Regensburg 2016 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 9: Nanoparticles, Nanocrystals and Composites II

CPP 9.5: Vortrag

Montag, 7. März 2016, 16:00–16:15, H41

Characterization of active iron cites in Fe-ZSM-5 catalysts using Mössbauer spectroscopy — •Kydala Ganesha Padmalekha¹, Heming Huang¹, Inga Ellmers², Roxana Pérez Vélez³, Angelika Brückner³, Wolfgang Grünert², and Volker Schünemann¹ — ¹Department of Physics, University of Kaiserslautern, 67663 Kaiserslautern, Germany — ²Lehrstuhl Technische Chemie, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany — ³Leibniz-Institut für Katalyse e. V., 18059 Rostock, Germany

Fe-ZSM-5 catalysts are important in catalytic reduction of NOx by NH3 in vehicle exhausts. The iron centres in the hetergogeneous catalyst can exist in various forms and oxidation states after iron loading and pretreatment and it is non trivial to identify and quantify them. We have investigated isotopically enriched 57Fe-ZSM-5 (Si/Al ~ 14, <= 0.7 wt% Fe), which was prepared via solid-state ion exchange, before and after standard selective catalytic reduction SCR (sSCR) using field dependent Mössbauer spectroscopy. We present deconvolution of the spectra into contributions from the different iron species and their corresponding abundances. We use a five component analysis of the spectra using ferric iron oxide, ultrasmall ferric iron agglomorates a part of which are diamagnetic, paramagnetic ferrous high spin ions and two kinds of paramagnetic ferric high spin ions which were detected using EPR spectroscopy.