BROWSE

Related Researcher

Author's Photo

Kwak, Ja Hun
Molecular Catalysis lab
Research Interests
  • Heterogeneous catalysis, molecular catalysis, ASlumima, zeolites

ITEM VIEW & DOWNLOAD

Understanding the nature of surface nitrates in BaO/gamma-Al2O3 NOx storage materials: A combined experimental and theoretical study

Cited 52 times inthomson ciCited 54 times inthomson ci
Title
Understanding the nature of surface nitrates in BaO/gamma-Al2O3 NOx storage materials: A combined experimental and theoretical study
Other Titles
Understanding the nature of surface nitrates in BaO/gamma-Al2O3 NOx storage materials: A combined experimental and theoretical study
Author
Kwak, JahunMei, DonghaiYi, Cheol-WooKim, Do HeuiPeden, Charles H. F.Allard, Lawrence F.Szanyi, Janos
Keywords
TOTAL-ENERGY CALCULATIONS; GAMMA-ALUMINA SURFACES; AUGMENTED-WAVE METHOD; MOLECULAR-DYNAMICS
Issue Date
2009-01
Publisher
ACADEMIC PRESS INC ELSEVIER SCIENCE
Citation
JOURNAL OF CATALYSIS, v.261, no.1, pp.17 - 22
Abstract
A combined experimental-theory approach was applied to unambiguously determine the nature of "surface nitrates" in BaO/gamma-Al2O3 NOx storage materials. High resolution scanning transmission electron microscopy images reveal that at a low BaO coverage of 2 wt% gamma-Al2O3 monomeric BaO units are present almost exclusively. These molecularly dispersed BaO units are concentrated on the (100) facets Of the alumina crystallites, while other facets remain practically BaO-free The results of the density functional theory calculations predicted adsorption geometries for the (BaO)(x) (x = 1 and 2) units. The energetically most favorable BaO monomer and dimer units anchor to pentacoordinate Al3+ sites on the (100) facets of gamma-Al2O3 in such geometries that maximize their interactions with the support surface. The calculated vibrational frequencies of the energetically most favorable nitrate species formed upon the interaction of NO2 with the monomeric and dimeric BaO units agree remarkably well with those observed experimentally by infrared spectroscopy and identified as "surface nitrates." Published by Elsevier Inc
URI
Go to Link
DOI
10.1016/j.jcat.2008.10.016
ISSN
0021-9517
Appears in Collections:
ECHE_Journal Papers
Files in This Item:
1-s2.0-S0021951708004028-main.pdf Download

find_unist can give you direct access to the published full text of this article. (UNISTARs only)

Show full item record

qrcode

  • mendeley

    citeulike

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

MENU