TY  - JOUR
AU  - Gan, L.
AU  - Cui, C.
AU  - Heggen, M.
AU  - Dionigi, F.
AU  - Rudi, S.
AU  - Strasser, P.
TI  - Element-specific anisotropic growth of shaped platinum alloy nanocrystals
JO  - Science
VL  - 346
IS  - 6216
SN  - 1095-9203
CY  - Washington, DC [u.a.]
PB  - American Association for the Advancement of Science64196
M1  - FZJ-2015-01615
SP  - 1502 - 1506
PY  - 2014
AB  - Morphological shape in chemistry and biology owes its existence to anisotropic growth and is closely coupled to distinct functionality. Although much is known about the principal growth mechanisms of monometallic shaped nanocrystals, the anisotropic growth of shaped alloy nanocrystals is still poorly understood. Using aberration-corrected scanning transmission electron microscopy, we reveal an element-specific anisotropic growth mechanism of platinum (Pt) bimetallic nano-octahedra where compositional anisotropy couples to geometric anisotropy. A Pt-rich phase evolves into precursor nanohexapods, followed by a slower step-induced deposition of an M-rich (M = Ni, Co, etc.) phase at the concave hexapod surface forming the octahedral facets. Our finding explains earlier reports on unusual compositional segregations and chemical degradation pathways of bimetallic polyhedral catalysts and may aid rational synthesis of shaped alloy catalysts with desired compositional patterns and properties. 
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000346536500061
C6  - pmid:25525243
DO  - DOI:10.1126/science.1261212
UR  - https://juser.fz-juelich.de/record/188154
ER  -