(97h) Laser Deposition Method for the Synthesis and Analysis of Nanostructured Catalysts

Discovery and characterization of new catalytic materials is important for further industrial growth. Using laser ablation, we have developed a novel method to deposit metal atoms directly on an inert substrate. High energy laser light pulsed at a metal disc under vacuum creates a shower of metal atoms and clusters. These settle on a vibrating bed of inert particles. The random vibrations ensure that the metal atoms will be spread over the surface of the substrate. By varying the time that the inert particles are exposed to the atom shower, we control the amount of metal atoms deposited.

Our current studies involve systems of palladium metal deposited on quartz particles. We use the relatively simple oxidation reaction of carbon monoxide to carbon dioxide to study the kinetic characteristics of the catalyst. Our Temporal Analysis of Products (TAP) technique allows us to study a small sample of catalyst in unsteady state conditions. The data indicates that oxygen uptake by the surface is directly related to the amount of palladium deposited. Carbon dioxide production is dependent on both temperature and catalyst surface coverage by oxygen. We also note that there is a distinction between bulk and surface oxygen.