کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5424140 | 1507957 | 2010 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Unsaturated hydrocarbons adsorbed on low coordinated Pd surface: A periodic DFT study
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Unsaturated hydrocarbons adsorbed on low coordinated Pd surface: A periodic DFT study Unsaturated hydrocarbons adsorbed on low coordinated Pd surface: A periodic DFT study](/preview/png/5424140.png)
چکیده انگلیسی
In this work, the adsorption of several unsaturated hydrocarbon molecules on a stepped Pd(4Â 2Â 2) surface was studied. Using a periodic method based on the Density Functional Theory (DFT) formalism, different adsorption geometries for ethylene, three butene isomers (cis/trans-2-butene and 1-butene), acetylene and 2-butyne were investigated. The results were compared with those obtained for a free defect surface as Pd(1Â 1Â 1). The 1-butene is more stable on the free defect surface than on Pd(4Â 2Â 2). On the stepped surface, the olefins adsorb tilted towards the step and increases, in almost all the cases, the magnitude of the adsorption energy. Conversely, the 3-fold site is the most stable for the alkynes adsorption on the stepped surface, as it was found on Pd(1Â 1Â 1). The analysis of the dipole moment change indicate a charge transfer from the double bond of the olefin to the metallic surface, being higher for the Pd(1Â 1Â 1) surface. In case of the alkynes, an important back-donation is produced. Except the alkynes and the 1-butene molecule, the results show the preference of ethylene and cis/trans-2-butene to be adsorbed on the stepped surface. These observations are related with experimental catalytic results.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Surface Science - Volume 604, Issues 3â4, 15 February 2010, Pages 386-395
Journal: Surface Science - Volume 604, Issues 3â4, 15 February 2010, Pages 386-395
نویسندگان
Patricia G. Belelli, Ricardo M. Ferullo, Norberto J. Castellani,