A Multitechnique Study of C₂H₄ Adsorption on a Model Single-Atom Rh₁ Catalyst

Author(s)

Chunlei Wang, Panukorn Sombut, Lena Puntscher, Manuel Ulreich, Jiri Pavelec, David Rath, Jan Balajka, Matthias Meier, Michael Schmid, Ulrike Diebold, Cesare Franchini, Gareth S. Parkinson

Abstract

Single-atom catalysts are potentially ideal model systems to investigate structure-function relationships in catalysis if the active sites can be uniquely determined. In this work, we study the interaction of C2H4 with a model Rh/Fe3O4(001) catalyst that features 2-, 5-, and 6-fold coordinated Rh adatoms, as well as Rh clusters. Using multiple surface-sensitive techniques in combination with calculations of density functional theory (DFT), we follow the thermal evolution of the system and disentangle the behavior of the different species. C2H4 adsorption is strongest at the 2-fold coordinated Rh1 with a DFT-determined adsorption energy of −2.26 eV. However, desorption occurs at lower temperatures than expected because the Rh migrates into substitutional sites within the support, where the molecule is more weakly bound. The adsorption energy at the 5-fold coordinated Rh sites is predicated to be −1.49 eV, but the superposition of this signal with that from small Rh clusters and additional heterogeneity leads to a broad C2H4 desorption shoulder in TPD above room temperature.

Organisation(s)

Computational Materials Physics

External organisation(s)

Technische Universität Wien, University of Bologna

Journal

Journal of Physical Chemistry C

Volume

128

Pages

15404-15411

No. of pages

8

ISSN

1932-7447

DOI

https://doi.org/10.1021/acs.jpcc.4c03588

Publication date

09-2024

Peer reviewed

Yes

Austrian Fields of Science 2012

103020 Surface physics, 103043 Computational physics, 104017 Physical chemistry

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials, Energy(all), Physical and Theoretical Chemistry, Surfaces, Coatings and Films

Portal url

https://ucrisportal.univie.ac.at/en/publications/a-multitechnique-study-of-c2h4-adsorption-on-a-model-singleatom-rh1-catalyst(e879e7cf-53c6-4e56-ab6d-d2cb035e9ae3).html