Giannis Mpourmpakis, Center for Catalytic Science and Technology, Department of Chemical Engineering, University of Delaware, Colburn lab, 150 Academy Street, Newark, DE 19716 and Dion Vlachos, Director of Center for Catalytic Science and Technology (CCST), University of Delaware, Newark, DE 19716.
First principle theoretical calculations have been performed to examine CO binding on all possible binding sites of gold clusters in the gas-phase and when supported on a MgO support. The gold clusters ranged in diameter from a few angstroms to approximately 1.5 nm. The largest systems are amenable only via novel quantum mechanical techniques described in our work. Our results concerning CO adsorption on gold clusters showed that suitable binding energy relations can be developed. Planar gold structures, when supported on MgO, slightly deform from their initial structural configuration, due to support-cluster interactions and the charge transferred from the support to the clusters. As a result, new physisorption sites are created on supported clusters for CO adsorption. CO chemisorption on gold clusters remains unaffected by the presence of the support. Our simulations isolate for the first time electronic from strain effects regarding CO binding on gold nanoparticles.