Concentrated colloidal solution system for preparation of uniform Zeolite-Y nanocrystals and their gas adsorption properties

Abstract

Nanocrystalline Zeolite-Y having large internal and external surface area due to its nanometer scale crystals are applied for catalysis and separation processes. In this study, a novel approach for the preparation of uniform size Zeolite-Y nanocrystals from concentrated colloidal solution system is explored. The synthesis composition systems studied were concentrated solutions with high amount of organic template to give a large number of nuclei resulting in formation of uniform size nanocrystalline Zeolite-Y. The nanocrystalline Zeolite-Y of uniform particle sizes ca. 40 nm was successfully synthesized. The nanocrystalline Zeolite-Y synthesized in present study had excellent pore volume of ca. 0.91 cm3/g which is about three times than the pore volume obtained by conventional microcrystalline Zeolite-Y. A decrease in the organic template content resulted into the Zeolite-Y crystals of bigger size up to 60 nm along with some presence of Zeolite-A as impurity. The gas adsorption study of O2, N2, CO2, and CH4 were performed on these nanocrystalline zeolites and their gas separation properties were analysed. A strong CO2 interaction with the nanocrystalline Zeolite-Y was observed according to the adsorption model expressed by Toth equation. CO2/N2 selectivity and CO2/CH4 selectivity of ca. 300 were observed at lower relative pressure for the nanocrystalline Zeolite-Y which shows potential as promising material for application in CO2 separation of flue gas from thermal power plant and natural gas purification.