The Synthesis of SAPO-34 at Different Crystallization Temperature and its Catalytic Performance for Methanol to Olefins Reaction

In order to enhance the catalytic performance of sapo-34 for the reaction of methanolto light olefins (mto), three different crystallization temperatures were used tosynthesize sapo-34. the catalysts were synthesized hydrothermally with molarcomposition as 1 al2o3: 1 p2o5: 0.4 sio2: 1 teaoh: 0.5 tea: 0.5 mor: 70 h2o. theeffects of the crystallization temperature on the phase purity, morphology andfunctional groups of sapo-34 were characterized by xrd, sem and ftir techniques.the relative crystallinity was decreased by increasing crystallization temperature andsome impurities appeared at high crystallization temperature. all samples showed cubicmorphology with different crystal size. the catalytic performance of synthesized sapo-34 was investigated in a fixed-bed reactor at 410?c. for the mto reaction, allsynthesized catalysts showed similar product distribution and methanol conversion, butlight olefins selectivity was greatly dependent on the crystallization condition. thesample was synthesized at 170?c and 24 h, possessed the highest light olefins due tohighest amount of acid sites, relative crystallinity and smallest mean crystal size.