By using a sensitive electrochemical technique, it was deduced that diffusion of H at temperatures ranging from 27 to 60C was governed by an activation energy of 4.2kcal/g-atom.

The Electro-Permeation of Hydrogen into Metals. J.O.Bockris, M.A.Genshaw, M.Fullenwider: Electrochimica Acta, 1970, 15[1], 47-60