The first order surface Pourbaix diagrams constructed between free energy vs. the applied potential for van der Waal's interaction-excluded and semi-empirical methods are shown in Figure (a), and that for vdw-DF methods is given in Figure . Similarly, second order Pourbaix diagrams constructed between the applied potential vs. pH for the van der Waal's interaction-excluded and semi-empirical methods are shown in Figure (b), and that of vdw-DF methods is given in Figure . It is known that under the potential range of ~0.6-0.8 V, the Pt(111) surface would be occupied by *OH, which would be replaced via electrooxidation by *O at higher potentials. From the figure, it can be understood that in the ORR relevant potential range of >0.8 V, all the methods predict higher stability for *O occupied Pt(111) surface. Nonetheless, the relative stability differences between different states have been found to show a method dependency. When no dispersion interactions are taken into account, both PBE and RPBE functionals predict nearly a direct transition from bare Pt(111) surface to 0.33 ML*O covered surface whereas 0.33 ML *OH covered surface, which has been found to be stable for a reasonable potential range with D2 and D3 methods. This suggests that the *OH coverage-dependent interactions are treated differently when dispersion interactions are taken under consideration. The second order Pourbaix diagram also conveys important insights regarding the stability of different surface states under pH conditions (Figure ). PBE and RPBE functionals predict a longer pH range for bare Pt(111) surface without dissolution. However, when the dispersion interactions are included, the surface is featured with a lower onset pH value at which the dissolution initiates owing to the stabilization of ORR intermediates *O or *OH. Within van der Waals functionals, the highest stabilization is observed for 0.33 ML *O in agreement with the low adsorption free energy associated with the formation of the next immediate stable 0.33 ML *OH coverage. Among these, rPW86 shows much earlier oxidation of Pt(111) surface at a pH of 6.5 with the formation of 0.33 ML *OH covered surface along with a higher stable potential window for *OH covered state. Since the most stable surface state under ORR relevant potentials and pH range are predicted uniformly in spite of the differences in the relative stabilities with different methods, we envision that a common theoretical framework can be employed to analyze the energetics and kinetics of ORR. Witnessing the different energetics associated with the adsorption of intermediates predicted by different DFT methods, we attempt to scrutinize the role of dispersion effects in determining the overall ORR activity on Pt(111) surface. We have considered a reaction network proposed by Hansen et al. where the intermediates involved in the elementary steps occupy the water adsorbed sites as well as interstitial sites (Scheme 2). These include *O2_S1, *O_S2, *O_S2, *OH_S1, *OH_S2, *OOH_S1, *H2O_S1, *H2O2_S1 where S1 and S2 represent the platinum surface site bound by water molecules in the BL and the interstitial sites, respectively. The reaction network includes the diffusion of molecular O2 from bulk electrolyte (O2(aq)) to the electrode-electrolyte double layer region at the electrode (O2(dl)) followed by adsorption on the catalyst surface (*O2). From this state, five further pathways are investigated by using the adapted reaction network i) For pathways involving similar steps, only unique steps are labeled.