Hydrothermal stability of CeO2-Al2O3 composites, a structural study and oxygen storage capacitiesElectronic supplementary information (ESI) available: Details of the calculation of oxygen storage capacity. See DOI: 10.1039/c5ra15731e

A series of CeO 2 -Al 2 O 3 composites with different Ce content were prepared. The uniformity of the CeO 2 dispersion was confirmed using H 2 -TPR and HR-TEM. Two aging treatments were conducted, and the CeO 2 -Al 2 O 3 composites show superior hydrothermal stability. The sintering of CeO 2 and Al 2 O 3 are independent of each other based on XRD and HR-TEM results. On the other hand, the dynamic oxygen storage capacity (DOSC) is mostly activated after 20 h of aging at 750 °C, and deactivated after 10 h of aging at 1050 °C. Combining the results of structural and DOSC studies, the interaction between CeO 2 and Al 2 O 3 can be divided into two parts, (1) a chemical interaction which negatively impacts the DOSC, and (2) a spatial limitation which benefits the sample stability. The former interaction is eliminated after hydrothermal aging at 750 °C, while the later one exists even after hydrothermal aging at 1050 °C. A series of CeO 2 -Al 2 O 3 composites with different Ce content were prepared.