Preparation and property investigation of CeO2-ZrO2-Al2O3 oxygen-storage compounds

Oxygen-storage materials CeO2-ZrO2-Al2O3 (CZA), with alumina contents 10, 25, 50, 75 and 90wt%, respectively, were prepared by the co-precipitation method. To compare our results with those of CeO2-ZrO2 (CZ), the prepared materials were characterized by Brunauer-Emmet Teller method (BET), X-ray diffraction (XRD), Raman spectrum, temperature-programmed reduction (H-2-TPR) and oxygen pulsing technique (OSC). The XRD and Raman results show that all samples (except sample with 90 wt% alumina) can keep the single CeO2 cubic fluorite structure after calcination at 873 and 1273 K for 5 h, respectively. Compared with the fresh samples, the particle sizes of aged samples increase, but no phase separation occurs. According to the results of BET and OSC, after calcination at 1273 K, alumina doped can make this system materials maintain higher specific surface area (114.5 m(2) g (- 1)) and larger pore volume (0.36 ml g (- 1)) without losing characteristics of CeO2. As Al2O3 contents increase, the ratio of utilizable cerium also increases, indicating that the OSC of CZA is more stable than that of CZ. In this work, the prepared CZA materials are highly dispersed composite solid solutions. After calcination at 1273 K, those compounds can still keep the structural and textural stability, and simultaneously hold excellent OSC and stable redox property. (c) 2007 Elsevier B.V. All rights reserved.