Operando XANES Reveals the Chemical State of Iron-Oxide Monolayers During Low-Temperature CO Oxidation
Artikel i vetenskaplig tidskrift, 2025

We have used grazing incidence X-ray absorption near edge spectroscopy (XANES) to investigate the behavior of monolayer FeO x ${_x }$ films on Pt(111) under near ambient pressure CO oxidation conditions with a total gas pressure of 1 bar. Spectra indicate reversible changes during oxidation and reduction by O 2 ${_2 }$ and CO at 150 degrees C, attributed to a transformation between FeO bilayer and FeO 2 ${_2 }$ trilayer phases. The trilayer phase is also reduced upon heating in CO+O 2 ${_2 }$ , consistent with a Mars-van-Krevelen type mechanism for CO oxidation. At higher temperatures, the monolayer film dewets the surface, resulting in a loss of the observed reducibility. A similar iron oxide film prepared on Au(111) shows little sign of reduction or oxidation under the same conditions. The results highlight the unique properties of monolayer FeO and the importance of the Pt support in this reaction. The study furthermore demonstrates the power of grazing-incidence XAFS for in situ studies of these model catalysts under realistic conditions.

Iron oxide

Heterogeneous catalysis

Thin films

Operando

XAFS

Visa alla personer

Publicerad i

ChemPhysChem

1439-4235 (ISSN) 1439-7641 (eISSN)

Vol. 26 Nummer/häfte 2 art. nr e202400835

Forskningsprojekt

Utveckling av röntgentekniker och nya Ga-zeotyper för produktion av gröna aromater

Vetenskapsrådet (VR) (2023-06344), 2024-01-01 -- 2027-12-31.

Kategorisering

Ämneskategorier (SSIF 2011)

Den kondenserade materiens fysik

Identifikatorer

DOI

10.1002/cphc.202400835

PubMed

39403857

Mer information

Senast uppdaterat

2025-03-28