PRETREATMENT OF ACETYLENE BLACK - INFLUENCE ON ELECTROCHEMICAL-BEHAVIOR

Electrochemical methods and two other non-electrochemical methods, viz., transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FT-IR) have been used to study changes in the characteristics of acetylene black in the cathode of fuel cells when acetylene black is treated under three different conditions: (i) no further treatment; (ii) in air at 450-degrees-C, and (iii) in a CO2 stream at 900-degrees-C. The latter two methods increase the surface area of acetylene black at a given condition from 70 to 116 and 104 m2 g-1, respectively. By contrast, there is a large difference in the electrochemical behaviour. This phenomenon is considered to be due to the partial graphitization of acetylene black at high temperature.