Accession Number : AD0863067

Title :   Molecular Engineering of Pt-Based Electrocatalysts for Hydrocarbon Fuel Cell Electrodes.

Descriptive Note : Semiannual interim rept. no. 5, 1 Nov 68-30 Apr 69,

Corporate Author : TYCO LABS INC WALTHAM MA

Personal Author(s) : Giner, J. ; Parry, J. M. ; Smith, S. M.

Report Date : JUN 1969

Pagination or Media Count : 51

Abstract : The report describes continued studies of the factors controlling the activity of Pt black catalysts for the anodic oxidation of hydrocarbons. Particular attention has been given to the separation of structural (mass transport) influences on activity and the differences in the intrinsic activity of the catalyst (i.e. the activity per real square centimeter of the surface). Significant progress was made in developing a technique for the measurement of intrinsic activity. This technique is based on the galvanostatic oxidation of a strongly adsorbed intermediate of the propane oxidation reaction (O-type). It was shown that at 90C, the rate of formation of CH -beta is slow enough to permit a study of O-type oxidation as a unique surface species. The shape of the galvanostatic trace is, also, very similar to that for reduced CO2. The attainment of uniform surface coverage, however, particularly on those areas of the surface deep in the pore structure is still questionable because of the limited rate of diffusion of propane. An assessment of this sensitivity was carried out by comparing the results of measurements made with C3H8 at 90C with measurements made with 'reduced CO2.' Also, thirteen platinum-on-carbon catalysts were prepared. The objectives were to prepare catalysts in which the crystallite size could be varied without simultaneously changing the agglomerate structure. (Author)

Descriptors :   *CATALYSTS), *ANODES(ELECTROLYTIC CELL)), (*FUEL CELLS, (*PLATINUM, CARBON, GRAPHITE, TRANSPORT PROPERTIES, SURFACE PROPERTIES, OXIDATION, PROPANE, CARBON DIOXIDE, HYDROCARBONS.

Subject Categories : Physical Chemistry
      Electric Power Production and Distribution

Distribution Statement : APPROVED FOR PUBLIC RELEASE