NOVELTY - Inorganic membrane structure comprises an inorganic porous support comprising a first end, a second end, and a many of inner channels having surfaces defined by porous walls and extending through the support from the first end to the second end; one or more porous intermediate layers comprising inorganic particles coating the inner channel surfaces of the inorganic porous support; and a zeolite membrane comprising a zeolite seed layer coating the remaining surface of the one or more porous intermediate layers and a zeolite intergrown layer coating the zeolite seed layer.    USE - The inorganic membrane structure is useful for molecular-level separation, filtration and separation applications in the environmental, biological, food and drink, semiconductor, chemical, petrochemical, gas and energy industries, for separation in processing industries with enhanced energy and capital efficiency, e.g. carbon dioxide capture from flue gas streams for sequestration, hydrogen (H2) recovery from waste gas streams, hydrogen (H2) purification from a production gas mixture for fuel cells application and water removal from ethanol/water mixtures in biomass conversion processes.    ADVANTAGE - The inorganic membrane structures has high stability, high permeability, and large surface area.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) a method for reducing carbon dioxide content of a gas stream, comprising introducing a feed gas comprising carbon dioxide into the first end of the inorganic membrane structure and collecting a retentate gas stream lower in carbon dioxide content than the feed gas from the second end of the inorganic membrane structure; and    (2) a preparation of the inorganic membrane structure, comprising providing the inorganic porous support comprising first end, second end, and many of inner channels having surfaces defined by porous walls and extending through the support from the first end to the second end; applying one or more porous intermediate layers comprising inorganic particles to the inner channel surfaces of the inorganic porous support; applying the zeolite seed layer to the one or more porous intermediate layers; and hydrothermally growing a zeolite intergrown layer from the zeolite seed layer.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic representation of the inorganic membrane structure.    Inorganic porous support (2)    First end (4)    Second end (6)    Inner channels (8)    Inner channel surface (10)    Inorganic membrane structure. (100)