Solved and Unsolved Cases of Transition Metal Cluster Surface Morphologies and Activities

We are investigating the surface morphology and adsorbate bonding properties of naked transition metal clusters under cryo conditions, and we have conducted a series of spectroscopic, kinetic and computational studies of the N₂ adsorption onto size selected Cobalt and Nickel clusters [1-4], as well as a case study of N₂ and H₂ co-adsorption onto a selected Ruthenium cluster [5]. In the course of these studies we chose to investigate Iron clusters and Iron-Rhodium nanoalloys as well. We found some Iron clusters reluctant to attach neither Nitrogen N₂ nor Hydrogen H₂. This presentation puts the current level of understanding to the stage.

[1] S. Dillinger, J. Mohrbach, J. Hewer, M. Gaffga, and G. Niedner-Schatteburg, Infrared spectroscopy of N₂ adsorption on size selected cobalt cluster cations in isolation, PCCP 17 (2015) 10358.
[2] J. Mohrbach, S. Dillinger, and G. Niedner-Schatteburg, Cryo Kinetics and Spectroscopy of Cationic Nickel Clusters: Rough and Smooth Surfaces, J. Phys. Chem. C 121 (2017) 10907.
[3] J. Mohrbach, S. Dillinger, and G. Niedner-Schatteburg, Probing cluster surface morphology by cryo kinetics of N₂ on cationic nickel clusters, J. Chem. Phys. 147, 184304 (2017) 184304.
[4] S. Dillinger, J. Mohrbach, and G. Niedner-Schatteburg, Probing cluster surface morphology by cryo spectroscopy of N₂ on cationic nickel clusters, J. Chem. Phys. 147, 184305 (2017) 184305.
[5] S. Dillinger, M. P. Klein, A. Steiner, D. C. McDonald, M. A. Duncan, M. M. Kappes, and G. Niedner-Schatteburg, Cryo IR Spectroscopy of N₂ and H₂ on Ru₈⁺: The Effect of N₂ on the H-Migration, J. Phys. Chem. Lett. 9 (2018) 914.