Synthesis, characterization and applications of highly active and robust sulfated Fe–TiO₂ catalyst (ICT-3) with superior redox and acidic properties

Abstract

A novel multifunctional sulfated Fe–TiO₂ catalyst with different Fe loading, leading to the introduction of both redox and superacidic properties (designated as ICaT-3), was developed. Chorosulfonic acid was used to create super acidity in the catalyst matrix. The catalyst was characterized by FT-IR, XRD, TG-DTA, surface area measurements, NH₃-TPD, XPS, SEM and EDX analysis with reference to its superior redox and acidic properties. The catalyst was found to be very active and selective as compared to unsulfated catalyst for industrially important oxidation reaction of benzyl alcohol to benzaldehyde and its efficacy was tested in a variety of substrates such as 4-methoxy benzyl alcohol, 4-chlorobenzyl alcohol, styrene, p-bromostyrene, and methyl phenyl sulfide. This induced acidity increases the oxidation activity by twofold as compared to conventional TiO₂ catalyst. Its superior acidic properties were also evaluated in the alkylation of toluene with benzyl alcohol. The catalyst was reused repeatedly to find it as stable and reusable.