Engineering Dandelion-Like Hollow TS-1@SiO2: Structural Design and Oxidation Application

Inspired via the dandelion structure which has multi-dimensional channels facilitating the transport of fluids, bilayer TS-1@dandelion-SiO2 and hollow HTS@dandelion-SiO2 were successfully synthesized via an hydrothermal strategy including core TS-1 or HTS particles synthesis and an epitaxial growth of regular SiO2 shell. TS-1@dandelion-SiO2 or hollow HTS@dandelion-SiO2 possessed a ca. 300 nm core with ca. 100-200 nm of SiO2 shell with perpendicular channels, this hierarchical structure facilitated reactants/products transportation, and the structured SiO2 shell triggered the size of TS-1 or HTS and increased to similar to 800 nm, which was beneficial for nanosized crystals separation and recovery from the reaction system. Particularly, the epitaxial SiO2 shell increased Lewis acid sties on TS-1 and HTS external surface enhancing cyclohexene conversion. Further, the relationship between SiO2 shell morphology and catalytic activity was explored through the synthesis of HTS@inordinance-SiO2 with irregular SiO2 shell indicating the superiority of oriented channels originated from regular SiO2 shell. [GRAPHICS] .