Metal gas separation membrane

An improved metal gas separation membrane for separating hydrogen from a gas steam includes a quantity of metal particles that are bonded together to form a porous body that is selectively permeable to hydrogen. The porous body may have a porosity that increases from a first surface to an opposite second surface. The metal gas separation membrane may additionally include a coating of ceramic particles on the first surface thereof to further decrease the porosity at the first surface. Alternatively, or in addition thereto, the metal gas separation membrane may include a thin foil or coating of a dense precious metal such as palladium, palladium-alloys, and the like applied thereto that is permeable by hydrogen according to a chemisorption-dissociation-diffusion transport phenomenon. Still alternatively, or in addition thereto, the porous body may include a catalytic enhancement that can interact with a gas stream to increase the concentration of hydrogen according to various catalytic reactions such as the water gas shift reaction and the ammonia decomposition reaction.