Dependence of hydrogen flux on the pore size and plating surface topology of asymmetric Pd-porous stainless steel membranes Original Research Article

The influence of the support properties on the characteristics of Pd/PSS composite membranes has been evaluated for a large group of membrane samples prepared by electroless plating. The H2 permeation in the membranes was found to follow Sievertʹs law between 325–500°C. The steady state H2 flux was stable for over 200 h. The hydrogen permeance was measured at 350°C with a 1-atm pressure difference and ranged from 20.0 to 5.1 m3/(m2·h·atm0.5) for a Pd layer thickness of 11.7 and 33.8 μm, respectively. The thickness of the membranes and therefore the permeance obtained was dependent on the size of the largest pores present in the support. The thickness of the Pd layer was approximately three times the dimension of the largest pores in the support, consistent with the previous theoretical results of Ma et al. [3].