Iron phthalocyanine supported on silica or encapsulated inside zeolite Y as solid photocatalysts for the degradation of phenols and sulfur heterocycles

The photocatalytic activity of iron phthalocyanine adsorbed on silica (FePc/SiO₂) or encapsulated within NaY zeolite (FePc@NaY) towards the degradation of two model compounds using hydrogen peroxide as oxidant has been determined. It was found that while FePc/SiO₂ exhibits higher intrinsic activity than FePc@NaY for the degradation of phenol in water, FePc/SiO₂ cannot be used as heterogeneous photocatalyst in organic solvents due to self-degradation and/or desorption of the iron phthalocyanine from the silica surface to the solution. Thus, for the oxidative photodegradation of benzothiophene in acetonitrile using FePc/SiO₂ as photocatalyst (a model reaction with importance in the fuel industry), the silica becomes colorless and without possibility of reuse. In contrast, FePc@NaY, in where iron phthalocyanine is permanently immobilized inside the zeolite pores, can be recovered by filtration after the photodegradation of benzothiophene in acetonitrile and reused.