Structural (XRD) and spectroscopic (EPR, IR and Raman) investigations were per-formed to elucidate the influence of CeO2 content on the phase composition and surface chemistry of CexZr1-xO2 solid solutions (x = 0.10-0.85), interacting with NO and NO2 in the absence and presence of oxygen. Strong influence of ceria loading on the adsorption modes of both nitrogen oxides and the nature of the resultant surface species was revealed. Adsorption of NO led to formation of mononitrosyl complexes, dimers and N2O, whereas interaction of NO2 with the ceria-zirconia catalyst resulted in the adsorbate disproportionation or coupling, depending on the sample composition. (c) 2006 Elsevier B.V. All rights reserved.