This study investigated the effect of adding CeO2 to an Rh/Al2O3 catalyst on the decomposition of nitrous oxide (N2O). The Rh/CeO2 catalyst was shown to have a high catalytic activity but was significantly affected by oxygen. In contrast, the Rh/Al2O3 catalyst has moderate catalytic activity and was unaffected by oxygen. In order to avoid the adverse effects of oxygen while simultaneously enhancing catalytic activity, we developed a new catalyst, Rh/CeO2-Al2O3, which was prepared using three different methods (impregnation, co-precipitation, and ball milling). Activity tests, H-2 TPR, DRIFTS, and O-2 off/on tests confirmed that the Rh/CeO2-Al2O3 catalyst prepared using the co-precipitation method had the highest catalytic activity and inhibition by oxygen was reduced. (C) 2011 Elsevier B.V. All rights reserved.