Synthesis of zeolite NaX using elephant grass (pennisetum purpureum) as a silica source and its characterization

Abstract

Zeolite NaX is a synthetic zeolite with faujasite framework that has large pores, which it is largely used as adsorbents. Zeolite NaX was synthesized using silica (SiO₂) which was extracted from elephant grass (Pennisetum purpureum). The silica was isolated from elephant grass using its ash with conventional ignition method, with NaOH as solvent. The extracted silica purity is 86.33%. Zeolite NaX was synthesized with 3.5 Na₂O : Al₂O₃ : 2.9 SiO₂ : 150 H₂O as molar ratio in hydrothermal condition at 90 °C for 15 hours. Synthesized zeolite was then characterized using FTIR to confirm the formation of zeolite based on chemical bonding that appears on the spectrum, XRD to confirm the framework structure of the formed zeolite, and SEM to obtain its morphology. Based on those analysis, it is known that the result of synthesis process is zeolite with NaX crystal structure and octahedral morphology with crystal sizes range 1-5 µm.