Effect of preparation process on the synthesis of composite molecular sieves by pre-loading raw method

The core/shell binary structure composite molecular sieves have been synthesized by loading raw materials method. The effects of types of aluminium source and preparation process were investigated. The synthesized samples were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM) and energy dispersive spectrometry(EDS). Using iso-propanol aluminum as the aluminium source, there is no SAPO-5 phase in short crystallization time; prolonging crystallization time increases the crystallinity of SAPO-5; the aging of the different reaction mixture at room temperature can cause a rapid formation of SAPO-5 sieve. The choice of the content of water in gel and mixing manners are dictated by types of aluminium source. Using pseudoboehmite as aluminium source, at the same pretreated temperature of coating phosphorus and preparation process, the sieve with higher degree of crystallinity was obtained.