Ciemięga Agnieszka, Maresz Katarzyna, Mrowiec-Białoń Julita
Institute of Chemical Engineering, Polish Academy of Sciences, Bałtycka 5, Gliwice, 44-100, Poland.
Sci Rep. 2024 Oct 25;14(1):25332. doi: 10.1038/s41598-024-77146-7.
The results on zirconia-amine bifunctional modification of hierarchically porous silica monoliths for continuous-flow processes ar presented. The study reports the synthesis and properties of the modified porous monoliths and their performance in the tandem process of deacetalization-Knoevenagel condensation reaction. The properties of the materials were studied by thermal analysis, FTIR spectroscopy, XRF and nitrogen adsorption. It was found that both active centres were uniformly distributed along the monolithic cores, and the antagonistic interaction of the acid and base centres was not observed. It was shown that hydrophobicity of the monolith surface has opposite effects on the efficiency of the studied reactions. The overall rate of the tandem process depends on the rate of the condensation reaction. The performance of the bifunctional microreactors was checked and compared with those of cascade-connected monofunctional microreactors and batch reactor. The yield of cyanocinnamate product obtained in both flow systems was ca. 78%; however, pressure drop in the bimodified reactor was only half of that in the cascade. An effective way of water supply to the reaction system has been proposed. The research demonstrates the benefits of using flow-through structured micro-/mesoreactors in tandem reaction processes.
本文介绍了用于连续流过程的分级多孔二氧化硅整体材料的氧化锆-胺双功能改性结果。该研究报告了改性多孔整体材料的合成、性质及其在缩醛化-克诺文格尔缩合反应串联过程中的性能。通过热分析、傅里叶变换红外光谱、X射线荧光光谱和氮吸附对材料的性质进行了研究。结果发现，两个活性中心均沿整体材料核心均匀分布，且未观察到酸碱中心之间的拮抗相互作用。结果表明，整体材料表面的疏水性对所研究反应的效率有相反的影响。串联过程的总速率取决于缩合反应的速率。对双功能微反应器的性能进行了检测，并与级联连接的单功能微反应器和间歇式反应器进行了比较。在两种流动系统中获得的肉桂酸腈产物的产率约为78%；然而，双改性反应器中的压降仅为级联反应器中的一半。提出了一种向反应系统供水的有效方法。该研究证明了在串联反应过程中使用流通式结构化微/介孔反应器的优势。
