The values obtained from this statistical model have subsequently been confronted with numerous literature data  reported in Table 3. Results depicted in Figure 2a–c show that the model accurately predicts the literature values of H/Pd, H/Ir, and H/Rh, respectively. In addition, the model predicts H/M values in the range 0–1.08 for Pd, 0–2.77 for Ir, and 0–2.31 for Rh. The latter result clearly indicates that a single stoichiometry for Pd, Ir, and Rh cannot be used.