Preparation and structure characterization of carbons prepared from resorcinol-formaldehyde resin by CO2 activation

Abstract

In this work, carbon xerogels with a high pore volume and surface area (up to 2.58 cm3/g and 3200 m2/g respectively) have been synthesized using the sol-gel polycondensation of resorcinol (R) with formaldehyde (F) in a basic medium of monoethanolamine (MEA), followed by drying and pyrolysis. This medium (MEA) has not been used in previous investigations. The effect of activation with CO2 on the pore size distribution and the chemical functional groups has been investigated using N2 (77 K) adsorption, FTIR and elemental analysis techniques. A series of experiments has been conducted to investigate the effect of activation time and activation temperature. Activation of the samples was carried out at 850, 900 and 980 °C for times ranging from one to three hours. Within the range of activation conditions, an increase in activation time at 850 °C results in a continuous steady rise of the BET surface area and total pore volume. However, at the two higher temperatures, the surface area shows a maximum when plotted against activation time. FT-IR results show that the use of MEA as a catalyst leads to the formation of nitrogen functional groups in the surface of the resin.