کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6615514 | 459622 | 2013 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
An identical-location transmission electron microscopy study on the degradation of Pt/C nanoparticles under oxidizing, reducing and neutral atmosphere
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موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
مهندسی شیمی (عمومی)
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چکیده انگلیسی
This study shows that the predominant degradation mechanism of Pt/Vulcan XC72 electrocatalysts strongly depends on the nature of the gas atmosphere and of the upper potential limit used in accelerated stress tests (ASTs). The morphological changes of Pt/Vulcan XC72 nanoparticles were studied by identical location transmission electron microscopy (IL-TEM), following accelerated stress tests in different potential ranges and under various gas atmospheres. X-ray photoelectron spectroscopy was used to probe changes in carbon surface chemistry. Whereas minor changes were detected under neutral atmosphere (Ar) and low potential limit conditions (0.05Â <Â EÂ <Â 0.50Â V vs. RHE), the migration/aggregation of Pt nanocrystallites was strongly accelerated in the presence of a reducing atmosphere, such as CO. Carbon corrosion and Pt nanoparticle detachment were more frequently observed under oxidizing atmosphere (O2). With an increase of the upper potential limit to 1.23Â V vs. RHE, the trends observed previously were maintained but 3D Ostwald ripening strongly overlapped with the three other degradation mechanisms, precluding any identification of the dominant mechanism.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Electrochimica Acta - Volume 110, 1 November 2013, Pages 273-281
Journal: Electrochimica Acta - Volume 110, 1 November 2013, Pages 273-281
نویسندگان
L. Dubau, L. Castanheira, G. Berthomé, F. Maillard,