Mesoporous carbon confined conversion of silica nanoparticles into zeolite nanocrystals

A novel synthesis method has been developed to synthesize zeolite nanocrystals with controllable size and size distribution through conversion of colloidal silica nanoparticles in a mesoporous carbon matrix. Colloidal silica nanoparticles serving as the silica source as well as the hard template were embedded in the mesoporous carbon via in situ polymerization of furfuryl alcohol in the presence of tri-block copolymer (Pluronic P123), and then reacted with an alkaline aqueous solution (Na₂O–Al₂O₃–H₂O) infiltrated through the mesoporous channels of the carbon matrix. The synthesis of zeolite NaA nanocrystals is demonstrated. SEM images reveal that the sizes of the zeolite NaA nanocrystals obtained are similar to those of the starting silica nanoparticles. As a result, this synthesis method shows the potential for controlling the nanocrystal size and size distribution of silica-containing zeolites by choosing colloidal silica nanoparticles with a desired particle size distribution.