Boundary conditions during the electrochemical diffusion of H through α-Pd were considered. During permeation experiments, variations in the electrode potential and current density at the cathode surface were found to correspond to those in the dissolved H content and H entry flux at the cathode surface, respectively. The diffusivity of H at temperatures of between 278 and 333K was determined by using potentiostatic step-charging and step-stripping methods (figure 28), and was found to be described by:

D (m2/s) = 2.40 x 10-7 exp[-21.6(kJ/mol)/RT]

Boundary Conditions in Electrochemical Measurements of Diffusion Coefficients of Hydrogen in α-Palladium. H.Hagi: Materials Transactions, 1990, 31[10], 842-7