New electrolytes for direct methane fuel cells. Final report, January 10,1977-January 9, 1979. [Methanesulfonic acids]

Technical Report · Tue May 01 00:00:00 EDT 1979

DOI:https://doi.org/10.2172/5712244· OSTI ID:5712244

Brummer, S B; Foos, J; McHardy, J; McVeigh, J; Toland, D; Turner, M

The program is aimed at developing a fuel cell electrolyte for the direct oxidation of CH/sub 4/ and/or impure H/sub 2/ fuels. Of interest are di- and tribasic methanesulfonic acids CX/sub 2/(SO/sub 3/H)/sub 2/ and CX(SO/sub 3/H)/sub 3/ where X is H, F, or C1. Synthetic routes to CH/sub 2/(SO/sub 3/H)/sub 2/, CH(SO/sub 3/H)/sub 3/, CCl/sub 2/(SO/sub 3/H)/sub 2/, and CCl(SO/sub 3/H)/sub 3/ have been identified and optimized. The diphenyl ester of CF/sub 2/(SO/sub 3/H)/sub 2/ has been prepared for the first time and various approaches to CF(SO/sub 3/H)/sub 3/ have been investigated. In parallel with the synthetic program, apparatus was designed and fabricated for the testing of the electrolytes under fuel cell conditions. A new PTFE test cell was developed for testing small amounts of electrolyte. Electrodes with low Pt loading were developed for use in electrolyte evaluation. Optimum performance with H/sub 3/PO/sub 4/ was achieved using 1 mg Pt/cm/sup 2/ and 1 mg TFE 30/cm/sup 2/ deposited on TFE tape, supported on a Au plated Ta screen, and sintered. Preliminary half cell tests using CH/sub 2/(SO/sub 3/H)/sub 2/ and CH(SO/sub 3/H)/sub 3/ indicated that these acids are insufficiently stable for use as fuel cell electrolytes. However, tests using CCl/sub 2/(SO/sub 3/H/sub 2/) and CCl(SO/sub 3/H)/sub 3/ were encouraging, yielding H/sub 2/ oxidation rates equal to or better than those using H/sub 3/PO/sub 4/. Stability tests were conducted by heating a sample of each acid at 130/sup 0/ for 30 days under atmospheres of N/sub 2/, O/sub 2/, and H/sub 2/. At the end of the test, each sample was analyzed for decomposition. In no case did IR analysis indicate significant decomposition and, in the case of the chloroacids, only a trace amount of free Cl/sup -/ was observed. Conductivity measurements showed the aqueous acids to be of the same conductivty as aqueous H/sub 3/PO/sub 4/. The dihydrate of CH/sub 2/(SO/sub 3/H)/sub 2/ was found to be more conductive than CF/sub 3/SO/sub 3/H.H/sub 2/O but less conductive than 100% H/sub 3/PO/sub 4/.

• Research Organization: EIC Corp., Newton, MA (USA)
• DOE Contract Number: EY-76-C-03-1363
• OSTI ID: 5712244
• Report Number(s): DOE/ET/11321-T1
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
ACID ELECTROLYTE FUEL CELLS
ELECTROLYTES
HYDROCARBON FUEL CELLS
SULFONIC ACIDS
ELECTRIC CONDUCTIVITY
STABILITY
SYNTHESIS
AIR
CHEMICAL PREPARATION
CHLORINATION
ELECTRODES
HYDROGEN
METHANE
PERFORMANCE
PERFORMANCE TESTING
PHOSPHORIC ACID
TEMPERATURE DEPENDENCE
ALKANES
CHEMICAL REACTIONS
CRYOGENIC FLUIDS
DIRECT ENERGY CONVERTERS
ELECTRICAL PROPERTIES
ELECTROCHEMICAL CELLS
ELEMENTS
FLUIDS
FUEL CELLS
GASES
HALOGENATION
HYDROCARBONS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
NONMETALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PHYSICAL PROPERTIES
TESTING
300503* - Fuel Cells- Materials
Components
& Auxiliaries
300501 - Fuel Cells- Design & Development