title: An operando emission spectroscopy study of Pt/Al2O3and Pt/CeO2/Al2O3.
abstract: In situ time-resolved spectroscopic examination of catalysts based on well dispersed nanoparticles on metal oxides under transient conditions significantly facilitates the elucidation of reaction mechanisms. In this contribution, we demonstrate the level of structural information that can be obtained using high-energy resolution off-resonant spectroscopy (HEROS) to study 1.3 wt% Pt/Al2O3and 1.3 wt% Pt/20 wt% CeO2/Al2O3catalysts subjected to redox pulsing. First, HEROS is compared with XANES in a temperature programmed reduction experiment to demonstrate the increased sensitivity and time resolution of HEROS. Second, modulation excitation spectroscopy is exploited by redox pulsing to enhance the sensitivity of HEROS to structural changes by the application of phase sensitive detection (PSD) to the time-resolved HEROS data set. The HEROS measurements were complemented by resonant X-ray emission (RXES) and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy measurements performed under identical conditions and in a single reactor cell in order to probe different aspects of the catalyst materials under the selected experimental conditions.
authors.affiliation: Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland. davide.ferri@psi.ch and ETH Zurich, Institute for Chemical and Bioengineering, CH-8093 Zurich, Switzerland.
authors.forename: Valentina
authors.initials: V
authors.lastname: Marchionni
authors.affiliation: Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland. davide.ferri@psi.ch and Jan Kochanowski University, Institute of Physics, PL-25-406 Kielce, Poland.
authors.forename: Jakub
authors.initials: J
authors.lastname: Szlachetko
authors.affiliation: Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland. davide.ferri@psi.ch.
authors.forename: Maarten
authors.initials: M
authors.lastname: Nachtegaal
authors.affiliation: Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland. davide.ferri@psi.ch.
authors.forename: Anastasios
authors.initials: A
authors.lastname: Kambolis
authors.affiliation: Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland. davide.ferri@psi.ch and École polytechnique fédérale de Lausanne (EPFL), Institute of Chemical Science and Engineering, CH-1015 Lausanne, Switzerland.
authors.forename: Oliver
authors.identifier: http://orcid.org/0000-0002-7268-7257
authors.initials: O
authors.lastname: Kröcher
authors.affiliation: Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland. davide.ferri@psi.ch.
authors.forename: Davide
authors.identifier: http://orcid.org/0000-0002-9354-5231
authors.initials: D
authors.lastname: Ferri