Steric Hindrance of NH3Diffusion on Pt(111) by Co-Adsorbed O-Atoms

Dmitriy Borodin, Oihana Galparsoro, Igor Rahinov, Jan Fingerhut, Michael Schwarzer, Stefan Hörandl, Daniel J. Auerbach, Alexander Kandratsenka, Dirk Schwarzer, Theofanis N. Kitsopoulos, Alec M. Wodtke

Research output: Contribution to journalArticlepeer-review


A detailed velocity-resolved kinetics study of NH3 thermal desorption rates from p(2 × 2) O/Pt(111) is presented. We find a large reduction in the NH3 desorption rate due to adsorption of O-atoms on Pt(111). A physical model describing the interactions between adsorbed NH3 and O-atoms explains these observations. By fitting the model to the derived desorption rate constants, we find an NH3 stabilization on p(2 × 2) O/Pt(111) of 0.147-0.014+0.023 eV compared to Pt(111) and a rotational barrier of 0.084-0.022+0.049 eV, which is not present on Pt(111). The model also quantitatively predicts the steric hindrance of NH3 diffusion on Pt(111) due to co-adsorbed O-atoms. The derived diffusion barrier of NH3 on p(2 × 2) O/Pt(111) is 1.10-0.13+0.22 eV, which is 0.39-0.14+0.22 eV higher than that on pristine Pt(111). We find that Perdew Burke Ernzerhof (PBE) and revised Perdew Burke Ernzerhof (RPBE) exchange-correlation functionals are unable to reproduce the experimentally observed NH3-O adsorbate-adsorbate interactions and NH3 binding energies at Pt(111) and p(2 × 2) O/Pt(111), which indicates the importance of dispersion interactions for both systems.

Original languageEnglish
Pages (from-to)21791-21799
Number of pages9
JournalJournal of the American Chemical Society
Issue number47
StatePublished - 30 Nov 2022

Bibliographical note

Funding Information:
D.B., J.F., A.K., and T.N.K. acknowledge support from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement no. [833404]). O.G. acknowledges financial support by the Spanish Ministerio de Ciencia e Innovación [Grant no. PID2019-107396GB-I00/AEI/10.13039/501100011033]. I.R. gratefully acknowledges the support by Israel Science Foundation, ISF (grant No. 2187/19), and by the Open University of Israel Research Authority (grant No. 31044). M.S. thanks the BENCh graduate school, funded by the DFG (389479699/GRK2455).

Funding Information:
Open access funded by Max Planck Society.

Publisher Copyright:
© 2022 The Authors. Published by American Chemical Society.


  • Adsorption
  • Diffusion
  • Kinetics


Dive into the research topics of 'Steric Hindrance of NH3Diffusion on Pt(111) by Co-Adsorbed O-Atoms'. Together they form a unique fingerprint.

Cite this