Properties of sonochemically synthesized, highly dispersed MoS2/Al2O3 catalysts for the hydrodesulfurization of dibenzothiophene and 4,6-dimethyldibenzothiophene

The sonochemical decomposition of molybdenum hexacarbonyl in the presence of sulfur and alumina generated a highly dispersed MoS 2 /Al 2 O 3 catalyst. The catalysts were tested for the hydrodesulfurization (HDS) of dibenzothiophene and 4,6-dimethyldibenzothiophene. This sonochemically synthesized catalyst prepared by the direct sonication of molybdenum hexacarbonyl and sulfur exhibited superior HDS and hydrogenation activity compared to that of the catalysts prepared by other methods. The nitric oxide chemisorption studies of the catalysts revealed that the enhanced HDS activity resulted from the improved dispersion of the active species on the support. Temperature programmed reduction indicated that the poisoning of catalytically active sites by hydrogen sulfide did not occur on the sonochemically prepared catalysts. On the other hand, the catalysts prepared by the calcination and sulfidation of sonochemically generated Mo 2 C/Al 2 O 3 showed low HDS activity due to the agglomeration of the surface particles during the heat treatments.