The coverage is then calculated as the ratio of these two atomic counts. At low pressures, our results compare relatively well with the study of Gai et al. which was done at a lower temperature on a Pt(111) surface. Discrepancies between our results and Pt(111) surface widen when considering the experimental study of Getman et al. where a coverage of 0.48 was reported at a pressure of 10 -4 atm and a temperature of 353K. A restriction on coverage is identified by the authors to be due to kinetic limitations of O 2 , which becomes less favorable as the oxygen coverage increases. When switching to NO 2 , a kinetically favorable oxidant, the authors found a coverage of 0.75 ML, closer to our results. We note that our results are not completely comparable to clean surface studies since our nanoparticle has a different surface area and different binding sites and should generally display slightly higher coverages due to stronger binding on a nanoparticle of this size. Finally, our simulations systematically display a lower oxygen ratio than the studies of Kirchhoff et al. at similar pressures and temperatures. We attribute it to our methodology which differs from the Monte Carlo minimization scheme used in these studies. This minimization scheme includes a full geometry relaxation carried before the acceptance criteria, ultimately leading to faster convergence and higher oxygen ratio, but does not correctly sample the canonical ensemble and resembles more a basin-hopping algorithm. Additionally, our current hybrid MC-MD methodology was not driven by the need to reach specific coverages, but to also include the dynamics of the platinum atoms, to potentially discover interesting geometrical features that might be amplified by including the dynamics. Finally, above our highest oxygen ratio addition moves mainly lead to the formation of O 2 due to saturation, which is less relevant for this study.