In this paper we describe a composite-metal membrane that shows promise for practical large-scale applications including the manufacture of ethylene, recovery of hydrogen from refinery streams, and the environmentally clean decomposition of hydrogen sulfide in sour natural gas and refinery off-gases. Specifically, this composite membrane exhibits improvements over previously developed metal membranes that include (1) stable hydrogen flux at 700-degrees-C, (2) low cost and (3) chemical compatibility with many common feed-stream impurities, including hydrogen sulfide.