Co-permeation of deuterium and hydrogen through Pd

Experiments on permeation of deuterium through a palladium membrane, which was accompanied by co-permeation of hydrogen, were performed in the pressure range below 1 Pa. Permeation of deuterium exhibited features of surface limited regime (SLR) both with and without hydrogen co-existence. Release of D-2, HD, and H-2 molecules from the downstream side of the membrane was observed in presence of hydrogen. No visible blocking of deuterium permeation by hydrogen appeared. The net permeation rate of deuterons in D-2 and HD forms in the co-permeation experiments with hydrogen was found to be approximately the same as in the experiments without hydrogen, if the effective deuterium pressure p(D-2) + p(HD)/2 remained the same irrespective of the partial pressure of hydrogen p(H-2). The experimental data were described by a steady-state permeation model, which took into account D-2, HD, and H-2 absorption and desorption. (C) 2001 Published by Elsevier Science B.V.