Abstract Triton X-100 was oxidized in aqueous solutions with the presence of O 2 using photocatalysis and H 2O 2 addition alone or coupled. New supported TiO 2/Al 2O 3 catalysts modified with vanadium and cobalt were used. Catalysts were prepared using the classical impregnation method (CIM) and the double impregnation method (DIM). The effect of the physico-chemical properties of the catalysts on its activity were studied. The research on the interactions between the metal precursor and the titania–alumina surface by means of FT-IR/PAS (Fourier transform infrared photoacoustic spectroscopy) were also conducted.