Preparation and characterization of a new iron-tungsten phosphate Catalytic activity in the oxidation of cyclohexane to cyclohexanol

Abstract

In the last few years, the metallophosphate chemistry was extensively investigated in order to obtain materials with a wide range of applications. Among them, those with transition metals aroused the strongest interest due to their potential applications in non- linear optic, ion exchange, ion conductivity and catalysis.

We report herein the synthesis of a bimetallic iron-tungsten phosphate that was obtained hydrothermally, by using N,N‟-dimethyl piperazine as the structure directing agent.

The solid material was characterized by several physico-chemical techniques such as: X- ray diffraction, chemical and thermal analyses, scanning electron microscopy, N2 adsorption isotherms and FTIR and Mössbauer spectroscopies.

In the aim of evaluating the performance of this product as heterogeneous catalyst, we tested it in a probe reaction for the oxidation of cyclohexane, with hydrogen peroxide as oxidant.

The reaction was carried out at 70°C for 6h, using cyclohexanol and methyl ethyl ketone as initiators. The results of the study showed that the material exhibited a high catalytic activity. Moreover, it was observed a more marked activity when the reaction was carried out with cyclohexanol as initiator, when compared to methyl ethyl ketone