Abstract

In this paper, high surface area nanocrystalline gamma alumina was synthesized by the sol-gel method using cationic surfactant. The Pt-based dehydrogenation catalysts consisting of promoters and support modifiers (Sn, In, Li and Fe) were prepared using the synthesized gamma alumina and employed in the dehydrogenation reaction of n-dodecane. The effects of different successive impregnation methods for Pt, Sn and In elements were investigated in dehydrogenation of normal dodecane. The prepared samples were characterized by X-ray diffraction (XRD), N₂ adsorption (BET), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Temperature programmed reduction (TPR) techniques. The catalytic performances of the prepared samples showed the best catalytic results for the catalyst which was prepared by the co-impregnation of In, Sn and Fe in the first step followed by Pt and Li impregnation in the second and third step, respectively. The synthesized support also performed well as an efficient carrier for the dehydrogenation catalyst of higher normal paraffins.

Key words: Nanomaterials, sol–gel preparation, γ-Al₂O₃, dehydrogenation catalyst, catalyst modifiers, successive impregnation.