Catalyst Deposition in Porous Membranes

Catalytic membranes can be prepared by deposition of a catalytically active phase (e.g., a metal) in the inert porous membranes through various techniques commonly used for conventional catalyst preparation - such as wet impregnation, monolayer metal complexation, and ion exchange -followed by heat treatment (activation) [17], The conventional activation steps can also be avoided by direct deposition of solvated metal microclusters [21], The structural characteristics of the porous substrate, and in particular the relative laminar and Knudsen contributions to permeation, have a strong influence on the membrane performance [22], They make use of the membrane structure to optimize the access of disfavored reactants, or to control and rule the residence time and contact of species in the active zone. Furthermore, the porous membrane is required to present a rather homogeneous structure to avoid heterogeneities in the reactant-to-catalyst contact, and also to facilitate CMR operation control. 

EiWre 2 12 chematic diagram of the y-AhOj/a-AhOs bimodal supported catalytic Composition. R.p.oduced from 23]. With pomtission 

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