Dresden 2017 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 107: Heterogeneous Catalysis: Theory II
O 107.9: Vortrag
Freitag, 24. März 2017, 12:30–12:45, TRE Phy
On the effect of electromagnetic field heterogeneities on the chemical kinetics on nano-structured photocatalysts — •Sebastian Matera1, Martin Hammersachmidt2, Sandra Döpking1, Sven Burger2, and Frank Schmidt2 — 1FU Berlin, Germany — 2Zuse Institute Berlin, Germany
When going from single crystal surfaces to structured catalysts, such as powders or nano-particles, the complexity of the problem dramatically increases. Besides the obvious higher structural complexity, the electromagnetic field, driving photocatalysis, might become heterogeneous on a nanoscale level. We present a simple model for the CO2 reduction on titania anatase, which addresses the impact of these heterogeneities on the photocatalytic kinetics by coupling kinetic Monte Carlo with electromagnetic wave simulations. Our results indicate that catalytic activity might vary significantly on a single facet of a nanocrystal. Moreover, the coverage situation might change laterally on this facet and we have a concomitant change of the rate-determining steps. This heterogeneity on all levels of photocatalytic activity makes it extremely difficult to draw mechanistic conclusions from experimental studies on such structured catalysts, where only the spatially averaged activity can be addressed.