Synthesis of SAPO-34 with only Si(4Al) species: Effect of Si contents on Si incorporation mechanism and Si coordination environment of SAPO-34

• Published in: Microporous and mesoporous materials 2008-11, Vol.115 (3), p.332-337
• Main Authors: Xu, Lei, Du, Aiping, Wei, Yingxu, Wang, Yingli, Yu, Zhengxi, He, Yanli, Zhang, Xinzhi, Liu, Zhongmin
• Format: Article
• Language: English
• Subjects: Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Porous materials; SAPO-34; Si coordination environment; Si incorporation mechanism
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2008.02.001

SAPO-34 molecular sieves with different Si coordination environment were synthesized by adjusting SiO 2/Al 2O 3 molar ratio in starting gel. The crystal structure, element composition and Si coordination environment of the as-synthesized samples were characterized by XRD, SEM, XRF and NMR. SAPO-34 molecular sieve could be obtained when the SiO 2/Al 2O 3 molar ratio of the starting gel was higher than 0.075. The content and modeling of Si incorporated into SAPO-34 framework varied with the SiO 2/Al 2O 3 molar ratios in the starting gel and different Si chemical environments were formed correspondingly. SAPO-34 with only Si(4Al) coordination structure could be prepared when the SiO 2/Al 2O 3 molar ratio of the starting gel was in range of 0.075–0.15.