Abstract: Micelles formed by cetyltrimethylammoniumchlorine (CTAC) and n-butanol were used as shape-directing templates to synthesize SAPO-11 molecular sieve microspheres by a microwave technique. Effects of CTAC concentration, time of crystallization, and dosage of HF were investigated. Properties of the products were characterized systematically by X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), thermal analysis (TG-DTA), electron diffraction spectroscopy (EDS) and N2 physisorption. When c(CTAC)+c(n-butanol)=0.180 mol·L-1, SAPO-11 molecular sieve microspheres with the preferred crystallinity were obtained. The crystallinity of the synthesized SAPO-11 molecular sieve microspheres was improved by prolonging the reaction time. The substitution of Si species and the crystallization of SAPO-11 molecular sieve microspheres were also improved by appropriate usage of HF. Using control experiments, the reaction mechanism for the crystallization of SAPO-11 molecular sieve microspheres as mediated by ionic micelles and using the microwave technique is proposed.

Key words: Micelle, SAPO-11 molecular sieve, Microsphere, Microwave synthesis