Unusual non-bulk properties in nanoscale materials: Thermal metal-metal bond contraction of γ-alumina-supported Pt catalysts

Joo H. Kang; Laurent D. Menard; Ralph G. Nuzzo; Anatoly I. Frenkel

doi:10.1021/ja064207p

Unusual non-bulk properties in nanoscale materials: Thermal metal-metal bond contraction of γ-alumina-supported Pt catalysts

Joo H. Kang
, Laurent D. Menard
, Ralph G. Nuzzo
, Anatoly I. Frenkel

Materials Science and Engineering

University of Illinois at Urbana-Champaign

Research output: Contribution to journal › Article › peer-review

137 Scopus citations

Abstract

Variable-temperature X-ray absorption spectroscopy measurements of sub-nanometer Pt nanoparticles on a high-surface-area γ-alumina support reveal that the Pt-Pt bonds exhibit contraction upon heating [i.e., negative thermal expansion (NTE)]. Bare clusters under a He environment show an average linear expansion coefficient of -2.5 × 10^-5 K^-1 over the temperature range studied. Adsorption of hydrogen results in an overall bond relaxation and less dramatic Pt-Pt thermal bond-length contraction. From the temperature effect on bond length, disorder parameters, and the X-ray absorption near edge structure (XANES) spectra, temperature-dependent charge transfer between the support and the Pt clusters was concluded to be responsible for the observed behavior.

Original language	English
Pages (from-to)	12068-12069
Number of pages	2
Journal	Journal of the American Chemical Society
Volume	128
Issue number	37
DOIs	https://doi.org/10.1021/ja064207p
State	Published - Sep 20 2006

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title = "Unusual non-bulk properties in nanoscale materials: Thermal metal-metal bond contraction of γ-alumina-supported Pt catalysts",

abstract = "Variable-temperature X-ray absorption spectroscopy measurements of sub-nanometer Pt nanoparticles on a high-surface-area γ-alumina support reveal that the Pt-Pt bonds exhibit contraction upon heating [i.e., negative thermal expansion (NTE)]. Bare clusters under a He environment show an average linear expansion coefficient of -2.5 × 10-5 K-1 over the temperature range studied. Adsorption of hydrogen results in an overall bond relaxation and less dramatic Pt-Pt thermal bond-length contraction. From the temperature effect on bond length, disorder parameters, and the X-ray absorption near edge structure (XANES) spectra, temperature-dependent charge transfer between the support and the Pt clusters was concluded to be responsible for the observed behavior.",

author = "Kang, \{Joo H.\} and Menard, \{Laurent D.\} and Nuzzo, \{Ralph G.\} and Frenkel, \{Anatoly I.\}",

year = "2006",

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T1 - Unusual non-bulk properties in nanoscale materials

T2 - Thermal metal-metal bond contraction of γ-alumina-supported Pt catalysts

AU - Kang, Joo H.

AU - Menard, Laurent D.

AU - Nuzzo, Ralph G.

AU - Frenkel, Anatoly I.

PY - 2006/9/20

Y1 - 2006/9/20

N2 - Variable-temperature X-ray absorption spectroscopy measurements of sub-nanometer Pt nanoparticles on a high-surface-area γ-alumina support reveal that the Pt-Pt bonds exhibit contraction upon heating [i.e., negative thermal expansion (NTE)]. Bare clusters under a He environment show an average linear expansion coefficient of -2.5 × 10-5 K-1 over the temperature range studied. Adsorption of hydrogen results in an overall bond relaxation and less dramatic Pt-Pt thermal bond-length contraction. From the temperature effect on bond length, disorder parameters, and the X-ray absorption near edge structure (XANES) spectra, temperature-dependent charge transfer between the support and the Pt clusters was concluded to be responsible for the observed behavior.

AB - Variable-temperature X-ray absorption spectroscopy measurements of sub-nanometer Pt nanoparticles on a high-surface-area γ-alumina support reveal that the Pt-Pt bonds exhibit contraction upon heating [i.e., negative thermal expansion (NTE)]. Bare clusters under a He environment show an average linear expansion coefficient of -2.5 × 10-5 K-1 over the temperature range studied. Adsorption of hydrogen results in an overall bond relaxation and less dramatic Pt-Pt thermal bond-length contraction. From the temperature effect on bond length, disorder parameters, and the X-ray absorption near edge structure (XANES) spectra, temperature-dependent charge transfer between the support and the Pt clusters was concluded to be responsible for the observed behavior.

UR - https://www.scopus.com/pages/publications/33748805242

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DO - 10.1021/ja064207p

M3 - Article

AN - SCOPUS:33748805242

SN - 0002-7863

VL - 128

SP - 12068

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JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

IS - 37

ER -

Unusual non-bulk properties in nanoscale materials: Thermal metal-metal bond contraction of γ-alumina-supported Pt catalysts

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