In situ FTIR spectroscopy was used to study the interaction of pyridine-3carbaldehyde (3PyA) with the surface of TiO2 and a V-Ti-O catalyst in the temperature range of 120-300degreesC. 3PyA interacts with Lewis and Bronsted acid sites of TiO2 and the V-Ti-O catalyst to form a nitrogen-coordinated complex and a a-bonded (through oxygen of the CHO group) complex, as well as a complex protonated at the N atom in the ring. Surface carboxylates (nicotinates) were also identified during the interaction of 3PyA with the V-Ti-O catalyst in the temperature range of 200-300degreesC.