W/Mo-Oxide Nanomaterials: Structure鈭扨roperty Relationships and Ammonia-Sensing Studies

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• 作者：Ying Zhou ; Kaibo Zheng ; Jan-Dierk Grunwaldt ; Thomas Fox ; Leilei Gu ; Xiaoliang Mo ; Guorong Chen ; Greta R. Patzke
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：February 3, 2011
• 年：2011
• 卷：115
• 期：4
• 页码：1134-1142
• 全文大小：442K
• 年卷期：v.115,no.4(February 3, 2011)
• ISSN：1932-7455

文摘

W/Mo-oxides of the hexagonal tungsten bronze (HTB) type have been investigated by X-ray absorption spectroscopy to obtain detailed insight into the substitution process of W by Mo that leads to mixed HTB frameworks. Both the morphology of the nanostructured W/Mo-HTBs as well as the oxidation state of Mo are significantly influenced through the incorporation of different alkali cations into the hexagonal channels of this open structure. A variety of complementary analytical methods, including TG, in situ and ex situ XRD, SEM, and solid-state NMR analyses, were applied to determine the thermal stability of the obtained W/Mo-HTB materials with respect to their alkali cation and NH₄⁺ contents. A strong correlation between composition and stability was found with the Rb-W/Mo-HTBs exhibiting the highest structural and morphological resistance among the series (up to 580 掳C). The NH₃-sensing properties of selected W/Mo-oxides in test atmospheres furthermore point to promising features of the Rb-stabilized hexagonal framework materials.