Nanoarchitectural approach for synthesis of highly crystalline zeolites with a low Si/Al ratio from natural clay nanotubes

A nanoarchitectural approach for synthesis of highly crystalline zeolites based on natural aluminosilicate nanotubes with adjustable silica to alumina ratio has been developed. A double template technique was proposed for synthesis of zeolite microcrystals with geometric morphology defined by the initial aluminosilicate nanotubes (halloysite). Remarkable and unique zeolite microcrystal shapes (submicron spheres, pompon-like systems and coffin-shaped prisms) possessing different internal structures (sodalite, analcime, mordenite, mordenite framework inverted) were obtained from halloysite by hydrothermal method. Halloysite Si/Al adjustments (acid etching, addition of extra silica or alumina) significantly affected crystalline structure and morphology of the obtained materials, while changing organic templates did not have a considerable effect.

Automated summary

A nanoarchitectural approach using natural Al2O3·2SiO2 nanotubes as templates has been developed for the synthesis of highly crystalline zeolites. By adjusting the Si/Al ratio and changing the organic templates of halloysite, the crystalline structure and morphology of the obtained materials can be controlled.