Berlin 2024 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 8: Surface Reactions

O 8.1: Vortrag

Montag, 18. März 2024, 10:30–10:45, MA 141

Reactivity of single metal atoms in different coordination environments — •Nan Cao, Longfeng Huang, Johannes V. Barth, and Alexander Riss — Physics Department E20, Technical University of Munich, 85748 Garching, Germany

Metal centers within metalorganic networks hold promise for applications in single-atom catalysis, gas storage and sensing. Their activity is not only determined by the chemical nature of the metal, but is also significantly influenced by the bonding configuration. It is of fundamental scientific and technological relevance to understand how the reactivity of these sites can be controlled via chemical design.

In this work we present direct measurements of the interaction forces of single metal atoms¹ in different metalorganic coordination environments via atomic-scale atomic force microscopy (AFM) experiments. In particular, we examine how the interaction of metal sites with different types of probe atoms (directly attached to the AFM tip) changes as a function of their bonding configuration. Our measurements show that while chemically relatively inert CO-functionalization yields little discrimination between metal centers in different environments, Cl-functionalization gives rise to significant differences: low-coordinated metal atoms exhibit notably stronger interactions with the probe atom.

Such atomic-scale studies provide means to characterize active sites within complex metalorganic architectures, thus aiding in a rational design strategy toward materials with tailored catalytic properties.
[1]Science 2019, 366, 235-238; J. Phys. Rev. Lett. 2020, 124, 096001.

Keywords: Reactivity; Single metal atoms; Metal-organic networks