Heterogeneous mesoporous oxides grown in porous anodic alumina

Heterogeneous mesoporous oxide structures consisting of adjacent domains of mesoporous titania and silica (TiO2/SiO2) were synthesized by sequential deposition into the pores of a porous anodic aluminum oxide (AAO) support. Each anodic alumina macropore contained distinct mesoporous structural domains corresponding to the two oxide structures. Transmission electron microscopy imaging showed that the titania and silica regions contained organized pores with diameters of ∼8–10 nm and ∼13–16 nm, respectively. Nitrogen adsorption measurements showed a typical Type IV behavior characteristic of mesoporous materials. The surface area for the heterogeneous composites ranged between ∼75 and ∼100 m2/g. Gas permeability measurements of the samples indicated complete filling of the AAO support by the mesoporous TiO2/SiO2 regions. Preliminary results regarding the possibility of extending this method to mesoporous ZrO2/SiO2 compositions are also presented.