The present work investigates the catalytic performances of 20 wt.% Ba supported CexZr1-xO2 (x = 0, 0.3, 0.5, 0.7, 1) NOx storage catalysts, where 2 wt.% Pt/Al2O3 part was blended in as physical mixtures. The interests were focused on the effects of Ce-Zr compositions as support oxides to barium species in NOx storage and release cycles. Higher Ce content favors rapid NOx up-taking and stable adsorption in adequate amount of small BaCO3 particles. The increasing amount of Zr in CexZr1-xO2 may benefit the formation of porous texture, but it brings the higher risk of BaZrO3 formation during the ageing. It not only consumes active Ba sites for NOx storage, but induces even severe sintering to these materials. Additionally, the introduced ZrO2 may increase oxygen mobility to improve redox activities of the catalysts. This improvement could lower the NH3 release in rich period. However, to another extreme, a too strong oxidative activity is going to inhibit the NOx reduction due to its stabilization to intermediate NO2 delta+ species. (c) 2010 Elsevier B.V. All rights reserved.