JP3407320B2 - Polymer electrolyte fuel cell - Google Patents
Polymer electrolyte fuel cellInfo
- Publication number
- JP3407320B2 JP3407320B2 JP34592892A JP34592892A JP3407320B2 JP 3407320 B2 JP3407320 B2 JP 3407320B2 JP 34592892 A JP34592892 A JP 34592892A JP 34592892 A JP34592892 A JP 34592892A JP 3407320 B2 JP3407320 B2 JP 3407320B2
- Authority
- JP
- Japan
- Prior art keywords
- carbon
- fine powder
- catalyst
- fuel cell
- surface area
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 239000000446 fuel Substances 0.000 title claims description 24
- 239000005518 polymer electrolyte Substances 0.000 title description 11
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 60
- 229910052799 carbon Inorganic materials 0.000 claims description 46
- 239000000843 powder Substances 0.000 claims description 46
- 239000003054 catalyst Substances 0.000 claims description 39
- 239000011148 porous material Substances 0.000 claims description 24
- 229910000510 noble metal Inorganic materials 0.000 claims description 18
- 229920000642 polymer Polymers 0.000 claims description 8
- 239000000203 mixture Substances 0.000 claims description 4
- 239000005871 repellent Substances 0.000 claims description 3
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 claims description 2
- 239000003456 ion exchange resin Substances 0.000 claims description 2
- 229920003303 ion-exchange polymer Polymers 0.000 claims description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 20
- 230000000052 comparative effect Effects 0.000 description 15
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 12
- 229910052697 platinum Inorganic materials 0.000 description 10
- 239000002923 metal particle Substances 0.000 description 8
- 239000002245 particle Substances 0.000 description 8
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 7
- 239000012535 impurity Substances 0.000 description 7
- 239000011593 sulfur Substances 0.000 description 7
- 229910052717 sulfur Inorganic materials 0.000 description 7
- 239000000460 chlorine Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 239000007787 solid Substances 0.000 description 6
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 5
- 239000006230 acetylene black Substances 0.000 description 5
- 239000006229 carbon black Substances 0.000 description 5
- 229910052801 chlorine Inorganic materials 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 231100000572 poisoning Toxicity 0.000 description 5
- 230000000607 poisoning effect Effects 0.000 description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 239000006185 dispersion Substances 0.000 description 4
- 238000009826 distribution Methods 0.000 description 4
- 239000003014 ion exchange membrane Substances 0.000 description 4
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 description 3
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 239000010970 precious metal Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000010419 fine particle Substances 0.000 description 2
- 239000007800 oxidant agent Substances 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 229920000557 Nafion® Polymers 0.000 description 1
- DWAQJAXMDSEUJJ-UHFFFAOYSA-M Sodium bisulfite Chemical compound [Na+].OS([O-])=O DWAQJAXMDSEUJJ-UHFFFAOYSA-M 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 239000003610 charcoal Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000000084 colloidal system Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 238000003411 electrode reaction Methods 0.000 description 1
- -1 for example Substances 0.000 description 1
- 239000002803 fossil fuel Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000007731 hot pressing Methods 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- MUMZUERVLWJKNR-UHFFFAOYSA-N oxoplatinum Chemical compound [Pt]=O MUMZUERVLWJKNR-UHFFFAOYSA-N 0.000 description 1
- 229910003446 platinum oxide Inorganic materials 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 235000010267 sodium hydrogen sulphite Nutrition 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 238000004876 x-ray fluorescence Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/90—Selection of catalytic material
- H01M4/92—Metals of platinum group
- H01M4/925—Metals of platinum group supported on carriers, e.g. powder carriers
- H01M4/926—Metals of platinum group supported on carriers, e.g. powder carriers on carbon or graphite
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/90—Selection of catalytic material
- H01M4/92—Metals of platinum group
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/10—Fuel cells with solid electrolytes
- H01M8/1004—Fuel cells with solid electrolytes characterised by membrane-electrode assemblies [MEA]
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0065—Solid electrolytes
- H01M2300/0082—Organic polymers
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Description
【発明の詳細な説明】
【０００１】
【産業上の利用分野】本発明は燃料として純水素、また
はメタノールや化石燃料からの改質水素などの還元剤を
用い、空気や酸素を酸化剤とする固体高分子型燃料電池
に関するものである。
【０００２】
【従来の技術】固体高分子型燃料電池は作動温度が６０
〜１５０℃と低いため、電極には高活性な貴金属触媒、
とくに白金触媒が用いられている。その特性向上にはそ
の電極に用いる貴金属触媒の形態及びその分散状態が関
与するところが大きく、特に炭素微粉末上に高活性な貴
金属粒子を高分散な状態で担持させることが重要な技術
とされる。従って貴金属触媒の担持方法に関しても多く
の研究がなされている。例えば、貴金属粒子を高分散の
状態で炭素微粉末上に担持させるために担体である炭素
微粉末の三次元構造を破壊し、貴金属粒子の吸着サイト
を増加させる方法が提案されていた（特開昭６３−３１
９０５０号公報）。また、固体高分子型燃料電池と同じ
く低温で作動し、貴金属触媒を用いるメタノール燃料電
池用のメタノール酸化触媒については、２０〜４０Åの
貴金属のコロイド粒子を調製し、そのコロイド粒子を市
販の５０〜３００ｍ2／ｇの比表面積を持つ炭素微粉末
上に沈着させる方法（特開昭６３−９７２３２号公報）
や、担体となる炭素微粉末の細孔分布や比表面積に関す
る報告がされていた（特開平３−１０１０５７号公
報）。
【０００３】
【発明が解決しようとする課題】このような従来の貴金
属触媒では、固体高分子型燃料電池用触媒としての担体
となる炭素微粉末に関する検討が十分にされておらず、
炭素微粉末の種類によって貴金属粒子の分散状態が異な
り、十分な放電特性が得られていないという欠点を有し
ていた。また、担体となる炭素微粉末に触媒被毒物質で
ある塩素や硫黄などの不純物が含まれるために十分な寿
命特性が得られていないという欠点を有していた。
【０００４】本発明は上記従来の問題点を解決するもの
で、貴金属触媒の担体となる炭素微粉末の細孔分布、比
表面積などの最適条件をみつけだし、かつ不純物の含有
量が少ない炭素微粉末を用いることによって、高い放電
特性を示し、しかも寿命特性の優れた固体高分子型燃料
電池を提供することを目的とする。
【０００５】
【課題を解決するための手段】この課題を解決するため
本発明の固体高分子型燃料電池は、直径２５〜７０Åの
細孔の占める容積が全細孔容積の３０．１％以上であ
り、かつ比表面積が８００ｍ２／ｇ以上の炭素微粉末に
高分散された貴金属からなる触媒と、撥水化処理した炭
素微粉末との混合物層を導電性カーボンペーパー上に形
成し、前記混合物層の表面にイオン交換樹脂を塗布した
電極を用いたことを特徴とする。
【０００６】
【作用】この構成によって、炭素微粉末の直径２５〜７
０Åの細孔が直径１０〜３０Åの触媒貴金属粒子の吸着
核となり、炭素微粉末上の反応に有効なサイトに高活性
な貴金属粒子を微粒子状態のまま担持させることができ
る。さらに、上記の範囲の細孔径を持ち、比表面積が８
００ｍ２／ｇ以上である炭素微粉末を用いることによ
り、炭素微粉末上に吸着した貴金属粒子を凝集させるこ
となく、より高分散な状態で担持することができ、触媒
活性を向上させて高い放電特性を有する固体高分子型燃
料電池を得ることができる。さらにアセチレンを原料と
する不純物の含有量が少ない炭素微粉末を用いることに
より、不純物による特性劣化を防ぎ、燃料電池の寿命特
性を向上させることができる。
【０００７】
【実施例】以下、実施例により本発明をさらに詳しく説
明する。
【０００８】表面積の異なる炭素微粉末担体として、導
電性カーボンブラック、アセチレンブラックの中から表
１に示すＡ、Ｂ、Ｃ、Ｄ、Ｅの５種類の炭素微粉末を選
定した。炭素微粉末担体の比表面積および細孔容積分布
の測定にはＮ2吸着装置（カルロエルバ社製ソフトマチ
ック１８００）を用いＢ．Ｅ．Ｔ法およびＢ．Ｊ．Ｔ法
により算出した。
【０００９】
【表１】
【００１０】（実施例１）触媒の調製方法として、まず
塩化白金酸（Ｈ2ＰｔＣｌ6）１ｇの水溶液３００ｍｌに
還元剤として亜硫酸水素ナトリウム（ＮａＨＳＯ3）１
０ｇ、コロイド凝集防止剤として過酸化水素（Ｈ2Ｏ2）
１５０ｍｌを添加して白金酸化物のコロイドの水溶液１
００ｍｌを加えて生成させた白金コロイドと、比表面積
８３５ｍ2／ｇのアセチレンブラックＡの分散液とを混
合して白金触媒を担持させた炭素微粉末触媒Ａ’を作製
した。つぎにこのＡ’とフッ素樹脂により撥水化処理し
た炭素微粉末とを混合し、導電性カーボンペーパーに加
圧成型して電極を作製した。白金触媒量は両極とも電極
面積当たりの白金重量で０．０１〜０．５mg／cm2とし
た。つぎに、この電極表面に電極面積当たり０．１〜
３．０mg／cm2のイオン交換樹脂を塗布した。この電極
とイオン交換膜とを１２０〜１５０℃、２０〜６０kg／
cm2でホットプレスして負極とイオン交換膜と正極との
接合を行った。この接合体を用いて、図１に示した固体
高分子型燃料電池の単電池Ａｃを作製した。図１中、１
０はイオン交換膜を示し、本実施例では米国デュポン社
製のＮａｆｉｏｎ１１７を用いた。１１および１２はそ
れぞれ負極および正極を示す。
【００１１】（実施例２）実施例１において、触媒担体
である炭素微粉末に比表面積１５００ｍ2／ｇのカーボ
ンブラックＢを用いた以外は実施例１と全く同じとし
た。本実施例の触媒担持炭素微粉末Ｂ’とし、この触媒
Ｂ’を用いて電極を作製し、この電極を用いて作製した
固体高分子型燃料電池の単電池をＢｃとする。
【００１２】（比較例１）実施例１において、触媒担体
である炭素微粉末に比表面積１４７５ｍ2／ｇのカーボ
ンブラックＣを用いた以外は実施例１と全く同じとし
た。本実施例の触媒担持炭素微粉末をＣ’とし、この触
媒Ｃ’を用いて電極を作製し、この電極を用いて作製し
た固体高分子型燃料電池の単電池をＣｃとする。
【００１３】（比較例２）実施例１において、触媒担体
である炭素微粉末に比表面積５８ｍ2／ｇのアセチレン
ブラックを用いた以外は実施例１と全く同じとした、本
実施例の触媒担持炭素微粉末をＤ’とし、この触媒Ｄ’
を用いて電極を作製し、この電極を用いて作製した固体
高分子型燃料電池の単電池をＤｃとする。
【００１４】（比較例３）実施例１において、触媒担体
である炭素微粉末に比表面積２５４ｍ2／ｇのカーボン
ブラックＥを用いた以外は実施例１と全く同じとした。
本実施例の触媒担持炭素微粉末をＥ’とし、この触媒
Ｅ’を用いて電極を作製し、この電極を用いて作製した
固体高分子型燃料電池の単電池をＥｃとする。
【００１５】以上本発明の実施例および比較例の単電池
の負極側に９０℃の温度で加湿した水素ガスを、正極側
に８０℃の温度で加湿した酸素ガスをそれぞれ供給して
放電試験を行った。
【００１６】図２に本発明の実施例および比較例の単電
池の放電特性を示した。比較例の単電池Ｃｃ、Ｄｃ、Ｅ
ｃは電流密度２００ｍＡ／ｃｍ2においてそれぞれ０．
５８Ｖ，０．５４Ｖ，０．５６Ｖであるのに対し、本実
施例の単電池Ａｃ，Ｂｃは電流密度２００ｍＡ／ｃｍ2
においてそれぞれ０．６９Ｖ，０．６６Ｖであった。す
なわち、電流密度２００ｍＡ／ｃｍ2においてＡｃ，Ｂ
ｃの電圧はＣｃ，Ｄｃ，Ｅｃと比較して約０．１Ｖ程高
性能であることがわかる。
【００１７】図３に本発明の触媒の炭素微粉末担体の比
表面積と白金粒子径との関係を示した。炭素微粉末担体
の比表面積が増加するほど白金粒子径が小さくなる一般
的な傾向を示した。ここで白金粒子径の測定にはＣｏ吸
着装置（大倉理研（株）製モデルＲ６０１５）を用い
た。白金粒子径が小さいほど、即ち触媒表面積が大きい
ほど電極反応の活性が向上し、単電池の放電特性が向上
することが推察されたが、図２に示したように、各単電
池の電流密度２００ｍＡ／ｃｍ2における放電特性は比
表面積の大きい炭素微粉末を用いた単電池が必ずしも高
い特性を示さなかった。
【００１８】
【表２】
【００１９】表２に炭素微粉末Ａ、ＢおよびＣの直径２
５〜７０Åの細孔容積の全細孔容積に対する割合を示し
た。また、図４に炭素微粉末Ａ〜Ｅの細孔容積の分布を
示した。高い特性を示した順に、その電池に使用した炭
素微粉末の直径２５〜７０Åの占める細孔容積の割合が
大きくなっている。また、炭素微粉末Ａと比較してＢ及
びＣは約２倍の比表面積を有するが、２５〜７０Åの細
孔容積の全細孔容積に対する割合はＡよりも小さく、そ
の比表面積の多くが２５Å以下の細孔で占められてい
る。特に炭素微粉末Ｃは１４７５ｍ２／ｇの比表面積を
有するが、直径２５〜７０Åの細孔の占める容積の全細
孔容積に対する割合が１１．６％とかなり低いため、触
媒反応への担体の効果が小さくなっている。よって、触
媒反応には直径２５〜７０Åの細孔に担持された触媒が
寄与しており、本発明の直径２５〜７０Åの細孔によっ
て表面積の大部分を占める炭素微粉末を用いた触媒が有
効であると考えられる。本実施例では特に、直径２５〜
７０Åの細孔部の容積が全細孔容積の３０．１％以上を
占める炭素微粉末を用いた触媒が効果的であったが、２
５％以上であれば同様の効果が得られた。
【００２０】図５に本発明の実施例および比較例の単電
池の定電流放電（２００ｍＡ／ｃｍ 2）における電池電
圧を示した。本発明の実施例Ａｃおよび比較例Ｄｃは１
０００時間経過後も電圧は低下しなかったが、実施例Ｂ
ｃおよび比較例Ｃｃ、Ｅｃは徐々に電圧が低下した。
【００２１】
【表３】
【００２２】表３に本実施例および比較例の炭素微粉末
Ａ、Ｅ、および触媒Ａ’、Ｅ’の蛍光Ｘ線分析の結果を
示す。本発明の実施例のアセチレンブラック系の炭素微
粉末Ａにはごく微量の硫黄が含まれているが塩素は全く
含まれていなかった。触媒Ａ’は硫黄、塩素は全く含ま
れなかった。一方比較例のカーボンブラック系の炭素微
粉末Ｅには硫黄、塩素がともに大量に含まれており、触
媒Ｅ’には硫黄が残留している。また、本発明及び比較
例の触媒担持炭素微粉末を８０℃の硫酸（１．５Ｍ）中
に浸漬し、耐久性を検討したところ、カーボンブラック
系の炭素微粉末はアセチレンブラック系の炭素微粉末に
比べて腐食劣化する傾向が見られた。
【００２３】以上のことよりカーボンブラック系の炭素
微粉末を担体とした触媒担持炭素微粉末は触媒被毒物質
である硫黄を含有するため貴金属触媒の被毒が起こり、
電池電圧の低下が起こると考えられる。一方、アセチレ
ンブラック系の炭素微粉末を担体とした触媒担持炭素微
粉末は触媒被毒物質である塩素や硫黄を含有しないため
に貴金属触媒の被毒が起こらず、電池電圧の低下は起こ
らない。従って電池の寿命特性を考慮すると、固体高分
子型燃料電池にはより不純物の少ない炭素微粉末、例え
ばアセチレンブラック系の炭素微粉末を触媒担体として
用いた貴金属触媒が有効であると考えられる。
【００２４】また、本発明では、貴金属触媒として塩化
白金酸を用いたが、他の貴金属塩を用いても、酸化還元
されやすい材料については同様の効果が期待できる。さ
らに本実施例では、固体高分子型燃料電池の一例として
水素−酸素燃料電池を取り上げたが、メタノール、天然
ガスやナフサなどを燃料とする改質水素を用いた燃料電
池、また、酸化剤として空気を用いた燃料電池に適用す
ることも可能である。
【００２５】
【発明の効果】以上のように、本発明によれば、炭素微
粉末上の反応に有効なサイトに、高活性な貴金属粒子を
微粒子状態のまま担持させることができ、さらに、２５
〜７０Åの細孔が占める容積が全細孔容積の３０．１％
以上を占め、かつ比表面積が８００ｍ２／ｇ以上である
炭素微粉末を用いることにより、炭素微粉末上に吸着し
た貴金属粒子を凝集させることなくより高分散な状態で
担持することができる。さらにより不純物の少ないアセ
チレン系の炭素微粉末を触媒担体に用いることにより、
不純物による特性劣化を防ぐことができる。よって、優
れた放電特性を持ち、寿命特性の優れた固体高分子型燃
料電池を提供できる。DETAILED DESCRIPTION OF THE INVENTION
[0001]
The present invention relates to pure hydrogen as a fuel,
Uses reducing agents such as methanol and reformed hydrogen from fossil fuels.
Polymer fuel cell using air or oxygen as oxidant
It is about.
[0002]
2. Description of the Related Art A polymer electrolyte fuel cell has an operating temperature of 60.
Because the temperature is as low as ~ 150 ° C, the electrode has a highly active noble metal catalyst,
In particular, platinum catalysts are used. To improve its characteristics,
The form of the noble metal catalyst used for the electrode and its dispersion
To give high activity, especially on fine carbon powder.
Important technology to support metal particles in a highly dispersed state
It is said. Therefore, there are many precious metal catalyst loading methods.
Research has been done. For example, a high dispersion of noble metal particles
Carbon as a carrier to be supported on carbon fine powder in a state
Destroys the three-dimensional structure of the fine powder and adsorbs noble metal particles
There has been proposed a method of increasing the noise (JP-A-63-31163).
No. 9050). Also, same as polymer electrolyte fuel cell
Methanol fuel cell that operates at low temperatures and uses a noble metal catalyst
For methanol oxidation catalysts for ponds,
Preparing colloidal particles of precious metal and marketing the colloidal particles
50-300m of salesTwo/ G fine powder with specific surface area
Method of depositing on top (JP-A-63-97232)
And the pore distribution and specific surface area of carbon fine powder
(Japanese Unexamined Patent Publication No. Hei 3-101057)
Information).
[0003]
SUMMARY OF THE INVENTION Such a conventional precious money
In the group catalysts, carriers as catalysts for polymer electrolyte fuel cells
Investigations on the carbon fine powder to be
The dispersion state of noble metal particles varies depending on the type of carbon fine powder
Has the disadvantage that sufficient discharge characteristics have not been obtained.
I was In addition, a catalyst poisoning substance is added to carbon fine powder as a carrier.
Long enough to contain certain impurities such as chlorine and sulfur
There was a drawback that life characteristics were not obtained.
The present invention solves the above-mentioned conventional problems.
The pore distribution and ratio of the fine carbon powder used as a support for the noble metal catalyst
Find optimal conditions such as surface area and contain impurities
By using a small amount of carbon fine powder, high discharge
Solid polymer fuel with excellent properties and excellent life characteristics
It is intended to provide a battery.
[0005]
[MEANS FOR SOLVING THE PROBLEMS]
The polymer electrolyte fuel cell of the present invention has a diameter of25-70Åof
The volume occupied by the pores is 30.1% or more of the total pore volume.
Carbon powder with a specific surface area of 800 m2 / g or more
Highly dispersed noble metal catalyst and water-repellent charcoal
Form a mixture layer with fine powder on conductive carbon paper
And an ion exchange resin was applied to the surface of the mixture layer.
It is characterized by using electrodes.
[0006]
According to this configuration, the diameter of the carbon fine powder is25-7
0ÅOf catalytic noble metal particles with pores of 10 to 30 mm in diameter
Highly active at the site effective for reaction on carbon fine powder
Noble metal particles can be supported as fine particles
You. Furthermore, it has a pore diameter in the above range and a specific surface area of 8
By using a carbon fine powder of at least 00 m2 / g
And aggregate the noble metal particles adsorbed on the carbon fine powder.
The catalyst can be supported in a highly dispersed state
Solid polymer type fuel with high discharge characteristics with improved activity
Fuel cell can be obtained. Acetylene as raw material
Use of carbon fine powder with low content of impurities
To prevent deterioration of characteristics due to impurities,
Performance can be improved.
[0007]
The present invention will be described in more detail with reference to the following examples.
I will tell.
[0008] As a carbon fine powder carrier having a different surface area,
Table from among conductive carbon black and acetylene black
5 kinds of fine carbon powders of A, B, C, D and E shown in FIG.
Specified. Specific surface area and pore volume distribution of carbon fine powder carrier
N to measureTwoAdsorption device (Carloelba soft gusset)
1800). E. FIG. T method and B. J. T method
Was calculated by
[0009]
[Table 1]
(Example 1) As a method for preparing a catalyst, first,
Chloroplatinic acid (HTwoPtCl6) 300ml of 1g aqueous solution
Sodium bisulfite (NaHSOThree) 1
0 g, hydrogen peroxide (HTwoOTwo)
Add 150 ml of aqueous solution of colloidal platinum oxide 1
Platinum colloid formed by adding 00 ml and specific surface area
835mTwo/ G of acetylene black A dispersion.
To produce a carbon fine powder catalyst A 'carrying a platinum catalyst
did. Next, water-repellent treatment is performed with A 'and a fluororesin.
Mixed with fine carbon powder and added to the conductive carbon paper.
An electrode was produced by pressing. The amount of platinum catalyst is electrode for both electrodes
0.01-0.5mg / cm in platinum weight per areaTwoage
Was. Next, the surface of the electrode was 0.1 to
3.0mg / cmTwoWas applied. This electrode
And an ion exchange membrane at 120 to 150 ° C and 20 to 60 kg /
cmTwoHot pressing with the negative electrode, the ion exchange membrane and the positive electrode.
Joining was performed. Using this joint, the solid shown in FIG.
A single cell Ac of a polymer fuel cell was manufactured. In FIG. 1, 1
0 indicates an ion exchange membrane, and in this embodiment, DuPont, USA
Nafion 117 was used. 11 and 12
A negative electrode and a positive electrode are shown, respectively.
(Example 2) In Example 1, the catalyst carrier
Specific surface area of 1500mTwo/ G carb
Except that black B was used.
Was. The catalyst-carrying carbon fine powder B 'of this example was
An electrode was fabricated using B 'and fabricated using this electrode.
A cell of the polymer electrolyte fuel cell is denoted by Bc.
Comparative Example 1 In Example 1, the catalyst carrier was used.
Specific surface area of 1475mTwo/ G carb
Except for using black C, the same as in Example 1
Was. The catalyst-carrying carbon fine powder of this example was designated as C '
An electrode is manufactured using the medium C ′, and an electrode is manufactured using the electrode.
The unit cell of the polymer electrolyte fuel cell is denoted by Cc.
Comparative Example 2 In Example 1, the catalyst carrier was used.
Specific surface area of 58mTwo/ G of acetylene
Except that black was used, the book
The catalyst-carrying carbon fine powder of the example was D ', and this catalyst D'
An electrode is made using a solid, and a solid made using this electrode
The unit cell of the polymer fuel cell is Dc.
Comparative Example 3 In Example 1, the catalyst carrier was used.
Specific surface area of 254mTwo/ G of carbon
Except that Black E was used, it was exactly the same as Example 1.
The catalyst-carrying carbon fine powder of this example was designated as E '
An electrode was fabricated using E 'and fabricated using this electrode.
The unit cell of the polymer electrolyte fuel cell is Ec.
The cells of the examples and comparative examples of the present invention
Hydrogen gas humidified at a temperature of 90 ° C.
Oxygen gas humidified at a temperature of 80 ° C.
A discharge test was performed.
FIG. 2 shows a single cell according to an embodiment of the present invention and a comparative example.
The discharge characteristics of the pond were shown. Cell Cc, Dc, E of Comparative Example
c is the current density of 200 mA / cmTwoAt 0.
58V, 0.54V, 0.56V
The cells Ac and Bc of the embodiment have a current density of 200 mA / cm.Two
Were 0.69 V and 0.66 V, respectively. You
That is, the current density is 200 mA / cm.TwoIn Ac, B
The voltage of c is about 0.1 V higher than Cc, Dc and Ec.
It turns out that it is performance.
FIG. 3 shows the ratio of the carbon fine powder carrier of the catalyst of the present invention.
The relationship between the surface area and the platinum particle size was shown. Carbon fine powder carrier
As the specific surface area increases, the particle diameter of platinum decreases.
Showed a tendency. Here, when measuring the platinum particle size, Co absorption was used.
Using a wearing device (Model R6015 manufactured by Okura Riken Co., Ltd.)
Was. The smaller the platinum particle size, the larger the catalyst surface area
The higher the electrode reaction activity, the better the cell's discharge characteristics
However, as shown in FIG.
Current density of the pond 200mA / cmTwoThe discharge characteristics at
Single cells using carbon fine powder with large surface area
Did not show good properties.
[0018]
[Table 2]
Table 2 shows the diameters of the fine carbon powders A, B and C.2
5-70ÅIndicates the ratio of the pore volume to the total pore volume
Was. FIG. 4 shows the distribution of the pore volumes of the fine carbon powders A to E.
Indicated. The order in which the battery exhibited the highest characteristics
Fine powder diameter25-70ÅOf the pore volume occupied by
It is getting bigger. In addition, compared to carbon fine powder A, B and
And C have about twice the specific surface area,25-70ÅDetail
The ratio of the pore volume to the total pore volume is smaller than A,
Of the specific surface area is occupied by pores of 25 mm or less.
You. In particular, carbon fine powder C has a specific surface area of 1475 m2 / g.
Has but a diameter25-70ÅOf the volume occupied by the pores
Since the ratio to the pore volume is as low as 11.6%,
The effect of the carrier on the medium reaction is reduced. Therefore, touch
A catalyst supported in pores having a diameter of 25 to 70 ° is used for the medium reaction.
The diameter of the present invention25-70ÅThe pores of
Catalyst using carbon fine powder occupying most of the surface area
It is considered to be effective. In this embodiment, in particular, the diameter25-
70ÅThe pore volume of the30.1%Above
The catalyst using carbon fine powder occupied was effective, but 2
The same effect was obtained when the content was 5% or more.
FIG. 5 shows a single cell of the embodiment of the present invention and a comparative example.
Constant current discharge of the pond (200 mA / cm Two)
Pressure indicated. In Example Ac and Comparative Example Dc of the present invention, 1
Although the voltage did not decrease even after lapse of 000 hours, Example B
The voltage of c and the comparative examples Cc and Ec gradually decreased.
[0021]
[Table 3]
Table 3 shows carbon fine powders of this example and a comparative example.
A and E, and the results of X-ray fluorescence analysis of catalysts A 'and E'
Show. Acetylene black-based carbon fines of Examples of the present invention
Powder A contains a very small amount of sulfur but no chlorine
Was not included. Catalyst A 'contains no sulfur or chlorine
Was not. On the other hand, the carbon black of the comparative example
Powder E contains a large amount of both sulfur and chlorine.
Sulfur remains in the medium E '. In addition, the present invention and comparison
Example catalyst fine carbon powder supported in sulfuric acid (1.5M) at 80 ° C
When immersed in carbon black and examined for durability, carbon black
-Based carbon fine powder is replaced with acetylene black-based carbon fine powder.
There was a tendency for corrosion deterioration.
From the above, carbon black based carbon
Catalyst-supported carbon fine powder using fine powder as a carrier is a catalyst poisoning substance.
Poisoning of the noble metal catalyst occurs because it contains sulfur,
It is considered that the battery voltage drops. On the other hand, acetylene
Catalyst supported carbon fines using carbon black powder
Because the powder does not contain chlorine or sulfur, which is a catalyst poisoning substance
No noble metal catalyst poisoning occurs, and the battery voltage drops.
No. Therefore, considering the battery life characteristics,
Carbon fine powder with less impurities, for example,
Acetylene black carbon powder as catalyst carrier
The noble metal catalyst used is considered to be effective.
In the present invention, the noble metal catalyst
Although platinic acid was used, even if other noble metal salts were used, redox
Similar effects can be expected for materials that are apt to be damaged. Sa
Further, in this embodiment, as an example of the polymer electrolyte fuel cell,
The hydrogen-oxygen fuel cell was taken up, but methanol, natural
Fuel cells using reformed hydrogen fueled by gas, naphtha, etc.
Pond and fuel cells using air as oxidant.
It is also possible.
[0025]
As described above, according to the present invention, carbon fines
Highly active noble metal particles on sites effective for reaction on powder
It can be supported in the state of fine particles.
The volume occupied by ~ 70 ° pores is the total pore volume30.1%
Occupies more than 1, and the specific surface area is 800 m2 / g or more.
By using carbon fine powder, it is adsorbed on carbon fine powder.
In a highly dispersed state without agglomerated precious metal particles
Can be carried. Ace with even less impurities
By using a fine carbon powder of the Tylene type as the catalyst carrier,
Characteristic degradation due to impurities can be prevented. Therefore,
Solid polymer fuel with excellent discharge characteristics and excellent life characteristics
Battery can be provided.
【図面の簡単な説明】
【図１】固体高分子型燃料電池の単電池の断面図
【図２】本発明の実施例および比較例の固体高分子型燃
料電池の電流−電圧特性を示した図
【図３】本発明の実施例および比較例の炭素微粉末の比
表面積と白金粒子径の関係を示した図
【図４】本発明の実施例および比較例の炭素微粉末の細
孔容積の分布を示した図
【図５】本発明の実施例および比較例の単電池の定電流
放電特性を示した図
【符号の説明】
１０ イオン交換膜
１１ 負極
１２ 正極BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a unit cell of a polymer electrolyte fuel cell. FIG. 2 shows current-voltage characteristics of polymer electrolyte fuel cells of Examples and Comparative Examples of the present invention. FIG. 3 is a diagram showing the relationship between the specific surface area and the platinum particle diameter of the fine carbon powder of the examples and comparative examples of the present invention. FIG. 4 is the pore volume of the fine carbon powder of the examples and comparative examples of the present invention. FIG. 5 is a diagram showing the constant current discharge characteristics of the unit cells of Examples and Comparative Examples of the present invention. [Description of References] 10 Ion exchange membrane 11 Negative electrode 12 Positive electrode
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平３−208260（ＪＰ，Ａ) 特開 平３−101057（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) H01M 4/86 - 4/96,8/10 B01J 21/18,23/40 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-208260 (JP, A) JP-A-3-101057 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) H01M 4/86-4 / 96,8 / 10 B01J 21 / 18,23 / 40
Claims (1)
細孔容積の３０．１％以上であり、かつ比表面積が８０
０ｍ２／ｇ以上の炭素微粉末に高分散された貴金属から
なる触媒と、撥水化処理した炭素微粉末との混合物層を
導電性カーボンペーパー上に形成し、前記混合物層の表
面にイオン交換樹脂を塗布した電極を用いた固体高分子
型燃料電池。(57) Claims 1. The volume occupied by pores having a diameter of 25 to 70 ° is 30.1% or more of the total pore volume, and the specific surface area is 80%.
A mixture layer of a catalyst made of a noble metal highly dispersed in a carbon fine powder of 0 m2 / g or more and a carbon fine powder subjected to a water-repellent treatment is formed on conductive carbon paper, and an ion exchange resin is formed on the surface of the mixture layer. Polymer fuel cell using an electrode coated with a polymer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34592892A JP3407320B2 (en) | 1992-12-25 | 1992-12-25 | Polymer electrolyte fuel cell |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34592892A JP3407320B2 (en) | 1992-12-25 | 1992-12-25 | Polymer electrolyte fuel cell |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06196171A JPH06196171A (en) | 1994-07-15 |
| JP3407320B2 true JP3407320B2 (en) | 2003-05-19 |
Family
ID=18379950
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP34592892A Expired - Fee Related JP3407320B2 (en) | 1992-12-25 | 1992-12-25 | Polymer electrolyte fuel cell |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3407320B2 (en) |
Families Citing this family (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09257687A (en) * | 1996-01-16 | 1997-10-03 | Matsushita Electric Ind Co Ltd | Measuring method for reaction specific surface area and utilization factor of noble metal catalyst at solid polymer-type fuel cell and catalyst layer for electrode for solid polymer-type fuel cell |
| US6339038B1 (en) * | 1998-06-16 | 2002-01-15 | Tanaka Kikinzoku Kogyo K. K. | Catalyst for a fuel cell containing polymer solid electrolyte and method for producing catalyst thereof |
| WO2000011688A1 (en) * | 1998-08-25 | 2000-03-02 | Kanebo, Limited | Electrode material and method for producing the same |
| JP2002134119A (en) * | 2000-10-19 | 2002-05-10 | Japan Storage Battery Co Ltd | Fuel cell and electrode for fuel cell |
| EP1357618A1 (en) | 2001-03-08 | 2003-10-29 | Matsushita Electric Industrial Co., Ltd. | Polymer electrolyte type fuel cell |
| JP2003128409A (en) * | 2001-10-22 | 2003-05-08 | Ube Ind Ltd | Porous carbon film, catalyst carrier, electrode for fuel battery, material for connecting electrode and fuel battery |
| CA2618312A1 (en) * | 2001-12-27 | 2003-07-10 | Hitachi Chemical Company, Ltd. | Separator for fuel cell |
| US7041403B2 (en) * | 2003-02-25 | 2006-05-09 | Utc Fuel Cells | Fixed IDC operation of fuel cell power plant |
| JP4815823B2 (en) * | 2004-03-31 | 2011-11-16 | 三菱化学株式会社 | Fuel cell catalyst and method for producing the same, fuel cell electrode and fuel cell using the same |
| US20060134506A1 (en) * | 2004-12-17 | 2006-06-22 | Kim Min S | Electrode catalyst for fuel cell |
| JP4696299B2 (en) * | 2005-07-20 | 2011-06-08 | 独立行政法人産業技術総合研究所 | Composites of porous carbon and metal nanoparticles with sharp pore size distribution |
| CN100344021C (en) * | 2005-08-23 | 2007-10-17 | 天津大学 | Production of platinum/carbon catalyst from inorganic glue |
| JP2008041498A (en) * | 2006-08-08 | 2008-02-21 | Sharp Corp | Method of manufacturing catalyst support body for polymer electrolyte fuel cell, and polymer electrolyte fuel cell |
| CN105142784A (en) | 2013-04-25 | 2015-12-09 | 日产自动车株式会社 | Catalyst, electrode catalyst layer using said catalyst, membrane electrode assembly, and fuel cell |
| EP2990104B1 (en) | 2013-04-25 | 2019-10-16 | Nissan Motor Co., Ltd | Catalyst, method for producing same, and electrode catalyst layer using said catalyst |
| CA2910242C (en) | 2013-04-25 | 2019-01-22 | Nissan Motor Co., Ltd. | Catalyst, and electrode catalyst layer, membrane electrode assembly and fuel cell using the catalyst |
| WO2016067878A1 (en) | 2014-10-29 | 2016-05-06 | 日産自動車株式会社 | Electrode catalyst layer for fuel cell, manufacturing method for same, and membrane electrode assembly and fuel cell using same |
| CN110383548B (en) * | 2017-02-23 | 2023-01-06 | 松下知识产权经营株式会社 | Membrane electrode assembly and fuel cell |
-
1992
- 1992-12-25 JP JP34592892A patent/JP3407320B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06196171A (en) | 1994-07-15 |
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