Catalytic Oxidation of Carbon Monoxide on a Curved Pd Crystal: Spatial Variation of Active and Poisoning Phases in Stationary Conditions

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

Understanding nanoparticle catalysis requires novel approaches in which adjoining crystal orientations can be studied under the same reactive conditions. Here we use a curved palladium crystal and near-ambient pressure X-ray photoemission spectroscopy to characterize chemical species during the catalytic oxidation of CO in a whole set of surfaces vicinal to the (111) direction simultaneously. By stabilizing the reaction at fixed temperatures around the ignition point, we observe a strong variation of the catalytic activity across the curved surface. Such spatial modulation of the reaction stage is straightforwardly mapped through the photoemission signal from active oxygen species and poisoning CO, which are shown to coexist in a transient regime that depends on the vicinal angle. Line-shape analysis and direct comparison with ultrahigh vacuum experiments help identifying and quantifying all such surface species, allowing us to reveal the presence of surface oxides during reaction ignition and cooling-off.

Detaljer

Författare
Enheter & grupper
Externa organisationer
  • CSIC Centro de Física de Materiales (UPV/EHU)
  • National University of General San Martín
  • CSIC Instituto de Ciencia de Materiales de Madrid (ICMM)
  • Donostia International Physics Center (DIPC)
  • ALBA Synchrotron Light Facility
  • University of the Basque Country
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Kemiteknik
Originalspråkengelska
Sidor (från-till)16245-16252
Antal sidor8
TidskriftJournal of the American Chemical Society
Volym140
Utgivningsnummer47
StatusPublished - 2018
PublikationskategoriForskning
Peer review utfördJa