Templateassisted selfassembly of macro–micro bifunctional porous materials

Abstract

The preparation of macro–micro bifunctional porous materials has been accomplished by a well-controlled, vacuum-assisted technique. Monodisperse polystyrene latex spheres were ordered into close-packed arrays by slow sedimentation, allowing a high flux of water through the interstices between latex spheres. Zeolite LTA, FAU, LTL, BEA, MFI and Si-MFI nanocrystals, synthesized by hydrothermal procedures, permeated the interstices of latex spheres under the driving force of flowing water. After drying and calcination at 500 °C, both the latex spheres and zeolite structure-directing molecules were removed, followed by the formation of products consisting of both crystalline micropores and periodic, interconnected networks of submicron macropores. XRD, SEM, TEM, IR, TG/DTA, ICP and N2 adsorption–desorption measurements were performed to monitor the preparation and to characterize the properties of the macro–micro bifunctional porous materials. The materials presented in this paper combine the benefits of both the micropore and macropore regimes. They could potentially improve the efficiency of both separation and catalysis of zeolites.