Zirconium (IV) hydroxide, often called hydrous zirconia is an ill-defined material or family of materials variously described as ZrO2·nH2O and Zr(OH)4·nH2O. All are white solids with low solubility in water. These materials are widely employed in the preparation of solid acid catalysts.[2][3]
^ abChen, Fang Ren; Coudurier, Gisele; Joly, Jean Francois; Vedrine, Jacques C. (1993). "Superacid and catalytic properties of sulfated zirconia". Journal of Catalysis. 143 (2): 616–26. doi:10.1006/jcat.1993.1304.