Dresden 2009 – wissenschaftliches Programm

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SYCR: Symposium Chemical Reactions on Nanomaterials: Progress from in-situ Experimental Studies and Theoretical Investigations

SYCR 1: Chemical Reactions on Nanomaterials

SYCR 1.6: Hauptvortrag

Donnerstag, 26. März 2009, 17:00–17:30, BAR SCHÖ

Computational materials design: Alloys for selective hydrogenation catalysis — •Thomas Bligaard — Center for Atomic-scale Materials Design, Dept. of Physics, Build. 307, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark

Scaling relations are presented which have the capability to estimate adsorbate-surface bond energies for hydrogen-containing molecules on transition metal surfaces with reasonable accuracy. The relations provide a method for estimating hydrogenation reaction energies, leading to new possibilities in using electronic structure simulations in the seach for new catalysts. Using the selective hydrogenation of acetylene to ethylene as an example, it is shown how the adsorption energy of one single species can be used as a descriptor for the catalytic activity and selectivity. A number of alloys are investigated and new catalysts are singled out and experimentally tested, leading to the suggestion of new potential catalysts not containing precious metals. That scaling relations hold for adsorption energies of molecules larger than one carbon atom, suggests they can provide a method for treating the surface chemistry of more complex hydrocarbons. It is finally shown that the scaling model surprisingly can be generalized to the surfaces of more complex materials such as oxides and nitrides.