Does Halogen Adsorption Activate the Oxygen Atom on an Oxide Surface? I. A Study of Br 2 and HBr Adsorption on La 2 O 3 and La 2 O 3 Doped with Mg or Zr

TitleDoes Halogen Adsorption Activate the Oxygen Atom on an Oxide Surface? I. A Study of Br 2 and HBr Adsorption on La 2 O 3 and La 2 O 3 Doped with Mg or Zr
Publication TypeJournal Article
Year of Publication2012
AuthorsLi B, Metiu H
JournalJournal of Physical Chemistry C
Volume116
Issue6
Start Page4137
Pagination4137–4148
Date Published02/2012
ISSN1932-7447
KeywordsAFOSR, CNSI, CSC, DOE, Metiu
Abstract

Experiments suggest that adsorbing halogen atoms on an oxide surface can improve its catalytic properties. We use density functional theory to examine the dissociative adsorption of Br2 and of HBr on La2O3(001) and on La2O3(001) doped with Mg or Zr. We find that the presence of Br on the surface makes it much easier to make oxygen vacancies. In addition, there is a very strong interaction between the fragments made by the dissociative adsorption of Br2 or HBr: the presence of one fragment increases substantially the binding energy of the other one. We propose that this is a general behavior whenever one fragment is a Lewis acid and the other is a Lewis base, while the oxide is neither. Experiments suggest that adsorbing halogen atoms on an oxide surface can improve its catalytic properties. We use density functional theory to examine the dissociative adsorption of Br2 and of HBr on La2O3(001) and on La2O3(001) doped with Mg or Zr. We find that the presence of Br on the surface makes it much easier to make oxygen vacancies. In addition, there is a very strong interaction between the fragments made by the dissociative adsorption of Br2 or HBr: the presence of one fragment increases substantially the binding energy of the other one. We propose that this is a general behavior whenever one fragment is a Lewis acid and the other is a Lewis base, while the oxide is neither.

URLhttp://dx.doi.org/10.1021/jp209857s
DOI10.1021/jp209857s
Grant: 
CSC