Influence of Local Defects on the Dynamics of O-H Bond Breaking and Formation on a Magnetite Surface

Author(s)
Alexander Bourgund, Barbara A. J. Lechner, Matthias Meier, Cesare Franchini, Gareth S. Parkinson, Ueli Heiz, Friedrich Esch
Abstract

The transport of H adatoms across oxide supports plays an important role in many catalytic reactions. We investigate the dynamics of H/Fe3O4(001) between 295 and 382 K. By scanning tunneling microscopy at frame rates of up to 19.6 fps, we observe the thermally activated switching of H between two O atoms on neighboring Fe rows. This switching rate changes in proximity to a defect, explained by density functional theory as a distortion in the Fe-O lattice shortening the diffusion path. Quantitative analysis yields an apparent activation barrier of 0.94 +/- 0.07 eV on a pristine surface. The present work highlights the importance of local techniques in the study of atomic-scale dynamics at defective surfaces such as oxide supports.

Organisation(s)
Computational Materials Physics
External organisation(s)
Technische Universität München, Technische Universität Wien, Center for Computational Materials Science
Journal
Journal of Physical Chemistry C
Volume
123
Pages
19742-19747
No. of pages
6
ISSN
1932-7447
DOI
https://doi.org/10.1021/acs.jpcc.9b05547
Publication date
08-2019
Peer reviewed
Yes
Austrian Fields of Science 2012
Materials physics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/influence-of-local-defects-on-the-dynamics-of-oh-bond-breaking-and-formation-on-a-magnetite-surface(7323e8ce-5832-4e62-8eab-33b18cebfe40).html