Role of Polarons in Single-Atom Catalysts

Autor(en)

Panukorn Sombut, Lena Puntscher, Marlene Atzmueller, Zdenek Jakub, Michele Reticcioli, Matthias Meier, Gareth S. Parkinson, Cesare Franchini

Abstrakt

The local environment of metal-oxide supported single-atom catalysts plays a decisive role in the surface reactivity and related catalytic properties. The study of such systems is complicated by the presence of point defects on the surface, which are often associated with the localization of excess charge in the form of polarons. This can affect the stability, the electronic configuration, and the local geometry of the adsorbed adatoms. In this work, through the use of density functional theory and surface-sensitive experiments, we study the adsorption of Rh1, Pt1, and Au1 metals on the reduced TiO2(110) surface; a prototypical polaronic material. A systematic analysis of the adsorption configurations and oxidation states of the adsorbed metals reveals different types of couplings between adsorbates and polarons. As confirmed by scanning tunneling microscopy measurements, the favored Pt1 and Au1 adsorption at oxygen vacancy sites is associated with a strong electronic charge transfer from polaronic states to adatom orbitals, which results in a reduction of the adsorbed metal. In contrast, the Rh1 adatoms interact weakly with the excess charge, which leaves the polarons largely unaffected. Our results show that an accurate understanding of the properties of single-atom catalysts on oxide surfaces requires a careful account of the interplay between adatoms, vacancy sites, and polarons.

Organisation(en)

Computergestützte Materialphysik

Externe Organisation(en)

Technische Universität Wien, Università di Bologna

Journal

Topics in Catalysis

Band

65

Seiten

1620–1630

Anzahl der Seiten

11

ISSN

1022-5528

DOI

https://doi.org/10.1007/s11244-022-01651-0

Publikationsdatum

2022

Peer-reviewed

Ja

ÖFOS 2012

103009 Festkörperphysik

Schlagwörter

ASJC Scopus Sachgebiete

Allgemeine Chemie, Catalysis

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/4aba04a1-d751-4054-bb5a-863a1a20c88c