Effect of Synthesis Parameters on Phase Purity, Crystallinity and Particle Size of SAPO-34

An account is presented on investigation of the effects of synthesis parameters, i.e., reaction sources, silica to alumina ratio, acid molar ratio and crystallization conditions on the crystallinity, morphology and particle size of SAPO-34. The synthesis conditions were designed to produce small particles with narrow size range. The prepared samples were characterized by XRD and SEM techniques in order to evaluate the crystallinity, morphology and particle size. The XRD pattern was used to evaluate the crystallinity and phase purity. The phase purity of some samples, including SAPO-18 was determined by DIFFaX analysis from XRD data. The results were shown that formation of SAPO-18 is enhanced by increasing the acid content in the primary mixture. lower Si/Al ratio in a primary mixture resulted in production of AlPO's and SAPO-5 impurities. The type of template, silicon and aluminum source, acid concentration, agitation during crystallization, temperature and time of crystallization were found out as the significant parameters for controlling crystallinity and purity, particle size and morphology of the product.