The invention provides support-free palladium membranes and methods of making these membranes. Single-gas testing of the unsupported foils produced hydrogen permeabilities equivalent to thicker membranes produced by cold-rolling. Defect-free films as thin as 7.2 microns can be fabricated, with ideal H.sub.2/N.sub.2 selectivities as high as 40,000. Homogeneous membrane compositions may also be produced using these methods.
This invention was made with Government support under grant number DE-FG26-03NT41792 awarded by the U.S. Department of Energy's NETL University Coal Research Program and grant number DE-GF03-93ER14363 awarded by the U.S. Department of Energy's Office of Science, division of Basic Energy Sciences. The Government has certain rights in this invention.