Two nanocomposites of different layer thickness were synthesized by impregnation of a rutile titania support with a reduced ceria solution. An in situ spectroscopic DRIFTS-MS study has shown remarkable differences in the interaction of these nanocomposites with ethanol depending on the layer thickness and the environment (oxidizing/reducing). Under anaerobic conditions it was found that the surface-support interaction allowed to stabilize the ceria in the reduced form (Ce 3+ ) until temperatures as high as 300°C, especially for the thinner layer. The intrinsic characteristics of these materials were proven useful in the dehydrogenation of ethanol to acetaldehyde since they inhibited further oxidation products (typical in the case of bulk ceria) and dehydration products (such as ethylene, the main product for bulk titania), and even promoted aldolic condensation to crotonaldehyde. All this, without the need of using expensive noble metals as catalysts or hydrogen to keep the ceria reduced.