TY  - JOUR
AU  - Shviro, Meital
AU  - Gocyla, Martin
AU  - Polani, Shlomi
AU  - Heggen, Marc
AU  - Zitoun, David
AU  - Dunin‐Borkowski, Rafal E.
TI  - Morphological, Structural, and Compositional Evolution of Pt–Ni Octahedral Electrocatalysts with Pt‐Rich Edges and Ni‐Rich Core: Toward the Rational Design of Electrocatalysts for the Oxygen Reduction Reaction
JO  - Particle & particle systems characterization
VL  - 36
IS  - 3
SN  - 0176-2265
CY  - Weinheim
PB  - Wiley-VCH
M1  - FZJ-2020-02976
SP  - 1800442 -
PY  - 2019
AB  - The progress in colloidal synthesis of Pt–Ni octahedra has been instrumental in rising the oxygen reduction reaction catalytic activity high above the benchmark of Pt catalysts. This impressive catalytic performance is believed to result from the exposure of the most active catalytic sites after an activation process, chemical or electrochemical, which leads to a Pt surface enrichment. A foremost importance is to understand the structure and the elemental distribution of Pt–Ni octahedral, which leads to an optimal catalytic activity and stability. However, the factors governing the synthesis of the Pt–Ni octahedra are not well understood. In this study, unprecedented surface atomic segregation of Pt atoms in a Ni‐rich Pt–Ni octahedral nanoparticle structure is established by advanced electron microscopy. The Pt atoms are almost exclusively located on the edges of the Pt–Ni octahedra. This structure is formed in a pristine form, i.e., prior to any chemical or electrochemical etching. A new growth mechanism is revealed, which involves the transformation from an octahedron with a Pt‐rich core to a Ni‐rich octahedron with Pt‐rich edges. This observation may pave the way for a deeper understanding of this class of Pt–Ni octahedral nanoparticles as an electrocatalyst.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000461878400005
DO  - DOI:10.1002/ppsc.201800442
UR  - https://juser.fz-juelich.de/record/878655
ER  -