Zeolites are microporous aluminosilicates crystalline materials with enclosed cages and channels of molecular size. With narrow pore size distribution and enclosed catalytic active sites, zeolites find wide applications in catalysis, separation and sensing. Colloidal nanozeolites, compared with conventional micron sized zeolites, have large external surface area (&gt; 100 m<sup>2</sup>/g) and short diffusion path (&lt; 20 nm), which in principle improves both efficiency and selectivity in catalysis. To synthesize colloidal nanozeolite particles with narrow particle size distribution, clear-solution synthesis method is used, which requires long synthesis time and has low yield. Microwave heating generally has advantages of uniform heating, increased crystallization kinetics and enhanced dissolution of precursor gel. Directly applying microwave heating to clear solution synthesis composition of nanozeolite Y results in the formation of polymorphs of zeolite Y and A.<br/>            In this study, clear solution synthesis with a single Al and Si composition that produces both zeolite Y and A polymorphs with microwave heating are studied with electron microscopy. The differences in nuclei structure between zeolite topologies are evaluated. Polymorphism formation mechanism and kinetics are studied. Understanding of zeolite crystal polymorphism formation mechanism will direct the rational tuning of synthesis conditions to control crystal polymorphism in material synthesis and explore new zeolite frameworks.

Microwave synthesis of colloidal nanozeolite and polymorphism mechanism

251st National Meeting (2016)

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