Small molecule binding to surface-supported single-site transition-metal reaction centres

• Published in: Nature communications Vol. 13; no. 1; p. 7407
• Main Authors: DeJong, M., Price, A. J. A., Mårsell, E., Tom, G., Nguyen, G. D., Johnson, E. R., Burke, S. A.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.12.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 147/136; 147/138; 639/638/542/968; 639/638/77/887; Atomic force microscopy; Catalysts; Density functional theory; Humanities and Social Sciences; Intermediates; Iron; Low temperature; Microscopy; multidisciplinary; Reaction mechanisms; Scanning tunneling microscopy; Science; Science (multidisciplinary); Silver; Spectroscopy; Substrates; Transition metals; Ultrahigh temperature
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-35193-6

Despite dominating industrial processes, heterogeneous catalysts remain challenging to characterize and control. This is largely attributable to the diversity of potentially active sites at the catalyst-reactant interface and the complex behaviour that can arise from interactions between active sites. Surface-supported, single-site molecular catalysts aim to bring together benefits of both heterogeneous and homogeneous catalysts, offering easy separability while exploiting molecular design of reactivity, though the presence of a surface is likely to influence reaction mechanisms. Here, we use metal-organic coordination to build reactive Fe-terpyridine sites on the Ag(111) surface and study their activity towards CO and C 2 H 4 gaseous reactants using low-temperature ultrahigh-vacuum scanning tunnelling microscopy, scanning tunnelling spectroscopy, and atomic force microscopy supported by density-functional theory models. Using a site-by-site approach at low temperature to visualize the reaction pathway, we find that reactants bond to the Fe-tpy active sites via surface-bound intermediates, and investigate the role of the substrate in understanding and designing single-site catalysts on metallic supports. Surface-supported metalorganics promise the best of homogenous and heterogeneous catalysts. Here the authors show that small molecules bind to an iron-terpyridine site on silver via surface bound intermediates by following molecules one at a time.