Role of Constituent Oxides for Thermal Mineralization of o‐Dichloro Benzene over Mixed‐Oxide‐TiO₂ Catalysts: A Mechanistic Explanation

Catalysts with V 2 O 5 , WO 3 and V 2 O 5 −WO 3 dispersed over TiO 2 were synthesized using sol‐gel technique and thoroughly characterized by various techniques. The catalysts were evaluated for degradation of ortho‐dichloro benzene ( o‐DCB ) in air/helium, a representative probe molecule for polychlorinated dibenzo‐para‐dioxin and polychlorinated dibenzofuran by employing in situ Fourier‐transform infrared spectroscopy (FT‐IR spectroscopy). Different intermediate species formed on the surface of the TiO 2 supported catalysts through of interaction of sorbate molecules with the lattice and/or gaseous oxygen were investigated in detail. Analysis of vibrational bands, observed during sorption of o‐DCB and o‐DCB ‐air mixture as a function of temperature over these catalysts, delineated the role of surface intermediate species such as phenolate, enolates, maleates, carboxylates, carbonates in mineralization of o‐DCB . Nature and stability of intermediate species, found to be different over these catalysts, were able to elucidate the catalytic activity trend.