title: Visualization of oscillatory behaviour of Pt nanoparticles catalysing CO oxidation.
abstract: Many catalytic reactions under fixed conditions exhibit oscillatory behaviour. The oscillations are often attributed to dynamic changes in the catalyst surface. So far, however, such relationships were difficult to determine for catalysts consisting of supported nanoparticles. Here, we employ a nanoreactor to study the oscillatory CO oxidation catalysed by Pt nanoparticles using time-resolved high-resolution transmission electron microscopy, mass spectrometry and calorimetry. The observations reveal that periodic changes in the CO oxidation are synchronous with a periodic refacetting of the Pt nanoparticles. The oscillatory reaction is modelled using density functional theory and mass transport calculations, considering the CO adsorption energy and the oxidation rate as site-dependent. We find that to successfully explain the oscillations, the model must contain the phenomenon of refacetting. The nanoreactor approach can thus provide atomic-scale information that is specific to surface sites. This will improve the understanding of dynamic properties in catalysis and related fields.
authors.affiliation: ChemE, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands.
authors.forename: S B
authors.initials: SB
authors.lastname: Vendelbo
authors.affiliation: Haldor Topsøe A/S, Nymøllevej 55, DK-2800 Kgs. Lyngby, Denmark.
authors.forename: C F
authors.initials: CF
authors.lastname: Elkjær
authors.affiliation: Haldor Topsøe A/S, Nymøllevej 55, DK-2800 Kgs. Lyngby, Denmark.
authors.forename: H
authors.initials: H
authors.lastname: Falsig
authors.affiliation: ChemE, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands.
authors.forename: I
authors.initials: I
authors.lastname: Puspitasari
authors.affiliation: FEI Company, Achtseweg Noord 5, 5651 GG Eindhoven, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Dona
authors.affiliation: FEI Company, Achtseweg Noord 5, 5651 GG Eindhoven, The Netherlands.
authors.forename: L
authors.initials: L
authors.lastname: Mele
authors.affiliation: DIMES-ECTM, Delft University of Technology, PO Box 5053, 2600 GB Delft, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: Morana
authors.affiliation: Albemarle Catalyst Company BV, PO Box 37650, 1030 BE Amsterdam, The Netherlands.
authors.forename: B J
authors.initials: BJ
authors.lastname: Nelissen
authors.affiliation: Leiden Probe Microscopy BV, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: van Rijn
authors.affiliation: DIMES-ECTM, Delft University of Technology, PO Box 5053, 2600 GB Delft, The Netherlands.
authors.forename: J F
authors.initials: JF
authors.lastname: Creemer
authors.affiliation: ChemE, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands.
authors.forename: P J
authors.initials: PJ
authors.lastname: Kooyman
authors.affiliation: Haldor Topsøe A/S, Nymøllevej 55, DK-2800 Kgs. Lyngby, Denmark.
authors.forename: S
authors.initials: S
authors.lastname: Helveg