There have been determined (in alkaline electrolyte solution) potentiodynamic and potentiostatic characteristics of various fractions of activated carbon treated with the PTFE emulsion featuring superficial water repellency. Carbon fractions of different density resulting from various activation (burn-off) degree of granules in one batch were separated in the air stream. For particular fractions, the nitrogen adsorption and desorption isotherms were determined to calculate the parameters of carbon porous structure. The influence of differences in distribution of micro-and mesopores volume and their surface on the activity of activated carbon in the reaction of electroreduction of atmospheric oxygen have been tested.