Layered titanosilicates for size- and pattern-controlled overgrowth of MFI zeolite

Size- and pattern-selective overgrowth of an MFI-type zeolite (silicalite-1) on the layered titanosilicates JDF-L1 (Jilin Davy Faraday-Layered solid 1, also known as Aveiro Manchester-1, AM-1) and AM-4 (Aveiro Manchester-4) is realized. The shell of MFI is grown as a closely packed monolayer of submicron cask-like particles following the surface contour of the core of plate-like particles of JDF-L1. The overgrowth of MFI on AM-4 carries the characteristics of heteroepitaxial interconnection. Isolated crystals (5-10 mu m) of MFI are closely embedded along various orientations to the plate-like particles of AM-4. The thermal behaviour of the interconnected materials was evaluated by in situ high-temperature powder X-ray diffraction. The realized heterochemical and heterostructural interconnections show that the surface of the layered titanosilicates can act as multi- and single-nucleation sites. This finding might be applied to other members of the family of tetrahedral-octahedral molecular sieves and may be important for the design of hierarchical catalysts and adsorbents with mixed properties.