Investigation of hydrothermal synthesis parameters on characteristics of T type zeolite crystal structure

Hydrothermal synthesis of zeolite T in aqueous alkaline solutions without using templates was investigated. Zeolite T crystals were prepared via hydrothermal synthesis using milk-like aluminosilicate gel with a composition of aSiO2:bAl2O3:cNa2O:dK2O:xH2O. The effects of molar compositions including silicon module (nRM = a/b) and relative alkalinity (α = OH/SiO2), and crystallization conditions including crystallization temperature (T) and time (t) on the yield of T-type crystals were investigated. This research work examines changes in the yield of crystalline zeolite phases by varying the gel composition parameters (nRM = 20–25, and α = 0.71–0.82) and crystallization process temperature and time (T = 100°−140 °C, t = 120–216 h), while keeping constant the parameters [OH] = 2.77 m, URM(Na/Na + K) = 0.75, stirring time = 24 h , stirring temperature = 30 °C, and drying temperature = 100 °C. The crystal species of zeolite T were characterized by XRD (X-ray diffraction) and SEM (Scanning Electron Microscope).

The effects of gel composition and crystallization condition parameters on Zeolite T crystals synthesized by the hydrothermal method were investigated. The intergrowth of W, T and L coexisting type zeolites were examined by X-ray diffraction (XRD). The morphology and structure of T-type zeolite crystals examined by Scanning Electron Microscopy (SEM) revealed very high crystallinity with a mean crystal size of around 6.7 μm.Figure optionsDownload full-size imageDownload as PowerPoint slide