Ethylenediamine Assisted Synthesis of Sn-MFI Zeolite with High Space-Time Yield as Lewis Acidic Catalysts for Conversion of Dihydroxypropanone to Methyl Lactate

The efficient preparation of catalyst is an important topic for its industrial application. The Sn-containing zeolite is one kind of important catalysts for many catalytic conversions of oxygenated chemicals. In this work, an efficient strategy for preparation of Sn-MFI zeolite was developed, of which space-time yield can reach 62.58 kg/m(3).h, which is 120 times higher than that of typical hydrothermal route (0.53 kg/m(3).h). Combining XRD, TEM, XPS, FT-IR, Si-29 NMR and other characterization methods, the framework tin sites were confirmed, and key role of ethylenediamine (EDA) for formation of which was revealed. Additionally, the framework tin sites content and catalytic activity of the Sn-MFI prepared by this strategy is comparable to that of Sn-MFI-hy prepared by typical route in the conversion of dihydroxypropanone (DHA) to methyl lactate (ML), which gives ML yield of 80.64 % under optimized conditions. The proposed methodology can be extended to other types of Sn-containing zeolite, which will certainly promote its industrial application.