Crystallographic sites of Brönsted acids (Si-OH-Al) in zeolites, which are closely associated with the Al sites, play a significant and unique role in the catalytic application, especially when they are distributed in open channel systems or confined in cavities with small pore openings. In this article, we unraveled constrained Al crystallographic sites in FER-type zeolites containing the distinct local environments (10-ring channels and ferrierite cavities) by Rietveld refinement against the powder X-ray diffraction data. Final refinement demonstrates that regardless of the types of structure-directing agents and synthetic medium utilized, T1 and/or T3 are Al-rich positions, which are further confirmed by theoretical calculations. This new finding of constrained Al sites in the FER-type zeolite can well explain its limited catalytic activity in the DME carbonylation reaction.

沸石中布朗斯台德酸 (Si-OH-Al) 的结晶位点与 Al 位点密切相关，在催化应用中发挥着重要而独特的作用，尤其是当它们分布在开放通道系统中或被限制在具有小毛孔开口。在这篇文章中，我们通过 Rietveld 细化针对粉末 X 射线衍射数据解开了包含不同局部环境（10 环通道和镁碱沸石空腔）的 FER 型沸石中受约束的 Al 晶体学位点。最终的改进表明，无论使用的结构导向剂和合成介质的类型如何，T1 和/或 T3 都是富含铝的位置，理论计算进一步证实了这一点。