Synthesis, characterization and catalytic activity of amorphous Al,SiOx gels from weakly acidic aqueous solutions

Abstract

Al,SiO_xgels have been prepared by reaction of different inorganic aluminium compounds with silicic acid. Characterization by chemical analysis,²⁷Al MAS NMR spectroscopy and adsorption measurements shows that the gels obtained from a mixture (pH ca. 3) of basic aluminium chlorides and silicic acid in water are porous and contain tetrahedrally coordinated aluminium in the framework. IR spectroscopy and TPDA measurements confirm that Brønsted and Lewis acid sites are present in the gels. Finally, catalytic activity was found in hex-1-ene isomerization.