with j 0 0 the exchange current density at a standard reference pressure of p ⊖ = 1 bar, the reaction order γ of the exchange current density with respect to p H2 defines the slope of the double-logarithmic plot of j 0 vs. p H2 , shown in Fig. . We obtained a value of γ = 0.65±0.05, which is very close to the result reported by Rheinländer et al. (γ = 0.61) following the same sort of micropolarization analysis. The respective fitted value of the prefactor was