Bifunctional catalysts from pillared clays: Vapour phase conversion of propene to acetone catalyzed by iron and ruthenium containing aluminum pillared bentonites.

A natural bentonite was pillared with aluminum, aluminum—iron and aluminum—ruthenium polyoxocations. The alkali cations of some clays were successively exchanged with iron. The prepared pillared clays were characterized by X-ray diffraction, DTA, TGA, ESCA and N₂ adsorption. The relative amount of Lewis and Brønsted acid sites was estimated from FT-IR spectra of adsorbed pyridine. All the clays resulted active catalysts for the vapour phase conversion of propene to acetone in the 150–350°C temperature range. The reaction appeared to occur via acid catalyzed propene hydration to isopropanol and successive oxidative dehydrogenation of the alcohol to acetone. The reactivity of all the prepared samples was correlated to the nature and number of the redox and acid sites.