Transition metal–alumina/silica supermicroporous composites with tunable porosity

A novel class of alumina/silica–transition metal based materials has been synthesized via sol–gel method. The materials exhibit Type I adsorption/desorption isotherms with the pores mainly in the range 10–20 Å. The pore size, surface area and the pore volume are strongly correlated with the size of the alkylamine template employed. The versatile synthesis method allows for the control of the porosity of the materials via varying Al/Si ratios, transition metal content, the amount of water employed for the hydrolysis as well as thermal treatment. The materials were characterized by N2 physisorption, solid state NMR methods, TGA, magnetic measurements and TEM. The relationship between the transition metal and the alumina/silica matrix has been clarified by these studies.