کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
193141 | 459763 | 2007 | 8 صفحه PDF | دانلود رایگان |
A simple procedure is introduced to use periodic Density Functional Theory calculations to estimate trends in the thermodynamics of surface alloy dissolution in acidic media. With this approach, the dissolution potentials for solute metal atoms embedded in the surface layer of various host metals (referenced to the dissolution potential of the solute in its pure, metallic form) are calculated. Periodic trends in the calculated potentials are found to be related to trends in surface segregation energies of the various solute/host pairs. The effects of water splitting and concomitant hydroxyl adsorption on the dissolution potentials are also considered; these effects do not change the potentials for highly oxophilic solutes embedded in less active hosts, but they do decrease the dissolution potential for more inert solutes on oxophilic hosts. Finally, the dissolution of Pt “skin” layers from Pt3X (X = Fe, Co, and Ni) bulk alloys is analyzed; the Pt skins are found to be stabilized compared to pure Pt.
Journal: Electrochimica Acta - Volume 52, Issue 19, 25 May 2007, Pages 5829–5836