钛锆复合氧化物载体的制备、物化性质及在催化反应中的应用

 TiO2-ZrO2复合氧化物具有比TiO2和ZrO2更高的比表面积、更好的热稳定性和更强的表面酸碱性,作为催化剂载体已引起很大的研究兴趣并得到了重要的应用. 本文主要介绍了TiO2-ZrO2复合氧化物载体的制备方法以及织构、结构和表面酸碱性等物化性质,并对其在催化反应中的应用进行了综述.

Preparation and Physico chemical Properties of TitaniumZirconium Mixed Oxide and Its Application as a Catalyst Support

It is well known that the nature of supports play an important role in the catalytic performance of supported catalysts. The TiO 2-ZrO 2 binary oxide displays higher specific surface area and thermal stability than its individual TiO 2 and ZrO 2 components. Furthermore, the mixed oxide is found to exhibit high surface acidity by a charge imbalance based on the generation of Ti-O-Zr bonding. Thus, the combined TiO 2-ZrO 2 mixed oxide has attracted much attention recently as a catalyst support for various applications. In this paper, the preparation methods, and textural, structural and surface acidic and basic properties of TiO 2-ZrO 2 are introduced. The TiO 2-ZrO 2 mixed oxide is usually prepared by calcination of metal hydroxide, which can be prepared by co-precipitation, homogeneous precipitation and sol-gel methods. The XRD analysis reveals that the crystallization of the binary oxide is inhibited by the interaction of TiO 2 and ZrO 2, which explains the significant changes in its surface area, acidity and basicity. The preparation methods and conditions such as molar ratio of Ti/Zr and calcination temperature for TiO 2-ZrO 2 affect its physical and chemical properties. In the case of TiO 2-ZrO 2-supported catalysts, such changes can affect the electronic and geometric properties of active phases obtained and consequently the catalytic performance of the catalysts. Examples of the application of TiO 2-ZrO 2 as a catalyst support for various reactions such as selective catalytic reduction of NO x, hydrogenation, hydrodesulfurization and vapor phase Beckmann rearrangement of cyclohexanone oxime are reviewed and 85 references are cited.