Abstract
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.
| Original language | English |
|---|---|
| Pages (from-to) | 15099-15102 |
| Journal | Chemistry - A European Journal |
| Volume | 26 |
| Issue number | 66 |
| DOIs | |
| Publication status | Published - 26 Nov 2020 |
Funding
Thomas van Swieten (Utrecht University) is acknowledged for his help with the thermoluminescence experiments. Dr. Jeroen Vollenbroek (University of Twente, UT) and Dr. Mathieu Odijk (UT) are acknowledged for their input and fruitful discussions. This work was supported by a VIDI grant of the Dutch Research Council (NWO) as well as by the Netherlands Center for Multiscale Catalytic Energy Conversion (MCEC), an NWO gravitation program funded by the Ministry of Education, Culture and Science of the government of the Netherlands and by the Dutch Research Council (NWO).
Keywords
- biphasic catalysis
- droplet microfluidics
- Pickering emulsions
- Raman spectroscopy