STEPS, LEDGES AND KINKS ON THE SURFACES OF PLATINUM NANOPARTICLES OF DIFFERENT SHAPES

Platinum nanoparticles with a high percentage of cubic-, tetrahedral- and octahedral-like shapes, respectively, have been synthesized by a s hape-controlling technique that we developed recently [Ahmadi et al., Science 272 (June 1996) 1924]. High resolution transmission electron m icroscopy (HRTEM) is used here to directly image the atomic scale stru ctures of the surfaces of these particles with different shapes. The t runcated shapes of these particles are mainly defined by the {100}, {1 11}, and {110} facets, on which numerous atom-high surface steps, ledg es and kinks have been observed. This atomic-scale fine structure of t he surfaces of these particles is expected to play a critical role in their catalytic activity and selectivity. (C) 1997 Elsevier Science B. V.