In this study the effect of ceria addition on the performance of a model Ba-based lean NOx trap (LNT) catalyst was examined. The presence of ceria improved NOx storage capacity in the temperature range 200-400 degrees C under both continuous lean and lean-rich cycling conditions. Temperature-programmed experiments showed that NOx stored in the ceria-containing catalyst was thermally less stable and more reactive to reduction with both H-2 and CO as reductants, albeit at the expense of additional reductant consumed by reduction of the ceria. These findings demonstrate that the incorporation of ceria in LNTs not only improves NOx storage efficiency but also positively impacts LNT regeneration behavior.