Surface sensitivity in lithium-doping of MgO

A density functional theory study with correction for on-site coulomb interactions

David O. Scanion, Aron Walsh, Benjamin J. Morgan, Michael Nolan, Joanne Fearon, Graeme W. Watson

Research output: Contribution to journalArticle

83 Citations (Scopus)

Abstract

Catalytic conversion of methane to higher hydrocarbons takes place on lithium-doped MgO. To date, investigations of the Li-doping process have been confined to the bulk and the (100) surface. In this paper, we describe an investigation of the surface dependence of Li-doping of MgO through an in-depth study of the (100), (110), and (111) low index surfaces using density functional theory with correction for on-site Coulomb interactions (DFT+U). Three competing defect configurations were investigated on each of the surfaces; substitution of Li for Mg with the formation of a compensating oxygen hole state, substitution of Li for Mg with the addition of a Li surface interstitial and the clustering of two Li ions with the formation of a neutral [Li′Mg V**OLi′Mg] oxygen vacancy. Our results demonstrate that the energetics associated with the Li-doping of MgO are strongly surface dependent. On the (100) surface, there is an energy cost associated with Li-doping, whereas on the (110) and (111) surfaces Li-doping is energetically favored. The implications of the results for the catalytic activity of the different surface terminations of MgO are discussed.

Original languageEnglish
Pages (from-to)7971-7979
Number of pages9
JournalJournal of Physical Chemistry C
Volume111
Issue number22
DOIs
Publication statusPublished - 2007 Jun 7

Fingerprint

Coulomb interactions
Lithium
Density functional theory
lithium
Doping (additives)
density functional theory
interactions
Substitution reactions
substitutes
Methane
oxygen
Oxygen vacancies
Hydrocarbons
Discrete Fourier transforms
catalytic activity
Catalyst activity
interstitials
methane
hydrocarbons
Ions

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Energy(all)
  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films

Cite this

Scanion, David O. ; Walsh, Aron ; Morgan, Benjamin J. ; Nolan, Michael ; Fearon, Joanne ; Watson, Graeme W. / Surface sensitivity in lithium-doping of MgO : A density functional theory study with correction for on-site coulomb interactions. In: Journal of Physical Chemistry C. 2007 ; Vol. 111, No. 22. pp. 7971-7979.
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Surface sensitivity in lithium-doping of MgO : A density functional theory study with correction for on-site coulomb interactions. / Scanion, David O.; Walsh, Aron; Morgan, Benjamin J.; Nolan, Michael; Fearon, Joanne; Watson, Graeme W.

In: Journal of Physical Chemistry C, Vol. 111, No. 22, 07.06.2007, p. 7971-7979.

Research output: Contribution to journalArticle

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