Effect of organic solvents on the thermal stability of porous silica-modified alumina powders prepared via one pot solvothermal synthesis

Mixture of aluminum isopropoxide (AIP) and tetraethyl orthosilicate (TEOS) with weight ratios of AIP/TEOS = 8 in various organic solvents was set in an autoclave and heated at 300 degreesC for 2 h. The fluid phase was removed at the supercritical temperature. The products were calcined in air to yield silica-modified aluminas. These silica-modified aluminas had different morphology that affected the surface area and thermal stabilities at high temperatures. The reactions of AIP and TEOS in l-butanol gave substantially the wrinkled sheets morphology having the higher thermal stability than the spherical particles obtained by reaction in toluene. (C) 2000 Elsevier Science S.A. All rights reserved.