Synthesis of silicalite-1 using an interspace of ordered mesoporous carbon−silica nanocomposites: Introduction of mesoporosity in zeolite crystals

Silicalite-1 zeolite crystals with mesoporosity were prepared by hydrothermal synthesis mediated by structure-directing agents (SDA) using mesoporous carbon−silica nanocomposites as starting materials. These materials have ordered structures with channel mesopores and mesochannel walls made up of carbon and silica. The growth of zeolite crystals took place inside the open mesospace without the collapse of the ordered mesostructure during hydrothermal synthesis at optimized molar ratios of tetrapropylammonium hydroxide and bromide. The disordered mesoporosity, which slightly persisted as a vestige of channel structure, was introduced into the zeolite crystals even after the removal of the carbon part of the framework, though a small amount of amorphous silica was remained.