Angewandte Chemie Journal
A dynamic structural behavior of Pt nanoparticles on the ceria surface under reducing/oxidizing conditions was found at moderate temperatures (<500°C) and exploited to enhance the catalytic activity of Pt/CeO2-based exhaust gas catalysts. Redispersion of platinum in an oxidizing atmosphere already occurred at 400°C. A protocol with reducing pulses at 250–400°C was applied in a subsequent step for controlled Pt-particle formation. Operando X-ray absorption spectroscopy unraveled the different extent of reduction and sintering of Pt particles: the choice of the reductant allowed the tuning of the reduction degree/particle size and thus the catalytic activity (CO>H2>C3H6). This dynamic nature of Pt on ceria at such low temperatures (250-500°C) was additionally confirmed by in situ environmental transmission electron microscopy. A general concept is proposed to adjust the noble metal dispersion (size, structure), for example, during operation of an exhaust gas catalyst.
For details:
Tuning the structure of platinum particles on ceria In situ for enhancing the catalytic performance of exhaust gas catalysts
Andreas M. Gänzler a, Dr. Maria Casapu a, Dr. Philippe Vernoux b, Dr. Stéphane Loridant b, Dr. Francisco J. Cadete Santos Aires b, Dr. Thierry Epicier c, Benjamin Betz d,e, Dr. Rüdiger Hoyer d, Prof. Dr. Jan-Dierk Grunwaldt a
a. Institute for Chemical Technology and Polymer Chemistry (ITCP), Karlsruhe Institute of Technology (KIT), Engesserstr. 20, 76131 Karlsruhe, Germany
b. Institut de Recherches sur la Catalyse et l’Environnement de Lyon, UMR 5256, CNRS, Université Claude Bernard Lyon 1, Université de Lyon, 2 Avenue Albert Einstein, 69626 Villeurbanne, France
c. Matériaux, Ingénierie et Science, UMR 5510, CNRS, INSA de Lyon, Université de Lyon, 2 Avenue Albert Einstein, 69626 Villeurbanne, France
d. Umicore AG & Co. KG, Rodenbacher Chaussee 4, 63457 Hanau, Germany
e. Ernst-Berl Institut, Technische Universität Darmstadt, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany
Angewandte Chemie, Volume 56, Issue 42
https://doi.org/10.1002/anie.201707842
© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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