A green and cost-effective surfactant-assisted synthesis of SAPO-34 using dual microporous templates with improved performance in MTO reaction

The SAPO-34 catalysts were successfully synthesized with different amounts of a cheap and green nonionic surfactant (Triton X-100) as a mesoporogen additive and MOR/TEAOH as microporous mixed templates. The prepared samples were characterized and tested in the methanol to olefins (MTO) reaction under the industrial feed composition of 72 wt% methanol in water. The results revealed that the surfactant concentration affects the acidity, particle size, and textural properties which results in different catalytic performances. The sample prepared with the surfactant molar ratio of 0.02 exhibits a 12% improvement in the light olefins selectivity (90%) as well as the longer catalyst lifetime (more than 330 min) compared to the parent one (79.3% selectivity and 260 min lifetime). This could be attributed to the high crystallinity, smaller crystallite size, proper lower acidity, higher surface area, and the facilitation of reactants and product transportation through mesoporosity created in the structure of crystals. Hierarchical SAPO-34 molecular sieve was synthesized with different amounts of triton X-100 (0, 0.02, 0.04, and 0.06) as a green and cost-effective surfactant. The catalytic performance of samples carried out under industrial feed composition (72 wt% MeOH in water). The SP-34 (0.02) sample prepared with 0.02 molar ratio of triton X-100/Al(2)O(3)showed the best performance among all the catalysts (90% total light olefins and more than 330 min lifetime).