CO-Induced Dimer Decay Responsible for Gem-Dicarbonyl Formation on a Model Single-Atom Catalyst

Wang, Chunlei; Sombut, Panukorn; Puntscher, Lena; Jakub, Zdeněk; Meier, Matthias; Pavelec, Jiří; Bliem, Roland; Schmid, Michael; Diebold, Ulrike; Franchini, Cesare; Parkinson, Gareth S.

CO-Induced Dimer Decay Responsible for Gem-Dicarbonyl Formation on a Model Single-Atom Catalyst

Files

AngewChemIntEd2024Wang.pdf(1.09 MB)

Date

2024-04-15

Authors

Wang, Chunlei

Sombut, Panukorn

Puntscher, Lena

Jakub, Zdeněk

Meier, Matthias

Pavelec, Jiří

Bliem, Roland

Schmid, Michael

Diebold, Ulrike

Franchini, Cesare

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ORCID

0000-0001-9538-9087

Publisher

WILEY-V C H VERLAG GMBH

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Abstract

The ability to coordinate multiple reactants at the same active site is important for the wide-spread applicability of single-atom catalysis. Model catalysts are ideal to investigate the link between active site geometry and reactant binding, because the structure of single-crystal surfaces can be precisely determined, the adsorbates imaged by scanning tunneling microscopy (STM), and direct comparisons made to density functional theory. In this study, we follow the evolution of Rh1 adatoms and minority Rh2 dimers on Fe3O4(001) during exposure to CO using time-lapse STM at room temperature. CO adsorption at Rh1 sites results exclusively in stable Rh1CO monocarbonyls, because the Rh atom adapts its coordination to create a stable pseudo-square planar environment. Rh1(CO)2 gem-dicarbonyl species are also observed, but these form exclusively through the breakup of Rh2 dimers via an unstable Rh2(CO)3 intermediate. Overall, our results illustrate how minority species invisible to area-averaging spectra can play an important role in catalytic systems, and show that the decomposition of dimers or small clusters can be an avenue to produce reactive, metastable configurations in single-atom catalysis. Time-lapse scanning tunneling microscopy movies are combined with theoretical computations to study CO adsorption on a model Rh1/Fe3O4(001) catalyst under ultrahigh vacuum conditions. Direct CO adsorption at Rh1 sites results in monocarbonyl species. Rh1-(CO)2 gem dicarbonyl species are observed, but from only via the CO-induced break-up of Rh2 dimer species.+ image

Keywords

Scanning tunneling microscopy, single-atom catalysis, density functional theory, metal-oxide surfaces

Citation

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION. 2024, vol. 63, issue 16, 8 p.
https://onlinelibrary.wiley.com/doi/10.1002/anie.202317347

Document type

Peer-reviewed

Document version

Published version

Language of document

en

Document licence

Creative Commons Attribution 4.0 International
http://creativecommons.org/licenses/by/4.0/