Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας
Stathopoulos, V. N.
Manganese-based high surface area mesoporous and/or microporous mixed oxidic solids AMnO(x), where M = Al, La and Fe, have been prepared via controlled hydrolysis of a water sensitive tri-nuclear manganese complex [Mn3O(CH3COO)(6)(pyr)(3)]ClO4 in aquatic microenvironment (drops). The specific surface area of the obtained solids heated at 300 degreesC was found to be 711 m(2)/g for AlMnOx, 247 m(2)/g for LaMnOx and 199 m(2)/g for FeMnOx while the mean pore diameters were 3.6, 4.6, and 3.8 nm respectively. The surface composition of the solids was determined using XPS while their texture was checked using AFM. A mechanism of formation of the porous oxidic systems is proposed via hydrolytic attack of water molecules in the acetyl bridges of the complex followed by adsorption of A-cations on the Mn(OM), groups formed and diffusion limited aggregation (DLA) of the resulting clusters towards larger particles.