Characterization of Beta Zeolites by X-Ray Diffraction, Scanning Electron Microscope, and Refractive Index Techniques

Abstract

Lithium and sodium beta zeolites (Li-BEA, Na-BEA) by aqueous ion exchange at 65 °C and protonic beta zeolite (H-BEA) by deammoniation of NH₄-BEA at 540 °C were prepared. The crystallinity and morphology of all the samples of beta zeolite were examined by X-ray diffraction (XRD) and scanning electron microscopic (SEM) techniques.The hydrophobic and hydrophilic property was measured by refractive index technique. The measurements of the pH of the slurries 4% (g/mL) of parent beta zeolite (NH4-BEA),H-BEA, cation exchanging slurries and cation exchanged beta zeolites indicated the occurring of the process of ion-exchange. The lowest pH (3.2) was recorded for the ion-exchanging slurry of H-BEA by LiCl and NaCl solutions due to the formation of hydrochloric acid (HCl) during the cation- exchange process. Among the beta zeolites studied the proton form (H-BEA) showed that it was stable in the highly acidic reaction medium.