Journal Article

FZJ-2016-00225

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Thermal Facet Healing of Concave Octahedral Pt–Ni Nanoparticles Imaged in Situ at the Atomic Scale: Implications for the Rational Synthesis of Durable High-Performance ORR Electrocatalysts

Gan, L. ; Heggen, M.FZJ* ; Cui, C. ; Strasser, P. (Corresponding author)

2015
ACS Washington, DC

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Please use a persistent id in citations: doi:10.1021/acscatal.5b02620

Abstract: We performed in situ transmission electron microscopy of phase-segregated octahedral Pt–Ni alloy fuel cell nanocatalysts under thermal annealing to study their morphological stability and surface compositional evolution. The pristine octahedral Pt–Ni nanoparticles (NPs) showed Pt-rich corners/edges and slightly concave Ni-rich {111} facets. Time-resolved image series unequivocally revealed that upon annealing up to 500 °C, the Pt-rich surface atoms at the corners/edges diffused onto and subsequently covered the concave Ni-rich {111} surfaces, leading to perfectly flat Pt-rich {111} surfaces with Ni-rich subsurface layers. This was further corroborated by in situ aberration-corrected scanning transmission electron microscopy and electron energy loss spectroscopy. Our results propose a feasible approach to construct shaped Pt alloy nanoparticles with Pt-rich {111} surfaces and Ni-rich subsurface layers that are expected to be catalytically active and stable for the oxygen reduction reaction, thus providing important implications for rational synthesis of durably highly active shaped Pt alloy fuel cell electrocatalysts.

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Contributing Institute(s):

1. Mikrostrukturforschung (PGI-5)

Research Program(s):

1. 143 - Controlling Configuration-Based Phenomena (POF3-143) (POF3-143)

Appears in the scientific report 2015

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Database coverage:
; Current Contents - Physical, Chemical and Earth Sciences ; IF >= 5 ; JCR ; NCBI Molecular Biology Database ; No Authors Fulltext ; SCOPUS ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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