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Title: In Situ Study of Atomic Structure Transformations of Pt-Ni Nanoparticle Catalysts during Electrochemical Potential Cycling

Abstract

When exposed to corrosive anodic electrochemical environments, Pt alloy nanoparticles (NPs) undergo selective dissolution of the less noble component, resulting in catalytically active bimetallic Pt-rich core–shell structures. Structural evolution of PtNi 6 and PtNi 3 NP catalysts during their electrochemical activation and catalysis was studied by in situ anomalous small-angle X-ray scattering to obtain insight in element-specific particle size evolution and time-resolved insight in the intraparticle structure evolution. Ex situ high-energy X-ray diffraction coupled with pair distribution function analysis was employed to obtain detailed information on the atomic-scale ordering, particle phases, structural coherence lengths, and particle segregation. Our studies reveal a spontaneous electrochemically induced formation of PtNi particles of ordered Au 3Cu-type alloy structures from disordered alloy phases (solid solutions) concomitant with surface Ni dissolution, which is coupled to spontaneous residual Ni metal segregation during the activation of PtNi 6. Pt-enriched core–shell structures were not formed using the studied Ni-rich nanoparticle precursors. In contrast, disordered PtNi 3 alloy nanoparticles lose Ni more rapidly, forming Pt-enriched core–shell structures with superior catalytic activity. Our X-ray scattering results are confirmed by STEM/EELS results on similar nanoparticles.

Authors:
; ; ; ;  [1]
  1. CMU
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
FOREIGN
OSTI Identifier:
1089578
Resource Type:
Journal Article
Journal Name:
ACS Nano
Additional Journal Information:
Journal Volume: 7; Journal Issue: (7) ; 07, 2013; Journal ID: ISSN 1936-0851
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
ENGLISH

Citation Formats

Tuaev, Xenia, Rudi, Stefan, Petkov, Valeri, Hoell, Armin, Strasser, Peter, TU Berlin), and Twente). In Situ Study of Atomic Structure Transformations of Pt-Ni Nanoparticle Catalysts during Electrochemical Potential Cycling. United States: N. p., 2013. Web. doi:10.1021/nn402406k.
Tuaev, Xenia, Rudi, Stefan, Petkov, Valeri, Hoell, Armin, Strasser, Peter, TU Berlin), & Twente). In Situ Study of Atomic Structure Transformations of Pt-Ni Nanoparticle Catalysts during Electrochemical Potential Cycling. United States. doi:10.1021/nn402406k.
Tuaev, Xenia, Rudi, Stefan, Petkov, Valeri, Hoell, Armin, Strasser, Peter, TU Berlin), and Twente). Wed . "In Situ Study of Atomic Structure Transformations of Pt-Ni Nanoparticle Catalysts during Electrochemical Potential Cycling". United States. doi:10.1021/nn402406k.
@article{osti_1089578,
title = {In Situ Study of Atomic Structure Transformations of Pt-Ni Nanoparticle Catalysts during Electrochemical Potential Cycling},
author = {Tuaev, Xenia and Rudi, Stefan and Petkov, Valeri and Hoell, Armin and Strasser, Peter and TU Berlin) and Twente)},
abstractNote = {When exposed to corrosive anodic electrochemical environments, Pt alloy nanoparticles (NPs) undergo selective dissolution of the less noble component, resulting in catalytically active bimetallic Pt-rich core–shell structures. Structural evolution of PtNi6 and PtNi3 NP catalysts during their electrochemical activation and catalysis was studied by in situ anomalous small-angle X-ray scattering to obtain insight in element-specific particle size evolution and time-resolved insight in the intraparticle structure evolution. Ex situ high-energy X-ray diffraction coupled with pair distribution function analysis was employed to obtain detailed information on the atomic-scale ordering, particle phases, structural coherence lengths, and particle segregation. Our studies reveal a spontaneous electrochemically induced formation of PtNi particles of ordered Au3Cu-type alloy structures from disordered alloy phases (solid solutions) concomitant with surface Ni dissolution, which is coupled to spontaneous residual Ni metal segregation during the activation of PtNi6. Pt-enriched core–shell structures were not formed using the studied Ni-rich nanoparticle precursors. In contrast, disordered PtNi3 alloy nanoparticles lose Ni more rapidly, forming Pt-enriched core–shell structures with superior catalytic activity. Our X-ray scattering results are confirmed by STEM/EELS results on similar nanoparticles.},
doi = {10.1021/nn402406k},
journal = {ACS Nano},
issn = {1936-0851},
number = (7) ; 07, 2013,
volume = 7,
place = {United States},
year = {2013},
month = {10}
}