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

Abstract

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 μm) 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.