کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5426239 1395883 2007 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Density functional theory analysis of reactivity of PtxPdy alloy clusters
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Density functional theory analysis of reactivity of PtxPdy alloy clusters
چکیده انگلیسی

We investigate the reactivity of various PtxPdy combinations (with x + y = 10 and various x:y ratios) towards the adsorption of specific intermediates of the oxygen reduction, using the B3PW91 hybrid density functional theory. The reactivity is shown to be not only sensitive to the composition of the cluster, but also to the atomic distribution. The calculations indicate that two different ensembles: one ordered and one randomly mixed, with overall composition Pt3Pd7 are thermodynamically more favorable than pure Pt10 for the oxygen reduction reaction. The reasons for this behavior are clearly explained in terms of the atomic and electronic distribution, which makes the Pd atoms to act as electron donors both to Pt atoms and to the adsorbates, thus the reactivity of the Pd atoms in such environment becomes intermediate between Pt and Pd. Moreover, it is found that in a mixed Pt3Pd7 state the electronic distribution makes the average atom more similar to Pt than to Pd, whereas in an ordered Pt3Pd7 cluster, the average atom is more similar to Pd than to Pt.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Surface Science - Volume 601, Issue 1, 1 January 2007, Pages 165-171
نویسندگان
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