Sn-MFI zeolite is one kind of remarkable emerging solid Lewis acid catalyst with high stability in recent years, due to its wide application in the environmental-friendly biomass conversion and catalytic oxidation processes. Herein, it is confirmed that the Sn species are highly dispersed in the matrix of zeolite, and the expansion of unit cell is attributed to the formation of crystalline SnOSi bonds, owing to the size difference between Si and Sn atoms. Due to the charge difference, Sn-MFI zeolites possess much more Lewis acid sites than Silicalite-1 and SnO₂/Silicalite-1, and the catalytic property is closely related to the amount of Lewis acid sites. Consequently, it is reasonable to infer that the Sn atoms are inserted into the framework of Sn-MFI zeolite, in tetrahedral coordination, which acts as the active sites in Lewis acid catalyzed reactions.

Sn-MFI沸石由于其在环境友好型生物质转化和催化氧化过程中的广泛应用，近年来是一种具有高稳定性的杰出新兴固体路易斯酸催化剂。在此，证实了Sn种类高度分散在沸石的基质中，并且由于Si和Sn原子之间的尺寸差异，晶胞的膨胀归因于结晶Sn O Si键的形成。由于电荷差异，Sn-MFI沸石比Silicalite-1和SnO ₂具有更多的路易斯酸位/ Silicalite-1，其催化性能与路易斯酸位点的数量密切相关。因此，可以合理地推断出，锡原子以四面体配位形式插入到Sn-MFI沸石的骨架中，该骨架在路易斯酸催化的反应中充当活性位点。