A non-porous supported-platinum catalyst for aromatization of n-hexane

Abstract

THE cyclization of C₆ and C₇n-alkanes to form aromatic compounds is highly desirable in the petroleum-refining industry. Platinum metal clusters incorporated into the channels of zeolite L have been found to catalyse the aromatization of hexane and heptane with high activity and selectivity^1,2. The susceptibility of this catalyst to sulphur poisoning, however, means that the hydrocarbon reagents must be of high purity, free from sulphur contamination². It has been generally believed that the pore structure of the zeolite plays an important part in the selectivity of the catalytic process. Here we describe a non-porous platinum catalyst that can convertn-hexane to benzene with an activity and selectivity comparable to that of the zeolite. The catalyst consists of platinum clusters, about 2 nm in diameter, supported on a basic, high-surface-area magnesium oxide stabilized by aluminium. The product distribution for n-hexane is almost identical to that obtained using the zeolite L catalyst. These results point to a new approach to hydrocarbon reforming based on metal species supported on highly basic, non-porous carriers.