Abstract: Zirconium-doped pseudoboehmite with the following properties: zirconium content of 0.5 to 10 mol % relative to Al water content of 20 to 35 weight percent total of the anionic impurities less than 0.5 weight percent. It is synthesized by a process wherein zirconium salt is added in calculated quantity to an aqueous aluminum sulfate solution, the resulting mixture is fed simultaneously with a sodium aluminate liquor into a water pool having a temperature of 50.degree. to 100.degree. C., thereby precipitating zirconium-doped alumina gel while a pH of 3.5 to 8 is maintained, the pH of the suspension is adjusted after addition of the aluminum sulfate solution to 8.5 to 10.5 by further addition of sodium aluminate liquor, the suspension is digested if necessary at the pH of 8.5 to 10.5 and the temperature of 50.degree. to 100.degree. C. for a period of up to 24 hours, the formed pseudoboehmite crystals are filtered off, the filter cake is redispersed with water and the suspension is sprayed-dried.

Abstract: Zirconium-doped pseudoboehmite with the following properties: zirconium content of 0.5 to 10 mol % relative to Al water content of 20 to 35 weight percent total of the anionic impurities less than 0.5 weight percent. It is synthesized by a process wherein zirconium salt is added in calculated quantity to an aqueous aluminum sulfate solution, the resulting mixture is fed simultaneously with a sodium aluminate liquor into a water pool having a temperature of 50.degree. to 100.degree. C., thereby precipitating zirconium-doped alumina gel while a pH of 3.5 to 8 is maintained, the pH of the suspension is adjusted after addition of the aluminum sulfate solution to 8.5 to 10.5 by further addition of sodium aluminate liquor, the suspension is digested if necessary at the pH of 8.5 to 10.5 and the temperature of 50.degree. to 100.degree. C. for a period of up to 24 hours, the formed pseudoboehmite crystals are filtered off, the filter cake is redispersed with water and the suspension is sprayed-dried.