Synthesis of SAPO-11 molecular sieve with DPA and/or DIPA as templates

SAPO-11 was synthesized in the system of Al₂O₃-P2O₅-SiO₂-R Amine as template)-H₂O with di-n-propylamine (DPA) or di-i-propylamine (DIPA) (Single template method) or their mixtures as templates (Dual-template method). The results showed that synthesis with dual-template can avoid the impure phases of SAPO-5 and SAPO-31 found in synthesis with single template method. The crystallinity of SAPO-11 is varied in a wave form with the variation of template composition by using dual-template method. When w(DPA)=40% or 60%, maximum values of product relative crystallinity appeared. When w(DPA)=33% or 45%, minimum values were obtained. The tendency of relative crystallinity was not significantly affected by crystallization temperature, but varied with the gel n(SiO₂)/n(Al₂O₃) ratio.