Accession Number : AD0455564


Title :   FUEL CELL CATALYSTS.


Descriptive Note : Quarterly rept. no. 3, 1 Jun-31 Aug 64,


Corporate Author : ENGELHARD INDUSTRIES INC EAST NEWARK NJ


Personal Author(s) : Adlhart, O J


Report Date : 31 Aug 1964


Pagination or Media Count : 33


Abstract : An evaluation of carrier materials for electro catalysts in concentrated HPO4 and H2SO4 electrolytes was carried out with carbon, carbides, silicides, borides and oxides. Promising chemical stability was exhibited by tantalum silicide, tantalum oxide, tungsten oxide, tungsten carbide and boron carbide. Carbon was chemically stable and was not corroded after activation with Pt at temperatures up to 200 C and anodic potentials up to 0.5 volts vs. hydrogen. Carbon was rapidly oxidized, at potentials of cathode operation. The performance, thermal stability and life of precious metal catalysts was materially affected by the pore structure, surface area and particle size of the carrier materials. Substrates of low porosity and small particle size yielded catalysts of superior activity. Thermal stability was improved by the use of microporous carriers of high surface areas. Certain Pt-Ru alloys may be successfully supported on carriers of low porosity due to an unusual, as yet unexplained, stability. (Author)


Descriptors :   CATALYSTS , FUEL CELLS , CARBON , PLATINUM ALLOYS , CARBON BLACK , CARBIDES , SILICIDES , BORIDES , OXIDES , TUNGSTEN COMPOUNDS , BORON COMPOUNDS , POROSITY , PARTICLE SIZE , STABILITY , SURFACES , ELECTRODES , OXIDATION , ELECTROCHEMISTRY


Distribution Statement : APPROVED FOR PUBLIC RELEASE