Enhanced selective catalytic oxidation of H2S over Ce-Fe/AC catalysts at ambient temperature

In this study, we prepared a new-type Ce-Fe impregnated activated carbon (AC) catalyst for the catalytic oxidation of H2S to S at room temperature. Characterization of the Ce-Fe/AC catalysts and the corresponding catalytic activity for H2S removal were analyzed and evaluated. The Ce impregnation not only significantly increases catalytic activity but also decreases O-2 demand for H2S removal due to the oxidation of Fe2+ to Fe3+ improved by the redox couple Ce4+/Ce3+. The Ce incorporation significantly improved on sulfur capacity and breakthrough time. The breakthrough time and sulfur capacity of the AC supported Ce-Fe catalyst tested under a relative humidity of 80% and 10% O-2 atmosphere at room temperature can reach to 71 h and 820 mg Sig cat, respectively, being much higher than that of the alkaline impregnated AC. It was found that the formed sulfur mainly deposited inside the pore of the AC, but some also formed on the surface of the AC. The activity enhanced by impregnating Ce mainly arises from the increase of chemical potential and the reduction of surface contaminants. (C) 2020 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.