Equations (6)–(8) can be generalized by the following single equation (Equation (11)): (11)YM=aY×(HM)5+bY×(HM)4+cY×(HM)3+dY×(HM)2+eY×(HM) where aY,bY,cY,dY, and eY are constants depending on the nature of the metal M considered (where M = Pd, Rh, or Ir). The values of these empirical constants for Equation (11) are listed in Table 4.