Dual-Temperature Crystallization Synthesis of Secondary-Growth SAPO-34 Molecular Sieve with Adjusted Silicon Content for Superior MTO Catalysis

Based on the dual-temperature method (100 ℃ for 6 h and then 200 ℃ for 12 h), the novel surface modification strategy involving secondary growth with the pre-synthesized nano-flake SAPO-34 seeds is presented for the synthesis of hierarchical pore SAPO-34. The effective regulation of the silicon content in the initial gel modulated the pore architecture and the acid strength of the SAPO-34 product. The optimized catalyst demonstrated a superior selectivity for the light olefins and a suppression of the coke deposition, leading to a prolonged catalytic lifetime. The catalytic performance showed a trend of first increasing and then decreasing with the silicon content. The optimal catalyst demonstrated an excellent selectivity of 95.88% and an extended lifetime of 600 min. Graphical The alternative text for this image may have been generated using AI.