Mesoporous Materials from Template-Free Vapor-Phase Reductive Leaching of Zn from Zn鈥揗鈥揙 Compounds (M = Nb, Mo, W)

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• 作者：Claudia Lermer ; Megan M. Butala ; Bethany R. Lettiere ; Ram Seshadri
• 刊名：Crystal Growth & Design
• 出版年：2014
• 出版时间：September 3, 2014
• 年：2014
• 卷：14
• 期：9
• 页码：4526-4530
• 全文大小：448K
• ISSN：1528-7505

文摘

Vapor-phase leaching of Zn and O from complex oxides was performed with the goal of creating mesoporous metal oxides with connected porosity. At elevated temperatures, complex Zn鈥揗鈥揙 oxides (M = Nb, Mo, W) can be reduced to yield textured product materials, including reduced M鈥揙 oxides, nitrides, and the metal. The nature of the product varies with temperature, time, reducing atmosphere, and the identity of the metal M. M = Nb results in the formation of porous NbO₂ without the need for extraneous templates or pore formers. The crystal chemistry of the starting Nb compound is found to influence the nature of the texturing or porosity of the final product. The evolution of morphology is also impacted by the starting Zn:Nb ratio. In the case of the Mo and W compounds, reductive leaching yields the metal or metal nitride (for M = Mo). Morphology change is also observed, and varies for each product phase. An additional interesting aspect of the process is that the reductive leaching occurs in stages, allowing intermediate Zn鈥揗鈥揙 compositions with reduced M to be stabilized. The evolution of morphology also appears to be dependent on the initial and final crystal structures.