Sol-gel-derived mesoporous γ-alumina granules

Synthesis of stable boehmite sols and structural properties of the sol-gel-derived gamma-alumina using alkoxides, commercial boehmite powders, and aluminum chloride were studied for cost-effective preparation of high quality gamma-alumina granules. Stable boehmite sols could be prepared from aluminum butoxide, aluminum isopropoxide, and commercial boehmite powders but not from aluminum chloride. The stable sol-derived gamma-alumina has large surface 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 better than the commercial gamma-alumina granules in terms of the pore structure and mechanical strength. The successful synthesis of gamma-alumina granules 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.