Dresden 2020 – wissenschaftliches Programm
Die DPG-Frühjahrstagung in Dresden musste abgesagt werden! Lesen Sie mehr ...
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 16: Nanoscale Heterogeneous Catalysis
O 16.3: Hauptvortrag
Montag, 16. März 2020, 15:30–16:00, TRE Ma
Nanotuning via local work function control: Ethylene hydrogenation on supported Pt nanoclusters — •Ueli Heiz1, Marian D. Rötzer1, Maximilian Krause1, Andrew S. Crampton1, Bokwon Yoon2, and Uzi Landman2 — 1Lehrstuhl für Physikalische Chemie, Catalysis Research Center & Chemistry Department, Technische Universität München, Lichtenbergstraße 4, 85748 Garching, Germany — 2School of Physics, Georgia Institute of Technology, Atlanta, GA 30332-0430, USA
Prevention of blocking and deactivation of the hydrogenation of unsaturated hydrocarbons resulting from carbonaceous coke formation is a major challenge. Here we demonstrate experimentally and theoretically that the activity, selectivity, specificity and deactivation of size-selected platinum clusters can be controllably tuned by manipulating the local electronic density of the catalyzing Pt cluster via appropriate choice of the support system. We show that along with interfacial particle-to-support bonding effects, electron transfer and charge balance on the supported sub-nanometer metal clusters, controlling the catalysts activity, can be tuned by the local work function of the catalysts support. Control of this materials property was demonstrated through synthesis of ultra-thin amorphous silica, a-SiO2, films on single crystals with differing work-functions, Pt(111) or Mo(211), serving as supports for the active sub-nanometer cluster component. The new catalytic control factor introduced here, akin to support-doping, allows steering of the chemical catalytic activity and may be used to inhibit undesirable catalyst poisoning and coke formation.