不同晶型TiO_(2)催化臭氧氧化的性能研究

Catalytic properties of different crystalline TiO_(2)for ozone oxidation

采用溶胶-凝胶法,利用不同温度热处理制备不同晶体结构的TiO_(2)。以苯酚为目标污染物,研究了其催化臭氧氧化性能。结果表明,当催化剂质量相同时,锐钛矿型TiO_(2)因比表面积最大、表面羟基数量最多表现出最佳的臭氧催化活性;当对催化剂的表面积进行归一化时,表面羟基密度及活性氧含量随着TiO_(2)中金红石型含量的增大而增加,这表明金红石型的暴露面具有比锐钛矿型更高的内在活性。

The nanocrystalline TiO_(2)with different crystal structures were prepared by sol-gel method with heat treatment at various temperatures.The phenol was employed as the target pollutant to evaluate the catalytic ozonation activity of the samples.The results showed that when the catalysts were of the same mass,the anatase-rich TiO_(2)materials exhibited the best ozone catalytic activity due to the largest specific surface area and the largest number of surface hydroxyls.When normalized with respect to the surface area of the catalysts,the surface hydroxyl density and reactive oxygen content increased with the increase of rutile type content of TiO_(2),indicating that the exposed facets of rutile possessed an intrinsic higher activity than that of the anatase.