Block copolymer templating syntheses of mesoporous metal oxides with largeordering lengths and semicrystalline framework

A simple and general procedure has been developed fbr the syntheses of orde red large-pore (up to 14 nm) mesoporous metal oxides, including TiO2, ZrO2, Nb2O5, Ta2O5, Al2O3, SiO2, SnO2, WO3, HfO2, and mixed oxides SiAlOy, Al2Ti Oy, ZrTiOy, SiTiOy, ZrW2Oy. Amphiphilic poly(alkylene oxide) block copolyme rs were used as structure-directing agents in nonaqueous solutions for orga nizing the network-forming metal oxide species. Inorganic salts, rather tha n alkoxides or organic metal complexes, were used as soluble and hydrolyzab le precursors to the polymerized metal oxide framework. These thermally sta ble mesoporous oxides have robust inorganic frameworks and thick channel wa lls, within which high densities of nanocrystallites can be nucleated. Thes e novel mesoporous metal oxides are believed to be formed through a mechani sm that combines block copolymer self-assembly with alkylene oxide complexa tion of the inorganic metal species.