Nanoclusters on graphene/Ir(111): insights from ab-initio calculations and experiments

Fatema Mohamed1, Nicola Podda1, Manuel Corva1, Zhijing Feng1, Carlo Dri1, Erik Vesselli1,2 and Maria Peressi1,2,3

1.University of Trieste, Department of Physics, Via Valerio 2, Trieste, Italy

2.IOM-CNR, Trieste, Italy

3.INSTM, Unita’ di ricerca di Trieste, Italy

Fabrication of ordered arrays of metallic nanoclusters (NCs) for catalysis applications is the goal of many efforts. The Moire’ pattern of graphene/Ir(111) works as an efficient template to this purpose, in particular for the growth of Pt and Ir based NCs, as predicted by ab-initio calculations and observed for different metal loadings. The chemical and morphological behavior of metallic NCs upon interaction with small molecules of environmental importance such as carbon mono- and dioxide is investigated with atomic-level detail from ultra-high vacuum to near ambient pressure by both spectroscopy and microscopy approaches.

Ab initio calculations give insights into the different nucleation behavior of Pt and Ir with respect to other metals, such as for instance Cu, and predict that even materials that do not form cluster superlattices can be grown promoting their nucleation through a seeding mechanism with another properly chosen metal.

Support from the Italian Ministry of Foreign Affairs and International Cooperation (MAECI), MIUR, and the University of Trieste (Finanziamento di Ateneo per progetti di ricerca scientifica – FRA2015) is acknowledged.