Particle Size Effects for Oxygen Reduction on Highly Dispersed Platinum in Acid Electrolytes

The particle size effects for oxygen reduction kinetics on highly dispersed Pt particles in acid electrolytes are discussed.It is suggested that the change in the fraction of surface atoms on the (100) crystal face of Pt particles, which are assumed to be cubo-octahedral structures, can be correlated to the mass activity (Ng Pt) and specific activity (J.LA/cm 2 Pt) of highly dispersed Pt electrocatalysts.The reduction of oxygen on supported Pt particles in acid electrolytes is classified as a "demanding" or "structure-sensitive" reaction; the specific activity increases with an increase in particle size.l.;