inGAP Center of Research Based Innovation, University of Oslo, Department of Chemistry, N-0315 Oslo, Norway.
Phys Chem Chem Phys. 2011 Feb 21;13(7):2539-49. doi: 10.1039/c0cp01982h. Epub 2010 Dec 10.
Four 3D 10-ring zeolites, IM-5, TNU-9, ZSM-11 and ZSM-5, with Si/Al = 14-24 and crystal sizes below 2 microns, were tested as catalysts for the methanol to hydrocarbons reaction (MTH) at atmospheric pressure, 350 °C and WHSV = 9 h(-1). All catalysts gave initially full methanol conversion, and showed strikingly similar effluent product selectivities. However, their life-time duration differed significantly, and decreased in the order: ZSM-11 > ZSM-5 ≫ TNU-9 > IM-5. A main difference between the two groups of stability behaviour was the size of cavities formed by channel intersections; larger cavities in TNU-9 and IM-5 leading to polyaromatics formation and a more rapid deactivation compared to ZSM-5 and ZSM-11. Effluent yield-conversion plots suggested that polymethylated benzene intermediates were more important in IM-5 and TNU-9 than in ZSM-5 and ZSM-11, where alkene methylation and cracking reactions seemed to dominate product formation. However, this difference had only minor influence on effluent selectivity.
四种 3D 10 元环沸石，IM-5、TNU-9、ZSM-11 和 ZSM-5，Si/Al = 14-24，晶粒尺寸小于 2 微米，在常压、350°C 和 WHSV = 9 h(-1)下被用作甲醇制烃反应（MTH）的催化剂。所有催化剂最初都实现了甲醇的完全转化，并表现出非常相似的产物选择性。然而，它们的寿命长短有显著差异，按顺序递减为：ZSM-11 > ZSM-5 ≫ TNU-9 > IM-5。两种稳定性行为的主要区别在于通道交叉处形成的空腔大小；TNU-9 和 IM-5 中的较大空腔导致多环芳烃的形成，与 ZSM-5 和 ZSM-11 相比，催化剂失活更快。产物转化率-收率图表明，在 IM-5 和 TNU-9 中，多甲基苯中间体比在 ZSM-5 和 ZSM-11 中更重要，其中烯烃的甲基化和裂化反应似乎主导着产物的形成。然而，这种差异对产物选择性的影响很小。
