Hydrogen production from steam reforming of ethanol using a ceria-supported iridium catalyst: Effect of different ceria supports

Catalytic activity of a ceria-supported Iridium (Ir/CeO2) catalyst was investigated for steam reforming of ethanol within a temperature range of 300–500 °C. Three types of ceria were chosen to prepare the catalyst: commercial [assigned as CeO2(C)] and prepared [using a simple reduction–oxidation method, CeO2(R), and another combined with ultrasonic irradiation, CeO2(U)] ceria. The Ir/CeO2 catalyst with Ir loading of 2 wt.% was prepared by deposition–precipitation using iridium chloride (IrCl3) as a precursor at 75 °C and pH = 9 (adjusted with 0.25 M Na2CO3). 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 °C (assigned as H2 and H4) were conducted. The results indicated that only less sintering influences the catalytic activities for high temperature reduction. The ethanol conversion approached completion around 450 °C via reduction pretreatment for Ir/CeO2(U) and Ir/CeO2(C) samples under H2O/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 (H2 mole/EtOH mole) exceeds 5.0 with less content of CO and CH4 (<2%).