Surface and catalytic properties of ZrO2

Zirconium oxide is characterized to be the only one metal oxide which possesses explicitly four chemical properties on the surface; acidic and basic properties and oxidizing and reducing properties. Intriguing and sometimes unique catalytic activities of zirconium oxide itself are discussed in connection with the surface properties. It is also pointed out that zirconium oxide is an interesting and useful catalyst support. Generation of super acidity on the addition of a small amount of sulfate ion to zirconium oxide is elucidated. The surface properties of binary oxides containing zirconium oxide are also characterized.