Synthesis and characterization of NaY zeolite from Bayat natural zeolite: Effect of pH on synthesis

Abstract

Herein, NaY zeolite was synthesized by a hydrothermal method via seeding using Bayat natural zeolite with a Si:Al ratio of 6.26, which comprised the silica and alumina sources as well as sodium alumínate as the additional alumina source. Poorly crystalline natural zeolite contains several impurities; thus, activation and purification are crucial for removing some impurities and widening the zeolite pores. Before synthesis, Bayat natural zeolite was subjected to dealumination to remove some alumina and fragmentation to break the zeolite framework into their monomers. In addition, the effect of pH on synthesis was investigated. NaY zeolite was characterized via X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy equipped with energy-dispersive X-ray spectroscopy (EDX). The XRD patterns revealed that a pH of 11-12 is typical for synthesizing NaY zeolite. Different FTIR spectra were observed for the raw, fragmented, and as-synthesized NaY. The EDX data revealed that NaY zeolite synthesized at pH values of 11-13 exhibits Si:Al ratios of 5.35, 3.72, and 2.96, respectively.