Low-temperature H2 and N2 transport through thin Pd66Cu34Hx layers

The single gas H2 and N2 permeability of a 4 μm thick dense fcc-Pd66Cu34 layer has been studied between room temperature and 510 °C and at pressure differences up to 400 kPa. Above 50 °C the H2 flux exhibits an Arrhenius-type temperature dependence with JH2=(5.2±0.3) mol m−2 s−1 exp[(−21.3 ± 0.2) kJ mol−1/(R·T)]. The hydrogen transport rate is controlled by the bulk diffusion although the pressure dependence of the H2 flux deviates slightly from Sieverts' law. A sudden increase of the H2 flux below 50 °C is attributed to embrittlement.