Synthesis of Mesoporous Silica Nanospheres Promoted by Basic Amino Acids and their Catalytic Application

Discrete mesoporous silica nanospheres (MSNSs) with a narrow size distribution were prepared by a newly developed method, which is based on the emulsion system containing Si(OEt)(4) (TEOS), water, cationic surfactant, and basic amino acid under weakly basic conditions (pH 9-10). The average 20 nm sized discrete MSNSs have uniform craterlike mesopores about 3 nm in diameter. The size of the discrete spheres can be regulated in the range of 15-200 nm by, for example, changing the stirring rate in the synthesis stage. Furthermore, introduction of tetrahedrally coordinated Ti species onto the pore of MSNSs and their catalytic performance in epoxidation of different-sized alkenes, cyclohexene, cis-stilbene and caryophyllene were also demonstrated.