Development of a simple aqueous solution based chemical method for synthesis of mesoporous gamma-alumina powders with disordered pore structure

Abstract

A technically simple chemical method for the synthesis of mesoporous gamma-alumina has been reported. Mesoporous gamma-aluminas with different pore structure and surface area were synthesized by using aluminium nitrate as a source of aluminum. Supramolecular liquid crystalline phase of acid soap template synthesized via reaction of different carboxylic acids (stearic acid, oliec acid and lactic acid) with excess of triethanolamine (TEA) acts as a structure directing agent and water was used as solvent. Precursors were calcined at 550 A degrees C in air for 2 h to obtain mesoporous alumina powders. Synthesized gamma-alumina powders were characterized by using thermogravimetric analysis, X-ray diffraction, high resolution transmission electron microscope and N(2) adsorption-desorption surface area and pore size analyzer. Pore size and ordering of pores were influenced by the chain length of carboxylic acids. Surface area of synthesized alumina powders varied from 214 to 376 m(2)/g and average pore diameter from 3.3 to 6.5 nm depending upon the chain length of the carboxylic acid.