Crystallization of AlPO-11 Aluminophosphate Molecular Sieves Using Secondary Amines

The study investigated the effects of the concentration of secondary amines with various molecular weights (specifically, diethylamine, di-n-propylamine, diisopropylamine, and di-n-butylamine), which were used as templates, on the crystallization performance of AlPO4-11 molecular sieves. For this purpose, various analytical methods such as XRD, SEM, and N2 adsorption/desorption were employed. The template concentration (more specifically, the template/Al2O3 ratio) was shown to have a major effect on the phase composition of the crystallization products. However, for each template under study, a high-phase-purity AlPO4-11 could be synthesized only within a narrow range of template/Al2O3 ratios. The study demonstrated the effects of template type on the morphology and dispersion of AlPO4-11 molecular sieves.