Paper SS2+NC-ThM11
Size-Selected Deposition of Transition Metal Sulfides

Thursday, October 23, 2008, 11:20 am, Room 208

Supported MoS₂ nanoparticles are known for their ability to catalyze a wide array of heterogenous reactions and work done in our laboratory is geared towards understanding the role of size, structure, composition and support interactions of the particles in these reactions. This problem has not yet been resolved due to the inhomogeneity of commercial catalysts. We therefore focus on preparing homogenous samples in ultra high vacuum that can serve as model systems for catalytic reactions such as hydrodesulfurization. A recently constructed cluster beam apparatus in our laboratory uses magnetron sputtering in order to make a variety of transition metal cluster compounds. We are currently investigating the size dependent and substrate dependent properties of these systems in particular Mo_xS_y⁺ clusters (x=2-8, y= 6-12) on single crystal surfaces (i.e. Au(111), Al₂O₃/NiAl(110)). Characterization of the clusters are carried out using surface sensitive techniques such as Auger, photoemission spectroscopy, and thermal desorption. Preliminary work on the reactivity of these clusters with small sulfur containing molecules will also be discussed.