Silicalite-1 for Glycerol Acetalization

Silicalite-1 is a high silica MFI structure type zeolite with no noticeable catalytically active (e.g., acid) sites. Modification with solutions of NH4F of varying concentrations generates in Silicalite-1 efficient and selective acid sites for the acetalization of glycerol with acetone towards solketal. The modified materials were characterized using adequate techniques (i.e., XRD, SEM, TEM, FTIR). It was shown that the newly created acidic sites, characterized by significantly higher acidic strength and enhanced accessibility for reagents compared to the pristine one, demonstrate exceptional catalytic activity in the acetalization of glycerol with acetone, displaying notable selectivity towards solketal.全硅沸石-1（Silicalite-1）是一种高硅MFI结构型沸石，无显著催化活性位点（如酸性位点）。通过不同浓度的氟化铵（NH4F）溶液对其进行改性，可在该材料中构建出高效且具有选择性的酸性位点，用于甘油与丙酮的缩醛化反应以制备索开塔尔（solketal）。研究采用合适的表征技术对改性后的材料进行了表征，具体包括X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）以及傅里叶变换红外光谱（FTIR）。结果表明，相较于原始未改性样品，新构建的酸性位点具备显著更高的酸强度与更优良的反应物可及性，在甘油与丙酮的缩醛化反应中展现出优异的催化活性，且对索开塔尔（solketal）呈现出突出的选择性。