Catalytic activity of a ceria-supported Iridium (Ir/CeO(2)) catalyst was investigated for steam reforming of ethanol within a temperature range of 300-500 degrees C. Three types of ceria were chosen to prepare the catalyst: commercial [assigned as CeO(2)(C)] and prepared [using a simple reduction-oxidation method, CeO(2)(R), and another combined with ultrasonic irradiation, CeO(2)(U)] ceria. The Ir/CeO(2) catalyst with Ir loading of 2 wt.% was prepared by deposition-precipitation using iridium chloride (IrCl(3)) as a precursor at 75 degrees C and pH = 9 (adjusted with 0.25 M Na(2)CO(3)). Catalytic activities toward the steam reforming of ethanol (SRE) were tested in a fixed-bed reactor. In order to better understand the effect of activation conditions of a catalyst on the reforming of ethanol, reduction pretreatment at 200 and 400 degrees C (assigned as H(2) and H(4)) were conducted. The results indicated that only less sintering influences the catalytic activities for high temperature reduction. The ethanol conversion approached completion around 450 degrees C via reduction pretreatment for In CeO(2)(U) and Ir/CeO(2)(C) samples under H(2)O/EtOH molar ratio of 13 and 22,000 h(-1) GHSV. Not only was a high dispersion of both catalysts present but also no impurities (e.g., boron) interfered with the catalytic activities. The hydrogen yield (H(2) mole/EtOH mole) exceeds 5.0 with less content of CO and CH(4) (<2%). (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.