Erik E. Engwall

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

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 Sieverts 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].

Thin Composite Palladium and Palladium/Alloy Membranes for Hydrogen Separation

Abstract: Dense composite Pd and Pd/alloy membranes are currently being extensively investigated. The synthesis and characterization of these membranes, with a special emphasis on Pd/alloy membranes, are reviewed in this paper. Experimental results on Pd/Cu membranes supported on porous stainless steel exhibited good thermal stability and reasonable hydrogen flux. Furthermore, optical micrographs showed the formation of the dense palladium layer was unaffected by the topological features of the porous stainless steel, although the surface of the support directs the topology of the final Pd layer.