Jerry Y. S. Lin, Department of Chemical and Materials Engineering, Arizona State University, Tempe, AZ 85287 and Ke Zhang, Dept of Chemical Engineering, Arizona State University, Tempe, AZ 85260.
Thin palladium membranes are synthesized on mesoporous ã-alumina/á-alumina and yttria stabilized zirconia (YSZ)/á-alumina composite supports by sputter deposition and electroless plating method. The effect of metal-substrate interaction on H2 permeation was investigated by comparing H2 fluxes through the Pd/γ-alumina/α-alumina and Pd/YSZ/α-alumina supprots in 633-713K. H2 fluxes through Pd/γ-alumina/α-alumina are lower than those through Pd/YSZ/α-alumina membrane of the same thickness under the same conditions. The permeation data are analyzed by a model considering hydrogen diffusion in the bulk of the Pd layer and surface reaction at the metal-support interface. The Pd-alumina interface provides much higher surface reaction resistance for hydrogen permeation than the Pd-zirconia interface due to formation of Pd-Al alloy at the Pd-alumina interface. The results show the importance of the selection of a chemically inert material as the support for thin metal membranes.