کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7735881 | 1497963 | 2014 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Oxidation/reduction studies on nanoporous platinum films by electrical resistance measurements
ترجمه فارسی عنوان
مطالعات اکسیداسیون / کاهش بر روی فیلم های پلاتین نانو ذرات با اندازه گیری مقاومت الکتریکی
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
الکتروشیمی
چکیده انگلیسی
Mechanisms and kinetics of surface reactions in nanoporous platinum films were investigated. Nanoporous films of platinum of â¼250 nm thickness were deposited on glass slides by co-sputtering Pt and carbon followed by subsequently burning off carbon in air at 450 °C. Electrical resistance was measured in air and in 10% H2 + nitrogen at 80 °C as a function of time. The change in electrical resistance was extremely fast when switched to the H2 + N2 atmosphere. When switched to air, the film resistance increased with time at a much slower rate. The increase in resistance in air was attributed to the formation of Pt-oxide on the internal surfaces of the nanoporous films. The kinetics of oxidation was described by a model which includes two surface kinetic steps and a diffusional step. The use of nanoporous films makes it possible to investigate mechanisms and kinetics of surface reactions by ensuring a large surface to volume ratio. Oxide scale thickness at 80 °C in air after several hours of oxidation was only sub-monolayer. Oxide scale thickness after 3 h at 450 °C was about 1 nm. Implications of the results for proton exchange membrane fuel cell (PEMFC) Pt catalyst degradation are discussed.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Power Sources - Volume 269, 10 December 2014, Pages 621-631
Journal: Journal of Power Sources - Volume 269, 10 December 2014, Pages 621-631
نویسندگان
Liangzhu Zhu, Siddharth Kapoor, Quintin Parry, Ajay Nahata, Anil V. Virkar,