Pressure-Dependent Effect of Hydrogen Adsorption on Structural and Electronic Properties of Pt/gamma-Al2O3 Nanoparticles

    Authors

    H. Mistry; F. Behafarid; S. R. Bare;B. R. Cuenya

    Comments

    Authors: contact us about adding a copy of your work at [email protected]

    Abbreviated Journal Title

    ChemCatChem

    Keywords

    hydrogen; nanoparticles; platinum; structure elucidation; X-ray; absorption spectroscopy; RAY-ABSORPTION SPECTROSCOPY; METAL-SUPPORT INTERFACE; PARTICLE-SIZE; PLATINUM; CATALYSTS; CHEMISORPTION; CLUSTERS; EXAFS; COVERAGE; STORAGE; Chemistry, Physical

    Abstract

    Understanding the interaction of hydrogen with subnanometer platinum nanoparticles (NPs) under industrially relevant conditions is of great importance to heterogeneous catalysis. In this work, we investigate the pressure-dependent changes in hydrogen coverage on size- and shape-selected Pt/-Al2O3 NPs by insitu X-ray absorption near-edge structure (XANES) analysis. Difference XANES calculations revealed an increase in the H/Pt ratio from 1.9 to 2.5 upon increasing the hydrogen pressure from 1 to 21bar at room temperature (1bar=100kPa). In addition, extended X-ray absorption fine structure measurements of the local geometrical structure showed changes in PtPt bond length and coordination number, revealing a morphological transformation in the NPs from a 2D to a 3D shape under increasing H-2 pressure at room temperature. Such shape evolution leads to a decrease in the NP-support contact area and is thus expected to affect the NP stability against coarsening.

    Journal Title

    Chemcatchem

    Volume

    6

    Issue/Number

    1

    Publication Date

    1-1-2014

    Document Type

    Article

    Language

    English

    First Page

    348

    Last Page

    352

    WOS Identifier

    WOS:000330636800044

    ISSN

    1867-3880

    Share

    COinS
     

    Accessibility Statement

    This item was created or digitized prior to April 24, 2027, or is a reproduction of legacy media created before that date. It is preserved in its original, unmodified state specifically for research, reference, or historical recordkeeping. In accordance with the ADA Title II Final Rule, the University Libraries provides accessible versions of archival materials upon request. To request an accommodation for this item, please submit an accessibility request form.