Study of the catalytic activity of Al-Fe pillared clays in the Baeyer-Villiger oxidation

Three types of AlFePILCs pillared clays have been prepared from Algerian clay precursors. They have been characterized and tested in the Baeyer-Villiger oxidation of cyclohexanone to caprolactone using benzaldehyde and oxygen as oxidant at room temperature. The structural and textural properties of the catalyst have been determined by X-ray diffraction, nitrogen adsorption-desorption isotherms and Mossbauer spectroscopy. The different activities of the clays have been related to their Fe contents and accessible surface areas. The induction period observed before the reaction started has been attributed to the dissolution of a portion of the Fe3+ cations, mediated by either the perbenzoic acid intermediate or the benzoic acid co-product. The reaction was indeed catalysed by a few ppm of dissolved iron cations and the catalysis of the Baeyer-Villiger oxidation reaction should mechanistically be considered as homogeneous.