Preparation of hollow zeolite spheres and three-dimensionally ordered macroporous zeolite monoliths with functionalized interiors

A novel and flexible strategy involving hydrothermal transformation of guest-incorporated zeolite-seeded mesoporous silica spheres was proposed to prepare guest-encapsulated hollow zeolite spheres and three-dimensionally (3D) ordered macroporous zeolite monoliths. The guest species that were pre-incorporated into the mesopores of silica spheres could be spontaneously encapsulated inside the formed hollow zeolite shells by consuming silica nutrition of the original mesoporous silica cores during the hydrothermal process. A wide range of guest materials with a size ranging from nanometers to micrometers, e.g., Ag and PdO nanoparticles, and mesoporous spheres of carbon and polymer of micrometer size were successfully encapsulated into both discrete hollow zeolite spheres and 3D ordered macroporous zeolite monoliths. Such materials are expected to find a variety of applications such as catalysis, adsorption, and novel microreactors for their special structures with active species inside and zeolitic porous shell outside.