| abstract |
A neutral templating route to mesoporous molecular sieves based on H-bonding and self-assembly between neutral primary amine or diamine surfactants (S°) and neutral inorganic precursors (I°) has been used to prepare hexagonal and lamellar mesoporous silicas with site isolated transition metal centers. This templating approach allows for the preparation of hexagonal or hexagonal-like mesoporous oxidation catalysts with large framework wall thickness of at least about 17 Å, small elementary particle size (<=400 Å), and unique combinations of framework-confined mesopores and textural mesopores while at the same time providing for facile recovery of the neutral template by simple solvent extraction. The templating of neutral metallosilicate precursors (I°) with neutral diamine surfactants (S°-S°) affords thermally stable pillared lamellar metallosilicates exhibiting complementary framework-confined microporosity and textural mesoporosity while at the same time also providing for template recovery by solvent extraction. In addition, a hexagonal transition metal-substituted catalysts, analogous to MCM-41, have been prepared using the mediated S+X-I+ templating pathway (Pathway 3) and mild reaction conditions. |