High-silica SAPO-5 with preferred orientation: synthesis, characterization and catalytic applications

✍ Scribed by Lijun Wang; Changwen Guo; Shirun Yan; Xidan Huang; Quanzhi Li

• Book ID: 104430984
• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 375 KB
• Volume: 64
• Category: Article
• ISSN: 1387-1811
• DOI: 10.1016/s1387-1811(03)00482-7

✦ Synopsis

Silicon-rich SAPO-5 samples with preferred orientation were synthesized with a simple template of diethylamine at the crystallization temperature of 573 K and a short crystallization time. 29 Si MAS NMR spectra showed that only SM2 occurred for the sample with Si/Al ratio of 0.25, while SM2 + SM3 occurred for the sample with Si/Al ratio of 0.42. Though there were very few strong acid sites in SAPO-5 framework with Si/Al ratio of 0.25, it showed high n-alkane hydrocracking activity. It also showed unusual catalytic behavior for longer chain hydrocarbons (n-C12, n-C16), which could be adsorbed within SAPO-5 channels below 573 K, while hydrocracked at temperatures higher than 598 K. The 12-ring channels structure of SAPO-5 with preferred orientation is used to explain the unusual results.