Gas-phase photo-oxidations of organic compounds over different forms of zirconia

作者:Wu CY; Zhao XP; Ren YJ; Yue YH*; Hua WM; Cao Y; Tang Y; Gao Z
来源:Journal of Molecular Catalysis A: Chemical , 2005, 229(1-2): 233-239.
DOI:10.1016/j.molcata.2004.11.029

摘要

Nanosized zirconia powders with different phase structure and specific surface area were prepared by various methods and were used as catalysts for gas-phase photocatalytic oxidations of methanol and hexane. The phase structure of the samples was analyzed by X-ray diffraction and Raman spectroscopy. The photocatalytic activity of the amorphous zirconia synthesized in this experiment is much higher than that of the crystalline samples. The activity of hexane oxidation on ZrO2-0-110 reaches 25.6%, which is even higher than that of Degussa P25 (17.3%). Thermal gravimetric studies show that the high activity is due to the abundant surface hydroxyl groups on the catalysts. Sulfation of zirconia samples induces a decrease in the amount of surface hydroxyl groups and has a negative influence on the activity of the zirconia photocatalysts. The results of a 100 h test show that the activity of the synthesized amorphous zirconia catalyst is very stable.