PREPARATION OF STABILIZED ALUMINA HAVING ENHANCED RESISTANCETO LOSS OF SURFACE AREA AT HIGH TEMPERATURES

摘要

2131795 9317968 PCTABS00025 A process for preparing stabilized alumina having increased surface area retention at high temperature in which a gel of a boehmite alumina which has been obtained by hydrothermally treating an aqueous mixture of a precursor beohmite alumina having a pH of from about 5 to about 9 for a period of time sufficient to convert the greater portion of the precursor boehmite alumina to a colloidal sol is subjected to working as, for example, by using a sufficient shearing force for a sufficient period of time to produce a worked boehmite alumina which has an increase in pore volume of at least about 30 percent and an increase of median pore radius of at least about 20 percent, a stabilizer being added to the boehmite alumina, the stabilizer being an oxide of a metal such as barium or a metal included in the lanthanide series of metals or a compound of such metals which converts to an oxide at elevated temperatures.