Continuous-flow synthesis of 4-aminophenol through integrated catalytic reduction and catalyst separation in a hybrid membrane process enabled by Re-, Os-, and W-based microsphere catalysts
Makaleler > Tam Makale · 2026
Yazarlar: Tomasz Piotrowski, Joanna Wolska, Mateusz M.Marzec, Magdalena Wojtas, Zuzanna Oświecińska, Krystian Sokolowski, Katarzyna Berent, Anna Leśniewicz, Andrzej Bernasik, Marek Bryjak, Nalan Kabay, Piotr Cyganowski
Separation and Purification Technology, Uluslararası, Wos, 2026, cilt 412, ss 139560-139560
DOI: 10.1016/j.seppur.2026.139560
Özet
A hybrid membrane-catalytic process was developed for the continuous-flow synthesis of 4-aminophenol (4-AP) via reduction of 4-nitrophenol (4-NP). The system integrates dispersed heterogeneous catalysis with microfiltration-based separation, enabling simultaneous reaction and product purification within a single unit operation. Polymeric microsphere catalysts based on vinylbenzyl chloride–divinylbenzene (VBC-co-DVB) matrices were synthesized, functionalized with amines, and loaded with active species of Re, Os, and W. Structural characterization confirmed the formation of highly dispersed metal species within the polymer network. The catalysts exhibited high activity in the NaBH 4 -assisted reduction of 4-NP, following apparent pseudo-first-order kinetics, with rate constants up to 0.758 min-1. The Os-based microspheres exhibited the highest activity, while the W-based systems showed a higher turnover frequency. When implemented in the hybrid membrane reactor, the catalysts enabled continuous operation with high 4-NP conversion. A complete conversion and a stable operation without breakthrough were achieved for the Os-based system, yielding the catalyst-free 4-AP directly in permeate. Compared to conventional flow systems, the proposed approach combines the advantages of dispersed catalysts with effective phase separation, elimination of mass-transfer limitations, and downstream purification. This work demonstrates a process-intensified strategy for the efficient and scalable synthesis of aromatic amines.