In this work, CeO2-ZrO2-Al2O3 (CZA) composites promoted by selective doping with Ba were prepared by simple coprecipitation method. The structural characterization results reveal that with small doping amount (<= 6 wt%), Ba can preferentially combine with Al2O3 and acts as a stabilizer, which could facilitate the formation of more homogeneous CZ solid solutions. When the content of BaO increases to 8 wt%, besides the portion combined with Al2O3, the remnant Ba would enter into the lattice of CeO2-ZrO2 to form a ternary CeO2-ZrO2 BaO solid solution, thus further improved oxygen mobility is obtained. However, excessive doping amount (10 wt%) brings about self-aggregation of BaO, which seriously deteriorates the structure of the CeO2-ZrO2-Al2O3-BaO composite. The XPS results demonstrate that with optimal doping content of BaO (8 wt%), the supported catalyst Pd/CZAB8 possesses highest surface Pd and Ce3+ concentrations, which consequently leads to improved reducibility and catalytic performance. Furthermore, the synergistic effect between CeO2-ZrO2-BaO and BaO Al2O3 helps improve the thermal stability of Pd/CZAB8. Thus, superior textural, structural, morphological and reduction properties along with enhanced three-way catalytic performance are obtained for aged Pd/CZAB8a. (C) 2015 Elsevier B.V. All rights reserved.