Atomic control of ultrafine gold particles on mgo(100) as investigated by molecular dynamics and computer graphics

The applicability of our new molecular dynamics code to the design of highly dispersed ultrafine Au particles on an MgO(100) plane, which is essential for the maximum catalytic performance, was demonstrated. Although onlya single large Au cluster was formed on a smooth MgO(100) plane, two Au clusters were formed on an MgO(100)plane with either two point defects or two monoatomic steps at 300 K, since a single trapped Au atom in eachdefect site played a role of the nucleation center. These results suggested that the artificial construction of defectson the MgO(100) plane is desirable for realizing the ultrafine dispersion of Au particles. Furthermore, two Auclusters just over the surface step sites did not aggregate even at high temperatures, such as 700 K. Thus, it wasalso revealed that the surface defects are effective for inhibiting the sintering of Au clusters on the MgO(100)plane, which is essential for preventing catalyst deactivation.