Preparation of gadolinia doped ceria via metal complex decomposition method: Its application as catalyst for the steam reforming of ethane

The ceria (CeO2) and gadolinia doped ceria (GDC; Ce1-xGdxO2-delta with x = 0.10, 0.15, and 0.20) catalysts were successfully prepared via metal complex decomposition method at 900 degrees C for 2 h. The synthesized CeO2 and GDC were found to have useful activity to convert ethane to syngas via the steam reforming reaction at the temperature range of 800-900 degrees C. The catalytic activity was improved with increasing Gd doping amount from 0 to 0.1 and 0.15; nevertheless, at higher Gd doping content (0.2), the improvement becomes less pronounced. Among all catalysts, Ce0.85Gd0.15O2-delta showed the best steam reforming activity; furthermore, the amount of carbon formation over this catalyst was relatively low. These enhancements are mainly due to the high specific surface area and the good oxygen storage capacity (OSC) of the material. During the steam reforming process, the gas-solid reactions between the gaseous components presented in the system (C2H6, C2H4, and CH4) and the lattice oxygen (O-x) on the surface CeO2 or GDC occurs. The reactions of hydrocarbons adsorbed on the surface with O-x (CnHm + O-x -> nCO + m/2(H-2) + Ox-n) can prevent the formation of carbon species from hydrocarbons decomposition reaction (CnHm double left right arrow nC + m/2H(2)). Moreover, the formation of carbon via Boudouard reaction (2CO double left right arrow CO2 + C) is also reduced by the gas-solid reaction of CO with the lattice oxygen (CO + O-x double left right arrow CO2 + Ox-1). (C) 2012 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.