Physico-chemical characteristics of sulfated mixed oxides of Sn with some rare earth elements

A series of binary mixed oxides of tin with three rare earth elements viz. La, Ce and Sm were prepared by co-precipitation method and sulfate treatmen t was performed by treating the mixed hydroxides with sulfuric acid or ammo nium sulfate. The physicochemical characterization has been done by XRD, BE T-SA, SEM, EDX, TG-DTA and IR spectroscopy. Adsorption of n-butylamine was used to probe the acidic properties of the catalysts. The strength and dist ribution of acid sites depend on the mixed metal oxide composition, as well as on the preparation method. The rare earth modified sulfated tin oxide c atalysts are more active in the oxidative dehydrogenation of cyclohexanol a nd cyclohexane, compared to the corresponding mixed oxide systems and sulfa ted tin oxide. Among the different sulfated oxide systems investigated, cer ium promoted catalysts displayed a better selectivity towards dehydrogenati on products.