A study using TEM combined with electron diffraction (ED), several spectroscopies (IR, ESR, XPS), and mass spectrometry-temperature programmed surface reaction of adsorbed NO is carried out on a Cu/CeOx/Al2O3 catalyst and on similar specimens without Ce or Cu. TEM shows a preferential nucleation of the oxidized Cu phase on the ceria-rich regions, leading to a particle size in the Cu-containing phase smaller than that found in the Al2O3-supported system and decreasing the formation of the CuAl2O4 spinel. The Cu-Ce interaction developed in the calcination treatment also gives significant stability against sintering of the metallic copper phase formed during H-2 reduction. After reduction, the Ce-containing sample shows higher resistance to reoxidation of the surface copper phase by NO to the Cu2+ State (in comparison to Cu/Al2O3), On the basis of XPS-Ar+ sputtering data, this may be related to partial coverage of the metallic Cu by reduced ceria in a way similar to that currently accepted for the SMSI effect; a capability of the Ce-containing support to stabilize the Cu+ state may also contribute to this behaviour. This stable copper state appears in subsurface regions and is likely related to a new phase detected by TEM-ED and tentatively identified as a (Ce,Cu)-Al perovskite, The copper-cerium interaction affects also the reactivity of the catalyst towards NO, increasing (partly through a dissociative mechanism) the amount of adsorbed species which leads to low temperature NO and N-2/N2O desorption, as well as shifting the decomposition temperatures of surface species containing N-N bonds (N-2/N2O) formed upon NO adsorption. It is proposed that the addition of ceria may help to enhance the reductive elimination of NO by copper in automobile exhaust gases.