Zeolite with trimodal porosity by desilication of zeolite nanocrystals aggregate

Zeolite with trimodal porosity can be synthesized by desilication of zeolite nanocrystal aggregate. In the desilication process, the originally existed intercrystalline mesopores of zeolite nanocrystal aggregate were enlarged into large mesopore, and the new small intracrystalline mesopore channel was created, thus the Zeolite with trimodal porosity was formed. The structure of resulted zeolite, both on aggregate and mesopore level can be fine tuned by the desilication degree.

The Si from the edges and boundary of nanocrystals was first removed resulted the surface roughness and enlarges of the originally existed intercrystalline mesopores. As the degree of alkali-treatment increasing, the Si species inside zeolite nanocrystals was also removed, leading to further enlarges the intercrystalline mesopores and the formation of small intracrystalline mesopores. In case the alkali-treatment is serve enough to completely dissolve the bridges between zeolite nanocrystals, zeolite nanocrystals were exfoliated from the aggregate.Figure optionsDownload as PowerPoint slideHighlights
► Zeolite with trimodal porosity by desilication of zeolite nanocrystals aggregate.
► The original intercrystalline mesopores were enlarged into large mesopore.
► The new intracrystalline mesopores were created as the inside Si extracted out.
► The aggregate structure, crystallinity and acidity of parent zeolite remained.
► Desilication is start on the edges then in the inner part of zeolite.