갈리실리케이트(Ga-MFI)의 합성 및 ZSM-5와의 비교

Synthesis of Gallosilicate(Ga-MFI} and Its Comparison with ZSM-5

Ga-MFI was synthesized by a hydrothermal process at atmospheric pressure. The effect of mole ratios of reactants on crystallization was also investigated thoroughly. The characteristics of synthesized Ga-MFI was compared with ZSM-5. The synthesis of Ga-MFI was carried out with five different mole-compositions of underline{a}SiO_2-underline{b}Ga_2O_3-underline{c}Na_2O-underline{d}TPA_2o-underline{e}H_2O . The synthesized Ga-MFI and ZSM-5 were characterized by XRD and FT-IR. The inorganic cation (Na^+ ) and water played an important role in crystallinity and the organic cation (TPA^+ ) as a template played a great influence on yields. With the increase in the amount of Ga^{3+} , crystallization time was increased. With a fixed SiO_2/Ga_2O_3 ratio of 400, the optimum reaction condition was obtained at H_2O/SiO_2 =30{sim} 35, Na_2O/SiO_2 =0.5{sim} 0.6, and TPA_2O/Na_2O =1{sim} 1.25. In these cases, the crystallinity and yield were more than 95% and 90%, respectively. By comparing IR spectrum of Ga-MFI with those of ZSM-5 and silicalite, it was found that Ga-MFI showed a unique peak at 970 cm^{-1} , which may be used to identify Ga-MFI from ZSM-5 and silicalite.