水合氧化锆的晶化方式对Pt/WO_3-ZrO_2异构化活性的影响

Effect of Crystallization of Hydrous Zirconia on the Isomerization Activity of Pt/WO_3-ZrO_2

采用不同方法制备了一系列具有一定晶相结构的水合ZrO2,考察了制备方法对水合ZrO2晶化方式及Pt/WO3-ZrO2催化剂催化正己烷异构化活性的影响.采用X射线衍射,Raman光谱和NH3-程序升温脱附对催化剂进行了表征.结果表明,水合ZrO2的晶化方式与制备时氧气的存在与否有关,也大大影响了催化剂的异构化活性.以无氧条件下制备的水合ZrO2为载体时,Pt/WO3-ZrO2催化剂具有较高的异构化活性,而以在空气气氛中制得的水合ZrO2为载体时,Pt/WO3-ZrO2几乎无异构化活性.

A series of crystalline hydrous zirconia supports were prepared by different methods. The preparation method affected the crystallization of the supports and catalytic activity of Pt/WO3-ZrO2 for n-hexane isomerization. The catalysts were characterized by X-ray diffraction, Raman spectroscopy, and NH3 temperature-programmed desorption. The crystallization of hydrous zirconia was affected by the ambience used in the synthesis. Crystalline hydrous zirconia prepared in the absence of oxygen led to a catalyst with high activity, and the case was the opposite when it was prepared in the presence of oxygen.