Pt catalysts supported on Al-HMS materials having different Si/Al ratio were prepared and characterized by XRF, N2 adsorption–desorption isotherms, NH3-TPD and pyridine-adsorbed FTIR techniques. The catalytic performance of samples was investigated for the hydroisomerizaton of n-heptane in the temperature range of 250–400 °C and compared as a function of Al content. The catalytic evaluation revealed that Pt/Al-HMS catalysts had a high activity and unique selectivity to multibranched (MuB) isoheptanes. The molar ratio of MuB to monobranched isoheptanes (R) in the isomerization products varies within a very narrow range between 0.7 and 1.1, which is several times greater than those reported in the literature under similar reaction conditions using zeolite-supported catalysts. The formation of the MuB isoheptanes had a close correlation with the mesopore diameters of the catalysts.
1. Zakumbaeva, GD, Van, TV, Lyashenko, AI, Egizbaeva, RI2001Catal Today65:191.