Reactive nanocomposites based on pillared clays

Abstract

This work concerns the preparation of novel nanocomposite materials deriving from pillared clays, which have been functionalised by treatment with either vanadium pentoxide or p-toluenesulfonic acid, with the aim to obtain porous materials with oxidant or strong acid character, respectively. The synthesis involves the use of montmorillonites and saponites, as starting 2:1 charged phyllosilicates to give the alumina pillared clays employed as host matrices for reagent inclusion. Characterisation of the resulting materials was provided by chemical and thermal analyses, XRD, SEM-EDX, FTIR and XPS spectroscopies, specific surface area and porosity measurements, and electrochemical impedance technique. The reactivities of the nanocomposite materials have been tested with positive results in the oxidation of alcohols to carbonyl compounds, in particular in the oxidation of benzyl alcohol to benzaldehyde, and also in the syntheses of methyl tert-butyl ether (MTBE) and bisphenol A. Good correlation between the proton conductivity obtained from electrochemical impedance and the acid catalytic activity of nanocomposites containing p-toluenesulfonic acid has been found.