Protonation of O2 adsorbed on a Pt3 island supported on transition metal surfaces.
The reduction in oxygen on bimetallic tips X(S)Pt(3) (X(S) = Co(3), Ni(3), Pt(6), Co(3)Pt(3)) in aqueous acid medium is studied. It is found that a locally neutral neighborhood of an active site in the bimetallic tip as well as adduct hydration assist in the protonation. It is concluded that metallic tips of Pt, Co(3)Pt, and Co are comparable in performance for the oxygen reduction reaction. For an adduct, the larger the bonding energy of the Pt(3)-island to the (X(S)) substrate, the more charged the oxygen molecule becomes for different levels of protonation. Furthermore, if a hydroxyl OOH group is formed as a result of protonation, the interaction of the cation with O(2) decreases with increasing level of hydration.
Sotelo
Juan C
JC
Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843-3122, USA.
Seminario
Jorge M
JM