Patent ID: 8119205

Claim:
A method for making a palladium alloy composite membrane consisting of: seeding at least a portion of an asymmetric porous substrate for supporting a palladium alloy film with palladium crystallites to produce an activated surface, wherein said porous substrate has a pore size gradient in a range of between 20 nm to 50 nm and a pore size adjacent to said porous substrate for supporting said palladium alloy film of between about 50 nm and 5 nm; first plating, over said activated surface, a palladium film; second plating, over said palladium film, an alloying material, wherein said alloying material is gold; and annealing said porous substrate, said palladium film, and said alloying material so that there is intermetallic diffusion of said alloying material into said palladium film to produce said palladium alloy film over said porous substrate.