title: New Insights into the Nature of Co-components and Their Impact on Pd Structure: X-ray Absorption Studies on Toluene Acetoxylation Catalysts.
abstract: Co-components are a powerful tool to tune the performance of catalysts, but their nature and their impact on the catalysts is often controversially discussed. In this study X-ray absorption spectroscopy (XAS) was employed to elucidate the nature of co-components and their impact on the catalytic reaction. In anatase-supported Pd-based catalysts for the gas-phase acetoxylation of toluene, less noble co-components (e.g., Mn, Co, and Sb) spread over the support in their oxidic form and changed their valence state on stream. Incorporated atoms such as C or a small part of the Sb affect the electronic structure of Pd. For the noble Au, only a weak interaction with the support and Pd was observed during time on stream. Only XAS at the K-edges together with investigations of the Pd L-edge for a better understanding of the electronic structure, supplemented by STEM for elemental mapping, allow such detailed insights.
authors.affiliation: Electronic Structure and Magnetism, European Synchrotron Radiation Facility (ESRF), 71, avenue des Martyrs, 38000 Grenoble (France).
authors.forename: Suresh
authors.initials: S
authors.lastname: Gatla
authors.affiliation: Leibniz Institute for Catalysis at the University of Rostock, Albert-Einstein-Strasse 29a, 18059 Rostock (Germany). joerg.radnik@catalysis.de.
authors.forename: Jörg
authors.initials: J
authors.lastname: Radnik
authors.affiliation: Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (The Netherlands).
authors.forename: Neetika
authors.initials: N
authors.lastname: Madaan
authors.affiliation: Leibniz Institute for Catalysis at the University of Rostock, Albert-Einstein-Strasse 29a, 18059 Rostock (Germany).
authors.forename: Marga-Martina
authors.initials: MM
authors.lastname: Pohl
authors.affiliation: Electronic Structure and Magnetism, European Synchrotron Radiation Facility (ESRF), 71, avenue des Martyrs, 38000 Grenoble (France).
authors.forename: Olivier
authors.initials: O
authors.lastname: Mathon
authors.affiliation: Electronic Structure and Magnetism, European Synchrotron Radiation Facility (ESRF), 71, avenue des Martyrs, 38000 Grenoble (France).
authors.forename: Andrei
authors.initials: A
authors.lastname: Rogalev
authors.affiliation: Leibniz Institute for Catalysis at the University of Rostock, Albert-Einstein-Strasse 29a, 18059 Rostock (Germany).
authors.forename: Venkata
authors.initials: V
authors.lastname: Narayana Kalevaru
authors.affiliation: Leibniz Institute for Catalysis at the University of Rostock, Albert-Einstein-Strasse 29a, 18059 Rostock (Germany).
authors.forename: Andreas
authors.initials: A
authors.lastname: Martin
authors.affiliation: Electronic Structure and Magnetism, European Synchrotron Radiation Facility (ESRF), 71, avenue des Martyrs, 38000 Grenoble (France). sakura@esrf.fr.
authors.forename: Sakura
authors.initials: S
authors.lastname: Pascarelli
authors.affiliation: Leibniz Institute for Catalysis at the University of Rostock, Albert-Einstein-Strasse 29a, 18059 Rostock (Germany).
authors.forename: Angelika
authors.initials: A
authors.lastname: Brückner
keywords: X-ray absorption spectroscopy; catalyst co-components; heterogeneous catalysis; palladium; supported catalysts