Ligand coordination effects on gallium nanocluster reactivity

Stabilisation and modulation of nanocluster reactivity are key elements for the development of these materials as versatile and selective catalysts. This study presents a preliminary investigation of the interaction of ligands with a gallium nanocluster (Ga13). The amphoteric nature of Ga13 means that both a Lewis base (NH3) and a Lewis acid (BH3) strongly adsorb to the surface of the cluster. More importantly, ligand coordination modifies the electronic structure of the cluster, leading to an enhancement of reactivity. In particular, NH3 coordination was found to lower the energy barrier for H2 chemisorption by 10% and BH3 coordination led to reduction of the barrier by 20%. These results demonstrate the potential for ligand coordination as a means of accelerating reactions on cluster surfaces.