Role of Ti–O–Zr Bonding in TiO2–ZrO2 Catalyst for Dehydrogenation of Ethylbenzene

A relationship between acid amounts over TiO2–ZrO2 catalysts and their activities for nonoxidative dehydrogenation of ethyl benzene to styrene was examined. The catalysts were prepared by two different methods; one is simultaneous hydrolysis of Ti and Zr mixed alkoxides solution and the other is physical mixing of pure TiO2 and ZrO2. The former consists of fine TiO2 and ZrO2 particles and is expected a lot of Ti–O–Zr bonding between the fine particles, while the latter is composed of large particles and less amounts of Ti–O–Zr bonding might be expected. Although the Ti–O–Zr bonding has been considered to generate a new acid site and to enhance the rate of dehydrogenation of ethylbenzene, the acid amounts and the rates observed on unit surface areas of both catalysts were not significantly different. On the basis of these results, the role of Ti–O–Zr bondig in TiO2–ZrO2 catalyst for dehydrogenation of ethylbenzene is discussed.