Berlin 2008 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 28: Symposium: Size-Selected Clusters at Surfaces II
(Invited Speakers: Steven Buratto, Stefan Vajda, Matthias Arenz)

O 28.2: Hauptvortrag (ohne Erstattung)

Dienstag, 26. Februar 2008, 11:45–12:15, MA 005

Towards the understanding of size/shape and function relationship in catalysis of complex reactions — •Stefan Vajda¹, Sungsik Lee¹, Larry A. Curtiss¹, Jeffrey P. Greeley¹, Paul C. Redfern¹, Peter Zapol¹, Michael J. Pellin¹, Jeffrey W. Elam¹, Byeongdu Lee¹, Sönke Seifert¹, Randall E. Winans¹, Yu Lei^1,2, Randall J. Meyer², Arantxa Fraile-Rodríguez³, Luis M. Molina⁴, Maria J. López⁴, Julio M. Alonso⁴, Kristian Sell⁵, Ingo Barke⁵, Armin Kleibert⁵, Viola von Oeynhausen⁵, and Karl-Heinz Meiwes-Broer⁵ — ¹Argonne National Laboratory, Argonne, USA — ²University of Illinois at Chicago, USA — ³Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland — ⁴Universidad de Valladolid, Valladolid, Spain — ⁵Institut für Physik, Universität Rostock, Rostock, Germany

This contribution focuses on partial oxidation reactions catalyzed by sub-nanometer to several ten nanometer large size-selected clusters. Catalytic performance and changes in cluster shape are studied under realistic reaction conditions, allowing to elucidate the size/shape/composition and function relationship in catalysis. Here we show 1) gold and silver clusters which promote with high selectivity the direct oxidation of propylene to propylene oxide, and 2) sub-nanometer platinum clusters catalyzing the oxidative dehydrogenation of propane with high selectivity and activity. Theoretical calculations and modeling provide a detailed insight of the catalytic process. The findings stress the important role of small clusters in promoting reactions with high selectivity and activity.