Vis Carolien M, Nieuwelink Anne-Eva, Weckhuysen Bert M, Bruijnincx Pieter C A
Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, The Netherlands.
Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, The Netherlands.
Chemistry. 2020 Nov 26;26(66):15099-15102. doi: 10.1002/chem.202002479. Epub 2020 Oct 15.
Pickering emulsions (PEs), emulsions stabilized by solid particles, have shown to be a versatile tool for biphasic catalysis. Here, we report a droplet microfluidic approach for flow PE (FPE) catalysis, further expanding the possibilities for PE catalysis beyond standard batch PE reactions. This microreactor allowed for the inline analysis of the catalytic process with in situ Raman spectroscopy, as demonstrated for the acid-catalyzed deacetalization of benzaldehyde dimethyl acetal to form benzaldehyde. Furthermore, the use of the FPE system showed a nine fold improvement in yield compared to the simple biphasic flow system (FBS), highlighting the advantage of emulsification. Finally, FPE allowed an antagonistic set of reactions, the deacetalization-Knoevenagel condensation, which proved less efficient in FBS due to rapid acid-base quenching. The droplet microfluidic system thus offers a versatile new extension of PE catalysis.
皮克林乳液（PEs）是由固体颗粒稳定的乳液，已被证明是一种用于双相催化的多功能工具。在此，我们报告了一种用于流动PE（FPE）催化的液滴微流控方法，进一步拓展了PE催化在标准间歇式PE反应之外的可能性。这种微反应器允许通过原位拉曼光谱对催化过程进行在线分析，以苯甲醛二甲醇缩醛酸催化脱缩醛化生成苯甲醛为例进行了演示。此外，与简单的双相流动系统（FBS）相比，FPE系统的产率提高了九倍，突出了乳化的优势。最后，FPE实现了一组拮抗反应，即脱缩醛化-克诺文纳格尔缩合反应，该反应在FBS中由于酸碱快速淬灭而效率较低。因此，液滴微流控系统为PE催化提供了一种多功能新扩展。
