Adsorption of dibenzothiophene by copper- and copper oxideimpregnated activated carbon fibers

Three types of copper-impregnated activated carbon fibers (ACF) were prepared by impregnation of a commercial ACF with Cu(NO3)2.3H2O using an incipeint wetness method followed by calcination at 325, 375, or 595 oC under a nitrogen atmosphere. Samples prepared at different temperatures contained Cu, CuO, or Cu2O species. The total copper content and the crystalline structure of loaded copper species were determined by atomic absorption spectroscopy and X-ray diffraction, respectively. Adsorption isotherms of dibenzothiophene (DBT) from a simulated simple fuel (DBT dissolved in n-hexane) by original and copper-loaded fibers were measured at room temperature. Cu2O-loaded ACF showed a significantly higher DBT uptake compared to ACF samples loaded with Cu and CuO and the ACF sorbent. Enhanced adsorption of DBT by Cu2O-loaded ACF was expalained based on the hard/soft acid and base theory.