JP2004186142A - Electrode structure for solid polymer fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrode structure for a solid polymer fuel cell which has excellent generating performance and durability, a solid polymer fuel cell equipped with the electrode structure, and an electrical equipment and a transport equipment using the solid polymer fuel cell. <P>SOLUTION: The electrode structure comprises a pair of electrode catalyst layers 1 containing carbon particles that carries platinum particles and a polyelectrolyte membrane 2 made of sulfonated polyarylene polymer that is interposed by both electrode catalyst layers. The sulfonated polyarylene polymer has an ion exchange capacity in the range of 1.7-2.3 meq/g, and the insoluble component content of this polymer to N-methylpyrrolidone, after applying heat treatment of exposing for 200 hours in the constant temperature of 120°C, is 70 wt% or less to the total amount of the polymer. Sulfonated polyarylene polymer is a sulfonated product of a copolymer as expressed by a specific chemical formula or a copolymer as expressed by a specific chemical formula. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to an electrode structure used for a polymer electrolyte fuel cell.

  While petroleum resources are being depleted, environmental problems such as global warming due to consumption of fossil fuels are becoming more serious. In view of this, fuel cells have attracted attention as clean electric power sources for electric motors that do not generate carbon dioxide, and have been widely developed, and some have begun to be put into practical use. When the fuel cell is mounted on an automobile or the like, a solid polymer fuel cell using a polymer electrolyte membrane is preferably used because a high voltage and a large current are easily obtained.

  As the electrode structure used in the polymer electrolyte fuel cell, a pair of electrode catalysts formed by a catalyst such as platinum supported on a catalyst carrier such as carbon black and integrated with an ion-conductive polymer binder There is known a structure in which an ion-conductive polymer electrolyte membrane is sandwiched between both electrode catalyst layers and a diffusion layer is laminated on each electrode catalyst layer (for example, see Patent Document 1). ). In the electrode structure, a polymer electrolyte fuel cell can be formed by further laminating a separator also serving as a gas passage on each diffusion layer.

  In the polymer electrolyte fuel cell, a reducing gas such as hydrogen or methanol is introduced through the diffusion layer using one electrode catalyst layer as a fuel electrode, and the other electrode catalyst layer is introduced through the diffusion layer as an oxygen electrode. Oxidizing gas such as air and oxygen. With this configuration, on the fuel electrode side, protons are generated from the reducing gas by the action of the catalyst contained in the electrode catalyst layer, and the protons pass through the polymer electrolyte membrane to the electrode on the oxygen electrode side. Move to the catalyst layer. Then, the protons react with the oxidizing gas introduced into the oxygen electrode in the electrode catalyst layer on the oxygen electrode side by the action of a catalyst contained in the electrode catalyst layer to generate water. Therefore, a current can be taken out by connecting the fuel electrode and the oxygen electrode with a conducting wire.

  Conventionally, in the electrode structure, a perfluoroalkylenesulfonic acid polymer compound (for example, Nafion (trade name) manufactured by DuPont) has been widely used as the polymer electrolyte membrane. The perfluoroalkylene sulfonic acid polymer compound has excellent proton conductivity by being sulfonated, and also has chemical resistance as a fluororesin, but is very expensive. There is.

  Therefore, it has been studied to construct an electrode structure for a polymer electrolyte fuel cell by using an inexpensive ion conductive material instead of a perfluoroalkylenesulfonic acid polymer compound. As the inexpensive ion conductive material, for example, a sulfonated polyarylene-based polymer is known.

However, in the electrode structure using the polymer electrolyte membrane made of the sulfonated polyarylene-based polymer, when the fuel cell is constructed, the polymer electrolyte membrane deteriorates due to heat during operation, and the fuel electrode side and oxygen There are inconveniences that gases introduced on the pole side may be mixed, or that a cross leak may occur which causes an electrical short circuit.
JP 2000-223136 A

  An object of the present invention is to provide an electrode structure for a polymer electrolyte fuel cell having excellent power generation performance and excellent durability against heat during operation of the fuel cell, by solving such disadvantages.

  The polyarylene-based polymer can be given an ion-exchange ability by being sulfonated, and the greater the number of sulfonic acid groups introduced into the polymer, the greater the ion-exchange capacity, but the larger the amount of sulfonic acid groups introduced, The greater the number of sulfonic acid groups, the more easily they are deteriorated by heating.

  The present inventors have studied the sulfonated polyarylene-based polymer, and found that when the number of sulfonic acid groups introduced is large, the sulfonated polyarylene-based polymer has an It has been found that a crosslinking reaction occurs, and a component insoluble in a solvent such as N-methylpyrrolidone is generated. The present inventors have further studied based on the above findings, the amount of the component insoluble in the solvent contained in the sulfonated polyarylene-based polymer, the polymer electrolyte membrane comprising the sulfonated polyarylene-based polymer The inventors have found that the toughness of the fuel cell is affected, and that the decrease in toughness is related to the power generation performance of the fuel cell and the durability to heat during operation of the fuel cell.

  Therefore, the electrode structure for a polymer electrolyte fuel cell of the present invention, in order to achieve such an object, a pair of electrode catalyst layers containing carbon particles carrying platinum particles as a catalyst, and both electrode catalyst layers In the electrode structure for a polymer electrolyte fuel cell comprising the sandwiched polymer electrolyte membrane, the polymer electrolyte membrane is made of a sulfonated polyarylene-based polymer, and the sulfonated polyarylene-based polymer is 1.7 After having been subjected to a heat treatment of exposing for 200 hours under a constant temperature atmosphere of 120 ° C., the content of the polymer insoluble component with respect to N-methylpyrrolidone was determined to be the total amount of the polymer. 70% by weight or less.

  The content of the insoluble component was determined by gel permeation chromatography, and the elution curves of an untreated polymer electrolyte membrane and a polymer electrolyte membrane after subjected to a treatment of exposing to a constant temperature atmosphere of 120 ° C. for 200 hours were measured. Then, it can be calculated from the area ratio of the elution curve (the area of the elution curve of the untreated polymer electrolyte membrane is set to 100).

  According to the electrode structure for a polymer electrolyte fuel cell of the present invention, the sulfonated polyarylene-based polymer has an ion exchange capacity in the above range, and after the heat treatment, N-methylpyrrolidone of the polymer When the content of the insoluble component is within the above range, excellent power generation performance and excellent durability against heat during operation of the fuel cell can be obtained.

  In addition, in this specification, a "sulfonated polyarylene-based polymer" means a sulfonated product of a polymer having the following formula.

前記２価の有機基としては、−ＣＯ−、−ＣＯＮＨ−、−（ＣＦ_２）_ｐ−（ｐは１〜１０の整数）、−Ｃ（ＣＦ_３）_２−、−ＣＯＯ−、−ＳＯ−、−ＳＯ_２−等の電子吸引性基、−Ｏ−、−Ｓ−、−ＣＨ＝ＣＨ−、−Ｃ≡Ｃ−等の基、さらに次式で表される電子供与性基等を挙げることができる。

Examples of the divalent organic group, -CO -, - CONH -, - (CF 2) p - (p is an integer of from 1 to _{10), - C (CF 3)} 2 -, - COO -, - SO- , -SO ₂ - electron-withdrawing group such as, -O -, - S -, - CH = CH -, - C≡C- such groups further include an electron-donating groups represented by the following formula Can be.

また、前記２価の電子吸引性基としては、−ＣＯ−、−ＣＯＮＨ−、−（ＣＦ_２）_ｐ−（ｐは１〜１０の整数）、−Ｃ（ＣＦ_３）_２−、−ＣＯＯ−、−ＳＯ−、−ＳＯ_２−等の基を挙げることができる。

Further, as the divalent electron attractive group, -CO -, - CONH -, - (CF 2) p - (p is an integer of from 1 to _{10), - C (CF 3)} 2 -, - COO- , -SO -, - SO ₂ - group and the like.

  When the ion exchange capacity of the sulfonated polyarylene-based polymer is less than 1.7 meq / g, the electrode structure for a polymer electrolyte fuel cell of the present invention cannot obtain sufficient power generation performance. Further, the ion-exchange capacity of the sulfonated polyarylene-based polymer exceeds 2.3 meq / g, and the content of the polymer insoluble component to N-methylpyrrolidone after the heat treatment is 70% by weight of the total amount of the polymer. %, Sufficient durability against heat during fuel cell operation cannot be obtained.

  In the polymer electrolyte fuel cell electrode structure of the present invention, when the ion exchange capacity is in the above range, the content of the insoluble component after the heat treatment is in the above range. The arylene polymer is preferably, for example, a sulfonated product of the copolymer represented by the formula (1) or a copolymer represented by the formula (2).

また、本発明は、前記固体高分子型燃料電池用電極構造体を備える固体高分子型燃料電池にもある。本発明の固体高分子型燃料電池は、例えば、パーソナルコンピュータ、携帯電話等の電気機器の電源、バックアップ電源等として用いることができる。また、本発明の固体高分子型燃料電池は、例えば、自動車、潜水艦等の船舶等の輸送用機器の動力等としても用いることができる。

The present invention also resides in a polymer electrolyte fuel cell including the polymer electrolyte fuel cell electrode structure. The polymer electrolyte fuel cell of the present invention can be used, for example, as a power supply, a backup power supply, and the like for electric devices such as personal computers and mobile phones. Further, the polymer electrolyte fuel cell of the present invention can be used, for example, as a power source for transportation equipment such as automobiles and submarines.

  Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 is an explanatory cross-sectional view showing one configuration example of the electrode structure of the present embodiment.

  As shown in FIG. 1, the electrode structure of the present embodiment includes a pair of electrode catalyst layers 1, 1, a polymer electrolyte membrane 2 sandwiched between the two electrode catalyst layers 1, 1, and each electrode catalyst layer 1, 1. 1 and diffusion layers 3 and 3 stacked on top of each other.

  The electrode catalyst layer 1 is composed of catalyst particles in which platinum particles are supported on carbon particles, and an ion conductive binder. As the ion conductive binder, a polymer electrolyte such as the perfluoroalkylenesulfonic acid polymer compound (for example, Nafion (trade name) manufactured by DuPont), a sulfonated polyarylene-based polymer, or the like is used.

  The polymer electrolyte membrane 2 is made of a sulfonated polyarylene-based polymer, and the sulfonated polyarylene-based polymer has an ion exchange capacity in a range of 1.7 to 2.3 meq / g. Further, the content of the insoluble component in N-methylpyrrolidone of the sulfonated polyarylene-based polymer after subjecting to a heat treatment of exposing to a constant temperature atmosphere of 120 ° C. for 200 hours is 70% by weight of the total amount of the polymer. The following are used:

  When the ion exchange capacity is in the above range, the sulfonated polyarylene-based polymer in which the content of the insoluble component after the heat treatment is in the above range is, for example, a copolymer represented by Formula (1). Or a copolymer represented by the formula (2).

式（１）で表される共重合体は、次式（３）で表されるモノマーと、次式（４）で表されるオリゴマーとを共重合させることにより得ることができる。

The copolymer represented by the formula (1) can be obtained by copolymerizing a monomer represented by the following formula (3) and an oligomer represented by the following formula (4).

式（１）で表される共重合体は、さらに濃硫酸と反応させることによりスルホン化して、電子吸引性基に隣接していないベンゼン環にスルホン酸基を導入してスルホン化することができる。

The copolymer represented by the formula (1) can be sulfonated by further reacting with concentrated sulfuric acid, and sulfonated by introducing a sulfonic acid group into a benzene ring not adjacent to the electron-withdrawing group. .

Further, the copolymer represented by the formula (2) is obtained by copolymerizing a monomer represented by the following formula (5) and an oligomer represented by the formula (4), and then a sulfonic acid ester group ( —SO ₃ CH (CH ₃ ) C ₂ H ₅ ) to obtain a sulfonic acid group (—SO ₃ H) by hydrolysis.

前記拡散層３は、例えばカーボンペーパーと、該カーボンペーパー上に形成された図示しない下地層とからなる。前記下地層は、例えば、カーボンブラックと、ポリテトラフルオロエチレン粒子との４：６（重量比）の混合物が用いられる。

The diffusion layer 3 includes, for example, carbon paper and a base layer (not shown) formed on the carbon paper. For the underlayer, for example, a mixture of carbon black and polytetrafluoroethylene particles in a ratio of 4: 6 (weight ratio) is used.

  In the electrode structure of the present embodiment, a reducing gas such as hydrogen or methanol is introduced into the electrode catalyst layer 1 via the diffusion layer 3 on the fuel electrode (anode) side, while the diffusion layer 3 on the oxygen electrode (cathode) side is introduced. When an oxidizing gas such as air or oxygen is introduced into the electrode catalyst layer 1 through the electrode, protons and electrons are generated from the reducing gas on the fuel electrode side by the action of the catalyst contained in the catalyst layer 1. The protons move to the catalyst layer 1 on the oxygen electrode side via the polymer electrolyte membrane 2, and the oxidizing gas and the electrons introduced into the catalyst layer 1 by the action of the catalyst contained in the catalyst layer 1. Reacts with to produce water. Therefore, by connecting the fuel electrode and the oxygen electrode via a conducting wire, a circuit for sending electrons generated at the fuel electrode to the oxygen electrode is formed, a current can be taken out, and the electrode structure is It can be used as a battery.

  Next, examples of the present invention and comparative examples will be described.

  In this example, first, 2,2-bis (4-hydroxyphenyl) -1,2 was placed in a 1-liter three-necked flask equipped with a stirrer, thermometer, cooling tube, Dean-Stark tube, and three-way cock for introducing nitrogen. 67.3 g (0.20 mol) of 1,1,3,3,3-hexafluoropropane (bisphenol AF), 53.5 g (0.214 mol) of 4,4′-dichlorobenzophenone, 34.6 g of potassium carbonate ( 0.251 mol), 300 ml of N, N-dimethylacetamide and 150 ml of toluene were taken, heated in an oil bath under a nitrogen atmosphere, and reacted at 130 ° C. with stirring. When water produced by the reaction was azeotroped with toluene and reacted while being removed from the system with a Dean-Stark tube, almost no water was observed in about 3 hours. Therefore, most of the toluene was removed while gradually increasing the reaction temperature from 130 ° C to 150 ° C. After the reaction was continued at 150 ° C. for 10 hours, 3.3 g (0.0133 mol) of 4,4′-dichlorobenzophenone was added, and the reaction was further performed for 5 hours.

  After allowing the obtained reaction solution to cool, the precipitate of by-product inorganic compound was removed by filtration, and the filtrate was poured into 4 liters of methanol. The precipitated product was separated by filtration, recovered, dried, and then dissolved in 300 ml of tetrahydrofuran. This was reprecipitated with 4 liters of methanol to obtain 98 g of an oligomer represented by the following formula (4) (yield: 93%).

次に、式（４）で表されるオリゴマー２８．４ｇ（２．８７ミリモル）、２，５−ジクロロ−４’−（４−フェノキシ）フェノキシベンゾフェノン２９．２ｇ（６７．１ミリモル）、ビス（トリフェニルホスフィン）ニッケルジクロリド１．３７ｇ（２．１ミリモル）、ヨウ化ナトリウム１．３６ｇ（９．０７ミリモル）、トリフェニルホスフィン７．３４ｇ（２８．０ミリモル）、亜鉛末１１．０重量部（１６８ミリモル）をフラスコに取り、乾燥窒素置換した。次に、Ｎ−メチル−２−ピロリドン１３０ｍｌを加え、８０℃に加熱して撹拌下に４時間重合を行った。重合溶液をテトラヒドロフランで希釈し、塩酸／メタノールで凝固させ回収した。回収物に対してメタノール洗浄を繰り返し、テトラヒドロフランに溶解した。これをメタノールで再沈殿して精製し、濾集したポリマーを真空乾燥して、式（１）で表されるポリアリーレン系ポリマー５．０７ｇを得た（収率９６％）。

Next, 28.4 g (2.87 mmol) of the oligomer represented by the formula (4), 29.2 g (67.1 mmol) of 2,5-dichloro-4 ′-(4-phenoxy) phenoxybenzophenone, bis ( 1.37 g (2.1 mmol) of triphenylphosphine) nickel dichloride, 1.36 g (9.07 mmol) of sodium iodide, 7.34 g (28.0 mmol) of triphenylphosphine, 11.0 parts by weight of zinc dust ( 168 mmol) was placed in a flask and purged with dry nitrogen. Next, 130 ml of N-methyl-2-pyrrolidone was added, and the mixture was heated to 80 ° C. and polymerized for 4 hours with stirring. The polymerization solution was diluted with tetrahydrofuran and solidified and recovered with hydrochloric acid / methanol. The collected product was repeatedly washed with methanol and dissolved in tetrahydrofuran. This was purified by reprecipitation with methanol, and the polymer collected by filtration was vacuum-dried to obtain 5.07 g of a polyarylene-based polymer represented by the formula (1) (96% yield).

次に、式（１）で表されるポリアリーレン系ポリマーに濃硫酸を加え、イオン交換容量が１．７ｍｅｑ／ｇとなるようにスルホン化して、スルホン化ポリアリーレン系ポリマーを調製した。

Next, concentrated sulfuric acid was added to the polyarylene polymer represented by the formula (1), and sulfonated so that the ion exchange capacity became 1.7 meq / g, to prepare a sulfonated polyarylene polymer.

  Next, a polymer electrolyte solution was prepared by dissolving the sulfonated polyarylene polymer in N-methylpyrrolidone, and a polymer electrolyte membrane 2 having a dry film thickness of 35 μm was prepared from the polymer electrolyte solution by a casting method. .

  Next, catalyst particles were prepared by supporting platinum particles on carbon black (furnace black) at a weight ratio of platinum particles: carbon black = 1: 1. Next, the catalyst particles are added to a solution of a perfluoroalkylenesulfonic acid polymer compound (for example, Nafion (trade name) manufactured by DuPont) as an ion-conductive polymer binder solution. = 5: 7 to obtain a catalyst paste.

  Next, a slurry obtained by mixing carbon black and polytetrafluoroethylene (PTFE) particles at a weight ratio of 4: 6 and uniformly dispersed in ethylene glycol is applied to one surface of carbon paper, and dried. Thus, a base layer was formed, and a diffusion layer 3 composed of the carbon paper and the base layer was formed.

Next, the above-mentioned catalyst paste was applied onto the underlayer of the diffusion layer 3 so that the amount of platinum was 0.5 mg / cm ² , heated at 60 ° C. for 10 minutes, and then heated at 120 ° C. under reduced pressure for 60 minutes. Then, the catalyst layer 1 was formed by drying.

  Next, the polymer electrolyte membrane 2 was sandwiched between the catalyst layers 1 and 1, and integrated by performing hot pressing at 150 ° C. and 2.5 MPa for 1 minute to produce the electrode structure shown in FIG.

  Next, the content of the insoluble component of the polyarylene polymer in the polymer electrolyte membrane 2 obtained in the present example was measured, and the power generation performance of the electrode structure obtained in the present example was evaluated.

  The insoluble component content of the polyarylene-based polymer was measured by subjecting the polymer electrolyte membrane 2 to a heat treatment of exposing the polymer electrolyte membrane 2 to a constant temperature atmosphere of 120 ° C. for 200 hours, and then performing gel permeation chromatography on the untreated polymer electrolyte membrane. 2 and the elution curve of the polymer electrolyte membrane 2 after the heat treatment. The insoluble component content of the polyarylene-based polymer was calculated from the area ratio of the elution curve, with the area of the elution curve of the untreated polymer electrolyte membrane 2 as 100.

  The gel permeation chromatograph was measured by HLC-8020 (trade name) manufactured by Tosoh Corporation using a differential refractive index detector. As columns, two Shodex KD-806M (trade name) manufactured by Showa Denko KK were used, and one Shodex KD-G (trade name) manufactured by Showa Denko KK was used as a precolumn. The solvent used was N-methylpyrrolidone (primary reagent, containing 50 mmol / l lithium chloride and 50 mmol / l phosphoric acid) at a flow rate of 1.0 ml / min. The temperature was set to 40 ° C. for all of the column, inlet, and detector. The sample was filtered through a 0.5 μm polytetrafluoroethylene filter to a concentration of 0.3% by weight and an injection amount of 0.3 ml.

  As a result, in the polymer electrolyte membrane 2 obtained in this example, the content of the insoluble component of the polyarylene-based polymer was 15% by weight.

Next, using the electrode structure obtained in this example, the power generation performance was evaluated under the power generation conditions of a temperature of 95 ° C., a relative humidity of 35% on the fuel electrode side, and a relative humidity of 65% on the oxygen electrode side. Table 1 shows the results. The power generation performance was measured by measuring the cell potential at a current density of 0.5 A / cm ² , and if the cell potential was 0.4 V or more, the result was indicated as “」 ”in Table 1 as good and less than 0.4 V In this case, it was indicated as bad in Table 1 by "x".

  In addition, when power generation was performed under the above conditions, the durable time until cross leak occurred on the fuel electrode side and the oxygen electrode side was measured. The results are shown in Table 1.

  Example 1 In this example, a polyarylene-based polymer represented by the formula (1) was sulfonated so as to have an ion exchange capacity of 2.0 meq / g to prepare a sulfonated polyarylene-based polymer. The electrode structure shown in FIG.

  Next, the content of the insoluble component to N-methylpyrrolidone of the polyarylene-based polymer in the polymer electrolyte membrane 2 obtained in this example was measured in the same manner as in Example 1. In the polymer electrolyte membrane 2 obtained in this example, the content of the insoluble component in the polyarylene-based polymer was 35% by weight.

  Next, using the electrode structure obtained in this example, the power generation performance was evaluated in the same manner as in Example 1, and the endurance time was measured. Table 1 shows the results.

  In this example, the polyarylene-based polymer represented by the formula (1) was sulfonated so as to have an ion exchange capacity of 2.3 meq / g to prepare a sulfonated polyarylene-based polymer. The electrode structure shown in FIG. 1 was manufactured in exactly the same manner as in Example 1.

  Next, the content of the insoluble component to N-methylpyrrolidone of the polyarylene-based polymer in the polymer electrolyte membrane 2 obtained in this example was measured in the same manner as in Example 1. In the polymer electrolyte membrane 2 obtained in this example, the content of the insoluble component in the polyarylene-based polymer was 56% by weight.

  Next, using the electrode structure obtained in this example, the power generation performance was evaluated in the same manner as in Example 1, and the endurance time was measured. Table 1 shows the results.

[Comparative Example 1]
In this comparative example, the polyarylene-based polymer represented by the formula (1) was sulfonated so as to have an ion exchange capacity of 1.5 meq / g to prepare a sulfonated polyarylene-based polymer. The electrode structure shown in FIG. 1 was manufactured in exactly the same manner as in Example 1.

  Next, the content of the insoluble component in N-methylpyrrolidone of the polyarylene-based polymer in the polymer electrolyte membrane 2 obtained in this comparative example was measured in the same manner as in Example 1. In the polymer electrolyte membrane 2 obtained in this comparative example, the content of the insoluble component of the polyarylene-based polymer was 0.

  Next, using the electrode structure obtained in this comparative example, power generation performance was evaluated in exactly the same manner as in Example 1. In this comparative example, since the power generation performance was poor, the durability time was not measured. Table 1 shows the results.

[Comparative Example 2]
In this comparative example, the polyarylene-based polymer represented by the formula (1) was sulfonated so as to have an ion exchange capacity of 2.4 meq / g to prepare a sulfonated polyarylene-based polymer. The electrode structure shown in FIG. 1 was manufactured in exactly the same manner as in Example 1.

  Next, the content of the insoluble component in N-methylpyrrolidone of the polyarylene-based polymer in the polymer electrolyte membrane 2 obtained in this comparative example was measured in the same manner as in Example 1. In the polymer electrolyte membrane 2 obtained in this comparative example, the content of the insoluble component of the polyarylene-based polymer was 75% by weight.

  Next, using the electrode structure obtained in this comparative example, the power generation performance was evaluated in the same manner as in Example 1, and the endurance time was measured. Table 1 shows the results.

[Comparative Example 3]
In this comparative example, the polyarylene-based polymer represented by the formula (1) was sulfonated so that the ion-exchange capacity became 2.5 meq / g to prepare a sulfonated polyarylene-based polymer. The electrode structure shown in FIG. 1 was manufactured in exactly the same manner as in Example 1.

  Next, the content of the insoluble component in N-methylpyrrolidone of the polyarylene-based polymer in the polymer electrolyte membrane 2 obtained in this comparative example was measured in the same manner as in Example 1. In the polymer electrolyte membrane 2 obtained in this comparative example, the content of the insoluble component in the polyarylene-based polymer was 78% by weight.

  Next, using the electrode structure obtained in this comparative example, the power generation performance was evaluated in the same manner as in Example 1, and the durability time was measured. Table 1 shows the results.

表１から、イオン交換容量が１．７ｍｅｑ／ｇ未満の場合（比較例１）には、十分な発電性能が得られないことが明らかである。これに対して、イオン交換容量が１．７ｍｅｑ／ｇ以上の場合には優れた発電性能が得られることが明らかである。

From Table 1, it is clear that when the ion exchange capacity is less than 1.7 meq / g (Comparative Example 1), sufficient power generation performance cannot be obtained. In contrast, when the ion exchange capacity is 1.7 meq / g or more, it is apparent that excellent power generation performance can be obtained.

  Further, when the ion exchange capacity is in the range of 1.7 to 2.3 meq / g and the content of the insoluble component is 70% by weight or less (Examples 1 to 3), the ion exchange capacity is 2.3 meq. / G and the insoluble content exceeds 70% by weight (Comparative Example 2 and Comparative Example 3). It is evident that it has excellent durability against heat.

FIG. 2 is an explanatory cross-sectional view showing one configuration example of the electrode structure of the present invention.

Explanation of reference numerals

  1. Electrode catalyst layer 2. Polymer electrolyte membrane 3. Diffusion layer

Claims (6)

In a polymer electrolyte fuel cell electrode structure including a pair of electrode catalyst layers containing carbon particles carrying platinum particles as a catalyst and a polymer electrolyte membrane sandwiched between both electrode catalyst layers,
The polymer electrolyte membrane is made of a sulfonated polyarylene-based polymer,
The sulfonated polyarylene-based polymer has an ion exchange capacity in the range of 1.7 to 2.3 meq / g, and after being subjected to a heat treatment of exposing to a constant temperature atmosphere of 120 ° C. for 200 hours, the N- An electrode structure for a polymer electrolyte fuel cell, wherein the content of an insoluble component with respect to methylpyrrolidone is 70% by weight or less of the total amount of the polymer. The electrode structure for a polymer electrolyte fuel cell according to claim 1, wherein the sulfonated polyarylene-based polymer is a sulfonated product of a copolymer represented by the formula (1).

The electrode structure for a polymer electrolyte fuel cell according to claim 1, wherein the sulfonated polyarylene-based polymer is a copolymer represented by the formula (2).

A pair of electrode catalyst layers containing carbon particles carrying platinum particles as a catalyst, and a polymer electrolyte membrane sandwiched between both electrode catalyst layers,
The polymer electrolyte membrane is made of a sulfonated polyarylene-based polymer,
The sulfonated polyarylene-based polymer has an ion exchange capacity in the range of 1.7 to 2.3 meq / g, and after being subjected to a heat treatment of exposing to a constant temperature atmosphere of 120 ° C. for 200 hours, the N- A polymer electrolyte fuel cell comprising a polymer electrolyte fuel cell electrode structure having a content of an insoluble component to methylpyrrolidone of 70% by weight or less of the total amount of the polymer. A pair of electrode catalyst layers containing carbon particles carrying platinum particles as a catalyst, and a polymer electrolyte membrane sandwiched between both electrode catalyst layers,
The polymer electrolyte membrane is made of a sulfonated polyarylene-based polymer,
The sulfonated polyarylene-based polymer has an ion exchange capacity in the range of 1.7 to 2.3 meq / g, and after being subjected to a heat treatment of exposing to a constant temperature atmosphere of 120 ° C. for 200 hours, the N- An electric device comprising a polymer electrolyte fuel cell provided with a polymer electrolyte fuel cell electrode structure having a content of insoluble components to methylpyrrolidone of not more than 70% by weight of the total amount of the polymer. A pair of electrode catalyst layers containing carbon particles carrying platinum particles as a catalyst, and a polymer electrolyte membrane sandwiched between both electrode catalyst layers,
The polymer electrolyte membrane is made of a sulfonated polyarylene-based polymer,
The sulfonated polyarylene-based polymer has an ion exchange capacity in the range of 1.7 to 2.3 meq / g, and after being subjected to a heat treatment of exposing to a constant temperature atmosphere of 120 ° C. for 200 hours, the N- A transport equipment characterized by using a polymer electrolyte fuel cell having a polymer electrolyte fuel cell electrode structure in which the content of an insoluble component to methylpyrrolidone is 70% by weight or less of the total amount of the polymer.

Images