Synthesis and Characterization of a ZrO2/AC Composite as a Novel Adsorbent for Dibenzothiophene

Zirconium dioxide was impregnated into a commercial activated carbon (AC) by hydrothermal treatment employing an aqueous ZrOCl2 center dot 8H(2)O solution. The ZrO2/AC composites thus prepared were tested as adsorbents for dibenzothiophene (DBT) from a model diesel fuel. In comparison to the pure AC, impregnation of ZrO2 was found to lead to a ca. 17% increase in the adsorption capacity. The optimal ZrO2 loading and hydrothermal pH were determined as 0.1 mmol/g and 7, respectively. The spent adsorbents were regenerated by toluene washing, with the ZrO2/AC composite exhibiting a higher adsorptive capacity than pure AC even after three such recycles. The ZrO2/AC composite was also characterized by the physical adsorption of nitrogen and Boehm titrations. The results indicated that surface acidic sites on the impregnated ZrO2 may play an important role in the improved desulphurization performance of the composite.