# Nanofiber Mats as Amine-Functionalized Heterogeneous Catalysts in Continuous Microfluidic Reactor Systems

## TL;DR

Researchers developed amine-functionalized nanofiber mats as efficient catalysts in microfluidic reactors for sustainable chemical synthesis.

## Contribution

A novel electrospun, photo-crosslinked nanofiber catalyst system for microfluidic Knoevenagel reactions is introduced.

## Key findings

- NMR yields of 40–60% and turnover frequencies of 50–80 h−1 were achieved in Knoevenagel reactions.
- The catalyst system showed reproducible performance over three reaction cycles.

## Abstract

The development of sustainable catalysts is the main objective in green chemistry approaches. In this study, a catalytically active polymer based on a tertiary amine was synthesized, functionalized with a photo-crosslinker, and structured into nanofibers via electrospinning technique with polycaprolactone (PCL) as a stabilizing additive. Subsequent photo-crosslinking yielded hierarchically porous polymers with high swelling properties and increased surface areas, thereby improving the accessibility of the immobilized catalytically active sites. The nanofiber mats were incorporated into a microfluidic reactor (MFR) setup and utilized as heterogeneous catalysts for the Knoevenagel reaction of malononitrile with different aldehydes. It was observed that the system demonstrated a substantial improvement in NMR yields (40–60%) and turnover frequencies (50–80 h−1) in comparison to catalytical systems that had been previously published. Reusability studies showed reproducibility of NMR yields over up to three cycles. The obtained results demonstrate the potential of electrospun, photo-crosslinked nanofibers as efficient heterogeneous catalysts in microfluidic synthesis, thus contributing to more sustainable production of valuable malononitrile derivatives.