Activated carbons with well-developed microporosity prepared from Phragmites australis by potassium silicate activation

Potassium silicate (K2SiO3) was employed as new activating agent for preparing activated carbons with well-developed microporous structure from a renewable source (Phragmites australis, PA). The effects of chemical impregnation ratio (mass of K2SiO3: PA, 1.0-2.5) and activation temperature (450-800 degrees C) on the properties of activated carbons were investigated. Porous textures and surface morphologies of the carbons were characterized by N-2 adsorption/desorption and scanning electron microscopy (SEM). The activation was simulated by thermo-gravimetric analysis. In general, under the experimental conditions investigated, the highest surface area (721 m(2)/g) of activated carbons reached at activation temperature of 600 degrees C and impregnation ratio of 1.5. The produced carbons were mainly microporous and the majority of pore widths of the carbons were below 4 nm. These results indicated that K2SiO3 could be used as a new activating agent to produce activated carbon. (C) 2014 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.