In a previous work , we demonstrated that the multiple adsorption assumption is consistent with the H2 chemisorption literature data for the Pt catalysts . For this purpose, a model describing the statistics of the surface atoms and sites (top, bridge, hollow) on perfect cuboctahedron clusters was developed. This model allowed us to assess values of D(%), d and SPt, assuming the most favorable adsorption sites based on DFT calculation from the literature . Thus, it successfully predicted, precisely, the H/PtS stoichiometry, which ranges from 1 to 2 for the smallest cluster (dPt = 0.7 nm), and the experimental values of D, d, and SPt determined from H2 chemisorption data. A set of simple equations was provided for the accurate determination of these parameters from chemisorption experiments on Pt. This approach, based on the combination of identification and quantification of adsorption sites for a given cluster shape, is expected to be valid for other fcc metals, such as Pd, Rh, and Ir.