A DFT study on carbon monoxide adsorption onto hydroxylated α-Al 2O3(0001) surfaces

C. Rohmann, J. B. Metson, H. Idriss*

*Corresponding author for this work

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

The adsorption of CO onto the hydroxylated α-Al2O 3(0001) surface was studied using density functional theory (DFT). Dissociated adsorption of water was found to be stable, with an adsorption energy (Ea) of 1.62 eV at θwater = 0.75. The most stable hydroxylation form on the clean surface was found to be in the 1-2 dissociation configuration, where the OH group binds to a surface Al ion and the H ion binds to one of the three equivalent surface O ions. The adsorption energy of CO was found to be dependent on the degree of pre-hydroxylation of the surface as well as on the CO coverage. The highest adsorption energy of CO was found when θCO = 0.25 on a pre-hydroxylated surface with θwater = 0.25; Ea = 0.57 eV. The adsorption energy of CO decreased upon increasing the degree of pre-hydroxylation. The vibrational frequency of νCO was also computed and in all cases it was blue shifted with respect to gas-phase CO. The shift, Δν, decreased with increasing CO coverage but increased with increasing surface hydroxylation. A comparison with available experimental work is discussed.

Original languageEnglish
Pages (from-to)14287-14297
Number of pages11
JournalPhysical Chemistry Chemical Physics
Volume16
Issue number27
Early online date19 May 2014
DOIs
Publication statusPublished - 21 Jul 2014

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

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