Characterization of V2O5-TiO2 Eurocat Catalysts by Vibrational and Electronic Spectroscopies

IR and Raman spectroscopic studies show that the catalyst EL10V1 consists of a 'monolayer' of surface vanadyl complexes spread on the TiO₂ support surface. Such a 'monolayer' contains both Lewis and Brensted acidic sites, while the nucleophilic sites of the support surface are suppressed. On the catalyst EL10V8, V₂O₅ particles are also present. UV-Vis spectra show that V⁵⁺ is predominant on the calcined catalysts; part of it can be converted easily into V⁴⁺. Evidence is also found for electronic interaction between the support and the surface vanadium oxide species.