| Project/Area Number |
11555253
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
高分子構造・物性(含繊維)
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| Research Institution | Keio University |
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Principal Investigator |
YAMAMOTO Kimihisa Keio Univ.Chemistry Assoc.Prof., 理工学部, 助教授 (80220458)
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| Co-Investigator(Kenkyū-buntansha) |
HIGUCHI Masayoshi Keio Univ.Chemistry Research Assoc., 理工学部, 助手 (80306852)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥10,300,000 (Direct Cost: ¥10,300,000)
Fiscal Year 2000: ¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 1999: ¥7,500,000 (Direct Cost: ¥7,500,000)
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| Keywords | Fuel Cell / Oxygen Electrode / Polymeric Catalyst / Conductive Polymer / Energy Conversion / 酸素極材料 / 高分子電池 |
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| Research Abstract |
Objective of this project is on Development of Oxygen Electrode for Polymer Fuel Cell Worked under Neutral and Room Temperature Conditions.
First, various π-conjugated redox polymers were synthesized by the conventional methods. Poly aniline with acidic group as a self-doping conductive polymer shows excellent redox activity over a wide pH range due to the self-dopable acidic group and acts as a polymer ligand for macromolecular metal-complexes. The catalytic behavior of the polyaniline-ionically stacked dinuclear cobalt-porphyrin complex (PCAn-Co2P,) was studied using electrochemical techniques on the modified glassy carbon electrode. We achieved the 4-electron reduction of oxygen to water in neutral conditions (pH 6.2) with more than 90% efficiency by using the self-doped polyaniline-Co-porphyrin complex. In this system poly (2,3-dicaboxy aniline) acts as an excellent electron mediator. Our study reveals that the key process of the 4-electron reduction of oxygen is the sequential electron transfer from the redox polymer to the dioxo cobalt complex after the electron transfer proceeded from cobalt to oxygen.
Polymer complexes of the polyanilines with the similar redox potential to that of cobalt porphyrine(CoII/CoIII) show a good catalytic activity for the 4-electron reduction of oxygen. Sequential electron injection into the cobalt complex takes place smoothly The catalytic efficiency drastically decreases with increase of the DG of the electron transfer process between polymer and cobalt complex.
As a strategy to achieve an efficient oxygen electrode for the fuel cell, we concluded that polyaniline derivatives should be employed as a conductive self-dopable polymer electrolyte with the similar redox potential to that of cobalt porphyrin (CoII/CoIII), in which the acidic domains in the polymer complex provides a stable catalytic activity even at elevated pH.
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