化学学报 ›› 2008, Vol. 66 ›› Issue (7): 769-774. 上一篇    下一篇

研究论文

含有乙醚的无胺无氟反应物体系中高硅丝光沸石的合成

汪靖 程晓维 杨晓蔚 龙英才   

  1. 复旦大学化学系
  • 投稿日期:2007-09-21 修回日期:2007-11-06 发布日期:2008-04-14
  • 通讯作者: 龙英才

Crystallization of High silica MOR zeolite in amine-free and fluoride-free ether-contained reactant system

  

  • Received:2007-09-21 Revised:2007-11-06 Published:2008-04-14

本文研究含有乙醚的Na2O-Al2O3-SiO2-H2O反应物中高硅丝光沸石在413-453K下的水热合成。乙醚的存在能有效促进丝光沸石的结晶过程,且有助于提高产物结晶度和硅铝比。反应物胶体中硅铝比与碱度对产物的生成有关键作用。合成原料使用不同铝源,体系结晶规律相近,但产物的形貌和硅铝比有差异。在优化的反应条件下合成的高硅丝光沸石硅铝比达30左右。低温氮吸附与27Al魔角旋转核磁谱表征证实该沸石骨架结构完美,孔道开放畅通,其水热稳定性优于低硅丝光沸石。

关键词: 高硅, 丝光沸石, 乙醚促进, 无胺, 无氟

Hydrothermal synthesis of high-silica MOR type zeolite at the temperature range of 413-433K was investigated in amine-free and fluoride-free Na2O-Al2O3-SiO2-H2O reactant system using different alumina source in presence of ether, which plays an effectively promoting role on the crystallization and the increasing the molar ratio of silica to alumina (SAR) for the zeolite. SAR and the alkalinity in the starting reactant gel make essential effects on the crystallization of the zeolite with pure phase. The crystallization phenomena in the reactant prepared with different alumina sources are similar, except obvious differences on the morphology and SAR of the as-synthesized MOR zeolites. Pure phase MOR zeolite with SAR up to 30 was obtained in the reactant with optimum compositions and under a certain reaction condition. Characterized by nitrogen sorption and 27Al magic–angle spinning (MAS) nuclear magnetic resonance (NMR), perfect framework and open channel system of the zeolite has been proved. The high silica MOR zeolite exhibits much more excellent hydrothermal stability in comparison of the low SAR one.