Bibliographic Citation
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Title | Perfluoro-ethylene-1,2-bis-phosphoric acid fuel cell electrolyte |
Creator/Author | Kanamura, K. ; Tanaka, A. ; Gervasio, D. ; Kennedy, V. ; Adzic, R. ; Yeager, E.B. [Case Western Reserve Univ., Cleveland, OH (United States)] ; Burton, D. ; Guneratne, R. [Univ. of Iowa, Iowa City, IA (United States). Dept. of Chemistry] |
Publication Date | 1996 Sep 01 |
OSTI Identifier | OSTI ID: 404632 |
Other Number(s) | JESOAN; ISSN 0013-4651 |
Resource Type | Journal Article |
Resource Relation | Journal of the Electrochemical Society ; VOL. 143 ; ISSUE: 9 ; PBD: Sep 1996 |
Subject | 30 DIRECT ENERGY CONVERSION ; ACID ELECTROLYTE FUEL CELLS; ELECTROLYTES; MATERIALS TESTING; PHOSPHONIC ACIDS; HYDROGEN FUEL CELLS; REDOX REACTIONS; PLATINUM; CATALYTIC EFFECTS |
Description/Abstract | Concentrated aqueous perfluoroethylene-1,2-bis-phosphonic acid has been investigated as an alternative to phosphoric acid as the electrolyte in the H{sub 2}/O{sub 2} acid fuel cell. Phosphoric and bis-phosphonic acid solutions were equilibrated with pure O{sub 2} (P= 1 atm) and were used in (1) chronoamperometry experiments performed with a Pt microelectrode to estimate the O{sub 2} diffusion coefficient, D, and solubility, C, and (2) O{sub 2} electroreduction polarization studies done with a gas-fed Teflon-bonded carbon electrode with a high surface area Pt catalyst in a microfuel cell. At 22 C in 85% bis-phosphonic acid, C was found to be 3.4{+-} 0.3{times} 10{sup{minus}4} mol/liter and D was 5.0{+-} 10{sup{minus}7} cm{sup 2}/s as compared with C= 2.8{+-} 0.3{times} 10{sup{minus}4} mol/liter and D= 1.2{+-} 0.1{times} 10{sup{minus}6} cm{sup 2}/s in 85% phosphoric acid at T= 22 C. The over-potential for O{sub 2} reduction on the microfuel cell cathode was smaller in 85% bis-phosphonic acid than in 85% phosphoric acid for current densities up to 200 mA/mcm{sup 2} at 100 C. This indicates that the oxygen electroreduction kinetics on Pt increased when phosphoric acid was replaced with the perfluorinated bis-phosphonic acid. At higher current densities where mass transport may influence cathode performance, the performance with bis-phosphonic acid was not as good as with phosphoric acid at 100 C, which is consistent with the higher viscosity and lower D found for bis-phosphonic acid relative to phosphoric acid at 22 C. As the temperature was raised from 100 to 200 C, the cathode performance improved with the bis-phosphonic acid electrolyte. The enhanced O{sub 2} reduction kinetics with the bis-phosphonic acid persistend in the fuel cell environment at temperatures up to 200 C for 500 h which demonstrated a major improvement in stability for a high performance perfluorinated fuel cell electrolyte used at higher temperatures such as 200 C. |
Country of Publication | United States |
Language | English |
Format | pp. 2765-2770 ; PL: |
System Entry Date | 2001 May 05 |
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