Atomic-Scale View of the Oxidation and Reduction of Supported Ultrathin FeO Islands

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DOI

By means of scanning tunneling microscopy (STM) measurements, we studied in situ the oxidation and reduction of FeO bilayer islands on Au(111) by oxygen (O2) and hydrogen (H2), respectively. The FeO islands respond very dynamically toward O2, with the coordinatively unsaturated ferrous (CUF) sites at the island edges being essential for O2 dissociation and O atom incorporation. An STM movie obtained during oxidation reveals how further O2 molecules can dissociate after the consumption of all initially existing CUF sites through the formation of new CUF sites. In contrast, we found that H2 molecules only dissociate when vibrationally excited through the ion gauge and only at the basal plane of FeO islands, implying that the CUF sites are not relevant for H2 dissociation. Our STM results reveal how excess O atoms are incorporated and released in O2 and H2 and thus shed light onto the stability of inverse catalysts during a catalyzed reaction.

Original languageEnglish
JournalACS Nano
Volume13
Issue10
Pages (from-to)11632-11641
Number of pages10
ISSN1936-0851
DOIs
Publication statusPublished - Oct 2019

    Research areas

  • catalysis, dissociation, H, iron oxide, O adatom dislocation lines, O, STM movies

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