Potentiometric Titrations: Characterize Functional Groups andAdsorbed Species on Activated Carbon

摘要

Potentiometric titrations characterized acid and base functional groups on conventional and thermally tailored activated carbons.rnThese titrations also characterized aqueous-phase benzoic acid as compared to an activated carbon that had been preloaded withrnbenzoic acid. The potentiometric titration data was converted into proton affinity distributions so as to discern functional groups.rnThese were compared with Boehm titrations and IR spectra. The three protocols revealed some consistencies, but also somerndistinctions. Relative to benzoic acid, it was observed that the activated carbon surface influenced both the shape of titration curvesrnand pKa position. When benzoic acid was adsorbed, its proton affinity was dampened, and the measured pKa moved upward.