Effect of Organic Template, Transition Metal, and Ultrasonic Irradiation on the Synthesis of SAPO-34 Crystals as a Catalyst for MTO Process

In this study, SAPO-34 molecular sieves were synthesized by using both sonochemical-assisted hydrothermal and conventional hydrothermal heating and characterized by XRD and SEM techniques. Furthermore, to evaluate the effect of template on quality, performance and structure of final products, morpholine and tetraethyl ammonium hydroxide (TEAOH) were used separately as structure directing agent (SDA). Moreover, NiSAPO-34 molecular sieve has been synthesized and compared with SAPO-34 in order to determine the effect of transition metal ion on the physicochemical properties of samples. According to the results, it is found that template had an important effect on determining the shape, morphology and size distribution of the final products, metal incorporation into SAPO-34 framework increased crystallinity, and ultrasound irradiation led to a narrow particle size distribution.