Direct synthesis of core–shell MFI zeolites with spatially tapered trimodal mesopores via controlled orthogonal self-assembly

Abstract

Manipulating pore hierarchy in porous materials is an attractive, yet difficult challenge in crystalline zeolites. Here, we report core–shell MFI zeolites having trimodal mesopores with size gradually decreasing from the surface to the core, synthesized through a one-pot approach via controlled orthogonal self-assembly. The novel spatially resolved mesopore structures are ascribed to the nanoscale phase separation between mutually coupled interactions of organosilane supramolecular assembly and zeolite framework ordering. The highly hierarchical zeolite architecture with tapered mesopore distribution allowed for spatially resolved adsorption of florescent molecules, improved catalytic performance in condensation reactions, and an enhanced nanoreactor for coupling reactions due to alleviated diffusion limitations. The successful synthesis of fine-tuned zeolites with larger mesopores gradually subdivided into smaller mesopores (hierarchy-type I) may open up possibilities for emergent new porous structures exhibiting a higher degree of hierarchies that are currently inaccessible to many crystalline oxide or related materials.