|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|178640||459310||2016||4 صفحه PDF||سفارش دهید||دانلود رایگان|
• Pt-skin/Pt–Co(111) single crystals exhibited extremely high ORR activity, jk.
• Pt-skin had atomically flat terraces with the same atomic arrangement as the bulk.
• Maximum jk at Pt-skin/Pt0.75Co0.25 was 25 times higher than that at pure Pt(111).
• The enhanced ORR activity cannot be explained by decreased OH poisoning.
• An alternate ORR model must be developed to explain all of the present results.
The kinetically controlled area-specific activities, jk, for the oxygen reduction reaction (ORR) were evaluated at well-defined Pt-skin/Pt100 − xCox(111) single crystal electrodes as a function of Co content by use of the rotating disk electrode method. The Pt-skin layer formed by annealing under a pure H2 atmosphere was clarified to consist of atomically flat terraces with the same atomic arrangement as the underlying crystal. At 25 atom%-Co, the jk value reached a maximum as high as 3.0 mA cm− 2 at 0.9 V vs. RHE, which is ca. 25 times larger than that on pure Pt(111). Such an enhanced ORR activity of Pt-skin/Pt–Co(111) electrodes cannot be explained on the basis of decreased OH poisoning, because the surface oxidation charge densities measured at 0.9 V in N2-purged solution were nearly constant.
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Journal: Electrochemistry Communications - Volume 67, June 2016, Pages 47–50