Preparation of Membrane Catalyst

For those cases where the catalyst is not attached to the membrane, catalyst pellets are typically used. The preparation of catalyst pellets has been extensively documented and will not be reviewed here. Only the preparation of the catalyst inside the membrane porous structure is discussed in this chapter. 

Given the relatively limited surface area available for catalyst on the surface of the membrane or its pores, a high catalyst surface area can be achieved with minimum catalyst loading by applying a very fine dispersion of catalyst particles. Dispersion of the catalyst particles affects the reaction kinetics and selectivity. 

Two methods have been adopted for preparing catalysts for the membrane reactors impregnation and ion exchange. The former method has been predominantly used when attaching catalysts to membranes. 

Shown in Table 9.7 are some examples of incorporating catalysts into porous ceramic membranes. Both metal and oxide catalysts have been introduced to a variety of ceramic membranes (e.g., alumina, silica, Vycor glass and titania) to make them catalytically active. The impregnation/heat U eatment procedures do not appear to show a consistent cause-and-effeci relationship with the resulting membrane permeability. For example, no noticeable change is observed when platinum is impregnated into porous Vycor glass 

Catalyst Impregnation solution Membrane material Reference 

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