Shape-Controlled Synthesis of Pt Nanocrystals: The Role of Metal Carbonyls

• Published in: ACS nano Vol. 7; no. 1; pp. 645 - 653
• Main Authors: Kang, Yijin, Pyo, Jun Beom, Ye, Xingchen, Diaz, Rosa E, Gordon, Thomas R, Stach, Eric A, Murray, Christopher B
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 22.01.2013
• Subjects: Catalysis; Catalysts; Crystallization - methods; Cubes; Macromolecular Substances - chemistry; Materials Testing; Metal carbonyls; Metal Nanoparticles - chemistry; Metal Nanoparticles - ultrastructure; Molecular Conformation; Nanocrystals; Nanostructure; Particle Size; Platinum; Platinum - chemistry; Surface Properties; Synthesis; Transition metals; nanocrystal; platinum; shape control; morphology; CO oxidation; catalysis; electrocatalysis
• DOI: 10.1021/nn3048439
• ISSN: 1936-0851

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.