The present invention provides composite membranes consisting of palladium and palladium alloys with a phosphorus component. The membranes may be used in a tubular geometry on an alumina support. In other embodiments, the membranes may be prepared by treating the metal precursor with a phosphorus source such as phosphine.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH & DEVELOPMENT
 This invention was made with government support under DE-FG02-96ER14669 awarded by the Department of Energy. The government has certain rights in the invention.