title: Shape-controlled synthesis of Pt nanocrystals: the role of metal carbonyls.
abstract: Well-controlled synthesis of nanocrystals is necessary to unambiguously correlate the structural properties of nanocrystals with the catalytic properties. The most common low-index surfaces are (111) and (100). Therefore, model materials with {111} and {100} facets are highly desirable, in order to understand the catalytic properties of (111) and (100) surfaces for various structure-sensitive reactions. We report a solution-phase synthesis using metal carbonyls as additives. This synthetic method produces highly monodisperse Pt octahedra and icosahedra as the model of Pt{111}, Pt cubes as the model of Pt{100}, respectively. Several other morphologies, such as truncated cubes, cuboctahedra, spheres, tetrapods, star-shaped octapods, multipods, and hyper-branched structure, are produced, as well. A bifunctional role of metal carbonyl in the synthesis is identified: zerovalent transition metal decomposed from metal carbonyl acts as a shape-directing agent, while CO provides the reducing power. These high-quality shape-controlled Pt nanocrystals are suitable for model catalyst studies.
authors.affiliation: Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Yijin
authors.initials: Y
authors.lastname: Kang
authors.forename: Jun Beom
authors.initials: JB
authors.lastname: Pyo
authors.forename: Xingchen
authors.initials: X
authors.lastname: Ye
authors.forename: Rosa E
authors.initials: RE
authors.lastname: Diaz
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Gordon
authors.forename: Eric A
authors.initials: EA
authors.lastname: Stach
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Murray
mesh_terms: D002384:Catalysis; D003460:Crystallization / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D008968:Molecular Conformation; D010316:Particle Size; D010984:Platinum / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D010984:Platinum