Sonochemical Synthesis of Nanostructured Molybdenum Sulfide

Abstract

There is growing interest in nanostructured inorganic materials, in large part because they often exhibit properties distinct from those of the bulk that can prove useful in various applications, including heterogeneous catalysis.1-4 The established methods for the preparation of nanostructured inorganic materials include metal evaporation,5 reduction of metal salts,6,7 and thermal decomposition and laser pyrolysis of organometallic compounds.8,9 In addition, the sonochemical reaction of volatile organometallics is a recent and general synthetic approach to nanophase transition metal powders, alloys, carbides, and colloids.10-13 We report here a simple sonochemical synthesis of nanophase, high-surface-area molybdenum sulfide and the examination of its catalytic activity for thiophene hydrodesulfurization (HDS). MoS2 was prepared by irradiating a slurry of molybdenum hexacarbonyl and sulfur in 1,2,3,5-tetramethylbenzene (isodurene) with high-intensity ultrasound (20 kHz) under Ar.14a Elemental analysis of the purified powder indicates a stoichiometric molybdenum sulfide (S/Mo atomic ratio of 2.0) with a trace amount (<2 wt %) of carbon contamination. For comparison, a conventional molybdenum sulfide sample was also prepared by