Since *O adsorption has been identified to largely disrupting the BL, gas phase coverage simulations are applied for *O. We construct surface Pourbaix diagrams to understand the most stable surface state and the trends in relative stability between different surface states. The considered coverages are 0.11 ML, 0.22 ML and 0.33 ML for both the *O and *OH species. It is to be noted that this does not cover the entire coverage range possible for these intermediates to have on Pt(111) surface. However, we are constrained to these coverages in tandem with the objective to understand the role of dispersion interactions in predicting the relative stability of different surface states rather than identifying the most stable state precisely with each method.