Journal ArticleDOI
Atom-Resolved Imaging of Dynamic Shape Changes in Supported Copper Nanocrystals
Poul L. Hansen,Jakob Birkedal Wagner,Stig Helveg,Jens R. Rostrup-Nielsen,Bjerne S. Clausen,Henrik Topsøe +5 more
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TLDR
In situ transmission electron microscopy is used to obtain atom-resolved images of copper nanocrystals on different supports, which are catalysts for methanol synthesis and hydrocarbon conversion processes for fuel cells.Abstract:
In situ transmission electron microscopy is used to obtain atom-resolved images of copper nanocrystals on different supports. These are catalysts for methanol synthesis and hydrocarbon conversion processes for fuel cells. The nanocrystals undergo dynamic reversible shape changes in response to changes in the gaseous environment. For zinc oxide-supported samples, the changes are caused both by adsorbate-induced changes in surface energies and by changes in the interfacial energy. For copper nanocrystals supported on silica, the support has negligible influence on the structure. Nanoparticle dynamics must be included in the description of catalytic and other properties of nanomaterials. In situ microscopy offers possibilities for obtaining the relevant atomic-scale insight.read more
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Interaction of CO, O, and S with metal nanoparticles on Au(111): A theoretical study
TL;DR: In this article, density functional theory and slab models are used to study the unusual behavior of Mo, Ni and Ru nanoparticles on a Au(111) substrate, and the calculations show that the metal particles energetically prefer to be embedded into the surface or form Au/metal particles/Au( 111) sandwich like structures.
Journal ArticleDOI
System for in situ UV-visible illumination of environmental transmission electron microscopy samples.
TL;DR: The nature of the design considerations, as well as the practical implementation and characterization of a solution are discussed, including a high brightness broadband light source with optical filters, a fiber to guide the light to the sample, and a mechanism for precisely aligning the fiber tip.
Journal ArticleDOI
Reshaping of Metal Nanoparticles Under Reaction Conditions.
TL;DR: The achieved quantitative agreement between the experimental observations and theoretical modelling demonstrate that the fundamental mechanism for the reshaping phenomenon is driven by anisotropically changed surface energies under gas adsorption, paving the way for the rational design of truly efficient nanocatalysts in real reactions.
Journal ArticleDOI
Critical review: Effects of complex interactions on structure and dynamics of supported metal catalysts
Anatoly I. Frenkel,Michael W. Cason,Annika Elsen,Ulrich Jung,Matthew W. Small,Ralph G. Nuzzo,Fernando D. Vila,John J. Rehr,Eric A. Stach,Judith C. Yang +9 more
TL;DR: In this paper, a new look at the problem of characterization of structural properties and reaction dynamics of supported metal catalysts is presented, in which different forms of structure and dynamics can be fully characterized by combining information obtained experimentally by in situ XAS and electron microscopy as well as theoretically via modeling.
Journal ArticleDOI
Combined TPRx, in situ GISAXS and GIXAS studies of model semiconductor-supported platinum catalysts in the hydrogenation of ethene
Sonja A. Wyrzgol,Susanne Schäfer,Sungsik Lee,Byeongdu Lee,Marcel Di Vece,Xuebing Li,Sönke Seifert,Randall E. Winans,Martin Stutzmann,Johannes A. Lercher,Stefan Vajda,Stefan Vajda +11 more
TL;DR: The preparation, characterization and catalytic reactivity of a GaN supported Pt catalyst in the hydrogenation of ethene are presented, highlighting the use of in situ characterization of the material properties during sample handling and catalysis by combining temperature programmed reaction with in situ grazing incidence small-angle X-ray scattering andX-ray absorption spectroscopy.
References
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