Sol-gel-derived mesoporous gamma-alumina granules

Synthesis of stable boehmite sols and structural properties of the sol-gel- derived gamma-alumina using alkoxides, commercial boehmite powders, and alu minum chloride were studied for cost-effective preparation of high quality gamma-alumina granules. Stable boehmite sols could be prepared from aluminu m butoxide, aluminum isopropoxide, and commercial boehmite powders but not from aluminum chloride. The stable sol-derived gamma-alumina has large surf ace area and nanopore size with uniform pore size distributions. Mesoporous spherical gamma-alumina granules were prepared by an oil-drop process from aluminum butoxide, aluminum isopropoxide and a commercial boehmite powder under specific conditions. The sol-gel-derived gamma-alumina granules are b etter than the commercial gamma-alumina granules in terms of the pore struc ture and mechanical strength. The successful synthesis of gamma-alumina gra nules by the sol-gel method from the commercial boehmite powder provides a basis for large-scale, cost-effective production of the high quality gamma- alumina granules for use as sorbents or catalysts in industrial processes. (C) 1999 Elsevier Science B.V. All rights reserved.