Gołąbek Kinga, Tabor Edyta, Pashkova Veronika, Dedecek Jiri, Tarach Karolina, Góra-Marek Kinga
Faculty of Chemistry, Jagiellonian University in Kraków, Gronostajowa 2, 30-387, Kraków, Poland.
J. Heyrovský Institute of Physical Chemistry of the CAS, Dolejškova 2155/3, 182 23, Prague 8, Czech Republic.
Commun Chem. 2020 Feb 25;3(1):25. doi: 10.1038/s42004-020-0268-3.
The organization of aluminium atoms in zeolites affects their catalytic properties. Here we demonstrate that the aluminium distribution is a key parameter controlling the reaction pathway of acid catalysed reactions over ZSM-5 zeolites. We study ethanol transformation over two ZSM-5 samples with similar Si/Al ratios of ~15, and with aluminium atoms located mainly at the channel intersections but differently distributed in the framework. One of the samples contains mostly isolated aluminium atoms while the other has a large fraction of two aluminium atoms located in one ring. The FT-IR time-resolved operando study, supported by catalytic results, reveals that the reaction pathway in ethanol transformation over ZSM-5 is controlled by the proximity of aluminium atoms in the framework. ZSM-5 containing mostly isolated Al atoms transforms ethanol in the associative pathway, and conversely ZSM-5 containing a dominating fraction of two aluminium atoms in one ring transforms ethanol in the dissociative pathway.
沸石中铝原子的排列会影响其催化性能。在此我们证明，铝的分布是控制ZSM-5沸石上酸催化反应反应途径的关键参数。我们研究了两种硅铝比约为15且相似的ZSM-5样品上的乙醇转化反应，铝原子主要位于通道交叉处，但在骨架中的分布不同。其中一个样品主要包含孤立的铝原子，而另一个样品有很大一部分两个铝原子位于一个环中。由催化结果支持的傅里叶变换红外光谱时间分辨原位研究表明，ZSM-5上乙醇转化反应的反应途径由骨架中铝原子的 proximity 控制。主要包含孤立铝原子的ZSM-5通过缔合途径转化乙醇，相反，在一个环中包含占主导比例的两个铝原子的ZSM-5通过解离途径转化乙醇。 （注：原文中“proximity”未翻译完整，可能是“邻近度”之类的意思，需结合更多背景知识准确理解。）
