High-flux H2 separation membranes from (Pd/Au)n nanolayers

A novel strategy for the preparation of supported PdAu alloy layers allows the facile and fast fabrication of highly permeable and selective H2 separation membranes from refractory metals via electroless plating and low-temperature alloying. Homogenous alloying of multiple, separately deposited Pd and Au layers with thickness in the nm range required less than one week at 773 K under atmospheric H2 as evidenced by X-ray diffraction and H2 permeation measurements. The H2 permeation rate J H 2 became stable within a day even, reaching 0.62 mol m−2 s−1 at 773 K and Δ P H 2  = 100 kPa. The corresponding N2 leak rate remained constant during a 350 h experiment, resulting in an ideal H2/N2 selectivity of 1400 and demonstrating that such membranes tolerate extended operation at that temperature well.