Title of article :
Chemisorption of isocyanate (NCO) on the Pd(1 0 0) surface at different coverages
Author/Authors :
Belelli، نويسنده , , Patricia G. and Branda، نويسنده , , Marيa M. and Garda، نويسنده , , Graciela R. and Ferullo، نويسنده , , Ricardo M. and Castellani، نويسنده , , Norberto J. Castellani، نويسنده ,
Issue Information :
هفته نامه با شماره پیاپی سال 2010
Pages :
9
From page :
442
To page :
450
Abstract :
The chemisorption of isocyanate (NCO) species on Pd(1 0 0) was studied within the density functional formalism (DFT) using a periodic slab model. The NCO was adsorbed on top, bridge and hollow sites of the metal surface at different coverages. At low coverages, the adsorption energies are in the range of −2.5/−3.0 eV, indicating an important adsorbate–substrate interaction for the three sites studied. The lateral repulsive interaction between neighboring NCO species is almost negligible or weak at lower and intermediate coverages, and very strong at complete monolayer. At low coverages, both bridge and hollow sites are energetically preferred; yet the bridge site becomes the only favoured site at intermediate and complete coverages. Work function and dipole moment calculations can be interpreted by an important charge transfer from the metal surface to NCO. Interestingly, while on hollow site the charge taken by NCO is essentially the same over all the range of coverage, an increasing depolarization is observed on bridge and top sites as the coverage increases. Symmetric and asymmetric NCO stretching modes were also calculated and compared with recent infrared spectroscopy measurements.
Keywords :
DFT , Periodic calculations , Work function , dipole moment , Adsorption
Journal title :
Surface Science
Serial Year :
2010
Journal title :
Surface Science
Record number :
1685661
Link To Document :
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