Oxygen reduction is central to electrochemical energy storage in a carbon-neutral energy system, e.g., in fuel cells or metal-air batteries. In this paper we discuss the kinetics of the oxygen reduction reaction in acidic media via mean-field modeling of surface adsorbents. We put a special focus on the importance of interactions between adsorbents. Our study is based on detailed ab-initio simulations of thermodynamic and kinetic parameters on the Pt(111) surface. The oxygen dissociation and the hydroperoxyl dissociation pathway are found to determine the overall reaction kinetics and to result in the double Tafel slope on Pt(111).