High Molecular Permeance in a Poreless Ceramic Membrane


  • Support of this work came from National Science Foundation (CTS-0622666) and ConocoPhillips Inc. is gratefully acknowledged.


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A novel composite membrane without continuous pores (see figure) with very high permeance for hydrogen is reported. The membrane is composed of a thin (30 nm) permselective silica layer deposited on a graded γ-alumina multilayer substrate, consisting of size-controlled boehmite (AlOOH) sols deposited in order of decreasing size on a macroporous alumina support. A theory involving jumps of permeating molecules between adjacent solubility sites explains its behavior.