کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9684941 | 1456218 | 2005 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Changes in hydrogen permeability and surface state of Pd-Ag/ceramic composite membranes after thermal treatment
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
تصفیه و جداسازی
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
Changes in hydrogen permeability and surface state of a Pd-Ag/ceramic membrane have been investigated as a function of thermal treatment. The surface state is determined by X-ray photoelectron spectroscopy (XPS). The XPS data show a significant enrichment of the Ag alloying element and an accumulation of impurity atoms (C, S, Na, Cl, O) in the surface layer of an as-prepared membrane. The thermal treatment, conducted at 400 °C in air for 1 h, results in a decrease of the Pd/Ag ratio in the surface (from 1:3.4 to 1:2.9), and an obvious chemical shift (ca. 1.4 eV) of Pd 3d core level but no change in the Ag 3d level, indicating the Pd2+ state of PdO is formed. The thermal treatment does not change the surface states of impurities of Na, Cl and O. On the other hand, XPS signal of the oxidized sulfur, SO42â species, is found. It is noted that the carbon concentration is decreased dramatically (from 67 to 32 at.%) by decomposition of carbon, a new XPS peak (BE = 292.5 eV) of CO2 is clearly identified from a treated surface. After the thermal treatment, the hydrogen permeability of the membrane is increased by a factor of 2.5, such behavior can be mainly attributed to the removing of the carbon contaminate initially present in the surface.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Membrane Science - Volume 252, Issues 1â2, 15 April 2005, Pages 145-154
Journal: Journal of Membrane Science - Volume 252, Issues 1â2, 15 April 2005, Pages 145-154
نویسندگان
Li Yang, Zhengxi Zhang, Xuhui Gao, Yaju Guo, Baofeng Wang, Osamu Sakai, Hitoshi Sakai, Tomonori Takahashi,