The ORR may initiate through either molecular oxygen dissociation or reduction elementary reactions. Though dissociation is a non-electrochemical reaction, variations in electrode potential alter the interactions of both the adsorbed state and the dissociation transition state with the catalyst surface, thereby making the barrier to dissociation dependent on the electrode potential. Results from density functional theory (DFT) calculations illustrate the coupling between the effects of potential variation and solvation on the dissociation barrier. Though electron transfer from the surface to O-O antibonding orbitals is enhanced at more negative (reducing) potentials, the dissociation barrier decreases at more positive potentials. This counterintuitive trend is due to enhanced stabilization of the dissociation transition state at more positive potentials. Co-adsorption of alkali species at the surface lowers the oxygen dissociation barrier at all potentials. The activation barrier to the initial reduction step, reducing adsorbed oxygen to OOH, is also dependent on the electrode potential, decreasing at more negative potentials. The relative rates of these two reactions is therefore potential dependent. Furthermore, the reduction energetics are dependent on the electrolyte structure at the interface. Dependence of reduction energetics on the interfacial water density and structure determined using DFT methods will be presented. Initial efforts in developing a multi-scale, integrated molecular dynamics and DFT approach to determining the interfacial structure dependence of ORR rates will be discussed.