Preparation of a pitch-based activated carbon with a high specific surface area

Pitch based activated carbons (PAC) with a high specific surface area were produced by a direct chemical activation route in which oxidative stabilized pitch derived from ethylene tar oil was reacted with potassium hydroxide under various activation conditions. it was found that PACs with a surface area of around 2600-3600 m(2)g(-1) could be obtained under suitable activation conditions. N-2 adsorption (at 77 K) and X-ray photoelectron spectroscopy experiments showed that the PAC has a uniformly developed micropore structure and a narrow pore size distribution (radius 0.8-1.6 nm). Abundant oxygen-containing functional groups (such as C-OH, C-O-C, C=O, COOR etc.) were found to exist on its surface. Compared with a commercially available activated carbon (AC) and also a pitch based activated carbon fibre, PAC has a quicker adsorption-desorption velocity and a larger adsorptive capacity to benzene due to its higher surface area. Clear surface differences between PAC and AC were observed by transmission electron microscopy.