title: Effect of KOH activation on the formation of oxygen structure in activated carbons synthesized from polymeric precursor.
abstract: In this work, the influence of KOH activation on the surface chemistry of activated carbons (ACs) synthesized from polystyrene-based cation exchangeable resin (PSI) has been investigated. The surface chemistry of ACs has been characterized by using Fourier transformed infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), pH measurement, and Boehm's titration method. As a result, PSI can be successfully converted into ACs with high porosities. The total oxygen content on the ACs studied increases with increasing the KOH-to-PSI ratio. FT-IR and XPS analyses show that the resulting carbons possess a number of oxygen surface functional groups, such as carbonyl, quinone, phenol, ether, and carboxylic acid groups. The highest oxygen content and acid value are observed at a KOH-to-PSI ratio of 4 (KPS-4). However, its pH and surface basicity are higher than those of a KOH-to-PSI ratio of 2 (KPS-2), indicating the formation of basic species, such as quinone and pyrone groups. Although the oxygen-containing groups with basic character exist in the resulting carbons, all the samples are still acidic in character.
authors.affiliation: Advanced Materials Division, Korea Research Institute of Chemical Technology, P.O. Box 107, Yusong, Taejon, 305-600, Korea. psjin@pado.krict.re.kr
authors.forename: Soo-Jin
authors.initials: SJ
authors.lastname: Park
authors.forename: Woo-Young
authors.initials: WY
authors.lastname: Jung