Isomerization of n-hexane in the presence of Pt-containing sulfated zirconia catalysts supported on alumina

The effect of phase composition and textural characteristics of alumina on physicochemical and catalytic properties of supported sulfated zirconia catalysts in isomerization of n-hexane was studied. The catalysts were examined using atomic emission spectroscopy, nitrogen adsorption-desorption, XRD, TPD of ammonia, and IR spectroscopy of adsorbed pyridine. Samples were tested in the reaction of n-hexane isomerization. It was shown that the use of α-Al2O3 as the support leads to the formation of a mixture of monoclinic and tetragonal zirconia phases and decreases the catalytic activity. The use of γ and θ alumina species as the supports stabilizes the tetragonal zirconia phase, which is active toward isomerization of n-hexane. Investigation of acid sites revealed that the increased contribution of Lewis acid sites in supported sulfated zirconia catalysts enhances the catalytic activity and increases the yield of hexane isomers.