کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10244485 47690 2005 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The activity of the tetrahedral Au20 cluster: charging and impurity effects
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
The activity of the tetrahedral Au20 cluster: charging and impurity effects
چکیده انگلیسی
Several issues concerning the activity of the magical Au20 cluster are addressed with the help of Density Functional Theory (DFT) simulations. First, the cluster is found to be extremely robust against distortions when supported at an oxide (MgO) surface, keeping its tetrahedral shape. Second, the activity toward CO oxidation is studied as a function of the cluster charge state. Whereas the neutral cluster is found to be only moderately active, the anion becomes extremely active, because of the presence of a weakly bound unpaired electron. The attempt to induce cluster charging upon attachment to a charged surface F+-center was unsuccessful, with a cluster only slightly more active than the unsupported, neutral one. Finally, some initial steps towards the rational design of active catalysts were taken by the study of the effect of having different impurities. Promising results are obtained by the addition of an extra Na atom, which preferentially adsorbs inside the tetrahedron. Two competing isomers with an endohedral Na atom within a Au20 cage are found, and both of them are very active.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Catalysis - Volume 233, Issue 2, 25 July 2005, Pages 399-404
نویسندگان
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