Surface Atoms in Acid Medium

The most important distances for all the cases in Fig. 17 and others are listed in Table 8. It is observed that OH canses a larger snrface buckling of the Pt atoms (up to 1.26 A above the surface plane) in comparison with the oxygen effect. This is in agreement with recent discussions about the role of OH product of water oxidation on the catalyst surfaces at high positive potentials.  

Analyses of the calculated minimum energy paths for migration of oxygen from the surface into the snbsnrface of Pt(l 11) provide a plausible explanation to the experimentally detected difference in measined amounts of dissolved platinnm in electrochemical experiments using platinnm electrodes in acid medinm at con- 

Interlayer Distanee (du, in A) between 1 and I Layers, and Pt-Pt Buekling Distanee between tbe Plane of tbe Surfaee Atoms and the Highest Pt Atom after Reeonstmetion (in A) for Varions O and OH Snrfaee and O Snbsnrfaee Coverage Expressed in Fraetions of 1 ML. 

O surface coverage 0 subsurface coverage OH surface coverage di2 Pt-Pt buckling 

The next question is how the migration process of oxygen into the snbsnrfaee may be altered by the presence of other metals. We fonnd that depending on the nature of the element added to pure Pt, transition metals (Co, Ni, Ru, Rh, Pd, and Ir) can influence the magnitndes of the O surface diffusion, absorption, and reverse 

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