Polysilane derivatives having sulfonic acid groups and polymer electrolyte fuel cells

Abstract

The present invention provides a compound having both hydrophilic and hydrophobic parts, which, when used as an electrolyte in the catalyst layer of a polymer electrolyte fuel cell, enables the polymer electrolyte fuel cell to exhibit good power generation characteristics while suppressing voltage drop in the high current density range. [Solution] The compound is represented by formula (I). TIFF2026051908000013.tif59161 (In the formula, R 1 and R 2 Each of these is independently a substituted / unsubstituted aromatic group or a substituted / unsubstituted alkyl group, A is a direct bond, a substituted / unsubstituted aromatic group, a substituted / unsubstituted alkyl group, or a combination thereof, x is 0.1 to 0.8, y is 0.2 to 0.9, x + y = 1, and n is 1 to 3.

Description

[Technical Field]

[0001] The present invention relates to a polysilane derivative having a sulfonic acid group and a polymer electrolyte fuel cell using the derivative. [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 Initiative] [Problems that the invention aims to solve]

[0004] Fluorine-based ionomers have problems such as being difficult and costly to dispose of. On the other hand, fuel cells have a problem in that water is generated during power generation, and this generated water accumulates in the electrode catalyst layer and gas diffusion layer, which hinders the supply of oxygen on the cathode side, resulting in a fluttering phenomenon in which power generation characteristics decrease in the high current density range. Under these circumstances, there is a need for the development of hydrocarbon-based ionomers that possess both hydrophobic and hydrophilic parts, in order to achieve power generation characteristics comparable to or better than conventional fluorine-based ionomers, while also suppressing the fluttering phenomenon.

[0005] The present invention aims to provide a compound having both hydrophilic and hydrophobic parts, which, when used as an electrolyte in the catalyst layer of a polymer electrolyte fuel cell, enables the polymer electrolyte fuel cell to exhibit good power generation characteristics while suppressing voltage drop in the high current density range. [Means for solving the problem]

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

[14] . [1] A compound having a structure represented by the following general formula (I). [ka] (In general formula (I), R 1 and R 2 Each of these is independently an optionally substituted aromatic group or an optionally substituted alkyl group, A is a direct bond, an optionally substituted aromatic group, an optionally substituted alkyl group, or a combination thereof, x is 0.1 to 0.8, y is 0.2 to 0.9, x + y = 1, and n is 1 to 3. [2] A compound of [1] in which A is an aromatic group in general formula (I). [3] The compound of [1] which has the structure represented by the following general formula (Ia). [ka] (In general formula (Ia), R 1 , R2 、x, y, and n are the same as those in the general formula (I).) [4] In the general formula (I), R 1 and R 2 are each independently a phenyl group which may have a substituent or an alkyl group having 1 to 3 carbon atoms which may have a substituent, the compound of [1]. [5] A method for producing the compound represented by the general formula (I), comprising polymerizing a polysilane compound (a) represented by the following reaction formula and a vinyl compound (b) having a sulfonic acid group protected by esterification, and then deprotecting the sulfonic acid group of the obtained polymer (c). [Chemical formula] (In the above reaction formula, R 1 , R 2 , A, x, y, and n are the same as those in the general formula (I), and R 3 is an alkyl group which may have a substituent or a cycloalkyl group which may have a substituent.) [6] A catalyst composition comprising a compound of any one of [1] to [4], a catalyst, and a catalyst carrier. [7] The catalyst composition of [6] for a solid polymer fuel cell. [8] A catalyst layer of a solid polymer fuel cell comprising the catalyst composition of [6]. [9] A membrane electrode assembly having a solid electrolyte membrane, a gas diffusion layer, and the catalyst layer of [8].

[10] A solid polymer fuel cell having the membrane electrode assembly of [9].

[11] The compounds of [1] to [4] used as an electrolyte for the anode catalyst layer and / or the cathode catalyst layer of a solid polymer fuel cell.

[12] A catalyst layer of a solid polymer fuel cell comprising any one of the compounds of [I] to [4].

[13] A solid electrolyte membrane comprising any one of the compounds of [1] to [4].

[14] A solid polymer fuel cell having the solid electrolyte membrane of

[13] . [Advantages of the Invention]

[0007] <I The compound of the present invention possesses both hydrophilic and hydrophobic parts, and when used as an electrolyte in the catalyst layer of a polymer electrolyte fuel cell, it enables the polymer electrolyte fuel cell to exhibit good power generation characteristics while suppressing voltage drop in the high current density range. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic cross-sectional view showing the structure of a polymer electrolyte fuel cell. [Figure 2] This figure shows the power generation characteristics of the polymer electrolyte fuel cell fabricated in the example when the relative humidity on both the fuel electrode and air electrode sides is 50%RH. [Modes for carrying out the invention]

[0009] A compound having the structure represented by the following general formula (I). [ka] (In general formula (I), R 1 and R 2 Each of these is independently an optionally substituted aromatic group or an optionally substituted alkyl group, A is a direct bond, an optionally substituted aromatic group, an optionally substituted alkyl group, or a combination thereof, x is 0.1 to 0.8, y is 0.2 to 0.9, x + y = 1, and n is 1 to 3. The general formula (I) is as follows:

[0010] R 1 and R 2 Each of these is independently an optionally substituted aromatic group or an optionally substituted alkyl group, preferably an optionally substituted phenyl group or an optionally substituted C1-C3 alkyl group, and more preferably a phenyl group or an optionally substituted C1 alkyl group.

[0011] Examples of substituents include halogens, alkyl groups, haloalkyl groups, and alkoxy groups.

[0012] R 1 and R 2 Of the combinations, the combination of a methyl group and a phenyl group, and the combination of two phenyl groups are particularly preferred.

[0013] A is a direct bond, an optionally substituted aromatic group, an optionally substituted alkyl group, or a combination thereof, preferably a direct bond, an optionally substituted aromatic group, or an optionally substituted alkyl group, more preferably an aromatic group, and even more preferably a phenyl group.

[0014] x is between 0.1 and 0.8, and preferably between 0.4 and 0.6. y is between 0.2 and 0.9, and preferably between 0.4 and 0.6. x + y = 1. n is between 1 and 3.

[0015] In a compound having a structure represented by general formula (I), the structure in which A is a phenyl group is represented by the following general formula (Ia). [ka]

[0016] In general formula (Ia), the sulfonic acid group is not particularly limited in its position relative to the bonded position of the phenyl group in the main chain, but it is preferably at least in the para position.

[0017] In general formula (Ia), R 1 , R 2 x, y, and n are the same as in general formula (I).

[0018] Compounds (I) and (Ia) described above are suitably used as hydrocarbon ionomers, as will be discussed later. In this specification, ionomer refers to a polymer material having proton-conducting properties. Hydrocarbon ionomer refers to an ionomer whose basic skeleton is a hydrocarbon, and may optionally contain heteroatoms and halogen atoms. This is a concept distinct from fluorinated sulfonic acid polymers whose main chain consists of fluorine-substituted hydrocarbons, although the main chain may have halogens as substituents.

[0019] [Method for producing compounds] Compounds of general formula (I) are produced by the following manufacturing method. [ka]

[0020] In the above reaction equation, R 1 , R 2 A, x, y, and n are the same as in general formula (I). 3 The alkyl group is optionally substituted or optionally substituted, and preferably it is an alkyl group having 1 to 3 carbon atoms or an optionally substituted cycloalkyl group having 6 to 15 carbon atoms. Examples of substituents include halogens, alkyl groups, haloalkyl groups, and alkoxy groups.

[0021] First, the vinyl compound containing a sulfonic acid group is esterified to protect the sulfonic acid group. Next, the polysilane compound (a) and the vinyl compound (b) having a sulfonic acid group protected by esterification are photopolymerized. Finally, the obtained polymer (c) is heated in water to deprotect the sulfonic acid group and obtain the compound represented by general formula (I).

[0022] [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.

[0023] 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 a fuel cell. It is preferable to use it in the anode catalyst layer 103 and the cathode catalyst layer 105 of the fuel cell, and it is more preferable to use it in at least the cathode catalyst layer 105 from the viewpoint of suppressing the rise in overvoltage caused by the decrease in oxygen gas diffusivity during high-current driving. The compound represented by the general formula (I) has a polysilane portion that is hydrophobic and a sulfonic acid group that is hydrophilic, and can achieve good power generation characteristics while suppressing the fluttering phenomenon.

[0024] 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.

[0025] 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 or known nonmetal catalyst can be used without particular limitation, and as the catalyst in the cathode catalyst layer 105, any known metal catalyst can be used without particular limitation. 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. Examples of nonmetal catalysts include carbon alloy catalysts.

[0026] Carbon alloy catalysts are carbon materials obtained by heating and carbonizing raw materials containing organic materials and metals, and are known to exhibit catalytic activity. The organic material can be any material that can be carbonized without particular restrictions, but examples include thermosetting resins such as melamine resin, epoxy resin, and phenolic resin. The metal can be any known metal without particular restrictions, but examples include iron, cobalt, and titanium.

[0027] 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.

[0028] 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.

[0029] 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 catalyst, and a catalyst support is prepared as a catalyst ink, and then the catalyst ink is applied to a target substrate and dried to produce a catalyst layer. The catalyst composition may contain, as an electrolyte, the compound represented by the general formula (I) or an electrolyte other than the compound represented by the general formula (I).

[0030] Examples of suitable substrates include polymer electrolyte membranes, GDL, and sheets made of fluororesin, and a catalyst layer can be produced by known manufacturing methods. When a catalyst ink is applied to a sheet made of fluororesin, the applied catalyst layer is transferred to a polymer electrolyte membrane. When using a substrate made of fluororesin, it is preferable to include the steps of applying the catalyst composition to the substrate made of fluororesin and drying the applied catalyst composition to obtain a catalyst layer which is then transferred to a solid electrolyte membrane. Examples of fluororesins include polytetrafluoroethylene (PTFE), PFA (perfluoroalkoxyalkane), EFTE (ethylenetetrafluoroethylene copolymer), FEP (perfluoroethylenepropene copolymer), PVDF (polyvinylidene fluoride), PCTFE (polychlorotrifluoroethylene), ECTFE (ethylenechlorotrifluoroethylene copolymer), etc., with polytetrafluoroethylene (PTFE) being preferred. Here, fluororesin refers to a resin containing fluorine atoms.

[0031] The compound represented by the general formula (I) can coat the 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 catalyst is preferably 0.1 to 10 times.

[0032] 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.

[0033] 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.

[0034] 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 solids content excluding the weight of the solvent, the 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.

[0035] 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.

[0036] 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.

[0037] 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. [Examples]

[0038] 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. [Method for measuring number-average molecular weight (Mn)] 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)

[0039] <Example 1> [Synthesis of Ionomer 1] [ka]

[0040] (1) Synthesis of P-1 Under a nitrogen atmosphere, 4.0 g of M-1, 20 g of M-2, and 50 mL of tetrahydrofuran were added to a container, and nitrogen was bubbled in for 30 minutes to prepare the reaction solution. The prepared reaction solution was placed in a reaction vessel, cooled to 0°C, and exposed to a nitrogen atmosphere at an illumination of 8 mW / cm². 2 Under a high-pressure mercury lamp, the exposure dose was 135 J / cm². 2 The mixture was stirred under exposure until the reaction was complete. The reaction mixture was added dropwise to methanol and stirred. The mixture was filtered, and the resulting filtrate was dried to obtain 4.1 g of the target P-1. Mn 3100 (PDI 1.5) 1 H NMR(400MHz,CDCl3)δ(ppm):6.20-7.90(11.5H,Ph),3.95-4.30(2H,-O-CH2-),1.05-2.10(3H,CH and CH2),1.05-1.41(3H,-CH3),0.05(4.5H,Si-CH3)

[0041] (2) Synthesis of Ionomer 1 2.5 g of P-1 and 20 mL of water were placed in a reaction vessel and stirred under reflux conditions for 12 hours. The reaction mixture was concentrated and dried to obtain 2.1 g of the target ionomer 1 (yield 80%). Mn 3100 (PDI 1.5) 1 H NMR(400MHz,DMSO-d6)δ(ppm):6.10-7.80(11.5H), 1.05-2.10(3H,CH and CH2), 0.05(4.5H,Si-CH3)

[0042] <Example 2> [Synthesis of Ionomer 2] [ka]

[0043] (1) Synthesis of P-2 Except for setting the input ratios of M-1 and M-2 to 1.0g and 10g, respectively, the synthesis was carried out in the same procedure as for the synthesis of P-1 in Example 1 to obtain the target P-2. Mn 2300 (PDI 2.0)

[0044] (2) Synthesis of Ionomer 2 Except for using P-2 as a raw material, the target ionomer 2 was obtained using the same procedure as the synthesis of ionomer 1 in Example 1. Mn 2300 (PDI 2.0)

[0045] <Test Example 1> [Preparation of catalytic ink] 0.15 g of platinum-supported carbon catalyst (TEC10E50E, manufactured by Tanaka Kikinzoku Kogyo Co., Ltd.) and a 1% water / 1-propanol (1 wt / 1 wt) solution of ionomer 2 synthesized in Example 2 were added to a glass container, and the mixture was ultrasonically irradiated with a homogenizer for 20 minutes to prepare a catalyst ink.

[0046] [Fabrication of gas diffusion electrodes] A gas diffusion layer with a microporous layer (SIGRACET GDL28BC, made of SGL carbon) is placed on a hot plate at 80°C, and the catalyst ink prepared using the above method is sprayed onto the microporous layer side until the basis weight of the platinum catalyst is 0.1 mg / cm³. 2 A gas diffusion electrode was fabricated by coating it and forming a catalyst layer on a microporous layer in such a manner.

[0047] [Fabrication of membrane-electrode junctions] A pair of gas diffusion electrodes, fabricated as described above, were placed on both sides of an electrolyte membrane (Nafion NR212, 50 μm thickness, manufactured by Chemours), and a membrane-electrode assembly was fabricated by hot pressing under conditions of 0.47 kN and 140°C for 10 minutes.

[0048] [Evaluation of power generation] A polymer electrolyte fuel cell was fabricated by covering the membrane-electrode assembly obtained above with a pair of gaskets, except for the electrode portion, and arranging separators that 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 air electrode supplied with air, and the other side as the fuel electrode supplied with hydrogen to generate electricity. The power generation conditions were set to a cell temperature of 80°C, and the relative humidity on both the fuel electrode and air electrode sides to 50%RH. Power generation evaluation was performed by supplying gas to each electrode, and an IV curve was obtained. The results are shown in Figure 2.

[0049] <Example of comparative test> [Preparation of catalytic ink] In a glass container, 0.2 g of platinum-supported carbon catalyst (TEC10E50E, manufactured by Tanaka Kikinzoku Kogyo), 3.9 g of deionized water, 3.9 g of 1-propanol, and a 5% Nafion solution (Nafion DE520 CS type, manufactured by Fujifilm Wako) were added, and the mixture was ultrasonically irradiated with a homogenizer for 20 minutes to prepare a catalyst ink.

[0050] [Fabrication of gas diffusion electrodes] A gas diffusion electrode was fabricated using the same procedure as in Test Example 1.

[0051] [Fabrication of membrane-electrode junctions] A membrane-electrode junction was fabricated using the same procedure as in Test Example 1.

[0052] [Evaluation of power generation] The power generation evaluation was performed using the same procedure as in Test Example 1, and an IV curve was obtained.

[0053] Figure 2 shows the results when the relative humidity on both the fuel electrode and air electrode sides was set to 50%RH.

[0054] From Figure 2, when the relative humidity on both the fuel electrode and air electrode sides is 50%RH, the current density is 0.4 A / cm². 2 In the above domains, Test Example 1, using Ionomer 2 in the Examples, exhibits superior power generation characteristics compared to the comparative test example using Nafion. [Explanation of symbols]

[0055] 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 9】 (In general formula (I), R １ and R ２ Each of these is independently an optionally substituted aromatic group or an optionally substituted alkyl group, A is a direct bond, an optionally substituted aromatic group, an optionally substituted alkyl group, or a combination thereof, x is 0.1 to 0.8, y is 0.2 to 0.9, x + y = 1, and n is 1 to 3.

2. The compound according to claim 1, wherein A is an aromatic group in general formula (I).

3. The compound according to claim 1, wherein the compound has a structure represented by the following general formula (Ia). 【Chemistry 10】 (In general formula (Ia), R １ , R ２ , x, y, and n are the same as in the general formula (I) above.

4. In the above general formula (I), R １ and R ２ The compound according to claim 1, wherein each of them is independently a phenyl group which may have a substituent or an alkyl group having 1 to 3 carbon atoms which may have a substituent.

5. A method for producing the compound represented by the general formula (I), comprising polymerizing a polysilane compound (a) represented by the following reaction equation with a vinyl compound (b) having a sulfonic acid group protected by esterification, and then deprotecting the sulfonic acid group of the resulting polymer (c). 【Chemistry 11】 (In the above reaction formula, R １ , R ２ , A, x, y, and n are the same as those in the general formula (I), and R ３ is an alkyl group which may have a substituent or a cycloalkyl group which may have a substituent.)

6. A catalyst composition comprising the compound, catalyst, and catalyst support according to any one of claims 1 to 4.

7. The catalyst composition according to claim 6, for use in polymer electrolyte fuel cells.

8. A catalyst layer for a polymer electrolyte fuel cell comprising the catalyst composition described in claim 6.

9. A membrane electrode assembly having a solid electrolyte membrane, a gas diffusion layer, and the catalyst layer described in claim 8.

10. A polymer electrolyte fuel cell having the membrane electrode assembly described in claim 9.

11. A compound according to any one of claims 1 to 4, used as an electrolyte for the anode catalyst layer and / or cathode catalyst layer of a polymer electrolyte fuel cell.

12. A catalyst layer for a polymer electrolyte fuel cell comprising the compound described in any one of claims 1 to 4.

13. A solid electrolyte membrane comprising the compound described in any one of claims 1 to 4.

14. A polymer electrolyte fuel cell having a solid electrolyte membrane as described in claim 13.

Images