Identification of Active Sites in Oxidation Reaction from Real-Time Probing of Adsorbate Motion over Pd Nanoparticles

Ahmed Ghalgaoui*, Ridha Horchani, Jijin Wang, Aimeric Ouvrard, Serge Carrez, Bernard Bourguignon

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

Obtaining insight into the type of surface sites involved in a reaction is essential to understand catalytic mechanisms at the atomic level and a key for understanding selectivity in surface-catalyzed reactions. Here we use ultrafast broad-band vibrational spectroscopy to follow in real-time diffusion of CO molecules over a palladium nanoparticle surface toward an active site. Site-to-site hopping is triggered by laser excitation of electrons and followed in real-time from subpicosecond changes in the vibrational spectra. CO photoexcitation occurs in 400 fs and hopping from NP facets to edges follows within ∼1 ps. Kinetic modeling allows to quantify the contribution of different facet sites to the catalytic reaction. These results provide useful insights for understanding the mechanism of chemical reactions catalyzed by metal NPs.

Original languageEnglish
Pages (from-to)5202-5206
Number of pages5
JournalJournal of Physical Chemistry Letters
Volume9
Issue number18
DOIs
Publication statusPublished - Sep 20 2018
Externally publishedYes

ASJC Scopus subject areas

  • Materials Science(all)
  • Physical and Theoretical Chemistry

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