کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1548751 | 997755 | 2012 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Microstructure and oxygen storage capacity of Sr-modified Pt/CeO2–ZrO2 catalysts Microstructure and oxygen storage capacity of Sr-modified Pt/CeO2–ZrO2 catalysts](/preview/png/1548751.png)
Strontium was introduced into CeO2–ZrO2 mixed oxides (CZ) by doping and impregnation methods, and then Pt was impregnated on the Sr-modified CZ to obtain the catalysts. X-ray diffraction (XRD), X-photon spectra (XPS), high-resolution transmission electronic microscopy (HRTEM) and H2 temperature programmed reduction (TPR) were carried out to characterize the micro-structure and reducibility of catalysts. The oxygen storage capacity (OSC) was evaluated with CO serving as probe gas. The results showed that the incorporation of Sr2+ in the lattice of CZ could promote the OSC properties by increasing the structure defects and enhancing the diffusion rate of oxygen from bulk to surface. For the Sr-impregnated sample, the strong metal–support interaction (SMSI) between Pt and CZ was interrupted, since Sr covered partial surface Ce species. Such interruption retarded the back-spillover effect occurring at the Pt/Ce interface at low temperature, resulting in the loss of OSC. Meanwhile, it was found that a part of impregnated Sr2+ could partially diffuse from the surface to the inner atomic layers of CZ and partially incorporated in the lattice during the calcination. The OSC performance of Sr-impregnated sample therefore climbed remarkably with the rise of temperature.
Journal: Progress in Natural Science: Materials International - Volume 22, Issue 1, February 2012, Pages 7–14