Templated and Ordered Mesoporous Carbons

Abstract

Crystalline aluminosilicate zeolites are prepared via a hydrothermal synthesis using a silica source, in the presence of a small quaternary ammonium molecule. Microporous carbons have been prepared as inverse replicas of zeolites. Dispersed colloidal silica particles of various sizes and colloidal silica crystals have been used as templates of porous carbons, with spherical pores having narrow pore size distributions. By coating monodisperse colloidal silica particles or crystals with a suitable carbon precursor, followed by carbonization and etching of the silica, porous carbon particles can be obtained. Monoliths can be prepared from powder processing using polymeric binders and additional carbonization stages. Precise control over particle size and morphology is needed to successfully prepare a monolith. Contrary to colloidal silica templating where the pore size is determined by the diameter of the silica colloids used, the pore widths of the hard-templated ordered mesoporous carbons depend on the pore wall thickness of the selected ordered mesoporous silica template.