Catalytic Role of Au Nanowires

The oxidation of CO in linear atomic chains (LACs) of Au nanowires (NW) is studied by means of density functional theory calculations using quasi-static (T=0) and finite temperature {\it ab initio} molecular dynamics simulations. The adsorption of O$_2$ and CO molecules on the LAC lead to the formation of an intermediate O$_2$CO complex. Upon thermal activation at room temperature, the complex is able to proceed to oxidation forming a CO$_2$ molecule and leaving an atomic O impurity into the Au LAC. We report the conditions under which this oxidation pathway takes place. This process also explains the appearance of unusual large Au-Au bond distances in the LAC and attributed to the presence of atomic impurities.