Preformed zeolite precursor route for synthesis of mesoporous X zeolite

Mesoporous NaX zeolites (Meso-NaXs) have been successfully synthesized by a combination of preformed FAU (Faujasite) zeolite precursors and organic templates of cationic polymer (polydiallyldimethylammonium chloride, PDADMAC) and spirulina (SP). Characterization of Meso-NaXs by scanning electron micrographs (SEMs) indicates the existence of mesopores with sizes of 4–50 nm. Furthermore, nitrogen adsorption–desorption isotherms of Meso-NaXs exhibit not only adsorption at low relative pressure (P/P0 < 0.02) but also hysteresis loops at high relative pressure (P/P0 = 0.4–1.0). Additionally, the calcium ion-exchange rate of these mesoporous NaX zeolites is higher than that of conventional NaX zeolite, which would be very helpful for industrial application of NaX zeolite as a highly effective adsorbent and ion-exchanger.