Density functional theory study of adsorption of OOH on Pt-based bimetallic clusters alloyed with Cr, Co, and Ni

The adsorption of OOH, the main product of the first step in the O2 reduction on Pt(1 1 1) surfaces, is studied on Pt-based bimetallic three-atom clusters. Cr, Co, and Ni are better adsorption sites for OOH than Pt, but the strong adsorption might not favor the dissociation of OOH. However, the presence of Cr, Co, or Ni in the vicinity of a Pt atom increases its electron density, enhancing the Pt ability to transfer electrons to oxygenated species. Thus, Cr, Co, or Ni in the subsurface, rather than on the exposed surface, may contribute favorably to catalyze the O2 reduction.