Adsorption Properties of Micro-/Meso-porous Carbons Obtained byColloidal Templating and Post-synthesis KOH Activations

摘要

Nitrogen adsorption studies have been employed to examine thestructural properties of micro-/meso-porous carbons obtained by colloidaltemplating and post-synthesis KOH activation. These carbons were prepared bypolymerizing phenol and formaldehyde in the pores of a colloidal silica templatefollowed by carbonization, silica dissolution and post-synthesis KOH activation.Colloidal silica was used to create spherical mesopores, while KOH activation wasperformed to create additional microporosity and to enlarge the surface area of theresulting carbons. Nitrogen adsorption studies showed that a single impregnationof the colloidal silica template with phenolic resin precursors afforded carbonswith relatively thin pore walls which did not withstand the post-synthesis KOHactivation; however, a double impregnation generated mesoporous carbons withthicker pore walls. Activation of these latter carbons with KOH created microporesin the mesopore walls without significant deterioration of the mesopore structure.The resulting mesoporous carbons possessed high specific surface areas (ca. 800m~2/g) and large single-point pore volumes (ca. 1.8 cm~3/g). The post-synthesisKOH activation enlarged the surface area up to 1500 m~2/g, which was achievedvia the creation of microporosity. Hence, the carbon obtained by doubleimpregnation and activation exhibited a single-point pore volume of ca. 2 cm~3/gwith a relatively high microporosity which attained 17% of the total porosity.High-surface-area micro-/meso-porous carbons are attractive for adsorption,catalysis and energy-related applications such as capacitors and batteries.