Both melamine modification and alloying activate ORR by destabilizing OH*. However, the mechanisms by which OH* is destabilized are completely different between the two surfaces. As shown in the projected density of states (PDOS) in Fig. , the d-band of the Pt atom located directly beneath the melamine is downshifted in energy. This trend qualitatively matches the previously reported shifts in the d-band of surface Pt atoms with organic molecules. However, it is evident that OH cannot adsorb onto the Pt atom directly beneath the melamine. As shown in Fig. , the changes in the electronic structure caused by melamine are highly localized. Furthermore, as demonstrated in Fig. (a), the PDOS of the d-band for the surface Pt atom, where OH is stably adsorbed during finitetemperature MD, closely matches that of a surface Pt atom without melamine, indicating that the modification of the d-band by melamine is minimal. The shift in the d-band center of the OH-adsorption site is only 8 meV, which is orders of magnitude smaller than the downshifts of 200 to 300 meV observed in Pt alloys containing Ni and Co in previous studies. The localized nature of the electronic effect of melamine is also reflected in the Bader charge analysis (see also Fig. ). The Pt atom directly beneath the melamine, bonded to the N atoms in melamine, is positively charged due to electron withdrawal by melamine, while the charge on the nearest Pt atom closely matches that of a Pt surface without melamine. These results suggest that the destabilization of OH* is not due to a downshift in the d-band. Furthermore, as shown in Fig. (b), unlike the alloyed Pt surface containing Cu, which was also calculated in this study, melamine does not alter the distance (d) between the surface and subsurface layers. On the Pt-Cu alloys, the shortening of the metal-metal distance leads to the destabilization of the OH adsorbate via the strain effect, but these results indicate that the destabilization caused by melamine is not due to the strain effect. The difference in the mechanism is also evident in the shift in the calculated redox potential (∆U OH ) relative to the pure Pt(111) surface in vacuum, as shown in Fig. ). On alloyed surfaces, the positive shift occurs even in a vacuum, whereas on the Pt surface with melamine, the positive shift is observed only in water. This significant red shift is attributed to strong hydrogen bonds between interfacial water molecules and the OH adsorbate. In contrast, on the Pt surface with melamine, the O-D stretching band is instead blue-shifted, and the red-shifted band diminishes. This indicates that melamine weakens the hydrogen bonds. The mechanism by which OH* is destabilized and ORR is accelerated due to the disruption of the solvation structure around OH* has been proposed to occur through the introduction of one-dimensional step defects or hydrophobic cations on the Pt(111) crystal surface. The results of this calculation indicate that melamine promotes ORR through the same mechanism.