Investigation the Synthesis of Nano-SAPO-34 Catalyst Prepared by Different Templates for MTO Process

Abstract

In this paper, nine samples of SAPO-34 Nanocatalysts were synthesized, at three temperatures (170, 190, 210 °C) and three times (12, 24, and 36 h) using the hydrothermal treatment and experimental design approach. All samples were characterized by XRD, SEM, FTIR, BET, and NH3-TPD techniques, to evaluate the morphology, crystal size, and surface acidity. The catalytic performance of SAPO-34 zeolites for methanol to light olefins (MTO) was investigated in a fixed-bed reactor at 410 ◦C. According to catalytic results, all prepared catalysts showed similar trends, but olefin selectivity and lifetime were greatly different. Catalysts synthesized at 170 °C and 24 h because of their high crystallinity, the small size of crystals and high surface area showed relatively high ethylene and propylene selectivity of 48.71% and 32.6%, respectively. Sample with low crystallinity, synthesized at 210 °C, and 36 h because of the existing high value of the SAPO-5 and amorphous phase, deactivate rapidly. Comparing with the other sample, the sample synthesized at 170 °C and 12 h because of high crystallinity, mild acidity, and small crystal size possesses a longer lifetime. Hierarchical nine samples of SAPO-34 Nano catalysts were synthesized, at three temperatures (170, 190, 210 °C) and three times (12, 24 and 36 h.) using hydrothermal treatment and experimental design approach. Comparing with the other sample, the sample synthesized at 170 °C and 12 h. because of high crystallinity, mild acidity and small crystal size, possesses a longer lifetime.