Аннотация:Platinum/carbon fiber catalysts prepared by impregnation and electrochemical deposition were studied. It was suggested that polarization processes of two types which differ in their rates occur at their surface. A method was suggested for calculating the physiochemical constants (specific surface area of platinum, size of the metal crystals, amount of adsorbed hydrogen) of such catalysts. It was shown that Pt/CF catalysts prepared by electrochemical deposition of Pt on the CF surfaces are more highly disperse than samples of identical composition obtained by impregnation.