Formation of metallic nanoparticles produces an increased surface area per unit volume of material, which provides potential applications in enhancing surface catalyzed reactions. Recently, attention has been focused on moving from the solution based syntheses to solid phase materials by arranging such particles into well ordered 2- and 3- dimensional structures, or forming cluster engineered materials that posses well defined structures. Such studies have shown the importance of size, size distribution, and shape of particles upon self assembled monolayers. We have recently prepared shape-controlled Pt nanoparticles with ﹛111﹜ (tetrahedral), ﹛100﹜ (cubic), and mixed ﹛111﹜ - ﹛100﹜ (truncated octahedral) faces. To study how these faces may orient to form particle point superlattice structures we have prepared monolayer distributions of Pt particles in humidity chambers for analysis by TEM.

Our shape controlled Pt particle synthesis yields between 60 and 80 % cubes, tetrahedra, or truncated octahedra with average diameters ≥ 7 nm.