Tessonnier Jean-Philippe, Louis Benoît, Walspurger Stephane, Sommer Jean, Ledoux Marc-Jacques, Pham-Huu Cuong
Laboratoire des Matériaux, Surfaces et Procédés pour la Catalyse (LMSPC, UMR 7515 du CNRS), ECPM-ULP, 25, rue Becquerel, F-67087 Strasbourg Cedex 2, France.
J Phys Chem B. 2006 Jun 1;110(21):10390-5. doi: 10.1021/jp0602629.
On the basis of our previous H/D exchange studies devoted to the quantification of the number of Brönsted acid sites in solid acids, we report here an innovative approach to determine both the amount and the localization of Mo atoms inside the Mo/ZSM-5 catalyst, commonly used for the methane dehydroaromatization reaction. The influence of Mo introduction in the MFI framework was studied by means of BET, X-ray diffraction, 27Al magic angle spinning NMR, NH3 temperature-programmed desorption, and H/D isotopic exchange techniques. A dependence was found between the decrease of acidic OH groups and the Mo content. Depending on the Si/Al ratio of the zeolite, i.e., the proximity of two Brönsted acid sites, the Mo atoms substitute a different number of OH groups. Consequently, a chemical structure was proposed to describe the geometry of the Mo complex in the channels of the ZSM-5 zeolite.
基于我们之前致力于定量固体酸中布朗斯特酸位数量的氢/氘交换研究，我们在此报告一种创新方法，用于确定常用于甲烷脱氢芳构化反应的Mo/ZSM - 5催化剂中Mo原子的含量及其位置。通过BET、X射线衍射、27Al魔角旋转核磁共振、NH3程序升温脱附和H/D同位素交换技术研究了Mo引入MFI骨架的影响。发现酸性OH基团的减少与Mo含量之间存在相关性。根据沸石的硅铝比，即两个布朗斯特酸位的接近程度，Mo原子取代不同数量的OH基团。因此，提出了一种化学结构来描述ZSM - 5沸石通道中Mo配合物的几何形状。
