Abstract: A series of SAPO⁃34 molecular sieves with different crystallization time were synthesized by hydrothermal method using pseudo⁃boehmite, silica sol and phosphoric acid as raw materials, TEA & TEABr as template. The crystal structure and physicochemical properties of the synthesized SAPO⁃34 molecular sieve were characterized by XRD, SEM and NH3⁃TPD. The catalytic activity of MTO was evaluated in a fixed bed reactor. The results showed that pure phase lamellar SAPO⁃34 molecular sieves were synthesized under different crystallization time. The longer the crystallization time was, the higher the crystallinity was, the greater the lamellar thickness was, and the more the acid centers were. At 450 ℃, 2 h-1, 0.2 MPa, crystallization time 72 h, the SAPO⁃34 molecular sieve had the best MTO catalytic activity with a single⁃pass lifetime 360 min and yield of diene 86.8%.

Key words: SAPO-34 molecular sieve, Laminate, Crystallization time, MTO

摘要： 以拟薄水铝石、硅溶胶和磷酸为原料，三乙胺和四乙基溴化铵为模板剂，改变晶化时间，通过水热法合成了一系列SAPO⁃34分子筛。利用XRD、SEM和NH3⁃TPD等技术对合成的SAPO⁃34分子筛晶相结构和物化性能进行分析表征。在固定床反应器上进行了MTO催化活性评价实验。结果表明，不同晶化时间下均合成了纯相的片层状SAPO⁃34分子筛。晶化时间越长，结晶度越高，片层状厚度随之增加，样品的酸中心数目越多。在反应温度为450 ℃、空速为2 h-1、反应压力为0.2 MPa、晶化时间为72 h的条件下，合成SAPO⁃34分子筛的MTO反应单程寿命达到360 min，双烯收率可达86.8%。

关键词: SAPO?34分子筛, 板层状, 晶化时间, MTO