —R ³² group. R ³¹ is an alkylene group having 2 to 6 carbon atoms , and R ³² is an alkyl group having 2 to 6 carbon atoms. R ⁴ is a hydrogen atom or a —SO ₃ H group. However, when R ⁴ is a hydrogen atom, R ³ is a —R ³¹ —SO ₃ H group.
When R ¹ is an —OR ⁵ SO ₃ H group, R ⁵ is an —R ⁵¹ —C ₆ H ₄ — group or an alkylene group having 2 to 6 carbon atoms , and R ⁵¹ is 2 to 6 carbon atoms. The following alkylene groups, n is not 0, and m units (A) and n units (B) are randomly copolymerized. )
2. 1. The polymer electrolyte for fuel cells according to 1), wherein the polymer electrolyte for fuel cells has a structure represented by the following general formula (2) or (3).

(In the general formula (2), R ³¹ and m are the same as R ³¹ and m in the general formula (1), respectively .)

(In the general formula (3), R ³² and m are the same as R ³² and m in the general formula (1), respectively .)
3. 1. The polymer electrolyte for fuel cells described in 1 above, having a structure represented by the following general formula (4).

(In the general formula (4), R ² , R ⁵ , m and n are the same as R ² , R ⁵ , m and n in the general formula (1), respectively .)
4). 1. To 3. A catalyst electrode for a fuel cell comprising the polymer electrolyte for a fuel cell according to any one of the above.
5. 4). A fuel cell comprising the catalyst electrode for a fuel cell according to 1.

  In the following examples, the monomer compound or its precursor is identified by nuclear magnetic resonance (NMR) method, mass spectrometry (MS), elemental analysis, or infrared spectroscopy (IR). I did it.

In the following examples, the molecular weight of the polymer was measured using the following apparatus and conditions.
Equipment: Class-Vp system manufactured by Shimadzu Corporation
Column: Shodex KD-804, Shodex KD-805 (above, Showa Denko)
Solvent: THF
Standard: Polystyrene standard detection: Refractometer

Example 1
In this example, the following polymer: Poly (2- (4-ethyl-3-sulfobenzoyl) -1,4-phenylene) (S-PEtBP) was synthesized according to the procedures of Schemes 1 and 2.

Synthesis of (2,5-Dichlorophenyl) (4-ethyl-3- (neopentylsulfonyl) phenyl) methanone (NS-EtDBP) First, according to Scheme 1, a monomer NS-EtDBP was synthesized.

Synthesis of dichlorobenzene chloride (DCBC)
A 500 ml three-necked round bottom flask was charged with 50.4 g (0.264 mol) of 2,5-dichlorobenzoic acid (DCBA) and 200 ml of 1,2-dichloroethane, and fitted with a Dimroth condenser, a nitrogen inlet tube, and a dropping funnel. Further, an alkali trap and a calcium chloride pipe were attached to the cooling pipe, and the inside of the system was replaced with nitrogen. The solution was heated to 85 ° C. in an oil bath with stirring. After the solid in the flask was completely dissolved, 29.0 ml of thionyl chloride was gradually dropped from the dropping funnel. After completion of the dropwise addition, heating under reflux was continued for 2 hours. 1,2-Dichloroethane in the solution was distilled off using an evaporator. The yellowish brown residue was purified by distillation under reduced pressure to obtain a pale yellow transparent liquid DCBC (14 mmHg, 110 ° C., yield 47.7 g, yield 86%).

Synthesis of (2,5-Dichlorophenyl) (4-ethylphenyl) methanone (EtDBP) EtDBP was synthesized by the following procedure using the charging composition shown in Table 1.
A three-necked round bottom flask was equipped with a reflux condenser, a calcium chloride tube, a nitrogen inlet tube, and an alkali trap, and DCBC and ethylbenzene were added. Under a nitrogen atmosphere, aluminum chloride was added in several portions, heated to 75 ° C. in an oil bath and stirred for 3 hours. The obtained brown viscous liquid was developed in ice water, and then 100 mL of dichloromethane was added and stirred at room temperature for a while. The mixture was separated into a white turbid upper layer (aqueous layer) and a yellow transparent lower layer (organic layer), and the remaining aqueous layer was extracted with 1,2-dichloromethane. This was repeated three times, and then combined with the organic layer collected earlier. The obtained organic layer was washed three times in order of 10% by mass hydrochloric acid, aqueous sodium hydrogen carbonate solution and purified water, and dried over magnesium sulfate. Dichloromethane was distilled off with an evaporator and ethylbenzene was distilled off with a vacuum evaporator to obtain a crude product as a yellow transparent solid. Recrystallization was performed twice with methanol. Thereafter, the crystals were collected by suction filtration (membrane filter, hydrophilic, pore size 1.0 μm) and dried under reduced pressure at 45 ° C. for 24 hours to obtain white crystals. The yield and yield of the product are shown in Table 1. Moreover, the identification result by MS of a product is shown in FIG.

Synthesis of 5- (2,5-Dichlorobenzoyl) -2-ethylbenzene-1-sulfonyl chloride (SC-EtDBP) SC-EtDBP was synthesized by the following procedure using the charging composition shown in Table 2.
A 200 ml three-necked flask was equipped with a dropping funnel, reflux condenser, nitrogen inlet tube, calcium chloride tube, and alkali trap, and EtDBP was placed. Chlorosulfonic acid was dropped from the dropping funnel, and the mixture was stirred at 80 ° C. for 3 hours in an oil bath under a nitrogen atmosphere.
The resulting reddish brown solution was developed during 100 ml purification, then 100 ml dichloromethane was added and stirred for a while at room temperature. The mixture was separated into a cloudy upper layer (aqueous layer) and a skin-colored lower layer (organic layer), and the remaining aqueous layer was extracted with 1,2-dichloromethane. These operations were repeated three times, and then combined with the previously recovered organic layer. The obtained organic layer was washed with 5% aqueous sodium hydroxide and purified water in this order. Dichloromethane was removed by an evaporator and dried under reduced pressure at 40 ° C. for 24 hours to obtain SC-EtDBP. The yield and yield of the product are shown in Table 2.

Synthesis of (2,5-Dichlorophenyl) (4-ethyl-3- (neopentylsulfonyl) phenyl) methanone (NS-EtDBP)
A 200 ml three-necked flask was equipped with a dropping funnel, a calcium chloride tube, and a nitrogen introduction tube, and SC-EtDBP (5.79 g, 15.3 mmol) dissolved in chloroform was placed therein. Under a nitrogen atmosphere, pyridine and then a chloroform solution of 2,2-dimethyl-1-propanol (2.03 g, 23.0 mmol) were added to the solution, and the mixture was stirred at room temperature (25 ° C., the same applies hereinafter) for 20 hours. The obtained brown viscous liquid was washed with an aqueous ammonium sulfate solution and then washed with purified water, and chloroform was distilled off with an evaporator. The obtained pale yellow transparent viscous liquid was recrystallized twice with purified ethanol and dried under reduced pressure at 60 ° C. for 24 hours to obtain NS-EtDBP (3.12 g, 7.27 mmol) as white needle crystals (yield) 48%). Moreover, the identification result by MS of a product is shown in FIG.

  Polymerization was carried out by the procedure shown in Scheme 2 using NS-EtDBP obtained as described above as a monomer, to obtain S-PEtBP.

Synthesis of Poly (2- (4-ethyl-3- (neopentylsulfonyl) benzoyl) -1,4-phenylene (NS-PEtBP) A polymerization reaction is carried out according to the following procedure with the charge composition shown in Table 3, and NS-PEtBP is Obtained.
In a glove box under an argon atmosphere, a catalyst was prepared by putting NaI, PPh ₃ , Zn, NMP and nickel bis (triphenylphosphine) dichloride Ni (PPh ₃ ) ₂ Cl ₂ into a 50 ml three-necked flask. In addition, NS-EtDBP was dissolved in NMP, placed in a dropping funnel, and attached to a three-necked flask. The product was taken out from the glove box and stirred with a three-in-one motor at 40 ° C. in an argon atmosphere. After 15 minutes had passed since the catalyst solution turned deep red, the oil bath was raised to 65 ° C. and at the same time the monomer solution was added from the dropping funnel and stirred at high speed for 24 hours.
After completion of the reaction, the obtained dark red solid was stirred in 300 ml of methanol (30 ml of HCl) for 24 hours, and the solid was subjected to suction filtration (membrane filter, hydrophobic, pore size: 3.0 μm) and dried under reduced pressure at 50 ° C. for 24 hours. The obtained solid was dissolved in chloroform (5% by mass), and after suction filtration (Kiriyama filter paper 5A), it was reprecipitated in about 10 times the amount of methanol. The precipitate was collected and dried under reduced pressure at 50 ° C. Subsequently, NS-PEtBP as a white solid was obtained by drying under reduced pressure at 50 ° C. for 24 hours. The yield and yield of the product are shown in Table 3.

Synthesis of Poly (2- (4-ethyl-3-sulfobenzolyl) -1,4-phenylene) (S-PEtBP) Deprotection was carried out by the following procedure with the preparation composition shown in Table 4 to obtain S-PEtBP. .
A reflux condenser, a calcium chloride pipe, and a dropping funnel were attached to a 100 ml three-necked flask, and NS-PEtBP and purified NMP were added thereto, followed by stirring at 80 ° C. in a nitrogen atmosphere. After the solid was completely dissolved, an NMP solution of diethylamine hydrobromic acid was added dropwise from the dropping funnel, and the reaction solution was raised to 120 ° C. and stirred for 24 hours. After completion of the reaction, the resulting brown viscous solution was stirred in 300 ml of methanol (30 ml of HCl) for 24 hours. The obtained white solid was subjected to suction filtration (membrane filter, hydrophilic, pore size: 1.0 μm) and stirred in 1 mol dm ⁻³ HCl aqueous solution for 24 hours.

The liquid after stirring was administered into purified water, stirred with pH test paper until the filtrate became almost neutral, suction filtered (membrane filter, hydrophilic, pore size: 1.0 μm), and then dried under reduced pressure at 80 ° C. for 24 hours. The obtained brown solid was dissolved in NMP (10% by mass), subjected to suction filtration (Kiriyama filter paper 5A), and then reprecipitated into about 10 times the amount of diethyl ether. The precipitate was subjected to suction filtration (membrane filter, hydrophobic, pore size: 3.0 μm) and dried under reduced pressure at 80 ° C. for 24 hours to obtain brown solid S-PEtBP. The yield and yield of the product are shown in Table 4.
Moreover, the molecular weight of the obtained polymer was Mn = 57,400 and Mw = 155,000.

(Example 2)
In this example, the following polymer: Poly (2- (4-butyl-3-sulfobenzoyl) -1,4-phenylene) (S-PBuBP) was synthesized according to the procedures of Schemes 3 and 4.

(Synthesis of 4-Butyl-3- (neopentylsulfonyl) phenyl) (2,5-dichlorophenyl) methanone (NS-BuDBP))
First, according to Scheme 3, a monomer NS-BuDBP was synthesized.

Synthesis of (4-Butylphenyl) (2,5-dichlorophenyl) methanone (BuDBP)
DCBC (48.8 g, 233 mmol) synthesized by the method described in Example 1 and n-butylbenzene (32.2 g) were attached to a 300 ml three-necked round bottom flask equipped with a reflux condenser, a calcium chloride tube, a nitrogen inlet tube, and an alkali trap. 240 mmol). Under a nitrogen atmosphere, aluminum chloride (40.1 g, 301 mmol) was added in several portions, heated to 75 ° C. in an oil bath and stirred for 3 hours. The obtained brown viscous liquid was developed in ice water, chloroform was then added, and the mixture was stirred at room temperature for a while. The mixture was separated into a cloudy upper layer (aqueous layer) and a yellow transparent lower layer (organic layer), and the remaining aqueous layer was extracted with 100 ml of chloroform. This was repeated three times, and then combined with the organic layer collected earlier. The obtained organic layer was washed three times in the order of 10% by mass hydrochloric acid, aqueous sodium hydrogen carbonate solution and purified water, and dried over calcium chloride for 24 hours. Chloroform was distilled off with an evaporator, and butylbenzene was distilled off with a vacuum evaporator. The resulting yellow solid was recrystallized twice with purified body methanol and dried under reduced pressure at 40 ° C. for 24 hours to obtain BuDBP (38.2 g, 124 mmol) as a white solid (yield 53%). Moreover, the identification result by MS of a product is shown in FIG.

Synthesis of 2-Butyl-5- (2,5-dichlorobenzoyl) benzene-1-sulfonyl chloride (SC-BuDBP) SC-BuDBP was synthesized by the following procedure using the charging composition shown in Table 5.
A dropping funnel, a reflux condenser, a nitrogen inlet tube, a calcium chloride tube, and an alkali trap were attached to a 100 ml three-necked flask, and BuDBP was placed therein. The chlorosulfonic acid was dripped there from the dropping funnel, and it stirred with the oil bath in nitrogen atmosphere. After completion of the reaction, the resulting yellow-brown viscous liquid was developed in 100 ml of ice water and stirred on an ice bath.
The obtained white precipitate and the water tank were separated, and the aqueous layer was extracted with dichloroethane three times. The obtained organic layer and white precipitate were combined and washed with an aqueous sodium hydrogen carbonate solution and purified water in this order, and then dichloroethane was distilled off with an evaporator. The obtained white solid was subjected to suction filtration (membrane filter, hydrophobic, pore size 1.0 μm), and the crystals on the filter paper were washed with cooled n-hexane. This was dried under reduced pressure at 40 ° C. for 24 hours to obtain SC-BuDBP. The yield and yield of the product are shown in Table 5.

Synthesis of (4-Butyl-3- (neopentylsulfonyl) phenyl) (2,5-dichlorophenyl) methanone (NS-BuDBP) NS-BuDBP was synthesized by the following procedure using the charge composition shown in Table 6.
A 200-ml three-necked flask was equipped with a dropping funnel, a calcium chloride tube, and a nitrogen introduction tube, and SC-BuDBP dissolved in chloroform was placed therein. Under a nitrogen atmosphere, pyridine and then a chloroform solution of 2,2-dimethyl-1-propanol were added to this solution, followed by stirring at room temperature for 20 hours. The obtained brown viscous liquid was washed with an aqueous ammonium sulfate solution and then with purified water, and chloroform was distilled off with an evaporator. The obtained white solid was recrystallized twice with purified methanol and dried under reduced pressure at 45 ° C. for 24 hours to obtain needle-like NS-BuDBP. The yield and yield of the product are shown in Table 6. Moreover, the identification result by MS of a product is shown in FIG.

  Polymerization was performed according to the procedure shown in Scheme 4 using NS-BuDBP obtained as described above as a monomer to obtain S-PBuBP.

Synthesis of Poly (2- (4-butyl-3- (neopentylsulfonyl) benzoyl) -1,4-phenylene (NS-PBuBP) In a glove box under argon atmosphere, 0.037 g (0.25 mmol) of NaI in a 100 ml three-necked flask, PPh ₃ 0.209 g (0.798 mmol), Zn 0.193 g (2.96 mmol), and Ni (PPh ₃ ) ₂ Cl ₂ 0.039 g (0.060 mmol) were added to prepare the catalyst, and NS-BuDBP 0.913 g (1.99 mmol) Was dissolved in 1 ml of NMP, placed in a dropping funnel and attached to a three-necked flask, and after 2 ml of NMP was added to the catalyst, it was removed from the glove box and stirred with a three-in-one motor at 40 ° C. in an argon atmosphere. After changing to deep red, 15 minutes passed, the oil bath was raised to 65 ° C. and the monomer solution was added from the dropping funnel and stirred at high speed for 24 hours.
After completion of the reaction, the obtained dark red solid was stirred in 300 ml of methanol (30 ml of HCl) for 24 hours, and the solid was subjected to suction filtration (membrane filter, hydrophobic, pore size: 3.0 μm) and dried under reduced pressure at 50 ° C. for 24 hours. The obtained solid was dissolved in chloroform (5% by mass), and after suction filtration (Kiriyama filter paper 5A), it was reprecipitated in about 10 times the amount of methanol. The precipitate was collected and dried under reduced pressure at 50 ° C. The same operation was performed for reprecipitation and drying under reduced pressure, and drying under reduced pressure at 50 ° C. for 24 hours gave NS-PBuBP as a white solid (yield 0.342 g, yield 92%).

Synthesis of Poly (2- (4-butyl-3-sulfobenzoyl) -1,4-phenylene) (S-PBuBP)
A reflux condenser, a calcium chloride pipe, and a dropping funnel were attached to a 100 ml three-necked flask, and 1.40 g of NS-PBuBP and 7 ml of purified NMP were placed therein, followed by stirring at 80 ° C. in a nitrogen atmosphere. After the solid was completely dissolved, an NMP solution of diethylamine hydrobromic acid was added dropwise from the dropping funnel, and the reaction solution was raised to 120 ° C. and stirred for 24 hours. After completion of the reaction, the resulting brown viscous solution was stirred in 300 ml of methanol (30 ml of HCl) for 24 hours. The obtained white solid was subjected to suction filtration (membrane filter, hydrophilic, pore size: 1.0 μm), and stirred in 1 mol dm ⁻³ HCl aqueous solution at room temperature for 24 hours.
The liquid after stirring was administered into purified water, stirred with pH test paper until the filtrate became almost neutral, suction filtered (membrane filter, hydrophilic, pore size: 1.0 μm), and then dried under reduced pressure at 80 ° C. for 24 hours. The obtained brown solid was dissolved in NMP (10% by mass), subjected to suction filtration (Kiriyama filter paper 5A), and then reprecipitated in about 10 times the amount of diethyl ether. The precipitate was subjected to suction filtration (membrane filter, hydrophobic, pore size: 3.0 μm) and dried under reduced pressure at 80 ° C. for 24 hours to obtain brown solid S-PBuBP (yield 0.75 g, yield 54%).
Moreover, the molecular weight of the obtained polymer was Mn = 42,400 and Mw = 11,000.

(Example 3)
In this example, the following polymer: Poly (2- (4- (3-sulfopropyl) benzoyl-1,4-phenylene) (S-PrPBP)) was synthesized by the following procedure.

Synthesis of (4- (3-Bromopropyl) phenyl) (2,5-dichlorophenyl) methanone (BDCM) BDCM was synthesized by the procedure shown in Scheme 5.

  Under a nitrogen atmosphere, a Dimroth condenser, a calcium chloride pipe, and an alkali trap were attached to a three-necked flask. A nitrogen inlet tube and a dropping funnel were attached to the side tube of the three-necked flask, and 47.7 g (0.227 mol) of DCBC synthesized by the method described in Example 1 and 170 ml of dichloromethane were added, and 35.0 g (0.263 mol) of aluminum chloride was added. And stirred in ice water for 10 minutes. From the dropping funnel, 45.2 g (0.227 mol) of (3-bromopropyl) benzene (3-PPB) was slowly dropped and stirred for 4 hours. The solution became a brown solution. The reaction solution was developed in ice water containing 10% hydrochloric acid at a volume fraction and stirred for 1 hour. The solution became a white-yellow opaque solution. Ice water containing the reaction solution is put into a separatory funnel, the lower pink organic layer is extracted, washed once with 10% aqueous sodium hydroxide and 4 times with water, and the extracted organic layer is added with anhydrous magnesium sulfate. Dry for 24 hours. The solution became orange. Thereafter, dichloromethane was distilled off with an evaporator, and the obtained solid was purified twice by recrystallization to obtain a white transparent solid BDCM (yield 36.7 g, yield 43%). Moreover, the identification result by MS of a product is shown in FIG.

Synthesis of Sodium 3- (4- (2,5-dichlorobenzoyl) phenyl) propane-1-sulfonate (DPS-Na) DPS-Na was synthesized by the procedure shown in Scheme 6.

  To a 500 ml three-necked flask, 18.9 g (50.8 mmol) of BDCM, 180 ml of ethanol, and 75 ml of water were added. A stirrer chip was placed in the flask, and a Dimroth condenser tube with a nitrogen inlet tube was attached to the flask. Thereto was added 18.9 g (150 mmol) of sodium sulfite, and the system was heated to reflux at 100 ° C. for 48 hours under a nitrogen atmosphere. The solution gradually became white. Water and ethanol were distilled off from the reaction solution with an evaporator. The obtained white solid was transferred to a flask, hot water was added and heated in an oil bath, and the white solid was completely dissolved. Thereafter, it was subjected to hot filtration using Kiriyama filter paper (5A) and cooled to obtain a white solid. The obtained white solid was filtered through a membrane filter (hydrophilic, pore size: 1.0 μm) and then washed with water to obtain a white plate-like solid. Thereafter, recrystallization was performed using methanol / acetone (yield 12.8 g, yield 72%). Moreover, the identification result by MS of a product is shown in FIG.

Synthesis of 3- (4- (2,5-Dichlorobenzoyl) phenyl) propane-1-sulfonyl chloride (SC-PrDBP) SC-PrDBP was synthesized by the procedure shown in Scheme 7.

  A stirrer tip is placed in a 100 ml three-necked flask, a nitrogen inlet tube and a dropping funnel are attached to the side tube, a Dimroth condenser tube with a calcium chloride tube and an alkali trap is attached to the upper side, and DPS-Na 9.03 g (22.9 mmol) in a nitrogen atmosphere And 15 ml of DMF was added. After cooling in an ice bath, 9.01 g (75.5 mmol) of thionyl chloride was added from the dropping funnel, and stirring was continued at room temperature for 3 hours. The solution gradually suspended in yellow. The reaction solution was developed into a mixed solvent of 150 ml of dichloromethane and 100 ml of water, the organic layer was extracted, washed with an aqueous sodium hydrogen carbonate solution and water, and then the solvent was distilled off by an evaporator. The residual transparent pale yellow liquid was vacuum-dried to obtain a white plate-like solid (yield: 8.48 g, yield: 94%). Moreover, the identification result by MS of a product is shown in FIG.

Synthesis of (2,5-Dichlorophenyl) (4- (3- (neopentylsulfonyl) propyl) phenyl) methanone (NS-PrDBP) NS-PrDBP was synthesized by the procedure shown in Scheme 8.

  A stirrer tip is placed in a 100 ml three-necked flask, a nitrogen inlet tube and a dropping funnel are attached to the side tube, and a calcium chloride tube is attached to the upper side. Under a nitrogen atmosphere, 8.48 g (21.6 mmol) of SC-PrDBP is added, and 3.41 g of pyridine (43.1 mmol), 15 ml of dichloromethane were added. Thereto, 1.90 g (21.6 mmol) of neopentyl alcohol was dissolved in 10 ml of dichloromethane, added through a dropping funnel, and stirring was continued at room temperature for 20 hours. The solution gradually became a clear viscous liquid. The reaction solution was developed in chloroform, the organic layer was extracted, washed with an aqueous hydrochloric acid solution, an aqueous sodium hydrogen carbonate solution, and water, and then the solvent was distilled off with an evaporator. The obtained solid was filtered through a membrane filter (hydrophobic, pore size: 1.0 μm), washed with hexane, and dried under reduced pressure at 40 ° C. to obtain a white plate-like solid. Then, recrystallization was performed three times using 2-propanol / hexane to obtain NS-PrDBP as a transparent needle crystal (yield: 5.40 g, yield: 56%). Moreover, the identification result by MS of a product is shown in FIG.

Synthesis of Poly (2- (4- (3-neopentylsulfonyl) propyl) benzoyl-1,4-phenylene) (NS-PrPBP) Polymerization was performed using NS-PrDBP obtained as described above, and the procedure shown in Scheme 9 was performed. NS-PrPBP was synthesized.

In a glove box in an argon atmosphere, put nickel bis (triphenylphosphine) dichloride and triphenylphosphine, activated zinc powder and sodium iodide in the amounts shown in Table 7 in a 100 ml three-necked flask, add NMP, A catalyst solution was prepared.
Next, an NMP solution of NS-PrDBP was prepared in a 50 ml sample bottle and added to the dropping funnel attached to the side tube of the flask.
A vacuum sealer into which a stirring bar with Teflon (registered trademark) fins was inserted was attached to the top, and then removed from the glove box and stirred using a three-in-one motor at 40 ° C. for 15 minutes in an argon atmosphere. The color of the catalyst solution gradually changed to reddish brown, and then an NMP solution of NS-PrDBP was quickly dropped from the dropping funnel and stirred at 65 ° C. for 24 hours.
After completion of the reaction, the resulting dark black viscous material was added to a methanol / hydrochloric acid solution and stirred for 24 hours to remove the catalyst. The precipitate was filtered through a membrane filter (hydrophobic, pore size: 1.0 μm) and dried under reduced pressure at 50 ° C. to obtain a pale yellow solid crude NS-PrPBP. Further, it was dissolved in chloroform as a good solvent and reprecipitated in methanol as a poor solvent, and the precipitate was filtered and dried under reduced pressure. This operation was repeated twice to obtain white flocculent solid NS-PrPBP.
The amounts charged, yield and yield are as shown in Table 7.

Synthesis of Poly (2- (4- (3-sulfopropyl) benzoyl-1,4-phenylene) (S-PrPBP) S-PrDBP was synthesized by the procedure shown in Scheme 10.

NS-PrPBP is weighed into a 300 ml three-necked flask, a nitrogen inlet tube and a Dimroth condenser tube are connected to each side tube, NMP is added to it to make a nitrogen atmosphere, a vacuum sealer is attached, and a three in one motor is used at 300 rpm While stirring, the mixture was heated at 80 ° C. to completely dissolve the solid. Diethylamine hydrobromide was dissolved in NMP, added with a Pasteur, and heated and stirred at 120 ° C. for 24 hours. The solution gradually turned brown. Thereafter, the reaction solution was slowly added dropwise to a stirring methanol solution containing 10% hydrochloric acid, and stirring was continued at room temperature for 24 hours. The precipitate was collected with a membrane filter (hydrophobic, pore size 1.0 μm) and dried under reduced pressure at 50 ° C. to obtain a crude red-brown solid S-PrPBP. Further, the crudely purified solid was dissolved by heating in NMP and purified by reprecipitation in THF. The resulting precipitate was collected with a membrane filter (hydrophobic, pore size 3.0 μm) to obtain S-PrPBP.
The amounts charged, yield and yield are as shown in Table 8. In Table 8, the yield was calculated from the polymer weight, assuming that 100% deprotection was performed.
Moreover, the molecular weight of the obtained polymer was Mn = 65,000 and Mw = 213,000.

Example 4
In this example, a random copolymer Hr-SPr (also referred to as “SPr-rH” in this specification) was synthesized by the following procedure.

Preparation of Grignard monomers M1 and M3
The procedure for preparing Grignard monomers M1 and M3 is shown in Scheme 11. Table 9 shows the charged composition.

  1,4-dibromo-2,5-dihexyloxybenzene (DBHB) and 1,4-di [4- (2,2-dimetylpropoxysulfonyl) phenyl] propoxylbenzene (NS-) in a sun bottle under an argon atmosphere in a glove box DBPrB) was dissolved in THF, THF solution of isopropylmagnesium chloride lithiumchloride complex was added, and reacted at 40 ° C. for 5 hours to prepare 0.455M monomer solution.

  Using each monomer solution obtained, a polymerization reaction was carried out under the procedure shown in Scheme 12 and the conditions shown in Table 10.

In a flask placed under an argon atmosphere, Ni (dppe) Cl ₂ was dissolved in THF to prepare a catalyst solution. The prepared mixed solution of M1 and M3 monomer solution was added to the catalyst solution at room temperature and stirred for 30 hours. After stirring, the mixture was developed into a HCl aq./methanol mixed solution (1: 5, v / v) and stirred. The precipitate was suction filtered and dried under reduced pressure at 60 ° C. for 24 hours. The obtained solid was dissolved in chloroform and purified by reprecipitation into a methanol / acetone solution (1: 1, v / v).

Synthesis of Random Copolymer Hr-SPr The deprotection reaction was performed according to the procedure shown in Scheme 13 and the conditions shown in Table 11.

A polymer and NMP were placed in a three-necked flask equipped with a reflux condenser and stirred at 80 ° C. in a nitrogen atmosphere. After the solid was completely dissolved, the reaction solution was raised to 120 ° C. and an NMP solution of diethylaminehydrobromide was added dropwise and stirred for 48 hours. The brownish brown viscous solution was developed in diethyl ether and collected by suction filtration. The obtained reddish brown solid was stirred in 1M HCl aq. For 48 hours, then in purified water for 24 hours, recovered by suction filtration, and then dried under reduced pressure at 60 ° C. for 24 hours.
In the obtained polymer, m = 134 and n = 314.

(Example 5)
In this example, the solubility of S-PEtBP obtained in Example 1 and S-PBuBP obtained in Example 2 in various solvents was evaluated. The results are shown in Table 12 and Table 13, respectively. In Table 12 and Table 13, “x” indicates that the solvent was insoluble, and “◯” indicates that the solvent was soluble.
Up to now, there has been room for improvement in terms of workability at the time of processing such as solubility in a polyphenylene structure having a rigid skeleton.
On the other hand, in the S-PEtBP and S-PBuBP skeletons obtained in each Example, by introducing a flexible alkyl group into the side chain, as shown in Table 12 and Table 13, the solubility in organic solvents is Improved.

(Example 6)
In this example, the properties of the polymers obtained in the above examples as ionomers were evaluated.

(Measurement of hydrogen / oxygen gas permeability coefficient)
The gas permeability coefficient was measured about the polymer obtained in Examples 1-3 and the similar polymer (S-PPBP shown below) which has not introduce | transduced the alkyl group. The structure of the polymer used and the IEC determined by back titration method or elemental analysis method are shown below.

First, a sample film was formed for each polymer by the following method.
Each polymer was dissolved in a good solvent such as DMSO (5% by mass) and filtered. The solution was cast on a glass substrate, dried at 80 ° C. for 12 hours, and further dried at 80 ° C. for 3 hours under reduced pressure. After peeling from the substrate, it was washed with 1 mol / l HCl aqueous solution and purified water, and then dried under reduced pressure at 65 ° C. for 24 hours.

Using a GTR-20XFMD (GTR Tech) apparatus, a flow type gas / water vapor permeability measuring device with a gas chromatograph G2700T (manufactured by Yanaco) installed in a cell with a sample film molded into a 3.5 x 3.5 cm square Measurements were made. Oxygen and hydrogen gas were supplied at a rate of 30 ml min ⁻¹ , and the gas permeability coefficient (P) was determined from the amount of oxygen and hydrogen permeated through the membrane at 80 ° C. and relative humidity of 0 to 90%. Argon and helium were used as carrier gases for hydrogen and oxygen, respectively.
The measurement conditions are as follows.
Measurement temperature: 80 ℃
Measurement humidity: 0-90% RH
Hydrogen gas supply amount: 30ml min ^-1
Oxygen gas supply: 30ml min ^-1
The results are shown in FIG.

  In addition, with respect to the random copolymer obtained in Example 4 and Nafion 112 (manufactured by DuPont), the production of the membrane and gas permeability were evaluated by methods similar to the above. The results are shown in FIG.

10 and 11, all of the polymer electrolytes obtained in Examples 1 to 4 were excellent in gas permeability. Moreover, from FIG. 11, the polymer electrolyte obtained in Example 4 showed high gas permeability exceeding Nafion 112.
Therefore, any of the polymer electrolytes obtained in each example can be suitably used as, for example, an ionomer for a catalyst electrode of a fuel cell.

(Evaluation of power generation characteristics)
An MEA was produced according to the following procedure, and its power generation characteristics were evaluated.
Using the polymer electrolyte or Nafion obtained in each Example as the ionomer of the catalyst electrode, an MEA was produced by the following procedure. Table 14 shows the composition of the catalyst and ionomer used in the preparation of the catalyst electrode and the solvent used.

Using the raw materials shown in Table 14, a catalyst ink was prepared so that the ionomer solution was 5% by mass. The solvent was a single solvent or a mixed solvent in which 5% by mass of water was added to alcohol. The amounts of ionomer material and platinum in the MEA were both about 1.0 mg cm ⁻² .
Platinum-supported carbon (Pt / C, Tanaka Kikinzoku Co., Ltd.) was weighed into a sample bottle and water was added slightly. The mixture was stirred for 2 minutes at 50 ° C. using a stirrer and degassed for 1 minute to fully adjust the catalyst to water. Next, the ionomer solution was dropped into a sample bottle, and a catalyst ink was prepared by stirring for 3 hours using a stirrer as before. The prepared catalyst ink was applied to carbon paper (manufactured by SGL Carbon Co., Ltd.) with a microspatel and dried with a heat stirrer. Thereafter, the carbon paper was dried under reduced pressure at 80 ° C. for 3 hours, sandwiched between Kapton and a stainless steel plate at 130 ° C. and 100 kgcm ⁻² for 10 minutes, and subjected to surface treatment by hot pressing.
Next, the electrolyte membrane (Nafion 211 membrane) was sandwiched between Kapton and a stainless steel plate at 130 ° C. and 100 kgcm ⁻² for 10 minutes so as to be sandwiched between the catalyst-coated surfaces of the catalyst electrode and hot-pressed.

About the obtained MEA, the voltage generated using FUEL CELL TEST SYSTEM SERIES 890B (manufactured by Toyo Technica) was measured, and the following was performed using a fuel cell evaluation device (model PEM-8900-18, manufactured by Toyo Technica) Evaluation was performed under conditions.
Measurement conditions Cell temperature: 80 ℃
Anode / cathode temperature: 80 ° C to 53 ° C (100% RH to 30% RH)
Anode gas: H ₂
Anode gas supply flow rate: 0.5L min ^-1
Cathode gas: Synthetic air (containing 20% oxygen)
Cathode gas supply flow rate: 1.0 L min ^-1
Anode / cathode supply gas back pressure: 0.1 MPaG

12 to 14 show the results of S-PEtBP obtained in Example 1, S-PBuBP obtained in Example 2, and S-PrPBP obtained in Example 3 as ionomers of catalyst electrodes, respectively. FIG. FIG. 15 is a diagram showing the results of SPr-rH obtained in Example 4.
FIG. 16 is a diagram showing the humidity dependence of the output density at 80 ° C. of MEA using the polymer electrolyte obtained in Examples 1 to 3 and Nafion as the ionomer of the catalyst electrode.

From FIG. 12 to FIG. 15, MEA using the polymer electrolyte obtained in Examples 1 to 4 as the ionomer of the catalyst electrode has an excellent balance of cell voltage, power density and cell resistance characteristics, and has low humidity. The characteristic deterioration under the above conditions was effectively suppressed.
Moreover, it can be seen from FIG. 16 that by using the ionomers of Examples 1 to 3, excellent output characteristics superior to Nafion can be obtained under low humidity conditions.

DESCRIPTION OF SYMBOLS 100 Fuel cell 101 Diffusion layer 103 Catalyst layer 105 Fuel electrode 107 Solid electrolyte membrane 109 Catalyst layer 111 Diffusion layer 113 Oxidant electrode 115 Membrane-electrolyte assembly 117 Separator 119 Separator

Claims (4)

A polymer electrolyte for a fuel cell having a structure represented by the following general formula (2) or (3).

(In the general formula (2), R ³¹ is an alkylene group having 2 to 6 carbon atoms, and m is a positive number of 10 or more.)

(In the general formula (3), R ³² is an alkyl group having 2 to 6 carbon atoms, and m is the same as m in the general formula (2).) A polymer electrolyte for fuel cells having a structure represented by the following general formula (4).

(In the above general formula (4), R ² is independently an alkyl group or alkoxy group having 2 to 6 carbon atoms, and R ⁵ is an —R ⁵¹ —C ₆ H ₄ — group or 2 carbon atoms. An alkylene group having 6 or less and R ⁵¹ is an alkylene group having 2 to 6 carbon atoms, m is a positive number of 10 or more, n is a positive number, and m units (A) and n units (B) are copolymerized, provided that, in the above general formula (4), R ⁵ is an alkylene group having 4 carbon atoms, and R ² is an alkoxy having 4 carbon atoms. Excluding what is the base.))   A fuel cell catalyst electrode comprising the fuel cell polymer electrolyte according to claim 1.   A fuel cell comprising the fuel cell catalyst electrode according to claim 3.

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