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Title: Strain effect on the adsorption, diffusion, and molecular dissociation of hydrogen on Mg (0001) surface

The adsorption, diffusion, and molecular dissociation of hydrogen on the biaxially strained Mg (0001) surface have been systematically investigated by the first principle calculations based on density functional theory. When the strain changes from the compressive to tensile state, the adsorption energy of H atom linearly increases while its diffusion barrier linearly decreases oppositely. The dissociation barrier of H{sub 2} molecule linearly reduces in the tensile strain region. Through the chemical bonding analysis including the charge density difference, the projected density of states and the Mulliken population, the mechanism of the strain effect on the adsorption of H atom and the dissociation of H{sub 2} molecule has been elucidated by an s-p charge transfer model. With the reduction of the orbital overlap between the surface Mg atoms upon the lattice expansion, the charge transfers from p to s states of Mg atoms, which enhances the hybridization of H s and Mg s orbitals. Therefore, the bonding interaction of H with Mg surface is strengthened and then the atomic diffusion and molecular dissociation barriers of hydrogen decrease accordingly. Our works will be helpful to understand and to estimate the influence of the lattice deformation on the performance of Mg-containing hydrogen storagemore » materials.« less
Authors:
; ; ;  [1] ;  [1] ;  [2] ; ; ;  [1] ;  [3]
  1. Ames Laboratory, USDOE, Ames, Iowa 50011 (United States)
  2. (China)
  3. (United States)
Publication Date:
OSTI Identifier:
22253847
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 139; Journal Issue: 22; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ADSORPTION; CHARGE DENSITY; DEFORMATION; DENSITY; DENSITY FUNCTIONAL METHOD; DIFFUSION BARRIERS; DISSOCIATION; HYDROGEN; HYDROGEN STORAGE; INTERACTIONS; STRAINS; SURFACES