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CPM Seminar
Henrik Mortensen
Physics Department The field of gas-surface dynamics aims at obtaining a detailed physical understanding of how otherwise gas-phase chemical reactions are affected by the presence of a solid surface. From the point of view of applications, it would be desirable to be able to optimize the catalysts essential to chemical industry, without relying on `gut feeling' and blind trial-and-error approaches. Linking ab initio theory to real-life catalysis is generally a formidable task, though, so meanwhile theory is being tested in `model system' experiments which provide increasingly detailed information about the reactions. During the last few years, the gas-surface reaction dynamics group at the University of Southern Denmark has applied and developed laser and molecular beam methods to extract details of the activated dissociative adsorption of several `simple' molecules on the Ru(0001) surface. I will present briefly some of the experimental techniques, notably that of laser assisted associative desorption (LAAD). The dissociation mechanisms of N2 and CH4 have been heavily debated in the past. Our recent experimental results bring us one step closer to a detailed description of these mechanisms. In addition, the large differences between the two reactions lead us to conclude that the interpretation of data obtained by `well-known' techniques may have to be revised when the techniques are applied to very different systems.
Thursday, November 14th 2002, 15:30 |